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Diffstat (limited to 'include')
-rw-r--r--include/linux/virtio_config.h25
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index b341dd62aa4d..25be018810a7 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -57,6 +57,11 @@ struct virtio_shm_region {
* include a NULL entry for vqs unused by driver
* Returns 0 on success or error status
* @del_vqs: free virtqueues found by find_vqs().
+ * @synchronize_cbs: synchronize with the virtqueue callbacks (optional)
+ * The function guarantees that all memory operations on the
+ * queue before it are visible to the vring_interrupt() that is
+ * called after it.
+ * vdev: the virtio_device
* @get_features: get the array of feature bits for this device.
* vdev: the virtio_device
* Returns the first 64 feature bits (all we currently need).
@@ -89,6 +94,7 @@ struct virtio_config_ops {
const char * const names[], const bool *ctx,
struct irq_affinity *desc);
void (*del_vqs)(struct virtio_device *);
+ void (*synchronize_cbs)(struct virtio_device *);
u64 (*get_features)(struct virtio_device *vdev);
int (*finalize_features)(struct virtio_device *vdev);
const char *(*bus_name)(struct virtio_device *vdev);
@@ -218,6 +224,25 @@ int virtio_find_vqs_ctx(struct virtio_device *vdev, unsigned nvqs,
}
/**
+ * virtio_synchronize_cbs - synchronize with virtqueue callbacks
+ * @vdev: the device
+ */
+static inline
+void virtio_synchronize_cbs(struct virtio_device *dev)
+{
+ if (dev->config->synchronize_cbs) {
+ dev->config->synchronize_cbs(dev);
+ } else {
+ /*
+ * A best effort fallback to synchronize with
+ * interrupts, preemption and softirq disabled
+ * regions. See comment above synchronize_rcu().
+ */
+ synchronize_rcu();
+ }
+}
+
+/**
* virtio_device_ready - enable vq use in probe function
* @vdev: the device
*