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>
This commit is contained in:
Michael S. Tsirkin 2012-11-01 09:16:37 +00:00 committed by David S. Miller
parent 149d36f718
commit 70e4cb9aaf
3 changed files with 12 additions and 5 deletions

View File

@ -237,7 +237,8 @@ static void handle_tx(struct vhost_net *net)
} else {
struct ubuf_info *ubuf = &vq->ubuf_info[head];
vq->heads[vq->upend_idx].len = len;
vq->heads[vq->upend_idx].len =
VHOST_DMA_IN_PROGRESS;
ubuf->callback = vhost_zerocopy_callback;
ubuf->ctx = vq->ubufs;
ubuf->desc = vq->upend_idx;

View File

@ -1606,7 +1606,7 @@ void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool status)
struct vhost_virtqueue *vq = ubufs->vq;
vhost_poll_queue(&vq->poll);
/* set len = 1 to mark this desc buffers done DMA */
/* set len to mark this desc buffers done DMA */
vq->heads[ubuf->desc].len = VHOST_DMA_DONE_LEN;
kref_put(&ubufs->kref, vhost_zerocopy_done_signal);
}

View File

@ -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;