svn commit: r254862 - head/sys/dev/drm2/ttm

[Jean-Sebastien Pedron]

Author: dumbbell
Date: Sun Aug 25 14:41:22 2013
New Revision: 254862
URL: http://svnweb.freebsd.org/changeset/base/254862

Log:
  drm/ttm: Import Linux commit 7a1863084c9d90ce4b67d645bf9b0f1612e68f62
  
  Author: Maarten Lankhorst <maarten.lankhorst at canonical.com>
  Date:   Tue Jan 15 14:56:48 2013 +0100
  
      drm/ttm: cleanup ttm_eu_reserve_buffers handling
  
      With the lru lock no longer required for protecting reservations we
      can just do a ttm_bo_reserve_nolru on -EBUSY, and handle all errors
      in a single path.
  
      Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com>
      Reviewed-by: Jerome Glisse <jglisse at redhat.com>

Modified:
  head/sys/dev/drm2/ttm/ttm_bo.c
  head/sys/dev/drm2/ttm/ttm_execbuf_util.c

Modified: head/sys/dev/drm2/ttm/ttm_bo.c
==============================================================================
--- head/sys/dev/drm2/ttm/ttm_bo.c	Sun Aug 25 14:39:51 2013	(r254861)
+++ head/sys/dev/drm2/ttm/ttm_bo.c	Sun Aug 25 14:41:22 2013	(r254862)
@@ -659,10 +659,8 @@ static int ttm_bo_delayed_delete(struct 
 
 		ret = ttm_bo_reserve_nolru(entry, false, true, false, 0);
 		if (remove_all && ret) {
-			mtx_unlock(&glob->lru_lock);
 			ret = ttm_bo_reserve_nolru(entry, false, false,
 						   false, 0);
-			mtx_lock(&glob->lru_lock);
 		}
 
 		if (!ret)

Modified: head/sys/dev/drm2/ttm/ttm_execbuf_util.c
==============================================================================
--- head/sys/dev/drm2/ttm/ttm_execbuf_util.c	Sun Aug 25 14:39:51 2013	(r254861)
+++ head/sys/dev/drm2/ttm/ttm_execbuf_util.c	Sun Aug 25 14:41:22 2013	(r254862)
@@ -83,19 +83,6 @@ static void ttm_eu_list_ref_sub(struct l
 	}
 }
 
-static int ttm_eu_wait_unreserved_locked(struct list_head *list,
-					 struct ttm_buffer_object *bo)
-{
-	int ret;
-
-	ttm_eu_del_from_lru_locked(list);
-	ret = ttm_bo_wait_unreserved_locked(bo, true);
-	if (unlikely(ret != 0))
-		ttm_eu_backoff_reservation_locked(list);
-	return ret;
-}
-
-
 void ttm_eu_backoff_reservation(struct list_head *list)
 {
 	struct ttm_validate_buffer *entry;
@@ -149,19 +136,21 @@ retry_locked:
 	list_for_each_entry(entry, list, head) {
 		struct ttm_buffer_object *bo = entry->bo;
 
-retry_this_bo:
 		ret = ttm_bo_reserve_nolru(bo, true, true, true, val_seq);
 		switch (ret) {
 		case 0:
 			break;
 		case -EBUSY:
-			ret = ttm_eu_wait_unreserved_locked(list, bo);
-			if (unlikely(ret != 0)) {
-				mtx_unlock(&glob->lru_lock);
-				ttm_eu_list_ref_sub(list);
-				return ret;
-			}
-			goto retry_this_bo;
+			ttm_eu_del_from_lru_locked(list);
+			ret = ttm_bo_reserve_nolru(bo, true, false,
+						   true, val_seq);
+			if (!ret)
+				break;
+
+			if (unlikely(ret != -EAGAIN))
+				goto err;
+
+			/* fallthrough */
 		case -EAGAIN:
 			ttm_eu_backoff_reservation_locked(list);
 			ttm_eu_list_ref_sub(list);
@@ -172,18 +161,13 @@ retry_this_bo:
 			}
 			goto retry_locked;
 		default:
-			ttm_eu_backoff_reservation_locked(list);
-			mtx_unlock(&glob->lru_lock);
-			ttm_eu_list_ref_sub(list);
-			return ret;
+			goto err;
 		}
 
 		entry->reserved = true;
 		if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
-			ttm_eu_backoff_reservation_locked(list);
-			mtx_unlock(&glob->lru_lock);
-			ttm_eu_list_ref_sub(list);
-			return -EBUSY;
+			ret = -EBUSY;
+			goto err;
 		}
 	}
 
@@ -192,6 +176,12 @@ retry_this_bo:
 	ttm_eu_list_ref_sub(list);
 
 	return 0;
+
+err:
+	ttm_eu_backoff_reservation_locked(list);
+	mtx_unlock(&glob->lru_lock);
+	ttm_eu_list_ref_sub(list);
+	return ret;
 }
 
 void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)