From e092be60b2292af91c55f085151d58dc8a76820a Mon Sep 17 00:00:00 2001 From: Ayyappan Veeraiyan Date: Fri, 1 Feb 2008 15:58:49 -0800 Subject: ixbge: remove TX lock and redo TX accounting. This ports Herbert Xu's "maybe_stop_tx" code and removes the tx_lock which is not needed. Signed-off-by: Ayyappan Veeraiyan Signed-off-by: Auke Kok Signed-off-by: Jeff Garzik --- drivers/net/ixgbe/ixgbe.h | 2 - drivers/net/ixgbe/ixgbe_main.c | 110 ++++++++++++++++++++++++++++------------- 2 files changed, 76 insertions(+), 36 deletions(-) (limited to 'drivers/net/ixgbe') diff --git a/drivers/net/ixgbe/ixgbe.h b/drivers/net/ixgbe/ixgbe.h index 7dd9a03650d3..d0bf206632ca 100644 --- a/drivers/net/ixgbe/ixgbe.h +++ b/drivers/net/ixgbe/ixgbe.h @@ -136,8 +136,6 @@ struct ixgbe_ring { u16 head; u16 tail; - /* To protect race between sender and clean_tx_irq */ - spinlock_t tx_lock; struct ixgbe_queue_stats stats; diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c index 28bb20330de7..b4c9c77c09dd 100644 --- a/drivers/net/ixgbe/ixgbe_main.c +++ b/drivers/net/ixgbe/ixgbe_main.c @@ -165,6 +165,15 @@ static inline bool ixgbe_check_tx_hang(struct ixgbe_adapter *adapter, return false; } +#define IXGBE_MAX_TXD_PWR 14 +#define IXGBE_MAX_DATA_PER_TXD (1 << IXGBE_MAX_TXD_PWR) + +/* Tx Descriptors needed, worst case */ +#define TXD_USE_COUNT(S) (((S) >> IXGBE_MAX_TXD_PWR) + \ + (((S) & (IXGBE_MAX_DATA_PER_TXD - 1)) ? 1 : 0)) +#define DESC_NEEDED (TXD_USE_COUNT(IXGBE_MAX_DATA_PER_TXD) /* skb->data */ + \ + MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE) + 1) /* for context */ + /** * ixgbe_clean_tx_irq - Reclaim resources after transmit completes * @adapter: board private structure @@ -177,18 +186,34 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_adapter *adapter, struct ixgbe_tx_buffer *tx_buffer_info; unsigned int i, eop; bool cleaned = false; - int count = 0; + unsigned int total_tx_bytes = 0, total_tx_packets = 0; i = tx_ring->next_to_clean; eop = tx_ring->tx_buffer_info[i].next_to_watch; eop_desc = IXGBE_TX_DESC_ADV(*tx_ring, eop); while (eop_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)) { - for (cleaned = false; !cleaned;) { + cleaned = false; + while (!cleaned) { tx_desc = IXGBE_TX_DESC_ADV(*tx_ring, i); tx_buffer_info = &tx_ring->tx_buffer_info[i]; cleaned = (i == eop); tx_ring->stats.bytes += tx_buffer_info->length; + if (cleaned) { + struct sk_buff *skb = tx_buffer_info->skb; +#ifdef NETIF_F_TSO + unsigned int segs, bytecount; + segs = skb_shinfo(skb)->gso_segs ?: 1; + /* multiply data chunks by size of headers */ + bytecount = ((segs - 1) * skb_headlen(skb)) + + skb->len; + total_tx_packets += segs; + total_tx_bytes += bytecount; +#else + total_tx_packets++; + total_tx_bytes += skb->len; +#endif + } ixgbe_unmap_and_free_tx_resource(adapter, tx_buffer_info); tx_desc->wb.status = 0; @@ -204,29 +229,34 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_adapter *adapter, eop_desc = IXGBE_TX_DESC_ADV(*tx_ring, eop); /* weight of a sort for tx, avoid endless transmit cleanup */ - if (count++ >= tx_ring->work_limit) + if (total_tx_packets >= tx_ring->work_limit) break; } tx_ring->next_to_clean = i; -#define TX_WAKE_THRESHOLD 32 - spin_lock(&tx_ring->tx_lock); - - if (cleaned && netif_carrier_ok(netdev) && - (IXGBE_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD) && - !test_bit(__IXGBE_DOWN, &adapter->state)) - netif_wake_queue(netdev); - - spin_unlock(&tx_ring->tx_lock); +#define TX_WAKE_THRESHOLD (DESC_NEEDED * 2) + if (total_tx_packets && netif_carrier_ok(netdev) && + (IXGBE_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD)) { + /* Make sure that anybody stopping the queue after this + * sees the new next_to_clean. + */ + smp_mb(); + if (netif_queue_stopped(netdev) && + !test_bit(__IXGBE_DOWN, &adapter->state)) { + netif_wake_queue(netdev); + adapter->restart_queue++; + } + } if (adapter->detect_tx_hung) if (ixgbe_check_tx_hang(adapter, tx_ring, eop, eop_desc)) netif_stop_queue(netdev); - if (count >= tx_ring->work_limit) + if (total_tx_packets >= tx_ring->work_limit) IXGBE_WRITE_REG(&adapter->hw, IXGBE_EICS, tx_ring->eims_value); + cleaned = total_tx_packets ? true : false; return cleaned; } @@ -1646,7 +1676,6 @@ int ixgbe_setup_tx_resources(struct ixgbe_adapter *adapter, txdr->next_to_use = 0; txdr->next_to_clean = 0; txdr->work_limit = txdr->count; - spin_lock_init(&txdr->tx_lock); return 0; } @@ -2086,15 +2115,6 @@ static void ixgbe_watchdog(unsigned long data) round_jiffies(jiffies + 2 * HZ)); } -#define IXGBE_MAX_TXD_PWR 14 -#define IXGBE_MAX_DATA_PER_TXD (1 << IXGBE_MAX_TXD_PWR) - -/* Tx Descriptors needed, worst case */ -#define TXD_USE_COUNT(S) (((S) >> IXGBE_MAX_TXD_PWR) + \ - (((S) & (IXGBE_MAX_DATA_PER_TXD - 1)) ? 1 : 0)) -#define DESC_NEEDED (TXD_USE_COUNT(IXGBE_MAX_DATA_PER_TXD) /* skb->data */ + \ - MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE) + 1) /* for context */ - static int ixgbe_tso(struct ixgbe_adapter *adapter, struct ixgbe_ring *tx_ring, struct sk_buff *skb, u32 tx_flags, u8 *hdr_len) @@ -2366,6 +2386,37 @@ static void ixgbe_tx_queue(struct ixgbe_adapter *adapter, writel(i, adapter->hw.hw_addr + tx_ring->tail); } +static int __ixgbe_maybe_stop_tx(struct net_device *netdev, + struct ixgbe_ring *tx_ring, int size) +{ + struct ixgbe_adapter *adapter = netdev_priv(netdev); + + netif_stop_queue(netdev); + /* Herbert's original patch had: + * smp_mb__after_netif_stop_queue(); + * but since that doesn't exist yet, just open code it. */ + smp_mb(); + + /* We need to check again in a case another CPU has just + * made room available. */ + if (likely(IXGBE_DESC_UNUSED(tx_ring) < size)) + return -EBUSY; + + /* A reprieve! - use start_queue because it doesn't call schedule */ + netif_wake_queue(netdev); + ++adapter->restart_queue; + return 0; +} + +static int ixgbe_maybe_stop_tx(struct net_device *netdev, + struct ixgbe_ring *tx_ring, int size) +{ + if (likely(IXGBE_DESC_UNUSED(tx_ring) >= size)) + return 0; + return __ixgbe_maybe_stop_tx(netdev, tx_ring, size); +} + + static int ixgbe_xmit_frame(struct sk_buff *skb, struct net_device *netdev) { struct ixgbe_adapter *adapter = netdev_priv(netdev); @@ -2373,7 +2424,6 @@ static int ixgbe_xmit_frame(struct sk_buff *skb, struct net_device *netdev) unsigned int len = skb->len; unsigned int first; unsigned int tx_flags = 0; - unsigned long flags = 0; u8 hdr_len; int tso; unsigned int mss = 0; @@ -2399,14 +2449,10 @@ static int ixgbe_xmit_frame(struct sk_buff *skb, struct net_device *netdev) for (f = 0; f < nr_frags; f++) count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size); - spin_lock_irqsave(&tx_ring->tx_lock, flags); - if (IXGBE_DESC_UNUSED(tx_ring) < (count + 2)) { + if (ixgbe_maybe_stop_tx(netdev, tx_ring, count)) { adapter->tx_busy++; - netif_stop_queue(netdev); - spin_unlock_irqrestore(&tx_ring->tx_lock, flags); return NETDEV_TX_BUSY; } - spin_unlock_irqrestore(&tx_ring->tx_lock, flags); if (adapter->vlgrp && vlan_tx_tag_present(skb)) { tx_flags |= IXGBE_TX_FLAGS_VLAN; tx_flags |= (vlan_tx_tag_get(skb) << IXGBE_TX_FLAGS_VLAN_SHIFT); @@ -2433,11 +2479,7 @@ static int ixgbe_xmit_frame(struct sk_buff *skb, struct net_device *netdev) netdev->trans_start = jiffies; - spin_lock_irqsave(&tx_ring->tx_lock, flags); - /* Make sure there is space in the ring for the next send. */ - if (IXGBE_DESC_UNUSED(tx_ring) < DESC_NEEDED) - netif_stop_queue(netdev); - spin_unlock_irqrestore(&tx_ring->tx_lock, flags); + ixgbe_maybe_stop_tx(netdev, tx_ring, DESC_NEEDED); return NETDEV_TX_OK; } -- cgit v1.2.2