<linux/mod_devicetable.h> is included in a many files:
$ git grep '<linux/mod_devicetable.h>' ef0c9f75a1 | wc -l
1598
; some of them are widely used headers. To stop mixing up different and
unrelated driver( type)s let the subsystem headers only use the subset
of the recently split <linux/mod_devicetable.h> that are relevant for
them.
The fallout (I hope) is addressed in the previous commits that handle
sources relying on e.g. <linux/i2c.h> pulling in the full legacy header
and thus providing pci_device_id.
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://patch.msgid.link/199fe46b624ba07fb9bd3e0cd6ff13757932cb5f.1782808461.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
For single-channel isochronous contexts, the header storage size is
hard-coded to PAGE_SIZE. which is inconvenient for protocol
implementations requiring more space.
This commit refactors the code to obtain the header storage size outside
the 1394 OHCI driver.
Link: https://lore.kernel.org/r/20260117142823.440811-8-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The fw_iso_callback union was added by a commit ebe4560ed5 ("firewire:
Remove function callback casts") to remove function pointer cast.
That change affected the cdev layer of the core code, but it is more
convenient for fw_iso_context_create() to accept the union directly.
This commit renames and changes the existing function to take the union
argument, and add static inline wrapper functions as variants.
Link: https://lore.kernel.org/r/20260117142823.440811-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
TASCAM FW-1884/FW-1804/FW-1082 is too lazy to repspond to asynchronous
request at S400. The asynchronous transaction often results in timeout.
This is a problematic quirk.
This commit adds support for the quirk. When identifying the new quirk
flag, then the transaction speed is configured at S200.
Link: https://lore.kernel.org/r/20251018035532.287124-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
A commit 3a93d082ba ("ALSA: firewire-motu: add support for MOTU Audio
Express") describes a quirk of MOTU Audio Express. The device returns
acknowledge packet with 0x10 as the pending state of any types of
asynchronous request transaction. It is completely out of specification.
This commit implements handling for that device-specific quirk. The quirk
is detected after reading the root directory of configuration ROM. When
processing the acknowledge code in 1394 OHCI AT context event handler,
firewire-ohci module seeks the device instance of destination node by
traversing device hierarchy. If the device has the quirk, the acknowledge
code is replaced with the standard code.
The 1394 OHCI AT context events occur for outgoing asynchronous request
packets. The device traversal is safe since no new request initiators
exist after the fw_card_instance has been invalidated.
Link: https://lore.kernel.org/r/20251013140311.97159-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Every time the bus manager runs, the cached configuration ROM content of
the IRM device is investigated to detect device-specific quirks. This
detection can be performed in advance when reading the configuration ROM.
This commit adds device quirk flags to the fw_device structure, and
initializes them after reading the bus information block of the
configuration ROM. The quirk flags are immutable once the configuration
ROM has been read. Although they are likely accessed concurrently only by
the bus manager, this commit ensures safe access by preventing torn writes
and reads using the WRITE_ONCE()/READ_ONCE() macros.
Link: https://lore.kernel.org/r/20251013140311.97159-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
At present the parameters to compute timeout time for split transaction is
protected by card-wide spin lock, while it is not necessarily convenient
in a point to narrower critical section.
This commit adds and uses another spin lock specific for the purpose.
Link: https://lore.kernel.org/r/20250915234747.915922-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The list of instance for asynchronous transaction to wait for response
subaction is maintained as a member of fw_card structure. The card-wide
spinlock is used at present for any operation over the list, however it
is not necessarily suited for the purpose.
This commit adds and uses the spin lock specific to maintain the list.
Link: https://lore.kernel.org/r/20250915234747.915922-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
At present, the operation for read transaction to topology map register is
not protected by any kind of lock primitives. This causes a potential
problem to result in the mixed content of topology map.
This commit adds and uses spin lock specific to topology map.
Link: https://lore.kernel.org/r/20250915234747.915922-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The lifetime of address handler has been managed by linked list and RCU.
This approach was introduced in commit 35202f7d84 ("firewire: remove
global lock around address handlers, convert to RCU"). The invocations of
address handler are performed within RCU read-side critical sections.
In commit 57e6d9f85f ("firewire: ohci: use workqueue to handle events
of AR request/response contexts"), the invocations are in a workqueue
context. The approach still imposes limitation that sleeping is not
allowed within RCU read-side critical sections. However, since sleeping
is not permitted within RCU read-side critical sections, this approach
still has a limitation.
This commit adds reference counting to decouple handler invocation from
handler discovery. The linked list and RCU is used to discover the
handlers, while the reference counting is used to invoke them safely.
Link: https://lore.kernel.org/r/20250803122015.236493-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
This commit adds a work item to handle events of 1394 OHCI AT
request/response contexts, and queues the item to the specific
workqueue. The call of struct fw_packet.callbaqck() is done in the
workqueue when receiving acknowledgement to the asynchronous packet
transferred to remote node.
Link: https://lore.kernel.org/r/20250615133253.433057-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Some tasklets (softIRQs) are still used as bottom-halves to handle
events for 1394 OHCI AR/AT contexts. However, using softIRQs for IRQ
bottom halves is generally discouraged today.
This commit adds a per-fw_card workqueue to accommodate the behaviour
specified by the 1394 OHCI specification.
According to the 1394 OHCI specification, system memory pages are
reserved for each asynchronous DMA context. This allows concurrent
operation across contexts. In the 1394 OHCI PCI driver implementation,
the hardware generates IRQs either upon receiving asynchronous packets
from other nodes (incoming) or after completing transmission to them
(outgoing). These independent events can occur in the same transmission
cycle, therefore the max_active parameter for the workqueue is set to the
total number of AR/AT contexts (=4). The WQ_UNBOUND flag is used to
allow the work to be scheduled on any available core, since there is
little CPU cache affinity benefit for the data.
Each DMA context uses a circular descriptor list in system memory,
allowing deferred data processing in software as long as buffer overrun
are avoided. Since the overall operation is sleepable except for small
atomic regions, WQ_BH is not used. As the descriptors contain
timestamps, WQ_HIGHPRI is specified to support semi-real-time
processing.
The asynchronous context is also used by the SCSI over IEEE 1394
protocol implementation (sbp2), which can be part of memory reclaim paths.
Therefore, WQ_MEM_RECLAIM is required.
To allow uses to adjust CPU affinity according to workload, WQ_SYSFS is
specified so that workqueue attributes are exposed to user space.
Link: https://lore.kernel.org/r/20250615133253.433057-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In current implementation, test_and_set_bit_lock() is used to mediate
concurrent calls of ohci_flush_iso_completions(). However, the ad-hoc
usage of atomic operations is not preferable.
This commit uses mutex_trylock() as the similar operations. The core
function is responsible for the mediation, instead of 1394 OHCI driver.
Link: https://lore.kernel.org/r/20240909140018.65289-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In packet-per-buffer mode for isochronous context of 1394 OHCI, software
can schedule hardIRQ to the buffer in which the content of isochronous
packet is processed. The actual behaviour is different between isochronous
receive (IR) and transmit (IT) contexts in respect to isochronous cycle in
which the hardIRQ occurs.
In IR context, the hardIRQ occurs when the buffer is filled actually by
the content of received packet. If there are any isochronous cycles in
which the packet transmission is skipped, it is postponed to generate
the hardIRQ in respect to the isochronous cycle. In IT context, software
can schedule the content of packet every isochronous cycle including
skipping, therefore the hardIRQ occurs in the isochronous cycle to which
the software scheduled.
ALSA firewire stack uses the packet-per-buffer mode for both IR/IT
contexts. To process time stamp per packet (or per sample in some cases)
steadily for media clock recovery against unexpected transmission skips,
it uses an IT context to operate all of isochronous contexts by calls of
fw_iso_context_flush_completions() in the bottom-half of hardIRQ for the
IT context.
Although it looks well to handle all of isochronous contexts in a single
bottom-half context, it relatively takes longer time. In the future code
integration (not yet), it is possible to apply parallelism method to
process these context. In the case, it is useful to allow unit drivers to
schedule work items to process these isochronous contexts.
As a preparation, this commit exposes
fw_iso_context_schedule_flush_completions() as a kernel API available by
unit drivers. It is renamed from fw_iso_context_queue_work() since it is
a counter part of fw_iso_context_flush_completions().
Link: https://lore.kernel.org/r/20240908040549.75304-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
This commit adds a workqueue dedicated for isochronous context processing.
The workqueue is allocated per instance of fw_card structure to satisfy the
following characteristics descending from 1394 OHCI specification:
In 1394 OHCI specification, memory pages are reserved to each isochronous
context dedicated to DMA transmission. It allows to operate these
per-context pages concurrently. Software can schedule hardware interrupt
for several isochronous context to the same cycle, thus WQ_UNBOUND is
specified. Additionally, it is sleepable to operate the content of pages,
thus WQ_BH is not used.
The isochronous context delivers the packets with time stamp, thus
WQ_HIGHPRI is specified for semi real-time data such as IEC 61883-1/6
protocol implemented by ALSA firewire stack. The isochronous context is not
used by the implementation of SCSI over IEEE1394 protocol (sbp2), thus
WQ_MEM_RECLAIM is not specified.
It is useful for users to adjust cpu affinity of the workqueue depending
on their work loads, thus WQ_SYS is specified to expose the attributes to
user space.
Tested-by: Edmund Raile <edmund.raile@protonmail.com>
Link: https://lore.kernel.org/r/20240904125155.461886-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/ZgIrOuR3JI/jzqoH@neat
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Uwe Kleine-König (The Capable Hub)
Takashi Sakamoto
Gustavo A. R. SilvaandTakashi Sakamoto