Commit bb6baf76 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Track purged state. 



In order to correctly prevent the invalid reuse of a purged buffer, we
need to track such events and warn the user before something bad
happens.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
parent 9731129c

drivers/gpu/drm/i915/i915_gem.c

+15 −9
Original line number Diff line number Diff line
@@ -1470,6 +1470,7 @@ i915_gem_object_put_pages(struct drm_gem_object *obj) 
	int i;



	BUG_ON(obj_priv->pages_refcount == 0);

	BUG_ON(obj_priv->madv == __I915_MADV_PURGED);



	if (--obj_priv->pages_refcount != 0)

		return;
@@ -1534,11 +1535,14 @@ i915_gem_object_move_to_flushing(struct drm_gem_object *obj) 
static void

i915_gem_object_truncate(struct drm_gem_object *obj)

{

	struct drm_i915_gem_object *obj_priv = obj->driver_private;

	struct inode *inode;



	inode = obj->filp->f_path.dentry->d_inode;

	if (inode->i_op->truncate)

		inode->i_op->truncate (inode);



	obj_priv->madv = __I915_MADV_PURGED;

}



static inline int
@@ -2559,7 +2563,7 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj, unsigned alignment) 
	if (dev_priv->mm.suspended)

		return -EBUSY;



	if (obj_priv->madv == I915_MADV_DONTNEED) {

	if (obj_priv->madv != I915_MADV_WILLNEED) {

		DRM_ERROR("Attempting to bind a purgeable object\n");

		return -EINVAL;

	}
@@ -3928,8 +3932,8 @@ i915_gem_pin_ioctl(struct drm_device *dev, void *data, 
	}

	obj_priv = obj->driver_private;



	if (obj_priv->madv == I915_MADV_DONTNEED) {

		DRM_ERROR("Attempting to pin a I915_MADV_DONTNEED buffer\n");

	if (obj_priv->madv != I915_MADV_WILLNEED) {

		DRM_ERROR("Attempting to pin a purgeable buffer\n");

		drm_gem_object_unreference(obj);

		mutex_unlock(&dev->struct_mutex);

		return -EINVAL;
@@ -4081,14 +4085,16 @@ i915_gem_madvise_ioctl(struct drm_device *dev, void *data, 
		return -EINVAL;

	}



	if (obj_priv->madv != __I915_MADV_PURGED)

		obj_priv->madv = args->madv;

	args->retained = obj_priv->gtt_space != NULL;



	/* if the object is no longer bound, discard its backing storage */

	if (i915_gem_object_is_purgeable(obj_priv) &&

	    obj_priv->gtt_space == NULL)

		i915_gem_object_truncate(obj);



	args->retained = obj_priv->madv != __I915_MADV_PURGED;



	drm_gem_object_unreference(obj);

	mutex_unlock(&dev->struct_mutex);

include/drm/i915_drm.h

+1 −0
Original line number Diff line number Diff line
@@ -671,6 +671,7 @@ struct drm_i915_get_pipe_from_crtc_id { 


#define I915_MADV_WILLNEED 0

#define I915_MADV_DONTNEED 1

#define __I915_MADV_PURGED 2 /* internal state */



struct drm_i915_gem_madvise {

	/** Handle of the buffer to change the backing store advice */