Arm FF-A fixes for v6.16
Couple of fixes to address:
1. The safety and memory issues in the FF-A notification callback handler:
The fixes replaces a mutex with an rwlock to prevent sleeping in atomic
context, resolving kernel warnings. Memory allocation is moved outside
the lock to support this transition safely. Additionally, a memory leak
in the notifier unregistration path is fixed by properly freeing the
callback node.
2. The missing entry in struct ffa_indirect_msg_hdr:
The fix adds the missing 32 bit reserved entry in the structure as
required by the FF-A specification.
* tag 'ffa-fixes-6.16' of https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
firmware: arm_ffa: Fix the missing entry in struct ffa_indirect_msg_hdr
firmware: arm_ffa: Replace mutex with rwlock to avoid sleep in atomic context
firmware: arm_ffa: Move memory allocation outside the mutex locking
firmware: arm_ffa: Fix memory leak by freeing notifier callback node
Link: https://lore.kernel.org/r/20250609105207.1185570-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>