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authorMichael S. Tsirkin <mst@redhat.com>2012-11-01 09:16:37 +0000
committerDavid S. Miller <davem@davemloft.net>2012-11-02 21:29:57 -0400
commit70e4cb9aafb3caa9e5eb25614a5bc40b0ffa9ffd (patch)
treef3b88279253e04599ac949e393ee0820ceaa5f57 /drivers/vhost/vhost.h
parent149d36f7187cbd10beff88e4e20f93e51a34827e (diff)
vhost-net: cleanup macros for DMA status tracking
Better document macros for DMA tracking. Add an explicit one for DMA in progress instead of relying on user supplying len != 1. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/vhost/vhost.h')
-rw-r--r--drivers/vhost/vhost.h12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 2de4ce2fec40..b6538eef7468 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -13,9 +13,15 @@
#include <linux/virtio_ring.h>
#include <linux/atomic.h>
-/* This is for zerocopy, used buffer len is set to 1 when lower device DMA
- * done */
-#define VHOST_DMA_DONE_LEN 1
+/*
+ * For transmit, used buffer len is unused; we override it to track buffer
+ * status internally; used for zerocopy tx only.
+ */
+/* Lower device DMA done */
+#define VHOST_DMA_DONE_LEN 2
+/* Lower device DMA in progress */
+#define VHOST_DMA_IN_PROGRESS 1
+/* Buffer unused */
#define VHOST_DMA_CLEAR_LEN 0
struct vhost_device;