arc_emac: fix compile-time errors & warnings on PPC64

As reported by "kbuild test robot" there were some errors and warnings
on attempt to build kernel with "make ARCH=powerpc allmodconfig".

And this patch addresses both errors and warnings.
Below is a list of introduced changes:
1. Fix compile-time errors (misspellings in "dma_unmap_single") on PPC.
2. Use DMA address instead of "skb->data" as a pointer to data buffer.
This fixed warnings on pointer to int conversion on 64-bit systems.
3. Re-implemented initial allocation of Rx buffers in "arc_emac_open" in
the same way they're re-allocated during operation (receiving packets).
So once again DMA address could be used instead of "skb->data".
4. Explicitly use EMAC_BUFFER_SIZE for Rx buffers allocation.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Cc: netdev@vger.kernel.org
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Francois Romieu <romieu@fr.zoreil.com>
Cc: Joe Perches <joe@perches.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Mischa Jonker <mjonker@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-kernel@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Florian Fainelli <florian@openwrt.org>
Cc: David Laight <david.laight@aculab.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 39 insertions, 26 deletions

diff --git a/drivers/net/ethernet/arc/emac_main.c b/drivers/net/ethernet/arc/emac_main.c
index 20345f6bf894..f1b121ee5525 100644
--- a/drivers/net/ethernet/arc/emac_main.c
+++ b/drivers/net/ethernet/arc/emac_main.c
@@ -171,8 +171,8 @@ static void arc_emac_tx_clean(struct net_device *ndev)
                         stats->tx_bytes += skb->len;
                 }
 
-                dma_unmap_single(&ndev->dev, dma_unmap_addr(&tx_buff, addr),
-                                 dma_unmap_len(&tx_buff, len), DMA_TO_DEVICE);
+                dma_unmap_single(&ndev->dev, dma_unmap_addr(tx_buff, addr),
+                                 dma_unmap_len(tx_buff, len), DMA_TO_DEVICE);
 
                 /* return the sk_buff to system */
                 dev_kfree_skb_irq(skb);
@@ -204,7 +204,6 @@ static int arc_emac_rx(struct net_device *ndev, int budget)
                 struct net_device_stats *stats = &priv->stats;
                 struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];
                 struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];
-                unsigned int buflen = EMAC_BUFFER_SIZE;
                 unsigned int pktlen, info = le32_to_cpu(rxbd->info);
                 struct sk_buff *skb;
                 dma_addr_t addr;
@@ -226,7 +225,7 @@ static int arc_emac_rx(struct net_device *ndev, int budget)
                                 netdev_err(ndev, "incomplete packet received\n");
 
                         /* Return ownership to EMAC */
-                        rxbd->info = cpu_to_le32(FOR_EMAC | buflen);
+                        rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
                         stats->rx_errors++;
                         stats->rx_length_errors++;
                         continue;
@@ -240,11 +239,12 @@ static int arc_emac_rx(struct net_device *ndev, int budget)
                 skb->dev = ndev;
                 skb->protocol = eth_type_trans(skb, ndev);
 
-                dma_unmap_single(&ndev->dev, dma_unmap_addr(&rx_buff, addr),
-                                 dma_unmap_len(&rx_buff, len), DMA_FROM_DEVICE);
+                dma_unmap_single(&ndev->dev, dma_unmap_addr(rx_buff, addr),
+                                 dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE);
 
                 /* Prepare the BD for next cycle */
-                rx_buff->skb = netdev_alloc_skb_ip_align(ndev, buflen);
+                rx_buff->skb = netdev_alloc_skb_ip_align(ndev,
+                                                         EMAC_BUFFER_SIZE);
                 if (unlikely(!rx_buff->skb)) {
                         stats->rx_errors++;
                         /* Because receive_skb is below, increment rx_dropped */
@@ -256,7 +256,7 @@ static int arc_emac_rx(struct net_device *ndev, int budget)
                 netif_receive_skb(skb);
 
                 addr = dma_map_single(&ndev->dev, (void *)rx_buff->skb->data,
-                                      buflen, DMA_FROM_DEVICE);
+                                      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
                 if (dma_mapping_error(&ndev->dev, addr)) {
                         if (net_ratelimit())
                                 netdev_err(ndev, "cannot dma map\n");
@@ -264,16 +264,16 @@ static int arc_emac_rx(struct net_device *ndev, int budget)
                         stats->rx_errors++;
                         continue;
                 }
-                dma_unmap_addr_set(&rx_buff, mapping, addr);
-                dma_unmap_len_set(&rx_buff, len, buflen);
+                dma_unmap_addr_set(rx_buff, addr, addr);
+                dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);
 
-                rxbd->data = cpu_to_le32(rx_buff->skb->data);
+                rxbd->data = cpu_to_le32(addr);
 
                 /* Make sure pointer to data buffer is set */
                 wmb();
 
                 /* Return ownership to EMAC */
-                rxbd->info = cpu_to_le32(FOR_EMAC | buflen);
+                rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
         }
 
         return work_done;
@@ -376,8 +376,6 @@ static int arc_emac_open(struct net_device *ndev)
 {
         struct arc_emac_priv *priv = netdev_priv(ndev);
         struct phy_device *phy_dev = priv->phy_dev;
-        struct arc_emac_bd *bd;
-        struct sk_buff *skb;
         int i;
 
         phy_dev->autoneg = AUTONEG_ENABLE;
@@ -395,25 +393,40 @@ static int arc_emac_open(struct net_device *ndev)
                 }
         }
 
+        priv->last_rx_bd = 0;
+
         /* Allocate and set buffers for Rx BD's */
-        bd = priv->rxbd;
         for (i = 0; i < RX_BD_NUM; i++) {
-                skb = netdev_alloc_skb_ip_align(ndev, EMAC_BUFFER_SIZE);
-                if (unlikely(!skb))
+                dma_addr_t addr;
+                unsigned int *last_rx_bd = &priv->last_rx_bd;
+                struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];
+                struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];
+
+                rx_buff->skb = netdev_alloc_skb_ip_align(ndev,
+                                                         EMAC_BUFFER_SIZE);
+                if (unlikely(!rx_buff->skb))
+                        return -ENOMEM;
+
+                addr = dma_map_single(&ndev->dev, (void *)rx_buff->skb->data,
+                                      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
+                if (dma_mapping_error(&ndev->dev, addr)) {
+                        netdev_err(ndev, "cannot dma map\n");
+                        dev_kfree_skb(rx_buff->skb);
                         return -ENOMEM;
+                }
+                dma_unmap_addr_set(rx_buff, addr, addr);
+                dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);
 
-                priv->rx_buff[i].skb = skb;
-                bd->data = cpu_to_le32(skb->data);
+                rxbd->data = cpu_to_le32(addr);
 
                 /* Make sure pointer to data buffer is set */
                 wmb();
 
-                /* Set ownership to EMAC */
-                bd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
-                bd++;
-        }
+                /* Return ownership to EMAC */
+                rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
 
-        priv->last_rx_bd = 0;
+                *last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;
+        }
 
         /* Clean Tx BD's */
         memset(priv->txbd, 0, TX_RING_SZ);
@@ -543,11 +556,11 @@ static int arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
                 dev_kfree_skb(skb);
                 return NETDEV_TX_OK;
         }
-        dma_unmap_addr_set(&priv->tx_buff[*txbd_curr], mapping, addr);
+        dma_unmap_addr_set(&priv->tx_buff[*txbd_curr], addr, addr);
         dma_unmap_len_set(&priv->tx_buff[*txbd_curr], len, len);
 
         priv->tx_buff[*txbd_curr].skb = skb;
-        priv->txbd[*txbd_curr].data = cpu_to_le32(skb->data);
+        priv->txbd[*txbd_curr].data = cpu_to_le32(addr);
 
         /* Make sure pointer to data buffer is set */
         wmb();