Add support for receiving network frames that span multiple DMA descriptors in the Cadence MACB/GEM Ethernet driver. The patch removes the requirement that limited frame reception to a single descriptor (RX_SOF && RX_EOF), also avoiding potential contiguous multi-page allocation for large frames. It also uses page pool fragments allocation instead of full page for saving memory. Signed-off-by: Paolo Valerio --- drivers/net/ethernet/cadence/macb.h | 4 +- drivers/net/ethernet/cadence/macb_main.c | 180 ++++++++++++++--------- 2 files changed, 111 insertions(+), 73 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h index dcf768bd1bc1..e2f397b7a27f 100644 --- a/drivers/net/ethernet/cadence/macb.h +++ b/drivers/net/ethernet/cadence/macb.h @@ -960,8 +960,7 @@ struct macb_dma_desc_ptp { #define PPM_FRACTION 16 /* The buf includes headroom compatible with both skb and xdpf */ -#define MACB_PP_HEADROOM XDP_PACKET_HEADROOM -#define MACB_PP_MAX_BUF_SIZE(num) (((num) * PAGE_SIZE) - MACB_PP_HEADROOM) +#define MACB_PP_HEADROOM XDP_PACKET_HEADROOM /* struct macb_tx_skb - data about an skb which is being transmitted * @skb: skb currently being transmitted, only set for the last buffer @@ -1273,6 +1272,7 @@ struct macb_queue { struct napi_struct napi_rx; struct queue_stats stats; struct page_pool *page_pool; + struct sk_buff *skb; }; struct ethtool_rx_fs_item { diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 985c81913ba6..be0c8e101639 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -1250,21 +1250,25 @@ static int macb_tx_complete(struct macb_queue *queue, int budget) return packets; } -static void *gem_page_pool_get_buff(struct page_pool *pool, +static void *gem_page_pool_get_buff(struct macb_queue *queue, dma_addr_t *dma_addr, gfp_t gfp_mask) { + struct macb *bp = queue->bp; struct page *page; + int offset; - if (!pool) + if (!queue->page_pool) return NULL; - page = page_pool_alloc_pages(pool, gfp_mask | __GFP_NOWARN); + page = page_pool_alloc_frag(queue->page_pool, &offset, + bp->rx_buffer_size, + gfp_mask | __GFP_NOWARN); if (!page) return NULL; - *dma_addr = page_pool_get_dma_addr(page) + MACB_PP_HEADROOM; + *dma_addr = page_pool_get_dma_addr(page) + MACB_PP_HEADROOM + offset; - return page_address(page); + return page_address(page) + offset; } static void gem_rx_refill(struct macb_queue *queue, bool napi) @@ -1286,7 +1290,7 @@ static void gem_rx_refill(struct macb_queue *queue, bool napi) if (!queue->rx_buff[entry]) { /* allocate sk_buff for this free entry in ring */ - data = gem_page_pool_get_buff(queue->page_pool, &paddr, + data = gem_page_pool_get_buff(queue, &paddr, napi ? GFP_ATOMIC : GFP_KERNEL); if (unlikely(!data)) { netdev_err(bp->dev, @@ -1344,20 +1348,17 @@ static int gem_rx(struct macb_queue *queue, struct napi_struct *napi, int budget) { struct macb *bp = queue->bp; - int buffer_size; unsigned int len; unsigned int entry; void *data; - struct sk_buff *skb; struct macb_dma_desc *desc; + int data_len; int count = 0; - buffer_size = DIV_ROUND_UP(bp->rx_buffer_size, PAGE_SIZE) * PAGE_SIZE; - while (count < budget) { u32 ctrl; dma_addr_t addr; - bool rxused; + bool rxused, first_frame; entry = macb_rx_ring_wrap(bp, queue->rx_tail); desc = macb_rx_desc(queue, entry); @@ -1368,6 +1369,9 @@ static int gem_rx(struct macb_queue *queue, struct napi_struct *napi, rxused = (desc->addr & MACB_BIT(RX_USED)) ? true : false; addr = macb_get_addr(bp, desc); + dma_sync_single_for_cpu(&bp->pdev->dev, + addr, bp->rx_buffer_size - bp->rx_offset, + page_pool_get_dma_dir(queue->page_pool)); if (!rxused) break; @@ -1379,13 +1383,6 @@ static int gem_rx(struct macb_queue *queue, struct napi_struct *napi, queue->rx_tail++; count++; - if (!(ctrl & MACB_BIT(RX_SOF) && ctrl & MACB_BIT(RX_EOF))) { - netdev_err(bp->dev, - "not whole frame pointed by descriptor\n"); - bp->dev->stats.rx_dropped++; - queue->stats.rx_dropped++; - break; - } data = queue->rx_buff[entry]; if (unlikely(!data)) { netdev_err(bp->dev, @@ -1395,64 +1392,102 @@ static int gem_rx(struct macb_queue *queue, struct napi_struct *napi, break; } - skb = napi_build_skb(data, buffer_size); - if (unlikely(!skb)) { - netdev_err(bp->dev, - "Unable to allocate sk_buff\n"); - page_pool_put_full_page(queue->page_pool, - virt_to_head_page(data), - false); - break; + first_frame = ctrl & MACB_BIT(RX_SOF); + len = ctrl & bp->rx_frm_len_mask; + + if (len) { + data_len = len; + if (!first_frame) + data_len -= queue->skb->len; + } else { + data_len = SKB_WITH_OVERHEAD(bp->rx_buffer_size) - bp->rx_offset; } - /* Properly align Ethernet header. - * - * Hardware can add dummy bytes if asked using the RBOF - * field inside the NCFGR register. That feature isn't - * available if hardware is RSC capable. - * - * We cannot fallback to doing the 2-byte shift before - * DMA mapping because the address field does not allow - * setting the low 2/3 bits. - * It is 3 bits if HW_DMA_CAP_PTP, else 2 bits. - */ - skb_reserve(skb, bp->rx_offset); - skb_mark_for_recycle(skb); + if (first_frame) { + queue->skb = napi_build_skb(data, bp->rx_buffer_size); + if (unlikely(!queue->skb)) { + netdev_err(bp->dev, + "Unable to allocate sk_buff\n"); + goto free_frags; + } + + /* Properly align Ethernet header. + * + * Hardware can add dummy bytes if asked using the RBOF + * field inside the NCFGR register. That feature isn't + * available if hardware is RSC capable. + * + * We cannot fallback to doing the 2-byte shift before + * DMA mapping because the address field does not allow + * setting the low 2/3 bits. + * It is 3 bits if HW_DMA_CAP_PTP, else 2 bits. + */ + skb_reserve(queue->skb, bp->rx_offset); + skb_mark_for_recycle(queue->skb); + skb_put(queue->skb, data_len); + queue->skb->protocol = eth_type_trans(queue->skb, bp->dev); + + skb_checksum_none_assert(queue->skb); + if (bp->dev->features & NETIF_F_RXCSUM && + !(bp->dev->flags & IFF_PROMISC) && + GEM_BFEXT(RX_CSUM, ctrl) & GEM_RX_CSUM_CHECKED_MASK) + queue->skb->ip_summed = CHECKSUM_UNNECESSARY; + } else { + if (!queue->skb) { + netdev_err(bp->dev, + "Received non-starting frame while expecting it\n"); + goto free_frags; + } + + struct skb_shared_info *shinfo = skb_shinfo(queue->skb); + struct page *page = virt_to_head_page(data); + int nr_frags = shinfo->nr_frags; + + if (nr_frags >= ARRAY_SIZE(shinfo->frags)) + goto free_frags; + + skb_add_rx_frag(queue->skb, nr_frags, page, + data - page_address(page) + bp->rx_offset, + data_len, bp->rx_buffer_size); + } /* now everything is ready for receiving packet */ queue->rx_buff[entry] = NULL; - len = ctrl & bp->rx_frm_len_mask; - - netdev_vdbg(bp->dev, "gem_rx %u (len %u)\n", entry, len); - dma_sync_single_for_cpu(&bp->pdev->dev, - addr, len, - page_pool_get_dma_dir(queue->page_pool)); - skb_put(skb, len); - skb->protocol = eth_type_trans(skb, bp->dev); - skb_checksum_none_assert(skb); - if (bp->dev->features & NETIF_F_RXCSUM && - !(bp->dev->flags & IFF_PROMISC) && - GEM_BFEXT(RX_CSUM, ctrl) & GEM_RX_CSUM_CHECKED_MASK) - skb->ip_summed = CHECKSUM_UNNECESSARY; + netdev_vdbg(bp->dev, "%s %u (len %u)\n", __func__, entry, data_len); - bp->dev->stats.rx_packets++; - queue->stats.rx_packets++; - bp->dev->stats.rx_bytes += skb->len; - queue->stats.rx_bytes += skb->len; + if (ctrl & MACB_BIT(RX_EOF)) { + bp->dev->stats.rx_packets++; + queue->stats.rx_packets++; + bp->dev->stats.rx_bytes += queue->skb->len; + queue->stats.rx_bytes += queue->skb->len; - gem_ptp_do_rxstamp(bp, skb, desc); + gem_ptp_do_rxstamp(bp, queue->skb, desc); #if defined(DEBUG) && defined(VERBOSE_DEBUG) - netdev_vdbg(bp->dev, "received skb of length %u, csum: %08x\n", - skb->len, skb->csum); - print_hex_dump(KERN_DEBUG, " mac: ", DUMP_PREFIX_ADDRESS, 16, 1, - skb_mac_header(skb), 16, true); - print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_ADDRESS, 16, 1, - skb->data, 32, true); + netdev_vdbg(bp->dev, "received skb of length %u, csum: %08x\n", + queue->skb->len, queue->skb->csum); + print_hex_dump(KERN_DEBUG, " mac: ", DUMP_PREFIX_ADDRESS, 16, 1, + skb_mac_header(queue->skb), 16, true); + print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_ADDRESS, 16, 1, + queue->skb->data, 32, true); #endif - napi_gro_receive(napi, skb); + napi_gro_receive(napi, queue->skb); + queue->skb = NULL; + } + + continue; + +free_frags: + if (queue->skb) { + dev_kfree_skb(queue->skb); + queue->skb = NULL; + } else { + page_pool_put_full_page(queue->page_pool, + virt_to_head_page(data), + false); + } } gem_rx_refill(queue, true); @@ -2394,7 +2429,10 @@ static void macb_init_rx_buffer_size(struct macb *bp, size_t size) if (!macb_is_gem(bp)) { bp->rx_buffer_size = MACB_RX_BUFFER_SIZE; } else { - bp->rx_buffer_size = size; + bp->rx_buffer_size = size + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) + + MACB_PP_HEADROOM; + if (bp->rx_buffer_size > PAGE_SIZE) + bp->rx_buffer_size = PAGE_SIZE; if (bp->rx_buffer_size % RX_BUFFER_MULTIPLE) { netdev_dbg(bp->dev, @@ -2589,18 +2627,15 @@ static int macb_alloc_consistent(struct macb *bp) static void gem_create_page_pool(struct macb_queue *queue) { - unsigned int num_pages = DIV_ROUND_UP(queue->bp->rx_buffer_size, PAGE_SIZE); - struct macb *bp = queue->bp; struct page_pool_params pp_params = { - .order = order_base_2(num_pages), + .order = 0, .flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV, .pool_size = queue->bp->rx_ring_size, .nid = NUMA_NO_NODE, .dma_dir = DMA_FROM_DEVICE, .dev = &queue->bp->pdev->dev, .napi = &queue->napi_rx, - .offset = bp->rx_offset, - .max_len = MACB_PP_MAX_BUF_SIZE(num_pages), + .max_len = PAGE_SIZE, }; struct page_pool *pool; @@ -2784,8 +2819,9 @@ static void macb_configure_dma(struct macb *bp) unsigned int q; u32 dmacfg; - buffer_size = bp->rx_buffer_size / RX_BUFFER_MULTIPLE; if (macb_is_gem(bp)) { + buffer_size = SKB_WITH_OVERHEAD(bp->rx_buffer_size) - bp->rx_offset; + buffer_size /= RX_BUFFER_MULTIPLE; dmacfg = gem_readl(bp, DMACFG) & ~GEM_BF(RXBS, -1L); for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) { if (q) @@ -2816,6 +2852,8 @@ static void macb_configure_dma(struct macb *bp) netdev_dbg(bp->dev, "Cadence configure DMA with 0x%08x\n", dmacfg); gem_writel(bp, DMACFG, dmacfg); + } else { + buffer_size = bp->rx_buffer_size / RX_BUFFER_MULTIPLE; } } -- 2.51.1