card->local_node and card->bm_retries are both always accessed under
card->lock.
fw_core_handle_bus_reset has a check whose condition depends on
card->local_node and whose body writes to card->bm_retries.
Both of these accesses are not under card->lock. Move the lock acquiring
of card->lock to before this check such that these accesses do happen
when card->lock is held.
fw_destroy_nodes is called inside the check.
Since fw_destroy_nodes already acquires card->lock inside its function
body, move this out to the callsites of fw_destroy_nodes.
Also add a comment to indicate which locking is necessary when calling
fw_destroy_nodes.
Cc: <stable@vger.kernel.org>
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20220409041243.603210-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
1394 OHCI specification defined Isochronous Cycle Timer Register to get
value of CYCLE_TIME register defined by IEEE 1394 for CSR architecture
defined by ISO/IEC 13213. Unit driver can calculate packet time by
compute with the value of CYCLE_TIME and timeStamp field in descriptor
of each isochronous and asynchronous context. The resolution of CYCLE_TIME
is 49.576 MHz, while the one of timeStamp is 8,000 Hz.
Current implementation of Linux FireWire subsystem allows the driver to
get the value of CYCLE_TIMER CSR register by transaction service. The
transaction service has overhead in regard of access to MMIO register.
This commit adds kernel API for unit driver to access the register
directly.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20220405072221.226217-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
(Hector Martin wrote)
This fixes segfaults when a card gets yanked off of the PCIe bus while
busy, e.g. with a userspace app trying to get the cycle time:
[8638860.994310] Call Trace:
[8638860.994313] ioctl_get_cycle_timer2+0x4f/0xd0 [firewire_core]
[8638860.994323] fw_device_op_ioctl+0xae/0x150 [firewire_core]
[8638860.994328] __x64_sys_ioctl+0x7d/0xb0
[8638860.994332] do_syscall_64+0x45/0x80
[8638860.994337] entry_SYSCALL_64_after_hwframe+0x44/0xae
(Takashi Sakamoto wrote)
As long as reading commit 2080222429 ("firewire: core: add forgotten
dummy driver methods, remove unused ones"), three functions are not
implemeted in dummy driver for reason; .read_csr, .write_csr, and
.set_config_rom.
In core of Linux FireWire subsystem, the callback of .set_config_rom is
under acquisition of mutual exclusive for local list of card. The
acquision is also done in process for removal of card, therefore it's
safe for missing implementation of .set_config_rom.
On the other hand, no lock primitive accompanies any call of .read_csr and
.write_csr. For userspace client, check of node shutdown is done in the
beginning of dispatch of ioctl request, while node shifts to shutdown
state in workqueue context enough after card shifts to dummy driver. It's
probable that these two functions are called for the dummy driver by the
code of userspace client. In-kernel unit driver has similar situation.
It's better to add implementation of the two functions for dummy driver.
Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20220405072221.226217-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1334 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull IEEE 1394 (FireWire) subsystem updates from Stefan Richter:
- Fix mismatch between DMA mapping direction (was wrong) and DMA
synchronization direction (was correct) of isochronous reception
buffers of userspace drivers if vma-mapped for R/W access. For
example, libdc1394 was affected.
- more consistent retry stategy in device discovery/ rediscovery, and
improved failure diagnostics
- various small cleanups, e.g. use SCSI layer's DMA mapping API in
firewire-sbp2
* tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
firewire: sbp2: document the absence of alignment requirements
firewire: sbp2: remove superfluous blk_queue_max_segment_size() call
firewire: sbp2: use scsi_dma_(un)map
firewire: sbp2: give correct DMA device to scsi framework
firewire: core: fw_device_refresh(): clean up error handling
firewire: core: log config rom reading errors
firewire: core: log error in case of failed bus manager lock
firewire: move rcode_string() to core
firewire: core: improve reread_config_rom() interface
firewire: core: wait for inaccessible devices after bus reset
firewire: ohci: omit spinlock IRQ flags where possible
firewire: ohci: correct signedness of a local variable
firewire: core: fix DMA mapping direction
firewire: use module_pci_driver
When writing a firewire driver that doesn't deal with struct fw_device
objects (e.g. it only publishes FireWire units and doesn't subscribe to
them), you likely need to keep referenced to struct fw_card objects so
that you can send messages to other nodes. This patch moves
fw_card_put(), fw_card_get() and fw_card_release() into the public
include/linux/firewire.h header instead of drivers/firewire/core.h, and
adds EXPORT_SYMBOL_GPL(fw_card_release).
The firewire-sbp-target module requires these so it can keep a reference
to the fw_card object in order that it can fetch ORBs to execute and
read/write related data and status information.
Signed-off-by: Chris Boot <bootc@bootc.net>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
If the lock access to the bus manager register fails, also log the
actual error that caused it to fail.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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 <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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 <stefanr@s5r6.in-berlin.de>
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 <stefanr@s5r6.in-berlin.de>
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 <stefanr@s5r6.in-berlin.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
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 <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
We do not need slab allocations anymore in order to satisfy
streaming DMA mapping constraints, thanks to commit da28947e7e
"firewire: ohci: avoid separate DMA mapping for small AT payloads".
(Besides, the slab-allocated buffers that firewire-core, firewire-sbp2,
and firedtv used to provide for 8-byte write and lock requests were
still not fully portable since they crossed cacheline boundaries or
shared a cacheline with unrelated CPU-accessed data. snd-firewire-lib
got this aspect right by using an extra kmalloc/ kfree just for the
8-byte transaction buffer.)
This change replaces kmalloc'ed lock transaction scratch buffers in
firewire-core, firedtv, and snd-firewire-lib by local stack allocations.
Perhaps the most notable result of the change is simpler locking because
there is no need to serialize usages of preallocated per-device buffers
anymore. Also, allocations and deallocations are simpler.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
The SPLIT_TIMEOUT mechanism is intended to detect requests that somehow
got lost. However, when the timeout value is too low, transactions that
could have been completed successfully will be cancelled. Furthermore,
there are chips whose firmwares ignore the configured split timeout and
send late split response; known examples are the DM1x00 (BeBoB), TCD22x0
(DICE), and some OXUF936QSE firmwares.
This patch changes the default timeout to two seconds, which happens to
be the default on other OSes, too.
Actual lost requests are extremely rare, so there should be no practical
downside to increasing the split timeout even on devices that work
correctly.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
On a 32-bit machine with, e.g., HZ=1000, jiffies will overflow after
about 50 days, so if there are between 25 and 50 days between bus
resets, the card->reset_jiffies comparisons can get wrong results.
To fix this, ensure that this timestamp always uses 64 bits.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: "Stefan Richter" <stefanr@s5r6.in-berlin.de>
Regression since commit 1038953674, "firewire: core: check for 1394a
compliant IRM, fix inaccessibility of Sony camcorder":
The camcorder Canon MV5i generates lots of bus resets when asynchronous
requests are sent to it (e.g. Config ROM read requests or FCP Command
write requests) if the camcorder is not root node. This causes drop-
outs in videos or makes the camcorder entirely inaccessible.
https://bugzilla.redhat.com/show_bug.cgi?id=633260
Fix this by allowing any Canon device, even if it is a pre-1394a IRM
like MV5i are, to remain root node (if it is at least Cycle Master
capable). With the FireWire controller cards that I tested, MV5i always
becomes root node when plugged in and left to its own devices.
Reported-by: Ralf Lange
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: <stable@kernel.org> # 2.6.32.y and newer
Conflicts:
drivers/firewire/core-card.c
drivers/firewire/core-cdev.c
and forgotten #include <linux/time.h> in drivers/firewire/ohci.c
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
There is an at least theoretic race condition in which .start_iso etc.
could still be called between when the dummy driver is bound to the card
and when the children devices are being shut down. Add dummy_start_iso
and friends.
On the other hand, .enable, .set_config_rom, .read_csr, write_csr do not
need to be implemented by the dummy driver, as commented.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Add an FW_CDEV_IOC_RECEIVE_PHY_PACKETS ioctl() and
FW_CDEV_EVENT_PHY_PACKET_RECEIVED poll()/read() event for /dev/fw*.
This can be used to get information from remote PHYs by remote access
PHY packets.
This is also the 2nd half of the functionality (the receive part) to
support a userspace implementation of a VersaPHY transaction layer.
Safety considerations:
- PHY packets are generally broadcasts, hence some kind of elevated
privileges should be required of a process to be able to listen in
on PHY packets. This implementation assumes that a process that is
allowed to open the /dev/fw* of a local node does have this
privilege.
There was an inconclusive discussion about introducing POSIX
capabilities as a means to check for user privileges for these
kinds of operations.
Other limitations:
- PHY packet reception may be switched on by ioctl() but cannot be
switched off again. It would be trivial to provide an off switch,
but this is not worth the code. The client should simply close()
the fd then, or just ignore further events.
- For sake of simplicity of API and kernel-side implementation, no
filter per packet content is provided.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
core-transaction.c transmit_complete_callback() and close_transaction()
expect packet callback status to be an ACK or RCODE, and ACKs get
translated to RCODEs for transaction callbacks.
An old comment on the packet callback API (been there from the initial
submission of the stack) and the dummy_driver implementation of
send_request/send_response deviated from this as they also included
-ERRNO in the range of status values.
Let's narrow status values down to ACK and RCODE to prevent surprises.
RCODE_CANCELLED is chosen as the dummy_driver's RCODE as its meaning of
"transaction timed out" comes closest to what happens when a transaction
coincides with card removal.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Bus resets which are triggered
- by the kernel drivers after updates of the local nodes' config ROM,
- by userspace software via ioctl
shall be deferred until after >=2 seconds after the last bus reset.
If multiple modifications of the local nodes' config ROM happen in a row,
only a single bus reset should happen after them.
When the local node's link goes from inactive to active or vice versa,
and at the two occasions of bus resets mentioned above --- and if the
current gap count differs from 63 --- the bus reset should be preceded
by a PHY configuration packet that reaffirms the gap count. Otherwise a
bus manager would have to reset the bus again right after that.
This is necessary to promote bus stability, e.g. leave grace periods for
allocations and reallocations of isochronous channels and bandwidth,
SBP-2 reconnections etc.; see IEEE 1394 clause 8.2.1.
This change implements all of the above by moving bus reset initiation
into a delayed work (except for bus resets which are triggered by the
bus manager workqueue job and are performed there immediately). It
comes with a necessary addition to the card driver methods that allows
to get the current gap count from PHY registers.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Fix an obscure ABI feature that is a bit of a hassle to implement.
However, somebody put it into the ABI, so let's fill in a sensible
value there.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Takashi Iwai
Niels Dossche
Takashi Sakamoto
Hector Martin
Thomas Gleixner
Linus Torvalds
Chris Boot
Clemens Ladisch
Stefan Richter
Arun Sharma