From baf387a8edaa4a55afeaf4f498d3891ddcb03fb7 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Thu, 28 May 2015 15:24:42 -0700 Subject: [PATCH 1/3] net: systemport: Pre-calculate and utilize cb->bd_addr There is a 1:1 mapping between the software maintained control block in priv->rx_cbs and the buffer address in priv->rx_bds, such that there is no need to keep computing the buffer address when refiling a control block. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bcmsysport.c | 18 +++++++++--------- drivers/net/ethernet/broadcom/bcmsysport.h | 2 -- 2 files changed, 9 insertions(+), 11 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index 084a50a555de..267330ccd595 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -549,12 +549,7 @@ static int bcm_sysport_rx_refill(struct bcm_sysport_priv *priv, } dma_unmap_addr_set(cb, dma_addr, mapping); - dma_desc_set_addr(priv, priv->rx_bd_assign_ptr, mapping); - - priv->rx_bd_assign_index++; - priv->rx_bd_assign_index &= (priv->num_rx_bds - 1); - priv->rx_bd_assign_ptr = priv->rx_bds + - (priv->rx_bd_assign_index * DESC_SIZE); + dma_desc_set_addr(priv, cb->bd_addr, mapping); netif_dbg(priv, rx_status, ndev, "RX refill\n"); @@ -568,7 +563,7 @@ static int bcm_sysport_alloc_rx_bufs(struct bcm_sysport_priv *priv) unsigned int i; for (i = 0; i < priv->num_rx_bds; i++) { - cb = &priv->rx_cbs[priv->rx_bd_assign_index]; + cb = &priv->rx_cbs[i]; if (cb->skb) continue; @@ -1330,14 +1325,14 @@ static inline int tdma_enable_set(struct bcm_sysport_priv *priv, static int bcm_sysport_init_rx_ring(struct bcm_sysport_priv *priv) { + struct bcm_sysport_cb *cb; u32 reg; int ret; + int i; /* Initialize SW view of the RX ring */ priv->num_rx_bds = NUM_RX_DESC; priv->rx_bds = priv->base + SYS_PORT_RDMA_OFFSET; - priv->rx_bd_assign_ptr = priv->rx_bds; - priv->rx_bd_assign_index = 0; priv->rx_c_index = 0; priv->rx_read_ptr = 0; priv->rx_cbs = kcalloc(priv->num_rx_bds, sizeof(struct bcm_sysport_cb), @@ -1347,6 +1342,11 @@ static int bcm_sysport_init_rx_ring(struct bcm_sysport_priv *priv) return -ENOMEM; } + for (i = 0; i < priv->num_rx_bds; i++) { + cb = priv->rx_cbs + i; + cb->bd_addr = priv->rx_bds + i * DESC_SIZE; + } + ret = bcm_sysport_alloc_rx_bufs(priv); if (ret) { netif_err(priv, hw, priv->netdev, "SKB allocation failed\n"); diff --git a/drivers/net/ethernet/broadcom/bcmsysport.h b/drivers/net/ethernet/broadcom/bcmsysport.h index 42a4b4a0bc14..f28bf545d7f4 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.h +++ b/drivers/net/ethernet/broadcom/bcmsysport.h @@ -663,8 +663,6 @@ struct bcm_sysport_priv { /* Receive queue */ void __iomem *rx_bds; - void __iomem *rx_bd_assign_ptr; - unsigned int rx_bd_assign_index; struct bcm_sysport_cb *rx_cbs; unsigned int num_rx_bds; unsigned int rx_read_ptr; From c73b01837eeeba91b9c22c67c6372a6b73f08473 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Thu, 28 May 2015 15:24:43 -0700 Subject: [PATCH 2/3] net: systemport: rewrite bcm_sysport_rx_refill Currently, bcm_sysport_desc_rx() calls bcm_sysport_rx_refill() at the end of Rx packet processing loop, after the current Rx packet has already been passed to napi_gro_receive(). However, bcm_sysport_rx_refill() might fail to allocate a new Rx skb, thus leaving a hole on the Rx queue where no valid Rx buffer exists. To eliminate this situation: 1. Rewrite bcm_sysport_rx_refill() to retain the current Rx skb on the Rx queue if a new replacement Rx skb can't be allocated and DMA-mapped. In this case, the data on the current Rx skb is effectively dropped. 2. Modify bcm_sysport_desc_rx() to call bcm_sysport_rx_refill() at the top of Rx packet processing loop, so that the new replacement Rx skb is already in place before the current Rx skb is processed. This is loosely inspired from d6707bec5986 ("net: bcmgenet: rewrite bcmgenet_rx_refill()") Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bcmsysport.c | 81 +++++++++++----------- 1 file changed, 41 insertions(+), 40 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index 267330ccd595..d777b0db9e63 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -524,62 +524,70 @@ static void bcm_sysport_free_cb(struct bcm_sysport_cb *cb) dma_unmap_addr_set(cb, dma_addr, 0); } -static int bcm_sysport_rx_refill(struct bcm_sysport_priv *priv, - struct bcm_sysport_cb *cb) +static struct sk_buff *bcm_sysport_rx_refill(struct bcm_sysport_priv *priv, + struct bcm_sysport_cb *cb) { struct device *kdev = &priv->pdev->dev; struct net_device *ndev = priv->netdev; + struct sk_buff *skb, *rx_skb; dma_addr_t mapping; - int ret; - cb->skb = netdev_alloc_skb(priv->netdev, RX_BUF_LENGTH); - if (!cb->skb) { + /* Allocate a new SKB for a new packet */ + skb = netdev_alloc_skb(priv->netdev, RX_BUF_LENGTH); + if (!skb) { + priv->mib.alloc_rx_buff_failed++; netif_err(priv, rx_err, ndev, "SKB alloc failed\n"); - return -ENOMEM; + return NULL; } - mapping = dma_map_single(kdev, cb->skb->data, + mapping = dma_map_single(kdev, skb->data, RX_BUF_LENGTH, DMA_FROM_DEVICE); - ret = dma_mapping_error(kdev, mapping); - if (ret) { + if (dma_mapping_error(kdev, mapping)) { priv->mib.rx_dma_failed++; - bcm_sysport_free_cb(cb); + dev_kfree_skb_any(skb); netif_err(priv, rx_err, ndev, "DMA mapping failure\n"); - return ret; + return NULL; } + /* Grab the current SKB on the ring */ + rx_skb = cb->skb; + if (likely(rx_skb)) + dma_unmap_single(kdev, dma_unmap_addr(cb, dma_addr), + RX_BUF_LENGTH, DMA_FROM_DEVICE); + + /* Put the new SKB on the ring */ + cb->skb = skb; dma_unmap_addr_set(cb, dma_addr, mapping); dma_desc_set_addr(priv, cb->bd_addr, mapping); netif_dbg(priv, rx_status, ndev, "RX refill\n"); - return 0; + /* Return the current SKB to the caller */ + return rx_skb; } static int bcm_sysport_alloc_rx_bufs(struct bcm_sysport_priv *priv) { struct bcm_sysport_cb *cb; - int ret = 0; + struct sk_buff *skb; unsigned int i; for (i = 0; i < priv->num_rx_bds; i++) { cb = &priv->rx_cbs[i]; - if (cb->skb) - continue; - - ret = bcm_sysport_rx_refill(priv, cb); - if (ret) - break; + skb = bcm_sysport_rx_refill(priv, cb); + if (skb) + dev_kfree_skb(skb); + if (!cb->skb) + return -ENOMEM; } - return ret; + return 0; } /* Poll the hardware for up to budget packets to process */ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv, unsigned int budget) { - struct device *kdev = &priv->pdev->dev; struct net_device *ndev = priv->netdev; unsigned int processed = 0, to_process; struct bcm_sysport_cb *cb; @@ -587,7 +595,6 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv, unsigned int p_index; u16 len, status; struct bcm_rsb *rsb; - int ret; /* Determine how much we should process since last call */ p_index = rdma_readl(priv, RDMA_PROD_INDEX); @@ -605,13 +612,8 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv, while ((processed < to_process) && (processed < budget)) { cb = &priv->rx_cbs[priv->rx_read_ptr]; - skb = cb->skb; + skb = bcm_sysport_rx_refill(priv, cb); - processed++; - priv->rx_read_ptr++; - - if (priv->rx_read_ptr == priv->num_rx_bds) - priv->rx_read_ptr = 0; /* We do not have a backing SKB, so we do not a corresponding * DMA mapping for this incoming packet since @@ -622,12 +624,9 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv, netif_err(priv, rx_err, ndev, "out of memory!\n"); ndev->stats.rx_dropped++; ndev->stats.rx_errors++; - goto refill; + goto next; } - dma_unmap_single(kdev, dma_unmap_addr(cb, dma_addr), - RX_BUF_LENGTH, DMA_FROM_DEVICE); - /* Extract the Receive Status Block prepended */ rsb = (struct bcm_rsb *)skb->data; len = (rsb->rx_status_len >> DESC_LEN_SHIFT) & DESC_LEN_MASK; @@ -643,8 +642,8 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv, netif_err(priv, rx_status, ndev, "fragmented packet!\n"); ndev->stats.rx_dropped++; ndev->stats.rx_errors++; - bcm_sysport_free_cb(cb); - goto refill; + dev_kfree_skb_any(skb); + goto next; } if (unlikely(status & (RX_STATUS_ERR | RX_STATUS_OVFLOW))) { @@ -653,8 +652,8 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv, ndev->stats.rx_over_errors++; ndev->stats.rx_dropped++; ndev->stats.rx_errors++; - bcm_sysport_free_cb(cb); - goto refill; + dev_kfree_skb_any(skb); + goto next; } skb_put(skb, len); @@ -681,10 +680,12 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv, ndev->stats.rx_bytes += len; napi_gro_receive(&priv->napi, skb); -refill: - ret = bcm_sysport_rx_refill(priv, cb); - if (ret) - priv->mib.alloc_rx_buff_failed++; +next: + processed++; + priv->rx_read_ptr++; + + if (priv->rx_read_ptr == priv->num_rx_bds) + priv->rx_read_ptr = 0; } return processed; From 25977ac77d62b3de19908979ac84c8fd5809de6f Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Thu, 28 May 2015 15:24:44 -0700 Subject: [PATCH 3/3] net: systemport: Add a check for oversized packets Occasionnaly we may get oversized packets from the hardware which exceed the nomimal 2KiB buffer size we allocate SKBs with. Add an early check which drops the packet to avoid invoking skb_over_panic() and move on to processing the next packet. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/bcmsysport.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index d777b0db9e63..909ad7a0d480 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -638,6 +638,14 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv, p_index, priv->rx_c_index, priv->rx_read_ptr, len, status); + if (unlikely(len > RX_BUF_LENGTH)) { + netif_err(priv, rx_status, ndev, "oversized packet\n"); + ndev->stats.rx_length_errors++; + ndev->stats.rx_errors++; + dev_kfree_skb_any(skb); + goto next; + } + if (unlikely(!(status & DESC_EOP) || !(status & DESC_SOP))) { netif_err(priv, rx_status, ndev, "fragmented packet!\n"); ndev->stats.rx_dropped++;