sky2: use mask instead of modulo operation
Gcc isn't smart enough to know that it can do a modulo
operation with power of 2 constant by doing a mask.
So add macro to do it for us.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 4bb6ea1..d9cce50 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -79,6 +79,8 @@
#define NAPI_WEIGHT 64
#define PHY_RETRIES 1000
+#define RING_NEXT(x,s) (((x)+1) & ((s)-1))
+
static const u32 default_msg =
NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK
| NETIF_MSG_TIMER | NETIF_MSG_TX_ERR | NETIF_MSG_RX_ERR
@@ -719,7 +721,7 @@
{
struct sky2_tx_le *le = sky2->tx_le + sky2->tx_prod;
- sky2->tx_prod = (sky2->tx_prod + 1) % TX_RING_SIZE;
+ sky2->tx_prod = RING_NEXT(sky2->tx_prod, TX_RING_SIZE);
return le;
}
@@ -735,7 +737,7 @@
static inline struct sky2_rx_le *sky2_next_rx(struct sky2_port *sky2)
{
struct sky2_rx_le *le = sky2->rx_le + sky2->rx_put;
- sky2->rx_put = (sky2->rx_put + 1) % RX_LE_SIZE;
+ sky2->rx_put = RING_NEXT(sky2->rx_put, RX_LE_SIZE);
return le;
}
@@ -1078,7 +1080,7 @@
/* Modular subtraction in ring */
static inline int tx_dist(unsigned tail, unsigned head)
{
- return (head - tail) % TX_RING_SIZE;
+ return (head - tail) & (TX_RING_SIZE - 1);
}
/* Number of list elements available for next tx */
@@ -1255,7 +1257,7 @@
le->opcode = OP_BUFFER | HW_OWNER;
fre = sky2->tx_ring
- + ((re - sky2->tx_ring) + i + 1) % TX_RING_SIZE;
+ + RING_NEXT((re - sky2->tx_ring) + i, TX_RING_SIZE);
pci_unmap_addr_set(fre, mapaddr, mapping);
}
@@ -1315,7 +1317,7 @@
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
struct tx_ring_info *fre;
- fre = sky2->tx_ring + (put + i + 1) % TX_RING_SIZE;
+ fre = sky2->tx_ring + RING_NEXT(put + i, TX_RING_SIZE);
pci_unmap_page(pdev, pci_unmap_addr(fre, mapaddr),
skb_shinfo(skb)->frags[i].size,
PCI_DMA_TODEVICE);
@@ -1876,7 +1878,7 @@
break;
opcode &= ~HW_OWNER;
- hw->st_idx = (hw->st_idx + 1) % STATUS_RING_SIZE;
+ hw->st_idx = RING_NEXT(hw->st_idx, STATUS_RING_SIZE);
le->opcode = 0;
link = le->link;