Build the xdp_buff by accumulating all the descriptors that make up a frame, so the XDP program runs on the full (possibly fragmented) packet instead of just the first buffer. When the frame is not consumed by the program, assemble the skb from the head buffer and the collected fragments via napi_build_skb()/xdp_update_skb_frags_info(). To do so, store the in-progress xdp_buff in rx_q->state instead of the partially built skb, so the accumulated head and fragments survive a NAPI poll boundary (mid-frame dma_own or dirty_rx break). The state is saved only while a frame is in progress and cleared as soon as it completes. In addition: - build the skb head with napi_build_skb() passing xdp->frame_sz, so skb_shinfo() lands on the same shared_info the fragments were accumulated into; - release all buffers belonging to a frame when it is dropped on RX errors, instead of leaking the ones already attached to the xdp_buff; - cap the number of fragments at MAX_SKB_FRAGS, returning any excess page to the page pool; - skip zero-length fragments, which can happen for non-first descriptors when split-header (SPH) is enabled. Signed-off-by: Lorenzo Bianconi --- drivers/net/ethernet/stmicro/stmmac/stmmac.h | 2 +- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 180 +++++++++++++++------- 2 files changed, 122 insertions(+), 60 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h index 4fc96b317d79..69bdbbf4b920 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h @@ -132,7 +132,7 @@ struct stmmac_rx_queue { dma_addr_t dma_rx_phy; unsigned int state_saved; struct { - struct sk_buff *skb; + struct xdp_buff xdp; unsigned int len; unsigned int error; } state; diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index bf9e7e4cb1c3..1de8d9626c64 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -1695,7 +1695,8 @@ static int stmmac_init_rx_buffers(struct stmmac_priv *priv, if (!buf->sec_page) return -ENOMEM; - buf->sec_addr = page_pool_get_dma_addr(buf->sec_page); + buf->sec_addr = page_pool_get_dma_addr(buf->sec_page) + + buf->page_offset; stmmac_set_desc_sec_addr(priv, p, buf->sec_addr, true); } else { buf->sec_page = NULL; @@ -5140,7 +5141,8 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv, u32 queue) if (!buf->sec_page) break; - buf->sec_addr = page_pool_get_dma_addr(buf->sec_page); + buf->sec_addr = page_pool_get_dma_addr(buf->sec_page) + + buf->page_offset; } buf->addr = page_pool_get_dma_addr(buf->page) + buf->page_offset; @@ -5735,6 +5737,82 @@ static int stmmac_rx_zc(struct stmmac_priv *priv, int limit, u32 queue) return failure ? limit : (int)count; } +static void +stmmac_xdp_put_buff(struct stmmac_rx_queue *rx_q, struct xdp_buff *xdp, + int sync_len) +{ + struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); + int i; + + if (likely(!xdp_buff_has_frags(xdp))) + goto out; + + for (i = 0; i < sinfo->nr_frags; i++) + page_pool_put_full_page(rx_q->page_pool, + skb_frag_page(&sinfo->frags[i]), true); +out: + page_pool_put_page(rx_q->page_pool, virt_to_head_page(xdp->data), + sync_len, true); +} + +static struct sk_buff *stmmac_build_skb(struct xdp_buff *xdp) +{ + struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); + u32 metasize = xdp->data - xdp->data_meta; + struct sk_buff *skb; + u8 num_frags; + + if (unlikely(xdp_buff_has_frags(xdp))) + num_frags = sinfo->nr_frags; + + skb = napi_build_skb(xdp->data_hard_start, xdp->frame_sz); + if (!skb) + return ERR_PTR(-ENOMEM); + + skb_mark_for_recycle(skb); + skb_reserve(skb, xdp->data - xdp->data_hard_start); + skb_put(skb, xdp->data_end - xdp->data); + if (metasize) + skb_metadata_set(skb, metasize); + + if (unlikely(xdp_buff_has_frags(xdp))) + xdp_update_skb_frags_info(skb, num_frags, sinfo->xdp_frags_size, + num_frags * xdp->frame_sz, + xdp_buff_get_skb_flags(xdp)); + return skb; +} + +static void stmmac_build_xdp_frags(struct stmmac_priv *priv, + struct stmmac_rx_queue *rx_q, + unsigned int len, struct page *page, + unsigned int offset, + enum dma_data_direction dma_dir, + struct xdp_buff *xdp) +{ + struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); + dma_addr_t dma_addr = page_pool_get_dma_addr(page) + offset; + + dma_sync_single_for_cpu(priv->device, dma_addr, len, dma_dir); + + if (!xdp_buff_has_frags(xdp)) { + xdp_buff_set_frags_flag(xdp); + sinfo->xdp_frags_size = 0; + sinfo->nr_frags = 0; + } + + if (sinfo->nr_frags < MAX_SKB_FRAGS) { + skb_frag_t *frag = &sinfo->frags[sinfo->nr_frags++]; + + skb_frag_fill_page_desc(frag, page, offset, len); + sinfo->xdp_frags_size += len; + + if (page_is_pfmemalloc(page)) + xdp_buff_set_frag_pfmemalloc(xdp); + } else { + page_pool_put_full_page(rx_q->page_pool, page, true); + } +} + /** * stmmac_rx - manage the receive process * @priv: driver private structure @@ -5756,11 +5834,12 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) unsigned int desc_size; struct sk_buff *skb = NULL; struct stmmac_xdp_buff ctx; + bool first_desc = true; int xdp_status = 0; int bufsz; dma_dir = page_pool_get_dma_dir(rx_q->page_pool); - bufsz = DIV_ROUND_UP(priv->dma_conf.dma_buf_sz, PAGE_SIZE) * PAGE_SIZE; + bufsz = rx_q->napi_skb_frag_size; if (netif_msg_rx_status(priv)) { void *rx_head = stmmac_get_rx_desc(priv, rx_q, 0); @@ -5780,9 +5859,10 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) u32 hash; if (!count && rx_q->state_saved) { - skb = rx_q->state.skb; + ctx.xdp = rx_q->state.xdp; error = rx_q->state.error; len = rx_q->state.len; + first_desc = false; } else { rx_q->state_saved = false; skb = NULL; @@ -5831,6 +5911,10 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) if (unlikely(error && (status & rx_not_ls))) goto read_again; if (unlikely(error)) { + if (!first_desc) { + stmmac_xdp_put_buff(rx_q, &ctx.xdp, -1); + first_desc = true; + } dev_kfree_skb(skb); skb = NULL; count++; @@ -5855,9 +5939,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) } } - if (!skb) { - unsigned int pre_len, sync_len; - + if (first_desc) { dma_sync_single_for_cpu(priv->device, buf->addr, buf1_len, dma_dir); net_prefetch(page_address(buf->page) + @@ -5866,6 +5948,28 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) xdp_init_buff(&ctx.xdp, bufsz, &rx_q->xdp_rxq); xdp_prepare_buff(&ctx.xdp, page_address(buf->page), buf->page_offset, buf1_len, true); + first_desc = false; + buf->page = NULL; + } else if (buf1_len) { + stmmac_build_xdp_frags(priv, rx_q, buf1_len, buf->page, + buf->page_offset, dma_dir, + &ctx.xdp); + buf->page = NULL; + } + + if (buf2_len) { + stmmac_build_xdp_frags(priv, rx_q, buf2_len, + buf->sec_page, buf->page_offset, + dma_dir, &ctx.xdp); + buf->sec_page = NULL; + } + + if (likely(status & rx_not_ls)) + goto read_again; + + first_desc = true; + if (!skb) { + unsigned int pre_len, sync_len; pre_len = ctx.xdp.data_end - ctx.xdp.data_hard_start - buf->page_offset; @@ -5887,10 +5991,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) unsigned int xdp_res = -PTR_ERR(skb); if (xdp_res & STMMAC_XDP_CONSUMED) { - page_pool_put_page(rx_q->page_pool, - virt_to_head_page(ctx.xdp.data), - sync_len, true); - buf->page = NULL; + stmmac_xdp_put_buff(rx_q, &ctx.xdp, sync_len); rx_dropped++; /* Clear skb as it was set as @@ -5906,7 +6007,6 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) } else if (xdp_res & (STMMAC_XDP_TX | STMMAC_XDP_REDIRECT)) { xdp_status |= xdp_res; - buf->page = NULL; skb = NULL; count++; continue; @@ -5914,51 +6014,13 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) } } - if (!skb) { - unsigned int head_pad_len; - - /* XDP program may expand or reduce tail */ - buf1_len = ctx.xdp.data_end - ctx.xdp.data; - - skb = napi_build_skb(page_address(buf->page), - rx_q->napi_skb_frag_size); - if (!skb) { - page_pool_recycle_direct(rx_q->page_pool, - buf->page); - rx_dropped++; - count++; - goto drain_data; - } - - /* XDP program may adjust header */ - head_pad_len = ctx.xdp.data - ctx.xdp.data_hard_start; - skb_reserve(skb, head_pad_len); - skb_put(skb, buf1_len); - skb_mark_for_recycle(skb); - buf->page = NULL; - } else if (buf1_len) { - dma_sync_single_for_cpu(priv->device, buf->addr, - buf1_len, dma_dir); - skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, - buf->page, buf->page_offset, buf1_len, - priv->dma_conf.dma_buf_sz); - buf->page = NULL; - } - - if (buf2_len) { - dma_sync_single_for_cpu(priv->device, buf->sec_addr, - buf2_len, dma_dir); - skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, - buf->sec_page, 0, buf2_len, - priv->dma_conf.dma_buf_sz); - buf->sec_page = NULL; - } - -drain_data: - if (likely(status & rx_not_ls)) + skb = stmmac_build_skb(&ctx.xdp); + if (IS_ERR(skb)) { + stmmac_xdp_put_buff(rx_q, &ctx.xdp, -1); + rx_dropped++; + count++; goto read_again; - if (!skb) - continue; + } /* Got entire packet into SKB. Finish it. */ @@ -5991,9 +6053,9 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) count++; } - if (status & rx_not_ls || skb) { - rx_q->state_saved = true; - rx_q->state.skb = skb; + rx_q->state_saved = !first_desc; + if (!first_desc) { + rx_q->state.xdp = ctx.xdp; rx_q->state.error = error; rx_q->state.len = len; } --- base-commit: 4bb9710c6a68d35207f123aef55dcd50e7195ec5 change-id: 20260918-stmmac-rx-mb-16469a2714ea Best regards, -- Lorenzo Bianconi