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Diffstat (limited to 'Documentation')
83 files changed, 2423 insertions, 1261 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index a986e9bbba3..bcebb9eaedc 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -160,7 +160,7 @@ Description: match the driver to the device. For example: # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id -What: /sys/bus/usb/device/.../avoid_reset +What: /sys/bus/usb/device/.../avoid_reset_quirk Date: December 2009 Contact: Oliver Neukum <oliver@neukum.org> Description: diff --git a/Documentation/PCI/PCI-DMA-mapping.txt b/Documentation/DMA-API-HOWTO.txt index ecad88d9fe5..52618ab069a 100644 --- a/Documentation/PCI/PCI-DMA-mapping.txt +++ b/Documentation/DMA-API-HOWTO.txt @@ -1,12 +1,12 @@ - Dynamic DMA mapping - =================== + Dynamic DMA mapping Guide + ========================= David S. Miller <davem@redhat.com> Richard Henderson <rth@cygnus.com> Jakub Jelinek <jakub@redhat.com> -This document describes the DMA mapping system in terms of the pci_ -API. For a similar API that works for generic devices, see +This is a guide to device driver writers on how to use the DMA API +with example pseudo-code. For a concise description of the API, see DMA-API.txt. Most of the 64bit platforms have special hardware that translates bus @@ -26,12 +26,15 @@ mapped only for the time they are actually used and unmapped after the DMA transfer. The following API will work of course even on platforms where no such -hardware exists, see e.g. arch/x86/include/asm/pci.h for how it is implemented on -top of the virt_to_bus interface. +hardware exists. + +Note that the DMA API works with any bus independent of the underlying +microprocessor architecture. You should use the DMA API rather than +the bus specific DMA API (e.g. pci_dma_*). First of all, you should make sure -#include <linux/pci.h> +#include <linux/dma-mapping.h> is in your driver. This file will obtain for you the definition of the dma_addr_t (which can hold any valid DMA address for the platform) @@ -78,44 +81,43 @@ for you to DMA from/to. DMA addressing limitations Does your device have any DMA addressing limitations? For example, is -your device only capable of driving the low order 24-bits of address -on the PCI bus for SAC DMA transfers? If so, you need to inform the -PCI layer of this fact. +your device only capable of driving the low order 24-bits of address? +If so, you need to inform the kernel of this fact. By default, the kernel assumes that your device can address the full -32-bits in a SAC cycle. For a 64-bit DAC capable device, this needs -to be increased. And for a device with limitations, as discussed in -the previous paragraph, it needs to be decreased. - -pci_alloc_consistent() by default will return 32-bit DMA addresses. -PCI-X specification requires PCI-X devices to support 64-bit -addressing (DAC) for all transactions. And at least one platform (SGI -SN2) requires 64-bit consistent allocations to operate correctly when -the IO bus is in PCI-X mode. Therefore, like with pci_set_dma_mask(), -it's good practice to call pci_set_consistent_dma_mask() to set the -appropriate mask even if your device only supports 32-bit DMA -(default) and especially if it's a PCI-X device. - -For correct operation, you must interrogate the PCI layer in your -device probe routine to see if the PCI controller on the machine can -properly support the DMA addressing limitation your device has. It is -good style to do this even if your device holds the default setting, +32-bits. For a 64-bit capable device, this needs to be increased. +And for a device with limitations, as discussed in the previous +paragraph, it needs to be decreased. + +Special note about PCI: PCI-X specification requires PCI-X devices to +support 64-bit addressing (DAC) for all transactions. And at least +one platform (SGI SN2) requires 64-bit consistent allocations to +operate correctly when the IO bus is in PCI-X mode. + +For correct operation, you must interrogate the kernel in your device +probe routine to see if the DMA controller on the machine can properly +support the DMA addressing limitation your device has. It is good +style to do this even if your device holds the default setting, because this shows that you did think about these issues wrt. your device. -The query is performed via a call to pci_set_dma_mask(): +The query is performed via a call to dma_set_mask(): - int pci_set_dma_mask(struct pci_dev *pdev, u64 device_mask); + int dma_set_mask(struct device *dev, u64 mask); The query for consistent allocations is performed via a call to -pci_set_consistent_dma_mask(): +dma_set_coherent_mask(): - int pci_set_consistent_dma_mask(struct pci_dev *pdev, u64 device_mask); + int dma_set_coherent_mask(struct device *dev, u64 mask); -Here, pdev is a pointer to the PCI device struct of your device, and -device_mask is a bit mask describing which bits of a PCI address your -device supports. It returns zero if your card can perform DMA -properly on the machine given the address mask you provided. +Here, dev is a pointer to the device struct of your device, and mask +is a bit mask describing which bits of an address your device +supports. It returns zero if your card can perform DMA properly on +the machine given the address mask you provided. In general, the +device struct of your device is embedded in the bus specific device +struct of your device. For example, a pointer to the device struct of +your PCI device is pdev->dev (pdev is a pointer to the PCI device +struct of your device). If it returns non-zero, your device cannot perform DMA properly on this platform, and attempting to do so will result in undefined @@ -133,31 +135,30 @@ of your driver reports that performance is bad or that the device is not even detected, you can ask them for the kernel messages to find out exactly why. -The standard 32-bit addressing PCI device would do something like -this: +The standard 32-bit addressing device would do something like this: - if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) { + if (dma_set_mask(dev, DMA_BIT_MASK(32))) { printk(KERN_WARNING "mydev: No suitable DMA available.\n"); goto ignore_this_device; } -Another common scenario is a 64-bit capable device. The approach -here is to try for 64-bit DAC addressing, but back down to a -32-bit mask should that fail. The PCI platform code may fail the -64-bit mask not because the platform is not capable of 64-bit -addressing. Rather, it may fail in this case simply because -32-bit SAC addressing is done more efficiently than DAC addressing. -Sparc64 is one platform which behaves in this way. +Another common scenario is a 64-bit capable device. The approach here +is to try for 64-bit addressing, but back down to a 32-bit mask that +should not fail. The kernel may fail the 64-bit mask not because the +platform is not capable of 64-bit addressing. Rather, it may fail in +this case simply because 32-bit addressing is done more efficiently +than 64-bit addressing. For example, Sparc64 PCI SAC addressing is +more efficient than DAC addressing. Here is how you would handle a 64-bit capable device which can drive all 64-bits when accessing streaming DMA: int using_dac; - if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) { + if (!dma_set_mask(dev, DMA_BIT_MASK(64))) { using_dac = 1; - } else if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) { + } else if (!dma_set_mask(dev, DMA_BIT_MASK(32))) { using_dac = 0; } else { printk(KERN_WARNING @@ -170,36 +171,36 @@ the case would look like this: int using_dac, consistent_using_dac; - if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) { + if (!dma_set_mask(dev, DMA_BIT_MASK(64))) { using_dac = 1; consistent_using_dac = 1; - pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)); - } else if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) { + dma_set_coherent_mask(dev, DMA_BIT_MASK(64)); + } else if (!dma_set_mask(dev, DMA_BIT_MASK(32))) { using_dac = 0; consistent_using_dac = 0; - pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32)); + dma_set_coherent_mask(dev, DMA_BIT_MASK(32)); } else { printk(KERN_WARNING "mydev: No suitable DMA available.\n"); goto ignore_this_device; } -pci_set_consistent_dma_mask() will always be able to set the same or a -smaller mask as pci_set_dma_mask(). However for the rare case that a +dma_set_coherent_mask() will always be able to set the same or a +smaller mask as dma_set_mask(). However for the rare case that a device driver only uses consistent allocations, one would have to -check the return value from pci_set_consistent_dma_mask(). +check the return value from dma_set_coherent_mask(). Finally, if your device can only drive the low 24-bits of -address during PCI bus mastering you might do something like: +address you might do something like: - if (pci_set_dma_mask(pdev, DMA_BIT_MASK(24))) { + if (dma_set_mask(dev, DMA_BIT_MASK(24))) { printk(KERN_WARNING "mydev: 24-bit DMA addressing not available.\n"); goto ignore_this_device; } -When pci_set_dma_mask() is successful, and returns zero, the PCI layer -saves away this mask you have provided. The PCI layer will use this +When dma_set_mask() is successful, and returns zero, the kernel saves +away this mask you have provided. The kernel will use this information later when you make DMA mappings. There is a case which we are aware of at this time, which is worth @@ -208,7 +209,7 @@ functions (for example a sound card provides playback and record functions) and the various different functions have _different_ DMA addressing limitations, you may wish to probe each mask and only provide the functionality which the machine can handle. It -is important that the last call to pci_set_dma_mask() be for the +is important that the last call to dma_set_mask() be for the most specific mask. Here is pseudo-code showing how this might be done: @@ -217,17 +218,17 @@ Here is pseudo-code showing how this might be done: #define RECORD_ADDRESS_BITS DMA_BIT_MASK(24) struct my_sound_card *card; - struct pci_dev *pdev; + struct device *dev; ... - if (!pci_set_dma_mask(pdev, PLAYBACK_ADDRESS_BITS)) { + if (!dma_set_mask(dev, PLAYBACK_ADDRESS_BITS)) { card->playback_enabled = 1; } else { card->playback_enabled = 0; printk(KERN_WARNING "%s: Playback disabled due to DMA limitations.\n", card->name); } - if (!pci_set_dma_mask(pdev, RECORD_ADDRESS_BITS)) { + if (!dma_set_mask(dev, RECORD_ADDRESS_BITS)) { card->record_enabled = 1; } else { card->record_enabled = 0; @@ -252,8 +253,8 @@ There are two types of DMA mappings: Think of "consistent" as "synchronous" or "coherent". The current default is to return consistent memory in the low 32 - bits of the PCI bus space. However, for future compatibility you - should set the consistent mask even if this default is fine for your + bits of the bus space. However, for future compatibility you should + set the consistent mask even if this default is fine for your driver. Good examples of what to use consistent mappings for are: @@ -285,9 +286,9 @@ There are two types of DMA mappings: found in PCI bridges (such as by reading a register's value after writing it). -- Streaming DMA mappings which are usually mapped for one DMA transfer, - unmapped right after it (unless you use pci_dma_sync_* below) and for which - hardware can optimize for sequential accesses. +- Streaming DMA mappings which are usually mapped for one DMA + transfer, unmapped right after it (unless you use dma_sync_* below) + and for which hardware can optimize for sequential accesses. This of "streaming" as "asynchronous" or "outside the coherency domain". @@ -302,8 +303,8 @@ There are two types of DMA mappings: optimizations the hardware allows. To this end, when using such mappings you must be explicit about what you want to happen. -Neither type of DMA mapping has alignment restrictions that come -from PCI, although some devices may have such restrictions. +Neither type of DMA mapping has alignment restrictions that come from +the underlying bus, although some devices may have such restrictions. Also, systems with caches that aren't DMA-coherent will work better when the underlying buffers don't share cache lines with other data. @@ -315,33 +316,27 @@ you should do: dma_addr_t dma_handle; - cpu_addr = pci_alloc_consistent(pdev, size, &dma_handle); - -where pdev is a struct pci_dev *. This may be called in interrupt context. -You should use dma_alloc_coherent (see DMA-API.txt) for buses -where devices don't have struct pci_dev (like ISA, EISA). + cpu_addr = dma_alloc_coherent(dev, size, &dma_handle, gfp); -This argument is needed because the DMA translations may be bus -specific (and often is private to the bus which the device is attached -to). +where device is a struct device *. This may be called in interrupt +context with the GFP_ATOMIC flag. Size is the length of the region you want to allocate, in bytes. This routine will allocate RAM for that region, so it acts similarly to __get_free_pages (but takes size instead of a page order). If your driver needs regions sized smaller than a page, you may prefer using -the pci_pool interface, described below. - -The consistent DMA mapping interfaces, for non-NULL pdev, will by -default return a DMA address which is SAC (Single Address Cycle) -addressable. Even if the device indicates (via PCI dma mask) that it -may address the upper 32-bits and thus perform DAC cycles, consistent -allocation will only return > 32-bit PCI addresses for DMA if the -consistent dma mask has been explicitly changed via -pci_set_consistent_dma_mask(). This is true of the pci_pool interface -as well. - -pci_alloc_consistent returns two values: the virtual address which you +the dma_pool interface, described below. + +The consistent DMA mapping interfaces, for non-NULL dev, will by +default return a DMA address which is 32-bit addressable. Even if the +device indicates (via DMA mask) that it may address the upper 32-bits, +consistent allocation will only return > 32-bit addresses for DMA if +the consistent DMA mask has been explicitly changed via +dma_set_coherent_mask(). This is true of the dma_pool interface as +well. + +dma_alloc_coherent returns two values: the virtual address which you can use to access it from the CPU and dma_handle which you pass to the card. @@ -354,54 +349,54 @@ buffer you receive will not cross a 64K boundary. To unmap and free such a DMA region, you call: - pci_free_consistent(pdev, size, cpu_addr, dma_handle); + dma_free_coherent(dev, size, cpu_addr, dma_handle); -where pdev, size are the same as in the above call and cpu_addr and -dma_handle are the values pci_alloc_consistent returned to you. +where dev, size are the same as in the above call and cpu_addr and +dma_handle are the values dma_alloc_coherent returned to you. This function may not be called in interrupt context. If your driver needs lots of smaller memory regions, you can write -custom code to subdivide pages returned by pci_alloc_consistent, -or you can use the pci_pool API to do that. A pci_pool is like -a kmem_cache, but it uses pci_alloc_consistent not __get_free_pages. +custom code to subdivide pages returned by dma_alloc_coherent, +or you can use the dma_pool API to do that. A dma_pool is like +a kmem_cache, but it uses dma_alloc_coherent not __get_free_pages. Also, it understands common hardware constraints for alignment, like queue heads needing to be aligned on N byte boundaries. -Create a pci_pool like this: +Create a dma_pool like this: - struct pci_pool *pool; + struct dma_pool *pool; - pool = pci_pool_create(name, pdev, size, align, alloc); + pool = dma_pool_create(name, dev, size, align, alloc); -The "name" is for diagnostics (like a kmem_cache name); pdev and size +The "name" is for diagnostics (like a kmem_cache name); dev and size are as above. The device's hardware alignment requirement for this type of data is "align" (which is expressed in bytes, and must be a power of two). If your device has no boundary crossing restrictions, pass 0 for alloc; passing 4096 says memory allocated from this pool must not cross 4KByte boundaries (but at that time it may be better to -go for pci_alloc_consistent directly instead). +go for dma_alloc_coherent directly instead). -Allocate memory from a pci pool like this: +Allocate memory from a dma pool like this: - cpu_addr = pci_pool_alloc(pool, flags, &dma_handle); + cpu_addr = dma_pool_alloc(pool, flags, &dma_handle); flags are SLAB_KERNEL if blocking is permitted (not in_interrupt nor -holding SMP locks), SLAB_ATOMIC otherwise. Like pci_alloc_consistent, +holding SMP locks), SLAB_ATOMIC otherwise. Like dma_alloc_coherent, this returns two values, cpu_addr and dma_handle. -Free memory that was allocated from a pci_pool like this: +Free memory that was allocated from a dma_pool like this: - pci_pool_free(pool, cpu_addr, dma_handle); + dma_pool_free(pool, cpu_addr, dma_handle); -where pool is what you passed to pci_pool_alloc, and cpu_addr and -dma_handle are the values pci_pool_alloc returned. This function +where pool is what you passed to dma_pool_alloc, and cpu_addr and +dma_handle are the values dma_pool_alloc returned. This function may be called in interrupt context. -Destroy a pci_pool by calling: +Destroy a dma_pool by calling: - pci_pool_destroy(pool); + dma_pool_destroy(pool); -Make sure you've called pci_pool_free for all memory allocated +Make sure you've called dma_pool_free for all memory allocated from a pool before you destroy the pool. This function may not be called in interrupt context. @@ -411,15 +406,15 @@ The interfaces described in subsequent portions of this document take a DMA direction argument, which is an integer and takes on one of the following values: - PCI_DMA_BIDIRECTIONAL - PCI_DMA_TODEVICE - PCI_DMA_FROMDEVICE - PCI_DMA_NONE + DMA_BIDIRECTIONAL + DMA_TO_DEVICE + DMA_FROM_DEVICE + DMA_NONE One should provide the exact DMA direction if you know it. -PCI_DMA_TODEVICE means "from main memory to the PCI device" -PCI_DMA_FROMDEVICE means "from the PCI device to main memory" +DMA_TO_DEVICE means "from main memory to the device" +DMA_FROM_DEVICE means "from the device to main memory" It is the direction in which the data moves during the DMA transfer. @@ -427,12 +422,12 @@ You are _strongly_ encouraged to specify this as precisely as you possibly can. If you absolutely cannot know the direction of the DMA transfer, -specify PCI_DMA_BIDIRECTIONAL. It means that the DMA can go in +specify DMA_BIDIRECTIONAL. It means that the DMA can go in either direction. The platform guarantees that you may legally specify this, and that it will work, but this may be at the cost of performance for example. -The value PCI_DMA_NONE is to be used for debugging. One can +The value DMA_NONE is to be used for debugging. One can hold this in a data structure before you come to know the precise direction, and this will help catch cases where your direction tracking logic has failed to set things up properly. @@ -442,21 +437,21 @@ potential platform-specific optimizations of such) is for debugging. Some platforms actually have a write permission boolean which DMA mappings can be marked with, much like page protections in the user program address space. Such platforms can and do report errors in the -kernel logs when the PCI controller hardware detects violation of the +kernel logs when the DMA controller hardware detects violation of the permission setting. Only streaming mappings specify a direction, consistent mappings implicitly have a direction attribute setting of -PCI_DMA_BIDIRECTIONAL. +DMA_BIDIRECTIONAL. The SCSI subsystem tells you the direction to use in the 'sc_data_direction' member of the SCSI command your driver is working on. For Networking drivers, it's a rather simple affair. For transmit -packets, map/unmap them with the PCI_DMA_TODEVICE direction +packets, map/unmap them with the DMA_TO_DEVICE direction specifier. For receive packets, just the opposite, map/unmap them -with the PCI_DMA_FROMDEVICE direction specifier. +with the DMA_FROM_DEVICE direction specifier. Using Streaming DMA mappings @@ -467,43 +462,43 @@ scatterlist. To map a single region, you do: - struct pci_dev *pdev = mydev->pdev; + struct device *dev = &my_dev->dev; dma_addr_t dma_handle; void *addr = buffer->ptr; size_t size = buffer->len; - dma_handle = pci_map_single(pdev, addr, size, direction); + dma_handle = dma_map_single(dev, addr, size, direction); and to unmap it: - pci_unmap_single(pdev, dma_handle, size, direction); + dma_unmap_single(dev, dma_handle, size, direction); -You should call pci_unmap_single when the DMA activity is finished, e.g. +You should call dma_unmap_single when the DMA activity is finished, e.g. from the interrupt which told you that the DMA transfer is done. Using cpu pointers like this for single mappings has a disadvantage, you cannot reference HIGHMEM memory in this way. Thus, there is a -map/unmap interface pair akin to pci_{map,unmap}_single. These +map/unmap interface pair akin to dma_{map,unmap}_single. These interfaces deal with page/offset pairs instead of cpu pointers. Specifically: - struct pci_dev *pdev = mydev->pdev; + struct device *dev = &my_dev->dev; dma_addr_t dma_handle; struct page *page = buffer->page; unsigned long offset = buffer->offset; size_t size = buffer->len; - dma_handle = pci_map_page(pdev, page, offset, size, direction); + dma_handle = dma_map_page(dev, page, offset, size, direction); ... - pci_unmap_page(pdev, dma_handle, size, direction); + dma_unmap_page(dev, dma_handle, size, direction); Here, "offset" means byte offset within the given page. With scatterlists, you map a region gathered from several regions by: - int i, count = pci_map_sg(pdev, sglist, nents, direction); + int i, count = dma_map_sg(dev, sglist, nents, direction); struct scatterlist *sg; for_each_sg(sglist, sg, count, i) { @@ -527,16 +522,16 @@ accessed sg->address and sg->length as shown above. To unmap a scatterlist, just call: - pci_unmap_sg(pdev, sglist, nents, direction); + dma_unmap_sg(dev, sglist, nents, direction); Again, make sure DMA activity has already finished. -PLEASE NOTE: The 'nents' argument to the pci_unmap_sg call must be - the _same_ one you passed into the pci_map_sg call, +PLEASE NOTE: The 'nents' argument to the dma_unmap_sg call must be + the _same_ one you passed into the dma_map_sg call, it should _NOT_ be the 'count' value _returned_ from the - pci_map_sg call. + dma_map_sg call. -Every pci_map_{single,sg} call should have its pci_unmap_{single,sg} +Every dma_map_{single,sg} call should have its dma_unmap_{single,sg} counterpart, because the bus address space is a shared resource (although in some ports the mapping is per each BUS so less devices contend for the same bus address space) and you could render the machine unusable by eating @@ -547,14 +542,14 @@ the data in between the DMA transfers, the buffer needs to be synced properly in order for the cpu and device to see the most uptodate and correct copy of the DMA buffer. -So, firstly, just map it with pci_map_{single,sg}, and after each DMA +So, firstly, just map it with dma_map_{single,sg}, and after each DMA transfer call either: - pci_dma_sync_single_for_cpu(pdev, dma_handle, size, direction); + dma_sync_single_for_cpu(dev, dma_handle, size, direction); or: - pci_dma_sync_sg_for_cpu(pdev, sglist, nents, direction); + dma_sync_sg_for_cpu(dev, sglist, nents, direction); as appropriate. @@ -562,27 +557,27 @@ Then, if you wish to let the device get at the DMA area again, finish accessing the data with the cpu, and then before actually giving the buffer to the hardware call either: - pci_dma_sync_single_for_device(pdev, dma_handle, size, direction); + dma_sync_single_for_device(dev, dma_handle, size, direction); or: - pci_dma_sync_sg_for_device(dev, sglist, nents, direction); + dma_sync_sg_for_device(dev, sglist, nents, direction); as appropriate. After the last DMA transfer call one of the DMA unmap routines -pci_unmap_{single,sg}. If you don't touch the data from the first pci_map_* -call till pci_unmap_*, then you don't have to call the pci_dma_sync_* +dma_unmap_{single,sg}. If you don't touch the data from the first dma_map_* +call till dma_unmap_*, then you don't have to call the dma_sync_* routines at all. Here is pseudo code which shows a situation in which you would need -to use the pci_dma_sync_*() interfaces. +to use the dma_sync_*() interfaces. my_card_setup_receive_buffer(struct my_card *cp, char *buffer, int len) { dma_addr_t mapping; - mapping = pci_map_single(cp->pdev, buffer, len, PCI_DMA_FROMDEVICE); + mapping = dma_map_single(cp->dev, buffer, len, DMA_FROM_DEVICE); cp->rx_buf = buffer; cp->rx_len = len; @@ -606,25 +601,25 @@ to use the pci_dma_sync_*() interfaces. * the DMA transfer with the CPU first * so that we see updated contents. */ - pci_dma_sync_single_for_cpu(cp->pdev, cp->rx_dma, - cp->rx_len, - PCI_DMA_FROMDEVICE); + dma_sync_single_for_cpu(&cp->dev, cp->rx_dma, + cp->rx_len, + DMA_FROM_DEVICE); /* Now it is safe to examine the buffer. */ hp = (struct my_card_header *) cp->rx_buf; if (header_is_ok(hp)) { - pci_unmap_single(cp->pdev, cp->rx_dma, cp->rx_len, - PCI_DMA_FROMDEVICE); + dma_unmap_single(&cp->dev, cp->rx_dma, cp->rx_len, + DMA_FROM_DEVICE); pass_to_upper_layers(cp->rx_buf); make_and_setup_new_rx_buf(cp); } else { /* Just sync the buffer and give it back * to the card. */ - pci_dma_sync_single_for_device(cp->pdev, - cp->rx_dma, - cp->rx_len, - PCI_DMA_FROMDEVICE); + dma_sync_single_for_device(&cp->dev, + cp->rx_dma, + cp->rx_len, + DMA_FROM_DEVICE); give_rx_buf_to_card(cp); } } @@ -634,19 +629,19 @@ Drivers converted fully to this interface should not use virt_to_bus any longer, nor should they use bus_to_virt. Some drivers have to be changed a little bit, because there is no longer an equivalent to bus_to_virt in the dynamic DMA mapping scheme - you have to always store the DMA addresses -returned by the pci_alloc_consistent, pci_pool_alloc, and pci_map_single -calls (pci_map_sg stores them in the scatterlist itself if the platform +returned by the dma_alloc_coherent, dma_pool_alloc, and dma_map_single +calls (dma_map_sg stores them in the scatterlist itself if the platform supports dynamic DMA mapping in hardware) in your driver structures and/or in the card registers. -All PCI drivers should be using these interfaces with no exceptions. -It is planned to completely remove virt_to_bus() and bus_to_virt() as +All drivers should be using these interfaces with no exceptions. It +is planned to completely remove virt_to_bus() and bus_to_virt() as they are entirely deprecated. Some ports already do not provide these as it is impossible to correctly support them. Optimizing Unmap State Space Consumption -On many platforms, pci_unmap_{single,page}() is simply a nop. +On many platforms, dma_unmap_{single,page}() is simply a nop. Therefore, keeping track of the mapping address and length is a waste of space. Instead of filling your drivers up with ifdefs and the like to "work around" this (which would defeat the whole purpose of a @@ -655,7 +650,7 @@ portable API) the following facilities are provided. Actually, instead of describing the macros one by one, we'll transform some example code. -1) Use DECLARE_PCI_UNMAP_{ADDR,LEN} in state saving structures. +1) Use DEFINE_DMA_UNMAP_{ADDR,LEN} in state saving structures. Example, before: struct ring_state { @@ -668,14 +663,11 @@ transform some example code. struct ring_state { struct sk_buff *skb; - DECLARE_PCI_UNMAP_ADDR(mapping) - DECLARE_PCI_UNMAP_LEN(len) + DEFINE_DMA_UNMAP_ADDR(mapping); + DEFINE_DMA_UNMAP_LEN(len); }; - NOTE: DO NOT put a semicolon at the end of the DECLARE_*() - macro. - -2) Use pci_unmap_{addr,len}_set to set these values. +2) Use dma_unmap_{addr,len}_set to set these values. Example, before: ringp->mapping = FOO; @@ -683,21 +675,21 @@ transform some example code. after: - pci_unmap_addr_set(ringp, mapping, FOO); - pci_unmap_len_set(ringp, len, BAR); + dma_unmap_addr_set(ringp, mapping, FOO); + dma_unmap_len_set(ringp, len, BAR); -3) Use pci_unmap_{addr,len} to access these values. +3) Use dma_unmap_{addr,len} to access these values. Example, before: - pci_unmap_single(pdev, ringp->mapping, ringp->len, - PCI_DMA_FROMDEVICE); + dma_unmap_single(dev, ringp->mapping, ringp->len, + DMA_FROM_DEVICE); after: - pci_unmap_single(pdev, - pci_unmap_addr(ringp, mapping), - pci_unmap_len(ringp, len), - PCI_DMA_FROMDEVICE); + dma_unmap_single(dev, + dma_unmap_addr(ringp, mapping), + dma_unmap_len(ringp, len), + DMA_FROM_DEVICE); It really should be self-explanatory. We treat the ADDR and LEN separately, because it is possible for an implementation to only @@ -732,15 +724,15 @@ to "Closing". DMA address space is limited on some architectures and an allocation failure can be determined by: -- checking if pci_alloc_consistent returns NULL or pci_map_sg returns 0 +- checking if dma_alloc_coherent returns NULL or dma_map_sg returns 0 -- checking the returned dma_addr_t of pci_map_single and pci_map_page - by using pci_dma_mapping_error(): +- checking the returned dma_addr_t of dma_map_single and dma_map_page + by using dma_mapping_error(): dma_addr_t dma_handle; - dma_handle = pci_map_single(pdev, addr, size, direction); - if (pci_dma_mapping_error(pdev, dma_handle)) { + dma_handle = dma_map_single(dev, addr, size, direction); + if (dma_mapping_error(dev, dma_handle)) { /* * reduce current DMA mapping usage, * delay and try again later or diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 5aceb88b3f8..05e2ae23686 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -4,20 +4,18 @@ James E.J. Bottomley <James.Bottomley@HansenPartnership.com> This document describes the DMA API. For a more gentle introduction -phrased in terms of the pci_ equivalents (and actual examples) see -Documentation/PCI/PCI-DMA-mapping.txt. +of the API (and actual examples) see +Documentation/DMA-API-HOWTO.txt. -This API is split into two pieces. Part I describes the API and the -corresponding pci_ API. Part II describes the extensions to the API -for supporting non-consistent memory machines. Unless you know that -your driver absolutely has to support non-consistent platforms (this -is usually only legacy platforms) you should only use the API -described in part I. +This API is split into two pieces. Part I describes the API. Part II +describes the extensions to the API for supporting non-consistent +memory machines. Unless you know that your driver absolutely has to +support non-consistent platforms (this is usually only legacy +platforms) you should only use the API described in part I. -Part I - pci_ and dma_ Equivalent API +Part I - dma_ API ------------------------------------- -To get the pci_ API, you must #include <linux/pci.h> To get the dma_ API, you must #include <linux/dma-mapping.h> @@ -27,9 +25,6 @@ Part Ia - Using large dma-coherent buffers void * dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag) -void * -pci_alloc_consistent(struct pci_dev *dev, size_t size, - dma_addr_t *dma_handle) Consistent memory is memory for which a write by either the device or the processor can immediately be read by the processor or device @@ -53,15 +48,11 @@ The simplest way to do that is to use the dma_pool calls (see below). The flag parameter (dma_alloc_coherent only) allows the caller to specify the GFP_ flags (see kmalloc) for the allocation (the implementation may choose to ignore flags that affect the location of -the returned memory, like GFP_DMA). For pci_alloc_consistent, you -must assume GFP_ATOMIC behaviour. +the returned memory, like GFP_DMA). void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_handle) -void -pci_free_consistent(struct pci_dev *dev, size_t size, void *cpu_addr, - dma_addr_t dma_handle) Free the region of consistent memory you previously allocated. dev, size and dma_handle must all be the same as those passed into the @@ -89,10 +80,6 @@ for alignment, like queue heads needing to be aligned on N-byte boundaries. dma_pool_create(const char *name, struct device *dev, size_t size, size_t align, size_t alloc); - struct pci_pool * - pci_pool_create(const char *name, struct pci_device *dev, - size_t size, size_t align, size_t alloc); - The pool create() routines initialize a pool of dma-coherent buffers for use with a given device. It must be called in a context which can sleep. @@ -108,9 +95,6 @@ from this pool must not cross 4KByte boundaries. void *dma_pool_alloc(struct dma_pool *pool, gfp_t gfp_flags, dma_addr_t *dma_handle); - void *pci_pool_alloc(struct pci_pool *pool, gfp_t gfp_flags, - dma_addr_t *dma_handle); - This allocates memory from the pool; the returned memory will meet the size and alignment requirements specified at creation time. Pass GFP_ATOMIC to prevent blocking, or if it's permitted (not in_interrupt, not holding SMP locks), @@ -122,9 +106,6 @@ pool's device. void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t addr); - void pci_pool_free(struct pci_pool *pool, void *vaddr, - dma_addr_t addr); - This puts memory back into the pool. The pool is what was passed to the pool allocation routine; the cpu (vaddr) and dma addresses are what were returned when that routine allocated the memory being freed. @@ -132,8 +113,6 @@ were returned when that routine allocated the memory being freed. void dma_pool_destroy(struct dma_pool *pool); - void pci_pool_destroy(struct pci_pool *pool); - The pool destroy() routines free the resources of the pool. They must be called in a context which can sleep. Make sure you've freed all allocated memory back to the pool before you destroy it. @@ -144,8 +123,6 @@ Part Ic - DMA addressing limitations int dma_supported(struct device *dev, u64 mask) -int -pci_dma_supported(struct pci_dev *hwdev, u64 mask) Checks to see if the device can support DMA to the memory described by mask. @@ -159,8 +136,14 @@ driver writers. int dma_set_mask(struct device *dev, u64 mask) + +Checks to see if the mask is possible and updates the device +parameters if it is. + +Returns: 0 if successful and a negative error if not. + int -pci_set_dma_mask(struct pci_device *dev, u64 mask) +dma_set_coherent_mask(struct device *dev, u64 mask) Checks to see if the mask is possible and updates the device parameters if it is. @@ -187,9 +170,6 @@ Part Id - Streaming DMA mappings dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, size_t size, enum dma_data_direction direction) -dma_addr_t -pci_map_single(struct pci_dev *hwdev, void *cpu_addr, size_t size, - int direction) Maps a piece of processor virtual memory so it can be accessed by the device and returns the physical handle of the memory. @@ -198,14 +178,10 @@ The direction for both api's may be converted freely by casting. However the dma_ API uses a strongly typed enumerator for its direction: -DMA_NONE = PCI_DMA_NONE no direction (used for - debugging) -DMA_TO_DEVICE = PCI_DMA_TODEVICE data is going from the - memory to the device -DMA_FROM_DEVICE = PCI_DMA_FROMDEVICE data is coming from - the device to the - memory -DMA_BIDIRECTIONAL = PCI_DMA_BIDIRECTIONAL direction isn't known +DMA_NONE no direction (used for debugging) +DMA_TO_DEVICE data is going from the memory to the device +DMA_FROM_DEVICE data is coming from the device to the memory +DMA_BIDIRECTIONAL direction isn't known Notes: Not all memory regions in a machine can be mapped by this API. Further, regions that appear to be physically contiguous in @@ -268,9 +244,6 @@ cache lines are updated with data that the device may have changed). void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size, enum dma_data_direction direction) -void -pci_unmap_single(struct pci_dev *hwdev, dma_addr_t dma_addr, - size_t size, int direction) Unmaps the region previously mapped. All the parameters passed in must be identical to those passed in (and returned) by the mapping @@ -280,15 +253,9 @@ dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction direction) -dma_addr_t -pci_map_page(struct pci_dev *hwdev, struct page *page, - unsigned long offset, size_t size, int direction) void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size, enum dma_data_direction direction) -void -pci_unmap_page(struct pci_dev *hwdev, dma_addr_t dma_address, - size_t size, int direction) API for mapping and unmapping for pages. All the notes and warnings for the other mapping APIs apply here. Also, although the <offset> @@ -299,9 +266,6 @@ cache width is. int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) -int -pci_dma_mapping_error(struct pci_dev *hwdev, dma_addr_t dma_addr) - In some circumstances dma_map_single and dma_map_page will fail to create a mapping. A driver can check for these errors by testing the returned dma address with dma_mapping_error(). A non-zero return value means the mapping @@ -311,9 +275,6 @@ reduce current DMA mapping usage or delay and try again later). int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction direction) - int - pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg, - int nents, int direction) Returns: the number of physical segments mapped (this may be shorter than <nents> passed in if some elements of the scatter/gather list are @@ -353,9 +314,6 @@ accessed sg->address and sg->length as shown above. void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries, enum dma_data_direction direction) - void - pci_unmap_sg(struct pci_dev *hwdev, struct scatterlist *sg, - int nents, int direction) Unmap the previously mapped scatter/gather list. All the parameters must be the same as those and passed in to the scatter/gather mapping @@ -365,21 +323,23 @@ Note: <nents> must be the number you passed in, *not* the number of physical entries returned. void -dma_sync_single(struct device *dev, dma_addr_t dma_handle, size_t size, - enum dma_data_direction direction) +dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, + enum dma_data_direction direction) void -pci_dma_sync_single(struct pci_dev *hwdev, dma_addr_t dma_handle, - size_t size, int direction) +dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size, + enum dma_data_direction direction) void -dma_sync_sg(struct device *dev, struct scatterlist *sg, int nelems, - enum dma_data_direction direction) +dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems, + enum dma_data_direction direction) void -pci_dma_sync_sg(struct pci_dev *hwdev, struct scatterlist *sg, - int nelems, int direction) +dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, + enum dma_data_direction direction) -Synchronise a single contiguous or scatter/gather mapping. All the -parameters must be the same as those passed into the single mapping -API. +Synchronise a single contiguous or scatter/gather mapping for the cpu +and device. With the sync_sg API, all the parameters must be the same +as those passed into the single mapping API. With the sync_single API, +you can use dma_handle and size parameters that aren't identical to +those passed into the single mapping API to do a partial sync. Notes: You must do this: @@ -461,9 +421,9 @@ void whizco_dma_map_sg_attrs(struct device *dev, dma_addr_t dma_addr, Part II - Advanced dma_ usage ----------------------------- -Warning: These pieces of the DMA API have no PCI equivalent. They -should also not be used in the majority of cases, since they cater for -unlikely corner cases that don't belong in usual drivers. +Warning: These pieces of the DMA API should not be used in the +majority of cases, since they cater for unlikely corner cases that +don't belong in usual drivers. If you don't understand how cache line coherency works between a processor and an I/O device, you should not be using this part of the @@ -514,16 +474,6 @@ into the width returned by this call. It will also always be a power of two for easy alignment. void -dma_sync_single_range(struct device *dev, dma_addr_t dma_handle, - unsigned long offset, size_t size, - enum dma_data_direction direction) - -Does a partial sync, starting at offset and continuing for size. You -must be careful to observe the cache alignment and width when doing -anything like this. You must also be extra careful about accessing -memory you intend to sync partially. - -void dma_cache_sync(struct device *dev, void *vaddr, size_t size, enum dma_data_direction direction) diff --git a/Documentation/DocBook/mtdnand.tmpl b/Documentation/DocBook/mtdnand.tmpl index 5e7d84b4850..133cd6c3f3c 100644 --- a/Documentation/DocBook/mtdnand.tmpl +++ b/Documentation/DocBook/mtdnand.tmpl @@ -488,7 +488,7 @@ static void board_select_chip (struct mtd_info *mtd, int chip) The ECC bytes must be placed immidiately after the data bytes in order to make the syndrome generator work. This is contrary to the usual layout used by software ECC. The - seperation of data and out of band area is not longer + separation of data and out of band area is not longer possible. The nand driver code handles this layout and the remaining free bytes in the oob area are managed by the autoplacement code. Provide a matching oob-layout @@ -560,7 +560,7 @@ static void board_select_chip (struct mtd_info *mtd, int chip) bad blocks. They have factory marked good blocks. The marker pattern is erased when the block is erased to be reused. So in case of powerloss before writing the pattern back to the chip this block - would be lost and added to the bad blocks. Therefor we scan the + would be lost and added to the bad blocks. Therefore we scan the chip(s) when we detect them the first time for good blocks and store this information in a bad block table before erasing any of the blocks. @@ -1094,7 +1094,7 @@ in this page</entry> manufacturers specifications. This applies similar to the spare area. </para> <para> - Therefor NAND aware filesystems must either write in page size chunks + Therefore NAND aware filesystems must either write in page size chunks or hold a writebuffer to collect smaller writes until they sum up to pagesize. Available NAND aware filesystems: JFFS2, YAFFS. </para> diff --git a/Documentation/DocBook/tracepoint.tmpl b/Documentation/DocBook/tracepoint.tmpl index 8bca1d5cec0..e8473eae2a2 100644 --- a/Documentation/DocBook/tracepoint.tmpl +++ b/Documentation/DocBook/tracepoint.tmpl @@ -16,6 +16,15 @@ </address> </affiliation> </author> + <author> + <firstname>William</firstname> + <surname>Cohen</surname> + <affiliation> + <address> + <email>wcohen@redhat.com</email> + </address> + </affiliation> + </author> </authorgroup> <legalnotice> @@ -91,4 +100,8 @@ !Iinclude/trace/events/signal.h </chapter> + <chapter id="block"> + <title>Block IO</title> +!Iinclude/trace/events/block.h + </chapter> </book> diff --git a/Documentation/DocBook/v4l/common.xml b/Documentation/DocBook/v4l/common.xml index c65f0ac9b6e..cea23e1c4fc 100644 --- a/Documentation/DocBook/v4l/common.xml +++ b/Documentation/DocBook/v4l/common.xml @@ -1170,7 +1170,7 @@ frames per second. If less than this number of frames is to be captured or output, applications can request frame skipping or duplicating on the driver side. This is especially useful when using the &func-read; or &func-write;, which are not augmented by timestamps -or sequence counters, and to avoid unneccessary data copying.</para> +or sequence counters, and to avoid unnecessary data copying.</para> <para>Finally these ioctls can be used to determine the number of buffers used internally by a driver in read/write mode. For diff --git a/Documentation/DocBook/v4l/vidioc-g-parm.xml b/Documentation/DocBook/v4l/vidioc-g-parm.xml index 78332d365ce..392aa9e5571 100644 --- a/Documentation/DocBook/v4l/vidioc-g-parm.xml +++ b/Documentation/DocBook/v4l/vidioc-g-parm.xml @@ -55,7 +55,7 @@ captured or output, applications can request frame skipping or duplicating on the driver side. This is especially useful when using the <function>read()</function> or <function>write()</function>, which are not augmented by timestamps or sequence counters, and to avoid -unneccessary data copying.</para> +unnecessary data copying.</para> <para>Further these ioctls can be used to determine the number of buffers used internally by a driver in read/write mode. For diff --git a/Documentation/HOWTO b/Documentation/HOWTO index f5395af88a4..40ada93b820 100644 --- a/Documentation/HOWTO +++ b/Documentation/HOWTO @@ -234,7 +234,7 @@ process is as follows: Linus, usually the patches that have already been included in the -next kernel for a few weeks. The preferred way to submit big changes is using git (the kernel's source management tool, more information - can be found at http://git.or.cz/) but plain patches are also just + can be found at http://git-scm.com/) but plain patches are also just fine. - After two weeks a -rc1 kernel is released it is now possible to push only patches that do not include new features that could affect the diff --git a/Documentation/IPMI.txt b/Documentation/IPMI.txt index bc38283379f..69dd29ed824 100644 --- a/Documentation/IPMI.txt +++ b/Documentation/IPMI.txt @@ -365,6 +365,7 @@ You can change this at module load time (for a module) with: regshifts=<shift1>,<shift2>,... slave_addrs=<addr1>,<addr2>,... force_kipmid=<enable1>,<enable2>,... + kipmid_max_busy_us=<ustime1>,<ustime2>,... unload_when_empty=[0|1] Each of these except si_trydefaults is a list, the first item for the @@ -433,6 +434,7 @@ kernel command line as: ipmi_si.regshifts=<shift1>,<shift2>,... ipmi_si.slave_addrs=<addr1>,<addr2>,... ipmi_si.force_kipmid=<enable1>,<enable2>,... + ipmi_si.kipmid_max_busy_us=<ustime1>,<ustime2>,... It works the same as the module parameters of the same names. @@ -450,6 +452,16 @@ force this thread on or off. If you force it off and don't have interrupts, the driver will run VERY slowly. Don't blame me, these interfaces suck. +Unfortunately, this thread can use a lot of CPU depending on the +interface's performance. This can waste a lot of CPU and cause +various issues with detecting idle CPU and using extra power. To +avoid this, the kipmid_max_busy_us sets the maximum amount of time, in +microseconds, that kipmid will spin before sleeping for a tick. This +value sets a balance between performance and CPU waste and needs to be +tuned to your needs. Maybe, someday, auto-tuning will be added, but +that's not a simple thing and even the auto-tuning would need to be +tuned to the user's desired performance. + The driver supports a hot add and remove of interfaces. This way, interfaces can be added or removed after the kernel is up and running. This is done using /sys/modules/ipmi_si/parameters/hotmod, which is a diff --git a/Documentation/Makefile b/Documentation/Makefile index 94b94573353..6fc7ea1d1f9 100644 --- a/Documentation/Makefile +++ b/Documentation/Makefile @@ -1,3 +1,3 @@ obj-m := DocBook/ accounting/ auxdisplay/ connector/ \ - filesystems/configfs/ ia64/ networking/ \ - pcmcia/ spi/ video4linux/ vm/ watchdog/src/ + filesystems/ filesystems/configfs/ ia64/ laptops/ networking/ \ + pcmcia/ spi/ timers/ video4linux/ vm/ watchdog/src/ diff --git a/Documentation/RCU/NMI-RCU.txt b/Documentation/RCU/NMI-RCU.txt index a6d32e65d22..a8536cb8809 100644 --- a/Documentation/RCU/NMI-RCU.txt +++ b/Documentation/RCU/NMI-RCU.txt @@ -34,7 +34,7 @@ NMI handler. cpu = smp_processor_id(); ++nmi_count(cpu); - if (!rcu_dereference(nmi_callback)(regs, cpu)) + if (!rcu_dereference_sched(nmi_callback)(regs, cpu)) default_do_nmi(regs); nmi_exit(); @@ -47,12 +47,13 @@ function pointer. If this handler returns zero, do_nmi() invokes the default_do_nmi() function to handle a machine-specific NMI. Finally, preemption is restored. -Strictly speaking, rcu_dereference() is not needed, since this code runs -only on i386, which does not need rcu_dereference() anyway. However, -it is a good documentation aid, particularly for anyone attempting to -do something similar on Alpha. +In theory, rcu_dereference_sched() is not needed, since this code runs +only on i386, which in theory does not need rcu_dereference_sched() +anyway. However, in practice it is a good documentation aid, particularly +for anyone attempting to do something similar on Alpha or on systems +with aggressive optimizing compilers. -Quick Quiz: Why might the rcu_dereference() be necessary on Alpha, +Quick Quiz: Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only? @@ -99,17 +100,21 @@ invoke irq_enter() and irq_exit() on NMI entry and exit, respectively. Answer to Quick Quiz - Why might the rcu_dereference() be necessary on Alpha, given + Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only? Answer: The caller to set_nmi_callback() might well have - initialized some data that is to be used by the - new NMI handler. In this case, the rcu_dereference() - would be needed, because otherwise a CPU that received - an NMI just after the new handler was set might see - the pointer to the new NMI handler, but the old - pre-initialized version of the handler's data. - - More important, the rcu_dereference() makes it clear - to someone reading the code that the pointer is being - protected by RCU. + initialized some data that is to be used by the new NMI + handler. In this case, the rcu_dereference_sched() would + be needed, because otherwise a CPU that received an NMI + just after the new handler was set might see the pointer + to the new NMI handler, but the old pre-initialized + version of the handler's data. + + This same sad story can happen on other CPUs when using + a compiler with aggressive pointer-value speculation + optimizations. + + More important, the rcu_dereference_sched() makes it + clear to someone reading the code that the pointer is + being protected by RCU-sched. diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt index cbc180f9019..790d1a81237 100644 --- a/Documentation/RCU/checklist.txt +++ b/Documentation/RCU/checklist.txt @@ -260,7 +260,8 @@ over a rather long period of time, but improvements are always welcome! The reason that it is permissible to use RCU list-traversal primitives when the update-side lock is held is that doing so can be quite helpful in reducing code bloat when common code is - shared between readers and updaters. + shared between readers and updaters. Additional primitives + are provided for this case, as discussed in lockdep.txt. 10. Conversely, if you are in an RCU read-side critical section, and you don't hold the appropriate update-side lock, you -must- @@ -344,8 +345,8 @@ over a rather long period of time, but improvements are always welcome! requiring SRCU's read-side deadlock immunity or low read-side realtime latency. - Note that, rcu_assign_pointer() and rcu_dereference() relate to - SRCU just as they do to other forms of RCU. + Note that, rcu_assign_pointer() relates to SRCU just as they do + to other forms of RCU. 15. The whole point of call_rcu(), synchronize_rcu(), and friends is to wait until all pre-existing readers have finished before diff --git a/Documentation/RCU/lockdep.txt b/Documentation/RCU/lockdep.txt index fe24b58627b..d7a49b2f699 100644 --- a/Documentation/RCU/lockdep.txt +++ b/Documentation/RCU/lockdep.txt @@ -32,9 +32,20 @@ checking of rcu_dereference() primitives: srcu_dereference(p, sp): Check for SRCU read-side critical section. rcu_dereference_check(p, c): - Use explicit check expression "c". + Use explicit check expression "c". This is useful in + code that is invoked by both readers and updaters. rcu_dereference_raw(p) Don't check. (Use sparingly, if at all.) + rcu_dereference_protected(p, c): + Use explicit check expression "c", and omit all barriers + and compiler constraints. This is useful when the data + structure cannot change, for example, in code that is + invoked only by updaters. + rcu_access_pointer(p): + Return the value of the pointer and omit all barriers, + but retain the compiler constraints that prevent duplicating + or coalescsing. This is useful when when testing the + value of the pointer itself, for example, against NULL. The rcu_dereference_check() check expression can be any boolean expression, but would normally include one of the rcu_read_lock_held() @@ -59,7 +70,20 @@ In case (1), the pointer is picked up in an RCU-safe manner for vanilla RCU read-side critical sections, in case (2) the ->file_lock prevents any change from taking place, and finally, in case (3) the current task is the only task accessing the file_struct, again preventing any change -from taking place. +from taking place. If the above statement was invoked only from updater +code, it could instead be written as follows: + + file = rcu_dereference_protected(fdt->fd[fd], + lockdep_is_held(&files->file_lock) || + atomic_read(&files->count) == 1); + +This would verify cases #2 and #3 above, and furthermore lockdep would +complain if this was used in an RCU read-side critical section unless one +of these two cases held. Because rcu_dereference_protected() omits all +barriers and compiler constraints, it generates better code than do the +other flavors of rcu_dereference(). On the other hand, it is illegal +to use rcu_dereference_protected() if either the RCU-protected pointer +or the RCU-protected data that it points to can change concurrently. There are currently only "universal" versions of the rcu_assign_pointer() and RCU list-/tree-traversal primitives, which do not (yet) check for diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 1dc00ee9716..cfaac34c455 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -840,6 +840,12 @@ SRCU: Initialization/cleanup init_srcu_struct cleanup_srcu_struct +All: lockdep-checked RCU-protected pointer access + + rcu_dereference_check + rcu_dereference_protected + rcu_access_pointer + See the comment headers in the source code (or the docbook generated from them) for more information. diff --git a/Documentation/SubmitChecklist b/Documentation/SubmitChecklist index 1053a56be3b..8916ca48bc9 100644 --- a/Documentation/SubmitChecklist +++ b/Documentation/SubmitChecklist @@ -9,10 +9,14 @@ Documentation/SubmittingPatches and elsewhere regarding submitting Linux kernel patches. -1: Builds cleanly with applicable or modified CONFIG options =y, =m, and +1: If you use a facility then #include the file that defines/declares + that facility. Don't depend on other header files pulling in ones + that you use. + +2: Builds cleanly with applicable or modified CONFIG options =y, =m, and =n. No gcc warnings/errors, no linker warnings/errors. -2: Passes allnoconfig, allmodconfig +2b: Passes allnoconfig, allmodconfig 3: Builds on multiple CPU architectures by using local cross-compile tools or some other build farm. diff --git a/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt b/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt index 76b3a11e90b..fa968aa99d6 100644 --- a/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt +++ b/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt @@ -14,8 +14,8 @@ Introduction how the clocks are arranged. The first implementation used as single PLL to feed the ARM, memory and peripherals via a series of dividers and muxes and this is the implementation that is documented here. A - newer version where there is a seperate PLL and clock divider for the - ARM core is available as a seperate driver. + newer version where there is a separate PLL and clock divider for the + ARM core is available as a separate driver. Layout diff --git a/Documentation/arm/Samsung/Overview.txt b/Documentation/arm/Samsung/Overview.txt new file mode 100644 index 00000000000..7cced1fea9c --- /dev/null +++ b/Documentation/arm/Samsung/Overview.txt @@ -0,0 +1,86 @@ + Samsung ARM Linux Overview + ========================== + +Introduction +------------ + + The Samsung range of ARM SoCs spans many similar devices, from the initial + ARM9 through to the newest ARM cores. This document shows an overview of + the current kernel support, how to use it and where to find the code + that supports this. + + The currently supported SoCs are: + + - S3C24XX: See Documentation/arm/Samsung-S3C24XX/Overview.txt for full list + - S3C64XX: S3C6400 and S3C6410 + - S5PC6440 + + S5PC100 and S5PC110 support is currently being merged + + +S3C24XX Systems +--------------- + + There is still documentation in Documnetation/arm/Samsung-S3C24XX/ which + deals with the architecture and drivers specific to these devices. + + See Documentation/arm/Samsung-S3C24XX/Overview.txt for more information + on the implementation details and specific support. + + +Configuration +------------- + + A number of configurations are supplied, as there is no current way of + unifying all the SoCs into one kernel. + + s5p6440_defconfig - S5P6440 specific default configuration + s5pc100_defconfig - S5PC100 specific default configuration + + +Layout +------ + + The directory layout is currently being restructured, and consists of + several platform directories and then the machine specific directories + of the CPUs being built for. + + plat-samsung provides the base for all the implementations, and is the + last in the line of include directories that are processed for the build + specific information. It contains the base clock, GPIO and device definitions + to get the system running. + + plat-s3c is the s3c24xx/s3c64xx platform directory, although it is currently + involved in other builds this will be phased out once the relevant code is + moved elsewhere. + + plat-s3c24xx is for s3c24xx specific builds, see the S3C24XX docs. + + plat-s3c64xx is for the s3c64xx specific bits, see the S3C24XX docs. + + plat-s5p is for s5p specific builds, more to be added. + + + [ to finish ] + + +Port Contributors +----------------- + + Ben Dooks (BJD) + Vincent Sanders + Herbert Potzl + Arnaud Patard (RTP) + Roc Wu + Klaus Fetscher + Dimitry Andric + Shannon Holland + Guillaume Gourat (NexVision) + Christer Weinigel (wingel) (Acer N30) + Lucas Correia Villa Real (S3C2400 port) + + +Document Author +--------------- + +Copyright 2009-2010 Ben Dooks <ben-linux@fluff.org> diff --git a/Documentation/arm/Samsung/clksrc-change-registers.awk b/Documentation/arm/Samsung/clksrc-change-registers.awk new file mode 100755 index 00000000000..0c50220851f --- /dev/null +++ b/Documentation/arm/Samsung/clksrc-change-registers.awk @@ -0,0 +1,167 @@ +#!/usr/bin/awk -f +# +# Copyright 2010 Ben Dooks <ben-linux@fluff.org> +# +# Released under GPLv2 + +# example usage +# ./clksrc-change-registers.awk arch/arm/plat-s5pc1xx/include/plat/regs-clock.h < src > dst + +function extract_value(s) +{ + eqat = index(s, "=") + comat = index(s, ",") + return substr(s, eqat+2, (comat-eqat)-2) +} + +function remove_brackets(b) +{ + return substr(b, 2, length(b)-2) +} + +function splitdefine(l, p) +{ + r = split(l, tp) + + p[0] = tp[2] + p[1] = remove_brackets(tp[3]) +} + +function find_length(f) +{ + if (0) + printf "find_length " f "\n" > "/dev/stderr" + + if (f ~ /0x1/) + return 1 + else if (f ~ /0x3/) + return 2 + else if (f ~ /0x7/) + return 3 + else if (f ~ /0xf/) + return 4 + + printf "unknown legnth " f "\n" > "/dev/stderr" + exit +} + +function find_shift(s) +{ + id = index(s, "<") + if (id <= 0) { + printf "cannot find shift " s "\n" > "/dev/stderr" + exit + } + + return substr(s, id+2) +} + + +BEGIN { + if (ARGC < 2) { + print "too few arguments" > "/dev/stderr" + exit + } + +# read the header file and find the mask values that we will need +# to replace and create an associative array of values + + while (getline line < ARGV[1] > 0) { + if (line ~ /\#define.*_MASK/ && + !(line ~ /S5PC100_EPLL_MASK/) && + !(line ~ /USB_SIG_MASK/)) { + splitdefine(line, fields) + name = fields[0] + if (0) + printf "MASK " line "\n" > "/dev/stderr" + dmask[name,0] = find_length(fields[1]) + dmask[name,1] = find_shift(fields[1]) + if (0) + printf "=> '" name "' LENGTH=" dmask[name,0] " SHIFT=" dmask[name,1] "\n" > "/dev/stderr" + } else { + } + } + + delete ARGV[1] +} + +/clksrc_clk.*=.*{/ { + shift="" + mask="" + divshift="" + reg_div="" + reg_src="" + indent=1 + + print $0 + + for(; indent >= 1;) { + if ((getline line) <= 0) { + printf "unexpected end of file" > "/dev/stderr" + exit 1; + } + + if (line ~ /\.shift/) { + shift = extract_value(line) + } else if (line ~ /\.mask/) { + mask = extract_value(line) + } else if (line ~ /\.reg_divider/) { + reg_div = extract_value(line) + } else if (line ~ /\.reg_source/) { + reg_src = extract_value(line) + } else if (line ~ /\.divider_shift/) { + divshift = extract_value(line) + } else if (line ~ /{/) { + indent++ + print line + } else if (line ~ /}/) { + indent-- + + if (indent == 0) { + if (0) { + printf "shift '" shift "' ='" dmask[shift,0] "'\n" > "/dev/stderr" + printf "mask '" mask "'\n" > "/dev/stderr" + printf "dshft '" divshift "'\n" > "/dev/stderr" + printf "rdiv '" reg_div "'\n" > "/dev/stderr" + printf "rsrc '" reg_src "'\n" > "/dev/stderr" + } + + generated = mask + sub(reg_src, reg_div, generated) + + if (0) { + printf "/* rsrc " reg_src " */\n" + printf "/* rdiv " reg_div " */\n" + printf "/* shift " shift " */\n" + printf "/* mask " mask " */\n" + printf "/* generated " generated " */\n" + } + + if (reg_div != "") { + printf "\t.reg_div = { " + printf ".reg = " reg_div ", " + printf ".shift = " dmask[generated,1] ", " + printf ".size = " dmask[generated,0] ", " + printf "},\n" + } + + printf "\t.reg_src = { " + printf ".reg = " reg_src ", " + printf ".shift = " dmask[mask,1] ", " + printf ".size = " dmask[mask,0] ", " + + printf "},\n" + + } + + print line + } else { + print line + } + + if (0) + printf indent ":" line "\n" > "/dev/stderr" + } +} + +// && ! /clksrc_clk.*=.*{/ { print $0 } diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 6fab97ea7e6..508b5b2b028 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -1162,8 +1162,8 @@ where a driver received a request ala this before: As mentioned, there is no virtual mapping of a bio. For DMA, this is not a problem as the driver probably never will need a virtual mapping. -Instead it needs a bus mapping (pci_map_page for a single segment or -use blk_rq_map_sg for scatter gather) to be able to ship it to the driver. For +Instead it needs a bus mapping (dma_map_page for a single segment or +use dma_map_sg for scatter gather) to be able to ship it to the driver. For PIO drivers (or drivers that need to revert to PIO transfer once in a while (IDE for example)), where the CPU is doing the actual data transfer a virtual mapping is needed. If the driver supports highmem I/O, diff --git a/Documentation/cgroups/cgroup_event_listener.c b/Documentation/cgroups/cgroup_event_listener.c new file mode 100644 index 00000000000..8c2bfc4a635 --- /dev/null +++ b/Documentation/cgroups/cgroup_event_listener.c @@ -0,0 +1,110 @@ +/* + * cgroup_event_listener.c - Simple listener of cgroup events + * + * Copyright (C) Kirill A. Shutemov <kirill@shutemov.name> + */ + +#include <assert.h> +#include <errno.h> +#include <fcntl.h> +#include <libgen.h> +#include <limits.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> + +#include <sys/eventfd.h> + +#define USAGE_STR "Usage: cgroup_event_listener <path-to-control-file> <args>\n" + +int main(int argc, char **argv) +{ + int efd = -1; + int cfd = -1; + int event_control = -1; + char event_control_path[PATH_MAX]; + char line[LINE_MAX]; + int ret; + + if (argc != 3) { + fputs(USAGE_STR, stderr); + return 1; + } + + cfd = open(argv[1], O_RDONLY); + if (cfd == -1) { + fprintf(stderr, "Cannot open %s: %s\n", argv[1], + strerror(errno)); + goto out; + } + + ret = snprintf(event_control_path, PATH_MAX, "%s/cgroup.event_control", + dirname(argv[1])); + if (ret >= PATH_MAX) { + fputs("Path to cgroup.event_control is too long\n", stderr); + goto out; + } + + event_control = open(event_control_path, O_WRONLY); + if (event_control == -1) { + fprintf(stderr, "Cannot open %s: %s\n", event_control_path, + strerror(errno)); + goto out; + } + + efd = eventfd(0, 0); + if (efd == -1) { + perror("eventfd() failed"); + goto out; + } + + ret = snprintf(line, LINE_MAX, "%d %d %s", efd, cfd, argv[2]); + if (ret >= LINE_MAX) { + fputs("Arguments string is too long\n", stderr); + goto out; + } + + ret = write(event_control, line, strlen(line) + 1); + if (ret == -1) { + perror("Cannot write to cgroup.event_control"); + goto out; + } + + while (1) { + uint64_t result; + + ret = read(efd, &result, sizeof(result)); + if (ret == -1) { + if (errno == EINTR) + continue; + perror("Cannot read from eventfd"); + break; + } + assert(ret == sizeof(result)); + + ret = access(event_control_path, W_OK); + if ((ret == -1) && (errno == ENOENT)) { + puts("The cgroup seems to have removed."); + ret = 0; + break; + } + + if (ret == -1) { + perror("cgroup.event_control " + "is not accessable any more"); + break; + } + + printf("%s %s: crossed\n", argv[1], argv[2]); + } + +out: + if (efd >= 0) + close(efd); + if (event_control >= 0) + close(event_control); + if (cfd >= 0) + close(cfd); + + return (ret != 0); +} diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 0b33bfe7dde..a1ca5924faf 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -22,6 +22,8 @@ CONTENTS: 2. Usage Examples and Syntax 2.1 Basic Usage 2.2 Attaching processes + 2.3 Mounting hierarchies by name + 2.4 Notification API 3. Kernel API 3.1 Overview 3.2 Synchronization @@ -233,8 +235,7 @@ containing the following files describing that cgroup: - cgroup.procs: list of tgids in the cgroup. This list is not guaranteed to be sorted or free of duplicate tgids, and userspace should sort/uniquify the list if this property is required. - Writing a tgid into this file moves all threads with that tgid into - this cgroup. + This is a read-only file, for now. - notify_on_release flag: run the release agent on exit? - release_agent: the path to use for release notifications (this file exists in the top cgroup only) @@ -434,6 +435,25 @@ you give a subsystem a name. The name of the subsystem appears as part of the hierarchy description in /proc/mounts and /proc/<pid>/cgroups. +2.4 Notification API +-------------------- + +There is mechanism which allows to get notifications about changing +status of a cgroup. + +To register new notification handler you need: + - create a file descriptor for event notification using eventfd(2); + - open a control file to be monitored (e.g. memory.usage_in_bytes); + - write "<event_fd> <control_fd> <args>" to cgroup.event_control. + Interpretation of args is defined by control file implementation; + +eventfd will be woken up by control file implementation or when the +cgroup is removed. + +To unregister notification handler just close eventfd. + +NOTE: Support of notifications should be implemented for the control +file. See documentation for the subsystem. 3. Kernel API ============= @@ -488,6 +508,11 @@ Each subsystem should: - add an entry in linux/cgroup_subsys.h - define a cgroup_subsys object called <name>_subsys +If a subsystem can be compiled as a module, it should also have in its +module initcall a call to cgroup_load_subsys(), and in its exitcall a +call to cgroup_unload_subsys(). It should also set its_subsys.module = +THIS_MODULE in its .c file. + Each subsystem may export the following methods. The only mandatory methods are create/destroy. Any others that are null are presumed to be successful no-ops. @@ -536,10 +561,21 @@ returns an error, this will abort the attach operation. If a NULL task is passed, then a successful result indicates that *any* unspecified task can be moved into the cgroup. Note that this isn't called on a fork. If this method returns 0 (success) then this should -remain valid while the caller holds cgroup_mutex. If threadgroup is +remain valid while the caller holds cgroup_mutex and it is ensured that either +attach() or cancel_attach() will be called in future. If threadgroup is true, then a successful result indicates that all threads in the given thread's threadgroup can be moved together. +void cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, + struct task_struct *task, bool threadgroup) +(cgroup_mutex held by caller) + +Called when a task attach operation has failed after can_attach() has succeeded. +A subsystem whose can_attach() has some side-effects should provide this +function, so that the subsytem can implement a rollback. If not, not necessary. +This will be called only about subsystems whose can_attach() operation have +succeeded. + void attach(struct cgroup_subsys *ss, struct cgroup *cgrp, struct cgroup *old_cgrp, struct task_struct *task, bool threadgroup) diff --git a/Documentation/cgroups/cpusets.txt b/Documentation/cgroups/cpusets.txt index 1d7e9784439..4160df82b3f 100644 --- a/Documentation/cgroups/cpusets.txt +++ b/Documentation/cgroups/cpusets.txt @@ -168,20 +168,20 @@ Each cpuset is represented by a directory in the cgroup file system containing (on top of the standard cgroup files) the following files describing that cpuset: - - cpus: list of CPUs in that cpuset - - mems: list of Memory Nodes in that cpuset - - memory_migrate flag: if set, move pages to cpusets nodes - - cpu_exclusive flag: is cpu placement exclusive? - - mem_exclusive flag: is memory placement exclusive? - - mem_hardwall flag: is memory allocation hardwalled - - memory_pressure: measure of how much paging pressure in cpuset - - memory_spread_page flag: if set, spread page cache evenly on allowed nodes - - memory_spread_slab flag: if set, spread slab cache evenly on allowed nodes - - sched_load_balance flag: if set, load balance within CPUs on that cpuset - - sched_relax_domain_level: the searching range when migrating tasks + - cpuset.cpus: list of CPUs in that cpuset + - cpuset.mems: list of Memory Nodes in that cpuset + - cpuset.memory_migrate flag: if set, move pages to cpusets nodes + - cpuset.cpu_exclusive flag: is cpu placement exclusive? + - cpuset.mem_exclusive flag: is memory placement exclusive? + - cpuset.mem_hardwall flag: is memory allocation hardwalled + - cpuset.memory_pressure: measure of how much paging pressure in cpuset + - cpuset.memory_spread_page flag: if set, spread page cache evenly on allowed nodes + - cpuset.memory_spread_slab flag: if set, spread slab cache evenly on allowed nodes + - cpuset.sched_load_balance flag: if set, load balance within CPUs on that cpuset + - cpuset.sched_relax_domain_level: the searching range when migrating tasks In addition, the root cpuset only has the following file: - - memory_pressure_enabled flag: compute memory_pressure? + - cpuset.memory_pressure_enabled flag: compute memory_pressure? New cpusets are created using the mkdir system call or shell command. The properties of a cpuset, such as its flags, allowed @@ -229,7 +229,7 @@ If a cpuset is cpu or mem exclusive, no other cpuset, other than a direct ancestor or descendant, may share any of the same CPUs or Memory Nodes. -A cpuset that is mem_exclusive *or* mem_hardwall is "hardwalled", +A cpuset that is cpuset.mem_exclusive *or* cpuset.mem_hardwall is "hardwalled", i.e. it restricts kernel allocations for page, buffer and other data commonly shared by the kernel across multiple users. All cpusets, whether hardwalled or not, restrict allocations of memory for user @@ -304,15 +304,15 @@ times 1000. --------------------------- There are two boolean flag files per cpuset that control where the kernel allocates pages for the file system buffers and related in -kernel data structures. They are called 'memory_spread_page' and -'memory_spread_slab'. +kernel data structures. They are called 'cpuset.memory_spread_page' and +'cpuset.memory_spread_slab'. -If the per-cpuset boolean flag file 'memory_spread_page' is set, then +If the per-cpuset boolean flag file 'cpuset.memory_spread_page' is set, then the kernel will spread the file system buffers (page cache) evenly over all the nodes that the faulting task is allowed to use, instead of preferring to put those pages on the node where the task is running. -If the per-cpuset boolean flag file 'memory_spread_slab' is set, +If the per-cpuset boolean flag file 'cpuset.memory_spread_slab' is set, then the kernel will spread some file system related slab caches, such as for inodes and dentries evenly over all the nodes that the faulting task is allowed to use, instead of preferring to put those @@ -337,21 +337,21 @@ their containing tasks memory spread settings. If memory spreading is turned off, then the currently specified NUMA mempolicy once again applies to memory page allocations. -Both 'memory_spread_page' and 'memory_spread_slab' are boolean flag +Both 'cpuset.memory_spread_page' and 'cpuset.memory_spread_slab' are boolean flag files. By default they contain "0", meaning that the feature is off for that cpuset. If a "1" is written to that file, then that turns the named feature on. The implementation is simple. -Setting the flag 'memory_spread_page' turns on a per-process flag +Setting the flag 'cpuset.memory_spread_page' turns on a per-process flag PF_SPREAD_PAGE for each task that is in that cpuset or subsequently joins that cpuset. The page allocation calls for the page cache is modified to perform an inline check for this PF_SPREAD_PAGE task flag, and if set, a call to a new routine cpuset_mem_spread_node() returns the node to prefer for the allocation. -Similarly, setting 'memory_spread_slab' turns on the flag +Similarly, setting 'cpuset.memory_spread_slab' turns on the flag PF_SPREAD_SLAB, and appropriately marked slab caches will allocate pages from the node returned by cpuset_mem_spread_node(). @@ -404,24 +404,24 @@ the following two situations: system overhead on those CPUs, including avoiding task load balancing if that is not needed. -When the per-cpuset flag "sched_load_balance" is enabled (the default -setting), it requests that all the CPUs in that cpusets allowed 'cpus' +When the per-cpuset flag "cpuset.sched_load_balance" is enabled (the default +setting), it requests that all the CPUs in that cpusets allowed 'cpuset.cpus' be contained in a single sched domain, ensuring that load balancing can move a task (not otherwised pinned, as by sched_setaffinity) from any CPU in that cpuset to any other. -When the per-cpuset flag "sched_load_balance" is disabled, then the +When the per-cpuset flag "cpuset.sched_load_balance" is disabled, then the scheduler will avoid load balancing across the CPUs in that cpuset, --except-- in so far as is necessary because some overlapping cpuset has "sched_load_balance" enabled. -So, for example, if the top cpuset has the flag "sched_load_balance" +So, for example, if the top cpuset has the flag "cpuset.sched_load_balance" enabled, then the scheduler will have one sched domain covering all -CPUs, and the setting of the "sched_load_balance" flag in any other +CPUs, and the setting of the "cpuset.sched_load_balance" flag in any other cpusets won't matter, as we're already fully load balancing. Therefore in the above two situations, the top cpuset flag -"sched_load_balance" should be disabled, and only some of the smaller, +"cpuset.sched_load_balance" should be disabled, and only some of the smaller, child cpusets have this flag enabled. When doing this, you don't usually want to leave any unpinned tasks in @@ -433,7 +433,7 @@ scheduler might not consider the possibility of load balancing that task to that underused CPU. Of course, tasks pinned to a particular CPU can be left in a cpuset -that disables "sched_load_balance" as those tasks aren't going anywhere +that disables "cpuset.sched_load_balance" as those tasks aren't going anywhere else anyway. There is an impedance mismatch here, between cpusets and sched domains. @@ -443,19 +443,19 @@ overlap and each CPU is in at most one sched domain. It is necessary for sched domains to be flat because load balancing across partially overlapping sets of CPUs would risk unstable dynamics that would be beyond our understanding. So if each of two partially -overlapping cpusets enables the flag 'sched_load_balance', then we +overlapping cpusets enables the flag 'cpuset.sched_load_balance', then we form a single sched domain that is a superset of both. We won't move a task to a CPU outside it cpuset, but the scheduler load balancing code might waste some compute cycles considering that possibility. This mismatch is why there is not a simple one-to-one relation -between which cpusets have the flag "sched_load_balance" enabled, +between which cpusets have the flag "cpuset.sched_load_balance" enabled, and the sched domain configuration. If a cpuset enables the flag, it will get balancing across all its CPUs, but if it disables the flag, it will only be assured of no load balancing if no other overlapping cpuset enables the flag. -If two cpusets have partially overlapping 'cpus' allowed, and only +If two cpusets have partially overlapping 'cpuset.cpus' allowed, and only one of them has this flag enabled, then the other may find its tasks only partially load balanced, just on the overlapping CPUs. This is just the general case of the top_cpuset example given a few @@ -468,23 +468,23 @@ load balancing to the other CPUs. 1.7.1 sched_load_balance implementation details. ------------------------------------------------ -The per-cpuset flag 'sched_load_balance' defaults to enabled (contrary +The per-cpuset flag 'cpuset.sched_load_balance' defaults to enabled (contrary to most cpuset flags.) When enabled for a cpuset, the kernel will ensure that it can load balance across all the CPUs in that cpuset (makes sure that all the CPUs in the cpus_allowed of that cpuset are in the same sched domain.) -If two overlapping cpusets both have 'sched_load_balance' enabled, +If two overlapping cpusets both have 'cpuset.sched_load_balance' enabled, then they will be (must be) both in the same sched domain. -If, as is the default, the top cpuset has 'sched_load_balance' enabled, +If, as is the default, the top cpuset has 'cpuset.sched_load_balance' enabled, then by the above that means there is a single sched domain covering the whole system, regardless of any other cpuset settings. The kernel commits to user space that it will avoid load balancing where it can. It will pick as fine a granularity partition of sched domains as it can while still providing load balancing for any set -of CPUs allowed to a cpuset having 'sched_load_balance' enabled. +of CPUs allowed to a cpuset having 'cpuset.sched_load_balance' enabled. The internal kernel cpuset to scheduler interface passes from the cpuset code to the scheduler code a partition of the load balanced @@ -495,9 +495,9 @@ all the CPUs that must be load balanced. The cpuset code builds a new such partition and passes it to the scheduler sched domain setup code, to have the sched domains rebuilt as necessary, whenever: - - the 'sched_load_balance' flag of a cpuset with non-empty CPUs changes, + - the 'cpuset.sched_load_balance' flag of a cpuset with non-empty CPUs changes, - or CPUs come or go from a cpuset with this flag enabled, - - or 'sched_relax_domain_level' value of a cpuset with non-empty CPUs + - or 'cpuset.sched_relax_domain_level' value of a cpuset with non-empty CPUs and with this flag enabled changes, - or a cpuset with non-empty CPUs and with this flag enabled is removed, - or a cpu is offlined/onlined. @@ -542,7 +542,7 @@ As the result, task B on CPU X need to wait task A or wait load balance on the next tick. For some applications in special situation, waiting 1 tick may be too long. -The 'sched_relax_domain_level' file allows you to request changing +The 'cpuset.sched_relax_domain_level' file allows you to request changing this searching range as you like. This file takes int value which indicates size of searching range in levels ideally as follows, otherwise initial value -1 that indicates the cpuset has no request. @@ -559,8 +559,8 @@ The system default is architecture dependent. The system default can be changed using the relax_domain_level= boot parameter. This file is per-cpuset and affect the sched domain where the cpuset -belongs to. Therefore if the flag 'sched_load_balance' of a cpuset -is disabled, then 'sched_relax_domain_level' have no effect since +belongs to. Therefore if the flag 'cpuset.sched_load_balance' of a cpuset +is disabled, then 'cpuset.sched_relax_domain_level' have no effect since there is no sched domain belonging the cpuset. If multiple cpusets are overlapping and hence they form a single sched @@ -607,9 +607,9 @@ from one cpuset to another, then the kernel will adjust the tasks memory placement, as above, the next time that the kernel attempts to allocate a page of memory for that task. -If a cpuset has its 'cpus' modified, then each task in that cpuset +If a cpuset has its 'cpuset.cpus' modified, then each task in that cpuset will have its allowed CPU placement changed immediately. Similarly, -if a tasks pid is written to another cpusets 'tasks' file, then its +if a tasks pid is written to another cpusets 'cpuset.tasks' file, then its allowed CPU placement is changed immediately. If such a task had been bound to some subset of its cpuset using the sched_setaffinity() call, the task will be allowed to run on any CPU allowed in its new cpuset, @@ -622,8 +622,8 @@ and the processor placement is updated immediately. Normally, once a page is allocated (given a physical page of main memory) then that page stays on whatever node it was allocated, so long as it remains allocated, even if the -cpusets memory placement policy 'mems' subsequently changes. -If the cpuset flag file 'memory_migrate' is set true, then when +cpusets memory placement policy 'cpuset.mems' subsequently changes. +If the cpuset flag file 'cpuset.memory_migrate' is set true, then when tasks are attached to that cpuset, any pages that task had allocated to it on nodes in its previous cpuset are migrated to the tasks new cpuset. The relative placement of the page within @@ -631,12 +631,12 @@ the cpuset is preserved during these migration operations if possible. For example if the page was on the second valid node of the prior cpuset then the page will be placed on the second valid node of the new cpuset. -Also if 'memory_migrate' is set true, then if that cpusets -'mems' file is modified, pages allocated to tasks in that -cpuset, that were on nodes in the previous setting of 'mems', +Also if 'cpuset.memory_migrate' is set true, then if that cpusets +'cpuset.mems' file is modified, pages allocated to tasks in that +cpuset, that were on nodes in the previous setting of 'cpuset.mems', will be moved to nodes in the new setting of 'mems.' Pages that were not in the tasks prior cpuset, or in the cpusets -prior 'mems' setting, will not be moved. +prior 'cpuset.mems' setting, will not be moved. There is an exception to the above. If hotplug functionality is used to remove all the CPUs that are currently assigned to a cpuset, @@ -678,8 +678,8 @@ and then start a subshell 'sh' in that cpuset: cd /dev/cpuset mkdir Charlie cd Charlie - /bin/echo 2-3 > cpus - /bin/echo 1 > mems + /bin/echo 2-3 > cpuset.cpus + /bin/echo 1 > cpuset.mems /bin/echo $$ > tasks sh # The subshell 'sh' is now running in cpuset Charlie @@ -725,10 +725,13 @@ Now you want to do something with this cpuset. In this directory you can find several files: # ls -cpu_exclusive memory_migrate mems tasks -cpus memory_pressure notify_on_release -mem_exclusive memory_spread_page sched_load_balance -mem_hardwall memory_spread_slab sched_relax_domain_level +cpuset.cpu_exclusive cpuset.memory_spread_slab +cpuset.cpus cpuset.mems +cpuset.mem_exclusive cpuset.sched_load_balance +cpuset.mem_hardwall cpuset.sched_relax_domain_level +cpuset.memory_migrate notify_on_release +cpuset.memory_pressure tasks +cpuset.memory_spread_page Reading them will give you information about the state of this cpuset: the CPUs and Memory Nodes it can use, the processes that are using @@ -736,13 +739,13 @@ it, its properties. By writing to these files you can manipulate the cpuset. Set some flags: -# /bin/echo 1 > cpu_exclusive +# /bin/echo 1 > cpuset.cpu_exclusive Add some cpus: -# /bin/echo 0-7 > cpus +# /bin/echo 0-7 > cpuset.cpus Add some mems: -# /bin/echo 0-7 > mems +# /bin/echo 0-7 > cpuset.mems Now attach your shell to this cpuset: # /bin/echo $$ > tasks @@ -774,28 +777,28 @@ echo "/sbin/cpuset_release_agent" > /dev/cpuset/release_agent This is the syntax to use when writing in the cpus or mems files in cpuset directories: -# /bin/echo 1-4 > cpus -> set cpus list to cpus 1,2,3,4 -# /bin/echo 1,2,3,4 > cpus -> set cpus list to cpus 1,2,3,4 +# /bin/echo 1-4 > cpuset.cpus -> set cpus list to cpus 1,2,3,4 +# /bin/echo 1,2,3,4 > cpuset.cpus -> set cpus list to cpus 1,2,3,4 To add a CPU to a cpuset, write the new list of CPUs including the CPU to be added. To add 6 to the above cpuset: -# /bin/echo 1-4,6 > cpus -> set cpus list to cpus 1,2,3,4,6 +# /bin/echo 1-4,6 > cpuset.cpus -> set cpus list to cpus 1,2,3,4,6 Similarly to remove a CPU from a cpuset, write the new list of CPUs without the CPU to be removed. To remove all the CPUs: -# /bin/echo "" > cpus -> clear cpus list +# /bin/echo "" > cpuset.cpus -> clear cpus list 2.3 Setting flags ----------------- The syntax is very simple: -# /bin/echo 1 > cpu_exclusive -> set flag 'cpu_exclusive' -# /bin/echo 0 > cpu_exclusive -> unset flag 'cpu_exclusive' +# /bin/echo 1 > cpuset.cpu_exclusive -> set flag 'cpuset.cpu_exclusive' +# /bin/echo 0 > cpuset.cpu_exclusive -> unset flag 'cpuset.cpu_exclusive' 2.4 Attaching processes ----------------------- diff --git a/Documentation/cgroups/memcg_test.txt b/Documentation/cgroups/memcg_test.txt index 72db89ed060..f7f68b2ac19 100644 --- a/Documentation/cgroups/memcg_test.txt +++ b/Documentation/cgroups/memcg_test.txt @@ -1,6 +1,6 @@ Memory Resource Controller(Memcg) Implementation Memo. -Last Updated: 2009/1/20 -Base Kernel Version: based on 2.6.29-rc2. +Last Updated: 2010/2 +Base Kernel Version: based on 2.6.33-rc7-mm(candidate for 34). Because VM is getting complex (one of reasons is memcg...), memcg's behavior is complex. This is a document for memcg's internal behavior. @@ -337,7 +337,7 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. race and lock dependency with other cgroup subsystems. example) - # mount -t cgroup none /cgroup -t cpuset,memory,cpu,devices + # mount -t cgroup none /cgroup -o cpuset,memory,cpu,devices and do task move, mkdir, rmdir etc...under this. @@ -348,7 +348,7 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. For example, test like following is good. (Shell-A) - # mount -t cgroup none /cgroup -t memory + # mount -t cgroup none /cgroup -o memory # mkdir /cgroup/test # echo 40M > /cgroup/test/memory.limit_in_bytes # echo 0 > /cgroup/test/tasks @@ -378,3 +378,42 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. #echo 50M > memory.limit_in_bytes #echo 50M > memory.memsw.limit_in_bytes run 51M of malloc + + 9.9 Move charges at task migration + Charges associated with a task can be moved along with task migration. + + (Shell-A) + #mkdir /cgroup/A + #echo $$ >/cgroup/A/tasks + run some programs which uses some amount of memory in /cgroup/A. + + (Shell-B) + #mkdir /cgroup/B + #echo 1 >/cgroup/B/memory.move_charge_at_immigrate + #echo "pid of the program running in group A" >/cgroup/B/tasks + + You can see charges have been moved by reading *.usage_in_bytes or + memory.stat of both A and B. + See 8.2 of Documentation/cgroups/memory.txt to see what value should be + written to move_charge_at_immigrate. + + 9.10 Memory thresholds + Memory controler implements memory thresholds using cgroups notification + API. You can use Documentation/cgroups/cgroup_event_listener.c to test + it. + + (Shell-A) Create cgroup and run event listener + # mkdir /cgroup/A + # ./cgroup_event_listener /cgroup/A/memory.usage_in_bytes 5M + + (Shell-B) Add task to cgroup and try to allocate and free memory + # echo $$ >/cgroup/A/tasks + # a="$(dd if=/dev/zero bs=1M count=10)" + # a= + + You will see message from cgroup_event_listener every time you cross + the thresholds. + + Use /cgroup/A/memory.memsw.usage_in_bytes to test memsw thresholds. + + It's good idea to test root cgroup as well. diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index b871f2552b4..3a6aecd078b 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -182,6 +182,8 @@ list. NOTE: Reclaim does not work for the root cgroup, since we cannot set any limits on the root cgroup. +Note2: When panic_on_oom is set to "2", the whole system will panic. + 2. Locking The memory controller uses the following hierarchy @@ -262,10 +264,12 @@ some of the pages cached in the cgroup (page cache pages). 4.2 Task migration When a task migrates from one cgroup to another, it's charge is not -carried forward. The pages allocated from the original cgroup still +carried forward by default. The pages allocated from the original cgroup still remain charged to it, the charge is dropped when the page is freed or reclaimed. +Note: You can move charges of a task along with task migration. See 8. + 4.3 Removing a cgroup A cgroup can be removed by rmdir, but as discussed in sections 4.1 and 4.2, a @@ -336,7 +340,7 @@ Note: 5.3 swappiness Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. - Following cgroups' swapiness can't be changed. + Following cgroups' swappiness can't be changed. - root cgroup (uses /proc/sys/vm/swappiness). - a cgroup which uses hierarchy and it has child cgroup. - a cgroup which uses hierarchy and not the root of hierarchy. @@ -377,7 +381,8 @@ The feature can be disabled by NOTE1: Enabling/disabling will fail if the cgroup already has other cgroups created below it. -NOTE2: This feature can be enabled/disabled per subtree. +NOTE2: When panic_on_oom is set to "2", the whole system will panic in +case of an oom event in any cgroup. 7. Soft limits @@ -414,7 +419,76 @@ NOTE1: Soft limits take effect over a long period of time, since they involve NOTE2: It is recommended to set the soft limit always below the hard limit, otherwise the hard limit will take precedence. -8. TODO +8. Move charges at task migration + +Users can move charges associated with a task along with task migration, that +is, uncharge task's pages from the old cgroup and charge them to the new cgroup. +This feature is not supported in !CONFIG_MMU environments because of lack of +page tables. + +8.1 Interface + +This feature is disabled by default. It can be enabled(and disabled again) by +writing to memory.move_charge_at_immigrate of the destination cgroup. + +If you want to enable it: + +# echo (some positive value) > memory.move_charge_at_immigrate + +Note: Each bits of move_charge_at_immigrate has its own meaning about what type + of charges should be moved. See 8.2 for details. +Note: Charges are moved only when you move mm->owner, IOW, a leader of a thread + group. +Note: If we cannot find enough space for the task in the destination cgroup, we + try to make space by reclaiming memory. Task migration may fail if we + cannot make enough space. +Note: It can take several seconds if you move charges in giga bytes order. + +And if you want disable it again: + +# echo 0 > memory.move_charge_at_immigrate + +8.2 Type of charges which can be move + +Each bits of move_charge_at_immigrate has its own meaning about what type of +charges should be moved. + + bit | what type of charges would be moved ? + -----+------------------------------------------------------------------------ + 0 | A charge of an anonymous page(or swap of it) used by the target task. + | Those pages and swaps must be used only by the target task. You must + | enable Swap Extension(see 2.4) to enable move of swap charges. + +Note: Those pages and swaps must be charged to the old cgroup. +Note: More type of pages(e.g. file cache, shmem,) will be supported by other + bits in future. + +8.3 TODO + +- Add support for other types of pages(e.g. file cache, shmem, etc.). +- Implement madvise(2) to let users decide the vma to be moved or not to be + moved. +- All of moving charge operations are done under cgroup_mutex. It's not good + behavior to hold the mutex too long, so we may need some trick. + +9. Memory thresholds + +Memory controler implements memory thresholds using cgroups notification +API (see cgroups.txt). It allows to register multiple memory and memsw +thresholds and gets notifications when it crosses. + +To register a threshold application need: + - create an eventfd using eventfd(2); + - open memory.usage_in_bytes or memory.memsw.usage_in_bytes; + - write string like "<event_fd> <memory.usage_in_bytes> <threshold>" to + cgroup.event_control. + +Application will be notified through eventfd when memory usage crosses +threshold in any direction. + +It's applicable for root and non-root cgroup. + +10. TODO 1. Add support for accounting huge pages (as a separate controller) 2. Make per-cgroup scanner reclaim not-shared pages first diff --git a/Documentation/circular-buffers.txt b/Documentation/circular-buffers.txt new file mode 100644 index 00000000000..8117e5bf606 --- /dev/null +++ b/Documentation/circular-buffers.txt @@ -0,0 +1,234 @@ + ================ + CIRCULAR BUFFERS + ================ + +By: David Howells <dhowells@redhat.com> + Paul E. McKenney <paulmck@linux.vnet.ibm.com> + + +Linux provides a number of features that can be used to implement circular +buffering. There are two sets of such features: + + (1) Convenience functions for determining information about power-of-2 sized + buffers. + + (2) Memory barriers for when the producer and the consumer of objects in the + buffer don't want to share a lock. + +To use these facilities, as discussed below, there needs to be just one +producer and just one consumer. It is possible to handle multiple producers by +serialising them, and to handle multiple consumers by serialising them. + + +Contents: + + (*) What is a circular buffer? + + (*) Measuring power-of-2 buffers. + + (*) Using memory barriers with circular buffers. + - The producer. + - The consumer. + + +========================== +WHAT IS A CIRCULAR BUFFER? +========================== + +First of all, what is a circular buffer? A circular buffer is a buffer of +fixed, finite size into which there are two indices: + + (1) A 'head' index - the point at which the producer inserts items into the + buffer. + + (2) A 'tail' index - the point at which the consumer finds the next item in + the buffer. + +Typically when the tail pointer is equal to the head pointer, the buffer is +empty; and the buffer is full when the head pointer is one less than the tail +pointer. + +The head index is incremented when items are added, and the tail index when +items are removed. The tail index should never jump the head index, and both +indices should be wrapped to 0 when they reach the end of the buffer, thus +allowing an infinite amount of data to flow through the buffer. + +Typically, items will all be of the same unit size, but this isn't strictly +required to use the techniques below. The indices can be increased by more +than 1 if multiple items or variable-sized items are to be included in the +buffer, provided that neither index overtakes the other. The implementer must +be careful, however, as a region more than one unit in size may wrap the end of +the buffer and be broken into two segments. + + +============================ +MEASURING POWER-OF-2 BUFFERS +============================ + +Calculation of the occupancy or the remaining capacity of an arbitrarily sized +circular buffer would normally be a slow operation, requiring the use of a +modulus (divide) instruction. However, if the buffer is of a power-of-2 size, +then a much quicker bitwise-AND instruction can be used instead. + +Linux provides a set of macros for handling power-of-2 circular buffers. These +can be made use of by: + + #include <linux/circ_buf.h> + +The macros are: + + (*) Measure the remaining capacity of a buffer: + + CIRC_SPACE(head_index, tail_index, buffer_size); + + This returns the amount of space left in the buffer[1] into which items + can be inserted. + + + (*) Measure the maximum consecutive immediate space in a buffer: + + CIRC_SPACE_TO_END(head_index, tail_index, buffer_size); + + This returns the amount of consecutive space left in the buffer[1] into + which items can be immediately inserted without having to wrap back to the + beginning of the buffer. + + + (*) Measure the occupancy of a buffer: + + CIRC_CNT(head_index, tail_index, buffer_size); + + This returns the number of items currently occupying a buffer[2]. + + + (*) Measure the non-wrapping occupancy of a buffer: + + CIRC_CNT_TO_END(head_index, tail_index, buffer_size); + + This returns the number of consecutive items[2] that can be extracted from + the buffer without having to wrap back to the beginning of the buffer. + + +Each of these macros will nominally return a value between 0 and buffer_size-1, +however: + + [1] CIRC_SPACE*() are intended to be used in the producer. To the producer + they will return a lower bound as the producer controls the head index, + but the consumer may still be depleting the buffer on another CPU and + moving the tail index. + + To the consumer it will show an upper bound as the producer may be busy + depleting the space. + + [2] CIRC_CNT*() are intended to be used in the consumer. To the consumer they + will return a lower bound as the consumer controls the tail index, but the + producer may still be filling the buffer on another CPU and moving the + head index. + + To the producer it will show an upper bound as the consumer may be busy + emptying the buffer. + + [3] To a third party, the order in which the writes to the indices by the + producer and consumer become visible cannot be guaranteed as they are + independent and may be made on different CPUs - so the result in such a + situation will merely be a guess, and may even be negative. + + +=========================================== +USING MEMORY BARRIERS WITH CIRCULAR BUFFERS +=========================================== + +By using memory barriers in conjunction with circular buffers, you can avoid +the need to: + + (1) use a single lock to govern access to both ends of the buffer, thus + allowing the buffer to be filled and emptied at the same time; and + + (2) use atomic counter operations. + +There are two sides to this: the producer that fills the buffer, and the +consumer that empties it. Only one thing should be filling a buffer at any one +time, and only one thing should be emptying a buffer at any one time, but the +two sides can operate simultaneously. + + +THE PRODUCER +------------ + +The producer will look something like this: + + spin_lock(&producer_lock); + + unsigned long head = buffer->head; + unsigned long tail = ACCESS_ONCE(buffer->tail); + + if (CIRC_SPACE(head, tail, buffer->size) >= 1) { + /* insert one item into the buffer */ + struct item *item = buffer[head]; + + produce_item(item); + + smp_wmb(); /* commit the item before incrementing the head */ + + buffer->head = (head + 1) & (buffer->size - 1); + + /* wake_up() will make sure that the head is committed before + * waking anyone up */ + wake_up(consumer); + } + + spin_unlock(&producer_lock); + +This will instruct the CPU that the contents of the new item must be written +before the head index makes it available to the consumer and then instructs the +CPU that the revised head index must be written before the consumer is woken. + +Note that wake_up() doesn't have to be the exact mechanism used, but whatever +is used must guarantee a (write) memory barrier between the update of the head +index and the change of state of the consumer, if a change of state occurs. + + +THE CONSUMER +------------ + +The consumer will look something like this: + + spin_lock(&consumer_lock); + + unsigned long head = ACCESS_ONCE(buffer->head); + unsigned long tail = buffer->tail; + + if (CIRC_CNT(head, tail, buffer->size) >= 1) { + /* read index before reading contents at that index */ + smp_read_barrier_depends(); + + /* extract one item from the buffer */ + struct item *item = buffer[tail]; + + consume_item(item); + + smp_mb(); /* finish reading descriptor before incrementing tail */ + + buffer->tail = (tail + 1) & (buffer->size - 1); + } + + spin_unlock(&consumer_lock); + +This will instruct the CPU to make sure the index is up to date before reading +the new item, and then it shall make sure the CPU has finished reading the item +before it writes the new tail pointer, which will erase the item. + + +Note the use of ACCESS_ONCE() in both algorithms to read the opposition index. +This prevents the compiler from discarding and reloading its cached value - +which some compilers will do across smp_read_barrier_depends(). This isn't +strictly needed if you can be sure that the opposition index will _only_ be +used the once. + + +=============== +FURTHER READING +=============== + +See also Documentation/memory-barriers.txt for a description of Linux's memory +barrier facilities. diff --git a/Documentation/connector/cn_test.c b/Documentation/connector/cn_test.c index b07add3467f..7764594778d 100644 --- a/Documentation/connector/cn_test.c +++ b/Documentation/connector/cn_test.c @@ -25,6 +25,7 @@ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/skbuff.h> +#include <linux/slab.h> #include <linux/timer.h> #include <linux/connector.h> diff --git a/Documentation/console/console.txt b/Documentation/console/console.txt index 877a1b26cc3..926cf1b5e63 100644 --- a/Documentation/console/console.txt +++ b/Documentation/console/console.txt @@ -74,7 +74,7 @@ driver takes over the consoles vacated by the driver. Binding, on the other hand, will bind the driver to the consoles that are currently occupied by a system driver. -NOTE1: Binding and binding must be selected in Kconfig. It's under: +NOTE1: Binding and unbinding must be selected in Kconfig. It's under: Device Drivers -> Character devices -> Support for binding and unbinding console drivers diff --git a/Documentation/driver-model/platform.txt b/Documentation/driver-model/platform.txt index 2e2c2ea90ce..41f41632ee5 100644 --- a/Documentation/driver-model/platform.txt +++ b/Documentation/driver-model/platform.txt @@ -192,7 +192,7 @@ command line. This will execute all matching early_param() callbacks. User specified early platform devices will be registered at this point. For the early serial console case the user can specify port on the kernel command line as "earlyprintk=serial.0" where "earlyprintk" is -the class string, "serial" is the name of the platfrom driver and +the class string, "serial" is the name of the platform driver and 0 is the platform device id. If the id is -1 then the dot and the id can be omitted. diff --git a/Documentation/eisa.txt b/Documentation/eisa.txt index 60e361ba08c..f297fc1202a 100644 --- a/Documentation/eisa.txt +++ b/Documentation/eisa.txt @@ -171,7 +171,7 @@ device. virtual_root.force_probe : Force the probing code to probe EISA slots even when it cannot find an -EISA compliant mainboard (nothing appears on slot 0). Defaultd to 0 +EISA compliant mainboard (nothing appears on slot 0). Defaults to 0 (don't force), and set to 1 (force probing) when either CONFIG_ALPHA_JENSEN or CONFIG_EISA_VLB_PRIMING are set. diff --git a/Documentation/email-clients.txt b/Documentation/email-clients.txt index a618efab7b1..945ff3fda43 100644 --- a/Documentation/email-clients.txt +++ b/Documentation/email-clients.txt @@ -216,26 +216,14 @@ Works. Use "Insert file..." or external editor. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Gmail (Web GUI) -If you just have to use Gmail to send patches, it CAN be made to work. It -requires a bit of external help, though. - -The first problem is that Gmail converts tabs to spaces. This will -totally break your patches. To prevent this, you have to use a different -editor. There is a firefox extension called "ViewSourceWith" -(https://addons.mozilla.org/en-US/firefox/addon/394) which allows you to -edit any text box in the editor of your choice. Configure it to launch -your favorite editor. When you want to send a patch, use this technique. -Once you have crafted your messsage + patch, save and exit the editor, -which should reload the Gmail edit box. GMAIL WILL PRESERVE THE TABS. -Hoorah. Apparently you can cut-n-paste literal tabs, but Gmail will -convert those to spaces upon sending! - -The second problem is that Gmail converts tabs to spaces on replies. If -you reply to a patch, don't expect to be able to apply it as a patch. - -The last problem is that Gmail will base64-encode any message that has a -non-ASCII character. That includes things like European names. Be aware. - -Gmail is not convenient for lkml patches, but CAN be made to work. +Does not work for sending patches. + +Gmail web client converts tabs to spaces automatically. + +At the same time it wraps lines every 78 chars with CRLF style line breaks +although tab2space problem can be solved with external editor. + +Another problem is that Gmail will base64-encode any message that has a +non-ASCII character. That includes things like European names. ### diff --git a/Documentation/fb/imacfb.txt b/Documentation/fb/efifb.txt index 316ec9bb7de..a59916c29b3 100644 --- a/Documentation/fb/imacfb.txt +++ b/Documentation/fb/efifb.txt @@ -1,9 +1,9 @@ -What is imacfb? +What is efifb? =============== This is a generic EFI platform driver for Intel based Apple computers. -Imacfb is only for EFI booted Intel Macs. +efifb is only for EFI booted Intel Macs. Supported Hardware ================== @@ -16,16 +16,16 @@ MacMini How to use it? ============== -Imacfb does not have any kind of autodetection of your machine. +efifb does not have any kind of autodetection of your machine. You have to add the following kernel parameters in your elilo.conf: Macbook : - video=imacfb:macbook + video=efifb:macbook MacMini : - video=imacfb:mini + video=efifb:mini Macbook Pro 15", iMac 17" : - video=imacfb:i17 + video=efifb:i17 Macbook Pro 17", iMac 20" : - video=imacfb:i20 + video=efifb:i20 -- Edgar Hucek <gimli@dark-green.com> diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index a5cc0db63d7..ed511af0f79 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -582,3 +582,10 @@ Why: The paravirt mmu host support is slower than non-paravirt mmu, both Who: Avi Kivity <avi@redhat.com> ---------------------------- + +What: "acpi=ht" boot option +When: 2.6.35 +Why: Useful in 2003, implementation is a hack. + Generally invoked by accident today. + Seen as doing more harm than good. +Who: Len Brown <len.brown@intel.com> diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX index 5139b8c9d5a..4303614b5ad 100644 --- a/Documentation/filesystems/00-INDEX +++ b/Documentation/filesystems/00-INDEX @@ -16,6 +16,8 @@ befs.txt - information about the BeOS filesystem for Linux. bfs.txt - info for the SCO UnixWare Boot Filesystem (BFS). +ceph.txt + - info for the Ceph Distributed File System cifs.txt - description of the CIFS filesystem. coda.txt @@ -32,6 +34,8 @@ dlmfs.txt - info on the userspace interface to the OCFS2 DLM. dnotify.txt - info about directory notification in Linux. +dnotify_test.c + - example program for dnotify ecryptfs.txt - docs on eCryptfs: stacked cryptographic filesystem for Linux. exofs.txt diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt index 57e0b80a527..c0236e753bc 100644 --- a/Documentation/filesystems/9p.txt +++ b/Documentation/filesystems/9p.txt @@ -37,6 +37,15 @@ For Plan 9 From User Space applications (http://swtch.com/plan9) mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER +For server running on QEMU host with virtio transport: + + mount -t 9p -o trans=virtio <mount_tag> /mnt/9 + +where mount_tag is the tag associated by the server to each of the exported +mount points. Each 9P export is seen by the client as a virtio device with an +associated "mount_tag" property. Available mount tags can be +seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files. + OPTIONS ======= @@ -47,7 +56,7 @@ OPTIONS fd - used passed file descriptors for connection (see rfdno and wfdno) virtio - connect to the next virtio channel available - (from lguest or KVM with trans_virtio module) + (from QEMU with trans_virtio module) rdma - connect to a specified RDMA channel uname=name user name to attempt mount as on the remote server. The @@ -85,7 +94,12 @@ OPTIONS port=n port to connect to on the remote server - noextend force legacy mode (no 9p2000.u semantics) + noextend force legacy mode (no 9p2000.u or 9p2000.L semantics) + + version=name Select 9P protocol version. Valid options are: + 9p2000 - Legacy mode (same as noextend) + 9p2000.u - Use 9P2000.u protocol + 9p2000.L - Use 9P2000.L protocol dfltuid attempt to mount as a particular uid diff --git a/Documentation/filesystems/Makefile b/Documentation/filesystems/Makefile new file mode 100644 index 00000000000..a5dd114da14 --- /dev/null +++ b/Documentation/filesystems/Makefile @@ -0,0 +1,8 @@ +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o + +# List of programs to build +hostprogs-y := dnotify_test + +# Tell kbuild to always build the programs +always := $(hostprogs-y) diff --git a/Documentation/filesystems/ceph.txt b/Documentation/filesystems/ceph.txt new file mode 100644 index 00000000000..0660c9f5dee --- /dev/null +++ b/Documentation/filesystems/ceph.txt @@ -0,0 +1,140 @@ +Ceph Distributed File System +============================ + +Ceph is a distributed network file system designed to provide good +performance, reliability, and scalability. + +Basic features include: + + * POSIX semantics + * Seamless scaling from 1 to many thousands of nodes + * High availability and reliability. No single point of failure. + * N-way replication of data across storage nodes + * Fast recovery from node failures + * Automatic rebalancing of data on node addition/removal + * Easy deployment: most FS components are userspace daemons + +Also, + * Flexible snapshots (on any directory) + * Recursive accounting (nested files, directories, bytes) + +In contrast to cluster filesystems like GFS, OCFS2, and GPFS that rely +on symmetric access by all clients to shared block devices, Ceph +separates data and metadata management into independent server +clusters, similar to Lustre. Unlike Lustre, however, metadata and +storage nodes run entirely as user space daemons. Storage nodes +utilize btrfs to store data objects, leveraging its advanced features +(checksumming, metadata replication, etc.). File data is striped +across storage nodes in large chunks to distribute workload and +facilitate high throughputs. When storage nodes fail, data is +re-replicated in a distributed fashion by the storage nodes themselves +(with some minimal coordination from a cluster monitor), making the +system extremely efficient and scalable. + +Metadata servers effectively form a large, consistent, distributed +in-memory cache above the file namespace that is extremely scalable, +dynamically redistributes metadata in response to workload changes, +and can tolerate arbitrary (well, non-Byzantine) node failures. The +metadata server takes a somewhat unconventional approach to metadata +storage to significantly improve performance for common workloads. In +particular, inodes with only a single link are embedded in +directories, allowing entire directories of dentries and inodes to be +loaded into its cache with a single I/O operation. The contents of +extremely large directories can be fragmented and managed by +independent metadata servers, allowing scalable concurrent access. + +The system offers automatic data rebalancing/migration when scaling +from a small cluster of just a few nodes to many hundreds, without +requiring an administrator carve the data set into static volumes or +go through the tedious process of migrating data between servers. +When the file system approaches full, new nodes can be easily added +and things will "just work." + +Ceph includes flexible snapshot mechanism that allows a user to create +a snapshot on any subdirectory (and its nested contents) in the +system. Snapshot creation and deletion are as simple as 'mkdir +.snap/foo' and 'rmdir .snap/foo'. + +Ceph also provides some recursive accounting on directories for nested +files and bytes. That is, a 'getfattr -d foo' on any directory in the +system will reveal the total number of nested regular files and +subdirectories, and a summation of all nested file sizes. This makes +the identification of large disk space consumers relatively quick, as +no 'du' or similar recursive scan of the file system is required. + + +Mount Syntax +============ + +The basic mount syntax is: + + # mount -t ceph monip[:port][,monip2[:port]...]:/[subdir] mnt + +You only need to specify a single monitor, as the client will get the +full list when it connects. (However, if the monitor you specify +happens to be down, the mount won't succeed.) The port can be left +off if the monitor is using the default. So if the monitor is at +1.2.3.4, + + # mount -t ceph 1.2.3.4:/ /mnt/ceph + +is sufficient. If /sbin/mount.ceph is installed, a hostname can be +used instead of an IP address. + + + +Mount Options +============= + + ip=A.B.C.D[:N] + Specify the IP and/or port the client should bind to locally. + There is normally not much reason to do this. If the IP is not + specified, the client's IP address is determined by looking at the + address it's connection to the monitor originates from. + + wsize=X + Specify the maximum write size in bytes. By default there is no + maximum. Ceph will normally size writes based on the file stripe + size. + + rsize=X + Specify the maximum readahead. + + mount_timeout=X + Specify the timeout value for mount (in seconds), in the case + of a non-responsive Ceph file system. The default is 30 + seconds. + + rbytes + When stat() is called on a directory, set st_size to 'rbytes', + the summation of file sizes over all files nested beneath that + directory. This is the default. + + norbytes + When stat() is called on a directory, set st_size to the + number of entries in that directory. + + nocrc + Disable CRC32C calculation for data writes. If set, the storage node + must rely on TCP's error correction to detect data corruption + in the data payload. + + noasyncreaddir + Disable client's use its local cache to satisfy readdir + requests. (This does not change correctness; the client uses + cached metadata only when a lease or capability ensures it is + valid.) + + +More Information +================ + +For more information on Ceph, see the home page at + http://ceph.newdream.net/ + +The Linux kernel client source tree is available at + git://ceph.newdream.net/git/ceph-client.git + git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git + +and the source for the full system is at + git://ceph.newdream.net/git/ceph.git diff --git a/Documentation/filesystems/dnotify.txt b/Documentation/filesystems/dnotify.txt index 9f5d338ddbb..6baf88f4685 100644 --- a/Documentation/filesystems/dnotify.txt +++ b/Documentation/filesystems/dnotify.txt @@ -62,38 +62,9 @@ disabled, fcntl(fd, F_NOTIFY, ...) will return -EINVAL. Example ------- +See Documentation/filesystems/dnotify_test.c for an example. - #define _GNU_SOURCE /* needed to get the defines */ - #include <fcntl.h> /* in glibc 2.2 this has the needed - values defined */ - #include <signal.h> - #include <stdio.h> - #include <unistd.h> - - static volatile int event_fd; - - static void handler(int sig, siginfo_t *si, void *data) - { - event_fd = si->si_fd; - } - - int main(void) - { - struct sigaction act; - int fd; - - act.sa_sigaction = handler; - sigemptyset(&act.sa_mask); - act.sa_flags = SA_SIGINFO; - sigaction(SIGRTMIN + 1, &act, NULL); - - fd = open(".", O_RDONLY); - fcntl(fd, F_SETSIG, SIGRTMIN + 1); - fcntl(fd, F_NOTIFY, DN_MODIFY|DN_CREATE|DN_MULTISHOT); - /* we will now be notified if any of the files - in "." is modified or new files are created */ - while (1) { - pause(); - printf("Got event on fd=%d\n", event_fd); - } - } +NOTE +---- +Beginning with Linux 2.6.13, dnotify has been replaced by inotify. +See Documentation/filesystems/inotify.txt for more information on it. diff --git a/Documentation/filesystems/dnotify_test.c b/Documentation/filesystems/dnotify_test.c new file mode 100644 index 00000000000..8b37b4a1e18 --- /dev/null +++ b/Documentation/filesystems/dnotify_test.c @@ -0,0 +1,34 @@ +#define _GNU_SOURCE /* needed to get the defines */ +#include <fcntl.h> /* in glibc 2.2 this has the needed + values defined */ +#include <signal.h> +#include <stdio.h> +#include <unistd.h> + +static volatile int event_fd; + +static void handler(int sig, siginfo_t *si, void *data) +{ + event_fd = si->si_fd; +} + +int main(void) +{ + struct sigaction act; + int fd; + + act.sa_sigaction = handler; + sigemptyset(&act.sa_mask); + act.sa_flags = SA_SIGINFO; + sigaction(SIGRTMIN + 1, &act, NULL); + + fd = open(".", O_RDONLY); + fcntl(fd, F_SETSIG, SIGRTMIN + 1); + fcntl(fd, F_NOTIFY, DN_MODIFY|DN_CREATE|DN_MULTISHOT); + /* we will now be notified if any of the files + in "." is modified or new files are created */ + while (1) { + pause(); + printf("Got event on fd=%d\n", event_fd); + } +} diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 96a44dd95e0..a4f30faa4f1 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -195,7 +195,7 @@ asynchronous manner and the vaule may not be very precise. To see a precise snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table. It's slow but very precise. -Table 1-2: Contents of the statm files (as of 2.6.30-rc7) +Table 1-2: Contents of the status files (as of 2.6.30-rc7) .............................................................................. Field Content Name filename of the executable diff --git a/Documentation/filesystems/tmpfs.txt b/Documentation/filesystems/tmpfs.txt index 3015da0c6b2..fe09a2cb185 100644 --- a/Documentation/filesystems/tmpfs.txt +++ b/Documentation/filesystems/tmpfs.txt @@ -82,11 +82,13 @@ tmpfs has a mount option to set the NUMA memory allocation policy for all files in that instance (if CONFIG_NUMA is enabled) - which can be adjusted on the fly via 'mount -o remount ...' -mpol=default prefers to allocate memory from the local node +mpol=default use the process allocation policy + (see set_mempolicy(2)) mpol=prefer:Node prefers to allocate memory from the given Node mpol=bind:NodeList allocates memory only from nodes in NodeList mpol=interleave prefers to allocate from each node in turn mpol=interleave:NodeList allocates from each node of NodeList in turn +mpol=local prefers to allocate memory from the local node NodeList format is a comma-separated list of decimal numbers and ranges, a range being two hyphen-separated decimal numbers, the smallest and @@ -134,3 +136,5 @@ Author: Christoph Rohland <cr@sap.com>, 1.12.01 Updated: Hugh Dickins, 4 June 2007 +Updated: + KOSAKI Motohiro, 16 Mar 2010 diff --git a/Documentation/hwmon/abituguru b/Documentation/hwmon/abituguru index 87ffa0f5ec7..5eb3b9d5f0d 100644 --- a/Documentation/hwmon/abituguru +++ b/Documentation/hwmon/abituguru @@ -30,7 +30,7 @@ Supported chips: bank1_types=1,1,0,0,0,0,0,2,0,0,0,0,2,0,0,1 You may also need to specify the fan_sensors option for these boards fan_sensors=5 - 2) There is a seperate abituguru3 driver for these motherboards, + 2) There is a separate abituguru3 driver for these motherboards, the abituguru (without the 3 !) driver will not work on these motherboards (and visa versa)! diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index 3219ee0dbfe..5ebf5af1d71 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -74,6 +74,11 @@ structure at all. You should use this to keep device-specific data. /* retrieve the value */ void *i2c_get_clientdata(const struct i2c_client *client); +Note that starting with kernel 2.6.34, you don't have to set the `data' field +to NULL in remove() or if probe() failed anymore. The i2c-core does this +automatically on these occasions. Those are also the only times the core will +touch this field. + Accessing the client ==================== diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt index 3a6aec40c0b..8b4129de1d2 100644 --- a/Documentation/input/rotary-encoder.txt +++ b/Documentation/input/rotary-encoder.txt @@ -75,7 +75,7 @@ and the number of steps or will clamp at the maximum and zero depending on the configuration. Because GPIO to IRQ mapping is platform specific, this information must -be given in seperately to the driver. See the example below. +be given in separately to the driver. See the example below. ---------<snip>--------- diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index 35c9b51d20e..dd5806f4fcc 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -291,6 +291,7 @@ Code Seq#(hex) Include File Comments 0x92 00-0F drivers/usb/mon/mon_bin.c 0x93 60-7F linux/auto_fs.h 0x94 all fs/btrfs/ioctl.h +0x97 00-7F fs/ceph/ioctl.h Ceph file system 0x99 00-0F 537-Addinboard driver <mailto:buk@buks.ipn.de> 0xA0 all linux/sdp/sdp.h Industrial Device Project diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 3bc48b0bd3a..839b21b0699 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -200,10 +200,6 @@ and is between 256 and 4096 characters. It is defined in the file acpi_display_output=video See above. - acpi_early_pdc_eval [HW,ACPI] Evaluate processor _PDC methods - early. Needed on some platforms to properly - initialize the EC. - acpi_irq_balance [HW,ACPI] ACPI will balance active IRQs default in APIC mode @@ -324,11 +320,6 @@ and is between 256 and 4096 characters. It is defined in the file amd_iommu= [HW,X86-84] Pass parameters to the AMD IOMMU driver in the system. Possible values are: - isolate - enable device isolation (each device, as far - as possible, will get its own protection - domain) [default] - share - put every device behind one IOMMU into the - same protection domain fullflush - enable flushing of IO/TLB entries when they are unmapped. Otherwise they are flushed before they will be reused, which @@ -1203,7 +1194,7 @@ and is between 256 and 4096 characters. It is defined in the file libata.force= [LIBATA] Force configurations. The format is comma separated list of "[ID:]VAL" where ID is - PORT[:DEVICE]. PORT and DEVICE are decimal numbers + PORT[.DEVICE]. PORT and DEVICE are decimal numbers matching port, link or device. Basically, it matches the ATA ID string printed on console by libata. If the whole ID part is omitted, the last PORT and DEVICE diff --git a/Documentation/kobject.txt b/Documentation/kobject.txt index bdb13817e1e..3ab2472509c 100644 --- a/Documentation/kobject.txt +++ b/Documentation/kobject.txt @@ -59,37 +59,56 @@ nice to have in other objects. The C language does not allow for the direct expression of inheritance, so other techniques - such as structure embedding - must be used. -So, for example, the UIO code has a structure that defines the memory -region associated with a uio device: +(As an aside, for those familiar with the kernel linked list implementation, +this is analogous as to how "list_head" structs are rarely useful on +their own, but are invariably found embedded in the larger objects of +interest.) -struct uio_mem { +So, for example, the UIO code in drivers/uio/uio.c has a structure that +defines the memory region associated with a uio device: + + struct uio_map { struct kobject kobj; - unsigned long addr; - unsigned long size; - int memtype; - void __iomem *internal_addr; -}; + struct uio_mem *mem; + }; -If you have a struct uio_mem structure, finding its embedded kobject is +If you have a struct uio_map structure, finding its embedded kobject is just a matter of using the kobj member. Code that works with kobjects will often have the opposite problem, however: given a struct kobject pointer, what is the pointer to the containing structure? You must avoid tricks (such as assuming that the kobject is at the beginning of the structure) and, instead, use the container_of() macro, found in <linux/kernel.h>: - container_of(pointer, type, member) + container_of(pointer, type, member) + +where: + + * "pointer" is the pointer to the embedded kobject, + * "type" is the type of the containing structure, and + * "member" is the name of the structure field to which "pointer" points. + +The return value from container_of() is a pointer to the corresponding +container type. So, for example, a pointer "kp" to a struct kobject +embedded *within* a struct uio_map could be converted to a pointer to the +*containing* uio_map structure with: + + struct uio_map *u_map = container_of(kp, struct uio_map, kobj); + +For convenience, programmers often define a simple macro for "back-casting" +kobject pointers to the containing type. Exactly this happens in the +earlier drivers/uio/uio.c, as you can see here: + + struct uio_map { + struct kobject kobj; + struct uio_mem *mem; + }; -where pointer is the pointer to the embedded kobject, type is the type of -the containing structure, and member is the name of the structure field to -which pointer points. The return value from container_of() is a pointer to -the given type. So, for example, a pointer "kp" to a struct kobject -embedded within a struct uio_mem could be converted to a pointer to the -containing uio_mem structure with: + #define to_map(map) container_of(map, struct uio_map, kobj) - struct uio_mem *u_mem = container_of(kp, struct uio_mem, kobj); +where the macro argument "map" is a pointer to the struct kobject in +question. That macro is subsequently invoked with: -Programmers often define a simple macro for "back-casting" kobject pointers -to the containing type. + struct uio_map *map = to_map(kobj); Initialization of kobjects @@ -387,4 +406,5 @@ called, and the objects in the former circle release each other. Example code to copy from For a more complete example of using ksets and kobjects properly, see the -sample/kobject/kset-example.c code. +example programs samples/kobject/{kobject-example.c,kset-example.c}, +which will be built as loadable modules if you select CONFIG_SAMPLE_KOBJECT. diff --git a/Documentation/laptops/00-INDEX b/Documentation/laptops/00-INDEX index ee5692b26dd..fa688538e75 100644 --- a/Documentation/laptops/00-INDEX +++ b/Documentation/laptops/00-INDEX @@ -2,6 +2,12 @@ - This file acer-wmi.txt - information on the Acer Laptop WMI Extras driver. +asus-laptop.txt + - information on the Asus Laptop Extras driver. +disk-shock-protection.txt + - information on hard disk shock protection. +dslm.c + - Simple Disk Sleep Monitor program laptop-mode.txt - how to conserve battery power using laptop-mode. sony-laptop.txt diff --git a/Documentation/laptops/Makefile b/Documentation/laptops/Makefile new file mode 100644 index 00000000000..5cb144af3c0 --- /dev/null +++ b/Documentation/laptops/Makefile @@ -0,0 +1,8 @@ +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o + +# List of programs to build +hostprogs-y := dslm + +# Tell kbuild to always build the programs +always := $(hostprogs-y) diff --git a/Documentation/laptops/dslm.c b/Documentation/laptops/dslm.c new file mode 100644 index 00000000000..72ff290c5fc --- /dev/null +++ b/Documentation/laptops/dslm.c @@ -0,0 +1,166 @@ +/* + * dslm.c + * Simple Disk Sleep Monitor + * by Bartek Kania + * Licenced under the GPL + */ +#include <unistd.h> +#include <stdlib.h> +#include <stdio.h> +#include <fcntl.h> +#include <errno.h> +#include <time.h> +#include <string.h> +#include <signal.h> +#include <sys/ioctl.h> +#include <linux/hdreg.h> + +#ifdef DEBUG +#define D(x) x +#else +#define D(x) +#endif + +int endit = 0; + +/* Check if the disk is in powersave-mode + * Most of the code is stolen from hdparm. + * 1 = active, 0 = standby/sleep, -1 = unknown */ +static int check_powermode(int fd) +{ + unsigned char args[4] = {WIN_CHECKPOWERMODE1,0,0,0}; + int state; + + if (ioctl(fd, HDIO_DRIVE_CMD, &args) + && (args[0] = WIN_CHECKPOWERMODE2) /* try again with 0x98 */ + && ioctl(fd, HDIO_DRIVE_CMD, &args)) { + if (errno != EIO || args[0] != 0 || args[1] != 0) { + state = -1; /* "unknown"; */ + } else + state = 0; /* "sleeping"; */ + } else { + state = (args[2] == 255) ? 1 : 0; + } + D(printf(" drive state is: %d\n", state)); + + return state; +} + +static char *state_name(int i) +{ + if (i == -1) return "unknown"; + if (i == 0) return "sleeping"; + if (i == 1) return "active"; + + return "internal error"; +} + +static char *myctime(time_t time) +{ + char *ts = ctime(&time); + ts[strlen(ts) - 1] = 0; + + return ts; +} + +static void measure(int fd) +{ + time_t start_time; + int last_state; + time_t last_time; + int curr_state; + time_t curr_time = 0; + time_t time_diff; + time_t active_time = 0; + time_t sleep_time = 0; + time_t unknown_time = 0; + time_t total_time = 0; + int changes = 0; + float tmp; + + printf("Starting measurements\n"); + + last_state = check_powermode(fd); + start_time = last_time = time(0); + printf(" System is in state %s\n\n", state_name(last_state)); + + while(!endit) { + sleep(1); + curr_state = check_powermode(fd); + + if (curr_state != last_state || endit) { + changes++; + curr_time = time(0); + time_diff = curr_time - last_time; + + if (last_state == 1) active_time += time_diff; + else if (last_state == 0) sleep_time += time_diff; + else unknown_time += time_diff; + + last_state = curr_state; + last_time = curr_time; + + printf("%s: State-change to %s\n", myctime(curr_time), + state_name(curr_state)); + } + } + changes--; /* Compensate for SIGINT */ + + total_time = time(0) - start_time; + printf("\nTotal running time: %lus\n", curr_time - start_time); + printf(" State changed %d times\n", changes); + + tmp = (float)sleep_time / (float)total_time * 100; + printf(" Time in sleep state: %lus (%.2f%%)\n", sleep_time, tmp); + tmp = (float)active_time / (float)total_time * 100; + printf(" Time in active state: %lus (%.2f%%)\n", active_time, tmp); + tmp = (float)unknown_time / (float)total_time * 100; + printf(" Time in unknown state: %lus (%.2f%%)\n", unknown_time, tmp); +} + +static void ender(int s) +{ + endit = 1; +} + +static void usage(void) +{ + puts("usage: dslm [-w <time>] <disk>"); + exit(0); +} + +int main(int argc, char **argv) +{ + int fd; + char *disk = 0; + int settle_time = 60; + + /* Parse the simple command-line */ + if (argc == 2) + disk = argv[1]; + else if (argc == 4) { + settle_time = atoi(argv[2]); + disk = argv[3]; + } else + usage(); + + if (!(fd = open(disk, O_RDONLY|O_NONBLOCK))) { + printf("Can't open %s, because: %s\n", disk, strerror(errno)); + exit(-1); + } + + if (settle_time) { + printf("Waiting %d seconds for the system to settle down to " + "'normal'\n", settle_time); + sleep(settle_time); + } else + puts("Not waiting for system to settle down"); + + signal(SIGINT, ender); + + measure(fd); + + close(fd); + + return 0; +} diff --git a/Documentation/laptops/laptop-mode.txt b/Documentation/laptops/laptop-mode.txt index eeedee11c8c..2c3c3509302 100644 --- a/Documentation/laptops/laptop-mode.txt +++ b/Documentation/laptops/laptop-mode.txt @@ -779,172 +779,4 @@ Monitoring tool --------------- Bartek Kania submitted this, it can be used to measure how much time your disk -spends spun up/down. - ----------------------------dslm.c BEGIN----------------------------------------- -/* - * Simple Disk Sleep Monitor - * by Bartek Kania - * Licenced under the GPL - */ -#include <unistd.h> -#include <stdlib.h> -#include <stdio.h> -#include <fcntl.h> -#include <errno.h> -#include <time.h> -#include <string.h> -#include <signal.h> -#include <sys/ioctl.h> -#include <linux/hdreg.h> - -#ifdef DEBUG -#define D(x) x -#else -#define D(x) -#endif - -int endit = 0; - -/* Check if the disk is in powersave-mode - * Most of the code is stolen from hdparm. - * 1 = active, 0 = standby/sleep, -1 = unknown */ -int check_powermode(int fd) -{ - unsigned char args[4] = {WIN_CHECKPOWERMODE1,0,0,0}; - int state; - - if (ioctl(fd, HDIO_DRIVE_CMD, &args) - && (args[0] = WIN_CHECKPOWERMODE2) /* try again with 0x98 */ - && ioctl(fd, HDIO_DRIVE_CMD, &args)) { - if (errno != EIO || args[0] != 0 || args[1] != 0) { - state = -1; /* "unknown"; */ - } else - state = 0; /* "sleeping"; */ - } else { - state = (args[2] == 255) ? 1 : 0; - } - D(printf(" drive state is: %d\n", state)); - - return state; -} - -char *state_name(int i) -{ - if (i == -1) return "unknown"; - if (i == 0) return "sleeping"; - if (i == 1) return "active"; - - return "internal error"; -} - -char *myctime(time_t time) -{ - char *ts = ctime(&time); - ts[strlen(ts) - 1] = 0; - - return ts; -} - -void measure(int fd) -{ - time_t start_time; - int last_state; - time_t last_time; - int curr_state; - time_t curr_time = 0; - time_t time_diff; - time_t active_time = 0; - time_t sleep_time = 0; - time_t unknown_time = 0; - time_t total_time = 0; - int changes = 0; - float tmp; - - printf("Starting measurements\n"); - - last_state = check_powermode(fd); - start_time = last_time = time(0); - printf(" System is in state %s\n\n", state_name(last_state)); - - while(!endit) { - sleep(1); - curr_state = check_powermode(fd); - - if (curr_state != last_state || endit) { - changes++; - curr_time = time(0); - time_diff = curr_time - last_time; - - if (last_state == 1) active_time += time_diff; - else if (last_state == 0) sleep_time += time_diff; - else unknown_time += time_diff; - - last_state = curr_state; - last_time = curr_time; - - printf("%s: State-change to %s\n", myctime(curr_time), - state_name(curr_state)); - } - } - changes--; /* Compensate for SIGINT */ - - total_time = time(0) - start_time; - printf("\nTotal running time: %lus\n", curr_time - start_time); - printf(" State changed %d times\n", changes); - - tmp = (float)sleep_time / (float)total_time * 100; - printf(" Time in sleep state: %lus (%.2f%%)\n", sleep_time, tmp); - tmp = (float)active_time / (float)total_time * 100; - printf(" Time in active state: %lus (%.2f%%)\n", active_time, tmp); - tmp = (float)unknown_time / (float)total_time * 100; - printf(" Time in unknown state: %lus (%.2f%%)\n", unknown_time, tmp); -} - -void ender(int s) -{ - endit = 1; -} - -void usage() -{ - puts("usage: dslm [-w <time>] <disk>"); - exit(0); -} - -int main(int argc, char **argv) -{ - int fd; - char *disk = 0; - int settle_time = 60; - - /* Parse the simple command-line */ - if (argc == 2) - disk = argv[1]; - else if (argc == 4) { - settle_time = atoi(argv[2]); - disk = argv[3]; - } else - usage(); - - if (!(fd = open(disk, O_RDONLY|O_NONBLOCK))) { - printf("Can't open %s, because: %s\n", disk, strerror(errno)); - exit(-1); - } - - if (settle_time) { - printf("Waiting %d seconds for the system to settle down to " - "'normal'\n", settle_time); - sleep(settle_time); - } else - puts("Not waiting for system to settle down"); - - signal(SIGINT, ender); - - measure(fd); - - close(fd); - - return 0; -} ----------------------------dslm.c END------------------------------------------- +spends spun up/down. See Documentation/laptops/dslm.c diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 7f5809eddee..631ad2f1b22 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -3,6 +3,7 @@ ============================ By: David Howells <dhowells@redhat.com> + Paul E. McKenney <paulmck@linux.vnet.ibm.com> Contents: @@ -60,6 +61,10 @@ Contents: - And then there's the Alpha. + (*) Example uses. + + - Circular buffers. + (*) References. @@ -2226,6 +2231,21 @@ The Alpha defines the Linux kernel's memory barrier model. See the subsection on "Cache Coherency" above. +============ +EXAMPLE USES +============ + +CIRCULAR BUFFERS +---------------- + +Memory barriers can be used to implement circular buffering without the need +of a lock to serialise the producer with the consumer. See: + + Documentation/circular-buffers.txt + +for details. + + ========== REFERENCES ========== diff --git a/Documentation/networking/Makefile b/Documentation/networking/Makefile index 6d8af1ac56c..5aba7a33aee 100644 --- a/Documentation/networking/Makefile +++ b/Documentation/networking/Makefile @@ -6,3 +6,5 @@ hostprogs-y := ifenslave # Tell kbuild to always build the programs always := $(hostprogs-y) + +obj-m := timestamping/ diff --git a/Documentation/networking/skfp.txt b/Documentation/networking/skfp.txt index abfddf81e34..203ec66c9fb 100644 --- a/Documentation/networking/skfp.txt +++ b/Documentation/networking/skfp.txt @@ -68,7 +68,7 @@ Compaq adapters (not tested): ======================= From v2.01 on, the driver is integrated in the linux kernel sources. -Therefor, the installation is the same as for any other adapter +Therefore, the installation is the same as for any other adapter supported by the kernel. Refer to the manual of your distribution about the installation of network adapters. diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt new file mode 100644 index 00000000000..7ee770b5ef5 --- /dev/null +++ b/Documentation/networking/stmmac.txt @@ -0,0 +1,143 @@ + STMicroelectronics 10/100/1000 Synopsys Ethernet driver + +Copyright (C) 2007-2010 STMicroelectronics Ltd +Author: Giuseppe Cavallaro <peppe.cavallaro@st.com> + +This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers +(Synopsys IP blocks); it has been fully tested on STLinux platforms. + +Currently this network device driver is for all STM embedded MAC/GMAC +(7xxx SoCs). + +DWC Ether MAC 10/100/1000 Universal version 3.41a and DWC Ether MAC 10/100 +Universal version 4.0 have been used for developing the first code +implementation. + +Please, for more information also visit: www.stlinux.com + +1) Kernel Configuration +The kernel configuration option is STMMAC_ETH: + Device Drivers ---> Network device support ---> Ethernet (1000 Mbit) ---> + STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH) + +2) Driver parameters list: + debug: message level (0: no output, 16: all); + phyaddr: to manually provide the physical address to the PHY device; + dma_rxsize: DMA rx ring size; + dma_txsize: DMA tx ring size; + buf_sz: DMA buffer size; + tc: control the HW FIFO threshold; + tx_coe: Enable/Disable Tx Checksum Offload engine; + watchdog: transmit timeout (in milliseconds); + flow_ctrl: Flow control ability [on/off]; + pause: Flow Control Pause Time; + tmrate: timer period (only if timer optimisation is configured). + +3) Command line options +Driver parameters can be also passed in command line by using: + stmmaceth=dma_rxsize:128,dma_txsize:512 + +4) Driver information and notes + +4.1) Transmit process +The xmit method is invoked when the kernel needs to transmit a packet; it sets +the descriptors in the ring and informs the DMA engine that there is a packet +ready to be transmitted. +Once the controller has finished transmitting the packet, an interrupt is +triggered; So the driver will be able to release the socket buffers. +By default, the driver sets the NETIF_F_SG bit in the features field of the +net_device structure enabling the scatter/gather feature. + +4.2) Receive process +When one or more packets are received, an interrupt happens. The interrupts +are not queued so the driver has to scan all the descriptors in the ring during +the receive process. +This is based on NAPI so the interrupt handler signals only if there is work to be +done, and it exits. +Then the poll method will be scheduled at some future point. +The incoming packets are stored, by the DMA, in a list of pre-allocated socket +buffers in order to avoid the memcpy (Zero-copy). + +4.3) Timer-Driver Interrupt +Instead of having the device that asynchronously notifies the frame receptions, the +driver configures a timer to generate an interrupt at regular intervals. +Based on the granularity of the timer, the frames that are received by the device +will experience different levels of latency. Some NICs have dedicated timer +device to perform this task. STMMAC can use either the RTC device or the TMU +channel 2 on STLinux platforms. +The timers frequency can be passed to the driver as parameter; when change it, +take care of both hardware capability and network stability/performance impact. +Several performance tests on STM platforms showed this optimisation allows to spare +the CPU while having the maximum throughput. + +4.4) WOL +Wake up on Lan feature through Magic Frame is only supported for the GMAC +core. + +4.5) DMA descriptors +Driver handles both normal and enhanced descriptors. The latter has been only +tested on DWC Ether MAC 10/100/1000 Universal version 3.41a. + +4.6) Ethtool support +Ethtool is supported. Driver statistics and internal errors can be taken using: +ethtool -S ethX command. It is possible to dump registers etc. + +4.7) Jumbo and Segmentation Offloading +Jumbo frames are supported and tested for the GMAC. +The GSO has been also added but it's performed in software. +LRO is not supported. + +4.8) Physical +The driver is compatible with PAL to work with PHY and GPHY devices. + +4.9) Platform information +Several information came from the platform; please refer to the +driver's Header file in include/linux directory. + +struct plat_stmmacenet_data { + int bus_id; + int pbl; + int has_gmac; + void (*fix_mac_speed)(void *priv, unsigned int speed); + void (*bus_setup)(unsigned long ioaddr); +#ifdef CONFIG_STM_DRIVERS + struct stm_pad_config *pad_config; +#endif + void *bsp_priv; +}; + +Where: +- pbl (Programmable Burst Length) is maximum number of + beats to be transferred in one DMA transaction. + GMAC also enables the 4xPBL by default. +- fix_mac_speed and bus_setup are used to configure internal target + registers (on STM platforms); +- has_gmac: GMAC core is on board (get it at run-time in the next step); +- bus_id: bus identifier. + +struct plat_stmmacphy_data { + int bus_id; + int phy_addr; + unsigned int phy_mask; + int interface; + int (*phy_reset)(void *priv); + void *priv; +}; + +Where: +- bus_id: bus identifier; +- phy_addr: physical address used for the attached phy device; + set it to -1 to get it at run-time; +- interface: physical MII interface mode; +- phy_reset: hook to reset HW function. + +TODO: +- Continue to make the driver more generic and suitable for other Synopsys + Ethernet controllers used on other architectures (i.e. ARM). +- 10G controllers are not supported. +- MAC uses Normal descriptors and GMAC uses enhanced ones. + This is a limit that should be reviewed. MAC could want to + use the enhanced structure. +- Checksumming: Rx/Tx csum is done in HW in case of GMAC only. +- Review the timer optimisation code to use an embedded device that seems to be + available in new chip generations. diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 0e58b453917..e8c8f4f06c6 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -41,11 +41,12 @@ SOF_TIMESTAMPING_SOFTWARE: return system time stamp generated in SOF_TIMESTAMPING_TX/RX determine how time stamps are generated. SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the following control message: - struct scm_timestamping { - struct timespec systime; - struct timespec hwtimetrans; - struct timespec hwtimeraw; - }; + +struct scm_timestamping { + struct timespec systime; + struct timespec hwtimetrans; + struct timespec hwtimeraw; +}; recvmsg() can be used to get this control message for regular incoming packets. For send time stamps the outgoing packet is looped back to @@ -87,12 +88,13 @@ by the network device and will be empty without that support. SIOCSHWTSTAMP: Hardware time stamping must also be initialized for each device driver -that is expected to do hardware time stamping. The parameter is: +that is expected to do hardware time stamping. The parameter is defined in +/include/linux/net_tstamp.h as: struct hwtstamp_config { - int flags; /* no flags defined right now, must be zero */ - int tx_type; /* HWTSTAMP_TX_* */ - int rx_filter; /* HWTSTAMP_FILTER_* */ + int flags; /* no flags defined right now, must be zero */ + int tx_type; /* HWTSTAMP_TX_* */ + int rx_filter; /* HWTSTAMP_FILTER_* */ }; Desired behavior is passed into the kernel and to a specific device by @@ -139,42 +141,56 @@ enum { /* time stamp any incoming packet */ HWTSTAMP_FILTER_ALL, - /* return value: time stamp all packets requested plus some others */ - HWTSTAMP_FILTER_SOME, + /* return value: time stamp all packets requested plus some others */ + HWTSTAMP_FILTER_SOME, /* PTP v1, UDP, any kind of event packet */ HWTSTAMP_FILTER_PTP_V1_L4_EVENT, - ... + /* for the complete list of values, please check + * the include file /include/linux/net_tstamp.h + */ }; DEVICE IMPLEMENTATION A driver which supports hardware time stamping must support the -SIOCSHWTSTAMP ioctl. Time stamps for received packets must be stored -in the skb with skb_hwtstamp_set(). +SIOCSHWTSTAMP ioctl and update the supplied struct hwtstamp_config with +the actual values as described in the section on SIOCSHWTSTAMP. + +Time stamps for received packets must be stored in the skb. To get a pointer +to the shared time stamp structure of the skb call skb_hwtstamps(). Then +set the time stamps in the structure: + +struct skb_shared_hwtstamps { + /* hardware time stamp transformed into duration + * since arbitrary point in time + */ + ktime_t hwtstamp; + ktime_t syststamp; /* hwtstamp transformed to system time base */ +}; Time stamps for outgoing packets are to be generated as follows: -- In hard_start_xmit(), check if skb_hwtstamp_check_tx_hardware() - returns non-zero. If yes, then the driver is expected - to do hardware time stamping. +- In hard_start_xmit(), check if skb_tx(skb)->hardware is set no-zero. + If yes, then the driver is expected to do hardware time stamping. - If this is possible for the skb and requested, then declare - that the driver is doing the time stamping by calling - skb_hwtstamp_tx_in_progress(). A driver not supporting - hardware time stamping doesn't do that. A driver must never - touch sk_buff::tstamp! It is used to store how time stamping - for an outgoing packets is to be done. + that the driver is doing the time stamping by setting the field + skb_tx(skb)->in_progress non-zero. You might want to keep a pointer + to the associated skb for the next step and not free the skb. A driver + not supporting hardware time stamping doesn't do that. A driver must + never touch sk_buff::tstamp! It is used to store software generated + time stamps by the network subsystem. - As soon as the driver has sent the packet and/or obtained a hardware time stamp for it, it passes the time stamp back by calling skb_hwtstamp_tx() with the original skb, the raw - hardware time stamp and a handle to the device (necessary - to convert the hardware time stamp to system time). If obtaining - the hardware time stamp somehow fails, then the driver should - not fall back to software time stamping. The rationale is that - this would occur at a later time in the processing pipeline - than other software time stamping and therefore could lead - to unexpected deltas between time stamps. -- If the driver did not call skb_hwtstamp_tx_in_progress(), then + hardware time stamp. skb_hwtstamp_tx() clones the original skb and + adds the timestamps, therefore the original skb has to be freed now. + If obtaining the hardware time stamp somehow fails, then the driver + should not fall back to software time stamping. The rationale is that + this would occur at a later time in the processing pipeline than other + software time stamping and therefore could lead to unexpected deltas + between time stamps. +- If the driver did not call set skb_tx(skb)->in_progress, then dev_hard_start_xmit() checks whether software time stamping is wanted as fallback and potentially generates the time stamp. diff --git a/Documentation/networking/timestamping/Makefile b/Documentation/networking/timestamping/Makefile index 2a1489fdc03..e79973443e9 100644 --- a/Documentation/networking/timestamping/Makefile +++ b/Documentation/networking/timestamping/Makefile @@ -1,6 +1,13 @@ -CPPFLAGS = -I../../../include +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o -timestamping: timestamping.c +# List of programs to build +hostprogs-y := timestamping + +# Tell kbuild to always build the programs +always := $(hostprogs-y) + +HOSTCFLAGS_timestamping.o += -I$(objtree)/usr/include clean: rm -f timestamping diff --git a/Documentation/networking/timestamping/timestamping.c b/Documentation/networking/timestamping/timestamping.c index a7936fe8444..8ba82bfe6a3 100644 --- a/Documentation/networking/timestamping/timestamping.c +++ b/Documentation/networking/timestamping/timestamping.c @@ -41,9 +41,9 @@ #include <arpa/inet.h> #include <net/if.h> -#include "asm/types.h" -#include "linux/net_tstamp.h" -#include "linux/errqueue.h" +#include <asm/types.h> +#include <linux/net_tstamp.h> +#include <linux/errqueue.h> #ifndef SO_TIMESTAMPING # define SO_TIMESTAMPING 37 @@ -164,7 +164,7 @@ static void printpacket(struct msghdr *msg, int res, gettimeofday(&now, 0); - printf("%ld.%06ld: received %s data, %d bytes from %s, %d bytes control messages\n", + printf("%ld.%06ld: received %s data, %d bytes from %s, %zu bytes control messages\n", (long)now.tv_sec, (long)now.tv_usec, (recvmsg_flags & MSG_ERRQUEUE) ? "error" : "regular", res, @@ -173,7 +173,7 @@ static void printpacket(struct msghdr *msg, int res, for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { - printf(" cmsg len %d: ", cmsg->cmsg_len); + printf(" cmsg len %zu: ", cmsg->cmsg_len); switch (cmsg->cmsg_level) { case SOL_SOCKET: printf("SOL_SOCKET "); @@ -370,7 +370,7 @@ int main(int argc, char **argv) } sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); - if (socket < 0) + if (sock < 0) bail("socket"); memset(&device, 0, sizeof(device)); diff --git a/Documentation/pnp.txt b/Documentation/pnp.txt index a327db67782..763e4659bf1 100644 --- a/Documentation/pnp.txt +++ b/Documentation/pnp.txt @@ -57,7 +57,7 @@ PC standard floppy disk controller # cat resources DISABLED -- Notice the string "DISABLED". THis means the device is not active. +- Notice the string "DISABLED". This means the device is not active. 3.) check the device's possible configurations (optional) # cat options @@ -139,7 +139,7 @@ Plug and Play but it is planned to be in the near future. Requirements for a Linux PnP protocol: 1.) the protocol must use EISA IDs -2.) the protocol must inform the PnP Layer of a devices current configuration +2.) the protocol must inform the PnP Layer of a device's current configuration - the ability to set resources is optional but preferred. The following are PnP protocol related functions: @@ -158,7 +158,7 @@ pnp_remove_device - automatically will free mem used by the device and related structures pnp_add_id -- adds a EISA ID to the list of supported IDs for the specified device +- adds an EISA ID to the list of supported IDs for the specified device For more information consult the source of a protocol such as /drivers/pnp/pnpbios/core.c. @@ -167,7 +167,7 @@ For more information consult the source of a protocol such as Linux Plug and Play Drivers --------------------------- - This section contains information for linux PnP driver developers. + This section contains information for Linux PnP driver developers. The New Way ........... @@ -235,11 +235,10 @@ static int __init serial8250_pnp_init(void) The Old Way ........... -a series of compatibility functions have been created to make it easy to convert - +A series of compatibility functions have been created to make it easy to convert ISAPNP drivers. They should serve as a temporary solution only. -they are as follows: +They are as follows: struct pnp_card *pnp_find_card(unsigned short vendor, unsigned short device, diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index ab00eeddeca..55b859b3bc7 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -256,7 +256,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: to suspend the device again in future int pm_runtime_resume(struct device *dev); - - execute the subsystem-leve resume callback for the device; returns 0 on + - execute the subsystem-level resume callback for the device; returns 0 on success, 1 if the device's run-time PM status was already 'active' or error code on failure, where -EAGAIN means it may be safe to attempt to resume the device again in future, but 'power.runtime_error' should be diff --git a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt index 6e37be1eeb2..4f8930263dd 100644 --- a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt +++ b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe.txt @@ -21,6 +21,15 @@ Required properties: - fsl,qe-num-snums: define how many serial number(SNUM) the QE can use for the threads. +Optional properties: +- fsl,firmware-phandle: + Usage: required only if there is no fsl,qe-firmware child node + Value type: <phandle> + Definition: Points to a firmware node (see "QE Firmware Node" below) + that contains the firmware that should be uploaded for this QE. + The compatible property for the firmware node should say, + "fsl,qe-firmware". + Recommended properties - brg-frequency : the internal clock source frequency for baud-rate generators in Hz. @@ -59,3 +68,48 @@ Example: reg = <0 c000>; }; }; + +* QE Firmware Node + +This node defines a firmware binary that is embedded in the device tree, for +the purpose of passing the firmware from bootloader to the kernel, or from +the hypervisor to the guest. + +The firmware node itself contains the firmware binary contents, a compatible +property, and any firmware-specific properties. The node should be placed +inside a QE node that needs it. Doing so eliminates the need for a +fsl,firmware-phandle property. Other QE nodes that need the same firmware +should define an fsl,firmware-phandle property that points to the firmware node +in the first QE node. + +The fsl,firmware property can be specified in the DTS (possibly using incbin) +or can be inserted by the boot loader at boot time. + +Required properties: + - compatible + Usage: required + Value type: <string> + Definition: A standard property. Specify a string that indicates what + kind of firmware it is. For QE, this should be "fsl,qe-firmware". + + - fsl,firmware + Usage: required + Value type: <prop-encoded-array>, encoded as an array of bytes + Definition: A standard property. This property contains the firmware + binary "blob". + +Example: + qe1@e0080000 { + compatible = "fsl,qe"; + qe_firmware:qe-firmware { + compatible = "fsl,qe-firmware"; + fsl,firmware = [0x70 0xcd 0x00 0x00 0x01 0x46 0x45 ...]; + }; + ... + }; + + qe2@e0090000 { + compatible = "fsl,qe"; + fsl,firmware-phandle = <&qe_firmware>; + ... + }; diff --git a/Documentation/s390/kvm.txt b/Documentation/s390/kvm.txt index 6f5ceb0f09f..85f3280d7ef 100644 --- a/Documentation/s390/kvm.txt +++ b/Documentation/s390/kvm.txt @@ -102,7 +102,7 @@ args: unsigned long see also: include/linux/kvm.h This ioctl stores the state of the cpu at the guest real address given as argument, unless one of the following values defined in include/linux/kvm.h -is given as arguement: +is given as argument: KVM_S390_STORE_STATUS_NOADDR - the CPU stores its status to the save area in absolute lowcore as defined by the principles of operation KVM_S390_STORE_STATUS_PREFIXED - the CPU stores its status to the save area in diff --git a/Documentation/scsi/ChangeLog.lpfc b/Documentation/scsi/ChangeLog.lpfc index ff19a52fe00..2ffc1148eb9 100644 --- a/Documentation/scsi/ChangeLog.lpfc +++ b/Documentation/scsi/ChangeLog.lpfc @@ -989,8 +989,8 @@ Changes from 20040709 to 20040716 * Remove redundant port_cmp != 2 check in if (!port_cmp) { .... if (port_cmp != 2).... } * Clock changes: removed struct clk_data and timerList. - * Clock changes: seperate nodev_tmo and els_retry_delay into 2 - seperate timers and convert to 1 argument changed + * Clock changes: separate nodev_tmo and els_retry_delay into 2 + separate timers and convert to 1 argument changed LPFC_NODE_FARP_PEND_t to struct lpfc_node_farp_pend convert ipfarp_tmo to 1 argument convert target struct tmofunc and rtplunfunc to 1 argument * cr_count, cr_delay and @@ -1514,7 +1514,7 @@ Changes from 20040402 to 20040409 * Remove unused elxclock declaration in elx_sli.h. * Since everywhere IOCB_ENTRY is used, the return value is cast, move the cast into the macro. - * Split ioctls out into seperate files + * Split ioctls out into separate files Changes from 20040326 to 20040402 @@ -1534,7 +1534,7 @@ Changes from 20040326 to 20040402 * Unused variable cleanup * Use Linux list macros for DMABUF_t * Break up ioctls into 3 sections, dfc, util, hbaapi - rearranged code so this could be easily seperated into a + rearranged code so this could be easily separated into a differnet module later All 3 are currently turned on by defines in lpfc_ioctl.c LPFC_DFC_IOCTL, LPFC_UTIL_IOCTL, LPFC_HBAAPI_IOCTL @@ -1551,7 +1551,7 @@ Changes from 20040326 to 20040402 started by lpfc_online(). lpfc_offline() only stopped els_timeout routine. It now stops all timeout routines associated with that hba. - * Replace seperate next and prev pointers in struct + * Replace separate next and prev pointers in struct lpfc_bindlist with list_head type. In elxHBA_t, replace fc_nlpbind_start and _end with fc_nlpbind_list and use list_head macros to access it. diff --git a/Documentation/serial/tty.txt b/Documentation/serial/tty.txt index 5e5349a4fcd..7c900507279 100644 --- a/Documentation/serial/tty.txt +++ b/Documentation/serial/tty.txt @@ -105,6 +105,10 @@ write_wakeup() - May be called at any point between open and close. is permitted to call the driver write method from this function. In such a situation defer it. +dcd_change() - Report to the tty line the current DCD pin status + changes and the relative timestamp. The timestamp + can be NULL. + Driver Access diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt index f4dd3bf99d1..98d14cb8a85 100644 --- a/Documentation/sound/alsa/HD-Audio.txt +++ b/Documentation/sound/alsa/HD-Audio.txt @@ -119,10 +119,18 @@ the codec slots 0 and 1 no matter what the hardware reports. Interrupt Handling ~~~~~~~~~~~~~~~~~~ -In rare but some cases, the interrupt isn't properly handled as -default. You would notice this by the DMA transfer error reported by -ALSA PCM core, for example. Using MSI might help in such a case. -Pass `enable_msi=1` option for enabling MSI. +HD-audio driver uses MSI as default (if available) since 2.6.33 +kernel as MSI works better on some machines, and in general, it's +better for performance. However, Nvidia controllers showed bad +regressions with MSI (especially in a combination with AMD chipset), +thus we disabled MSI for them. + +There seem also still other devices that don't work with MSI. If you +see a regression wrt the sound quality (stuttering, etc) or a lock-up +in the recent kernel, try to pass `enable_msi=0` option to disable +MSI. If it works, you can add the known bad device to the blacklist +defined in hda_intel.c. In such a case, please report and give the +patch back to the upstream developer. HD-AUDIO CODEC diff --git a/Documentation/spi/spidev_test.c b/Documentation/spi/spidev_test.c index 10abd3773e4..16feda90146 100644 --- a/Documentation/spi/spidev_test.c +++ b/Documentation/spi/spidev_test.c @@ -58,7 +58,7 @@ static void transfer(int fd) }; ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr); - if (ret == 1) + if (ret < 1) pabort("can't send spi message"); for (ret = 0; ret < ARRAY_SIZE(tx); ret++) { diff --git a/Documentation/stable_kernel_rules.txt b/Documentation/stable_kernel_rules.txt index 5effa5bd993..e213f45cf9d 100644 --- a/Documentation/stable_kernel_rules.txt +++ b/Documentation/stable_kernel_rules.txt @@ -18,16 +18,15 @@ Rules on what kind of patches are accepted, and which ones are not, into the - It cannot contain any "trivial" fixes in it (spelling changes, whitespace cleanups, etc). - It must follow the Documentation/SubmittingPatches rules. - - It or an equivalent fix must already exist in Linus' tree. Quote the - respective commit ID in Linus' tree in your patch submission to -stable. + - It or an equivalent fix must already exist in Linus' tree (upstream). Procedure for submitting patches to the -stable tree: - Send the patch, after verifying that it follows the above rules, to - stable@kernel.org. - - To have the patch automatically included in the stable tree, add the - the tag + stable@kernel.org. You must note the upstream commit ID in the changelog + of your submission. + - To have the patch automatically included in the stable tree, add the tag Cc: stable@kernel.org in the sign-off area. Once the patch is merged it will be applied to the stable tree without anything else needing to be done by the author diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index fc5790d36cd..6c7d18c53f8 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -573,11 +573,14 @@ Because other nodes' memory may be free. This means system total status may be not fatal yet. If this is set to 2, the kernel panics compulsorily even on the -above-mentioned. +above-mentioned. Even oom happens under memory cgroup, the whole +system panics. The default value is 0. 1 and 2 are for failover of clustering. Please select either according to your policy of failover. +panic_on_oom=2+kdump gives you very strong tool to investigate +why oom happens. You can get snapshot. ============================================================= diff --git a/Documentation/timers/00-INDEX b/Documentation/timers/00-INDEX index 397dc35e132..a9248da5cdb 100644 --- a/Documentation/timers/00-INDEX +++ b/Documentation/timers/00-INDEX @@ -4,6 +4,8 @@ highres.txt - High resolution timers and dynamic ticks design notes hpet.txt - High Precision Event Timer Driver for Linux +hpet_example.c + - sample hpet timer test program hrtimers.txt - subsystem for high-resolution kernel timers timer_stats.txt diff --git a/Documentation/timers/Makefile b/Documentation/timers/Makefile new file mode 100644 index 00000000000..c85625f4ab2 --- /dev/null +++ b/Documentation/timers/Makefile @@ -0,0 +1,8 @@ +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o + +# List of programs to build +hostprogs-y := hpet_example + +# Tell kbuild to always build the programs +always := $(hostprogs-y) diff --git a/Documentation/timers/hpet.txt b/Documentation/timers/hpet.txt index 16d25e6b5a0..767392ffd31 100644 --- a/Documentation/timers/hpet.txt +++ b/Documentation/timers/hpet.txt @@ -26,274 +26,5 @@ initialization. An example of this initialization can be found in arch/x86/kernel/hpet.c. The driver provides a userspace API which resembles the API found in the -RTC driver framework. An example user space program is provided below. - -#include <stdio.h> -#include <stdlib.h> -#include <unistd.h> -#include <fcntl.h> -#include <string.h> -#include <memory.h> -#include <malloc.h> -#include <time.h> -#include <ctype.h> -#include <sys/types.h> -#include <sys/wait.h> -#include <signal.h> -#include <fcntl.h> -#include <errno.h> -#include <sys/time.h> -#include <linux/hpet.h> - - -extern void hpet_open_close(int, const char **); -extern void hpet_info(int, const char **); -extern void hpet_poll(int, const char **); -extern void hpet_fasync(int, const char **); -extern void hpet_read(int, const char **); - -#include <sys/poll.h> -#include <sys/ioctl.h> -#include <signal.h> - -struct hpet_command { - char *command; - void (*func)(int argc, const char ** argv); -} hpet_command[] = { - { - "open-close", - hpet_open_close - }, - { - "info", - hpet_info - }, - { - "poll", - hpet_poll - }, - { - "fasync", - hpet_fasync - }, -}; - -int -main(int argc, const char ** argv) -{ - int i; - - argc--; - argv++; - - if (!argc) { - fprintf(stderr, "-hpet: requires command\n"); - return -1; - } - - - for (i = 0; i < (sizeof (hpet_command) / sizeof (hpet_command[0])); i++) - if (!strcmp(argv[0], hpet_command[i].command)) { - argc--; - argv++; - fprintf(stderr, "-hpet: executing %s\n", - hpet_command[i].command); - hpet_command[i].func(argc, argv); - return 0; - } - - fprintf(stderr, "do_hpet: command %s not implemented\n", argv[0]); - - return -1; -} - -void -hpet_open_close(int argc, const char **argv) -{ - int fd; - - if (argc != 1) { - fprintf(stderr, "hpet_open_close: device-name\n"); - return; - } - - fd = open(argv[0], O_RDONLY); - if (fd < 0) - fprintf(stderr, "hpet_open_close: open failed\n"); - else - close(fd); - - return; -} - -void -hpet_info(int argc, const char **argv) -{ -} - -void -hpet_poll(int argc, const char **argv) -{ - unsigned long freq; - int iterations, i, fd; - struct pollfd pfd; - struct hpet_info info; - struct timeval stv, etv; - struct timezone tz; - long usec; - - if (argc != 3) { - fprintf(stderr, "hpet_poll: device-name freq iterations\n"); - return; - } - - freq = atoi(argv[1]); - iterations = atoi(argv[2]); - - fd = open(argv[0], O_RDONLY); - - if (fd < 0) { - fprintf(stderr, "hpet_poll: open of %s failed\n", argv[0]); - return; - } - - if (ioctl(fd, HPET_IRQFREQ, freq) < 0) { - fprintf(stderr, "hpet_poll: HPET_IRQFREQ failed\n"); - goto out; - } - - if (ioctl(fd, HPET_INFO, &info) < 0) { - fprintf(stderr, "hpet_poll: failed to get info\n"); - goto out; - } - - fprintf(stderr, "hpet_poll: info.hi_flags 0x%lx\n", info.hi_flags); - - if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) { - fprintf(stderr, "hpet_poll: HPET_EPI failed\n"); - goto out; - } - - if (ioctl(fd, HPET_IE_ON, 0) < 0) { - fprintf(stderr, "hpet_poll, HPET_IE_ON failed\n"); - goto out; - } - - pfd.fd = fd; - pfd.events = POLLIN; - - for (i = 0; i < iterations; i++) { - pfd.revents = 0; - gettimeofday(&stv, &tz); - if (poll(&pfd, 1, -1) < 0) - fprintf(stderr, "hpet_poll: poll failed\n"); - else { - long data; - - gettimeofday(&etv, &tz); - usec = stv.tv_sec * 1000000 + stv.tv_usec; - usec = (etv.tv_sec * 1000000 + etv.tv_usec) - usec; - - fprintf(stderr, - "hpet_poll: expired time = 0x%lx\n", usec); - - fprintf(stderr, "hpet_poll: revents = 0x%x\n", - pfd.revents); - - if (read(fd, &data, sizeof(data)) != sizeof(data)) { - fprintf(stderr, "hpet_poll: read failed\n"); - } - else - fprintf(stderr, "hpet_poll: data 0x%lx\n", - data); - } - } - -out: - close(fd); - return; -} - -static int hpet_sigio_count; - -static void -hpet_sigio(int val) -{ - fprintf(stderr, "hpet_sigio: called\n"); - hpet_sigio_count++; -} - -void -hpet_fasync(int argc, const char **argv) -{ - unsigned long freq; - int iterations, i, fd, value; - sig_t oldsig; - struct hpet_info info; - - hpet_sigio_count = 0; - fd = -1; - - if ((oldsig = signal(SIGIO, hpet_sigio)) == SIG_ERR) { - fprintf(stderr, "hpet_fasync: failed to set signal handler\n"); - return; - } - - if (argc != 3) { - fprintf(stderr, "hpet_fasync: device-name freq iterations\n"); - goto out; - } - - fd = open(argv[0], O_RDONLY); - - if (fd < 0) { - fprintf(stderr, "hpet_fasync: failed to open %s\n", argv[0]); - return; - } - - - if ((fcntl(fd, F_SETOWN, getpid()) == 1) || - ((value = fcntl(fd, F_GETFL)) == 1) || - (fcntl(fd, F_SETFL, value | O_ASYNC) == 1)) { - fprintf(stderr, "hpet_fasync: fcntl failed\n"); - goto out; - } - - freq = atoi(argv[1]); - iterations = atoi(argv[2]); - - if (ioctl(fd, HPET_IRQFREQ, freq) < 0) { - fprintf(stderr, "hpet_fasync: HPET_IRQFREQ failed\n"); - goto out; - } - - if (ioctl(fd, HPET_INFO, &info) < 0) { - fprintf(stderr, "hpet_fasync: failed to get info\n"); - goto out; - } - - fprintf(stderr, "hpet_fasync: info.hi_flags 0x%lx\n", info.hi_flags); - - if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) { - fprintf(stderr, "hpet_fasync: HPET_EPI failed\n"); - goto out; - } - - if (ioctl(fd, HPET_IE_ON, 0) < 0) { - fprintf(stderr, "hpet_fasync, HPET_IE_ON failed\n"); - goto out; - } - - for (i = 0; i < iterations; i++) { - (void) pause(); - fprintf(stderr, "hpet_fasync: count = %d\n", hpet_sigio_count); - } - -out: - signal(SIGIO, oldsig); - - if (fd >= 0) - close(fd); - - return; -} +RTC driver framework. An example user space program is provided in +file:Documentation/timers/hpet_example.c diff --git a/Documentation/timers/hpet_example.c b/Documentation/timers/hpet_example.c new file mode 100644 index 00000000000..f9ce2d9fdfd --- /dev/null +++ b/Documentation/timers/hpet_example.c @@ -0,0 +1,269 @@ +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <fcntl.h> +#include <string.h> +#include <memory.h> +#include <malloc.h> +#include <time.h> +#include <ctype.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <signal.h> +#include <fcntl.h> +#include <errno.h> +#include <sys/time.h> +#include <linux/hpet.h> + + +extern void hpet_open_close(int, const char **); +extern void hpet_info(int, const char **); +extern void hpet_poll(int, const char **); +extern void hpet_fasync(int, const char **); +extern void hpet_read(int, const char **); + +#include <sys/poll.h> +#include <sys/ioctl.h> +#include <signal.h> + +struct hpet_command { + char *command; + void (*func)(int argc, const char ** argv); +} hpet_command[] = { + { + "open-close", + hpet_open_close + }, + { + "info", + hpet_info + }, + { + "poll", + hpet_poll + }, + { + "fasync", + hpet_fasync + }, +}; + +int +main(int argc, const char ** argv) +{ + int i; + + argc--; + argv++; + + if (!argc) { + fprintf(stderr, "-hpet: requires command\n"); + return -1; + } + + + for (i = 0; i < (sizeof (hpet_command) / sizeof (hpet_command[0])); i++) + if (!strcmp(argv[0], hpet_command[i].command)) { + argc--; + argv++; + fprintf(stderr, "-hpet: executing %s\n", + hpet_command[i].command); + hpet_command[i].func(argc, argv); + return 0; + } + + fprintf(stderr, "do_hpet: command %s not implemented\n", argv[0]); + + return -1; +} + +void +hpet_open_close(int argc, const char **argv) +{ + int fd; + + if (argc != 1) { + fprintf(stderr, "hpet_open_close: device-name\n"); + return; + } + + fd = open(argv[0], O_RDONLY); + if (fd < 0) + fprintf(stderr, "hpet_open_close: open failed\n"); + else + close(fd); + + return; +} + +void +hpet_info(int argc, const char **argv) +{ +} + +void +hpet_poll(int argc, const char **argv) +{ + unsigned long freq; + int iterations, i, fd; + struct pollfd pfd; + struct hpet_info info; + struct timeval stv, etv; + struct timezone tz; + long usec; + + if (argc != 3) { + fprintf(stderr, "hpet_poll: device-name freq iterations\n"); + return; + } + + freq = atoi(argv[1]); + iterations = atoi(argv[2]); + + fd = open(argv[0], O_RDONLY); + + if (fd < 0) { + fprintf(stderr, "hpet_poll: open of %s failed\n", argv[0]); + return; + } + + if (ioctl(fd, HPET_IRQFREQ, freq) < 0) { + fprintf(stderr, "hpet_poll: HPET_IRQFREQ failed\n"); + goto out; + } + + if (ioctl(fd, HPET_INFO, &info) < 0) { + fprintf(stderr, "hpet_poll: failed to get info\n"); + goto out; + } + + fprintf(stderr, "hpet_poll: info.hi_flags 0x%lx\n", info.hi_flags); + + if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) { + fprintf(stderr, "hpet_poll: HPET_EPI failed\n"); + goto out; + } + + if (ioctl(fd, HPET_IE_ON, 0) < 0) { + fprintf(stderr, "hpet_poll, HPET_IE_ON failed\n"); + goto out; + } + + pfd.fd = fd; + pfd.events = POLLIN; + + for (i = 0; i < iterations; i++) { + pfd.revents = 0; + gettimeofday(&stv, &tz); + if (poll(&pfd, 1, -1) < 0) + fprintf(stderr, "hpet_poll: poll failed\n"); + else { + long data; + + gettimeofday(&etv, &tz); + usec = stv.tv_sec * 1000000 + stv.tv_usec; + usec = (etv.tv_sec * 1000000 + etv.tv_usec) - usec; + + fprintf(stderr, + "hpet_poll: expired time = 0x%lx\n", usec); + + fprintf(stderr, "hpet_poll: revents = 0x%x\n", + pfd.revents); + + if (read(fd, &data, sizeof(data)) != sizeof(data)) { + fprintf(stderr, "hpet_poll: read failed\n"); + } + else + fprintf(stderr, "hpet_poll: data 0x%lx\n", + data); + } + } + +out: + close(fd); + return; +} + +static int hpet_sigio_count; + +static void +hpet_sigio(int val) +{ + fprintf(stderr, "hpet_sigio: called\n"); + hpet_sigio_count++; +} + +void +hpet_fasync(int argc, const char **argv) +{ + unsigned long freq; + int iterations, i, fd, value; + sig_t oldsig; + struct hpet_info info; + + hpet_sigio_count = 0; + fd = -1; + + if ((oldsig = signal(SIGIO, hpet_sigio)) == SIG_ERR) { + fprintf(stderr, "hpet_fasync: failed to set signal handler\n"); + return; + } + + if (argc != 3) { + fprintf(stderr, "hpet_fasync: device-name freq iterations\n"); + goto out; + } + + fd = open(argv[0], O_RDONLY); + + if (fd < 0) { + fprintf(stderr, "hpet_fasync: failed to open %s\n", argv[0]); + return; + } + + + if ((fcntl(fd, F_SETOWN, getpid()) == 1) || + ((value = fcntl(fd, F_GETFL)) == 1) || + (fcntl(fd, F_SETFL, value | O_ASYNC) == 1)) { + fprintf(stderr, "hpet_fasync: fcntl failed\n"); + goto out; + } + + freq = atoi(argv[1]); + iterations = atoi(argv[2]); + + if (ioctl(fd, HPET_IRQFREQ, freq) < 0) { + fprintf(stderr, "hpet_fasync: HPET_IRQFREQ failed\n"); + goto out; + } + + if (ioctl(fd, HPET_INFO, &info) < 0) { + fprintf(stderr, "hpet_fasync: failed to get info\n"); + goto out; + } + + fprintf(stderr, "hpet_fasync: info.hi_flags 0x%lx\n", info.hi_flags); + + if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) { + fprintf(stderr, "hpet_fasync: HPET_EPI failed\n"); + goto out; + } + + if (ioctl(fd, HPET_IE_ON, 0) < 0) { + fprintf(stderr, "hpet_fasync, HPET_IE_ON failed\n"); + goto out; + } + + for (i = 0; i < iterations; i++) { + (void) pause(); + fprintf(stderr, "hpet_fasync: count = %d\n", hpet_sigio_count); + } + +out: + signal(SIGIO, oldsig); + + if (fd >= 0) + close(fd); + + return; +} diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index bab3040da54..03485bfbd79 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -1588,7 +1588,7 @@ module author does not need to worry about it. When tracing is enabled, kstop_machine is called to prevent races with the CPUS executing code being modified (which can -cause the CPU to do undesireable things), and the nops are +cause the CPU to do undesirable things), and the nops are patched back to calls. But this time, they do not call mcount (which is just a function stub). They now call into the ftrace infrastructure. diff --git a/Documentation/vm/00-INDEX b/Documentation/vm/00-INDEX index e57d6a9dd32..dca82d7c83d 100644 --- a/Documentation/vm/00-INDEX +++ b/Documentation/vm/00-INDEX @@ -4,23 +4,35 @@ active_mm.txt - An explanation from Linus about tsk->active_mm vs tsk->mm. balance - various information on memory balancing. +hugepage-mmap.c + - Example app using huge page memory with the mmap system call. +hugepage-shm.c + - Example app using huge page memory with Sys V shared memory system calls. hugetlbpage.txt - a brief summary of hugetlbpage support in the Linux kernel. +hwpoison.txt + - explains what hwpoison is ksm.txt - how to use the Kernel Samepage Merging feature. locking - info on how locking and synchronization is done in the Linux vm code. +map_hugetlb.c + - an example program that uses the MAP_HUGETLB mmap flag. numa - information about NUMA specific code in the Linux vm. numa_memory_policy.txt - documentation of concepts and APIs of the 2.6 memory policy support. overcommit-accounting - description of the Linux kernels overcommit handling modes. +page-types.c + - Tool for querying page flags page_migration - description of page migration in NUMA systems. +pagemap.txt + - pagemap, from the userspace perspective slabinfo.c - source code for a tool to get reports about slabs. slub.txt - a short users guide for SLUB. -map_hugetlb.c - - an example program that uses the MAP_HUGETLB mmap flag. +unevictable-lru.txt + - Unevictable LRU infrastructure diff --git a/Documentation/vm/Makefile b/Documentation/vm/Makefile index 5bd269b3731..9dcff328b96 100644 --- a/Documentation/vm/Makefile +++ b/Documentation/vm/Makefile @@ -2,7 +2,7 @@ obj- := dummy.o # List of programs to build -hostprogs-y := slabinfo page-types +hostprogs-y := slabinfo page-types hugepage-mmap hugepage-shm map_hugetlb # Tell kbuild to always build the programs always := $(hostprogs-y) diff --git a/Documentation/vm/hugepage-mmap.c b/Documentation/vm/hugepage-mmap.c new file mode 100644 index 00000000000..db0dd9a33d5 --- /dev/null +++ b/Documentation/vm/hugepage-mmap.c @@ -0,0 +1,91 @@ +/* + * hugepage-mmap: + * + * Example of using huge page memory in a user application using the mmap + * system call. Before running this application, make sure that the + * administrator has mounted the hugetlbfs filesystem (on some directory + * like /mnt) using the command mount -t hugetlbfs nodev /mnt. In this + * example, the app is requesting memory of size 256MB that is backed by + * huge pages. + * + * For the ia64 architecture, the Linux kernel reserves Region number 4 for + * huge pages. That means that if one requires a fixed address, a huge page + * aligned address starting with 0x800000... will be required. If a fixed + * address is not required, the kernel will select an address in the proper + * range. + * Other architectures, such as ppc64, i386 or x86_64 are not so constrained. + */ + +#include <stdlib.h> +#include <stdio.h> +#include <unistd.h> +#include <sys/mman.h> +#include <fcntl.h> + +#define FILE_NAME "/mnt/hugepagefile" +#define LENGTH (256UL*1024*1024) +#define PROTECTION (PROT_READ | PROT_WRITE) + +/* Only ia64 requires this */ +#ifdef __ia64__ +#define ADDR (void *)(0x8000000000000000UL) +#define FLAGS (MAP_SHARED | MAP_FIXED) +#else +#define ADDR (void *)(0x0UL) +#define FLAGS (MAP_SHARED) +#endif + +static void check_bytes(char *addr) +{ + printf("First hex is %x\n", *((unsigned int *)addr)); +} + +static void write_bytes(char *addr) +{ + unsigned long i; + + for (i = 0; i < LENGTH; i++) + *(addr + i) = (char)i; +} + +static void read_bytes(char *addr) +{ + unsigned long i; + + check_bytes(addr); + for (i = 0; i < LENGTH; i++) + if (*(addr + i) != (char)i) { + printf("Mismatch at %lu\n", i); + break; + } +} + +int main(void) +{ + void *addr; + int fd; + + fd = open(FILE_NAME, O_CREAT | O_RDWR, 0755); + if (fd < 0) { + perror("Open failed"); + exit(1); + } + + addr = mmap(ADDR, LENGTH, PROTECTION, FLAGS, fd, 0); + if (addr == MAP_FAILED) { + perror("mmap"); + unlink(FILE_NAME); + exit(1); + } + + printf("Returned address is %p\n", addr); + check_bytes(addr); + write_bytes(addr); + read_bytes(addr); + + munmap(addr, LENGTH); + close(fd); + unlink(FILE_NAME); + + return 0; +} diff --git a/Documentation/vm/hugepage-shm.c b/Documentation/vm/hugepage-shm.c new file mode 100644 index 00000000000..07956d8592c --- /dev/null +++ b/Documentation/vm/hugepage-shm.c @@ -0,0 +1,98 @@ +/* + * hugepage-shm: + * + * Example of using huge page memory in a user application using Sys V shared + * memory system calls. In this example the app is requesting 256MB of + * memory that is backed by huge pages. The application uses the flag + * SHM_HUGETLB in the shmget system call to inform the kernel that it is + * requesting huge pages. + * + * For the ia64 architecture, the Linux kernel reserves Region number 4 for + * huge pages. That means that if one requires a fixed address, a huge page + * aligned address starting with 0x800000... will be required. If a fixed + * address is not required, the kernel will select an address in the proper + * range. + * Other architectures, such as ppc64, i386 or x86_64 are not so constrained. + * + * Note: The default shared memory limit is quite low on many kernels, + * you may need to increase it via: + * + * echo 268435456 > /proc/sys/kernel/shmmax + * + * This will increase the maximum size per shared memory segment to 256MB. + * The other limit that you will hit eventually is shmall which is the + * total amount of shared memory in pages. To set it to 16GB on a system + * with a 4kB pagesize do: + * + * echo 4194304 > /proc/sys/kernel/shmall + */ + +#include <stdlib.h> +#include <stdio.h> +#include <sys/types.h> +#include <sys/ipc.h> +#include <sys/shm.h> +#include <sys/mman.h> + +#ifndef SHM_HUGETLB +#define SHM_HUGETLB 04000 +#endif + +#define LENGTH (256UL*1024*1024) + +#define dprintf(x) printf(x) + +/* Only ia64 requires this */ +#ifdef __ia64__ +#define ADDR (void *)(0x8000000000000000UL) +#define SHMAT_FLAGS (SHM_RND) +#else +#define ADDR (void *)(0x0UL) +#define SHMAT_FLAGS (0) +#endif + +int main(void) +{ + int shmid; + unsigned long i; + char *shmaddr; + + if ((shmid = shmget(2, LENGTH, + SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W)) < 0) { + perror("shmget"); + exit(1); + } + printf("shmid: 0x%x\n", shmid); + + shmaddr = shmat(shmid, ADDR, SHMAT_FLAGS); + if (shmaddr == (char *)-1) { + perror("Shared memory attach failure"); + shmctl(shmid, IPC_RMID, NULL); + exit(2); + } + printf("shmaddr: %p\n", shmaddr); + + dprintf("Starting the writes:\n"); + for (i = 0; i < LENGTH; i++) { + shmaddr[i] = (char)(i); + if (!(i % (1024 * 1024))) + dprintf("."); + } + dprintf("\n"); + + dprintf("Starting the Check..."); + for (i = 0; i < LENGTH; i++) + if (shmaddr[i] != (char)i) + printf("\nIndex %lu mismatched\n", i); + dprintf("Done.\n"); + + if (shmdt((const void *)shmaddr) != 0) { + perror("Detach failure"); + shmctl(shmid, IPC_RMID, NULL); + exit(3); + } + + shmctl(shmid, IPC_RMID, NULL); + + return 0; +} diff --git a/Documentation/vm/hugetlbpage.txt b/Documentation/vm/hugetlbpage.txt index bc31636973e..457634c1e03 100644 --- a/Documentation/vm/hugetlbpage.txt +++ b/Documentation/vm/hugetlbpage.txt @@ -299,176 +299,11 @@ map_hugetlb.c. ******************************************************************* /* - * Example of using huge page memory in a user application using Sys V shared - * memory system calls. In this example the app is requesting 256MB of - * memory that is backed by huge pages. The application uses the flag - * SHM_HUGETLB in the shmget system call to inform the kernel that it is - * requesting huge pages. - * - * For the ia64 architecture, the Linux kernel reserves Region number 4 for - * huge pages. That means that if one requires a fixed address, a huge page - * aligned address starting with 0x800000... will be required. If a fixed - * address is not required, the kernel will select an address in the proper - * range. - * Other architectures, such as ppc64, i386 or x86_64 are not so constrained. - * - * Note: The default shared memory limit is quite low on many kernels, - * you may need to increase it via: - * - * echo 268435456 > /proc/sys/kernel/shmmax - * - * This will increase the maximum size per shared memory segment to 256MB. - * The other limit that you will hit eventually is shmall which is the - * total amount of shared memory in pages. To set it to 16GB on a system - * with a 4kB pagesize do: - * - * echo 4194304 > /proc/sys/kernel/shmall + * hugepage-shm: see Documentation/vm/hugepage-shm.c */ -#include <stdlib.h> -#include <stdio.h> -#include <sys/types.h> -#include <sys/ipc.h> -#include <sys/shm.h> -#include <sys/mman.h> - -#ifndef SHM_HUGETLB -#define SHM_HUGETLB 04000 -#endif - -#define LENGTH (256UL*1024*1024) - -#define dprintf(x) printf(x) - -#define ADDR (void *)(0x0UL) /* let kernel choose address */ -#define SHMAT_FLAGS (0) - -int main(void) -{ - int shmid; - unsigned long i; - char *shmaddr; - - if ((shmid = shmget(2, LENGTH, - SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W)) < 0) { - perror("shmget"); - exit(1); - } - printf("shmid: 0x%x\n", shmid); - - shmaddr = shmat(shmid, ADDR, SHMAT_FLAGS); - if (shmaddr == (char *)-1) { - perror("Shared memory attach failure"); - shmctl(shmid, IPC_RMID, NULL); - exit(2); - } - printf("shmaddr: %p\n", shmaddr); - - dprintf("Starting the writes:\n"); - for (i = 0; i < LENGTH; i++) { - shmaddr[i] = (char)(i); - if (!(i % (1024 * 1024))) - dprintf("."); - } - dprintf("\n"); - - dprintf("Starting the Check..."); - for (i = 0; i < LENGTH; i++) - if (shmaddr[i] != (char)i) - printf("\nIndex %lu mismatched\n", i); - dprintf("Done.\n"); - - if (shmdt((const void *)shmaddr) != 0) { - perror("Detach failure"); - shmctl(shmid, IPC_RMID, NULL); - exit(3); - } - - shmctl(shmid, IPC_RMID, NULL); - - return 0; -} ******************************************************************* /* - * Example of using huge page memory in a user application using the mmap - * system call. Before running this application, make sure that the - * administrator has mounted the hugetlbfs filesystem (on some directory - * like /mnt) using the command mount -t hugetlbfs nodev /mnt. In this - * example, the app is requesting memory of size 256MB that is backed by - * huge pages. - * - * For the ia64 architecture, the Linux kernel reserves Region number 4 for - * huge pages. That means that if one requires a fixed address, a huge page - * aligned address starting with 0x800000... will be required. If a fixed - * address is not required, the kernel will select an address in the proper - * range. - * Other architectures, such as ppc64, i386 or x86_64 are not so constrained. + * hugepage-mmap: see Documentation/vm/hugepage-mmap.c */ -#include <stdlib.h> -#include <stdio.h> -#include <unistd.h> -#include <sys/mman.h> -#include <fcntl.h> - -#define FILE_NAME "/mnt/hugepagefile" -#define LENGTH (256UL*1024*1024) -#define PROTECTION (PROT_READ | PROT_WRITE) - -#define ADDR (void *)(0x0UL) /* let kernel choose address */ -#define FLAGS (MAP_SHARED) - -void check_bytes(char *addr) -{ - printf("First hex is %x\n", *((unsigned int *)addr)); -} - -void write_bytes(char *addr) -{ - unsigned long i; - - for (i = 0; i < LENGTH; i++) - *(addr + i) = (char)i; -} - -void read_bytes(char *addr) -{ - unsigned long i; - - check_bytes(addr); - for (i = 0; i < LENGTH; i++) - if (*(addr + i) != (char)i) { - printf("Mismatch at %lu\n", i); - break; - } -} - -int main(void) -{ - void *addr; - int fd; - - fd = open(FILE_NAME, O_CREAT | O_RDWR, 0755); - if (fd < 0) { - perror("Open failed"); - exit(1); - } - - addr = mmap(ADDR, LENGTH, PROTECTION, FLAGS, fd, 0); - if (addr == MAP_FAILED) { - perror("mmap"); - unlink(FILE_NAME); - exit(1); - } - - printf("Returned address is %p\n", addr); - check_bytes(addr); - write_bytes(addr); - read_bytes(addr); - - munmap(addr, LENGTH); - close(fd); - unlink(FILE_NAME); - - return 0; -} diff --git a/Documentation/vm/map_hugetlb.c b/Documentation/vm/map_hugetlb.c index e2bdae37f49..9969c7d9f98 100644 --- a/Documentation/vm/map_hugetlb.c +++ b/Documentation/vm/map_hugetlb.c @@ -31,12 +31,12 @@ #define FLAGS (MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB) #endif -void check_bytes(char *addr) +static void check_bytes(char *addr) { printf("First hex is %x\n", *((unsigned int *)addr)); } -void write_bytes(char *addr) +static void write_bytes(char *addr) { unsigned long i; @@ -44,7 +44,7 @@ void write_bytes(char *addr) *(addr + i) = (char)i; } -void read_bytes(char *addr) +static void read_bytes(char *addr) { unsigned long i; diff --git a/Documentation/volatile-considered-harmful.txt b/Documentation/volatile-considered-harmful.txt index 991c26a6ef6..db0cb228d64 100644 --- a/Documentation/volatile-considered-harmful.txt +++ b/Documentation/volatile-considered-harmful.txt @@ -63,9 +63,9 @@ way to perform a busy wait is: cpu_relax(); The cpu_relax() call can lower CPU power consumption or yield to a -hyperthreaded twin processor; it also happens to serve as a memory barrier, -so, once again, volatile is unnecessary. Of course, busy-waiting is -generally an anti-social act to begin with. +hyperthreaded twin processor; it also happens to serve as a compiler +barrier, so, once again, volatile is unnecessary. Of course, busy- +waiting is generally an anti-social act to begin with. There are still a few rare situations where volatile makes sense in the kernel: diff --git a/Documentation/voyager.txt b/Documentation/voyager.txt deleted file mode 100644 index 2749af552cd..00000000000 --- a/Documentation/voyager.txt +++ /dev/null @@ -1,95 +0,0 @@ -Running Linux on the Voyager Architecture -========================================= - -For full details and current project status, see - -http://www.hansenpartnership.com/voyager - -The voyager architecture was designed by NCR in the mid 80s to be a -fully SMP capable RAS computing architecture built around intel's 486 -chip set. The voyager came in three levels of architectural -sophistication: 3,4 and 5 --- 1 and 2 never made it out of prototype. -The linux patches support only the Level 5 voyager architecture (any -machine class 3435 and above). - -The Voyager Architecture ------------------------- - -Voyager machines consist of a Baseboard with a 386 diagnostic -processor, a Power Supply Interface (PSI) a Primary and possibly -Secondary Microchannel bus and between 2 and 20 voyager slots. The -voyager slots can be populated with memory and cpu cards (up to 4GB -memory and from 1 486 to 32 Pentium Pro processors). Internally, the -voyager has a dual arbitrated system bus and a configuration and test -bus (CAT). The voyager bus speed is 40MHz. Therefore (since all -voyager cards are dual ported for each system bus) the maximum -transfer rate is 320Mb/s but only if you have your slot configuration -tuned (only memory cards can communicate with both busses at once, CPU -cards utilise them one at a time). - -Voyager SMP ------------ - -Since voyager was the first intel based SMP system, it is slightly -more primitive than the Intel IO-APIC approach to SMP. Voyager allows -arbitrary interrupt routing (including processor affinity routing) of -all 16 PC type interrupts. However it does this by using a modified -5259 master/slave chip set instead of an APIC bus. Additionally, -voyager supports Cross Processor Interrupts (CPI) equivalent to the -APIC IPIs. There are two routed voyager interrupt lines provided to -each slot. - -Processor Cards ---------------- - -These come in single, dyadic and quad configurations (the quads are -problematic--see later). The maximum configuration is 8 quad cards -for 32 way SMP. - -Quad Processors ---------------- - -Because voyager only supplies two interrupt lines to each Processor -card, the Quad processors have to be configured (and Bootstrapped) in -as a pair of Master/Slave processors. - -In fact, most Quad cards only accept one VIC interrupt line, so they -have one interrupt handling processor (called the VIC extended -processor) and three non-interrupt handling processors. - -Current Status --------------- - -The System will boot on Mono, Dyad and Quad cards. There was -originally a Quad boot problem which has been fixed by proper gdt -alignment in the initial boot loader. If you still cannot get your -voyager system to boot, email me at: - -<J.E.J.Bottomley@HansenPartnership.com> - - -The Quad cards now support using the separate Quad CPI vectors instead -of going through the VIC mailbox system. - -The Level 4 architecture (3430 and 3360 Machines) should also work -fine. - -Dump Switch ------------ - -The voyager dump switch sends out a broadcast NMI which the voyager -code intercepts and does a task dump. - -Power Switch ------------- - -The front panel power switch is intercepted by the kernel and should -cause a system shutdown and power off. - -A Note About Mixed CPU Systems ------------------------------- - -Linux isn't designed to handle mixed CPU systems very well. In order -to get everything going you *must* make sure that your lowest -capability CPU is used for booting. Also, mixing CPU classes -(e.g. 486 and 586) is really not going to work very well at all. diff --git a/Documentation/watchdog/src/watchdog-simple.c b/Documentation/watchdog/src/watchdog-simple.c index 4cf72f3fa8e..ba45803a221 100644 --- a/Documentation/watchdog/src/watchdog-simple.c +++ b/Documentation/watchdog/src/watchdog-simple.c @@ -17,9 +17,6 @@ int main(void) ret = -1; break; } - ret = fsync(fd); - if (ret) - break; sleep(10); } close(fd); diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c index a750532ffcf..63fdc34ceb9 100644 --- a/Documentation/watchdog/src/watchdog-test.c +++ b/Documentation/watchdog/src/watchdog-test.c @@ -31,6 +31,8 @@ static void keep_alive(void) */ int main(int argc, char *argv[]) { + int flags; + fd = open("/dev/watchdog", O_WRONLY); if (fd == -1) { @@ -41,12 +43,14 @@ int main(int argc, char *argv[]) if (argc > 1) { if (!strncasecmp(argv[1], "-d", 2)) { - ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD); + flags = WDIOS_DISABLECARD; + ioctl(fd, WDIOC_SETOPTIONS, &flags); fprintf(stderr, "Watchdog card disabled.\n"); fflush(stderr); exit(0); } else if (!strncasecmp(argv[1], "-e", 2)) { - ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD); + flags = WDIOS_ENABLECARD; + ioctl(fd, WDIOC_SETOPTIONS, &flags); fprintf(stderr, "Watchdog card enabled.\n"); fflush(stderr); exit(0); diff --git a/Documentation/watchdog/watchdog-api.txt b/Documentation/watchdog/watchdog-api.txt index 4cc4ba9d715..eb7132ed8bb 100644 --- a/Documentation/watchdog/watchdog-api.txt +++ b/Documentation/watchdog/watchdog-api.txt @@ -222,11 +222,10 @@ returned value is the temperature in degrees fahrenheit. ioctl(fd, WDIOC_GETTEMP, &temperature); Finally the SETOPTIONS ioctl can be used to control some aspects of -the cards operation; right now the pcwd driver is the only one -supporting this ioctl. +the cards operation. int options = 0; - ioctl(fd, WDIOC_SETOPTIONS, options); + ioctl(fd, WDIOC_SETOPTIONS, &options); The following options are available: |