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Subject[PATCH v2 net-next 04/15] net: sgi: ioc3-eth: use defines for constants dealing with desc rings
Date
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>
---
drivers/net/ethernet/sgi/ioc3-eth.c | 42 +++++++++++++++++++++----------------
1 file changed, 24 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/sgi/ioc3-eth.c b/drivers/net/ethernet/sgi/ioc3-eth.c
index 51cc1389e204..ba18a53fbbe6 100644
--- 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 @@ static inline void ioc3_rx(struct net_device *dev)
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);
--
2.13.7
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