drm/nouveau: add reservation to nouveau_gem_ioctl_cpu_prep

Apart from some code inside ttm itself and nouveau_bo_vma_del,
this is the only place where ttm_bo_wait is used without a reservation.
Fix this so we can remove the fence_lock later on.

After the switch to rcu the reservation lock will be
removed again.

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 292a677bfed4ebc649d5ae283a96343773befcfb..0054315eb879759c67535f0536f5a75cd70b104b 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -884,17 +884,31 @@ 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);
-       int ret = -EINVAL;
+       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);
 
-       spin_lock(&nvbo->bo.bdev->fence_lock);
-       ret = ttm_bo_wait(&nvbo->bo, true, true, no_wait);
-       spin_unlock(&nvbo->bo.bdev->fence_lock);
+       ret = ttm_bo_reserve(&nvbo->bo, true, false, false, NULL);
+       if (!ret) {
+               spin_lock(&nvbo->bo.bdev->fence_lock);
+               ret = ttm_bo_wait(&nvbo->bo, true, true, true);
+               if (!no_wait && ret)
+                       fence = nouveau_fence_ref(nvbo->bo.sync_obj);
+               spin_unlock(&nvbo->bo.bdev->fence_lock);
+
+               ttm_bo_unreserve(&nvbo->bo);
+       }
        drm_gem_object_unreference_unlocked(gem);
+
+       if (fence) {
+               ret = nouveau_fence_wait(fence, true, no_wait);
+               nouveau_fence_unref(&fence);
+       }
+
        return ret;
 }