I915_VMA_PIN_MASK
atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
if (unlikely(!((bound + 1) & I915_VMA_PIN_MASK))) {
atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
GEM_BUG_ON(((bound + 1) & I915_VMA_PIN_MASK) == 0);
return atomic_read(&vma->flags) & I915_VMA_PIN_MASK;