Hi,
you'll find here a patch I've made to add the CONFIG_NET_HW_FLOWCONTROL
support to the e1000 driver (against version 5.2.16).
Without CONFIG_NET_HW_FLOWCONTROL, the system will collapse when you load
it at Gigabit speed with small frames (only a few fps rate).
Thanks to CONFIG_NET_HW_FLOWCONTROL, it can keep a very good rate (200k
fps forwarding small packets in my test system) even with 100% load.
This patch has been made against the 5.2.16 Intel driver downloaded from
their web site. Patching the driver incorporated into recent kernels may
require some modifications.
diff -u -r e1000-5.2.16/src/e1000.h e1000-5.2.16_fc/src/e1000.h
--- e1000-5.2.16/src/e1000.h Sat Aug 9 01:46:40 2003
+++ e1000-5.2.16_fc/src/e1000.h Wed Sep 24 09:14:18 2003
@@ -255,5 +255,9 @@
#endif
uint32_t pci_state[16];
+
+#ifdef CONFIG_NET_HW_FLOWCONTROL
+ int fc_bit;
+#endif
};
#endif /* _E1000_H_ */
diff -u -r e1000-5.2.16/src/e1000_main.c e1000-5.2.16_fc/src/e1000_main.c
--- e1000-5.2.16/src/e1000_main.c Sat Aug 9 01:46:40 2003
+++ e1000-5.2.16_fc/src/e1000_main.c Fri Sep 26 15:25:25 2003
@@ -142,6 +142,10 @@
static void e1000_update_stats(struct e1000_adapter *adapter);
static inline void e1000_irq_disable(struct e1000_adapter *adapter);
static inline void e1000_irq_enable(struct e1000_adapter *adapter);
+#ifdef CONFIG_NET_HW_FLOWCONTROL
+static inline void e1000_irq_disable_rx(struct e1000_adapter *adapter);
+static inline void e1000_irq_enable_rx(struct e1000_adapter *adapter);
+#endif
static irqreturn_t e1000_intr(int irq, void *data, struct pt_regs *regs);
static boolean_t e1000_clean_tx_irq(struct e1000_adapter *adapter);
#ifdef CONFIG_E1000_NAPI
@@ -284,6 +288,7 @@
struct net_device *netdev = adapter->netdev;
e1000_irq_disable(adapter);
+
free_irq(netdev->irq, netdev);
del_timer_sync(&adapter->tx_fifo_stall_timer);
del_timer_sync(&adapter->watchdog_timer);
@@ -675,6 +680,18 @@
return 0;
}
+#ifdef CONFIG_NET_HW_FLOWCONTROL
+static void e1000_xon(struct net_device *netdev)
+{
+ struct e1000_adapter *adapter = netdev->priv;
+
+ clear_bit(adapter->fc_bit, &netdev_fc_xoff);
+ if (netif_running(netdev)) {
+ e1000_irq_enable_rx(adapter);
+ }
+}
+#endif
+
/**
* e1000_open - Called when a network interface is made active
* @netdev: network interface device structure
@@ -693,6 +710,10 @@
{
struct e1000_adapter *adapter = netdev->priv;
+#ifdef CONFIG_NET_HW_FLOWCONTROL
+ adapter->fc_bit = netdev_register_fc(netdev, e1000_xon);
+#endif
+
/* allocate transmit descriptors */
if(e1000_setup_tx_resources(adapter))
@@ -735,6 +756,15 @@
{
struct e1000_adapter *adapter = netdev->priv;
+#ifdef CONFIG_NET_HW_FLOWCONTROL
+ if (adapter->fc_bit) {
+ int bit = adapter->fc_bit;
+
+ adapter->fc_bit = 0;
+ netdev_unregister_fc(bit);
+ }
+#endif
+
e1000_down(adapter);
e1000_free_tx_resources(adapter);
@@ -2067,6 +2097,26 @@
}
}
+#ifdef CONFIG_NET_HW_FLOWCONTROL
+static inline void
+e1000_irq_disable_rx(struct e1000_adapter *adapter)
+{
+ if (atomic_read(&adapter->irq_sem)==0) {
+ E1000_WRITE_REG(&adapter->hw, IMC, E1000_IMC_RXT0);
+ E1000_WRITE_FLUSH(&adapter->hw);
+ }
+}
+
+static inline void
+e1000_irq_enable_rx(struct e1000_adapter *adapter)
+{
+ if (atomic_read(&adapter->irq_sem)==0) {
+ E1000_WRITE_REG(&adapter->hw, IMS, E1000_IMS_RXT0);
+ E1000_WRITE_FLUSH(&adapter->hw);
+ }
+}
+#endif //CONFIG_NET_HW_FLOWCONTROL
+
/**
* e1000_intr - Interrupt Handler
* @irq: interrupt number
@@ -2082,7 +2132,8 @@
uint32_t icr = E1000_READ_REG(&adapter->hw, ICR);
#ifndef CONFIG_E1000_NAPI
unsigned int i;
-#endif
+#endif
+ int rx_res, tx_res;
if(!icr)
return IRQ_NONE; /* Not our interrupt */
@@ -2104,10 +2155,19 @@
__netif_rx_schedule(netdev);
}
#else
- for(i = 0; i < E1000_MAX_INTR; i++)
- if(!e1000_clean_rx_irq(adapter) &
- !e1000_clean_tx_irq(adapter))
+ for(i = 0; i < E1000_MAX_INTR; i++) {
+ rx_res = tx_res = 0;
+#ifdef CONFIG_NET_HW_FLOWCONTROL
+ if ( (!adapter->fc_bit) ||
+ (!test_bit(adapter->fc_bit, &netdev_fc_xoff)))
+#endif
+ rx_res = e1000_clean_rx_irq(adapter);
+
+ tx_res = e1000_clean_tx_irq(adapter);
+
+ if (!rx_res && !tx_res)
break;
+ }
#endif
#ifdef E1000_COUNT_ICR
adapter->icr_txdw += icr & 0x01;
@@ -2249,6 +2309,7 @@
uint8_t last_byte;
unsigned int i;
boolean_t cleaned = FALSE;
+ int netif_rx_result = NET_RX_SUCCESS;
i = rx_ring->next_to_clean;
rx_desc = E1000_RX_DESC(*rx_ring, i);
@@ -2263,8 +2324,6 @@
(*work_done)++;
#endif
- cleaned = TRUE;
-
pci_unmap_single(pdev,
buffer_info->dma,
buffer_info->length,
@@ -2273,16 +2332,29 @@
skb = buffer_info->skb;
length = le16_to_cpu(rx_desc->length);
+#ifdef CONFIG_NET_HW_FLOWCONTROL
+ if (atomic_read(&netdev_dropping)) {
+ dev_kfree_skb_irq(skb);
+ buffer_info->skb = NULL;
+ rx_desc->status = 0;
+
+ goto e1000_throttle;
+ }
+#endif
+
+ cleaned = TRUE;
+
if(!(rx_desc->status & E1000_RXD_STAT_EOP)) {
/* All receives must fit into a single buffer */
E1000_DBG("Receive packet consumed multiple buffers\n");
-
+
dev_kfree_skb_irq(skb);
- rx_desc->status = 0;
buffer_info->skb = NULL;
+ rx_desc->status = 0;
+
if(++i == rx_ring->count) i = 0;
rx_desc = E1000_RX_DESC(*rx_ring, i);
@@ -2344,16 +2416,27 @@
le16_to_cpu(rx_desc->special &
E1000_RXD_SPC_VLAN_MASK));
} else {
- netif_rx(skb);
+ netif_rx_result = netif_rx(skb);
}
#else
- netif_rx(skb);
+ netif_rx_result = netif_rx(skb);
#endif
#endif /* CONFIG_E1000_NAPI */
netdev->last_rx = jiffies;
rx_desc->status = 0;
buffer_info->skb = NULL;
+
+#ifdef CONFIG_NET_HW_FLOWCONTROL
+ if (atomic_read(&netdev_dropping)) {
+e1000_throttle:
+ if (adapter->fc_bit) {
+ e1000_irq_disable_rx(adapter);
+ set_bit(adapter->fc_bit, &netdev_fc_xoff);
+ }
+ cleaned = FALSE;
+ }
+#endif
if(++i == rx_ring->count) i = 0;
---
Daniel FAGES
ARKOON Network Security http://www.arkoon.net
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