drm/amdkfd: Fix lock dependency warning with srcu

In the Linux kernel, the following vulnerability has been resolved:

drm/amdkfd: Fix lock dependency warning with srcu

======================================================

WARNING: possible circular locking dependency detected

6.5.0-kfd-yangp #2289 Not tainted

------------------------------------------------------

kworker/0:2/996 is trying to acquire lock:

(srcu){.+.+}-{0:0}, at: __synchronize_srcu+0x5/0x1a0

but task is already holding lock:

((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}, at:

process_one_work+0x211/0x560

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}:

__flush_work+0x88/0x4f0

svm_range_list_lock_and_flush_work+0x3d/0x110 [amdgpu]

svm_range_set_attr+0xd6/0x14c0 [amdgpu]

kfd_ioctl+0x1d1/0x630 [amdgpu]

__x64_sys_ioctl+0x88/0xc0

-> #2 (&info->lock#2){+.+.}-{3:3}:

__mutex_lock+0x99/0xc70

amdgpu_amdkfd_gpuvm_restore_process_bos+0x54/0x740 [amdgpu]

restore_process_helper+0x22/0x80 [amdgpu]

restore_process_worker+0x2d/0xa0 [amdgpu]

process_one_work+0x29b/0x560

worker_thread+0x3d/0x3d0

-> #1 ((work_completion)(&(&process->restore_work)->work)){+.+.}-{0:0}:

__flush_work+0x88/0x4f0

__cancel_work_timer+0x12c/0x1c0

kfd_process_notifier_release_internal+0x37/0x1f0 [amdgpu]

__mmu_notifier_release+0xad/0x240

exit_mmap+0x6a/0x3a0

mmput+0x6a/0x120

do_exit+0x322/0xb90

do_group_exit+0x37/0xa0

__x64_sys_exit_group+0x18/0x20

do_syscall_64+0x38/0x80

-> #0 (srcu){.+.+}-{0:0}:

__lock_acquire+0x1521/0x2510

lock_sync+0x5f/0x90

__synchronize_srcu+0x4f/0x1a0

__mmu_notifier_release+0x128/0x240

exit_mmap+0x6a/0x3a0

mmput+0x6a/0x120

svm_range_deferred_list_work+0x19f/0x350 [amdgpu]

process_one_work+0x29b/0x560

worker_thread+0x3d/0x3d0

other info that might help us debug this:

Chain exists of:

srcu --> &info->lock#2 --> (work_completion)(&svms->deferred_list_work)

Possible unsafe locking scenario:

CPU0 CPU1

---- ----

lock((work_completion)(&svms->deferred_list_work));

lock(&info->lock#2);

lock((work_completion)(&svms->deferred_list_work));

sync(srcu);