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Commit 362108b5 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

myri10ge: get rid of custom busy poll code 



Compared to custom busy_poll, the generic NAPI one is simpler and
removes a lot of code. It removes one atomic in the fast path (when
busy poll is not in action) since we do not have to use an extra
spinlock.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fb6113e6

drivers/net/ethernet/myricom/myri10ge/myri10ge.c

+4 −193
Original line number Diff line number Diff line
@@ -191,21 +191,6 @@ struct myri10ge_slice_state { 
	int cpu;

	__be32 __iomem *dca_tag;

#endif

#ifdef CONFIG_NET_RX_BUSY_POLL

	unsigned int state;

#define SLICE_STATE_IDLE	0

#define SLICE_STATE_NAPI	1	/* NAPI owns this slice */

#define SLICE_STATE_POLL	2	/* poll owns this slice */

#define SLICE_LOCKED (SLICE_STATE_NAPI | SLICE_STATE_POLL)

#define SLICE_STATE_NAPI_YIELD	4	/* NAPI yielded this slice */

#define SLICE_STATE_POLL_YIELD	8	/* poll yielded this slice */

#define SLICE_USER_PEND (SLICE_STATE_POLL | SLICE_STATE_POLL_YIELD)

	spinlock_t lock;

	unsigned long lock_napi_yield;

	unsigned long lock_poll_yield;

	unsigned long busy_poll_miss;

	unsigned long busy_poll_cnt;

#endif /* CONFIG_NET_RX_BUSY_POLL */

	char irq_desc[32];

};
@@ -925,92 +910,6 @@ static int myri10ge_dma_test(struct myri10ge_priv *mgp, int test_type) 
	return status;

}



#ifdef CONFIG_NET_RX_BUSY_POLL

static inline void myri10ge_ss_init_lock(struct myri10ge_slice_state *ss)

{

	spin_lock_init(&ss->lock);

	ss->state = SLICE_STATE_IDLE;

}



static inline bool myri10ge_ss_lock_napi(struct myri10ge_slice_state *ss)

{

	bool rc = true;

	spin_lock(&ss->lock);

	if ((ss->state & SLICE_LOCKED)) {

		WARN_ON((ss->state & SLICE_STATE_NAPI));

		ss->state |= SLICE_STATE_NAPI_YIELD;

		rc = false;

		ss->lock_napi_yield++;

	} else

		ss->state = SLICE_STATE_NAPI;

	spin_unlock(&ss->lock);

	return rc;

}



static inline void myri10ge_ss_unlock_napi(struct myri10ge_slice_state *ss)

{

	spin_lock(&ss->lock);

	WARN_ON((ss->state & (SLICE_STATE_POLL | SLICE_STATE_NAPI_YIELD)));

	ss->state = SLICE_STATE_IDLE;

	spin_unlock(&ss->lock);

}



static inline bool myri10ge_ss_lock_poll(struct myri10ge_slice_state *ss)

{

	bool rc = true;

	spin_lock_bh(&ss->lock);

	if ((ss->state & SLICE_LOCKED)) {

		ss->state |= SLICE_STATE_POLL_YIELD;

		rc = false;

		ss->lock_poll_yield++;

	} else

		ss->state |= SLICE_STATE_POLL;

	spin_unlock_bh(&ss->lock);

	return rc;

}



static inline void myri10ge_ss_unlock_poll(struct myri10ge_slice_state *ss)

{

	spin_lock_bh(&ss->lock);

	WARN_ON((ss->state & SLICE_STATE_NAPI));

	ss->state = SLICE_STATE_IDLE;

	spin_unlock_bh(&ss->lock);

}



static inline bool myri10ge_ss_busy_polling(struct myri10ge_slice_state *ss)

{

	WARN_ON(!(ss->state & SLICE_LOCKED));

	return (ss->state & SLICE_USER_PEND);

}

#else /* CONFIG_NET_RX_BUSY_POLL */

static inline void myri10ge_ss_init_lock(struct myri10ge_slice_state *ss)

{

}



static inline bool myri10ge_ss_lock_napi(struct myri10ge_slice_state *ss)

{

	return false;

}



static inline void myri10ge_ss_unlock_napi(struct myri10ge_slice_state *ss)

{

}



static inline bool myri10ge_ss_lock_poll(struct myri10ge_slice_state *ss)

{

	return false;

}



static inline void myri10ge_ss_unlock_poll(struct myri10ge_slice_state *ss)

{

}



static inline bool myri10ge_ss_busy_polling(struct myri10ge_slice_state *ss)

{

	return false;

}

#endif



static int myri10ge_reset(struct myri10ge_priv *mgp)

{

	struct myri10ge_cmd cmd;
@@ -1426,7 +1325,6 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum) 
	struct pci_dev *pdev = mgp->pdev;

	struct net_device *dev = mgp->dev;

	u8 *va;

	bool polling;



	if (len <= mgp->small_bytes) {

		rx = &ss->rx_small;
@@ -1441,14 +1339,6 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum) 
	va = page_address(rx->info[idx].page) + rx->info[idx].page_offset;

	prefetch(va);



	/* When busy polling in user context, allocate skb and copy headers to

	 * skb's linear memory ourselves.  When not busy polling, use the napi

	 * gro api.

	 */

	polling = myri10ge_ss_busy_polling(ss);

	if (polling)

		skb = netdev_alloc_skb(dev, MYRI10GE_HLEN + 16);

	else

	skb = napi_get_frags(&ss->napi);

	if (unlikely(skb == NULL)) {

		ss->stats.rx_dropped++;
@@ -1489,26 +1379,6 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum) 
	myri10ge_vlan_rx(mgp->dev, va, skb);

	skb_record_rx_queue(skb, ss - &mgp->ss[0]);



	if (polling) {

		int hlen;



		/* myri10ge_vlan_rx might have moved the header, so compute

		 * length and address again.

		 */

		hlen = MYRI10GE_HLEN > skb->len ? skb->len : MYRI10GE_HLEN;

		va = page_address(skb_frag_page(&rx_frags[0])) +

			rx_frags[0].page_offset;

		/* Copy header into the skb linear memory */

		skb_copy_to_linear_data(skb, va, hlen);

		rx_frags[0].page_offset += hlen;

		rx_frags[0].size -= hlen;

		skb->data_len -= hlen;

		skb->tail += hlen;

		skb->protocol = eth_type_trans(skb, dev);

		skb_mark_napi_id(skb, &ss->napi);

		netif_receive_skb(skb);

	}

	else

	napi_gro_frags(&ss->napi);



	return 1;
@@ -1669,14 +1539,9 @@ static int myri10ge_poll(struct napi_struct *napi, int budget) 
	if (ss->mgp->dca_enabled)

		myri10ge_update_dca(ss);

#endif

	/* Try later if the busy_poll handler is running. */

	if (!myri10ge_ss_lock_napi(ss))

		return budget;



	/* process as many rx events as NAPI will allow */

	work_done = myri10ge_clean_rx_done(ss, budget);



	myri10ge_ss_unlock_napi(ss);

	if (work_done < budget) {

		napi_complete_done(napi, work_done);

		put_be32(htonl(3), ss->irq_claim);
@@ -1684,34 +1549,6 @@ static int myri10ge_poll(struct napi_struct *napi, int budget) 
	return work_done;

}



#ifdef CONFIG_NET_RX_BUSY_POLL

static int myri10ge_busy_poll(struct napi_struct *napi)

{

	struct myri10ge_slice_state *ss =

	    container_of(napi, struct myri10ge_slice_state, napi);

	struct myri10ge_priv *mgp = ss->mgp;

	int work_done;



	/* Poll only when the link is up */

	if (mgp->link_state != MXGEFW_LINK_UP)

		return LL_FLUSH_FAILED;



	if (!myri10ge_ss_lock_poll(ss))

		return LL_FLUSH_BUSY;



	/* Process a small number of packets */

	work_done = myri10ge_clean_rx_done(ss, 4);

	if (work_done)

		ss->busy_poll_cnt += work_done;

	else

		ss->busy_poll_miss++;



	myri10ge_ss_unlock_poll(ss);



	return work_done;

}

#endif /* CONFIG_NET_RX_BUSY_POLL */



static irqreturn_t myri10ge_intr(int irq, void *arg)

{

	struct myri10ge_slice_state *ss = arg;
@@ -1919,10 +1756,6 @@ static const char myri10ge_gstrings_slice_stats[][ETH_GSTRING_LEN] = { 
	"tx_pkt_start", "tx_pkt_done", "tx_req", "tx_done",

	"rx_small_cnt", "rx_big_cnt",

	"wake_queue", "stop_queue", "tx_linearized",

#ifdef CONFIG_NET_RX_BUSY_POLL

	"rx_lock_napi_yield", "rx_lock_poll_yield", "rx_busy_poll_miss",

	"rx_busy_poll_cnt",

#endif

};



#define MYRI10GE_NET_STATS_LEN      21
@@ -2022,12 +1855,6 @@ myri10ge_get_ethtool_stats(struct net_device *netdev, 
		data[i++] = (unsigned int)ss->tx.wake_queue;

		data[i++] = (unsigned int)ss->tx.stop_queue;

		data[i++] = (unsigned int)ss->tx.linearized;

#ifdef CONFIG_NET_RX_BUSY_POLL

		data[i++] = ss->lock_napi_yield;

		data[i++] = ss->lock_poll_yield;

		data[i++] = ss->busy_poll_miss;

		data[i++] = ss->busy_poll_cnt;

#endif

	}

}
@@ -2589,9 +2416,6 @@ static int myri10ge_open(struct net_device *dev) 
			goto abort_with_rings;

		}



		/* Initialize the slice spinlock and state used for polling */

		myri10ge_ss_init_lock(ss);



		/* must happen prior to any irq */

		napi_enable(&(ss)->napi);

	}
@@ -2668,19 +2492,9 @@ static int myri10ge_close(struct net_device *dev) 


	del_timer_sync(&mgp->watchdog_timer);

	mgp->running = MYRI10GE_ETH_STOPPING;

	for (i = 0; i < mgp->num_slices; i++) {

	for (i = 0; i < mgp->num_slices; i++)

		napi_disable(&mgp->ss[i].napi);

		local_bh_disable(); /* myri10ge_ss_lock_napi needs this */

		/* Lock the slice to prevent the busy_poll handler from

		 * accessing it.  Later when we bring the NIC up, myri10ge_open

		 * resets the slice including this lock.

		 */

		while (!myri10ge_ss_lock_napi(&mgp->ss[i])) {

			pr_info("Slice %d locked\n", i);

			mdelay(1);

		}

		local_bh_enable();

	}



	netif_carrier_off(dev);



	netif_tx_stop_all_queues(dev);
@@ -3953,9 +3767,6 @@ static const struct net_device_ops myri10ge_netdev_ops = { 
	.ndo_change_mtu		= myri10ge_change_mtu,

	.ndo_set_rx_mode	= myri10ge_set_multicast_list,

	.ndo_set_mac_address	= myri10ge_set_mac_address,

#ifdef CONFIG_NET_RX_BUSY_POLL

	.ndo_busy_poll		= myri10ge_busy_poll,

#endif

};



static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent)