Merge branch 'systemport-next'

Florian Fainelli says:

====================
net: systemport: misc improvements

These patches are highly inspired by changes from Petri on bcmgenet, last patch
is a misc fix that I had pending for a while, but is not a candidate for 'net'
at this point.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 58 insertions, 51 deletions

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index 084a50a555de..909ad7a0d480 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -524,67 +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;
         }
 
-        dma_unmap_addr_set(cb, dma_addr, mapping);
-        dma_desc_set_addr(priv, priv->rx_bd_assign_ptr, mapping);
+        /* 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);
 
-        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);
+        /* 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[priv->rx_bd_assign_index];
-                if (cb->skb)
-                        continue;
-
-                ret = bcm_sysport_rx_refill(priv, cb);
-                if (ret)
-                        break;
+                cb = &priv->rx_cbs[i];
+                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;
@@ -592,7 +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);
@@ -610,13 +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
@@ -627,12 +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;
@@ -644,12 +638,20 @@ 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++;
                         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))) {
@@ -658,8 +660,8 @@ 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);
@@ -686,10 +688,12 @@ 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;
@@ -1330,14 +1334,14 @@ 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 +1351,11 @@ 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;