My preference would be for drivers not to use LLTX (except loopback) and just
use the dev->xmit_lock via netif_tx_lock if possible. Something like this for
e1000.
Subject: [PATCH] e1000 no lltx
Get rid of lockless transmit for e1000. Use netif_tx_lock instead
of having to do locking in device. For NAPI this is trivial but
for the non-NAPI case it means scheduling a tasklet to do Tx
cleanup
Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>
---
drivers/net/e1000/e1000.h | 7 +++--
drivers/net/e1000/e1000_main.c | 53 ++++++++++++++++++++++------------------
2 files changed, 33 insertions(+), 27 deletions(-)
87a7c62864818350ebb7da73f26e1dc49c5eb2e5
diff --git a/drivers/net/e1000/e1000.h b/drivers/net/e1000/e1000.h
index 98afa9c..9de6519 100644
--- a/drivers/net/e1000/e1000.h
+++ b/drivers/net/e1000/e1000.h
@@ -190,7 +190,6 @@ struct e1000_tx_ring {
/* array of buffer information structs */
struct e1000_buffer *buffer_info;
- spinlock_t tx_lock;
uint16_t tdh;
uint16_t tdt;
boolean_t last_tx_tso;
@@ -251,9 +250,8 @@ struct e1000_adapter {
uint16_t link_speed;
uint16_t link_duplex;
spinlock_t stats_lock;
-#ifdef CONFIG_E1000_NAPI
spinlock_t tx_queue_lock;
-#endif
+
atomic_t irq_sem;
struct work_struct reset_task;
uint8_t fc_autoneg;
@@ -263,6 +261,9 @@ struct e1000_adapter {
/* TX */
struct e1000_tx_ring *tx_ring; /* One per active queue */
+#ifndef CONFIG_E1000_NAPI
+ struct tasklet_struct tx_tasklet;
+#endif
unsigned long tx_queue_len;
uint32_t txd_cmd;
uint32_t tx_int_delay;
diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index acf818b..8eb38a7 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -158,6 +158,7 @@ static boolean_t e1000_clean_rx_irq_ps(s
struct e1000_rx_ring *rx_ring,
int *work_done, int work_to_do);
#else
+static void e1000_tx_tasklet(unsigned long arg);
static boolean_t e1000_clean_rx_irq(struct e1000_adapter *adapter,
struct e1000_rx_ring *rx_ring);
static boolean_t e1000_clean_rx_irq_ps(struct e1000_adapter *adapter,
@@ -811,8 +812,6 @@ e1000_probe(struct pci_dev *pdev,
if (pci_using_dac)
netdev->features |= NETIF_F_HIGHDMA;
- netdev->features |= NETIF_F_LLTX;
-
adapter->en_mng_pt = e1000_enable_mng_pass_thru(&adapter->hw);
/* initialize eeprom parameters */
@@ -1155,8 +1154,11 @@ e1000_sw_init(struct e1000_adapter *adap
dev_hold(&adapter->polling_netdev[i]);
set_bit(__LINK_STATE_START, &adapter->polling_netdev[i].state);
}
- spin_lock_init(&adapter->tx_queue_lock);
+#else
+ adapter->tx_tasklet.func = &e1000_tx_tasklet;
+ adapter->tx_tasklet.data = (unsigned long) adapter;
#endif
+ spin_lock_init(&adapter->tx_queue_lock);
atomic_set(&adapter->irq_sem, 1);
spin_lock_init(&adapter->stats_lock);
@@ -1407,7 +1409,6 @@ setup_tx_desc_die:
txdr->next_to_use = 0;
txdr->next_to_clean = 0;
- spin_lock_init(&txdr->tx_lock);
return 0;
}
@@ -1991,6 +1992,23 @@ e1000_clean_tx_ring(struct e1000_adapter
writel(0, adapter->hw.hw_addr + tx_ring->tdt);
}
+#ifndef CONFIG_E1000_NAPI
+static void
+e1000_tx_tasklet(unsigned long arg)
+{
+ struct e1000_adapter *adapter = (struct e1000_adapter *) arg;
+ int i;
+
+ if (!spin_trylock(&adapter->tx_queue_lock))
+ return;
+
+ for (i = 0; i < adapter->num_tx_queues; i++)
+ e1000_clean_tx_irq(adapter, adapter->tx_ring);
+
+ spin_unlock(&adapter->tx_queue_lock);
+}
+#endif
+
/**
* e1000_clean_all_tx_rings - Free Tx Buffers for all queues
* @adapter: board private structure
@@ -2902,7 +2920,6 @@ e1000_xmit_frame(struct sk_buff *skb, st
unsigned int max_txd_pwr = E1000_MAX_TXD_PWR;
unsigned int tx_flags = 0;
unsigned int len = skb->len;
- unsigned long flags;
unsigned int nr_frags = 0;
unsigned int mss = 0;
int count = 0;
@@ -2996,18 +3013,10 @@ e1000_xmit_frame(struct sk_buff *skb, st
(adapter->hw.mac_type == e1000_82573))
e1000_transfer_dhcp_info(adapter, skb);
- local_irq_save(flags);
- if (!spin_trylock(&tx_ring->tx_lock)) {
- /* Collision - tell upper layer to requeue */
- local_irq_restore(flags);
- return NETDEV_TX_LOCKED;
- }
-
/* need: count + 2 desc gap to keep tail from touching
* head, otherwise try next time */
if (unlikely(E1000_DESC_UNUSED(tx_ring) < count + 2)) {
netif_stop_queue(netdev);
- spin_unlock_irqrestore(&tx_ring->tx_lock, flags);
return NETDEV_TX_BUSY;
}
@@ -3015,7 +3024,6 @@ e1000_xmit_frame(struct sk_buff *skb, st
if (unlikely(e1000_82547_fifo_workaround(adapter, skb))) {
netif_stop_queue(netdev);
mod_timer(&adapter->tx_fifo_stall_timer, jiffies);
- spin_unlock_irqrestore(&tx_ring->tx_lock, flags);
return NETDEV_TX_BUSY;
}
}
@@ -3030,7 +3038,6 @@ e1000_xmit_frame(struct sk_buff *skb, st
tso = e1000_tso(adapter, tx_ring, skb);
if (tso < 0) {
dev_kfree_skb_any(skb);
- spin_unlock_irqrestore(&tx_ring->tx_lock, flags);
return NETDEV_TX_OK;
}
@@ -3056,7 +3063,6 @@ e1000_xmit_frame(struct sk_buff *skb, st
if (unlikely(E1000_DESC_UNUSED(tx_ring) < MAX_SKB_FRAGS + 2))
netif_stop_queue(netdev);
- spin_unlock_irqrestore(&tx_ring->tx_lock, flags);
return NETDEV_TX_OK;
}
@@ -3438,10 +3444,11 @@ e1000_intr(int irq, void *data, struct p
}
for (i = 0; i < E1000_MAX_INTR; i++)
- if (unlikely(!adapter->clean_rx(adapter, adapter->rx_ring) &
- !e1000_clean_tx_irq(adapter, adapter->tx_ring)))
+ if (!adapter->clean_rx(adapter, adapter->rx_ring))
break;
+ tasklet_schedule(&adapter->tx_tasklet);
+
if (hw->mac_type == e1000_82547 || hw->mac_type == e1000_82547_rev_2)
e1000_irq_enable(adapter);
@@ -3546,13 +3553,11 @@ e1000_clean_tx_irq(struct e1000_adapter
tx_ring->next_to_clean = i;
#define TX_WAKE_THRESHOLD 32
- if (unlikely(cleaned && netif_queue_stopped(netdev) &&
- netif_carrier_ok(netdev))) {
- spin_lock(&tx_ring->tx_lock);
- if (netif_queue_stopped(netdev) &&
- (E1000_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))
+ if (unlikely(cleaned && netif_carrier_ok(netdev))) {
+ netif_tx_lock(netdev);
+ if (E1000_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD)
netif_wake_queue(netdev);
- spin_unlock(&tx_ring->tx_lock);
+ netif_tx_unlock(netdev);
}
if (adapter->detect_tx_hung) {
--
1.1.3
-
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