[PATCH v9 bpf-next 05/14] net: mvneta: add multi buffer support to XDP_TX

Lorenzo Bianconi
2021-06-14T12:50:57Z

Introduce the capability to map non-linear xdp buffer running
mvneta_xdp_submit_frame() for XDP_TX and XDP_REDIRECT

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
drivers/net/ethernet/marvell/mvneta.c | 112 +++++++++++++++++---------
1 file changed, 76 insertions(+), 36 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index f8993f7488b9..ab57be38ba03 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -1860,8 +1860,8 @@ static void mvneta_txq_bufs_free(struct mvneta_port *pp,
bytes_compl += buf->skb->len;
pkts_compl++;
dev_kfree_skb_any(buf->skb);
- } else if (buf->type == MVNETA_TYPE_XDP_TX ||
- buf->type == MVNETA_TYPE_XDP_NDO) {
+ } else if ((buf->type == MVNETA_TYPE_XDP_TX ||
+ buf->type == MVNETA_TYPE_XDP_NDO) && buf->xdpf) {
if (napi && buf->type == MVNETA_TYPE_XDP_TX)
xdp_return_frame_rx_napi(buf->xdpf);
else
@@ -2055,47 +2055,87 @@ mvneta_xdp_put_buff(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,

static int
mvneta_xdp_submit_frame(struct mvneta_port *pp, struct mvneta_tx_queue *txq,
- struct xdp_frame *xdpf, bool dma_map)
+ struct xdp_frame *xdpf, int *nxmit_byte, bool dma_map)
{
- struct mvneta_tx_desc *tx_desc;
- struct mvneta_tx_buf *buf;
- dma_addr_t dma_addr;
+ struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf);
+ struct device *dev = pp->dev->dev.parent;
+ struct mvneta_tx_desc *tx_desc = NULL;
+ int i, num_frames = 1;
+ struct page *page;
+
+ if (unlikely(xdp_frame_is_mb(xdpf)))
+ num_frames += sinfo->nr_frags;

- if (txq->count >= txq->tx_stop_threshold)
+ if (txq->count + num_frames >= txq->size)
return MVNETA_XDP_DROPPED;

- tx_desc = mvneta_txq_next_desc_get(txq);
+ for (i = 0; i < num_frames; i++) {
+ struct mvneta_tx_buf *buf = &txq->buf[txq->txq_put_index];
+ skb_frag_t *frag = NULL;
+ int len = xdpf->len;
+ dma_addr_t dma_addr;

- buf = &txq->buf[txq->txq_put_index];
- if (dma_map) {
- /* ndo_xdp_xmit */
- dma_addr = dma_map_single(pp->dev->dev.parent, xdpf->data,
- xdpf->len, DMA_TO_DEVICE);
- if (dma_mapping_error(pp->dev->dev.parent, dma_addr)) {
- mvneta_txq_desc_put(txq);
- return MVNETA_XDP_DROPPED;
+ if (unlikely(i)) { /* paged area */
+ frag = &sinfo->frags[i - 1];
+ len = skb_frag_size(frag);
}
- buf->type = MVNETA_TYPE_XDP_NDO;
- } else {
- struct page *page = virt_to_page(xdpf->data);

- dma_addr = page_pool_get_dma_addr(page) +
- sizeof(*xdpf) + xdpf->headroom;
- dma_sync_single_for_device(pp->dev->dev.parent, dma_addr,
- xdpf->len, DMA_BIDIRECTIONAL);
- buf->type = MVNETA_TYPE_XDP_TX;
+ tx_desc = mvneta_txq_next_desc_get(txq);
+ if (dma_map) {
+ /* ndo_xdp_xmit */
+ void *data;
+
+ data = unlikely(frag) ? skb_frag_address(frag)
+ : xdpf->data;
+ dma_addr = dma_map_single(dev, data, len,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, dma_addr)) {
+ mvneta_txq_desc_put(txq);
+ goto unmap;
+ }
+
+ buf->type = MVNETA_TYPE_XDP_NDO;
+ } else {
+ page = unlikely(frag) ? skb_frag_page(frag)
+ : virt_to_page(xdpf->data);
+ dma_addr = page_pool_get_dma_addr(page);
+ if (unlikely(frag))
+ dma_addr += skb_frag_off(frag);
+ else
+ dma_addr += sizeof(*xdpf) + xdpf->headroom;
+ dma_sync_single_for_device(dev, dma_addr, len,
+ DMA_BIDIRECTIONAL);
+ buf->type = MVNETA_TYPE_XDP_TX;
+ }
+ buf->xdpf = unlikely(i) ? NULL : xdpf;
+
+ tx_desc->command = unlikely(i) ? 0 : MVNETA_TXD_F_DESC;
+ tx_desc->buf_phys_addr = dma_addr;
+ tx_desc->data_size = len;
+ *nxmit_byte += len;
+
+ mvneta_txq_inc_put(txq);
}
- buf->xdpf = xdpf;

- tx_desc->command = MVNETA_TXD_FLZ_DESC;
- tx_desc->buf_phys_addr = dma_addr;
- tx_desc->data_size = xdpf->len;
+ /*last descriptor */
+ if (likely(tx_desc))
+ tx_desc->command |= MVNETA_TXD_L_DESC | MVNETA_TXD_Z_PAD;

- mvneta_txq_inc_put(txq);
- txq->pending++;
- txq->count++;
+ txq->pending += num_frames;
+ txq->count += num_frames;

return MVNETA_XDP_TX;
+
+unmap:
+ for (i--; i >= 0; i--) {
+ mvneta_txq_desc_put(txq);
+ tx_desc = txq->descs + txq->next_desc_to_proc;
+ dma_unmap_single(dev, tx_desc->buf_phys_addr,
+ tx_desc->data_size,
+ DMA_TO_DEVICE);
+ }
+
+ return MVNETA_XDP_DROPPED;
}

static int
@@ -2104,8 +2144,8 @@ mvneta_xdp_xmit_back(struct mvneta_port *pp, struct xdp_buff *xdp)
struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats);
struct mvneta_tx_queue *txq;
struct netdev_queue *nq;
+ int cpu, nxmit_byte = 0;
struct xdp_frame *xdpf;
- int cpu;
u32 ret;

xdpf = xdp_convert_buff_to_frame(xdp);
@@ -2117,10 +2157,10 @@ mvneta_xdp_xmit_back(struct mvneta_port *pp, struct xdp_buff *xdp)
nq = netdev_get_tx_queue(pp->dev, txq->id);

__netif_tx_lock(nq, cpu);
- ret = mvneta_xdp_submit_frame(pp, txq, xdpf, false);
+ ret = mvneta_xdp_submit_frame(pp, txq, xdpf, &nxmit_byte, false);
if (ret == MVNETA_XDP_TX) {
u64_stats_update_begin(&stats->syncp);
- stats->es.ps.tx_bytes += xdpf->len;
+ stats->es.ps.tx_bytes += nxmit_byte;
stats->es.ps.tx_packets++;
stats->es.ps.xdp_tx++;
u64_stats_update_end(&stats->syncp);
@@ -2159,11 +2199,11 @@ mvneta_xdp_xmit(struct net_device *dev, int num_frame,

__netif_tx_lock(nq, cpu);
for (i = 0; i < num_frame; i++) {
- ret = mvneta_xdp_submit_frame(pp, txq, frames[i], true);
+ ret = mvneta_xdp_submit_frame(pp, txq, frames[i], &nxmit_byte,
+ true);
if (ret != MVNETA_XDP_TX)
break;

- nxmit_byte += frames[i]->len;
nxmit++;
}

--
2.31.1