linux/drivers/firewire/core-cdev.c, branch v3.4-rc2

Remove all #inclusions of asm/system.h

2012-03-28T17:30:03Z

Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*.*\n!!' `grep -Irl '^#\s*include\s*' *` Signed-off-by: David Howells

firewire: allow explicit flushing of iso packet completions

2012-03-18T21:15:39Z

Extend the kernel and userspace APIs to allow reporting all currently completed isochronous packets, even if the next interrupt packet has not yet been reached. This is required to determine the status of the packets at the end of a paused or stopped stream, and useful for more precise synchronization of audio streams. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter

firewire: prevent dropping of completed iso packet header data

2012-03-18T21:15:39Z

The buffer for the header data of completed iso packets has a fixed size, so it is possible to configure a stream with a big interval between interrupt packets or with big headers so that this buffer would overflow. Previously, ohci.c would drop any data that would not fit, but this could make unsuspecting applications believe that fewer than the actual number of packets have completed. Instead of dropping data, add calls to flush_iso_completion() so that there are as many events as needed to report all of the data. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter

firewire: core: prefix log messages with card name

2012-02-22T21:36:00Z

Associate all log messages from firewire-core with the respective card because some people have more than one card. E.g. firewire_ohci 0000:04:00.0: added OHCI v1.10 device as card 0, 8 IR + 8 IT contexts, quirks 0x0 firewire_ohci 0000:05:00.0: added OHCI v1.10 device as card 1, 8 IR + 8 IT contexts, quirks 0x0 firewire_core: created device fw0: GUID 0814438400000389, S800 firewire_core: phy config: new root=ffc1, gap_count=5 firewire_core: created device fw1: GUID 0814438400000388, S800 firewire_core: created device fw2: GUID 0001d202e06800d1, S800 turns into firewire_ohci 0000:04:00.0: added OHCI v1.10 device as card 0, 8 IR + 8 IT contexts, quirks 0x0 firewire_ohci 0000:05:00.0: added OHCI v1.10 device as card 1, 8 IR + 8 IT contexts, quirks 0x0 firewire_core 0000:04:00.0: created device fw0: GUID 0814438400000389, S800 firewire_core 0000:04:00.0: phy config: new root=ffc1, gap_count=5 firewire_core 0000:05:00.0: created device fw1: GUID 0814438400000388, S800 firewire_core 0000:04:00.0: created device fw2: GUID 0001d202e06800d1, S800 This increases the module size slightly; to keep this in check, turn the former printk wrapper macros into functions. Their implementation is largely copied from driver core's dev_printk counterparts. Signed-off-by: Stefan Richter

firewire: cdev: fix 32 bit userland on 64 bit kernel compat corner cases

2011-08-12T13:30:08Z

Clemens points out that we need to use compat_ptr() in order to safely cast from u64 to addresses of a 32-bit usermode client. Before, our conversion went wrong - in practice if the client cast from pointer to integer such that sign-extension happened, (libraw1394 and libdc1394 at least were not doing that, IOW were not affected) or - in theory on s390 (which doesn't have FireWire though) and on the tile architecture, regardless of what the client does. The bug would usually be observed as the initial get_info ioctl failing with "Bad address" (EFAULT). Reported-by: Carl Karsten Reported-by: Clemens Ladisch Signed-off-by: Stefan Richter

firewire: cdev: prevent race between first get_info ioctl and bus reset event queuing

2011-07-16T05:24:32Z

Between open(2) of a /dev/fw* and the first FW_CDEV_IOC_GET_INFO ioctl(2) on it, the kernel already queues FW_CDEV_EVENT_BUS_RESET events to be read(2) by the client. The get_info ioctl is practically always issued right away after open, hence this condition only occurs if the client opens during a bus reset, especially during a rapid series of bus resets. The problem with this condition is twofold: - These bus reset events carry the (as yet undocumented) @closure value of 0. But it is not the kernel's place to choose closures; they are privat to the client. E.g., this 0 value forced from the kernel makes it unsafe for clients to dereference it as a pointer to a closure object without NULL pointer check. - It is impossible for clients to determine the relative order of bus reset events from get_info ioctl(2) versus those from read(2), except in one way: By comparison of closure values. Again, such a procedure imposes complexity on clients and reduces freedom in use of the bus reset closure. So, change the ABI to suppress queuing of bus reset events before the first FW_CDEV_IOC_GET_INFO ioctl was issued by the client. Note, this ABI change cannot be version-controlled. The kernel cannot distinguish old from new clients before the first FW_CDEV_IOC_GET_INFO ioctl. We will try to back-merge this change into currently maintained stable/ longterm series, and we only document the new behaviour. The old behavior is now considered a kernel bug, which it basically is. Signed-off-by: Stefan Richter Cc:

firewire: cdev: return -ENOTTY for unimplemented ioctls, not -EINVAL

2011-07-16T05:24:31Z

On Jun 27 Linus Torvalds wrote: > The correct error code for "I don't understand this ioctl" is ENOTTY. > The naming may be odd, but you should think of that error value as a > "unrecognized ioctl number, you're feeding me random numbers that I > don't understand and I assume for historical reasons that you tried to > do some tty operation on me". [...] > The EINVAL thing goes way back, and is a disaster. It predates Linux > itself, as far as I can tell. You'll find lots of man-pages that have > this line in it: > > EINVAL Request or argp is not valid. > > and it shows up in POSIX etc. And sadly, it generally shows up > _before_ the line that says > > ENOTTY The specified request does not apply to the kind of object > that the descriptor d references. > > so a lot of people get to the EINVAL, and never even notice the ENOTTY. [...] > At least glibc (and hopefully other C libraries) use a _string_ that > makes much more sense: strerror(ENOTTY) is "Inappropriate ioctl for > device" So let's correct this in the ABI while it is still young, relative to distributor adoption. Side note: We return -ENOTTY not only on _IOC_TYPE or _IOC_NR mismatch, but also on _IOC_SIZE mismatch. An ioctl with an unsupported size of argument structure can be seen as an unsupported version of that ioctl. Signed-off-by: Stefan Richter Cc:

firewire: sbp2: parallelize login, reconnect, logout

2011-05-10T20:53:46Z

The struct sbp2_logical_unit.work items can all be executed in parallel but are not reentrant. Furthermore, reconnect or re-login work must be executed in a WQ_MEM_RECLAIM workqueue. Hence replace the old single-threaded firewire-sbp2 workqueue by a concurrency-managed but non-reentrant workqueue with rescuer. firewire-core already maintains one, hence use this one. In earlier versions of this change, I observed occasional failures of parallel INQUIRY to an Initio INIC-2430 FireWire 800 to dual IDE bridge. More testing indicates that parallel INQUIRY is not actually a problem, but too quick successions of logout and login + INQUIRY, e.g. a quick sequence of cable plugout and plugin, can result in failed INQUIRY. This does not seem to be something that should or could be addressed by serialization. Another dual-LU device to which I currently have access to, an OXUF924DSB FireWire 800 to dual SATA bridge with firmware from MacPower, has been successfully tested with this too. This change is beneficial to environments with two or more FireWire storage devices, especially if they are located on the same bus. Management tasks that should be performed as soon and as quickly as possible, especially reconnect, are no longer held up by tasks on other devices that may take a long time, especially login with INQUIRY and sd or sr driver probe. Signed-off-by: Stefan Richter

firewire: core: use non-reentrant workqueue with rescuer

2011-05-10T20:53:45Z

firewire-core manages the following types of work items: fw_card.br_work: - resets the bus on a card and possibly sends a PHY packet before that - does not sleep for long or not at all - is scheduled via fw_schedule_bus_reset() by - firewire-ohci's pci_probe method - firewire-ohci's set_config_rom method, called by kernelspace protocol drivers and userspace drivers which add/remove Configuration ROM descriptors - userspace drivers which use the bus reset ioctl - itself if the last reset happened less than 2 seconds ago fw_card.bm_work: - performs bus management duties - usually does not (but may in corner cases) sleep for long - is scheduled via fw_schedule_bm_work() by - firewire-ohci's self-ID-complete IRQ handler tasklet - firewire-core's fw_device.work instances whenever the root node device was (successfully or unsuccessfully) discovered, refreshed, or rediscovered - itself in case of resource allocation failures or in order to obey the 125ms bus manager arbitration interval fw_device.work: - performs node probe, update, shutdown, revival, removal; including kernel driver probe, update, shutdown and bus reset notification to userspace drivers - usually sleeps moderately long, in corner cases very long - is scheduled by - firewire-ohci's self-ID-complete IRQ handler tasklet via the core's fw_node_event - firewire-ohci's pci_remove method via core's fw_destroy_nodes/ fw_node_event - itself during retries, e.g. while a node is powering up iso_resource.work: - accesses registers at the Isochronous Resource Manager node - usually does not (but may in corner cases) sleep for long - is scheduled via schedule_iso_resource() by - the owning userspace driver at addition and removal of the resource - firewire-core's fw_device.work instances after bus reset - itself in case of resource allocation if necessary to obey the 1000ms reallocation period after bus reset fw_card.br_work instances should not, and instances of the others must not, be executed in parallel by multiple CPUs -- but were not protected against that. Hence allocate a non-reentrant workqueue for them. fw_device.work may be used in the memory reclaim path in case of SBP-2 device updates. Hence we need a workqueue with rescuer and cannot use system_nrt_wq. Signed-off-by: Stefan Richter Reviewed-by: Tejun Heo

firewire: optimize iso queueing by setting wake only after the last packet

2011-05-10T20:53:45Z

When queueing iso packets, the run time is dominated by the two MMIO accesses that set the DMA context's wake bit. Because most drivers submit packets in batches, we can save much time by removing all but the last wakeup. The internal kernel API is changed to require a call to fw_iso_context_queue_flush() after a batch of queued packets. The user space API does not change, so one call to FW_CDEV_IOC_QUEUE_ISO must specify multiple packets to take advantage of this optimization. In my measurements, this patch reduces the time needed to queue fifty skip packets from userspace to one sixth on a 2.5 GHz CPU, or to one third at 800 MHz. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter