[PATCH AUTOSEL 6.0 39/44] drm/amdgpu: Drop eviction lock when allocating PT BO

From: Sasha Levin
Date: Fri Nov 18 2022 - 21:17:26 EST


From: Philip Yang <Philip.Yang@xxxxxxx>

[ Upstream commit e034a0d9aaee5c9129d5dfdfdfcab988a953412d ]

Re-take the eviction lock immediately again after the allocation is
completed, to fix circular locking warning with drm_buddy allocator.

Move amdgpu_vm_eviction_lock/unlock/trylock to amdgpu_vm.h as they are
called from multiple files.

Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 26 -----------------------
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 26 +++++++++++++++++++++++
drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c | 2 ++
3 files changed, 28 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 04130f8813ef..369c0d03e3c6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -143,32 +143,6 @@ int amdgpu_vm_set_pasid(struct amdgpu_device *adev, struct amdgpu_vm *vm,
return 0;
}

-/*
- * vm eviction_lock can be taken in MMU notifiers. Make sure no reclaim-FS
- * happens while holding this lock anywhere to prevent deadlocks when
- * an MMU notifier runs in reclaim-FS context.
- */
-static inline void amdgpu_vm_eviction_lock(struct amdgpu_vm *vm)
-{
- mutex_lock(&vm->eviction_lock);
- vm->saved_flags = memalloc_noreclaim_save();
-}
-
-static inline int amdgpu_vm_eviction_trylock(struct amdgpu_vm *vm)
-{
- if (mutex_trylock(&vm->eviction_lock)) {
- vm->saved_flags = memalloc_noreclaim_save();
- return 1;
- }
- return 0;
-}
-
-static inline void amdgpu_vm_eviction_unlock(struct amdgpu_vm *vm)
-{
- memalloc_noreclaim_restore(vm->saved_flags);
- mutex_unlock(&vm->eviction_lock);
-}
-
/**
* amdgpu_vm_bo_evicted - vm_bo is evicted
*
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 9ecb7f663e19..1f3599363481 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -488,4 +488,30 @@ static inline uint64_t amdgpu_vm_tlb_seq(struct amdgpu_vm *vm)
return atomic64_read(&vm->tlb_seq);
}

+/*
+ * vm eviction_lock can be taken in MMU notifiers. Make sure no reclaim-FS
+ * happens while holding this lock anywhere to prevent deadlocks when
+ * an MMU notifier runs in reclaim-FS context.
+ */
+static inline void amdgpu_vm_eviction_lock(struct amdgpu_vm *vm)
+{
+ mutex_lock(&vm->eviction_lock);
+ vm->saved_flags = memalloc_noreclaim_save();
+}
+
+static inline bool amdgpu_vm_eviction_trylock(struct amdgpu_vm *vm)
+{
+ if (mutex_trylock(&vm->eviction_lock)) {
+ vm->saved_flags = memalloc_noreclaim_save();
+ return true;
+ }
+ return false;
+}
+
+static inline void amdgpu_vm_eviction_unlock(struct amdgpu_vm *vm)
+{
+ memalloc_noreclaim_restore(vm->saved_flags);
+ mutex_unlock(&vm->eviction_lock);
+}
+
#endif
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
index 88de9f0d4728..983899574464 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
@@ -597,7 +597,9 @@ static int amdgpu_vm_pt_alloc(struct amdgpu_device *adev,
if (entry->bo)
return 0;

+ amdgpu_vm_eviction_unlock(vm);
r = amdgpu_vm_pt_create(adev, vm, cursor->level, immediate, &pt);
+ amdgpu_vm_eviction_lock(vm);
if (r)
return r;

--
2.35.1