drm/msm: Count how many times iova memory is pinned

Add a reference count to track how many times a particular
chunk of iova memory is pinned (mapped) in the iomu and
add msm_gem_unpin_iova to give up references.

It is important to note that msm_gem_unpin_iova replaces
msm_gem_put_iova because the new implicit behavior
that an assigned iova in a given vma is now valid for the
life of the buffer and what we are really focusing on is
the use of that iova.

For now the unmappings are lazy; once the reference counts
go to zero they *COULD* be unmapped dynamically but that
will require an outside force such as a shrinker or
mm_notifiers.  For now, we're just focusing on getting
the counting right and setting ourselves up to be ready
for the future.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index fcfff333ed96..86bb1ed8ddbb 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -689,7 +689,7 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
 		struct msm_gem_object *msm_obj = submit->bos[i].obj;
 		/* move to inactive: */
 		msm_gem_move_to_inactive(&msm_obj->base);
-		msm_gem_put_iova(&msm_obj->base, gpu->aspace);
+		msm_gem_unpin_iova(&msm_obj->base, gpu->aspace);
 		drm_gem_object_put(&msm_obj->base);
 	}