drm/vmwgfx: Ditch the vmw_dummy_query_bo_prepare function

Combine it with vmw_dummy_query_bo_create, and also make sure
we use tryreserve when reserving the bo to avoid any lockdep warnings
We are sure the tryreserve will always succeed since we are
the only users at that point.
In addition, allow the vmw_bo_pin function to pin/unpin system memory.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>

drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c

@@ -290,8 +290,7 @@ void vmw_bo_get_guest_ptr(const struct ttm_buffer_object *bo,
 /**
  * vmw_bo_pin - Pin or unpin a buffer object without moving it.
  *
- * @bo: The buffer object. Must be reserved, and present either in VRAM
- * or GMR memory.
+ * @bo: The buffer object. Must be reserved.
  * @pin: Whether to pin or unpin.
  *
  */
@@ -303,12 +302,9 @@ void vmw_bo_pin(struct ttm_buffer_object *bo, bool pin)
 	int ret;
 
 	lockdep_assert_held(&bo->resv->lock.base);
-	BUG_ON(old_mem_type != TTM_PL_VRAM &&
-	       old_mem_type != VMW_PL_GMR &&
-	       old_mem_type != VMW_PL_MOB);
 
 	pl_flags = TTM_PL_FLAG_VRAM | VMW_PL_FLAG_GMR | VMW_PL_FLAG_MOB
-		| TTM_PL_FLAG_CACHED;
+		| TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED;
 	if (pin)
 		pl_flags |= TTM_PL_FLAG_NO_EVICT;
 

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c

@@ -281,36 +281,44 @@ static void vmw_print_capabilities(uint32_t capabilities)
 		DRM_INFO("  Guest Backed Resources.\n");
 }
 
-
 /**
- * vmw_execbuf_prepare_dummy_query - Initialize a query result structure at
- * the start of a buffer object.
+ * vmw_dummy_query_bo_create - create a bo to hold a dummy query result
  *
- * @dev_priv: The device private structure.
+ * @dev_priv: A device private structure.
  *
- * This function will idle the buffer using an uninterruptible wait, then
- * map the first page and initialize a pending occlusion query result structure,
- * Finally it will unmap the buffer.
+ * This function creates a small buffer object that holds the query
+ * result for dummy queries emitted as query barriers.
+ * The function will then map the first page and initialize a pending
+ * occlusion query result structure, Finally it will unmap the buffer.
+ * No interruptible waits are done within this function.
  *
- * TODO: Since we're only mapping a single page, we should optimize the map
- * to use kmap_atomic / iomap_atomic.
+ * Returns an error if bo creation or initialization fails.
  */
-static void vmw_dummy_query_bo_prepare(struct vmw_private *dev_priv)
+static int vmw_dummy_query_bo_create(struct vmw_private *dev_priv)
 {
+	int ret;
+	struct ttm_buffer_object *bo;
 	struct ttm_bo_kmap_obj map;
 	volatile SVGA3dQueryResult *result;
 	bool dummy;
-	int ret;
-	struct ttm_bo_device *bdev = &dev_priv->bdev;
-	struct ttm_buffer_object *bo = dev_priv->dummy_query_bo;
 
-	ttm_bo_reserve(bo, false, false, false, 0);
-	spin_lock(&bdev->fence_lock);
-	ret = ttm_bo_wait(bo, false, false, false);
-	spin_unlock(&bdev->fence_lock);
+	/*
+	 * Create the bo as pinned, so that a tryreserve will
+	 * immediately succeed. This is because we're the only
+	 * user of the bo currently.
+	 */
+	ret = ttm_bo_create(&dev_priv->bdev,
+			    PAGE_SIZE,
+			    ttm_bo_type_device,
+			    &vmw_sys_ne_placement,
+			    0, false, NULL,
+			    &bo);
+
 	if (unlikely(ret != 0))
-		(void) vmw_fallback_wait(dev_priv, false, true, 0, false,
-					 10*HZ);
+		return ret;
+
+	ret = ttm_bo_reserve(bo, false, true, false, 0);
+	BUG_ON(ret != 0);
 
 	ret = ttm_bo_kmap(bo, 0, 1, &map);
 	if (likely(ret == 0)) {
@@ -319,34 +327,19 @@ static void vmw_dummy_query_bo_prepare(struct vmw_private *dev_priv)
 		result->state = SVGA3D_QUERYSTATE_PENDING;
 		result->result32 = 0xff;
 		ttm_bo_kunmap(&map);
-	} else
-		DRM_ERROR("Dummy query buffer map failed.\n");
+	}
+	vmw_bo_pin(bo, false);
 	ttm_bo_unreserve(bo);
-}
 
+	if (unlikely(ret != 0)) {
+		DRM_ERROR("Dummy query buffer map failed.\n");
+		ttm_bo_unref(&bo);
+	} else
+		dev_priv->dummy_query_bo = bo;
 
-/**
- * vmw_dummy_query_bo_create - create a bo to hold a dummy query result
- *
- * @dev_priv: A device private structure.
- *
- * This function creates a small buffer object that holds the query
- * result for dummy queries emitted as query barriers.
- * No interruptible waits are done within this function.
- *
- * Returns an error if bo creation fails.
- */
-static int vmw_dummy_query_bo_create(struct vmw_private *dev_priv)
-{
-	return ttm_bo_create(&dev_priv->bdev,
-			     PAGE_SIZE,
-			     ttm_bo_type_device,
-			     &vmw_vram_sys_placement,
-			     0, false, NULL,
-			     &dev_priv->dummy_query_bo);
+	return ret;
 }
 
-
 static int vmw_request_device(struct vmw_private *dev_priv)
 {
 	int ret;
@@ -368,7 +361,6 @@ static int vmw_request_device(struct vmw_private *dev_priv)
 	ret = vmw_dummy_query_bo_create(dev_priv);
 	if (unlikely(ret != 0))
 		goto out_no_query_bo;
-	vmw_dummy_query_bo_prepare(dev_priv);
 
 	return 0;