linux-stable.git/drivers/firewire, branch linux-6.17.y

firewire: ohci: move self_id_complete tracepoint after validating register

2025-11-13T20:36:47+00:00

[ Upstream commit 696968262aeee51e1c0529c3c060ddd180702e02 ]

The value of OHCI1394_SelfIDCount register includes an error-indicating
bit. It is safer to place the tracepoint probe after validating the
register value.

Link: https://lore.kernel.org/r/20250823030954.268412-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto 
Signed-off-by: Sasha Levin

firewire: core: fix overlooked update of subsystem ABI version

2025-09-20T03:17:50+00:00

In kernel v6.5, several functions were added to the cdev layer. This
required updating the default version of subsystem ABI up to 6, but
this requirement was overlooked.

This commit updates the version accordingly.

Fixes: 6add87e9764d ("firewire: cdev: add new version of ABI to notify time stamp at request/response subaction of transaction#")
Link: https://lore.kernel.org/r/20250920025148.163402-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto

firewire: core: reallocate buffer for FCP address handlers when more than 4 are registered

2025-08-03T12:20:15+00:00

The former commit has a limitation that only up to 4 FCP address
handlers could be processed per request. Although it suffices for most
use cases, it is technically a regression.

This commit lifts the restriction by reallocating the buffer from kernel
heap when more than 4 handlers are registered. The allocation is performed
within RCU read-side critical section, thus it uses GCP_ATOMIC flag. The
buffer size is rounded up to the next power of two to align with kmalloc
allocation units.

Link: https://lore.kernel.org/r/20250803122015.236493-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto

firewire: core: call FCP address handlers outside RCU read-side critical section

2025-08-03T12:20:14+00:00

The former commit added reference counting to ensure safe invocations of
address handlers. Unlike the exclusive-region address handlers, all FCP
address handlers should be called on receiving an FCP request.

This commit uses the part of kernel stack to collect address handlers up
to 4 within the section, then invoke them outside of the section.
Reference counting ensures that each handler remains valid and safe to
call.

Lifting the limitation of supporting only 4 handlers is left for next
work.

Link: https://lore.kernel.org/r/20250803122015.236493-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto

firewire: core: call handler for exclusive regions outside RCU read-side critical section

2025-08-03T12:20:13+00:00

The previous commit added reference counting to ensure safe invocations of
address handlers.

This commit moves the invocation of handlers for exclusive regions outside
of the RCU read-side critical section. The address handler for the
requested region is selected within the critical section, then invoked
outside of it.

Link: https://lore.kernel.org/r/20250803122015.236493-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto

firewire: core: use reference counting to invoke address handlers safely

2025-08-11T13:22:33+00:00

The lifetime of address handler has been managed by linked list and RCU.
This approach was introduced in commit 35202f7d8420 ("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 57e6d9f85fff ("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

firewire: ohci: reduce the size of common context structure by extracting members into AT structure

2025-07-12T12:52:16+00:00

In commit 386a4153a2c1 ("firewire: ohci: cache the context run bit"), a
running member was added to the context structure to cache the running
state of a given DMA context. Although this member is accessible from IR,
IT, and AT contexts, it is currently used only by the AT context.

Additionally, the context structure includes a work item, which is also
used by the AT context. Both members are unnecessary for IR and IT
contexts.

This commit refactors the code by moving these two members into a new
structure specific to AT context.

Link: https://lore.kernel.org/r/20250710131916.31289-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto

firewire: core: minor code refactoring to localize table of gap count

2025-06-17T00:56:42+00:00

The table for gap count is accessed by a single function. In this case,
it can be localized to the function.

Link: https://lore.kernel.org/r/20250617004320.477421-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto

firewire: ohci: use workqueue to handle events of AT request/response contexts

2025-06-15T13:40:29+00:00

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

firewire: ohci: use workqueue to handle events of AR request/response contexts

2025-06-15T13:40:29+00:00

This commit adds a work item to handle events of 1394 OHCI AR
request/response contexts, and queues the item to the specific workqueue.
The call of struct fw_address_handler.address_callback() is done in the
workqueue when receiving any requests from the remove nodes. Additionally,
the call of struct fw_packet.callback() is done in the workqueue too when
receiving acknowledge to the asynchronous packet for the response
subaction of split transaction to the remote nodes.

Link: https://lore.kernel.org/r/20250615133253.433057-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto