Commit a594525c authored by Maarten Lankhorst's avatar Maarten Lankhorst
Browse files

drm/i915: Allow dead vm to unbind vma's without lock. 



i915_gem_vm_close may take the lock, and we currently have no better way
of handling this. At least for now, allow a path in which holding vm->mutex
is sufficient. This is the case, because the object destroy path will
forcefully take vm->mutex now.

Signed-off-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220128085739.1464568-1-maarten.lankhorst@linux.intel.com


Reviewed-by: default avatarThomas Hellstrom <thomas.hellstrom@linux.intel.com>
parent 7a05c5a0

drivers/gpu/drm/i915/i915_vma.c

+13 −2
Original line number Diff line number Diff line
@@ -39,6 +39,17 @@ 
#include "i915_vma.h"

#include "i915_vma_resource.h"



static inline void assert_vma_held_evict(const struct i915_vma *vma)

{

	/*

	 * We may be forced to unbind when the vm is dead, to clean it up.

	 * This is the only exception to the requirement of the object lock

	 * being held.

	 */

	if (atomic_read(&vma->vm->open))

		assert_object_held_shared(vma->obj);

}



static struct kmem_cache *slab_vmas;



static struct i915_vma *i915_vma_alloc(void)
@@ -1721,7 +1732,7 @@ struct dma_fence *__i915_vma_evict(struct i915_vma *vma, bool async) 
	struct dma_fence *unbind_fence;



	GEM_BUG_ON(i915_vma_is_pinned(vma));

	assert_object_held_shared(vma->obj);

	assert_vma_held_evict(vma);



	if (i915_vma_is_map_and_fenceable(vma)) {

		/* Force a pagefault for domain tracking on next user access */
@@ -1788,7 +1799,7 @@ int __i915_vma_unbind(struct i915_vma *vma) 
	int ret;



	lockdep_assert_held(&vma->vm->mutex);

	assert_object_held_shared(vma->obj);

	assert_vma_held_evict(vma);



	if (!drm_mm_node_allocated(&vma->node))

		return 0;