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Commit 7dd737f3 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/dmabuf: Acquire the backing storage outside of struct_mutex 



Use the per-object mm.lock to allocate the backing storage (and hold a
reference to it across the dmabuf access) without resorting to
struct_mutex.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-15-chris@chris-wilson.co.uk
parent 1233e2db

drivers/gpu/drm/i915/i915_gem_dmabuf.c

+30 −39
Original line number Diff line number Diff line
@@ -44,19 +44,15 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme 
	struct scatterlist *src, *dst;

	int ret, i;



	ret = i915_mutex_lock_interruptible(obj->base.dev);

	if (ret)

		goto err;



	ret = i915_gem_object_pin_pages(obj);

	if (ret)

		goto err_unlock;

		goto err;



	/* Copy sg so that we make an independent mapping */

	st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);

	if (st == NULL) {

		ret = -ENOMEM;

		goto err_unpin;

		goto err_unpin_pages;

	}



	ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL);
@@ -76,17 +72,14 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme 
		goto err_free_sg;

	}



	mutex_unlock(&obj->base.dev->struct_mutex);

	return st;



err_free_sg:

	sg_free_table(st);

err_free:

	kfree(st);

err_unpin:

err_unpin_pages:

	i915_gem_object_unpin_pages(obj);

err_unlock:

	mutex_unlock(&obj->base.dev->struct_mutex);

err:

	return ERR_PTR(ret);

}
@@ -101,36 +94,21 @@ static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, 
	sg_free_table(sg);

	kfree(sg);



	mutex_lock(&obj->base.dev->struct_mutex);

	i915_gem_object_unpin_pages(obj);

	mutex_unlock(&obj->base.dev->struct_mutex);

}



static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)

{

	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);

	struct drm_device *dev = obj->base.dev;

	void *addr;

	int ret;



	ret = i915_mutex_lock_interruptible(dev);

	if (ret)

		return ERR_PTR(ret);



	addr = i915_gem_object_pin_map(obj, I915_MAP_WB);

	mutex_unlock(&dev->struct_mutex);



	return addr;

	return i915_gem_object_pin_map(obj, I915_MAP_WB);

}



static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)

{

	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);

	struct drm_device *dev = obj->base.dev;



	mutex_lock(&dev->struct_mutex);

	i915_gem_object_unpin_map(obj);

	mutex_unlock(&dev->struct_mutex);

}



static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
@@ -177,32 +155,45 @@ 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);

	struct drm_device *dev = obj->base.dev;

	int ret;

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

	int err;



	ret = i915_mutex_lock_interruptible(dev);

	if (ret)

		return ret;

	err = i915_gem_object_pin_pages(obj);

	if (err)

		return err;



	err = i915_mutex_lock_interruptible(dev);

	if (err)

		goto out;



	ret = i915_gem_object_set_to_cpu_domain(obj, write);

	err = i915_gem_object_set_to_cpu_domain(obj, write);

	mutex_unlock(&dev->struct_mutex);

	return ret;



out:

	i915_gem_object_unpin_pages(obj);

	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 drm_device *dev = obj->base.dev;

	int ret;

	int err;



	ret = i915_mutex_lock_interruptible(dev);

	if (ret)

		return ret;

	err = i915_gem_object_pin_pages(obj);

	if (err)

		return err;



	ret = i915_gem_object_set_to_gtt_domain(obj, false);

	err = i915_mutex_lock_interruptible(dev);

	if (err)

		goto out;



	err = i915_gem_object_set_to_gtt_domain(obj, false);

	mutex_unlock(&dev->struct_mutex);



	return ret;

out:

	i915_gem_object_unpin_pages(obj);

	return err;

}



static const struct dma_buf_ops i915_dmabuf_ops =  {