From: Tirthendu Sarkar Date: Thu, 9 Mar 2023 18:56:15 +0000 (+0530) Subject: i40e: add support for XDP multi-buffer Rx X-Git-Tag: v6.4-rc1~77^2~354^2 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=e213ced19bef;p=linux-2.6-block.git i40e: add support for XDP multi-buffer Rx This patch adds multi-buffer support for the i40e_driver. i40e_clean_rx_irq() is modified to collate all the buffers of a packet before calling the XDP program. xdp_buff is built for the first frag of the packet and subsequent frags are added to it. 'next_to_process' is incremented for all non-EOP frags while 'next_to_clean' stays at the first descriptor of the packet. XDP program is called only on receiving EOP frag. New functions are added for adding frags to xdp_buff and for post processing of the buffers once the xdp prog has run. For XDP_PASS this results in a skb with multiple fragments. i40e_build_skb() builds the skb around xdp buffer that already contains frags data. So i40e_add_rx_frag() helper function is now removed. Since fields before 'dataref' in skb_shared_info are cleared during napi_skb_build(), xdp_update_skb_shared_info() is called to set those. For i40e_construct_skb(), all the frags data needs to be copied from xdp_buffer's shared_skb_info to newly constructed skb's shared_skb_info. This also means 'skb' does not need to be preserved across i40e_napi_poll() calls and hence is removed from i40e_ring structure. Previously i40e_alloc_rx_buffers() was called for every 32 cleaned buffers. For multi-buffers this may not be optimal as there may be more cleaned buffers in each i40e_clean_rx_irq() call. So this is now called when at least half of the ring size has been cleaned. Signed-off-by: Tirthendu Sarkar Tested-by: Chandan Kumar Rout (A Contingent Worker at Intel) Signed-off-by: Tony Nguyen --- diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index f2c151a01e77..053be338e4ba 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -2919,7 +2919,7 @@ static int i40e_max_vsi_frame_size(struct i40e_vsi *vsi, u16 rx_buf_len = i40e_calculate_vsi_rx_buf_len(vsi); u16 chain_len; - if (xdp_prog) + if (xdp_prog && !xdp_prog->aux->xdp_has_frags) chain_len = 1; else chain_len = I40E_MAX_CHAINED_RX_BUFFERS; @@ -13337,7 +13337,7 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi, struct bpf_prog *prog, /* Don't allow frames that span over multiple buffers */ if (vsi->netdev->mtu > frame_size - I40E_PACKET_HDR_PAD) { - NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP"); + NL_SET_ERR_MSG_MOD(extack, "MTU too large for linear frames and XDP prog does not support frags"); return -EINVAL; } @@ -13823,7 +13823,8 @@ static int i40e_config_netdev(struct i40e_vsi *vsi) netdev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT | - NETDEV_XDP_ACT_XSK_ZEROCOPY; + NETDEV_XDP_ACT_XSK_ZEROCOPY | + NETDEV_XDP_ACT_RX_SG; } else { /* Relate the VSI_VMDQ name to the VSI_MAIN name. Note that we * are still limited by IFNAMSIZ, but we're adding 'v%d\0' to diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 5544c2d43a92..32cce90abbb4 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -1477,9 +1477,6 @@ void i40e_clean_rx_ring(struct i40e_ring *rx_ring) if (!rx_ring->rx_bi) return; - dev_kfree_skb(rx_ring->skb); - rx_ring->skb = NULL; - if (rx_ring->xsk_pool) { i40e_xsk_clean_rx_ring(rx_ring); goto skip_free; @@ -2033,36 +2030,6 @@ static void i40e_rx_buffer_flip(struct i40e_rx_buffer *rx_buffer, #endif } -/** - * i40e_add_rx_frag - Add contents of Rx buffer to sk_buff - * @rx_ring: rx descriptor ring to transact packets on - * @rx_buffer: buffer containing page to add - * @skb: sk_buff to place the data into - * @size: packet length from rx_desc - * - * This function will add the data contained in rx_buffer->page to the skb. - * It will just attach the page as a frag to the skb. - * - * The function will then update the page offset. - **/ -static void i40e_add_rx_frag(struct i40e_ring *rx_ring, - struct i40e_rx_buffer *rx_buffer, - struct sk_buff *skb, - unsigned int size) -{ -#if (PAGE_SIZE < 8192) - unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2; -#else - unsigned int truesize = SKB_DATA_ALIGN(size + rx_ring->rx_offset); -#endif - - skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page, - rx_buffer->page_offset, size, truesize); - - /* page is being used so we must update the page offset */ - i40e_rx_buffer_flip(rx_buffer, truesize); -} - /** * i40e_get_rx_buffer - Fetch Rx buffer and synchronize data for use * @rx_ring: rx descriptor ring to transact packets on @@ -2099,20 +2066,82 @@ static struct i40e_rx_buffer *i40e_get_rx_buffer(struct i40e_ring *rx_ring, } /** - * i40e_construct_skb - Allocate skb and populate it + * i40e_put_rx_buffer - Clean up used buffer and either recycle or free * @rx_ring: rx descriptor ring to transact packets on * @rx_buffer: rx buffer to pull data from + * + * This function will clean up the contents of the rx_buffer. It will + * either recycle the buffer or unmap it and free the associated resources. + */ +static void i40e_put_rx_buffer(struct i40e_ring *rx_ring, + struct i40e_rx_buffer *rx_buffer) +{ + if (i40e_can_reuse_rx_page(rx_buffer, &rx_ring->rx_stats)) { + /* hand second half of page back to the ring */ + i40e_reuse_rx_page(rx_ring, rx_buffer); + } else { + /* we are not reusing the buffer so unmap it */ + dma_unmap_page_attrs(rx_ring->dev, rx_buffer->dma, + i40e_rx_pg_size(rx_ring), + DMA_FROM_DEVICE, I40E_RX_DMA_ATTR); + __page_frag_cache_drain(rx_buffer->page, + rx_buffer->pagecnt_bias); + /* clear contents of buffer_info */ + rx_buffer->page = NULL; + } +} + +/** + * i40e_process_rx_buffs- Processing of buffers post XDP prog or on error + * @rx_ring: Rx descriptor ring to transact packets on + * @xdp_res: Result of the XDP program + * @xdp: xdp_buff pointing to the data + **/ +static void i40e_process_rx_buffs(struct i40e_ring *rx_ring, int xdp_res, + struct xdp_buff *xdp) +{ + u32 next = rx_ring->next_to_clean; + struct i40e_rx_buffer *rx_buffer; + + xdp->flags = 0; + + while (1) { + rx_buffer = i40e_rx_bi(rx_ring, next); + if (++next == rx_ring->count) + next = 0; + + if (!rx_buffer->page) + continue; + + if (xdp_res == I40E_XDP_CONSUMED) + rx_buffer->pagecnt_bias++; + else + i40e_rx_buffer_flip(rx_buffer, xdp->frame_sz); + + /* EOP buffer will be put in i40e_clean_rx_irq() */ + if (next == rx_ring->next_to_process) + return; + + i40e_put_rx_buffer(rx_ring, rx_buffer); + } +} + +/** + * i40e_construct_skb - Allocate skb and populate it + * @rx_ring: rx descriptor ring to transact packets on * @xdp: xdp_buff pointing to the data + * @nr_frags: number of buffers for the packet * * This function allocates an skb. It then populates it with the page * data from the current receive descriptor, taking care to set up the * skb correctly. */ static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring, - struct i40e_rx_buffer *rx_buffer, - struct xdp_buff *xdp) + struct xdp_buff *xdp, + u32 nr_frags) { unsigned int size = xdp->data_end - xdp->data; + struct i40e_rx_buffer *rx_buffer; unsigned int headlen; struct sk_buff *skb; @@ -2152,13 +2181,17 @@ static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring, memcpy(__skb_put(skb, headlen), xdp->data, ALIGN(headlen, sizeof(long))); + rx_buffer = i40e_rx_bi(rx_ring, rx_ring->next_to_clean); /* update all of the pointers */ size -= headlen; if (size) { + if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { + dev_kfree_skb(skb); + return NULL; + } skb_add_rx_frag(skb, 0, rx_buffer->page, rx_buffer->page_offset + headlen, size, xdp->frame_sz); - /* buffer is used by skb, update page_offset */ i40e_rx_buffer_flip(rx_buffer, xdp->frame_sz); } else { @@ -2166,21 +2199,40 @@ static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring, rx_buffer->pagecnt_bias++; } + if (unlikely(xdp_buff_has_frags(xdp))) { + struct skb_shared_info *sinfo, *skinfo = skb_shinfo(skb); + + sinfo = xdp_get_shared_info_from_buff(xdp); + memcpy(&skinfo->frags[skinfo->nr_frags], &sinfo->frags[0], + sizeof(skb_frag_t) * nr_frags); + + xdp_update_skb_shared_info(skb, skinfo->nr_frags + nr_frags, + sinfo->xdp_frags_size, + nr_frags * xdp->frame_sz, + xdp_buff_is_frag_pfmemalloc(xdp)); + + /* First buffer has already been processed, so bump ntc */ + if (++rx_ring->next_to_clean == rx_ring->count) + rx_ring->next_to_clean = 0; + + i40e_process_rx_buffs(rx_ring, I40E_XDP_PASS, xdp); + } + return skb; } /** * i40e_build_skb - Build skb around an existing buffer * @rx_ring: Rx descriptor ring to transact packets on - * @rx_buffer: Rx buffer to pull data from * @xdp: xdp_buff pointing to the data + * @nr_frags: number of buffers for the packet * * This function builds an skb around an existing Rx buffer, taking care * to set up the skb correctly and avoid any memcpy overhead. */ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring, - struct i40e_rx_buffer *rx_buffer, - struct xdp_buff *xdp) + struct xdp_buff *xdp, + u32 nr_frags) { unsigned int metasize = xdp->data - xdp->data_meta; struct sk_buff *skb; @@ -2203,36 +2255,25 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring, if (metasize) skb_metadata_set(skb, metasize); - /* buffer is used by skb, update page_offset */ - i40e_rx_buffer_flip(rx_buffer, xdp->frame_sz); + if (unlikely(xdp_buff_has_frags(xdp))) { + struct skb_shared_info *sinfo; - return skb; -} + sinfo = xdp_get_shared_info_from_buff(xdp); + xdp_update_skb_shared_info(skb, nr_frags, + sinfo->xdp_frags_size, + nr_frags * xdp->frame_sz, + xdp_buff_is_frag_pfmemalloc(xdp)); -/** - * i40e_put_rx_buffer - Clean up used buffer and either recycle or free - * @rx_ring: rx descriptor ring to transact packets on - * @rx_buffer: rx buffer to pull data from - * - * This function will clean up the contents of the rx_buffer. It will - * either recycle the buffer or unmap it and free the associated resources. - */ -static void i40e_put_rx_buffer(struct i40e_ring *rx_ring, - struct i40e_rx_buffer *rx_buffer) -{ - if (i40e_can_reuse_rx_page(rx_buffer, &rx_ring->rx_stats)) { - /* hand second half of page back to the ring */ - i40e_reuse_rx_page(rx_ring, rx_buffer); + i40e_process_rx_buffs(rx_ring, I40E_XDP_PASS, xdp); } else { - /* we are not reusing the buffer so unmap it */ - dma_unmap_page_attrs(rx_ring->dev, rx_buffer->dma, - i40e_rx_pg_size(rx_ring), - DMA_FROM_DEVICE, I40E_RX_DMA_ATTR); - __page_frag_cache_drain(rx_buffer->page, - rx_buffer->pagecnt_bias); - /* clear contents of buffer_info */ - rx_buffer->page = NULL; + struct i40e_rx_buffer *rx_buffer; + + rx_buffer = i40e_rx_bi(rx_ring, rx_ring->next_to_clean); + /* buffer is used by skb, update page_offset */ + i40e_rx_buffer_flip(rx_buffer, xdp->frame_sz); } + + return skb; } /** @@ -2387,6 +2428,55 @@ static void i40e_inc_ntp(struct i40e_ring *rx_ring) prefetch(I40E_RX_DESC(rx_ring, ntp)); } +/** + * i40e_add_xdp_frag: Add a frag to xdp_buff + * @xdp: xdp_buff pointing to the data + * @nr_frags: return number of buffers for the packet + * @rx_buffer: rx_buffer holding data of the current frag + * @size: size of data of current frag + */ +static int i40e_add_xdp_frag(struct xdp_buff *xdp, u32 *nr_frags, + struct i40e_rx_buffer *rx_buffer, u32 size) +{ + struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); + + if (!xdp_buff_has_frags(xdp)) { + sinfo->nr_frags = 0; + sinfo->xdp_frags_size = 0; + xdp_buff_set_frags_flag(xdp); + } else if (unlikely(sinfo->nr_frags >= MAX_SKB_FRAGS)) { + /* Overflowing packet: All frags need to be dropped */ + return -ENOMEM; + } + + __skb_fill_page_desc_noacc(sinfo, sinfo->nr_frags++, rx_buffer->page, + rx_buffer->page_offset, size); + + sinfo->xdp_frags_size += size; + + if (page_is_pfmemalloc(rx_buffer->page)) + xdp_buff_set_frag_pfmemalloc(xdp); + *nr_frags = sinfo->nr_frags; + + return 0; +} + +/** + * i40e_consume_xdp_buff - Consume all the buffers of the packet and update ntc + * @rx_ring: rx descriptor ring to transact packets on + * @xdp: xdp_buff pointing to the data + * @rx_buffer: rx_buffer of eop desc + */ +static void i40e_consume_xdp_buff(struct i40e_ring *rx_ring, + struct xdp_buff *xdp, + struct i40e_rx_buffer *rx_buffer) +{ + i40e_process_rx_buffs(rx_ring, I40E_XDP_CONSUMED, xdp); + i40e_put_rx_buffer(rx_ring, rx_buffer); + rx_ring->next_to_clean = rx_ring->next_to_process; + xdp->data = NULL; +} + /** * i40e_clean_rx_irq - Clean completed descriptors from Rx ring - bounce buf * @rx_ring: rx descriptor ring to transact packets on @@ -2405,9 +2495,9 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget, { unsigned int total_rx_bytes = 0, total_rx_packets = 0; u16 cleaned_count = I40E_DESC_UNUSED(rx_ring); + u16 clean_threshold = rx_ring->count / 2; unsigned int offset = rx_ring->rx_offset; struct xdp_buff *xdp = &rx_ring->xdp; - struct sk_buff *skb = rx_ring->skb; unsigned int xdp_xmit = 0; struct bpf_prog *xdp_prog; bool failure = false; @@ -2419,11 +2509,14 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget, u16 ntp = rx_ring->next_to_process; struct i40e_rx_buffer *rx_buffer; union i40e_rx_desc *rx_desc; + struct sk_buff *skb; unsigned int size; + u32 nfrags = 0; + bool neop; u64 qword; /* return some buffers to hardware, one at a time is too slow */ - if (cleaned_count >= I40E_RX_BUFFER_WRITE) { + if (cleaned_count >= clean_threshold) { failure = failure || i40e_alloc_rx_buffers(rx_ring, cleaned_count); cleaned_count = 0; @@ -2461,76 +2554,83 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget, break; i40e_trace(clean_rx_irq, rx_ring, rx_desc, xdp); + /* retrieve a buffer from the ring */ rx_buffer = i40e_get_rx_buffer(rx_ring, size); - /* retrieve a buffer from the ring */ - if (!skb) { + neop = i40e_is_non_eop(rx_ring, rx_desc); + i40e_inc_ntp(rx_ring); + + if (!xdp->data) { unsigned char *hard_start; hard_start = page_address(rx_buffer->page) + rx_buffer->page_offset - offset; xdp_prepare_buff(xdp, hard_start, offset, size, true); - xdp_buff_clear_frags_flag(xdp); #if (PAGE_SIZE > 4096) /* At larger PAGE_SIZE, frame_sz depend on len size */ xdp->frame_sz = i40e_rx_frame_truesize(rx_ring, size); #endif - xdp_res = i40e_run_xdp(rx_ring, xdp, xdp_prog); + } else if (i40e_add_xdp_frag(xdp, &nfrags, rx_buffer, size) && + !neop) { + /* Overflowing packet: Drop all frags on EOP */ + i40e_consume_xdp_buff(rx_ring, xdp, rx_buffer); + break; } + if (neop) + continue; + + xdp_res = i40e_run_xdp(rx_ring, xdp, xdp_prog); + if (xdp_res) { - if (xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR)) { - xdp_xmit |= xdp_res; + xdp_xmit |= xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR); + + if (unlikely(xdp_buff_has_frags(xdp))) { + i40e_process_rx_buffs(rx_ring, xdp_res, xdp); + size = xdp_get_buff_len(xdp); + } else if (xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR)) { i40e_rx_buffer_flip(rx_buffer, xdp->frame_sz); } else { rx_buffer->pagecnt_bias++; } total_rx_bytes += size; - total_rx_packets++; - } else if (skb) { - i40e_add_rx_frag(rx_ring, rx_buffer, skb, size); - } else if (ring_uses_build_skb(rx_ring)) { - skb = i40e_build_skb(rx_ring, rx_buffer, xdp); } else { - skb = i40e_construct_skb(rx_ring, rx_buffer, xdp); - } + if (ring_uses_build_skb(rx_ring)) + skb = i40e_build_skb(rx_ring, xdp, nfrags); + else + skb = i40e_construct_skb(rx_ring, xdp, nfrags); + + /* drop if we failed to retrieve a buffer */ + if (!skb) { + rx_ring->rx_stats.alloc_buff_failed++; + i40e_consume_xdp_buff(rx_ring, xdp, rx_buffer); + break; + } - /* exit if we failed to retrieve a buffer */ - if (!xdp_res && !skb) { - rx_ring->rx_stats.alloc_buff_failed++; - rx_buffer->pagecnt_bias++; - break; - } + if (i40e_cleanup_headers(rx_ring, skb, rx_desc)) + goto process_next; - i40e_put_rx_buffer(rx_ring, rx_buffer); - cleaned_count++; + /* probably a little skewed due to removing CRC */ + total_rx_bytes += skb->len; - i40e_inc_ntp(rx_ring); - rx_ring->next_to_clean = rx_ring->next_to_process; - if (i40e_is_non_eop(rx_ring, rx_desc)) - continue; + /* populate checksum, VLAN, and protocol */ + i40e_process_skb_fields(rx_ring, rx_desc, skb); - if (xdp_res || i40e_cleanup_headers(rx_ring, skb, rx_desc)) { - skb = NULL; - continue; + i40e_trace(clean_rx_irq_rx, rx_ring, rx_desc, xdp); + napi_gro_receive(&rx_ring->q_vector->napi, skb); } - /* probably a little skewed due to removing CRC */ - total_rx_bytes += skb->len; - - /* populate checksum, VLAN, and protocol */ - i40e_process_skb_fields(rx_ring, rx_desc, skb); - - i40e_trace(clean_rx_irq_rx, rx_ring, rx_desc, xdp); - napi_gro_receive(&rx_ring->q_vector->napi, skb); - skb = NULL; - /* update budget accounting */ total_rx_packets++; +process_next: + cleaned_count += nfrags + 1; + i40e_put_rx_buffer(rx_ring, rx_buffer); + rx_ring->next_to_clean = rx_ring->next_to_process; + + xdp->data = NULL; } i40e_finalize_xdp_rx(rx_ring, xdp_xmit); - rx_ring->skb = skb; i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets); diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h index 55da9fde9d17..8c3d24012c54 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h @@ -392,14 +392,6 @@ struct i40e_ring { struct rcu_head rcu; /* to avoid race on free */ u16 next_to_alloc; - struct sk_buff *skb; /* When i40e_clean_rx_ring_irq() must - * return before it sees the EOP for - * the current packet, we save that skb - * here and resume receiving this - * packet the next time - * i40e_clean_rx_ring_irq() is called - * for this ring. - */ struct i40e_channel *ch; u16 rx_offset;