diff options
Diffstat (limited to 'Documentation')
77 files changed, 5221 insertions, 2434 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index e638e15a889..97ad190e13a 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -41,6 +41,49 @@ Description: for the device and attempt to bind to it. For example: # echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_id +What: /sys/bus/pci/drivers/.../remove_id +Date: February 2009 +Contact: Chris Wright <chrisw@sous-sol.org> +Description: + Writing a device ID to this file will remove an ID + that was dynamically added via the new_id sysfs entry. + The format for the device ID is: + VVVV DDDD SVVV SDDD CCCC MMMM. That is Vendor ID, Device + ID, Subsystem Vendor ID, Subsystem Device ID, Class, + and Class Mask. The Vendor ID and Device ID fields are + required, the rest are optional. After successfully + removing an ID, the driver will no longer support the + device. This is useful to ensure auto probing won't + match the driver to the device. For example: + # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id + +What: /sys/bus/pci/rescan +Date: January 2009 +Contact: Linux PCI developers <linux-pci@vger.kernel.org> +Description: + Writing a non-zero value to this attribute will + force a rescan of all PCI buses in the system, and + re-discover previously removed devices. + Depends on CONFIG_HOTPLUG. + +What: /sys/bus/pci/devices/.../remove +Date: January 2009 +Contact: Linux PCI developers <linux-pci@vger.kernel.org> +Description: + Writing a non-zero value to this attribute will + hot-remove the PCI device and any of its children. + Depends on CONFIG_HOTPLUG. + +What: /sys/bus/pci/devices/.../rescan +Date: January 2009 +Contact: Linux PCI developers <linux-pci@vger.kernel.org> +Description: + Writing a non-zero value to this attribute will + force a rescan of the device's parent bus and all + child buses, and re-discover devices removed earlier + from this part of the device tree. + Depends on CONFIG_HOTPLUG. + What: /sys/bus/pci/devices/.../vpd Date: February 2008 Contact: Ben Hutchings <bhutchings@solarflare.com> @@ -52,3 +95,30 @@ Description: that some devices may have malformatted data. If the underlying VPD has a writable section then the corresponding section of this file will be writable. + +What: /sys/bus/pci/devices/.../virtfnN +Date: March 2009 +Contact: Yu Zhao <yu.zhao@intel.com> +Description: + This symbolic link appears when hardware supports the SR-IOV + capability and the Physical Function driver has enabled it. + The symbolic link points to the PCI device sysfs entry of the + Virtual Function whose index is N (0...MaxVFs-1). + +What: /sys/bus/pci/devices/.../dep_link +Date: March 2009 +Contact: Yu Zhao <yu.zhao@intel.com> +Description: + This symbolic link appears when hardware supports the SR-IOV + capability and the Physical Function driver has enabled it, + and this device has vendor specific dependencies with others. + The symbolic link points to the PCI device sysfs entry of + Physical Function this device depends on. + +What: /sys/bus/pci/devices/.../physfn +Date: March 2009 +Contact: Yu Zhao <yu.zhao@intel.com> +Description: + This symbolic link appears when a device is a Virtual Function. + The symbolic link points to the PCI device sysfs entry of the + Physical Function this device associates with. diff --git a/Documentation/ABI/testing/sysfs-class-regulator b/Documentation/ABI/testing/sysfs-class-regulator index 873ef1fc156..e091fa87379 100644 --- a/Documentation/ABI/testing/sysfs-class-regulator +++ b/Documentation/ABI/testing/sysfs-class-regulator @@ -4,8 +4,8 @@ KernelVersion: 2.6.26 Contact: Liam Girdwood <lrg@slimlogic.co.uk> Description: Some regulator directories will contain a field called - state. This reports the regulator enable status, for - regulators which can report that value. + state. This reports the regulator enable control, for + regulators which can report that input value. This will be one of the following strings: @@ -14,16 +14,54 @@ Description: 'unknown' 'enabled' means the regulator output is ON and is supplying - power to the system. + power to the system (assuming no error prevents it). 'disabled' means the regulator output is OFF and is not - supplying power to the system.. + supplying power to the system (unless some non-Linux + control has enabled it). 'unknown' means software cannot determine the state, or the reported state is invalid. NOTE: this field can be used in conjunction with microvolts - and microamps to determine regulator output levels. + or microamps to determine configured regulator output levels. + + +What: /sys/class/regulator/.../status +Description: + Some regulator directories will contain a field called + "status". This reports the current regulator status, for + regulators which can report that output value. + + This will be one of the following strings: + + off + on + error + fast + normal + idle + standby + + "off" means the regulator is not supplying power to the + system. + + "on" means the regulator is supplying power to the system, + and the regulator can't report a detailed operation mode. + + "error" indicates an out-of-regulation status such as being + disabled due to thermal shutdown, or voltage being unstable + because of problems with the input power supply. + + "fast", "normal", "idle", and "standby" are all detailed + regulator operation modes (described elsewhere). They + imply "on", but provide more detail. + + Note that regulator status is a function of many inputs, + not limited to control inputs from Linux. For example, + the actual load presented may trigger "error" status; or + a regulator may be enabled by another user, even though + Linux did not enable it. What: /sys/class/regulator/.../type @@ -58,7 +96,7 @@ Description: Some regulator directories will contain a field called microvolts. This holds the regulator output voltage setting measured in microvolts (i.e. E-6 Volts), for regulators - which can report that voltage. + which can report the control input for voltage. NOTE: This value should not be used to determine the regulator output voltage level as this value is the same regardless of @@ -73,7 +111,7 @@ Description: Some regulator directories will contain a field called microamps. This holds the regulator output current limit setting measured in microamps (i.e. E-6 Amps), for regulators - which can report that current. + which can report the control input for a current limit. NOTE: This value should not be used to determine the regulator output current level as this value is the same regardless of @@ -87,7 +125,7 @@ Contact: Liam Girdwood <lrg@slimlogic.co.uk> Description: Some regulator directories will contain a field called opmode. This holds the current regulator operating mode, - for regulators which can report it. + for regulators which can report that control input value. The opmode value can be one of the following strings: @@ -101,7 +139,8 @@ Description: NOTE: This value should not be used to determine the regulator output operating mode as this value is the same regardless of - whether the regulator is enabled or disabled. + whether the regulator is enabled or disabled. A "status" + attribute may be available to determine the actual mode. What: /sys/class/regulator/.../min_microvolts diff --git a/Documentation/ABI/testing/sysfs-fs-ext4 b/Documentation/ABI/testing/sysfs-fs-ext4 new file mode 100644 index 00000000000..4e79074de28 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-fs-ext4 @@ -0,0 +1,81 @@ +What: /sys/fs/ext4/<disk>/mb_stats +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + Controls whether the multiblock allocator should + collect statistics, which are shown during the unmount. + 1 means to collect statistics, 0 means not to collect + statistics + +What: /sys/fs/ext4/<disk>/mb_group_prealloc +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + The multiblock allocator will round up allocation + requests to a multiple of this tuning parameter if the + stripe size is not set in the ext4 superblock + +What: /sys/fs/ext4/<disk>/mb_max_to_scan +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + The maximum number of extents the multiblock allocator + will search to find the best extent + +What: /sys/fs/ext4/<disk>/mb_min_to_scan +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + The minimum number of extents the multiblock allocator + will search to find the best extent + +What: /sys/fs/ext4/<disk>/mb_order2_req +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + Tuning parameter which controls the minimum size for + requests (as a power of 2) where the buddy cache is + used + +What: /sys/fs/ext4/<disk>/mb_stream_req +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + Files which have fewer blocks than this tunable + parameter will have their blocks allocated out of a + block group specific preallocation pool, so that small + files are packed closely together. Each large file + will have its blocks allocated out of its own unique + preallocation pool. + +What: /sys/fs/ext4/<disk>/inode_readahead +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + Tuning parameter which controls the maximum number of + inode table blocks that ext4's inode table readahead + algorithm will pre-read into the buffer cache + +What: /sys/fs/ext4/<disk>/delayed_allocation_blocks +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + This file is read-only and shows the number of blocks + that are dirty in the page cache, but which do not + have their location in the filesystem allocated yet. + +What: /sys/fs/ext4/<disk>/lifetime_write_kbytes +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + This file is read-only and shows the number of kilobytes + of data that have been written to this filesystem since it was + created. + +What: /sys/fs/ext4/<disk>/session_write_kbytes +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + This file is read-only and shows the number of + kilobytes of data that have been written to this + filesystem since it was mounted. diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 2a3fcc55e98..d9aa43d78bc 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -609,3 +609,109 @@ size is the size (and should be a page-sized multiple). The return value will be either a pointer to the processor virtual address of the memory, or an error (via PTR_ERR()) if any part of the region is occupied. + +Part III - Debug drivers use of the DMA-API +------------------------------------------- + +The DMA-API as described above as some constraints. DMA addresses must be +released with the corresponding function with the same size for example. With +the advent of hardware IOMMUs it becomes more and more important that drivers +do not violate those constraints. In the worst case such a violation can +result in data corruption up to destroyed filesystems. + +To debug drivers and find bugs in the usage of the DMA-API checking code can +be compiled into the kernel which will tell the developer about those +violations. If your architecture supports it you can select the "Enable +debugging of DMA-API usage" option in your kernel configuration. Enabling this +option has a performance impact. Do not enable it in production kernels. + +If you boot the resulting kernel will contain code which does some bookkeeping +about what DMA memory was allocated for which device. If this code detects an +error it prints a warning message with some details into your kernel log. An +example warning message may look like this: + +------------[ cut here ]------------ +WARNING: at /data2/repos/linux-2.6-iommu/lib/dma-debug.c:448 + check_unmap+0x203/0x490() +Hardware name: +forcedeth 0000:00:08.0: DMA-API: device driver frees DMA memory with wrong + function [device address=0x00000000640444be] [size=66 bytes] [mapped as +single] [unmapped as page] +Modules linked in: nfsd exportfs bridge stp llc r8169 +Pid: 0, comm: swapper Tainted: G W 2.6.28-dmatest-09289-g8bb99c0 #1 +Call Trace: + <IRQ> [<ffffffff80240b22>] warn_slowpath+0xf2/0x130 + [<ffffffff80647b70>] _spin_unlock+0x10/0x30 + [<ffffffff80537e75>] usb_hcd_link_urb_to_ep+0x75/0xc0 + [<ffffffff80647c22>] _spin_unlock_irqrestore+0x12/0x40 + [<ffffffff8055347f>] ohci_urb_enqueue+0x19f/0x7c0 + [<ffffffff80252f96>] queue_work+0x56/0x60 + [<ffffffff80237e10>] enqueue_task_fair+0x20/0x50 + [<ffffffff80539279>] usb_hcd_submit_urb+0x379/0xbc0 + [<ffffffff803b78c3>] cpumask_next_and+0x23/0x40 + [<ffffffff80235177>] find_busiest_group+0x207/0x8a0 + [<ffffffff8064784f>] _spin_lock_irqsave+0x1f/0x50 + [<ffffffff803c7ea3>] check_unmap+0x203/0x490 + [<ffffffff803c8259>] debug_dma_unmap_page+0x49/0x50 + [<ffffffff80485f26>] nv_tx_done_optimized+0xc6/0x2c0 + [<ffffffff80486c13>] nv_nic_irq_optimized+0x73/0x2b0 + [<ffffffff8026df84>] handle_IRQ_event+0x34/0x70 + [<ffffffff8026ffe9>] handle_edge_irq+0xc9/0x150 + [<ffffffff8020e3ab>] do_IRQ+0xcb/0x1c0 + [<ffffffff8020c093>] ret_from_intr+0x0/0xa + <EOI> <4>---[ end trace f6435a98e2a38c0e ]--- + +The driver developer can find the driver and the device including a stacktrace +of the DMA-API call which caused this warning. + +Per default only the first error will result in a warning message. All other +errors will only silently counted. This limitation exist to prevent the code +from flooding your kernel log. To support debugg |