nouveau: Rename buffer on map if discardable, busy, and write-only.

diff --git a/src/gallium/winsys/drm/nouveau/common/nouveau_winsys_pipe.c b/src/gallium/winsys/drm/nouveau/common/nouveau_winsys_pipe.c
index 683710e..5b3101f 100644 (file)
--- a/src/gallium/winsys/drm/nouveau/common/nouveau_winsys_pipe.c
+++ b/src/gallium/winsys/drm/nouveau/common/nouveau_winsys_pipe.c
@@ -121,6 +121,21 @@ nouveau_pipe_bo_map(struct pipe_winsys *pws, struct pipe_buffer *buf,
        if (flags & PIPE_BUFFER_USAGE_CPU_WRITE)
                map_flags |= NOUVEAU_BO_WR;
 
+       if (flags & PIPE_BUFFER_USAGE_DISCARD &&
+           !(flags & PIPE_BUFFER_USAGE_CPU_READ) &&
+           nouveau_bo_busy(nvbuf->bo, map_flags)) {
+               struct nouveau_pipe_winsys *nvpws = (struct nouveau_pipe_winsys *)pws;
+               struct nouveau_context *nv = nvpws->nv;
+               struct nouveau_device *dev = nv->nv_screen->device;
+               struct nouveau_bo *rename;
+               uint32_t flags = nouveau_flags_from_usage(nv, buf->usage);
+
+               if (!nouveau_bo_new(dev, flags, buf->alignment, buf->size, &rename)) {
+                       nouveau_bo_del(&nvbuf->bo);
+                       nvbuf->bo = rename;
+               }
+       }
+
        if (nouveau_bo_map(nvbuf->bo, map_flags))
                return NULL;
        return nvbuf->bo->map;