Commit e944e3cf authored by Maarten Lankhorst's avatar Maarten Lankhorst Committed by Daniel Vetter
Browse files

drm/i915: Add ww locking to dma-buf ops, v2. 



vmap is using pin_pages, but needs to use ww locking,
add pin_pages_unlocked to correctly lock the mapping.

Also add ww locking to begin/end cpu access.

Changes since v1:
- Fix i915_gem_map_dma_buf by using pin_pages_unlocked().

Signed-off-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-38-maarten.lankhorst@linux.intel.com
parent c858ffa1

drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c

+34 −28
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme 
	struct scatterlist *src, *dst;

	int ret, i;



	ret = i915_gem_object_pin_pages(obj);

	ret = i915_gem_object_pin_pages_unlocked(obj);

	if (ret)

		goto err;
@@ -82,7 +82,7 @@ static int i915_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map 
	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);

	void *vaddr;



	vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);

	vaddr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);

	if (IS_ERR(vaddr))

		return PTR_ERR(vaddr);
@@ -123,42 +123,48 @@ static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_dire 
{

	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);

	bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);

	struct i915_gem_ww_ctx ww;

	int err;



	i915_gem_ww_ctx_init(&ww, true);

retry:

	err = i915_gem_object_lock(obj, &ww);

	if (!err)

		err = i915_gem_object_pin_pages(obj);

	if (err)

		return err;



	err = i915_gem_object_lock_interruptible(obj, NULL);

	if (err)

		goto out;



	if (!err) {

		err = i915_gem_object_set_to_cpu_domain(obj, write);

	i915_gem_object_unlock(obj);



out:

		i915_gem_object_unpin_pages(obj);

	}

	if (err == -EDEADLK) {

		err = i915_gem_ww_ctx_backoff(&ww);

		if (!err)

			goto retry;

	}

	i915_gem_ww_ctx_fini(&ww);

	return err;

}



static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)

{

	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);

	struct i915_gem_ww_ctx ww;

	int err;



	i915_gem_ww_ctx_init(&ww, true);

retry:

	err = i915_gem_object_lock(obj, &ww);

	if (!err)

		err = i915_gem_object_pin_pages(obj);

	if (err)

		return err;



	err = i915_gem_object_lock_interruptible(obj, NULL);

	if (err)

		goto out;



	if (!err) {

		err = i915_gem_object_set_to_gtt_domain(obj, false);

	i915_gem_object_unlock(obj);



out:

		i915_gem_object_unpin_pages(obj);

	}

	if (err == -EDEADLK) {

		err = i915_gem_ww_ctx_backoff(&ww);

		if (!err)

			goto retry;

	}

	i915_gem_ww_ctx_fini(&ww);

	return err;

}