From: Alexander Duyck Date: Sat, 2 Feb 2013 05:07:11 +0000 (+0000) Subject: igb: Support using build_skb in the case that jumbo frames are disabled X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=74e238eada573540f82530f8ae4f3343c023d774;p=linux-beck.git igb: Support using build_skb in the case that jumbo frames are disabled This change makes it so that we can enable the use of build_skb for cases where jumbo frames are disabled. The advantage to this is that we do not have to perform a memcpy to populate the header and as a result we see a significant performance improvement. Signed-off-by: Alexander Duyck Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h index 4b78053592ba..afdb8bbcf6ce 100644 --- a/drivers/net/ethernet/intel/igb/igb.h +++ b/drivers/net/ethernet/intel/igb/igb.h @@ -275,10 +275,18 @@ struct igb_q_vector { enum e1000_ring_flags_t { IGB_RING_FLAG_RX_SCTP_CSUM, IGB_RING_FLAG_RX_LB_VLAN_BSWAP, + IGB_RING_FLAG_RX_BUILD_SKB_ENABLED, IGB_RING_FLAG_TX_CTX_IDX, IGB_RING_FLAG_TX_DETECT_HANG }; +#define ring_uses_build_skb(ring) \ + test_bit(IGB_RING_FLAG_RX_BUILD_SKB_ENABLED, &(ring)->flags) +#define set_ring_build_skb_enabled(ring) \ + set_bit(IGB_RING_FLAG_RX_BUILD_SKB_ENABLED, &(ring)->flags) +#define clear_ring_build_skb_enabled(ring) \ + clear_bit(IGB_RING_FLAG_RX_BUILD_SKB_ENABLED, &(ring)->flags) + #define IGB_TXD_DCMD (E1000_ADVTXD_DCMD_EOP | E1000_ADVTXD_DCMD_RS) #define IGB_RX_DESC(R, i) \ diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 1aaf19351863..b070a97376c8 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -3354,6 +3354,20 @@ void igb_configure_rx_ring(struct igb_adapter *adapter, wr32(E1000_RXDCTL(reg_idx), rxdctl); } +static void igb_set_rx_buffer_len(struct igb_adapter *adapter, + struct igb_ring *rx_ring) +{ +#define IGB_MAX_BUILD_SKB_SIZE \ + (SKB_WITH_OVERHEAD(IGB_RX_BUFSZ) - \ + (NET_SKB_PAD + NET_IP_ALIGN + IGB_TS_HDR_LEN)) + + /* set build_skb flag */ + if (adapter->max_frame_size <= IGB_MAX_BUILD_SKB_SIZE) + set_ring_build_skb_enabled(rx_ring); + else + clear_ring_build_skb_enabled(rx_ring); +} + /** * igb_configure_rx - Configure receive Unit after Reset * @adapter: board private structure @@ -3373,8 +3387,11 @@ static void igb_configure_rx(struct igb_adapter *adapter) /* Setup the HW Rx Head and Tail Descriptor Pointers and * the Base and Length of the Rx Descriptor Ring */ - for (i = 0; i < adapter->num_rx_queues; i++) - igb_configure_rx_ring(adapter, adapter->rx_ring[i]); + for (i = 0; i < adapter->num_rx_queues; i++) { + struct igb_ring *rx_ring = adapter->rx_ring[i]; + igb_set_rx_buffer_len(adapter, rx_ring); + igb_configure_rx_ring(adapter, rx_ring); + } } /** @@ -6097,6 +6114,41 @@ static void igb_reuse_rx_page(struct igb_ring *rx_ring, DMA_FROM_DEVICE); } +static bool igb_can_reuse_rx_page(struct igb_rx_buffer *rx_buffer, + struct page *page, + unsigned int truesize) +{ + /* avoid re-using remote pages */ + if (unlikely(page_to_nid(page) != numa_node_id())) + return false; + +#if (PAGE_SIZE < 8192) + /* if we are only owner of page we can reuse it */ + if (unlikely(page_count(page) != 1)) + return false; + + /* flip page offset to other buffer */ + rx_buffer->page_offset ^= IGB_RX_BUFSZ; + + /* since we are the only owner of the page and we need to + * increment it, just set the value to 2 in order to avoid + * an unnecessary locked operation + */ + atomic_set(&page->_count, 2); +#else + /* move offset up to the next cache line */ + rx_buffer->page_offset += truesize; + + if (rx_buffer->page_offset > (PAGE_SIZE - IGB_RX_BUFSZ)) + return false; + + /* bump ref count on page before it is given to the stack */ + get_page(page); +#endif + + return true; +} + /** * igb_add_rx_frag - Add contents of Rx buffer to sk_buff * @rx_ring: rx descriptor ring to transact packets on @@ -6119,6 +6171,11 @@ static bool igb_add_rx_frag(struct igb_ring *rx_ring, { struct page *page = rx_buffer->page; unsigned int size = le16_to_cpu(rx_desc->wb.upper.length); +#if (PAGE_SIZE < 8192) + unsigned int truesize = IGB_RX_BUFSZ; +#else + unsigned int truesize = ALIGN(size, L1_CACHE_BYTES); +#endif if ((size <= IGB_RX_HDR_LEN) && !skb_is_nonlinear(skb)) { unsigned char *va = page_address(page) + rx_buffer->page_offset; @@ -6141,38 +6198,88 @@ static bool igb_add_rx_frag(struct igb_ring *rx_ring, } skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, - rx_buffer->page_offset, size, IGB_RX_BUFSZ); + rx_buffer->page_offset, size, truesize); - /* avoid re-using remote pages */ - if (unlikely(page_to_nid(page) != numa_node_id())) - return false; + return igb_can_reuse_rx_page(rx_buffer, page, truesize); +} +static struct sk_buff *igb_build_rx_buffer(struct igb_ring *rx_ring, + union e1000_adv_rx_desc *rx_desc) +{ + struct igb_rx_buffer *rx_buffer; + struct sk_buff *skb; + struct page *page; + void *page_addr; + unsigned int size = le16_to_cpu(rx_desc->wb.upper.length); #if (PAGE_SIZE < 8192) - /* if we are only owner of page we can reuse it */ - if (unlikely(page_count(page) != 1)) - return false; + unsigned int truesize = IGB_RX_BUFSZ; +#else + unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) + + SKB_DATA_ALIGN(NET_SKB_PAD + + NET_IP_ALIGN + + size); +#endif - /* flip page offset to other buffer */ - rx_buffer->page_offset ^= IGB_RX_BUFSZ; + /* If we spanned a buffer we have a huge mess so test for it */ + BUG_ON(unlikely(!igb_test_staterr(rx_desc, E1000_RXD_STAT_EOP))); - /* - * since we are the only owner of the page and we need to - * increment it, just set the value to 2 in order to avoid - * an unnecessary locked operation - */ - atomic_set(&page->_count, 2); -#else - /* move offset up to the next cache line */ - rx_buffer->page_offset += SKB_DATA_ALIGN(size); + /* Guarantee this function can be used by verifying buffer sizes */ + BUILD_BUG_ON(SKB_WITH_OVERHEAD(IGB_RX_BUFSZ) < (NET_SKB_PAD + + NET_IP_ALIGN + + IGB_TS_HDR_LEN + + ETH_FRAME_LEN + + ETH_FCS_LEN)); - if (rx_buffer->page_offset > (PAGE_SIZE - IGB_RX_BUFSZ)) - return false; + rx_buffer = &rx_ring->rx_buffer_info[rx_ring->next_to_clean]; + page = rx_buffer->page; + prefetchw(page); - /* bump ref count on page before it is given to the stack */ - get_page(page); + page_addr = page_address(page) + rx_buffer->page_offset; + + /* prefetch first cache line of first page */ + prefetch(page_addr + NET_SKB_PAD + NET_IP_ALIGN); +#if L1_CACHE_BYTES < 128 + prefetch(page_addr + L1_CACHE_BYTES + NET_SKB_PAD + NET_IP_ALIGN); #endif - return true; + /* build an skb to around the page buffer */ + skb = build_skb(page_addr, truesize); + if (unlikely(!skb)) { + rx_ring->rx_stats.alloc_failed++; + return NULL; + } + + /* we are reusing so sync this buffer for CPU use */ + dma_sync_single_range_for_cpu(rx_ring->dev, + rx_buffer->dma, + rx_buffer->page_offset, + IGB_RX_BUFSZ, + DMA_FROM_DEVICE); + + /* update pointers within the skb to store the data */ + skb_reserve(skb, NET_IP_ALIGN + NET_SKB_PAD); + __skb_put(skb, size); + + /* pull timestamp out of packet data */ + if (igb_test_staterr(rx_desc, E1000_RXDADV_STAT_TSIP)) { + igb_ptp_rx_pktstamp(rx_ring->q_vector, skb->data, skb); + __skb_pull(skb, IGB_TS_HDR_LEN); + } + + if (igb_can_reuse_rx_page(rx_buffer, page, truesize)) { + /* hand second half of page back to the ring */ + igb_reuse_rx_page(rx_ring, rx_buffer); + } else { + /* we are not reusing the buffer so unmap it */ + dma_unmap_page(rx_ring->dev, rx_buffer->dma, + PAGE_SIZE, DMA_FROM_DEVICE); + } + + /* clear contents of buffer_info */ + rx_buffer->dma = 0; + rx_buffer->page = NULL; + + return skb; } static struct sk_buff *igb_fetch_rx_buffer(struct igb_ring *rx_ring, @@ -6184,13 +6291,6 @@ static struct sk_buff *igb_fetch_rx_buffer(struct igb_ring *rx_ring, rx_buffer = &rx_ring->rx_buffer_info[rx_ring->next_to_clean]; - /* - * This memory barrier is needed to keep us from reading - * any other fields out of the rx_desc until we know the - * RXD_STAT_DD bit is set - */ - rmb(); - page = rx_buffer->page; prefetchw(page); @@ -6590,8 +6690,17 @@ static bool igb_clean_rx_irq(struct igb_q_vector *q_vector, const int budget) if (!igb_test_staterr(rx_desc, E1000_RXD_STAT_DD)) break; + /* This memory barrier is needed to keep us from reading + * any other fields out of the rx_desc until we know the + * RXD_STAT_DD bit is set + */ + rmb(); + /* retrieve a buffer from the ring */ - skb = igb_fetch_rx_buffer(rx_ring, rx_desc, skb); + if (ring_uses_build_skb(rx_ring)) + skb = igb_build_rx_buffer(rx_ring, rx_desc); + else + skb = igb_fetch_rx_buffer(rx_ring, rx_desc, skb); /* exit if we failed to retrieve a buffer */ if (!skb) @@ -6678,6 +6787,14 @@ static bool igb_alloc_mapped_page(struct igb_ring *rx_ring, return true; } +static inline unsigned int igb_rx_offset(struct igb_ring *rx_ring) +{ + if (ring_uses_build_skb(rx_ring)) + return NET_SKB_PAD + NET_IP_ALIGN; + else + return 0; +} + /** * igb_alloc_rx_buffers - Replace used receive buffers; packet split * @adapter: address of board private structure @@ -6704,7 +6821,9 @@ void igb_alloc_rx_buffers(struct igb_ring *rx_ring, u16 cleaned_count) * Refresh the desc even if buffer_addrs didn't change * because each write-back erases this info. */ - rx_desc->read.pkt_addr = cpu_to_le64(bi->dma + bi->page_offset); + rx_desc->read.pkt_addr = cpu_to_le64(bi->dma + + bi->page_offset + + igb_rx_offset(rx_ring)); rx_desc++; bi++;