Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e092be60 authored by Ayyappan Veeraiyan's avatar Ayyappan Veeraiyan Committed by Jeff Garzik
Browse files

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: default avatarAyyappan Veeraiyan <ayyappan.veeraiyan@intel.com>
Signed-off-by: default avatarAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent d4f80882

drivers/net/ixgbe/ixgbe.h

+0 −2
Original line number Diff line number Diff line
@@ -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;

drivers/net/ixgbe/ixgbe_main.c

+76 −34
Original line number Diff line number Diff line
@@ -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))

#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);



	spin_unlock(&tx_ring->tx_lock);

			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;

}