From 1b7bde6d659d30f171259cc2dfba8e5dab34e735 Mon Sep 17 00:00:00 2001 From: Nimrod Andy Date: Tue, 30 Sep 2014 09:28:05 +0800 Subject: [PATCH] net: fec: implement rx_copybreak to improve rx performance - Copy short frames and keep the buffers mapped, re-allocate skb instead of memory copy for long frames. - Add support for setting/getting rx_copybreak using generic ethtool tunable Changes V3: * As Eric Dumazet's suggestion that removing the copybreak module parameter and only keep the ethtool API support for rx_copybreak. Changes V2: * Implements rx_copybreak * Rx_copybreak provides module parameter to change this value * Add tunable_ops support for rx_copybreak Signed-off-by: Fugang Duan Signed-off-by: Frank Li Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fec.h | 2 + drivers/net/ethernet/freescale/fec_main.c | 208 ++++++++++++++++++++---------- 2 files changed, 145 insertions(+), 65 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h index 354a309..1d5e182 100644 --- a/drivers/net/ethernet/freescale/fec.h +++ b/drivers/net/ethernet/freescale/fec.h @@ -482,6 +482,8 @@ struct fec_enet_private { unsigned int tx_pkts_itr; unsigned int tx_time_itr; unsigned int itr_clk_rate; + + u32 rx_copybreak; }; void fec_ptp_init(struct platform_device *pdev); diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 2c73434..1f07db8 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -236,6 +236,8 @@ MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address"); #define FEC_PAUSE_FLAG_AUTONEG 0x1 #define FEC_PAUSE_FLAG_ENABLE 0x2 +#define COPYBREAK_DEFAULT 256 + #define TSO_HEADER_SIZE 128 /* Max number of allowed TCP segments for software TSO */ #define FEC_MAX_TSO_SEGS 100 @@ -1322,6 +1324,50 @@ fec_enet_tx(struct net_device *ndev) return; } +static int +fec_enet_new_rxbdp(struct net_device *ndev, struct bufdesc *bdp, struct sk_buff *skb) +{ + struct fec_enet_private *fep = netdev_priv(ndev); + int off; + + off = ((unsigned long)skb->data) & fep->rx_align; + if (off) + skb_reserve(skb, fep->rx_align + 1 - off); + + bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, skb->data, + FEC_ENET_RX_FRSIZE - fep->rx_align, + DMA_FROM_DEVICE); + if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) { + if (net_ratelimit()) + netdev_err(ndev, "Rx DMA memory map failed\n"); + return -ENOMEM; + } + + return 0; +} + +static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb, + struct bufdesc *bdp, u32 length) +{ + struct fec_enet_private *fep = netdev_priv(ndev); + struct sk_buff *new_skb; + + if (length > fep->rx_copybreak) + return false; + + new_skb = netdev_alloc_skb(ndev, length); + if (!new_skb) + return false; + + dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr, + FEC_ENET_RX_FRSIZE - fep->rx_align, + DMA_FROM_DEVICE); + memcpy(new_skb->data, (*skb)->data, length); + *skb = new_skb; + + return true; +} + /* During a receive, the cur_rx points to the current incoming buffer. * When we update through the ring, if the next incoming buffer has * not been given to the system, we just set the empty indicator, @@ -1336,7 +1382,8 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) struct fec_enet_priv_rx_q *rxq; struct bufdesc *bdp; unsigned short status; - struct sk_buff *skb; + struct sk_buff *skb_new = NULL; + struct sk_buff *skb; ushort pkt_len; __u8 *data; int pkt_received = 0; @@ -1344,6 +1391,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) bool vlan_packet_rcvd = false; u16 vlan_tag; int index = 0; + bool is_copybreak; #ifdef CONFIG_M532x flush_cache_all(); @@ -1401,11 +1449,27 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) ndev->stats.rx_bytes += pkt_len; index = fec_enet_get_bd_index(rxq->rx_bd_base, bdp, fep); - data = rxq->rx_skbuff[index]->data; - dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr, - FEC_ENET_RX_FRSIZE - fep->rx_align, - DMA_FROM_DEVICE); + skb = rxq->rx_skbuff[index]; + /* The packet length includes FCS, but we don't want to + * include that when passing upstream as it messes up + * bridging applications. + */ + is_copybreak = fec_enet_copybreak(ndev, &skb, bdp, pkt_len - 4); + if (!is_copybreak) { + skb_new = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE); + if (unlikely(!skb_new)) { + ndev->stats.rx_dropped++; + goto rx_processing_done; + } + dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr, + FEC_ENET_RX_FRSIZE - fep->rx_align, + DMA_FROM_DEVICE); + } + + prefetch(skb->data - NET_IP_ALIGN); + skb_put(skb, pkt_len - 4); + data = skb->data; if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME) swap_buffer(data, pkt_len); @@ -1422,62 +1486,48 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id) struct vlan_hdr *vlan_header = (struct vlan_hdr *) (data + ETH_HLEN); vlan_tag = ntohs(vlan_header->h_vlan_TCI); - pkt_len -= VLAN_HLEN; vlan_packet_rcvd = true; + + skb_copy_to_linear_data_offset(skb, VLAN_HLEN, + data, (2 * ETH_ALEN)); + skb_pull(skb, VLAN_HLEN); } - /* This does 16 byte alignment, exactly what we need. - * The packet length includes FCS, but we don't want to - * include that when passing upstream as it messes up - * bridging applications. - */ - skb = netdev_alloc_skb(ndev, pkt_len - 4 + NET_IP_ALIGN); + skb->protocol = eth_type_trans(skb, ndev); - if (unlikely(!skb)) { - ndev->stats.rx_dropped++; - } else { - int payload_offset = (2 * ETH_ALEN); - skb_reserve(skb, NET_IP_ALIGN); - skb_put(skb, pkt_len - 4); /* Make room */ - - /* Extract the frame data without the VLAN header. */ - skb_copy_to_linear_data(skb, data, (2 * ETH_ALEN)); - if (vlan_packet_rcvd) - payload_offset = (2 * ETH_ALEN) + VLAN_HLEN; - skb_copy_to_linear_data_offset(skb, (2 * ETH_ALEN), - data + payload_offset, - pkt_len - 4 - (2 * ETH_ALEN)); - - skb->protocol = eth_type_trans(skb, ndev); - - /* Get receive timestamp from the skb */ - if (fep->hwts_rx_en && fep->bufdesc_ex) - fec_enet_hwtstamp(fep, ebdp->ts, - skb_hwtstamps(skb)); - - if (fep->bufdesc_ex && - (fep->csum_flags & FLAG_RX_CSUM_ENABLED)) { - if (!(ebdp->cbd_esc & FLAG_RX_CSUM_ERROR)) { - /* don't check it */ - skb->ip_summed = CHECKSUM_UNNECESSARY; - } else { - skb_checksum_none_assert(skb); - } + /* Get receive timestamp from the skb */ + if (fep->hwts_rx_en && fep->bufdesc_ex) + fec_enet_hwtstamp(fep, ebdp->ts, + skb_hwtstamps(skb)); + + if (fep->bufdesc_ex && + (fep->csum_flags & FLAG_RX_CSUM_ENABLED)) { + if (!(ebdp->cbd_esc & FLAG_RX_CSUM_ERROR)) { + /* don't check it */ + skb->ip_summed = CHECKSUM_UNNECESSARY; + } else { + skb_checksum_none_assert(skb); } + } - /* Handle received VLAN packets */ - if (vlan_packet_rcvd) - __vlan_hwaccel_put_tag(skb, - htons(ETH_P_8021Q), - vlan_tag); + /* Handle received VLAN packets */ + if (vlan_packet_rcvd) + __vlan_hwaccel_put_tag(skb, + htons(ETH_P_8021Q), + vlan_tag); - napi_gro_receive(&fep->napi, skb); + napi_gro_receive(&fep->napi, skb); + + if (is_copybreak) { + dma_sync_single_for_device(&fep->pdev->dev, bdp->cbd_bufaddr, + FEC_ENET_RX_FRSIZE - fep->rx_align, + DMA_FROM_DEVICE); + } else { + rxq->rx_skbuff[index] = skb_new; + fec_enet_new_rxbdp(ndev, bdp, skb_new); } - dma_sync_single_for_device(&fep->pdev->dev, bdp->cbd_bufaddr, - FEC_ENET_RX_FRSIZE - fep->rx_align, - DMA_FROM_DEVICE); rx_processing_done: /* Clear the status flags for this buffer */ status &= ~BD_ENET_RX_STATS; @@ -2392,6 +2442,44 @@ static void fec_enet_itr_coal_init(struct net_device *ndev) fec_enet_set_coalesce(ndev, &ec); } +static int fec_enet_get_tunable(struct net_device *netdev, + const struct ethtool_tunable *tuna, + void *data) +{ + struct fec_enet_private *fep = netdev_priv(netdev); + int ret = 0; + + switch (tuna->id) { + case ETHTOOL_RX_COPYBREAK: + *(u32 *)data = fep->rx_copybreak; + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static int fec_enet_set_tunable(struct net_device *netdev, + const struct ethtool_tunable *tuna, + const void *data) +{ + struct fec_enet_private *fep = netdev_priv(netdev); + int ret = 0; + + switch (tuna->id) { + case ETHTOOL_RX_COPYBREAK: + fep->rx_copybreak = *(u32 *)data; + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + static const struct ethtool_ops fec_enet_ethtool_ops = { .get_settings = fec_enet_get_settings, .set_settings = fec_enet_set_settings, @@ -2408,6 +2496,8 @@ static const struct ethtool_ops fec_enet_ethtool_ops = { .get_sset_count = fec_enet_get_sset_count, #endif .get_ts_info = fec_enet_get_ts_info, + .get_tunable = fec_enet_get_tunable, + .set_tunable = fec_enet_set_tunable, }; static int fec_enet_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd) @@ -2553,33 +2643,20 @@ fec_enet_alloc_rxq_buffers(struct net_device *ndev, unsigned int queue) struct sk_buff *skb; struct bufdesc *bdp; struct fec_enet_priv_rx_q *rxq; - unsigned int off; rxq = fep->rx_queue[queue]; bdp = rxq->rx_bd_base; for (i = 0; i < rxq->rx_ring_size; i++) { - dma_addr_t addr; - skb = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE); if (!skb) goto err_alloc; - off = ((unsigned long)skb->data) & fep->rx_align; - if (off) - skb_reserve(skb, fep->rx_align + 1 - off); - - addr = dma_map_single(&fep->pdev->dev, skb->data, - FEC_ENET_RX_FRSIZE - fep->rx_align, DMA_FROM_DEVICE); - - if (dma_mapping_error(&fep->pdev->dev, addr)) { + if (fec_enet_new_rxbdp(ndev, bdp, skb)) { dev_kfree_skb(skb); - if (net_ratelimit()) - netdev_err(ndev, "Rx DMA memory map failed\n"); goto err_alloc; } rxq->rx_skbuff[i] = skb; - bdp->cbd_bufaddr = addr; bdp->cbd_sc = BD_ENET_RX_EMPTY; if (fep->bufdesc_ex) { @@ -3240,6 +3317,7 @@ fec_probe(struct platform_device *pdev) if (fep->bufdesc_ex && fep->ptp_clock) netdev_info(ndev, "registered PHC device %d\n", fep->dev_id); + fep->rx_copybreak = COPYBREAK_DEFAULT; INIT_WORK(&fep->tx_timeout_work, fec_enet_timeout_work); return 0; -- 2.7.4