Move macros from virtio_ring.c to virtio_ring.h so that
they can be used outside the file.
Signed-off-by: Sjur Brændeland <sjur.brandeland@xxxxxxxxxxxxxx>
---
drivers/virtio/virtio_ring.c | 21 ---------------------
include/linux/virtio_ring.h | 20 ++++++++++++++++++++
2 files changed, 20 insertions(+), 21 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 6aa76b4..ead47d7 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -24,27 +24,6 @@
#include <linux/module.h>
#include <linux/hrtimer.h>
-/* virtio guest is communicating with a virtual "device" that actually runs on
- * a host processor. Memory barriers are used to control SMP effects. */
-#ifdef CONFIG_SMP
-/* Where possible, use SMP barriers which are more lightweight than mandatory
- * barriers, because mandatory barriers control MMIO effects on accesses
- * through relaxed memory I/O windows (which virtio-pci does not use). */
-#define virtio_mb(vq) \
- do { if ((vq)->vq.weak_barriers) smp_mb(); else mb(); } while (0)
-#define virtio_rmb(vq) \
- do { if ((vq)->vq.weak_barriers) smp_rmb(); else rmb(); } while (0)
-#define virtio_wmb(vq) \
- do { if ((vq)->vq.weak_barriers) smp_wmb(); else wmb(); } while (0)
-#else
-/* We must force memory ordering even if guest is UP since host could be
- * running on another CPU, but SMP barriers are defined to barrier() in that
- * configuration. So fall back to mandatory barriers instead. */
-#define virtio_mb(vq) mb()
-#define virtio_rmb(vq) rmb()
-#define virtio_wmb(vq) wmb()
-#endif
-
#ifdef DEBUG
/* For development, we want to crash whenever the ring is screwed. */
#define BAD_RING(_vq, fmt, args...) \
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index 6c9b871..1a4023b 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -42,4 +42,24 @@ int vring_avail_desc_user(struct vring_host *vh);
struct vring_used_elem *vring_add_used_user(struct vring_host *vh,
unsigned int head, int len);
+/* virtio guest is communicating with a virtual "device" that actually runs on
+ * a host processor. Memory barriers are used to control SMP effects. */
+#ifdef CONFIG_SMP
+/* Where possible, use SMP barriers which are more lightweight than mandatory
+ * barriers, because mandatory barriers control MMIO effects on accesses
+ * through relaxed memory I/O windows (which virtio-pci does not use). */
+#define virtio_mb(vq) \
+ do { if ((vq)->vq.weak_barriers) smp_mb(); else mb(); } while (0)
+#define virtio_rmb(vq) \
+ do { if ((vq)->vq.weak_barriers) smp_rmb(); else rmb(); } while (0)
+#define virtio_wmb(vq) \
+ do { if ((vq)->vq.weak_barriers) smp_wmb(); else wmb(); } while (0)
+#else
+/* We must force memory ordering even if guest is UP since host could be
+ * running on another CPU, but SMP barriers are defined to barrier() in that
+ * configuration. So fall back to mandatory barriers instead. */
+#define virtio_mb(vq) mb()
+#define virtio_rmb(vq) rmb()
+#define virtio_wmb(vq) wmb()
+#endif
#endif /* _LINUX_VIRTIO_RING_H */
--
1.7.5.4
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