pasemi_mac: Logic cleanup / rx performance improvements
Logic cleanup and some performance enhancements to the RX path.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/pasemi_mac.c b/drivers/net/pasemi_mac.c
index f18fd07..6b4e925 100644
--- a/drivers/net/pasemi_mac.c
+++ b/drivers/net/pasemi_mac.c
@@ -305,19 +305,20 @@
struct pasemi_mac *mac = netdev_priv(dev);
unsigned int i;
int start = mac->rx->next_to_fill;
- unsigned int count;
+ unsigned int limit, count;
- count = (mac->rx->next_to_clean + RX_RING_SIZE -
+ limit = (mac->rx->next_to_clean + RX_RING_SIZE -
mac->rx->next_to_fill) & (RX_RING_SIZE - 1);
/* Check to see if we're doing first-time setup */
if (unlikely(mac->rx->next_to_clean == 0 && mac->rx->next_to_fill == 0))
- count = RX_RING_SIZE;
+ limit = RX_RING_SIZE;
- if (count <= 0)
+ if (limit <= 0)
return;
- for (i = start; i < start + count; i++) {
+ i = start;
+ for (count = limit; count; count--) {
struct pasemi_mac_buffer *info = &RX_DESC_INFO(mac, i);
u64 *buff = &RX_BUFF(mac, i);
struct sk_buff *skb;
@@ -335,27 +336,27 @@
dma = pci_map_single(mac->dma_pdev, skb->data, skb->len,
PCI_DMA_FROMDEVICE);
- if (dma_mapping_error(dma)) {
+ if (unlikely(dma_mapping_error(dma))) {
dev_kfree_skb_irq(info->skb);
- count = i - start;
break;
}
info->skb = skb;
info->dma = dma;
*buff = XCT_RXB_LEN(BUF_SIZE) | XCT_RXB_ADDR(dma);
+ i++;
}
wmb();
pci_write_config_dword(mac->dma_pdev,
PAS_DMA_RXCHAN_INCR(mac->dma_rxch),
- count);
+ limit - count);
pci_write_config_dword(mac->dma_pdev,
PAS_DMA_RXINT_INCR(mac->dma_if),
- count);
+ limit - count);
- mac->rx->next_to_fill += count;
+ mac->rx->next_to_fill += limit - count;
}
static void pasemi_mac_restart_rx_intr(struct pasemi_mac *mac)
@@ -393,32 +394,31 @@
}
-
static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)
{
- unsigned int i;
- int start, count;
+ unsigned int n;
+ int count;
+ struct pas_dma_xct_descr *dp;
+ struct pasemi_mac_buffer *info;
+ struct sk_buff *skb;
+ unsigned int i, len;
+ u64 macrx;
+ dma_addr_t dma;
spin_lock(&mac->rx->lock);
- start = mac->rx->next_to_clean;
- count = 0;
+ n = mac->rx->next_to_clean;
- for (i = start; i < (start + RX_RING_SIZE) && count < limit; i++) {
- struct pas_dma_xct_descr *dp;
- struct pasemi_mac_buffer *info;
- struct sk_buff *skb;
- unsigned int j, len;
- dma_addr_t dma;
+ for (count = limit; count; count--) {
rmb();
- dp = &RX_DESC(mac, i);
+ dp = &RX_DESC(mac, n);
+ macrx = dp->macrx;
- if (!(dp->macrx & XCT_MACRX_O))
+ if (!(macrx & XCT_MACRX_O))
break;
- count++;
info = NULL;
@@ -430,22 +430,20 @@
*/
dma = (dp->ptr & XCT_PTR_ADDR_M);
- for (j = start; j < (start + RX_RING_SIZE); j++) {
- info = &RX_DESC_INFO(mac, j);
+ for (i = n; i < (n + RX_RING_SIZE); i++) {
+ info = &RX_DESC_INFO(mac, i);
if (info->dma == dma)
break;
}
- BUG_ON(!info);
- BUG_ON(info->dma != dma);
skb = info->skb;
-
- pci_unmap_single(mac->dma_pdev, info->dma, info->skb->len,
- PCI_DMA_FROMDEVICE);
info->dma = 0;
+ pci_unmap_single(mac->dma_pdev, dma, skb->len,
+ PCI_DMA_FROMDEVICE);
- len = (dp->macrx & XCT_MACRX_LLEN_M) >> XCT_MACRX_LLEN_S;
+ len = (macrx & XCT_MACRX_LLEN_M) >> XCT_MACRX_LLEN_S;
+
if (len < 256) {
struct sk_buff *new_skb =
netdev_alloc_skb(mac->netdev, len + NET_IP_ALIGN);
@@ -465,9 +463,9 @@
skb->protocol = eth_type_trans(skb, mac->netdev);
- if ((dp->macrx & XCT_MACRX_HTY_M) == XCT_MACRX_HTY_IPV4_OK) {
+ if ((macrx & XCT_MACRX_HTY_M) == XCT_MACRX_HTY_IPV4_OK) {
skb->ip_summed = CHECKSUM_COMPLETE;
- skb->csum = (dp->macrx & XCT_MACRX_CSUM_M) >>
+ skb->csum = (macrx & XCT_MACRX_CSUM_M) >>
XCT_MACRX_CSUM_S;
} else
skb->ip_summed = CHECKSUM_NONE;
@@ -477,13 +475,13 @@
netif_receive_skb(skb);
- info->dma = 0;
- info->skb = NULL;
dp->ptr = 0;
dp->macrx = 0;
+
+ n++;
}
- mac->rx->next_to_clean += count;
+ mac->rx->next_to_clean += limit - count;
pasemi_mac_replenish_rx_ring(mac->netdev);
spin_unlock(&mac->rx->lock);
@@ -899,6 +897,9 @@
pkts = pasemi_mac_clean_rx(mac, limit);
+ dev->quota -= pkts;
+ *budget -= pkts;
+
if (pkts < limit) {
/* all done, no more packets present */
netif_rx_complete(dev);
@@ -907,8 +908,6 @@
return 0;
} else {
/* used up our quantum, so reschedule */
- dev->quota -= pkts;
- *budget -= pkts;
return 1;
}
}