diff mbox series

[net-next,v1,4/4] virtio_net: rx remove premapped failover code

Message ID 20241029084615.91049-5-xuanzhuo@linux.alibaba.com (mailing list archive)
State Accepted
Commit fb22437c1ba37fc54eff949023923cc7887aaaa1
Delegated to: Netdev Maintainers
Headers show
Series virtio_net: enable premapped mode by default | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 10 of 10 maintainers
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 4 this patch: 4
netdev/checkpatch warning WARNING: Do not crash the kernel unless it is absolutely unavoidable--use WARN_ON_ONCE() plus recovery code (if feasible) instead of BUG() or variants WARNING: line length of 84 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-10-31--09-00 (tests: 779)

Commit Message

Xuan Zhuo Oct. 29, 2024, 8:46 a.m. UTC 
Now, the premapped mode can be enabled unconditionally.

So we can remove the failover code for merge and small mode.

The virtnet_rq_xxx() helper would be only used if the mode is using pre
mapping. A check is added to prevent misusing of these API.

Tested-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/net/virtio_net.c | 90 ++++++++++++++++++++--------------------
 1 file changed, 44 insertions(+), 46 deletions(-)

Comments

Jason Wang Nov. 5, 2024, 9:23 a.m. UTC | #1 
On Tue, Oct 29, 2024 at 4:47 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
>
> Now, the premapped mode can be enabled unconditionally.
>
> So we can remove the failover code for merge and small mode.
>
> The virtnet_rq_xxx() helper would be only used if the mode is using pre
> mapping. A check is added to prevent misusing of these API.
>
> Tested-by: Darren Kenny <darren.kenny@oracle.com>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

Acked-by: Jason Wang <jasowang@redhat.com>

Thanks
diff mbox series

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ea433e9650eb..169c1aa87da5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -356,9 +356,6 @@  struct receive_queue {
 	struct xdp_rxq_info xsk_rxq_info;
 
 	struct xdp_buff **xsk_buffs;
-
-	/* Do dma by self */
-	bool do_dma;
 };
 
 /* This structure can contain rss message with maximum settings for indirection table and keysize
@@ -856,11 +853,14 @@  static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 
 static void virtnet_rq_unmap(struct receive_queue *rq, void *buf, u32 len)
 {
+	struct virtnet_info *vi = rq->vq->vdev->priv;
 	struct page *page = virt_to_head_page(buf);
 	struct virtnet_rq_dma *dma;
 	void *head;
 	int offset;
 
+	BUG_ON(vi->big_packets && !vi->mergeable_rx_bufs);
+
 	head = page_address(page);
 
 	dma = head;
@@ -885,10 +885,13 @@  static void virtnet_rq_unmap(struct receive_queue *rq, void *buf, u32 len)
 
 static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx)
 {
+	struct virtnet_info *vi = rq->vq->vdev->priv;
 	void *buf;
 
+	BUG_ON(vi->big_packets && !vi->mergeable_rx_bufs);
+
 	buf = virtqueue_get_buf_ctx(rq->vq, len, ctx);
-	if (buf && rq->do_dma)
+	if (buf)
 		virtnet_rq_unmap(rq, buf, *len);
 
 	return buf;
@@ -896,15 +899,13 @@  static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx)
 
 static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len)
 {
+	struct virtnet_info *vi = rq->vq->vdev->priv;
 	struct virtnet_rq_dma *dma;
 	dma_addr_t addr;
 	u32 offset;
 	void *head;
 
-	if (!rq->do_dma) {
-		sg_init_one(rq->sg, buf, len);
-		return;
-	}
+	BUG_ON(vi->big_packets && !vi->mergeable_rx_bufs);
 
 	head = page_address(rq->alloc_frag.page);
 
@@ -922,50 +923,51 @@  static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len)
 static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp)
 {
 	struct page_frag *alloc_frag = &rq->alloc_frag;
+	struct virtnet_info *vi = rq->vq->vdev->priv;
 	struct virtnet_rq_dma *dma;
 	void *buf, *head;
 	dma_addr_t addr;
 
+	BUG_ON(vi->big_packets && !vi->mergeable_rx_bufs);
+
 	head = page_address(alloc_frag->page);
 
-	if (rq->do_dma) {
-		dma = head;
-
-		/* new pages */
-		if (!alloc_frag->offset) {
-			if (rq->last_dma) {
-				/* Now, the new page is allocated, the last dma
-				 * will not be used. So the dma can be unmapped
-				 * if the ref is 0.
-				 */
-				virtnet_rq_unmap(rq, rq->last_dma, 0);
-				rq->last_dma = NULL;
-			}
+	dma = head;
 
-			dma->len = alloc_frag->size - sizeof(*dma);
+	/* new pages */
+	if (!alloc_frag->offset) {
+		if (rq->last_dma) {
+			/* Now, the new page is allocated, the last dma
+			 * will not be used. So the dma can be unmapped
+			 * if the ref is 0.
+			 */
+			virtnet_rq_unmap(rq, rq->last_dma, 0);
+			rq->last_dma = NULL;
+		}
 
-			addr = virtqueue_dma_map_single_attrs(rq->vq, dma + 1,
-							      dma->len, DMA_FROM_DEVICE, 0);
-			if (virtqueue_dma_mapping_error(rq->vq, addr))
-				return NULL;
+		dma->len = alloc_frag->size - sizeof(*dma);
 
-			dma->addr = addr;
-			dma->need_sync = virtqueue_dma_need_sync(rq->vq, addr);
+		addr = virtqueue_dma_map_single_attrs(rq->vq, dma + 1,
+						      dma->len, DMA_FROM_DEVICE, 0);
+		if (virtqueue_dma_mapping_error(rq->vq, addr))
+			return NULL;
 
-			/* Add a reference to dma to prevent the entire dma from
-			 * being released during error handling. This reference
-			 * will be freed after the pages are no longer used.
-			 */
-			get_page(alloc_frag->page);
-			dma->ref = 1;
-			alloc_frag->offset = sizeof(*dma);
+		dma->addr = addr;
+		dma->need_sync = virtqueue_dma_need_sync(rq->vq, addr);
 
-			rq->last_dma = dma;
-		}
+		/* Add a reference to dma to prevent the entire dma from
+		 * being released during error handling. This reference
+		 * will be freed after the pages are no longer used.
+		 */
+		get_page(alloc_frag->page);
+		dma->ref = 1;
+		alloc_frag->offset = sizeof(*dma);
 
-		++dma->ref;
+		rq->last_dma = dma;
 	}
 
+	++dma->ref;
+
 	buf = head + alloc_frag->offset;
 
 	get_page(alloc_frag->page);
@@ -2433,8 +2435,7 @@  static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq,
 
 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
 	if (err < 0) {
-		if (rq->do_dma)
-			virtnet_rq_unmap(rq, buf, 0);
+		virtnet_rq_unmap(rq, buf, 0);
 		put_page(virt_to_head_page(buf));
 	}
 
@@ -2554,8 +2555,7 @@  static int add_recvbuf_mergeable(struct virtnet_info *vi,
 	ctx = mergeable_len_to_ctx(len + room, headroom);
 	err = virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp);
 	if (err < 0) {
-		if (rq->do_dma)
-			virtnet_rq_unmap(rq, buf, 0);
+		virtnet_rq_unmap(rq, buf, 0);
 		put_page(virt_to_head_page(buf));
 	}
 
@@ -5922,7 +5922,7 @@  static void free_receive_page_frags(struct virtnet_info *vi)
 	int i;
 	for (i = 0; i < vi->max_queue_pairs; i++)
 		if (vi->rq[i].alloc_frag.page) {
-			if (vi->rq[i].do_dma && vi->rq[i].last_dma)
+			if (vi->rq[i].last_dma)
 				virtnet_rq_unmap(&vi->rq[i], vi->rq[i].last_dma, 0);
 			put_page(vi->rq[i].alloc_frag.page);
 		}
@@ -6111,11 +6111,9 @@  static void virtnet_rq_set_premapped(struct virtnet_info *vi)
 {
 	int i;
 
-	for (i = 0; i < vi->max_queue_pairs; i++) {
+	for (i = 0; i < vi->max_queue_pairs; i++)
 		/* error should never happen */
 		BUG_ON(virtqueue_set_dma_premapped(vi->rq[i].vq));
-		vi->rq[i].do_dma = true;
-	}
 }
 
 static int init_vqs(struct virtnet_info *vi)