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, 7 insertions, 5 deletions

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 3a03aa64a7a4..041a5ac7eeba 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -115,8 +115,10 @@ static void i915_fence_release(struct dma_fence *fence)
 		   rq->guc_prio != GUC_PRIO_FINI);
 
 	i915_request_free_capture_list(fetch_and_zero(&rq->capture_list));
-	if (i915_vma_snapshot_present(&rq->batch_snapshot))
-		i915_vma_snapshot_put_onstack(&rq->batch_snapshot);
+	if (rq->batch_res) {
+		i915_vma_resource_put(rq->batch_res);
+		rq->batch_res = NULL;
+	}
 
 	/*
 	 * The request is put onto a RCU freelist (i.e. the address
@@ -307,7 +309,7 @@ void i915_request_free_capture_list(struct i915_capture_list *capture)
 	while (capture) {
 		struct i915_capture_list *next = capture->next;
 
-		i915_vma_snapshot_put(capture->vma_snapshot);
+		i915_vma_resource_put(capture->vma_res);
 		kfree(capture);
 		capture = next;
 	}
@@ -853,7 +855,7 @@ static void __i915_request_ctor(void *arg)
 	i915_sw_fence_init(&rq->semaphore, semaphore_notify);
 
 	clear_capture_list(rq);
-	rq->batch_snapshot.present = false;
+	rq->batch_res = NULL;
 
 	init_llist_head(&rq->execute_cb);
 }
@@ -959,7 +961,7 @@ __i915_request_create(struct intel_context *ce, gfp_t gfp)
 	__rq_init_watchdog(rq);
 	assert_capture_list_is_null(rq);
 	GEM_BUG_ON(!llist_empty(&rq->execute_cb));
-	GEM_BUG_ON(i915_vma_snapshot_present(&rq->batch_snapshot));
+	GEM_BUG_ON(rq->batch_res);
 
 	/*
 	 * Reserve space in the ring buffer for all the commands required to