Skip to content

Commit

Permalink
net: mvneta: move skb build after descriptors processing
Browse files Browse the repository at this point in the history 
Move skb build after all descriptors processing. This is a preliminary
patch to enable multi-buffers and JUMBO frames support for XDP.
Introduce mvneta_xdp_put_buff routine to release all pages used by a
XDP multi-buffer

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
Lorenzo Bianconi authored and David S. Miller committed Jul 20, 2020
1 parent 2f0bc54 commit ca0e014
Showing 1 changed file with 101 additions and 57 deletions.
158 changes: 101 additions & 57 deletions drivers/net/ethernet/marvell/mvneta.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2026,6 +2026,20 @@ int mvneta_rx_refill_queue(struct mvneta_port *pp, struct mvneta_rx_queue *rxq)
return i;
}

static void
mvneta_xdp_put_buff(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
struct xdp_buff *xdp, int sync_len, bool napi)
{
struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
int i;

page_pool_put_page(rxq->page_pool, virt_to_head_page(xdp->data),
sync_len, napi);
for (i = 0; i < sinfo->nr_frags; i++)
page_pool_put_full_page(rxq->page_pool,
skb_frag_page(&sinfo->frags[i]), napi);
}

static int
mvneta_xdp_submit_frame(struct mvneta_port *pp, struct mvneta_tx_queue *txq,
struct xdp_frame *xdpf, bool dma_map)
Expand Down Expand Up @@ -2229,6 +2243,7 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp,
int data_len = -MVNETA_MH_SIZE, len;
struct net_device *dev = pp->dev;
enum dma_data_direction dma_dir;
struct skb_shared_info *sinfo;
int ret = 0;

if (MVNETA_SKB_SIZE(rx_desc->data_size) > PAGE_SIZE) {
Expand All @@ -2252,35 +2267,13 @@ mvneta_swbm_rx_frame(struct mvneta_port *pp,
xdp->data_end = xdp->data + data_len;
xdp_set_data_meta_invalid(xdp);

if (xdp_prog) {
ret = mvneta_run_xdp(pp, rxq, xdp_prog, xdp, stats);
if (ret)
goto out;
}

rxq->skb = build_skb(xdp->data_hard_start, PAGE_SIZE);
if (unlikely(!rxq->skb)) {
struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats);
sinfo = xdp_get_shared_info_from_buff(xdp);
sinfo->nr_frags = 0;

netdev_err(dev, "Can't allocate skb on queue %d\n", rxq->id);

u64_stats_update_begin(&stats->syncp);
stats->es.skb_alloc_error++;
stats->rx_dropped++;
u64_stats_update_end(&stats->syncp);

return -ENOMEM;
}
page_pool_release_page(rxq->page_pool, page);

skb_reserve(rxq->skb,
xdp->data - xdp->data_hard_start);
skb_put(rxq->skb, xdp->data_end - xdp->data);
mvneta_rx_csum(pp, rx_desc->status, rxq->skb);
if (xdp_prog)
ret = mvneta_run_xdp(pp, rxq, xdp_prog, xdp, stats);

rxq->left_size = rx_desc->data_size - len;

out:
rx_desc->buf_phys_addr = 0;

return ret;
Expand All @@ -2290,8 +2283,10 @@ static void
mvneta_swbm_add_rx_fragment(struct mvneta_port *pp,
struct mvneta_rx_desc *rx_desc,
struct mvneta_rx_queue *rxq,
struct xdp_buff *xdp,
struct page *page)
{
struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
struct net_device *dev = pp->dev;
enum dma_data_direction dma_dir;
int data_len, len;
Expand All @@ -2307,41 +2302,79 @@ mvneta_swbm_add_rx_fragment(struct mvneta_port *pp,
dma_sync_single_for_cpu(dev->dev.parent,
rx_desc->buf_phys_addr,
len, dma_dir);
if (data_len > 0) {
/* refill descriptor with new buffer later */
skb_add_rx_frag(rxq->skb,
skb_shinfo(rxq->skb)->nr_frags,
page, pp->rx_offset_correction, data_len,
PAGE_SIZE);
}
page_pool_release_page(rxq->page_pool, page);
rx_desc->buf_phys_addr = 0;

if (data_len > 0 && sinfo->nr_frags < MAX_SKB_FRAGS) {
skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags];

skb_frag_off_set(frag, pp->rx_offset_correction);
skb_frag_size_set(frag, data_len);
__skb_frag_set_page(frag, page);
sinfo->nr_frags++;

rx_desc->buf_phys_addr = 0;
}
rxq->left_size -= len;
}

static struct sk_buff *
mvneta_swbm_build_skb(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
struct xdp_buff *xdp, u32 desc_status)
{
struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
int i, num_frags = sinfo->nr_frags;
skb_frag_t frags[MAX_SKB_FRAGS];
struct sk_buff *skb;

memcpy(frags, sinfo->frags, sizeof(skb_frag_t) * num_frags);

skb = build_skb(xdp->data_hard_start, PAGE_SIZE);
if (!skb)
return ERR_PTR(-ENOMEM);

page_pool_release_page(rxq->page_pool, virt_to_page(xdp->data));

skb_reserve(skb, xdp->data - xdp->data_hard_start);
skb_put(skb, xdp->data_end - xdp->data);
mvneta_rx_csum(pp, desc_status, skb);

for (i = 0; i < num_frags; i++) {
struct page *page = skb_frag_page(&frags[i]);

skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
page, skb_frag_off(&frags[i]),
skb_frag_size(&frags[i]), PAGE_SIZE);
page_pool_release_page(rxq->page_pool, page);
}

return skb;
}

/* Main rx processing when using software buffer management */
static int mvneta_rx_swbm(struct napi_struct *napi,
struct mvneta_port *pp, int budget,
struct mvneta_rx_queue *rxq)
{
int rx_proc = 0, rx_todo, refill;
struct net_device *dev = pp->dev;
struct xdp_buff xdp_buf = {
.frame_sz = PAGE_SIZE,
.rxq = &rxq->xdp_rxq,
};
struct mvneta_stats ps = {};
struct bpf_prog *xdp_prog;
struct xdp_buff xdp_buf;
u32 desc_status;

/* Get number of received packets */
rx_todo = mvneta_rxq_busy_desc_num_get(pp, rxq);

rcu_read_lock();
xdp_prog = READ_ONCE(pp->xdp_prog);
xdp_buf.rxq = &rxq->xdp_rxq;
xdp_buf.frame_sz = PAGE_SIZE;

/* Fairness NAPI loop */
while (rx_proc < budget && rx_proc < rx_todo) {
struct mvneta_rx_desc *rx_desc = mvneta_rxq_next_desc_get(rxq);
u32 rx_status, index;
struct sk_buff *skb;
struct page *page;

index = rx_desc - rxq->descs;
Expand All @@ -2357,49 +2390,60 @@ static int mvneta_rx_swbm(struct napi_struct *napi,
/* Check errors only for FIRST descriptor */
if (rx_status & MVNETA_RXD_ERR_SUMMARY) {
mvneta_rx_error(pp, rx_desc);
/* leave the descriptor untouched */
continue;
goto next;
}

err = mvneta_swbm_rx_frame(pp, rx_desc, rxq, &xdp_buf,
xdp_prog, page, &ps);
if (err)
continue;

desc_status = rx_desc->status;
} else {
if (unlikely(!rxq->skb)) {
pr_debug("no skb for rx_status 0x%x\n",
rx_status);
if (unlikely(!xdp_buf.data_hard_start))
continue;
}
mvneta_swbm_add_rx_fragment(pp, rx_desc, rxq, page);

mvneta_swbm_add_rx_fragment(pp, rx_desc, rxq, &xdp_buf,
page);
} /* Middle or Last descriptor */

if (!(rx_status & MVNETA_RXD_LAST_DESC))
/* no last descriptor this time */
continue;

if (rxq->left_size) {
pr_err("get last desc, but left_size (%d) != 0\n",
rxq->left_size);
dev_kfree_skb_any(rxq->skb);
rxq->left_size = 0;
rxq->skb = NULL;
continue;
mvneta_xdp_put_buff(pp, rxq, &xdp_buf, -1, true);
goto next;
}

ps.rx_bytes += rxq->skb->len;
ps.rx_packets++;
skb = mvneta_swbm_build_skb(pp, rxq, &xdp_buf, desc_status);
if (IS_ERR(skb)) {
struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats);

/* Linux processing */
rxq->skb->protocol = eth_type_trans(rxq->skb, dev);
mvneta_xdp_put_buff(pp, rxq, &xdp_buf, -1, true);

u64_stats_update_begin(&stats->syncp);
stats->es.skb_alloc_error++;
stats->rx_dropped++;
u64_stats_update_end(&stats->syncp);

goto next;
}

napi_gro_receive(napi, rxq->skb);
ps.rx_bytes += skb->len;
ps.rx_packets++;

/* clean uncomplete skb pointer in queue */
rxq->skb = NULL;
skb->protocol = eth_type_trans(skb, dev);
napi_gro_receive(napi, skb);
next:
xdp_buf.data_hard_start = NULL;
}
rcu_read_unlock();

if (xdp_buf.data_hard_start)
mvneta_xdp_put_buff(pp, rxq, &xdp_buf, -1, true);

if (ps.xdp_redirect)
xdp_do_flush_map();

Expand Down

0 comments on commit ca0e014

Please sign in to comment.