dma-buf: add more reservation object locking wrappers

Complete the abstraction of the ww_mutex inside the reservation object.

This allows us to add more handling and debugging to the reservation
object in the future.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/320761/

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

@@ -1729,7 +1729,7 @@ int amdgpu_cs_find_mapping(struct amdgpu_cs_parser *parser,
 	*map = mapping;
 
 	/* Double check that the BO is reserved by this CS */
-	if (READ_ONCE((*bo)->tbo.resv->lock.ctx) != &parser->ticket)
+	if (reservation_object_locking_ctx((*bo)->tbo.resv) != &parser->ticket)
 		return -EINVAL;
 
 	if (!((*bo)->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS)) {

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

@@ -380,7 +380,7 @@ amdgpu_gem_prime_import_sg_table(struct drm_device *dev,
 	bp.flags = 0;
 	bp.type = ttm_bo_type_sg;
 	bp.resv = resv;
-	ww_mutex_lock(&resv->lock, NULL);
+	reservation_object_lock(resv, NULL);
 	ret = amdgpu_bo_create(adev, &bp, &bo);
 	if (ret)
 		goto error;
@@ -392,11 +392,11 @@ amdgpu_gem_prime_import_sg_table(struct drm_device *dev,
 	if (attach->dmabuf->ops != &amdgpu_dmabuf_ops)
 		bo->prime_shared_count = 1;
 
-	ww_mutex_unlock(&resv->lock);
+	reservation_object_unlock(resv);
 	return &bo->gem_base;
 
 error:
-	ww_mutex_unlock(&resv->lock);
+	reservation_object_unlock(resv);
 	return ERR_PTR(ret);
 }
 

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

@@ -546,7 +546,7 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
 
 fail_unreserve:
 	if (!bp->resv)
-		ww_mutex_unlock(&bo->tbo.resv->lock);
+		reservation_object_unlock(bo->tbo.resv);
 	amdgpu_bo_unref(&bo);
 	return r;
 }
@@ -1089,7 +1089,7 @@ int amdgpu_bo_set_tiling_flags(struct amdgpu_bo *bo, u64 tiling_flags)
  */
 void amdgpu_bo_get_tiling_flags(struct amdgpu_bo *bo, u64 *tiling_flags)
 {
-	lockdep_assert_held(&bo->tbo.resv->lock.base);
+	reservation_object_assert_held(bo->tbo.resv);
 
 	if (tiling_flags)
 		*tiling_flags = bo->tiling_flags;
@@ -1330,7 +1330,7 @@ int amdgpu_bo_sync_wait(struct amdgpu_bo *bo, void *owner, bool intr)
 u64 amdgpu_bo_gpu_offset(struct amdgpu_bo *bo)
 {
 	WARN_ON_ONCE(bo->tbo.mem.mem_type == TTM_PL_SYSTEM);
-	WARN_ON_ONCE(!ww_mutex_is_locked(&bo->tbo.resv->lock) &&
+	WARN_ON_ONCE(!reservation_object_is_locked(bo->tbo.resv) &&
 		     !bo->pin_count && bo->tbo.type != ttm_bo_type_kernel);
 	WARN_ON_ONCE(bo->tbo.mem.start == AMDGPU_BO_INVALID_OFFSET);
 	WARN_ON_ONCE(bo->tbo.mem.mem_type == TTM_PL_VRAM &&

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

@@ -2416,7 +2416,8 @@ void amdgpu_vm_bo_trace_cs(struct amdgpu_vm *vm, struct ww_acquire_ctx *ticket)
 			struct amdgpu_bo *bo;
 
 			bo = mapping->bo_va->base.bo;
-			if (READ_ONCE(bo->tbo.resv->lock.ctx) != ticket)
+			if (reservation_object_locking_ctx(bo->tbo.resv) !=
+			    ticket)
 				continue;
 		}
 

drivers/gpu/drm/drm_gem.c

@@ -1288,7 +1288,7 @@ retry:
 	if (contended != -1) {
 		struct drm_gem_object *obj = objs[contended];
 
-		ret = ww_mutex_lock_slow_interruptible(&obj->resv->lock,
+		ret = reservation_object_lock_slow_interruptible(obj->resv,
 								 acquire_ctx);
 		if (ret) {
 			ww_acquire_done(acquire_ctx);
@@ -1300,16 +1300,16 @@ retry:
 		if (i == contended)
 			continue;
 
-		ret = ww_mutex_lock_interruptible(&objs[i]->resv->lock,
+		ret = reservation_object_lock_interruptible(objs[i]->resv,
 							    acquire_ctx);
 		if (ret) {
 			int j;
 
 			for (j = 0; j < i; j++)
-				ww_mutex_unlock(&objs[j]->resv->lock);
+				reservation_object_unlock(objs[j]->resv);
 
 			if (contended != -1 && contended >= i)
-				ww_mutex_unlock(&objs[contended]->resv->lock);
+				reservation_object_unlock(objs[contended]->resv);
 
 			if (ret == -EDEADLK) {
 				contended = i;
@@ -1334,7 +1334,7 @@ drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
 	int i;
 
 	for (i = 0; i < count; i++)
-		ww_mutex_unlock(&objs[i]->resv->lock);
+		reservation_object_unlock(objs[i]->resv);
 
 	ww_acquire_fini(acquire_ctx);
 }

drivers/gpu/drm/nouveau/nouveau_prime.c

@@ -68,10 +68,10 @@ struct drm_gem_object *nouveau_gem_prime_import_sg_table(struct drm_device *dev,
 
 	flags = TTM_PL_FLAG_TT;
 
-	ww_mutex_lock(&robj->lock, NULL);
+	reservation_object_lock(robj, NULL);
 	ret = nouveau_bo_new(&drm->client, attach->dmabuf->size, 0, flags, 0, 0,
 			     sg, robj, &nvbo);
-	ww_mutex_unlock(&robj->lock);
+	reservation_object_unlock(robj);
 	if (ret)
 		return ERR_PTR(ret);
 

drivers/gpu/drm/radeon/radeon_object.c

@@ -611,7 +611,7 @@ int radeon_bo_get_surface_reg(struct radeon_bo *bo)
 	int steal;
 	int i;
 
-	lockdep_assert_held(&bo->tbo.resv->lock.base);
+	reservation_object_assert_held(bo->tbo.resv);
 
 	if (!bo->tiling_flags)
 		return 0;
@@ -737,7 +737,7 @@ void radeon_bo_get_tiling_flags(struct radeon_bo *bo,
 				uint32_t *tiling_flags,
 				uint32_t *pitch)
 {
-	lockdep_assert_held(&bo->tbo.resv->lock.base);
+	reservation_object_assert_held(bo->tbo.resv);
 
 	if (tiling_flags)
 		*tiling_flags = bo->tiling_flags;
@@ -749,7 +749,7 @@ int radeon_bo_check_tiling(struct radeon_bo *bo, bool has_moved,
 				bool force_drop)
 {
 	if (!force_drop)
-		lockdep_assert_held(&bo->tbo.resv->lock.base);
+		reservation_object_assert_held(bo->tbo.resv);
 
 	if (!(bo->tiling_flags & RADEON_TILING_SURFACE))
 		return 0;

drivers/gpu/drm/radeon/radeon_prime.c

@@ -68,10 +68,10 @@ struct drm_gem_object *radeon_gem_prime_import_sg_table(struct drm_device *dev,
 	struct radeon_bo *bo;
 	int ret;
 
-	ww_mutex_lock(&resv->lock, NULL);
+	reservation_object_lock(resv, NULL);
 	ret = radeon_bo_create(rdev, attach->dmabuf->size, PAGE_SIZE, false,
 			       RADEON_GEM_DOMAIN_GTT, 0, sg, resv, &bo);
-	ww_mutex_unlock(&resv->lock);
+	reservation_object_unlock(resv);
 	if (ret)
 		return ERR_PTR(ret);
 

drivers/gpu/drm/ttm/ttm_bo.c

@@ -850,8 +850,8 @@ static int ttm_mem_evict_first(struct ttm_bo_device *bdev,
 
 			if (!ttm_bo_evict_swapout_allowable(bo, ctx, &locked,
 							    &busy)) {
-				if (busy && !busy_bo &&
+				if (busy && !busy_bo && ticket !=
-				    bo->resv->lock.ctx != ticket)
+				    reservation_object_locking_ctx(bo->resv))
 					busy_bo = bo;
 				continue;
 			}
@@ -957,8 +957,10 @@ static int ttm_bo_mem_force_space(struct ttm_buffer_object *bo,
 {
 	struct ttm_bo_device *bdev = bo->bdev;
 	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
+	struct ww_acquire_ctx *ticket;
 	int ret;
 
+	ticket = reservation_object_locking_ctx(bo->resv);
 	do {
 		ret = (*man->func->get_node)(man, bo, place, mem);
 		if (unlikely(ret != 0))
@@ -966,7 +968,7 @@ static int ttm_bo_mem_force_space(struct ttm_buffer_object *bo,
 		if (mem->mm_node)
 			break;
 		ret = ttm_mem_evict_first(bdev, mem->mem_type, place, ctx,
-					  bo->resv->lock.ctx);
+					  ticket);
 		if (unlikely(ret != 0))
 			return ret;
 	} while (1);
@@ -1963,7 +1965,7 @@ int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo)
 	ret = mutex_lock_interruptible(&bo->wu_mutex);
 	if (unlikely(ret != 0))
 		return -ERESTARTSYS;
-	if (!ww_mutex_is_locked(&bo->resv->lock))
+	if (!reservation_object_is_locked(bo->resv))
 		goto out_unlock;
 	ret = reservation_object_lock_interruptible(bo->resv, NULL);
 	if (ret == -EINTR)

drivers/gpu/drm/ttm/ttm_execbuf_util.c

@@ -144,10 +144,10 @@ int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
 
 		if (ret == -EDEADLK) {
 			if (intr) {
-				ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
+				ret = reservation_object_lock_slow_interruptible(bo->resv,
 										 ticket);
 			} else {
-				ww_mutex_lock_slow(&bo->resv->lock, ticket);
+				reservation_object_lock_slow(bo->resv, ticket);
 				ret = 0;
 			}
 		}

drivers/gpu/drm/vmwgfx/vmwgfx_blit.c

@@ -459,9 +459,9 @@ int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
 
 	/* Buffer objects need to be either pinned or reserved: */
 	if (!(dst->mem.placement & TTM_PL_FLAG_NO_EVICT))
-		lockdep_assert_held(&dst->resv->lock.base);
+		reservation_object_assert_held(dst->resv);
 	if (!(src->mem.placement & TTM_PL_FLAG_NO_EVICT))
-		lockdep_assert_held(&src->resv->lock.base);
+		reservation_object_assert_held(src->resv);
 
 	if (dst->ttm->state == tt_unpopulated) {
 		ret = dst->ttm->bdev->driver->ttm_tt_populate(dst->ttm, &ctx);

drivers/gpu/drm/vmwgfx/vmwgfx_bo.c

@@ -342,7 +342,7 @@ void vmw_bo_pin_reserved(struct vmw_buffer_object *vbo, bool pin)
 	uint32_t old_mem_type = bo->mem.mem_type;
 	int ret;
 
-	lockdep_assert_held(&bo->resv->lock.base);
+	reservation_object_assert_held(bo->resv);
 
 	if (pin) {
 		if (vbo->pin_count++ > 0)

drivers/gpu/drm/vmwgfx/vmwgfx_cotable.c

@@ -169,7 +169,7 @@ static int vmw_cotable_unscrub(struct vmw_resource *res)
 	} *cmd;
 
 	WARN_ON_ONCE(bo->mem.mem_type != VMW_PL_MOB);
-	lockdep_assert_held(&bo->resv->lock.base);
+	reservation_object_assert_held(bo->resv);
 
 	cmd = VMW_FIFO_RESERVE(dev_priv, sizeof(*cmd));
 	if (!cmd)
@@ -311,7 +311,7 @@ static int vmw_cotable_unbind(struct vmw_resource *res,
 		return 0;
 
 	WARN_ON_ONCE(bo->mem.mem_type != VMW_PL_MOB);
-	lockdep_assert_held(&bo->resv->lock.base);
+	reservation_object_assert_held(bo->resv);
 
 	mutex_lock(&dev_priv->binding_mutex);
 	if (!vcotbl->scrubbed)

drivers/gpu/drm/vmwgfx/vmwgfx_resource.c

@@ -402,14 +402,14 @@ void vmw_resource_unreserve(struct vmw_resource *res,
 
 	if (switch_backup && new_backup != res->backup) {
 		if (res->backup) {
-			lockdep_assert_held(&res->backup->base.resv->lock.base);
+			reservation_object_assert_held(res->backup->base.resv);
 			list_del_init(&res->mob_head);
 			vmw_bo_unreference(&res->backup);
 		}
 
 		if (new_backup) {
 			res->backup = vmw_bo_reference(new_backup);
-			lockdep_assert_held(&new_backup->base.resv->lock.base);
+			reservation_object_assert_held(new_backup->base.resv);
 			list_add_tail(&res->mob_head, &new_backup->res_list);
 		} else {
 			res->backup = NULL;
@@ -691,7 +691,7 @@ void vmw_resource_unbind_list(struct vmw_buffer_object *vbo)
 		.num_shared = 0
 	};
 
-	lockdep_assert_held(&vbo->base.resv->lock.base);
+	reservation_object_assert_held(vbo->base.resv);
 	list_for_each_entry_safe(res, next, &vbo->res_list, mob_head) {
 		if (!res->func->unbind)
 			continue;

include/drm/ttm/ttm_bo_driver.h

@@ -745,10 +745,10 @@ static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
 	WARN_ON(!kref_read(&bo->kref));
 
 	if (interruptible)
-		ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
+		ret = reservation_object_lock_slow_interruptible(bo->resv,
 								 ticket);
 	else
-		ww_mutex_lock_slow(&bo->resv->lock, ticket);
+		reservation_object_lock_slow(bo->resv, ticket);
 
 	if (likely(ret == 0))
 		ttm_bo_del_sub_from_lru(bo);

include/linux/reservation.h

@@ -140,6 +140,38 @@ reservation_object_lock_interruptible(struct reservation_object *obj,
 	return ww_mutex_lock_interruptible(&obj->lock, ctx);
 }
 
+/**
+ * reservation_object_lock_slow - slowpath lock the reservation object
+ * @obj: the reservation object
+ * @ctx: the locking context
+ *
+ * Acquires the reservation object after a die case. This function
+ * will sleep until the lock becomes available. See reservation_object_lock() as
+ * well.
+ */
+static inline void
+reservation_object_lock_slow(struct reservation_object *obj,
+			     struct ww_acquire_ctx *ctx)
+{
+	ww_mutex_lock_slow(&obj->lock, ctx);
+}
+
+/**
+ * reservation_object_lock_slow_interruptible - slowpath lock the reservation
+ * object, interruptible
+ * @obj: the reservation object
+ * @ctx: the locking context
+ *
+ * Acquires the reservation object interruptible after a die case. This function
+ * will sleep until the lock becomes available. See
+ * reservation_object_lock_interruptible() as well.
+ */
+static inline int
+reservation_object_lock_slow_interruptible(struct reservation_object *obj,
+					   struct ww_acquire_ctx *ctx)
+{
+	return ww_mutex_lock_slow_interruptible(&obj->lock, ctx);
+}
 
 /**
  * reservation_object_trylock - trylock the reservation object
@@ -161,6 +193,31 @@ reservation_object_trylock(struct reservation_object *obj)
 	return ww_mutex_trylock(&obj->lock);
 }
 
+/**
+ * reservation_object_is_locked - is the reservation object locked
+ * @obj: the reservation object
+ *
+ * Returns true if the mutex is locked, false if unlocked.
+ */
+static inline bool
+reservation_object_is_locked(struct reservation_object *obj)
+{
+	return ww_mutex_is_locked(&obj->lock);
+}
+
+/**
+ * reservation_object_locking_ctx - returns the context used to lock the object
+ * @obj: the reservation object
+ *
+ * Returns the context used to lock a reservation object or NULL if no context
+ * was used or the object is not locked at all.
+ */
+static inline struct ww_acquire_ctx *
+reservation_object_locking_ctx(struct reservation_object *obj)
+{
+	return READ_ONCE(obj->lock.ctx);
+}
+
 /**
  * reservation_object_unlock - unlock the reservation object
  * @obj: the reservation object