drm/i915: Use struct vma_resource instead of struct vma_snapshot

There is always a struct vma_resource guaranteed to be alive when we
access a corresponding struct vma_snapshot.

So ditch the latter and instead of allocating vma_snapshots, reference
the already existning vma_resource.

This requires a couple of extra members in struct vma_resource but that's
a small price to pay for the simplification.

v2:
- Fix a missing include and declaration (kernel test robot <lkp@intel.com>)

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220110172219.107131-7-thomas.hellstrom@linux.intel.com

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_vma_resource.c b/drivers/gpu/drm/i915/i915_vma_resource.c
index 3e55a30b2da7..1f41c0c699eb 100644
--- a/drivers/gpu/drm/i915/i915_vma_resource.c
+++ b/drivers/gpu/drm/i915/i915_vma_resource.c
@@ -9,6 +9,7 @@
 #include "i915_sw_fence.h"
 #include "i915_vma_resource.h"
 #include "i915_drv.h"
+#include "intel_memory_region.h"
 
 #include "gt/intel_gtt.h"
 
@@ -117,6 +118,9 @@ static void __i915_vma_resource_unhold(struct i915_vma_resource *vma_res)
 		vma_res_itree_remove(vma_res, &vm->pending_unbind);
 		mutex_unlock(&vm->mutex);
 	}
+
+	if (vma_res->bi.pages_rsgt)
+		i915_refct_sgt_put(vma_res->bi.pages_rsgt);
 }
 
 /**