When detecting updates of bus topology, the data of fw_device is newly
allocated and caches the content of configuration ROM from the
corresponding node. Then, the tree of device is sought to find the
previous data of fw_device corresponding to the node. If found, the
previous data is updated and reused and the data of fw_device newly
allocated is going to be released.

The above procedure is done in the call of device_find_child(), however it
is a bit abusing against the intention of the helper function, since it is
preferable to find only without updating.

This commit splits the update outside of the call.

Cc: Zijun Hu <zijun_hu@icloud.com>
Link: https://lore.kernel.org/r/20240820132132.28839-1-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

A commit 404957c1e207 ("firewire: ohci: use guard macro to serialize
accesses to phy registers") refactored initiated_reset() helper function,
while the error path was changed wrongly.

This commit fixes the bug.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 80f3401dfeb2 ("firewire: ohci: use guard macro to serialize accesses to phy registers")
Link: https://lore.kernel.org/r/20240817091128.180303-1-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The size of space for configuration ROM is defined by IEEE 1212. The start
and end offsets are available as some macros in UAPI header.

This commit uses these macros to compute the size.

Link: https://lore.kernel.org/r/20240814131222.69949-4-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The ohci_info() macro is a thin wrapper of dev_info(), while it is never
used.

Link: https://lore.kernel.org/r/20240814131222.69949-3-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The __aligned() macro has been available since v4.19 kernel by a commit
815f0ddb ("include/linux/compiler*.h: make compiler-*.h mutually
exclusive").

This commit replaces with the macro.

Link: https://lore.kernel.org/r/20240814131222.69949-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

In core function, the instances of some client resource structures are
maintained by IDR. As of kernel v6.0, IDR has been superseded by XArray
and deprecated.

This commit replaces the usage of IDR with XArray to maintain the
resource instances. The instance of XArray is allocated per client with
XA_FLAGS_ALLOC1 so that the index of allocated entry is greater than zero
and returns to user space client as handle of the resource.

Link: https://lore.kernel.org/r/20240812235210.28458-6-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

firewire: core: code refactoring to use idr_for_each_entry() macro instead of idr_for_each() function

This commit is a preparation to use xa_for_each() macro. Current
implementation uses idr_for_each() function and has a disadvantage to
replace with the macro. The IDR framework has idr_for_each_entry() macro
for the similar purpose. This commit replace the function with the
macro with minor code refactoring.

Link: https://lore.kernel.org/r/20240812235210.28458-5-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

It depends on the function assigned to release member to identify
resource structure.

This commit adds a helper function to identify iso_resource structure.

Link: https://lore.kernel.org/r/20240812235210.28458-4-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

All of local resource structure commonly have data of client_resource type
in its first member. This design sometimes requires usage of
container_of to retrieve parent structure by the first member.

This commit adds some helper functions for this purpose.

Link: https://lore.kernel.org/r/20240812235210.28458-3-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

Current implementation checks and validates the result to find resource
entry two times. It is redundant.

This commit refactors the redundancy.

Link: https://lore.kernel.org/r/20240812235210.28458-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The data of XArray structure includes spinlock and requires no external
lock, while the data is still under the critical section by
fw_device_rwsem.

This commit deletes the critical section.

Link: https://lore.kernel.org/r/20240812014251.165492-3-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

In core function, the instances of fw_device corresponding to firewire device
node in system are maintained by IDR. As of kernel v6.0, IDR has been
superseded by XArray and deprecated.

This commit replaces the usage of IDR with XArray to maintain the device
instances. The instance of XArray is allocated statically, and
initialized with XA_FLAGS_ALLOC so that the index of allocated entry starts
with zero and available as the minor identifier of device node.

Link: https://lore.kernel.org/r/20240812014251.165492-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

A commit d8527cab ("firewire: cdev: implement new event to notify
response subaction with time stamp") adds an additional case,
FW_CDEV_EVENT_RESPONSE2, into switch statement in complete_transaction().
However, the range of block is beyond to the case label and reaches
neibour default label.

This commit corrects the range of block. Fortunately, it has few impacts
in practice since the local variable in the scope under the label is not
used in codes under default label.

Fixes: d8527cab ("firewire: cdev: implement new event to notify response subaction with time stamp")
Link: https://lore.kernel.org/r/20240810070403.36801-1-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI driver uses spinlock to serialize operations for
isochronous contexts.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-18-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI driver uses spinlock for the process to update local
configuration ROM.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-17-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI driver maintains bus time to respond to querying request.
The concurrent access to the bus time is protected by spinlock.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-16-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core functions uses spinlock in instance of fw_card structure to
protect concurrent access to properties in the instance.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-15-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function maintains pending asynchronous transactions by list in
the instance of fw_card. The concurrent access to the list is protected
by spinlock in the instance.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-14-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function maintains clients to receive phy configuration packets
by list in the instance of fw_card. The concurrent access to the list is
protected by spinlock in the instance.

This commit uses guard macro to maintain the list.

Link: https://lore.kernel.org/r/20240805085408.251763-13-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function allows one isochronous contexts per userspace client.
The concurrent access to the context is protected by spinlock in the
instance of client.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-12-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function provides UAPI to maintain isochronous resources allocated
by userspace clients across bus resets automatically. The resources are
maintained by IDR and the concurrent access to it is protected by spinlock
in the instance of client.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-11-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function maintains events to userspace by list in the instance of
client. The concurrent access to the list is protected by spinlock in
the instance.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-10-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function provides an operation for userspace application to
retrieve current value of CYCLE_TIMER register with several types of
system time. In the operation, local interrupt is disables so that the
access of the register and ktime are done atomically.

This commit uses guard macro to disable/enable local interrupts.

Link: https://lore.kernel.org/r/20240805085408.251763-9-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function maintains address handlers by list. It is protected by
spinlock to insert and remove entry to the list.

This commit uses guard macro to maintain the spinlock.

Link: https://lore.kernel.org/r/20240805085408.251763-8-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function maintains the instance of fw_device structure by IDR.
The concurrent access to IDR is protected by static read/write semaphore.
The semaphore is also utilized to protect concurrent access to the
content of configuration ROM cached to the instance so that the cache is
swapped to the latest one.

This commit uses guard macro to maintain the mutex.

Link: https://lore.kernel.org/r/20240805085408.251763-7-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function maintains address handlers by list. RCU is utilized
for efficient read access to any entries in the list.

This commit uses guard macro to maintain RCU locking and releasing.

Link: https://lore.kernel.org/r/20240805085408.251763-6-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The 1394 OHCI driver protects concurrent accesses to phy registers by
mutex object in fw_ohci structure.

This commit uses guard macro to maintain the mutex.

Link: https://lore.kernel.org/r/20240805085408.251763-5-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function maintains userspace clients by the list in fw_device
object associated to the operated character device. The concurrent
access to the list is protected by mutex in the object.

This commit uses guard macro to maintain the mutex.

Link: https://lore.kernel.org/r/20240805085408.251763-4-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function maintains registered cards by list. The concurrent
access to the list is protected by static mutex.

This commit uses guard macro to maintain the mutex.

Link: https://lore.kernel.org/r/20240805085408.251763-3-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The core function provide a kernel API to send phy configuration packet.
Current implementation of the feature uses packet object allocated
statically. The concurrent access to the object is protected by static
mutex.

This commit uses guard macro to maintain the mutex.

Link: https://lore.kernel.org/r/20240805085408.251763-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

THis commit replaces current implementation with the helper functions added
in the former commit.

Link: https://lore.kernel.org/r/20240802003606.109402-5-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

In 1394 OHCI specification, the format of data for IT DMA is different from
the format of isochronous packet in IEEE 1394 specification, in its spd and
srcBusID fields.

This commit adds some static inline functions to serialize/deserialize the
data of IT DMA.

Link: https://lore.kernel.org/r/20240802003606.109402-4-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

This commit replaces current implementation with the helper functions added
in the former commit.

Link: https://lore.kernel.org/r/20240802003606.109402-3-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

In 1394 OHCI specification, the format of data for AT DMA is different from
the format of asynchronous packet in IEEE 1394 specification, in its spd
and srcBusID fields.

This commit adds some static inline functions to serialize/deserialize the
data of AT DMA.

Link: https://lore.kernel.org/r/20240802003606.109402-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

Current implementation directly uses refcount_t to maintain the life time
of fw_node, while kref is available for the same purpose.

This commit replaces the implementation with kref.

Link: https://lore.kernel.org/r/20240801022629.31857-1-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

A common helper function is available to serialize the first quadlet of phy
configuration packet.

This commit is for the purpose.

Link: https://lore.kernel.org/r/20240729134631.127189-4-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The string table for tcode is just used by log_ar_at_event(). In the case,
it is suitable to move the table inner the function definition.

This commit is for the purpose. Additionally, the hard-coded value for
tcode is replaced with defined macros as many as possible.

Link: https://lore.kernel.org/r/20240729134631.127189-3-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

In IEEE 1394 specification, 0x0e in tcode field is reserved for internal
purpose depending on link layer. In 1394 OHCI specification, it is used to
express phy packet in AT/AR contexts.

Current implementation of 1394 OHCI driver has several macros for the code.
They can be simply replaced with a macro in core code.

This commit obsoletes the macros.

Link: https://lore.kernel.org/r/20240729134631.127189-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

The kernel sleep profile is no longer working due to a recursive locking
bug introduced by commit 42a20f86 ("sched: Add wrapper for get_wchan()
to keep task blocked")

Booting with the 'profile=sleep' kernel command line option added or
executing

  # echo -n sleep > /sys/kernel/profiling

after boot causes the system to lock up.

Lockdep reports

  kthreadd/3 is trying to acquire lock:
  ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: get_wchan+0x32/0x70

  but task is already holding lock:
  ffff93ac82e08d58 (&p->pi_lock){....}-{2:2}, at: try_to_wake_up+0x53/0x370

with the call trace being

   lock_acquire+0xc8/0x2f0
   get_wchan+0x32/0x70
   __update_stats_enqueue_sleeper+0x151/0x430
   enqueue_entity+0x4b0/0x520
   enqueue_task_fair+0x92/0x6b0
   ttwu_do_activate+0x73/0x140
   try_to_wake_up+0x213/0x370
   swake_up_locked+0x20/0x50
   complete+0x2f/0x40
   kthread+0xfb/0x180

However, since nobody noticed this regression for more than two years,
let's remove 'profile=sleep' support based on the assumption that nobody
needs this functionality.

Fixes: 42a20f86 ("sched: Add wrapper for get_wchan() to keep task blocked")
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>