From 22ad38381547950c64ab8590ebf04a5d3693cbb7 Mon Sep 17 00:00:00 2001 From: Giuseppe Cavallaro Date: Mon, 29 Feb 2016 14:27:41 +0100 Subject: [PATCH] stmmac: do not perform zero-copy for rx frames This patch is to allow this driver to copy tiny frames during the reception process. This is giving more stability while stressing the driver on STi embedded systems. Signed-off-by: Giuseppe Cavallaro Signed-off-by: Alexandre TORGUE Signed-off-by: David S. Miller --- drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 + .../ethernet/stmicro/stmmac/stmmac_ethtool.c | 39 ++++++++++++ .../net/ethernet/stmicro/stmmac/stmmac_main.c | 61 ++++++++++++++----- 3 files changed, 86 insertions(+), 15 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h index 0d01f3ea4cc8..221f5cda70f3 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h @@ -74,6 +74,7 @@ struct stmmac_priv { unsigned int cur_rx; unsigned int dirty_rx; unsigned int dma_buf_sz; + unsigned int rx_copybreak; u32 rx_riwt; int hwts_rx_en; dma_addr_t *rx_skbuff_dma; diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c index c803d4cfa044..3c7928edfebb 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c @@ -781,6 +781,43 @@ static int stmmac_get_ts_info(struct net_device *dev, return ethtool_op_get_ts_info(dev, info); } +static int stmmac_get_tunable(struct net_device *dev, + const struct ethtool_tunable *tuna, void *data) +{ + struct stmmac_priv *priv = netdev_priv(dev); + int ret = 0; + + switch (tuna->id) { + case ETHTOOL_RX_COPYBREAK: + *(u32 *)data = priv->rx_copybreak; + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static int stmmac_set_tunable(struct net_device *dev, + const struct ethtool_tunable *tuna, + const void *data) +{ + struct stmmac_priv *priv = netdev_priv(dev); + int ret = 0; + + switch (tuna->id) { + case ETHTOOL_RX_COPYBREAK: + priv->rx_copybreak = *(u32 *)data; + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + static const struct ethtool_ops stmmac_ethtool_ops = { .begin = stmmac_check_if_running, .get_drvinfo = stmmac_ethtool_getdrvinfo, @@ -803,6 +840,8 @@ static const struct ethtool_ops stmmac_ethtool_ops = { .get_ts_info = stmmac_get_ts_info, .get_coalesce = stmmac_get_coalesce, .set_coalesce = stmmac_set_coalesce, + .get_tunable = stmmac_get_tunable, + .set_tunable = stmmac_set_tunable, }; void stmmac_set_ethtool_ops(struct net_device *netdev) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 3cc135559a1d..2ffe8dd9ce99 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -91,6 +91,8 @@ static int buf_sz = DEFAULT_BUFSIZE; module_param(buf_sz, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(buf_sz, "DMA buffer size"); +#define STMMAC_RX_COPYBREAK 256 + static const u32 default_msg_level = (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK | NETIF_MSG_IFUP | NETIF_MSG_IFDOWN | NETIF_MSG_TIMER); @@ -1808,6 +1810,7 @@ static int stmmac_open(struct net_device *dev) priv->xstats.threshold = tc; priv->dma_buf_sz = STMMAC_ALIGN(buf_sz); + priv->rx_copybreak = STMMAC_RX_COPYBREAK; ret = alloc_dma_desc_resources(priv); if (ret < 0) { @@ -2159,8 +2162,7 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv) struct sk_buff *skb; skb = netdev_alloc_skb_ip_align(priv->dev, bfsize); - - if (unlikely(skb == NULL)) + if (unlikely(!skb)) break; priv->rx_skbuff[entry] = skb; @@ -2282,23 +2284,52 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit) pr_debug("\tframe size %d, COE: %d\n", frame_len, status); } - skb = priv->rx_skbuff[entry]; - if (unlikely(!skb)) { - pr_err("%s: Inconsistent Rx descriptor chain\n", - priv->dev->name); - priv->dev->stats.rx_dropped++; - break; + + if (unlikely(frame_len < priv->rx_copybreak)) { + skb = netdev_alloc_skb_ip_align(priv->dev, + frame_len); + if (unlikely(!skb)) { + if (net_ratelimit()) + dev_warn(priv->device, + "packet dropped\n"); + priv->dev->stats.rx_dropped++; + break; + } + + dma_sync_single_for_cpu(priv->device, + priv->rx_skbuff_dma + [entry], frame_len, + DMA_FROM_DEVICE); + skb_copy_to_linear_data(skb, + priv-> + rx_skbuff[entry]->data, + frame_len); + + skb_put(skb, frame_len); + dma_sync_single_for_device(priv->device, + priv->rx_skbuff_dma + [entry], frame_len, + DMA_FROM_DEVICE); + } else { + skb = priv->rx_skbuff[entry]; + if (unlikely(!skb)) { + pr_err("%s: Inconsistent Rx chain\n", + priv->dev->name); + priv->dev->stats.rx_dropped++; + break; + } + prefetch(skb->data - NET_IP_ALIGN); + priv->rx_skbuff[entry] = NULL; + + skb_put(skb, frame_len); + dma_unmap_single(priv->device, + priv->rx_skbuff_dma[entry], + priv->dma_buf_sz, + DMA_FROM_DEVICE); } - prefetch(skb->data - NET_IP_ALIGN); - priv->rx_skbuff[entry] = NULL; stmmac_get_rx_hwtstamp(priv, entry, skb); - skb_put(skb, frame_len); - dma_unmap_single(priv->device, - priv->rx_skbuff_dma[entry], - priv->dma_buf_sz, DMA_FROM_DEVICE); - if (netif_msg_pktdata(priv)) { pr_debug("frame received (%dbytes)", frame_len); print_pkt(skb->data, frame_len); -- 2.30.2