TLB cache invalidation can happen on two different situations: 1. synchronously, at __vma_put_pages(); 2. asynchronously. On the first case, TLB cache invalidation happens inside __vma_put_pages(). So, no need to do it later on. However, on the second case, the pages will keep in memory until __i915_vma_evict() is called. So, we need to store the TLB data at struct i915_vma_resource, in order to do a TLB cache invalidation before allowing userspace to re-use the same memory. So, i915_vma_resource_unbind() has gained a new parameter in order to store the TLB data at the second case. Document it. Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> --- See [PATCH 00/21] at: https://lore.kernel.org/all/cover.1657703926.git.mchehab@xxxxxxxxxx/ drivers/gpu/drm/i915/i915_vma_resource.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_vma_resource.c b/drivers/gpu/drm/i915/i915_vma_resource.c index 5a67995ea5fe..4fe09ea0a825 100644 --- a/drivers/gpu/drm/i915/i915_vma_resource.c +++ b/drivers/gpu/drm/i915/i915_vma_resource.c @@ -216,6 +216,10 @@ i915_vma_resource_fence_notify(struct i915_sw_fence *fence, /** * i915_vma_resource_unbind - Unbind a vma resource * @vma_res: The vma resource to unbind. + * @tlb: pointer to vma->obj->mm.tlb associated with the resource + * to be stored at vma_res->tlb. When not-NULL, it will be used + * to do TLB cache invalidation before freeing a VMA resource. + * used only for async unbind. * * At this point this function does little more than publish a fence that * signals immediately unless signaling is held back. -- 2.36.1
