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Commit 70001cd2 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Remove struct_mutex for destroying framebuffers 



We do not need to hold struct_mutex for destroying drm_i915_gem_objects
any longer, and with a little care taken over tracking
obj->framebuffer_references, we can relinquish BKL locking around the
destroy of intel_framebuffer.

v2: Use atomic check for WARN_ON framebuffer miscounting

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170216094621.3426-1-chris@chris-wilson.co.uk


Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
parent 581ab1fe

drivers/gpu/drm/i915/i915_gem_object.h

+1 −1
Original line number Diff line number Diff line
@@ -165,7 +165,7 @@ struct drm_i915_gem_object { 
	struct reservation_object *resv;



	/** References from framebuffers, locks out tiling changes. */

	unsigned long framebuffer_references;

	atomic_t framebuffer_references;



	/** Record of address bit 17 of each page at last unbind. */

	unsigned long *bit_17;

drivers/gpu/drm/i915/i915_gem_shrinker.c

+1 −1
Original line number Diff line number Diff line
@@ -207,7 +207,7 @@ i915_gem_shrink(struct drm_i915_private *dev_priv, 


			if (!(flags & I915_SHRINK_ACTIVE) &&

			    (i915_gem_object_is_active(obj) ||

			     obj->framebuffer_references))

			     atomic_read(&obj->framebuffer_references)))

				continue;



			if (!can_release_pages(obj))

drivers/gpu/drm/i915/i915_gem_tiling.c

+1 −1
Original line number Diff line number Diff line
@@ -238,7 +238,7 @@ i915_gem_object_set_tiling(struct drm_i915_gem_object *obj, 
	if ((tiling | stride) == obj->tiling_and_stride)

		return 0;



	if (obj->framebuffer_references)

	if (atomic_read(&obj->framebuffer_references))

		return -EBUSY;



	/* We need to rebind the object if its current allocation

drivers/gpu/drm/i915/intel_display.c

+4 −5
Original line number Diff line number Diff line
@@ -14265,14 +14265,13 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv) 


static void intel_user_framebuffer_destroy(struct drm_framebuffer *fb)

{

	struct drm_device *dev = fb->dev;

	struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);



	drm_framebuffer_cleanup(fb);

	mutex_lock(&dev->struct_mutex);

	WARN_ON(!intel_fb->obj->framebuffer_references--);



	WARN_ON(atomic_dec_return(&intel_fb->obj->framebuffer_references) < 0);

	i915_gem_object_put(intel_fb->obj);

	mutex_unlock(&dev->struct_mutex);



	kfree(intel_fb);

}
@@ -14509,7 +14508,7 @@ static int intel_framebuffer_init(struct drm_device *dev, 
		return ret;

	}



	intel_fb->obj->framebuffer_references++;

	atomic_inc(&intel_fb->obj->framebuffer_references);



	return 0;

}