drm/ttm: move the LRU into resource handling v4

This way we finally fix the problem that new resource are
not immediately evict-able after allocation.

That has caused numerous problems including OOM on GDS handling
and not being able to use TTM as general resource manager.

v2: stop assuming in ttm_resource_fini that res->bo is still valid.
v3: cleanup kerneldoc, add more lockdep annotation
v4: consistently use res->num_pages

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220321132601.2161-1-christian.koenig@amd.com

4 files changed, 159 insertions, 147 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index db3dc7ef5382..cb0fa932d495 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -69,108 +69,16 @@ static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
 	}
 }
 
-static inline void ttm_bo_move_to_pinned(struct ttm_buffer_object *bo)
-{
-	struct ttm_device *bdev = bo->bdev;
-
-	list_move_tail(&bo->lru, &bdev->pinned);
-
-	if (bdev->funcs->del_from_lru_notify)
-		bdev->funcs->del_from_lru_notify(bo);
-}
-
-static inline void ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
-{
-	struct ttm_device *bdev = bo->bdev;
-
-	list_del_init(&bo->lru);
-
-	if (bdev->funcs->del_from_lru_notify)
-		bdev->funcs->del_from_lru_notify(bo);
-}
-
-static void ttm_bo_bulk_move_set_pos(struct ttm_lru_bulk_move_pos *pos,
-				     struct ttm_buffer_object *bo)
-{
-	if (!pos->first)
-		pos->first = bo;
-	pos->last = bo;
-}
-
 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
-			     struct ttm_resource *mem,
 			     struct ttm_lru_bulk_move *bulk)
 {
-	struct ttm_device *bdev = bo->bdev;
-	struct ttm_resource_manager *man;
-
-	if (!bo->deleted)
-		dma_resv_assert_held(bo->base.resv);
-
-	if (bo->pin_count) {
-		ttm_bo_move_to_pinned(bo);
-		return;
-	}
-
-	if (!mem)
-		return;
-
-	man = ttm_manager_type(bdev, mem->mem_type);
-	list_move_tail(&bo->lru, &man->lru[bo->priority]);
-
-	if (bdev->funcs->del_from_lru_notify)
-		bdev->funcs->del_from_lru_notify(bo);
-
-	if (bulk && !bo->pin_count) {
-		switch (bo->resource->mem_type) {
-		case TTM_PL_TT:
-			ttm_bo_bulk_move_set_pos(&bulk->tt[bo->priority], bo);
-			break;
+	dma_resv_assert_held(bo->base.resv);
 
-		case TTM_PL_VRAM:
-			ttm_bo_bulk_move_set_pos(&bulk->vram[bo->priority], bo);
-			break;
-		}
-	}
+	if (bo->resource)
+		ttm_resource_move_to_lru_tail(bo->resource, bulk);
 }
 EXPORT_SYMBOL(ttm_bo_move_to_lru_tail);
 
-void ttm_bo_bulk_move_lru_tail(struct ttm_lru_bulk_move *bulk)
-{
-	unsigned i;
-
-	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
-		struct ttm_lru_bulk_move_pos *pos = &bulk->tt[i];
-		struct ttm_resource_manager *man;
-
-		if (!pos->first)
-			continue;
-
-		dma_resv_assert_held(pos->first->base.resv);
-		dma_resv_assert_held(pos->last->base.resv);
-
-		man = ttm_manager_type(pos->first->bdev, TTM_PL_TT);
-		list_bulk_move_tail(&man->lru[i], &pos->first->lru,
-				    &pos->last->lru);
-	}
-
-	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
-		struct ttm_lru_bulk_move_pos *pos = &bulk->vram[i];
-		struct ttm_resource_manager *man;
-
-		if (!pos->first)
-			continue;
-
-		dma_resv_assert_held(pos->first->base.resv);
-		dma_resv_assert_held(pos->last->base.resv);
-
-		man = ttm_manager_type(pos->first->bdev, TTM_PL_VRAM);
-		list_bulk_move_tail(&man->lru[i], &pos->first->lru,
-				    &pos->last->lru);
-	}
-}
-EXPORT_SYMBOL(ttm_bo_bulk_move_lru_tail);
-
 static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
 				  struct ttm_resource *mem, bool evict,
 				  struct ttm_operation_ctx *ctx,
@@ -344,7 +252,6 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
 		return ret;
 	}
 
-	ttm_bo_move_to_pinned(bo);
 	list_del_init(&bo->ddestroy);
 	spin_unlock(&bo->bdev->lru_lock);
 	ttm_bo_cleanup_memtype_use(bo);
@@ -445,7 +352,7 @@ static void ttm_bo_release(struct kref *kref)
 		 */
 		if (bo->pin_count) {
 			bo->pin_count = 0;
-			ttm_bo_move_to_lru_tail(bo, bo->resource, NULL);
+			ttm_resource_move_to_lru_tail(bo->resource, NULL);
 		}
 
 		kref_init(&bo->kref);
@@ -458,7 +365,6 @@ static void ttm_bo_release(struct kref *kref)
 	}
 
 	spin_lock(&bo->bdev->lru_lock);
-	ttm_bo_del_from_lru(bo);
 	list_del(&bo->ddestroy);
 	spin_unlock(&bo->bdev->lru_lock);
 
@@ -673,15 +579,17 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
 			struct ww_acquire_ctx *ticket)
 {
 	struct ttm_buffer_object *bo = NULL, *busy_bo = NULL;
+	struct ttm_resource *res;
 	bool locked = false;
 	unsigned i;
 	int ret;
 
 	spin_lock(&bdev->lru_lock);
 	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
-		list_for_each_entry(bo, &man->lru[i], lru) {
+		list_for_each_entry(res, &man->lru[i], lru) {
 			bool busy;
 
+			bo = res->bo;
 			if (!ttm_bo_evict_swapout_allowable(bo, ctx, place,
 							    &locked, &busy)) {
 				if (busy && !busy_bo && ticket !=
@@ -699,7 +607,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
 		}
 
 		/* If the inner loop terminated early, we have our candidate */
-		if (&bo->lru != &man->lru[i])
+		if (&res->lru != &man->lru[i])
 			break;
 
 		bo = NULL;
@@ -875,9 +783,6 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 	}
 
 error:
-	if (bo->resource->mem_type == TTM_PL_SYSTEM && !bo->pin_count)
-		ttm_bo_move_to_lru_tail_unlocked(bo);
-
 	return ret;
 }
 EXPORT_SYMBOL(ttm_bo_mem_space);
@@ -971,7 +876,6 @@ int ttm_bo_init_reserved(struct ttm_device *bdev,
 	bo->destroy = destroy ? destroy : ttm_bo_default_destroy;
 
 	kref_init(&bo->kref);
-	INIT_LIST_HEAD(&bo->lru);
 	INIT_LIST_HEAD(&bo->ddestroy);
 	bo->bdev = bdev;
 	bo->type = type;
@@ -1021,8 +925,6 @@ int ttm_bo_init_reserved(struct ttm_device *bdev,
 		return ret;
 	}
 
-	ttm_bo_move_to_lru_tail_unlocked(bo);
-
 	return ret;
 }
 EXPORT_SYMBOL(ttm_bo_init_reserved);
@@ -1123,7 +1025,6 @@ int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
 		return ret == -EBUSY ? -ENOSPC : ret;
 	}
 
-	ttm_bo_move_to_pinned(bo);
 	/* TODO: Cleanup the locking */
 	spin_unlock(&bo->bdev->lru_lock);
 
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 544a84fa6589..0163e92b57af 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -231,7 +231,6 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
 
 	atomic_inc(&ttm_glob.bo_count);
 	INIT_LIST_HEAD(&fbo->base.ddestroy);
-	INIT_LIST_HEAD(&fbo->base.lru);
 	fbo->base.moving = NULL;
 	drm_vma_node_reset(&fbo->base.base.vma_node);
 
diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
index be24bb6cefd0..ba35887147ba 100644
--- a/drivers/gpu/drm/ttm/ttm_device.c
+++ b/drivers/gpu/drm/ttm/ttm_device.c
@@ -144,6 +144,7 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
 {
 	struct ttm_resource_manager *man;
 	struct ttm_buffer_object *bo;
+	struct ttm_resource *res;
 	unsigned i, j;
 	int ret;
 
@@ -154,8 +155,11 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
 			continue;
 
 		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j) {
-			list_for_each_entry(bo, &man->lru[j], lru) {
-				uint32_t num_pages = PFN_UP(bo->base.size);
+			list_for_each_entry(res, &man->lru[j], lru) {
+				uint32_t num_pages;
+
+				bo = res->bo;
+				num_pages = PFN_UP(bo->base.size);
 
 				ret = ttm_bo_swapout(bo, ctx, gfp_flags);
 				/* ttm_bo_swapout has dropped the lru_lock */
@@ -259,49 +263,45 @@ void ttm_device_fini(struct ttm_device *bdev)
 }
 EXPORT_SYMBOL(ttm_device_fini);
 
-void ttm_device_clear_dma_mappings(struct ttm_device *bdev)
+static void ttm_device_clear_lru_dma_mappings(struct ttm_device *bdev,
+					      struct list_head *list)
 {
-	struct ttm_resource_manager *man;
-	struct ttm_buffer_object *bo;
-	unsigned int i, j;
+	struct ttm_resource *res;
 
 	spin_lock(&bdev->lru_lock);
-	while (!list_empty(&bdev->pinned)) {
-		bo = list_first_entry(&bdev->pinned, struct ttm_buffer_object, lru);
+	while ((res = list_first_entry_or_null(list, typeof(*res), lru))) {
+		struct ttm_buffer_object *bo = res->bo;
+
 		/* Take ref against racing releases once lru_lock is unlocked */
-		if (ttm_bo_get_unless_zero(bo)) {
-			list_del_init(&bo->lru);
-			spin_unlock(&bdev->lru_lock);
+		if (!ttm_bo_get_unless_zero(bo))
+			continue;
 
-			if (bo->ttm)
-				ttm_tt_unpopulate(bo->bdev, bo->ttm);
+		list_del_init(&res->lru);
+		spin_unlock(&bdev->lru_lock);
 
-			ttm_bo_put(bo);
-			spin_lock(&bdev->lru_lock);
-		}
+		if (bo->ttm)
+			ttm_tt_unpopulate(bo->bdev, bo->ttm);
+
+		ttm_bo_put(bo);
+		spin_lock(&bdev->lru_lock);
 	}
+	spin_unlock(&bdev->lru_lock);
+}
+
+void ttm_device_clear_dma_mappings(struct ttm_device *bdev)
+{
+	struct ttm_resource_manager *man;
+	unsigned int i, j;
+
+	ttm_device_clear_lru_dma_mappings(bdev, &bdev->pinned);
 
 	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
 		man = ttm_manager_type(bdev, i);
 		if (!man || !man->use_tt)
 			continue;
 
-		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j) {
-			while (!list_empty(&man->lru[j])) {
-				bo = list_first_entry(&man->lru[j], struct ttm_buffer_object, lru);
-				if (ttm_bo_get_unless_zero(bo)) {
-					list_del_init(&bo->lru);
-					spin_unlock(&bdev->lru_lock);
-
-					if (bo->ttm)
-						ttm_tt_unpopulate(bo->bdev, bo->ttm);
-
-					ttm_bo_put(bo);
-					spin_lock(&bdev->lru_lock);
-				}
-			}
-		}
+		for (j = 0; j < TTM_MAX_BO_PRIORITY; ++j)
+			ttm_device_clear_lru_dma_mappings(bdev, &man->lru[j]);
 	}
-	spin_unlock(&bdev->lru_lock);
 }
 EXPORT_SYMBOL(ttm_device_clear_dma_mappings);
diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index cbd47a104962..2b76ecdf12e8 100644
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -30,12 +30,116 @@
 #include <drm/ttm/ttm_bo_driver.h>
 
 /**
+ * ttm_lru_bulk_move_init - initialize a bulk move structure
+ * @bulk: the structure to init
+ *
+ * For now just memset the structure to zero.
+ */
+void ttm_lru_bulk_move_init(struct ttm_lru_bulk_move *bulk)
+{
+	memset(bulk, 0, sizeof(*bulk));
+}
+EXPORT_SYMBOL(ttm_lru_bulk_move_init);
+
+/**
+ * ttm_lru_bulk_move_tail - bulk move range of resources to the LRU tail.
+ *
+ * @bulk: bulk move structure
+ *
+ * Bulk move BOs to the LRU tail, only valid to use when driver makes sure that
+ * resource order never changes. Should be called with &ttm_device.lru_lock held.
+ */
+void ttm_lru_bulk_move_tail(struct ttm_lru_bulk_move *bulk)
+{
+	unsigned i;
+
+	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
+		struct ttm_lru_bulk_move_pos *pos = &bulk->tt[i];
+		struct ttm_resource_manager *man;
+
+		if (!pos->first)
+			continue;
+
+		lockdep_assert_held(&pos->first->bo->bdev->lru_lock);
+		dma_resv_assert_held(pos->first->bo->base.resv);
+		dma_resv_assert_held(pos->last->bo->base.resv);
+
+		man = ttm_manager_type(pos->first->bo->bdev, TTM_PL_TT);
+		list_bulk_move_tail(&man->lru[i], &pos->first->lru,
+				    &pos->last->lru);
+	}
+
+	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
+		struct ttm_lru_bulk_move_pos *pos = &bulk->vram[i];
+		struct ttm_resource_manager *man;
+
+		if (!pos->first)
+			continue;
+
+		lockdep_assert_held(&pos->first->bo->bdev->lru_lock);
+		dma_resv_assert_held(pos->first->bo->base.resv);
+		dma_resv_assert_held(pos->last->bo->base.resv);
+
+		man = ttm_manager_type(pos->first->bo->bdev, TTM_PL_VRAM);
+		list_bulk_move_tail(&man->lru[i], &pos->first->lru,
+				    &pos->last->lru);
+	}
+}
+EXPORT_SYMBOL(ttm_lru_bulk_move_tail);
+
+/* Record a resource position in a bulk move structure */
+static void ttm_lru_bulk_move_set_pos(struct ttm_lru_bulk_move_pos *pos,
+				      struct ttm_resource *res)
+{
+	if (!pos->first)
+		pos->first = res;
+	pos->last = res;
+}
+
+/* Move a resource to the LRU tail and track the bulk position */
+void ttm_resource_move_to_lru_tail(struct ttm_resource *res,
+				   struct ttm_lru_bulk_move *bulk)
+{
+	struct ttm_buffer_object *bo = res->bo;
+	struct ttm_device *bdev = bo->bdev;
+	struct ttm_resource_manager *man;
+
+	lockdep_assert_held(&bo->bdev->lru_lock);
+
+	if (bo->pin_count) {
+		list_move_tail(&res->lru, &bdev->pinned);
+		if (bdev->funcs->del_from_lru_notify)
+			bdev->funcs->del_from_lru_notify(res->bo);
+		return;
+	}
+
+	man = ttm_manager_type(bdev, res->mem_type);
+	list_move_tail(&res->lru, &man->lru[bo->priority]);
+
+	if (bdev->funcs->del_from_lru_notify)
+		bdev->funcs->del_from_lru_notify(bo);
+
+	if (!bulk)
+		return;
+
+	switch (res->mem_type) {
+	case TTM_PL_TT:
+		ttm_lru_bulk_move_set_pos(&bulk->tt[bo->priority], res);
+		break;
+
+	case TTM_PL_VRAM:
+		ttm_lru_bulk_move_set_pos(&bulk->vram[bo->priority], res);
+		break;
+	}
+}
+
+/**
  * ttm_resource_init - resource object constructure
  * @bo: buffer object this resources is allocated for
  * @place: placement of the resource
  * @res: the resource object to inistilize
  *
- * Initialize a new resource object. Counterpart of &ttm_resource_fini.
+ * Initialize a new resource object. Counterpart of ttm_resource_fini().
  */
 void ttm_resource_init(struct ttm_buffer_object *bo,
                        const struct ttm_place *place,
@@ -52,10 +156,12 @@ void ttm_resource_init(struct ttm_buffer_object *bo,
 	res->bus.is_iomem = false;
 	res->bus.caching = ttm_cached;
 	res->bo = bo;
+	INIT_LIST_HEAD(&res->lru);
 
 	man = ttm_manager_type(bo->bdev, place->mem_type);
 	spin_lock(&bo->bdev->lru_lock);
-	man->usage += bo->base.size;
+	man->usage += res->num_pages << PAGE_SHIFT;
+	ttm_resource_move_to_lru_tail(res, NULL);
 	spin_unlock(&bo->bdev->lru_lock);
 }
 EXPORT_SYMBOL(ttm_resource_init);
@@ -66,15 +172,21 @@ EXPORT_SYMBOL(ttm_resource_init);
  * @res: the resource to clean up
  *
  * Should be used by resource manager backends to clean up the TTM resource
- * objects before freeing the underlying structure. Counterpart of
- * &ttm_resource_init
+ * objects before freeing the underlying structure. Makes sure the resource is
+ * removed from the LRU before destruction.
+ * Counterpart of ttm_resource_init().
  */
 void ttm_resource_fini(struct ttm_resource_manager *man,
 		       struct ttm_resource *res)
 {
-	spin_lock(&man->bdev->lru_lock);
-	man->usage -= res->bo->base.size;
-	spin_unlock(&man->bdev->lru_lock);
+	struct ttm_device *bdev = man->bdev;
+
+	spin_lock(&bdev->lru_lock);
+	list_del_init(&res->lru);
+	if (res->bo && bdev->funcs->del_from_lru_notify)
+		bdev->funcs->del_from_lru_notify(res->bo);
+	man->usage -= res->num_pages << PAGE_SHIFT;
+	spin_unlock(&bdev->lru_lock);
 }
 EXPORT_SYMBOL(ttm_resource_fini);