[PATCH 61/62] lock-vma

[Chris Wilson]

---
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 68 +++++++++++--------
 1 file changed, 41 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index be00f077d6fc..e1bf1f30dca7 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -358,6 +358,42 @@ static void eb_vma_array_put(struct eb_vma_array *arr)
 	kref_put(&arr->kref, eb_vma_array_destroy);
 }
 
+static int
+eb_lock_vma(struct i915_execbuffer *eb, struct ww_acquire_ctx *acquire)
+{
+	struct eb_vma *ev;
+	int err = 0;
+
+	list_for_each_entry(ev, &eb->lock, lock_link) {
+		struct i915_vma *vma = ev->vma;
+
+		err = ww_mutex_lock_interruptible(&vma->resv->lock, acquire);
+		if (err == -EDEADLK) {
+			struct eb_vma *unlock = ev, *en;
+
+			list_for_each_entry_safe_continue_reverse(unlock, en,
+								  &eb->lock,
+								  lock_link) {
+				ww_mutex_unlock(&unlock->vma->resv->lock);
+				list_move_tail(&unlock->lock_link, &eb->lock);
+			}
+
+			GEM_BUG_ON(!list_is_first(&ev->lock_link, &eb->lock));
+			err = ww_mutex_lock_slow_interruptible(&vma->resv->lock,
+							       acquire);
+		}
+		if (err) {
+			list_for_each_entry_continue_reverse(ev,
+							     &eb->lock,
+							     lock_link)
+				ww_mutex_unlock(&ev->vma->resv->lock);
+			break;
+		}
+	}
+
+	return err;
+}
+
 static int eb_create(struct i915_execbuffer *eb)
 {
 	/* Allocate an extra slot for use by the command parser + sentinel */
@@ -2400,34 +2436,10 @@ static int eb_move_to_gpu(struct i915_execbuffer *eb)
 
 	ww_acquire_init(&acquire, &reservation_ww_class);
 
-	list_for_each_entry(ev, &eb->lock, lock_link) {
-		struct i915_vma *vma = ev->vma;
-
-		err = ww_mutex_lock_interruptible(&vma->resv->lock, &acquire);
-		if (err == -EDEADLK) {
-			struct eb_vma *unlock = ev, *en;
-
-			list_for_each_entry_safe_continue_reverse(unlock, en,
-								  &eb->lock,
-								  lock_link) {
-				ww_mutex_unlock(&unlock->vma->resv->lock);
-				list_move_tail(&unlock->lock_link, &eb->lock);
-			}
-
-			GEM_BUG_ON(!list_is_first(&ev->lock_link, &eb->lock));
-			err = ww_mutex_lock_slow_interruptible(&vma->resv->lock,
-							       &acquire);
-		}
-		if (err) {
-			list_for_each_entry_continue_reverse(ev,
-							     &eb->lock,
-							     lock_link)
-				ww_mutex_unlock(&ev->vma->resv->lock);
+	err = eb_lock_vma(eb, &acquire);
+	if (err)
+		goto err_fini;
 
-			ww_acquire_fini(&acquire);
-			goto err_skip;
-		}
-	}
 	ww_acquire_done(&acquire);
 
 	list_for_each_entry(ev, &eb->lock, lock_link) {
@@ -2486,6 +2498,8 @@ static int eb_move_to_gpu(struct i915_execbuffer *eb)
 	intel_gt_chipset_flush(eb->engine->gt);
 	return 0;
 
+err_fini:
+	ww_acquire_fini(&acquire);
 err_skip:
 	i915_request_set_error_once(eb->request, err);
 	return err;
-- 
2.20.1