drm/i915: Be defensive when starting vma activity

Before we acquire the vma for GPU activity, ensure that the underlying
object is not already in the process of being freed.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190820100531.8430-1-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2019-08-20 11:05:31 +01:00
parent 44c22f3f1a
commit 2833ddccbd
2 changed files with 9 additions and 2 deletions

View file

@ -87,8 +87,7 @@ static inline struct i915_vma *active_to_vma(struct i915_active *ref)
static int __i915_vma_active(struct i915_active *ref)
{
i915_vma_get(active_to_vma(ref));
return 0;
return i915_vma_tryget(active_to_vma(ref)) ? 0 : -ENOENT;
}
static void __i915_vma_retire(struct i915_active *ref)

View file

@ -231,6 +231,14 @@ static inline struct i915_vma *i915_vma_get(struct i915_vma *vma)
return vma;
}
static inline struct i915_vma *i915_vma_tryget(struct i915_vma *vma)
{
if (likely(kref_get_unless_zero(&vma->obj->base.refcount)))
return vma;
return NULL;
}
static inline void i915_vma_put(struct i915_vma *vma)
{
i915_gem_object_put(vma->obj);