[PATCH] S2io: Performance improvements
Hi,
This patch relates to mostly performance related changes.
1. Fixed incorrect computation of PANIC level in rx_buffer_level().
2. Removed unnecessary PIOs(read/write of tx_traffic_int and
rx_traffic_int) from interrupt handler and removed read of
general_int_status register from xmit routine.
3. Enable two-buffer mode(for Rx path) automatically for SGI
systems. This improves Rx performance dramatically on
SGI systems.
Signed-off-by: Ravinandan Arakali <ravinandan.arakali@neterion.com>
Signed-off-by: Raghavendra Koushik <raghavendra.koushik@neterion.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 6668b99..28d6d374 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -100,8 +100,7 @@
mac_control = &sp->mac_control;
if ((mac_control->rings[ring].pkt_cnt - rxb_size) > 16) {
level = LOW;
- if ((mac_control->rings[ring].pkt_cnt - rxb_size) <
- MAX_RXDS_PER_BLOCK) {
+ if (rxb_size <= MAX_RXDS_PER_BLOCK) {
level = PANIC;
}
}
@@ -2193,7 +2192,6 @@
{
nic_t *nic = ring_data->nic;
struct net_device *dev = (struct net_device *) nic->dev;
- XENA_dev_config_t __iomem *bar0 = nic->bar0;
int get_block, get_offset, put_block, put_offset, ring_bufs;
rx_curr_get_info_t get_info, put_info;
RxD_t *rxdp;
@@ -2201,8 +2199,6 @@
#ifndef CONFIG_S2IO_NAPI
int pkt_cnt = 0;
#endif
- register u64 val64;
-
spin_lock(&nic->rx_lock);
if (atomic_read(&nic->card_state) == CARD_DOWN) {
DBG_PRINT(ERR_DBG, "%s: %s going down for reset\n",
@@ -2210,13 +2206,6 @@
spin_unlock(&nic->rx_lock);
}
- /*
- * rx_traffic_int reg is an R1 register, hence we read and write
- * back the same value in the register to clear it
- */
- val64 = readq(&bar0->tx_traffic_int);
- writeq(val64, &bar0->tx_traffic_int);
-
get_info = ring_data->rx_curr_get_info;
get_block = get_info.block_index;
put_info = ring_data->rx_curr_put_info;
@@ -2312,20 +2301,11 @@
static void tx_intr_handler(fifo_info_t *fifo_data)
{
nic_t *nic = fifo_data->nic;
- XENA_dev_config_t __iomem *bar0 = nic->bar0;
struct net_device *dev = (struct net_device *) nic->dev;
tx_curr_get_info_t get_info, put_info;
struct sk_buff *skb;
TxD_t *txdlp;
u16 j, frg_cnt;
- register u64 val64 = 0;
-
- /*
- * tx_traffic_int reg is an R1 register, hence we read and write
- * back the same value in the register to clear it
- */
- val64 = readq(&bar0->tx_traffic_int);
- writeq(val64, &bar0->tx_traffic_int);
get_info = fifo_data->tx_curr_get_info;
put_info = fifo_data->tx_curr_put_info;
@@ -2818,7 +2798,6 @@
#endif
mac_info_t *mac_control;
struct config_param *config;
- XENA_dev_config_t __iomem *bar0 = sp->bar0;
mac_control = &sp->mac_control;
config = &sp->config;
@@ -2870,7 +2849,6 @@
}
txdp->Control_2 |= config->tx_intr_type;
-
txdp->Control_1 |= (TXD_BUFFER0_SIZE(frg_len) |
TXD_GATHER_CODE_FIRST);
txdp->Control_1 |= TXD_LIST_OWN_XENA;
@@ -2890,6 +2868,8 @@
val64 = mac_control->fifos[queue].list_info[put_off].list_phy_addr;
writeq(val64, &tx_fifo->TxDL_Pointer);
+ wmb();
+
val64 = (TX_FIFO_LAST_TXD_NUM(frg_cnt) | TX_FIFO_FIRST_LIST |
TX_FIFO_LAST_LIST);
@@ -2899,9 +2879,6 @@
#endif
writeq(val64, &tx_fifo->List_Control);
- /* Perform a PCI read to flush previous writes */
- val64 = readq(&bar0->general_int_status);
-
put_off++;
put_off %= mac_control->fifos[queue].tx_curr_put_info.fifo_len + 1;
mac_control->fifos[queue].tx_curr_put_info.offset = put_off;
@@ -2940,7 +2917,7 @@
nic_t *sp = dev->priv;
XENA_dev_config_t __iomem *bar0 = sp->bar0;
int i;
- u64 reason = 0;
+ u64 reason = 0, val64;
mac_info_t *mac_control;
struct config_param *config;
@@ -2978,6 +2955,13 @@
#else
/* If Intr is because of Rx Traffic */
if (reason & GEN_INTR_RXTRAFFIC) {
+ /*
+ * rx_traffic_int reg is an R1 register, writing all 1's
+ * will ensure that the actual interrupt causing bit get's
+ * cleared and hence a read can be avoided.
+ */
+ val64 = 0xFFFFFFFFFFFFFFFFULL;
+ writeq(val64, &bar0->rx_traffic_int);
for (i = 0; i < config->rx_ring_num; i++) {
rx_intr_handler(&mac_control->rings[i]);
}
@@ -2986,6 +2970,14 @@
/* If Intr is because of Tx Traffic */
if (reason & GEN_INTR_TXTRAFFIC) {
+ /*
+ * tx_traffic_int reg is an R1 register, writing all 1's
+ * will ensure that the actual interrupt causing bit get's
+ * cleared and hence a read can be avoided.
+ */
+ val64 = 0xFFFFFFFFFFFFFFFFULL;
+ writeq(val64, &bar0->tx_traffic_int);
+
for (i = 0; i < config->tx_fifo_num; i++)
tx_intr_handler(&mac_control->fifos[i]);
}