net: sgi: ioc3-eth: refactor rx buffer allocation

Move common code for rx buffer setup into ioc3_alloc_skb and deal
with allocation failures. Also clean up allocation size calculation.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sgi/ioc3-eth.c b/drivers/net/ethernet/sgi/ioc3-eth.c
index fe8ee8f1c71f5992b356f2c5096dc83fdc51be09..7531944d2e95e9f6d44bc7f579c5c813cf421c42 100644 (file)
--- a/drivers/net/ethernet/sgi/ioc3-eth.c
+++ b/drivers/net/ethernet/sgi/ioc3-eth.c
@@ -11,11 +11,8 @@
  *
  * To do:
  *
- *  o Handle allocation failures in ioc3_alloc_skb() more gracefully.
- *  o Handle allocation failures in ioc3_init_rings().
  *  o Use prefetching for large packets.  What is a good lower limit for
  *    prefetching?
- *  o We're probably allocating a bit too much memory.
  *  o Use hardware checksums.
  *  o Convert to using a IOC3 meta driver.
  *  o Which PHYs might possibly be attached to the IOC3 in real live,
@@ -72,6 +69,13 @@
 #define TX_RING_ENTRIES                128
 #define TX_RING_MASK           (TX_RING_ENTRIES - 1)
 
+/* IOC3 does dma transfers in 128 byte blocks */
+#define IOC3_DMA_XFER_LEN      128UL
+
+/* Every RX buffer starts with 8 byte descriptor data */
+#define RX_OFFSET              (sizeof(struct ioc3_erxbuf) + NET_IP_ALIGN)
+#define RX_BUF_SIZE            (13 * IOC3_DMA_XFER_LEN)
+
 #define ETCSR_FD   ((17 << ETCSR_IPGR2_SHIFT) | (11 << ETCSR_IPGR1_SHIFT) | 21)
 #define ETCSR_HD   ((21 << ETCSR_IPGR2_SHIFT) | (21 << ETCSR_IPGR1_SHIFT) | 21)
 
@@ -108,36 +112,38 @@ static inline unsigned int ioc3_hash(const unsigned char *addr);
 static void ioc3_start(struct ioc3_private *ip);
 static inline void ioc3_stop(struct ioc3_private *ip);
 static void ioc3_init(struct net_device *dev);
-static void ioc3_alloc_rx_bufs(struct net_device *dev);
+static int ioc3_alloc_rx_bufs(struct net_device *dev);
 static void ioc3_free_rx_bufs(struct ioc3_private *ip);
 static inline void ioc3_clean_tx_ring(struct ioc3_private *ip);
 
 static const char ioc3_str[] = "IOC3 Ethernet";
 static const struct ethtool_ops ioc3_ethtool_ops;
 
-/* We use this to acquire receive skb's that we can DMA directly into. */
-
-#define IOC3_CACHELINE 128UL
 
 static inline unsigned long aligned_rx_skb_addr(unsigned long addr)
 {
-       return (~addr + 1) & (IOC3_CACHELINE - 1UL);
+       return (~addr + 1) & (IOC3_DMA_XFER_LEN - 1UL);
 }
 
-static inline struct sk_buff *ioc3_alloc_skb(unsigned long length,
-                                            unsigned int gfp_mask)
+static inline int ioc3_alloc_skb(struct sk_buff **skb, struct ioc3_erxbuf **rxb)
 {
-       struct sk_buff *skb;
+       struct sk_buff *new_skb;
+       int offset;
 
-       skb = alloc_skb(length + IOC3_CACHELINE - 1, gfp_mask);
-       if (likely(skb)) {
-               int offset = aligned_rx_skb_addr((unsigned long)skb->data);
+       new_skb = alloc_skb(RX_BUF_SIZE + IOC3_DMA_XFER_LEN - 1, GFP_ATOMIC);
+       if (!new_skb)
+               return -ENOMEM;
 
-               if (offset)
-                       skb_reserve(skb, offset);
-       }
+       /* ensure buffer is aligned to IOC3_DMA_XFER_LEN */
+       offset = aligned_rx_skb_addr((unsigned long)new_skb->data);
+       if (offset)
+               skb_reserve(new_skb, offset);
+
+       *rxb = (struct ioc3_erxbuf *)new_skb->data;
+       skb_reserve(new_skb, RX_OFFSET);
+       *skb = new_skb;
 
-       return skb;
+       return 0;
 }
 
 static inline unsigned long ioc3_map(void *ptr, unsigned long vdev)
@@ -151,13 +157,6 @@ static inline unsigned long ioc3_map(void *ptr, unsigned long vdev)
        return virt_to_bus(ptr);
 #endif
 }
-
-/* BEWARE: The IOC3 documentation documents the size of rx buffers as
- * 1644 while it's actually 1664.  This one was nasty to track down ...
- */
-#define RX_OFFSET              10
-#define RX_BUF_ALLOC_SIZE      (1664 + RX_OFFSET + IOC3_CACHELINE)
-
 #define IOC3_SIZE 0x100000
 
 static inline u32 mcr_pack(u32 pulse, u32 sample)
@@ -538,11 +537,10 @@ static inline void ioc3_rx(struct net_device *dev)
                err = be32_to_cpu(rxb->err);            /* It's valid ...  */
                if (err & ERXBUF_GOODPKT) {
                        len = ((w0 >> ERXBUF_BYTECNT_SHIFT) & 0x7ff) - 4;
-                       skb_trim(skb, len);
+                       skb_put(skb, len);
                        skb->protocol = eth_type_trans(skb, dev);
 
-                       new_skb = ioc3_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
-                       if (!new_skb) {
+                       if (ioc3_alloc_skb(&new_skb, &rxb)) {
                                /* Ouch, drop packet and just recycle packet
                                 * to keep the ring filled.
                                 */
@@ -560,11 +558,6 @@ static inline void ioc3_rx(struct net_device *dev)
 
                        ip->rx_skbs[rx_entry] = NULL;   /* Poison  */
 
-                       /* Because we reserve afterwards. */
-                       skb_put(new_skb, (1664 + RX_OFFSET));
-                       rxb = (struct ioc3_erxbuf *)new_skb->data;
-                       skb_reserve(new_skb, RX_OFFSET);
-
                        dev->stats.rx_packets++;                /* Statistics */
                        dev->stats.rx_bytes += len;
                } else {
@@ -667,7 +660,11 @@ static void ioc3_error(struct net_device *dev, u32 eisr)
        ioc3_clean_tx_ring(ip);
 
        ioc3_init(dev);
-       ioc3_alloc_rx_bufs(dev);
+       if (ioc3_alloc_rx_bufs(dev)) {
+               netdev_err(dev, "%s: rx buffer allocation failed\n", __func__);
+               spin_unlock(&ip->ioc3_lock);
+               return;
+       }
        ioc3_start(ip);
        ioc3_mii_init(ip);
 
@@ -801,7 +798,7 @@ static void ioc3_free_rx_bufs(struct ioc3_private *ip)
        }
 }
 
-static void ioc3_alloc_rx_bufs(struct net_device *dev)
+static int ioc3_alloc_rx_bufs(struct net_device *dev)
 {
        struct ioc3_private *ip = netdev_priv(dev);
        struct ioc3_erxbuf *rxb;
@@ -812,25 +809,16 @@ static void ioc3_alloc_rx_bufs(struct net_device *dev)
         * this for performance and memory later.
         */
        for (i = 0; i < RX_BUFFS; i++) {
-               struct sk_buff *skb;
-
-               skb = ioc3_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
-               if (!skb) {
-                       show_free_areas(0, NULL);
-                       continue;
-               }
-
-               ip->rx_skbs[i] = skb;
+               if (ioc3_alloc_skb(&ip->rx_skbs[i], &rxb))
+                       return -ENOMEM;
 
-               /* Because we reserve afterwards. */
-               skb_put(skb, (1664 + RX_OFFSET));
-               rxb = (struct ioc3_erxbuf *)skb->data;
                rxb->w0 = 0;    /* Clear valid flag */
                ip->rxr[i] = cpu_to_be64(ioc3_map(rxb, 1));
-               skb_reserve(skb, RX_OFFSET);
        }
        ip->rx_ci = 0;
        ip->rx_pi = RX_BUFFS;
+
+       return 0;
 }
 
 static inline void ioc3_ssram_disc(struct ioc3_private *ip)
@@ -942,7 +930,10 @@ static int ioc3_open(struct net_device *dev)
        ip->ehar_l = 0;
 
        ioc3_init(dev);
-       ioc3_alloc_rx_bufs(dev);
+       if (ioc3_alloc_rx_bufs(dev)) {
+               netdev_err(dev, "%s: rx buffer allocation failed\n", __func__);
+               return -ENOMEM;
+       }
        ioc3_start(ip);
        ioc3_mii_start(ip);
 
@@ -1435,7 +1426,11 @@ static void ioc3_timeout(struct net_device *dev)
        ioc3_clean_tx_ring(ip);
 
        ioc3_init(dev);
-       ioc3_alloc_rx_bufs(dev);
+       if (ioc3_alloc_rx_bufs(dev)) {
+               netdev_err(dev, "%s: rx buffer allocation failed\n", __func__);
+               spin_unlock_irq(&ip->ioc3_lock);
+               return;
+       }
        ioc3_start(ip);
        ioc3_mii_init(ip);
        ioc3_mii_start(ip);