[PATCH 1/3] drm/ttm: Add range validation function

[Jerome Glisse <jglisse@redhat.com>]

Add a function to validate buffer in a given range of
memory. This is needed by some hw for some of their
buffer (scanout buffer, cursor ...).

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c    |  305 ++++++++++++++++++++++++++++++++++++++-
 include/drm/ttm/ttm_bo_api.h    |    5 +
 include/drm/ttm/ttm_bo_driver.h |    1 +
 3 files changed, 310 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 87c0625..6b0e7e8 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -247,7 +247,6 @@ EXPORT_SYMBOL(ttm_bo_unreserve);
 /*
  * Call bo->mutex locked.
  */
-
 static int ttm_bo_add_ttm(struct ttm_buffer_object *bo, bool zero_alloc)
 {
 	struct ttm_bo_device *bdev = bo->bdev;
@@ -418,6 +417,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
 			kref_put(&bo->list_kref, ttm_bo_ref_bug);
 		}
 		if (bo->mem.mm_node) {
+			bo->mem.mm_node->private = NULL;
 			drm_mm_put_block(bo->mem.mm_node);
 			bo->mem.mm_node = NULL;
 		}
@@ -610,6 +610,7 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, unsigned mem_type,
 
 	spin_lock(&glob->lru_lock);
 	if (evict_mem.mm_node) {
+		evict_mem.mm_node->private = NULL;
 		drm_mm_put_block(evict_mem.mm_node);
 		evict_mem.mm_node = NULL;
 	}
@@ -826,6 +827,7 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 		mem->mm_node = node;
 		mem->mem_type = mem_type;
 		mem->placement = cur_flags;
+		node->private = bo;
 		return 0;
 	}
 
@@ -856,6 +858,7 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 
 		if (ret == 0 && mem->mm_node) {
 			mem->placement = cur_flags;
+			mem->mm_node->private = bo;
 			return 0;
 		}
 
@@ -868,6 +871,173 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 }
 EXPORT_SYMBOL(ttm_bo_mem_space);
 
+static unsigned long ttm_bo_free_size_if_evicted(struct ttm_buffer_object *bo)
+{
+	struct ttm_mem_type_manager *man = &bo->bdev->man[bo->mem.mem_type];
+	struct drm_mm_node *node;
+	unsigned long size;
+
+	size = bo->mem.mm_node->size;
+	if (bo->mem.mm_node->ml_entry.prev != &man->manager.ml_entry) {
+		node = list_entry(bo->mem.mm_node->ml_entry.prev,
+					struct drm_mm_node, ml_entry);
+		if (node->free)
+			size += node->size;
+	}
+	if (bo->mem.mm_node->ml_entry.next != &man->manager.ml_entry) {
+		node = list_entry(bo->mem.mm_node->ml_entry.next,
+					struct drm_mm_node, ml_entry);
+		if (node->free)
+			size += node->size;
+	}
+	return size;
+}
+
+static void ttm_manager_evict_first(struct ttm_buffer_object *bo)
+{
+	struct ttm_mem_type_manager *man = &bo->bdev->man[bo->mem.mem_type];
+	unsigned long free_size_bo, free_size_bo_first;
+	struct ttm_buffer_object *bo_first;
+
+	/* BO is not on lru list, don't add it */
+	if (!list_empty(&bo->lru))
+		return;
+	bo_first = list_first_entry(&man->lru, struct ttm_buffer_object, lru);
+	free_size_bo = ttm_bo_free_size_if_evicted(bo);
+	free_size_bo_first = ttm_bo_free_size_if_evicted(bo_first);
+	if (free_size_bo > free_size_bo_first) {
+		list_del_init(&bo->lru);
+		list_add(&bo->lru, &man->lru);
+	}
+}
+
+static int ttm_manager_space_range(struct ttm_buffer_object *bo,
+					uint32_t mem_type,
+					struct ttm_mem_reg *mem,
+					unsigned long start, unsigned long end,
+					bool interruptible, bool no_wait)
+{
+	struct ttm_bo_global *glob = bo->glob;
+	struct drm_mm_node *entry;
+	struct ttm_mem_type_manager *man = &bo->bdev->man[mem_type];
+	struct drm_mm *mm = &man->manager;
+	unsigned size = end - start;
+	struct ttm_buffer_object *tbo;
+	unsigned wasted;
+	int ret;
+
+	mem->mm_node = NULL;
+	ret = drm_mm_pre_get(&man->manager);
+	if (unlikely(ret))
+		return ret;
+	spin_lock(&glob->lru_lock);
+	list_for_each_entry(entry, &mm->ml_entry, ml_entry) {
+		wasted = 0;
+		if (mem->page_alignment) {
+			unsigned tmp = entry->start % mem->page_alignment;
+			if (tmp)
+				wasted += mem->page_alignment - tmp;
+		}
+		if (entry->start < end && (entry->start+entry->size) > start) {
+			if (!entry->free) {
+				tbo = (struct ttm_buffer_object*)entry->private;
+				ttm_manager_evict_first(tbo);
+			} else {
+				if ((entry->size - wasted) <= size) {
+					/* Found a place */
+					entry = drm_mm_get_block_atomic(entry,
+							mem->num_pages,
+							mem->page_alignment);
+					mem->mm_node = entry;
+					mem->mem_type = mem_type;
+					entry->private = bo;
+					break;
+				}
+			}
+		}
+	}
+	spin_unlock(&glob->lru_lock);
+	return 0;
+}
+
+static int ttm_bo_mem_space_range(struct ttm_buffer_object *bo,
+				uint32_t proposed_placement,
+				struct ttm_mem_reg *mem,
+				unsigned long start, unsigned long end,
+				bool interruptible, bool no_wait)
+{
+	struct ttm_bo_device *bdev = bo->bdev;
+	struct ttm_bo_global *glob = bo->glob;
+	struct ttm_mem_type_manager *man;
+	uint32_t num_prios = bdev->driver->num_mem_type_prio;
+	const uint32_t *prios = bdev->driver->mem_type_prio;
+	uint32_t i;
+	uint32_t mem_type = TTM_PL_SYSTEM;
+	uint32_t cur_flags = 0;
+	bool type_found = false;
+	bool type_ok = false;
+	bool evicted;
+	int ret;
+
+	mem->mm_node = NULL;
+retry:
+	for (i = 0; i < num_prios; ++i) {
+		mem_type = prios[i];
+		man = &bdev->man[mem_type];
+		type_ok = ttm_bo_mt_compatible(man,
+						bo->type == ttm_bo_type_user,
+						mem_type, proposed_placement,
+						&cur_flags);
+		if (!type_ok)
+			continue;
+		if (start > (man->offset + man->size) || end < man->offset)
+			continue;
+		cur_flags = ttm_bo_select_caching(man, bo->mem.placement,
+							cur_flags);
+		if (mem_type == TTM_PL_SYSTEM)
+			break;
+		if (man->has_type && man->use_type) {
+			type_found = true;
+			mem->placement = cur_flags;
+			ret = ttm_manager_space_range(bo, mem_type, mem,
+							start, end,
+							interruptible, no_wait);
+			if (ret)
+				return ret;
+		}
+		if (mem->mm_node)
+			break;
+	}
+	if ((type_ok && (mem_type == TTM_PL_SYSTEM)) || mem->mm_node) {
+		mem->mem_type = mem_type;
+		mem->placement = cur_flags;
+		return 0;
+	}
+	for (i = 0, evicted = false; i < num_prios; ++i) {
+		struct ttm_buffer_object *tmp;
+
+		mem_type = prios[i];
+		man = &bdev->man[mem_type];
+		type_ok = ttm_bo_mt_compatible(man,
+						bo->type == ttm_bo_type_user,
+						mem_type, proposed_placement,
+						&cur_flags);
+		if (!type_ok)
+			continue;
+		if (start > (man->offset + man->size) || end < man->offset)
+			continue;
+		spin_lock(&glob->lru_lock);
+		tmp = list_first_entry(&man->lru, struct ttm_buffer_object, lru);
+		spin_unlock(&glob->lru_lock);
+		ret = ttm_bo_evict(tmp, mem_type, interruptible, no_wait);
+		if (unlikely(ret != 0))
+			return ret;
+	}
+	if (!evicted)
+		return -ENOMEM;
+	goto retry;
+}
+
 int ttm_bo_wait_cpu(struct ttm_buffer_object *bo, bool no_wait)
 {
 	int ret = 0;
@@ -925,6 +1095,7 @@ int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 out_unlock:
 	if (ret && mem.mm_node) {
 		spin_lock(&glob->lru_lock);
+		mem.mm_node->private = NULL;
 		drm_mm_put_block(mem.mm_node);
 		spin_unlock(&glob->lru_lock);
 	}
@@ -998,6 +1169,137 @@ int ttm_buffer_object_validate(struct ttm_buffer_object *bo,
 }
 EXPORT_SYMBOL(ttm_buffer_object_validate);
 
+int ttm_bo_move_buffer_range(struct ttm_buffer_object *bo,
+				uint32_t proposed_placement,
+				unsigned long start, unsigned long end,
+				bool interruptible, bool no_wait)
+{
+	struct ttm_bo_global *glob = bo->glob;
+	int ret = 0;
+	struct ttm_mem_reg mem;
+
+	BUG_ON(!atomic_read(&bo->reserved));
+
+	/*
+	 * FIXME: It's possible to pipeline buffer moves.
+	 * Have the driver move function wait for idle when necessary,
+	 * instead of doing it here.
+	 */
+
+	spin_lock(&bo->lock);
+	ret = ttm_bo_wait(bo, false, interruptible, no_wait);
+	spin_unlock(&bo->lock);
+
+	if (ret)
+		return ret;
+
+	mem.num_pages = bo->num_pages;
+	mem.size = mem.num_pages << PAGE_SHIFT;
+	mem.page_alignment = bo->mem.page_alignment;
+
+	/*
+	 * Determine where to move the buffer.
+	 */
+
+	ret = ttm_bo_mem_space_range(bo, proposed_placement, &mem,
+					start, end, interruptible, no_wait);
+	if (ret)
+		goto out_unlock;
+
+	ret = ttm_bo_handle_move_mem(bo, &mem, false, interruptible, no_wait);
+
+out_unlock:
+	if (ret && mem.mm_node) {
+		spin_lock(&glob->lru_lock);
+		mem.mm_node->private = NULL;
+		drm_mm_put_block(mem.mm_node);
+		spin_unlock(&glob->lru_lock);
+	}
+	return ret;
+}
+
+static int ttm_bo_mem_compat_range(uint32_t proposed_placement,
+					struct ttm_mem_reg *mem,
+					unsigned long start, unsigned long end)
+{
+	if ((proposed_placement & mem->placement & TTM_PL_MASK_MEM) == 0)
+		return 0;
+	if ((proposed_placement & mem->placement & TTM_PL_MASK_CACHING) == 0)
+		return 0;
+	if (mem->mm_node) {
+		unsigned long eend = mem->mm_node->start + mem->mm_node->size;
+		if (mem->mm_node->start < start || eend > end)
+			return 0;
+	}
+
+	return 1;
+}
+
+int ttm_buffer_object_validate_range(struct ttm_buffer_object *bo,
+					uint32_t proposed_placement,
+					unsigned long start, unsigned long end,
+					bool interruptible, bool no_wait)
+{
+	int ret;
+
+	/* Convert to page */
+	start = start >> PAGE_SHIFT;
+	end = end >> PAGE_SHIFT;
+	/* Check that range is valid */
+	if (start > end || (end - start) < bo->num_pages)
+		return -EINVAL;
+
+	BUG_ON(!atomic_read(&bo->reserved));
+	bo->proposed_placement = proposed_placement;
+
+	TTM_DEBUG("Proposed placement 0x%08lx, Old flags 0x%08lx\n",
+		  (unsigned long)proposed_placement,
+		  (unsigned long)bo->mem.placement);
+
+	/*
+	 * Check whether we need to move buffer.
+	 */
+
+	if (!ttm_bo_mem_compat_range(bo->proposed_placement, &bo->mem,
+					start, end)) {
+		ret = ttm_bo_move_buffer_range(bo, bo->proposed_placement,
+						start, end,
+						interruptible, no_wait);
+		if (ret) {
+			if (ret != -ERESTART)
+				printk(KERN_ERR TTM_PFX
+					"Failed moving buffer. "
+					"Proposed placement 0x%08x\n",
+					bo->proposed_placement);
+			if (ret == -ENOMEM)
+				printk(KERN_ERR TTM_PFX
+					"Out of aperture space or "
+					"DRM memory quota.\n");
+			return ret;
+		}
+	}
+
+	/*
+	 * We might need to add a TTM.
+	 */
+	if (bo->mem.mem_type == TTM_PL_SYSTEM && bo->ttm == NULL) {
+		ret = ttm_bo_add_ttm(bo, true);
+		if (ret)
+			return ret;
+	}
+	/*
+	 * Validation has succeeded, move the access and other
+	 * non-mapping-related flag bits from the proposed flags to
+	 * the active flags
+	 */
+
+	ttm_flag_masked(&bo->mem.placement, bo->proposed_placement,
+			~TTM_PL_MASK_MEMTYPE);
+
+	return 0;
+}
+EXPORT_SYMBOL(ttm_buffer_object_validate_range);
+
 int
 ttm_bo_check_placement(struct ttm_buffer_object *bo,
 		       uint32_t set_flags, uint32_t clr_flags)
@@ -1321,6 +1623,7 @@ int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
 	man->has_type = true;
 	man->use_type = true;
 	man->size = p_size;
+	man->offset = p_offset;
 
 	INIT_LIST_HEAD(&man->lru);
 
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 4911461..3756970 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -308,6 +308,11 @@ extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
 extern int ttm_buffer_object_validate(struct ttm_buffer_object *bo,
 				      uint32_t proposed_placement,
 				      bool interruptible, bool no_wait);
+extern int ttm_buffer_object_validate_range(struct ttm_buffer_object *bo,
+					uint32_t proposed_placement,
+					unsigned long start, unsigned long end,
+					bool interruptible, bool no_wait);
+
 /**
  * ttm_bo_unref
  *
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index e8cd6d2..f00ba12 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -224,6 +224,7 @@ struct ttm_mem_type_manager {
 	unsigned long gpu_offset;
 	unsigned long io_offset;
 	unsigned long io_size;
+	unsigned long offset;
 	void *io_addr;
 	uint64_t size;
 	uint32_t available_caching;
-- 
1.6.5.2