net: sgi: ioc3-eth: use defines for constants dealing with desc rings

Descriptor ring sizes of the IOC3 are more or less fixed size. To
make clearer where there is a relation to ring sizes use defines.

Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
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 51cc138..ba18a53 100644 (file)
--- a/drivers/net/ethernet/sgi/ioc3-eth.c
+++ b/drivers/net/ethernet/sgi/ioc3-eth.c
@@ -61,10 +61,16 @@
 #include <asm/sn/ioc3.h>
 #include <asm/pci/bridge.h>
 
-/* 64 RX buffers.  This is tunable in the range of 16 <= x < 512.  The
- * value must be a power of two.
+/* Number of RX buffers.  This is tunable in the range of 16 <= x < 512.
+ * The value must be a power of two.
  */
-#define RX_BUFFS 64
+#define RX_BUFFS               64
+#define RX_RING_ENTRIES                512             /* fixed in hardware */
+#define RX_RING_MASK           (RX_RING_ENTRIES - 1)
+
+/* 128 TX buffers (not tunable) */
+#define TX_RING_ENTRIES                128
+#define TX_RING_MASK           (TX_RING_ENTRIES - 1)
 
 #define ETCSR_FD   ((17 << ETCSR_IPGR2_SHIFT) | (11 << ETCSR_IPGR1_SHIFT) | 21)
 #define ETCSR_HD   ((21 << ETCSR_IPGR2_SHIFT) | (21 << ETCSR_IPGR1_SHIFT) | 21)
@@ -76,8 +82,8 @@ struct ioc3_private {
        u32 *ssram;
        unsigned long *rxr;             /* pointer to receiver ring */
        struct ioc3_etxd *txr;
-       struct sk_buff *rx_skbs[512];
-       struct sk_buff *tx_skbs[128];
+       struct sk_buff *rx_skbs[RX_RING_ENTRIES];
+       struct sk_buff *tx_skbs[TX_RING_ENTRIES];
        int rx_ci;                      /* RX consumer index */
        int rx_pi;                      /* RX producer index */
        int tx_ci;                      /* TX consumer index */
@@ -573,10 +579,10 @@ next:
                ip->rx_skbs[n_entry] = new_skb;
                rxr[n_entry] = cpu_to_be64(ioc3_map(rxb, 1));
                rxb->w0 = 0;                            /* Clear valid flag */
-               n_entry = (n_entry + 1) & 511;          /* Update erpir */
+               n_entry = (n_entry + 1) & RX_RING_MASK; /* Update erpir */
 
                /* Now go on to the next ring entry.  */
-               rx_entry = (rx_entry + 1) & 511;
+               rx_entry = (rx_entry + 1) & RX_RING_MASK;
                skb = ip->rx_skbs[rx_entry];
                rxb = (struct ioc3_erxbuf *)(skb->data - RX_OFFSET);
                w0 = be32_to_cpu(rxb->w0);
@@ -598,7 +604,7 @@ static inline void ioc3_tx(struct net_device *dev)
        spin_lock(&ip->ioc3_lock);
        etcir = readl(&regs->etcir);
 
-       tx_entry = (etcir >> 7) & 127;
+       tx_entry = (etcir >> 7) & TX_RING_MASK;
        o_entry = ip->tx_ci;
        packets = 0;
        bytes = 0;
@@ -610,17 +616,17 @@ static inline void ioc3_tx(struct net_device *dev)
                dev_consume_skb_irq(skb);
                ip->tx_skbs[o_entry] = NULL;
 
-               o_entry = (o_entry + 1) & 127;          /* Next */
+               o_entry = (o_entry + 1) & TX_RING_MASK; /* Next */
 
                etcir = readl(&regs->etcir);            /* More pkts sent?  */
-               tx_entry = (etcir >> 7) & 127;
+               tx_entry = (etcir >> 7) & TX_RING_MASK;
        }
 
        dev->stats.tx_packets += packets;
        dev->stats.tx_bytes += bytes;
        ip->txqlen -= packets;
 
-       if (ip->txqlen < 128)
+       if (netif_queue_stopped(dev) && ip->txqlen < TX_RING_ENTRIES)
                netif_wake_queue(dev);
 
        ip->tx_ci = o_entry;
@@ -765,10 +771,10 @@ static inline void ioc3_clean_rx_ring(struct ioc3_private *ip)
                ip->rx_skbs[ip->rx_pi] = ip->rx_skbs[ip->rx_ci];
                ip->rxr[ip->rx_pi++] = ip->rxr[ip->rx_ci++];
        }
-       ip->rx_pi &= 511;
-       ip->rx_ci &= 511;
+       ip->rx_pi &= RX_RING_MASK;
+       ip->rx_ci &= RX_RING_MASK;
 
-       for (i = ip->rx_ci; i != ip->rx_pi; i = (i + 1) & 511) {
+       for (i = ip->rx_ci; i != ip->rx_pi; i = (i + 1) & RX_RING_MASK) {
                skb = ip->rx_skbs[i];
                rxb = (struct ioc3_erxbuf *)(skb->data - RX_OFFSET);
                rxb->w0 = 0;
@@ -780,7 +786,7 @@ static inline void ioc3_clean_tx_ring(struct ioc3_private *ip)
        struct sk_buff *skb;
        int i;
 
-       for (i = 0; i < 128; i++) {
+       for (i = 0; i < TX_RING_ENTRIES; i++) {
                skb = ip->tx_skbs[i];
                if (skb) {
                        ip->tx_skbs[i] = NULL;
@@ -812,7 +818,7 @@ static void ioc3_free_rings(struct ioc3_private *ip)
                        if (skb)
                                dev_kfree_skb_any(skb);
 
-                       n_entry = (n_entry + 1) & 511;
+                       n_entry = (n_entry + 1) & RX_RING_MASK;
                }
                free_page((unsigned long)ip->rxr);
                ip->rxr = NULL;
@@ -1425,13 +1431,13 @@ static netdev_tx_t ioc3_start_xmit(struct sk_buff *skb, struct net_device *dev)
        mb(); /* make sure all descriptor changes are visible */
 
        ip->tx_skbs[produce] = skb;                     /* Remember skb */
-       produce = (produce + 1) & 127;
+       produce = (produce + 1) & TX_RING_MASK;
        ip->tx_pi = produce;
        writel(produce << 7, &ip->regs->etpir);         /* Fire ... */
 
        ip->txqlen++;
 
-       if (ip->txqlen >= 127)
+       if (ip->txqlen >= (TX_RING_ENTRIES - 1))
                netif_stop_queue(dev);
 
        spin_unlock_irq(&ip->ioc3_lock);