diff options
| author | David Riley <davidriley@chromium.org> | 2019-06-10 14:18:10 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-08-04 09:34:56 +0200 |
| commit | 25d2b1b5f27b3b559ade1a4024e746bb41106c80 (patch) | |
| tree | 5e576ad8432dc6d8f575e0334499571aac64c0fd /drivers/gpu | |
| parent | e14829d6f80f635dacb84615b67666dfd6457e26 (diff) | |
drm/virtio: Add memory barriers for capset cache.
[ Upstream commit 9ff3a5c88e1f1ab17a31402b96d45abe14aab9d7 ]
After data is copied to the cache entry, atomic_set is used indicate
that the data is the entry is valid without appropriate memory barriers.
Similarly the read side was missing the corresponding memory barriers.
Signed-off-by: David Riley <davidriley@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20190610211810.253227-5-davidriley@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/virtio/virtgpu_ioctl.c | 3 | ||||
| -rw-r--r-- | drivers/gpu/drm/virtio/virtgpu_vq.c | 2 |
2 files changed, 5 insertions, 0 deletions
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index 6296e9f270ca..0b8f8c10f2ed 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -535,6 +535,9 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, ret = wait_event_timeout(vgdev->resp_wq, atomic_read(&cache_ent->is_valid), 5 * HZ); + /* is_valid check must proceed before copy of the cache entry. */ + smp_rmb(); + ptr = cache_ent->caps_cache; copy_exit: diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 52436b3c01bb..a1b3ea1ccb65 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -618,6 +618,8 @@ static void virtio_gpu_cmd_capset_cb(struct virtio_gpu_device *vgdev, cache_ent->id == le32_to_cpu(cmd->capset_id)) { memcpy(cache_ent->caps_cache, resp->capset_data, cache_ent->size); + /* Copy must occur before is_valid is signalled. */ + smp_wmb(); atomic_set(&cache_ent->is_valid, 1); break; } |