Now, if we want to judge the rx work mode, we have to use such codes:
1. merge mode: vi->mergeable_rx_bufs
2. big mode: vi->big_packets && !vi->mergeable_rx_bufs
3. small: !vi->big_packets && !vi->mergeable_rx_bufs
This is inconvenient and abstract, and we also have this use case:
if (vi->mergeable_rx_bufs)
....
else if (vi->big_packets)
....
else
For this case, I think switch-case is the better choice.
So here I introduce vi->mode to record the virtio-net work mode.
That is helpful to judge the work mode and choose the branches.
Signed-off-by: Xuan Zhuo <[email protected]>
---
drivers/net/virtio_net.c | 61 +++++++++++++++++++++++++++++++---------
1 file changed, 47 insertions(+), 14 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 59a99bbaf852..14809b614d62 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -385,6 +385,12 @@ struct control_buf {
virtio_net_ctrl_ack status;
};
+enum virtnet_mode {
+ VIRTNET_MODE_SMALL,
+ VIRTNET_MODE_MERGE,
+ VIRTNET_MODE_BIG
+};
+
struct virtnet_info {
struct virtio_device *vdev;
struct virtqueue *cvq;
@@ -414,6 +420,8 @@ struct virtnet_info {
/* Host will merge rx buffers for big packets (shake it! shake it!) */
bool mergeable_rx_bufs;
+ enum virtnet_mode mode;
+
/* Host supports rss and/or hash report */
bool has_rss;
bool has_rss_hash_report;
@@ -643,12 +651,15 @@ static struct page *get_a_page(struct receive_queue *rq,
gfp_t gfp_mask)
static void virtnet_rq_free_buf(struct virtnet_info *vi,
struct receive_queue *rq, void *buf)
{
- if (vi->mergeable_rx_bufs)
+ switch (vi->mode) {
+ case VIRTNET_MODE_SMALL:
+ case VIRTNET_MODE_MERGE:
put_page(virt_to_head_page(buf));
- else if (vi->big_packets)
+ break;
+ case VIRTNET_MODE_BIG:
give_pages(rq, buf);
- else
- put_page(virt_to_head_page(buf));
+ break;
+ }
}
static void enable_delayed_refill(struct virtnet_info *vi)
@@ -1315,7 +1326,8 @@ static void virtnet_receive_xsk_buf(struct virtnet_info
*vi, struct receive_queu
flags = ((struct virtio_net_common_hdr *)(xdp->data -
vi->hdr_len))->hdr.flags;
- if (!vi->mergeable_rx_bufs)
+ /* We only support small and merge mode. */
+ if (vi->mode == VIRTNET_MODE_SMALL)
skb = virtnet_receive_xsk_small(dev, vi, rq, xdp, xdp_xmit,
stats);
else
skb = virtnet_receive_xsk_merge(dev, vi, rq, xdp, xdp_xmit,
stats);
@@ -2389,13 +2401,20 @@ static void receive_buf(struct virtnet_info *vi, struct
receive_queue *rq,
*/
flags = ((struct virtio_net_common_hdr *)buf)->hdr.flags;
- if (vi->mergeable_rx_bufs)
+ switch (vi->mode) {
+ case VIRTNET_MODE_MERGE:
skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
stats);
- else if (vi->big_packets)
+ break;
+
+ case VIRTNET_MODE_BIG:
skb = receive_big(dev, vi, rq, buf, len, stats);
- else
+ break;
+
+ case VIRTNET_MODE_SMALL:
skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit,
stats);
+ break;
+ }
if (unlikely(!skb))
return;
@@ -2580,12 +2599,19 @@ static bool try_fill_recv(struct virtnet_info *vi,
struct receive_queue *rq,
}
do {
- if (vi->mergeable_rx_bufs)
+ switch (vi->mode) {
+ case VIRTNET_MODE_MERGE:
err = add_recvbuf_mergeable(vi, rq, gfp);
- else if (vi->big_packets)
+ break;
+
+ case VIRTNET_MODE_BIG:
err = add_recvbuf_big(vi, rq, gfp);
- else
+ break;
+
+ case VIRTNET_MODE_SMALL:
err = add_recvbuf_small(vi, rq, gfp);
+ break;
+ }
if (err)
break;
@@ -2703,7 +2729,7 @@ static int virtnet_receive_packets(struct virtnet_info
*vi,
int packets = 0;
void *buf;
- if (!vi->big_packets || vi->mergeable_rx_bufs) {
+ if (vi->mode != VIRTNET_MODE_BIG) {
void *ctx;
while (packets < budget &&
(buf = virtnet_rq_get_buf(rq, &len, &ctx))) {
@@ -5510,7 +5536,7 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
/* In big_packets mode, xdp cannot work, so there is no need to
* initialize xsk of rq.
*/
- if (vi->big_packets && !vi->mergeable_rx_bufs)
+ if (vi->mode == VIRTNET_MODE_BIG)
return -ENOENT;
if (qid >= vi->curr_queue_pairs)
@@ -6007,7 +6033,7 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
vqs_info = kcalloc(total_vqs, sizeof(*vqs_info), GFP_KERNEL);
if (!vqs_info)
goto err_vqs_info;
- if (!vi->big_packets || vi->mergeable_rx_bufs) {
+ if (vi->mode != VIRTNET_MODE_BIG) {
ctx = kcalloc(total_vqs, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
goto err_ctx;
@@ -6480,6 +6506,13 @@ static int virtnet_probe(struct virtio_device *vdev)
virtnet_set_big_packets(vi, mtu);
+ if (vi->mergeable_rx_bufs)
+ vi->mode = VIRTNET_MODE_MERGE;
+ else if (vi->big_packets)
+ vi->mode = VIRTNET_MODE_BIG;
+ else
+ vi->mode = VIRTNET_MODE_SMALL;
+
if (vi->any_header_sg)
dev->needed_headroom = vi->hdr_len;
--
2.32.0.3.g01195cf9f
