drm/nouveau: use rcu in nouveau_gem_ioctl_cpu_prep

With the conversion to the reservation api this should be safe.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index a28b510..4120289 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -861,33 +861,29 @@ nouveau_gem_ioctl_cpu_prep(struct drm_device *dev, void *data,
        struct drm_gem_object *gem;
        struct nouveau_bo *nvbo;
        bool no_wait = !!(req->flags & NOUVEAU_GEM_CPU_PREP_NOWAIT);
+       bool write = !!(req->flags & NOUVEAU_GEM_CPU_PREP_WRITE);
        int ret;
-       struct nouveau_fence *fence = NULL;
 
        gem = drm_gem_object_lookup(dev, file_priv, req->handle);
        if (!gem)
                return -ENOENT;
        nvbo = nouveau_gem_object(gem);
 
-       ret = ttm_bo_reserve(&nvbo->bo, true, false, false, NULL);
-       if (!ret) {
-               ret = ttm_bo_wait(&nvbo->bo, true, true, true);
-               if (!no_wait && ret) {
-                       struct fence *excl;
-
-                       excl = reservation_object_get_excl(nvbo->bo.resv);
-                       fence = nouveau_fence_ref((struct nouveau_fence *)excl);
-               }
+       if (no_wait)
+               ret = reservation_object_test_signaled_rcu(nvbo->bo.resv, write) ? 0 : -EBUSY;
+       else {
+               long lret;
 
-               ttm_bo_unreserve(&nvbo->bo);
+               lret = reservation_object_wait_timeout_rcu(nvbo->bo.resv, write, true, 30 * HZ);
+               if (!lret)
+                       ret = -EBUSY;
+               else if (lret > 0)
+                       ret = 0;
+               else
+                       ret = lret;
        }
        drm_gem_object_unreference_unlocked(gem);
 
-       if (fence) {
-               ret = nouveau_fence_wait(fence, true, no_wait);
-               nouveau_fence_unref(&fence);
-       }
-
        return ret;
 }