[GIT PULL] firewire updates for v6.17 kernel

[Takashi Sakamoto <o-takashi@sakamocchi.jp>]

Hi Linus,

Please apply the changes from FireWire subsystem to your tree.

This update completes the removal of tasklet usage from the subsystem.
The bottom halves for all 1394 OHCI DMA contexts are now handled by
standard workqueues.

Based on observations from tracepoints events added between v6.10 and
v6.11, the replacement appears to function as intended. However, an
issue remains where 'schedule()' may be invoked within an RCU read-side
critical section. A proposed fix for this issue has been submitted and is
currently under review and testing. As the fix is still recent, it has
been excluded from this PR, and will be sent after the release of
v6.17-rc1.


The following changes since commit 19272b37aa4f83ca52bdf9c16d5d81bdd1354494:

  Linux 6.16-rc1 (2025-06-08 13:44:43 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394.git tags/firewire-updates-6.17

for you to fetch changes up to 95a042a0c8ecd3c1e886648f6f6ab9c7e4403db9:

  firewire: ohci: reduce the size of common context structure by extracting members into AT structure (2025-07-12 21:52:16 +0900)

----------------------------------------------------------------
firewire updates for v6.17

This update replaces the remaining tasklet usage in the FireWire subsystem
with workqueue for asynchronous packet transmission. With this change,
tasklets are now fully eliminated from the subsystem.

Asynchronous packet transmission is used for serial bus topology
management as well as for the operation of the SBP-2 protocol driver
(firewire-sbp2). To ensure reliability during low-memory conditions, the
associated workqueue is created with the WQ_MEM_RECLAIM flag, allowing it
to participate in memory reclaim paths. Other attributes are aligned with
those used for isochronous packet handling, which was migrated to
workqueues in v6.12.

The workqueues are sleepable and support preemptible work items, making
them more suitable for real-time workloads that benefit from timely task
preemption at the system level.

There remains an issue where 'schedule()' may be called within an RCU
read-side critical section, due to a direct replacement of
'tasklet_disable_in_atomic()' with 'disable_work_sync()'. A proposed fix
for this has been posted[1], and is currently under review and testing.
It is expected to be sent upstream later.

 [1] https://lore.kernel.org/lkml/20250728015125.17825-1-o-takashi@sakamocchi.jp/

----------------------------------------------------------------
Takashi Sakamoto (8):
      firewire: ohci: correct code comments about bus_reset tasklet
      firewire: ohci: use from_work() macro to expand parent structure of work_struct
      firewire: core: use from_work() macro to expand parent structure of work_struct
      firewire: core: allocate workqueue for AR/AT request/response contexts
      firewire: ohci: use workqueue to handle events of AR request/response contexts
      firewire: ohci: use workqueue to handle events of AT request/response contexts
      firewire: core: minor code refactoring to localize table of gap count
      firewire: ohci: reduce the size of common context structure by extracting members into AT structure

 drivers/firewire/core-card.c        |  59 +++++++++++++++++++++++++++++++++++++++--------------------
 drivers/firewire/core-cdev.c        |   3 +--
 drivers/firewire/core-device.c      |  15 +++++----------
 drivers/firewire/core-transaction.c |   7 ++++---
 drivers/firewire/net.c              |   4 ++--
 drivers/firewire/ohci.c             | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----------------------------------------------------------------------------
 include/linux/firewire.h            |  12 ++++++++++--
 7 files changed, 146 insertions(+), 116 deletions(-)


Regards

Takashi Sakamoto