drm/amdgpu: rework synchronization of VM updates v4

If provided we only sync to the BOs reservation
object and no longer to the root PD.

v2: update comment, cleanup amdgpu_bo_sync_wait_resv
v3: use correct reservation object while clearing
v4: fix typo in amdgpu_bo_sync_wait_resv
Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_object.c

@@ -1403,30 +1403,51 @@ void amdgpu_bo_fence(struct amdgpu_bo *bo, struct dma_fence *fence,
 }
 
 /**
- * amdgpu_sync_wait_resv - Wait for BO reservation fences
+ * amdgpu_bo_sync_wait_resv - Wait for BO reservation fences
  *
- * @bo: buffer object
+ * @adev: amdgpu device pointer
+ * @resv: reservation object to sync to
+ * @sync_mode: synchronization mode
  * @owner: fence owner
  * @intr: Whether the wait is interruptible
  *
+ * Extract the fences from the reservation object and waits for them to finish.
+ *
  * Returns:
  * 0 on success, errno otherwise.
  */
-int amdgpu_bo_sync_wait(struct amdgpu_bo *bo, void *owner, bool intr)
+int amdgpu_bo_sync_wait_resv(struct amdgpu_device *adev, struct dma_resv *resv,
+			     enum amdgpu_sync_mode sync_mode, void *owner,
+			     bool intr)
 {
-	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
 	struct amdgpu_sync sync;
 	int r;
 
 	amdgpu_sync_create(&sync);
-	amdgpu_sync_resv(adev, &sync, bo->tbo.base.resv,
-			 AMDGPU_SYNC_NE_OWNER, owner);
+	amdgpu_sync_resv(adev, &sync, resv, sync_mode, owner);
 	r = amdgpu_sync_wait(&sync, intr);
 	amdgpu_sync_free(&sync);
-
 	return r;
 }
 
+/**
+ * amdgpu_bo_sync_wait - Wrapper for amdgpu_bo_sync_wait_resv
+ * @bo: buffer object to wait for
+ * @owner: fence owner
+ * @intr: Whether the wait is interruptible
+ *
+ * Wrapper to wait for fences in a BO.
+ * Returns:
+ * 0 on success, errno otherwise.
+ */
+int amdgpu_bo_sync_wait(struct amdgpu_bo *bo, void *owner, bool intr)
+{
+	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
+
+	return amdgpu_bo_sync_wait_resv(adev, bo->tbo.base.resv,
+					AMDGPU_SYNC_NE_OWNER, owner, intr);
+}
+
 /**
  * amdgpu_bo_gpu_offset - return GPU offset of bo
  * @bo:	amdgpu object for which we query the offset

drivers/gpu/drm/amd/amdgpu/amdgpu_object.h

@@ -277,6 +277,9 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo);
 int amdgpu_bo_fault_reserve_notify(struct ttm_buffer_object *bo);
 void amdgpu_bo_fence(struct amdgpu_bo *bo, struct dma_fence *fence,
 		     bool shared);
+int amdgpu_bo_sync_wait_resv(struct amdgpu_device *adev, struct dma_resv *resv,
+			     enum amdgpu_sync_mode sync_mode, void *owner,
+			     bool intr);
 int amdgpu_bo_sync_wait(struct amdgpu_bo *bo, void *owner, bool intr);
 u64 amdgpu_bo_gpu_offset(struct amdgpu_bo *bo);
 int amdgpu_bo_validate(struct amdgpu_bo *bo);

drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c

@@ -249,13 +249,6 @@ int amdgpu_sync_resv(struct amdgpu_device *adev, struct amdgpu_sync *sync,
 		    owner != AMDGPU_FENCE_OWNER_UNDEFINED)
 			continue;
 
-		/* VM updates only sync with moves but not with user
-		 * command submissions or KFD evictions fences
-		 */
-		if (fence_owner != AMDGPU_FENCE_OWNER_UNDEFINED &&
-		    owner == AMDGPU_FENCE_OWNER_VM)
-			continue;
-
 		/* Ignore fences depending on the sync mode */
 		switch (mode) {
 		case AMDGPU_SYNC_ALWAYS:

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -797,7 +797,7 @@ static int amdgpu_vm_clear_bo(struct amdgpu_device *adev,
 	params.vm = vm;
 	params.direct = direct;
 
-	r = vm->update_funcs->prepare(&params, AMDGPU_FENCE_OWNER_KFD, NULL);
+	r = vm->update_funcs->prepare(&params, NULL, AMDGPU_SYNC_EXPLICIT);
 	if (r)
 		return r;
 
@@ -1293,7 +1293,7 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
 	params.vm = vm;
 	params.direct = direct;
 
-	r = vm->update_funcs->prepare(&params, AMDGPU_FENCE_OWNER_VM, NULL);
+	r = vm->update_funcs->prepare(&params, NULL, AMDGPU_SYNC_EXPLICIT);
 	if (r)
 		return r;
 
@@ -1554,7 +1554,7 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
  * @adev: amdgpu_device pointer
  * @vm: requested vm
  * @direct: direct submission in a page fault
- * @exclusive: fence we need to sync to
+ * @resv: fences we need to sync to
  * @start: start of mapped range
  * @last: last mapped entry
  * @flags: flags for the entries
@@ -1569,14 +1569,14 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
  */
 static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 				       struct amdgpu_vm *vm, bool direct,
-				       struct dma_fence *exclusive,
+				       struct dma_resv *resv,
 				       uint64_t start, uint64_t last,
 				       uint64_t flags, uint64_t addr,
 				       dma_addr_t *pages_addr,
 				       struct dma_fence **fence)
 {
 	struct amdgpu_vm_update_params params;
-	void *owner = AMDGPU_FENCE_OWNER_VM;
+	enum amdgpu_sync_mode sync_mode;
 	int r;
 
 	memset(&params, 0, sizeof(params));
@@ -1585,9 +1585,13 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 	params.direct = direct;
 	params.pages_addr = pages_addr;
 
-	/* sync to everything except eviction fences on unmapping */
+	/* Implicitly sync to command submissions in the same VM before
+	 * unmapping. Sync to moving fences before mapping.
+	 */
 	if (!(flags & AMDGPU_PTE_VALID))
-		owner = AMDGPU_FENCE_OWNER_KFD;
+		sync_mode = AMDGPU_SYNC_EQ_OWNER;
+	else
+		sync_mode = AMDGPU_SYNC_EXPLICIT;
 
 	amdgpu_vm_eviction_lock(vm);
 	if (vm->evicting) {
@@ -1595,7 +1599,7 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 		goto error_unlock;
 	}
 
-	r = vm->update_funcs->prepare(&params, owner, exclusive);
+	r = vm->update_funcs->prepare(&params, resv, sync_mode);
 	if (r)
 		goto error_unlock;
 
@@ -1614,7 +1618,7 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
  * amdgpu_vm_bo_split_mapping - split a mapping into smaller chunks
  *
  * @adev: amdgpu_device pointer
- * @exclusive: fence we need to sync to
+ * @resv: fences we need to sync to
  * @pages_addr: DMA addresses to use for mapping
  * @vm: requested vm
  * @mapping: mapped range and flags to use for the update
@@ -1630,7 +1634,7 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
  * 0 for success, -EINVAL for failure.
  */
 static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
-				      struct dma_fence *exclusive,
+				      struct dma_resv *resv,
 				      dma_addr_t *pages_addr,
 				      struct amdgpu_vm *vm,
 				      struct amdgpu_bo_va_mapping *mapping,
@@ -1706,7 +1710,7 @@ static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
 		}
 
 		last = min((uint64_t)mapping->last, start + max_entries - 1);
-		r = amdgpu_vm_bo_update_mapping(adev, vm, false, exclusive,
+		r = amdgpu_vm_bo_update_mapping(adev, vm, false, resv,
 						start, last, flags, addr,
 						dma_addr, fence);
 		if (r)
@@ -1745,7 +1749,8 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev, struct amdgpu_bo_va *bo_va,
 	dma_addr_t *pages_addr = NULL;
 	struct ttm_mem_reg *mem;
 	struct drm_mm_node *nodes;
-	struct dma_fence *exclusive, **last_update;
+	struct dma_fence **last_update;
+	struct dma_resv *resv;
 	uint64_t flags;
 	struct amdgpu_device *bo_adev = adev;
 	int r;
@@ -1753,7 +1758,7 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev, struct amdgpu_bo_va *bo_va,
 	if (clear || !bo) {
 		mem = NULL;
 		nodes = NULL;
-		exclusive = NULL;
+		resv = vm->root.base.bo->tbo.base.resv;
 	} else {
 		struct ttm_dma_tt *ttm;
 
@@ -1763,7 +1768,7 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev, struct amdgpu_bo_va *bo_va,
 			ttm = container_of(bo->tbo.ttm, struct ttm_dma_tt, ttm);
 			pages_addr = ttm->dma_address;
 		}
-		exclusive = bo->tbo.moving;
+		resv = bo->tbo.base.resv;
 	}
 
 	if (bo) {
@@ -1773,7 +1778,8 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev, struct amdgpu_bo_va *bo_va,
 		flags = 0x0;
 	}
 
-	if (clear || (bo && bo->tbo.base.resv == vm->root.base.bo->tbo.base.resv))
+	if (clear || (bo && bo->tbo.base.resv ==
+		      vm->root.base.bo->tbo.base.resv))
 		last_update = &vm->last_update;
 	else
 		last_update = &bo_va->last_pt_update;
@@ -1787,7 +1793,7 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev, struct amdgpu_bo_va *bo_va,
 	}
 
 	list_for_each_entry(mapping, &bo_va->invalids, list) {
-		r = amdgpu_vm_bo_split_mapping(adev, exclusive, pages_addr, vm,
+		r = amdgpu_vm_bo_split_mapping(adev, resv, pages_addr, vm,
 					       mapping, flags, bo_adev, nodes,
 					       last_update);
 		if (r)
@@ -1982,6 +1988,7 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
 			  struct amdgpu_vm *vm,
 			  struct dma_fence **fence)
 {
+	struct dma_resv *resv = vm->root.base.bo->tbo.base.resv;
 	struct amdgpu_bo_va_mapping *mapping;
 	uint64_t init_pte_value = 0;
 	struct dma_fence *f = NULL;
@@ -1996,7 +2003,7 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
 		    mapping->start < AMDGPU_GMC_HOLE_START)
 			init_pte_value = AMDGPU_PTE_DEFAULT_ATC;
 
-		r = amdgpu_vm_bo_update_mapping(adev, vm, false, NULL,
+		r = amdgpu_vm_bo_update_mapping(adev, vm, false, resv,
 						mapping->start, mapping->last,
 						init_pte_value, 0, NULL, &f);
 		amdgpu_vm_free_mapping(adev, vm, mapping, f);

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h

@@ -227,8 +227,8 @@ struct amdgpu_vm_update_params {
 
 struct amdgpu_vm_update_funcs {
 	int (*map_table)(struct amdgpu_bo *bo);
-	int (*prepare)(struct amdgpu_vm_update_params *p, void * owner,
-		       struct dma_fence *exclusive);
+	int (*prepare)(struct amdgpu_vm_update_params *p, struct dma_resv *resv,
+		       enum amdgpu_sync_mode sync_mode);
 	int (*update)(struct amdgpu_vm_update_params *p,
 		      struct amdgpu_bo *bo, uint64_t pe, uint64_t addr,
 		      unsigned count, uint32_t incr, uint64_t flags);

drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c

@@ -44,26 +44,14 @@ static int amdgpu_vm_cpu_map_table(struct amdgpu_bo *table)
  * Returns:
  * Negativ errno, 0 for success.
  */
-static int amdgpu_vm_cpu_prepare(struct amdgpu_vm_update_params *p, void *owner,
-				 struct dma_fence *exclusive)
+static int amdgpu_vm_cpu_prepare(struct amdgpu_vm_update_params *p,
+				 struct dma_resv *resv,
+				 enum amdgpu_sync_mode sync_mode)
 {
-	int r;
-
-	/* Wait for any BO move to be completed */
-	if (exclusive) {
-		r = dma_fence_wait(exclusive, true);
-		if (unlikely(r))
-			return r;
-	}
-
-	/* Don't wait for submissions during page fault */
-	if (p->direct)
+	if (!resv)
 		return 0;
 
-	/* Wait for PT BOs to be idle. PTs share the same resv. object
-	 * as the root PD BO
-	 */
-	return amdgpu_bo_sync_wait(p->vm->root.base.bo, owner, true);
+	return amdgpu_bo_sync_wait_resv(p->adev, resv, sync_mode, p->vm, true);
 }
 
 /**

drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c

@@ -58,9 +58,9 @@ static int amdgpu_vm_sdma_map_table(struct amdgpu_bo *table)
  * Negativ errno, 0 for success.
  */
 static int amdgpu_vm_sdma_prepare(struct amdgpu_vm_update_params *p,
-				  void *owner, struct dma_fence *exclusive)
+				  struct dma_resv *resv,
+				  enum amdgpu_sync_mode sync_mode)
 {
-	struct amdgpu_bo *root = p->vm->root.base.bo;
 	unsigned int ndw = AMDGPU_VM_SDMA_MIN_NUM_DW;
 	int r;
 
@@ -70,17 +70,10 @@ static int amdgpu_vm_sdma_prepare(struct amdgpu_vm_update_params *p,
 
 	p->num_dw_left = ndw;
 
-	/* Wait for moves to be completed */
-	r = amdgpu_sync_fence(&p->job->sync, exclusive, false);
-	if (r)
-		return r;
-
-	/* Don't wait for any submissions during page fault handling */
-	if (p->direct)
+	if (!resv)
 		return 0;
 
-	return amdgpu_sync_resv(p->adev, &p->job->sync, root->tbo.base.resv,
-				AMDGPU_SYNC_NE_OWNER, owner);
+	return amdgpu_sync_resv(p->adev, &p->job->sync, resv, sync_mode, p->vm);
 }
 
 /**