virtio: more neatening of virtio_ring macros.

[deliverable/linux.git] / drivers / virtio / virtio_ring.c

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 5777196bf6c9cc873ef07dd6e79eb10f1775379b..5c52369ab9bb81115376ec3e8b959908bdbe8d8f 100644 (file)
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -23,15 +23,21 @@
 
 #ifdef DEBUG
 /* For development, we want to crash whenever the ring is screwed. */
-#define BAD_RING(vq, fmt...)                   \
-       do { dev_err(&vq->vq.vdev->dev, fmt); BUG(); } while(0)
-#define START_USE(vq) \
-       do { if ((vq)->in_use) panic("in_use = %i\n", (vq)->in_use); (vq)->in_use = __LINE__; mb(); } while(0)
-#define END_USE(vq) \
-       do { BUG_ON(!(vq)->in_use); (vq)->in_use = 0; mb(); } while(0)
+#define BAD_RING(_vq, fmt...)                  \
+       do { dev_err(&(_vq)->vq.vdev->dev, fmt); BUG(); } while(0)
+/* Caller is supposed to guarantee no reentry. */
+#define START_USE(_vq)                                         \
+       do {                                                    \
+               if ((_vq)->in_use)                              \
+                       panic("in_use = %i\n", (_vq)->in_use);  \
+               (_vq)->in_use = __LINE__;                       \
+               mb();                                           \
+       } while(0)
+#define END_USE(_vq) \
+       do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; mb(); } while(0)
 #else
-#define BAD_RING(vq, fmt...)                   \
-       do { dev_err(&vq->vq.vdev->dev, fmt); (vq)->broken = true; } while(0)
+#define BAD_RING(_vq, fmt...)                  \
+       do { dev_err(&_vq->vq.vdev->dev, fmt); (_vq)->broken = true; } while(0)
 #define START_USE(vq)
 #define END_USE(vq)
 #endif