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Commit 5226b791 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
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cxgb4: get rid of custom busy poll code 



In linux-4.5, busy polling was implemented in core
NAPI stack, meaning that all custom implementation can
be removed from drivers.

Not only we remove lot of code, we also remove one spin_lock()
from driver fast path.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 362108b5

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

+0 −113
Original line number Diff line number Diff line
@@ -586,22 +586,6 @@ struct sge_rspq { /* state for an SGE response queue */ 
	rspq_handler_t handler;

	rspq_flush_handler_t flush_handler;

	struct t4_lro_mgr lro_mgr;

#ifdef CONFIG_NET_RX_BUSY_POLL

#define CXGB_POLL_STATE_IDLE		0

#define CXGB_POLL_STATE_NAPI		BIT(0) /* NAPI owns this poll */

#define CXGB_POLL_STATE_POLL		BIT(1) /* poll owns this poll */

#define CXGB_POLL_STATE_NAPI_YIELD	BIT(2) /* NAPI yielded this poll */

#define CXGB_POLL_STATE_POLL_YIELD	BIT(3) /* poll yielded this poll */

#define CXGB_POLL_YIELD			(CXGB_POLL_STATE_NAPI_YIELD |   \

					 CXGB_POLL_STATE_POLL_YIELD)

#define CXGB_POLL_LOCKED		(CXGB_POLL_STATE_NAPI |         \

					 CXGB_POLL_STATE_POLL)

#define CXGB_POLL_USER_PEND		(CXGB_POLL_STATE_POLL |         \

					 CXGB_POLL_STATE_POLL_YIELD)

	unsigned int bpoll_state;

	spinlock_t bpoll_lock;		/* lock for busy poll */

#endif /* CONFIG_NET_RX_BUSY_POLL */



};



struct sge_eth_stats {              /* Ethernet queue statistics */
@@ -1173,102 +1157,6 @@ static inline struct adapter *netdev2adap(const struct net_device *dev) 
	return netdev2pinfo(dev)->adapter;

}



#ifdef CONFIG_NET_RX_BUSY_POLL

static inline void cxgb_busy_poll_init_lock(struct sge_rspq *q)

{

	spin_lock_init(&q->bpoll_lock);

	q->bpoll_state = CXGB_POLL_STATE_IDLE;

}



static inline bool cxgb_poll_lock_napi(struct sge_rspq *q)

{

	bool rc = true;



	spin_lock(&q->bpoll_lock);

	if (q->bpoll_state & CXGB_POLL_LOCKED) {

		q->bpoll_state |= CXGB_POLL_STATE_NAPI_YIELD;

		rc = false;

	} else {

		q->bpoll_state = CXGB_POLL_STATE_NAPI;

	}

	spin_unlock(&q->bpoll_lock);

	return rc;

}



static inline bool cxgb_poll_unlock_napi(struct sge_rspq *q)

{

	bool rc = false;



	spin_lock(&q->bpoll_lock);

	if (q->bpoll_state & CXGB_POLL_STATE_POLL_YIELD)

		rc = true;

	q->bpoll_state = CXGB_POLL_STATE_IDLE;

	spin_unlock(&q->bpoll_lock);

	return rc;

}



static inline bool cxgb_poll_lock_poll(struct sge_rspq *q)

{

	bool rc = true;



	spin_lock_bh(&q->bpoll_lock);

	if (q->bpoll_state & CXGB_POLL_LOCKED) {

		q->bpoll_state |= CXGB_POLL_STATE_POLL_YIELD;

		rc = false;

	} else {

		q->bpoll_state |= CXGB_POLL_STATE_POLL;

	}

	spin_unlock_bh(&q->bpoll_lock);

	return rc;

}



static inline bool cxgb_poll_unlock_poll(struct sge_rspq *q)

{

	bool rc = false;



	spin_lock_bh(&q->bpoll_lock);

	if (q->bpoll_state & CXGB_POLL_STATE_POLL_YIELD)

		rc = true;

	q->bpoll_state = CXGB_POLL_STATE_IDLE;

	spin_unlock_bh(&q->bpoll_lock);

	return rc;

}



static inline bool cxgb_poll_busy_polling(struct sge_rspq *q)

{

	return q->bpoll_state & CXGB_POLL_USER_PEND;

}

#else

static inline void cxgb_busy_poll_init_lock(struct sge_rspq *q)

{

}



static inline bool cxgb_poll_lock_napi(struct sge_rspq *q)

{

	return true;

}



static inline bool cxgb_poll_unlock_napi(struct sge_rspq *q)

{

	return false;

}



static inline bool cxgb_poll_lock_poll(struct sge_rspq *q)

{

	return false;

}



static inline bool cxgb_poll_unlock_poll(struct sge_rspq *q)

{

	return false;

}



static inline bool cxgb_poll_busy_polling(struct sge_rspq *q)

{

	return false;

}

#endif /* CONFIG_NET_RX_BUSY_POLL */



/* Return a version number to identify the type of adapter.  The scheme is:

 * - bits 0..9: chip version

 * - bits 10..15: chip revision
@@ -1325,7 +1213,6 @@ irqreturn_t t4_sge_intr_msix(int irq, void *cookie); 
int t4_sge_init(struct adapter *adap);

void t4_sge_start(struct adapter *adap);

void t4_sge_stop(struct adapter *adap);

int cxgb_busy_poll(struct napi_struct *napi);

void cxgb4_set_ethtool_ops(struct net_device *netdev);

int cxgb4_write_rss(const struct port_info *pi, const u16 *queues);

extern int dbfifo_int_thresh;

drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c

+3 −13
Original line number Diff line number Diff line
@@ -744,14 +744,8 @@ static void quiesce_rx(struct adapter *adap) 
	for (i = 0; i < adap->sge.ingr_sz; i++) {

		struct sge_rspq *q = adap->sge.ingr_map[i];



		if (q && q->handler) {

		if (q && q->handler)

			napi_disable(&q->napi);

			local_bh_disable();

			while (!cxgb_poll_lock_napi(q))

				mdelay(1);

			local_bh_enable();

		}



	}

}
@@ -782,10 +776,9 @@ static void enable_rx(struct adapter *adap) 


		if (!q)

			continue;

		if (q->handler) {

			cxgb_busy_poll_init_lock(q);

		if (q->handler)

			napi_enable(&q->napi);

		}



		/* 0-increment GTS to start the timer and enable interrupts */

		t4_write_reg(adap, MYPF_REG(SGE_PF_GTS_A),

			     SEINTARM_V(q->intr_params) |
@@ -2763,9 +2756,6 @@ static const struct net_device_ops cxgb4_netdev_ops = { 
	.ndo_fcoe_enable      = cxgb_fcoe_enable,

	.ndo_fcoe_disable     = cxgb_fcoe_disable,

#endif /* CONFIG_CHELSIO_T4_FCOE */

#ifdef CONFIG_NET_RX_BUSY_POLL

	.ndo_busy_poll        = cxgb_busy_poll,

#endif

	.ndo_set_tx_maxrate   = cxgb_set_tx_maxrate,

	.ndo_setup_tc         = cxgb_setup_tc,

};

drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c

+3 −9
Original line number Diff line number Diff line
@@ -408,10 +408,9 @@ static void enable_rx(struct adapter *adap, struct sge_rspq *q) 
	if (!q)

		return;



	if (q->handler) {

		cxgb_busy_poll_init_lock(q);

	if (q->handler)

		napi_enable(&q->napi);

	}



	/* 0-increment GTS to start the timer and enable interrupts */

	t4_write_reg(adap, MYPF_REG(SGE_PF_GTS_A),

		     SEINTARM_V(q->intr_params) |
@@ -420,13 +419,8 @@ static void enable_rx(struct adapter *adap, struct sge_rspq *q) 


static void quiesce_rx(struct adapter *adap, struct sge_rspq *q)

{

	if (q && q->handler) {

	if (q && q->handler)

		napi_disable(&q->napi);

		local_bh_disable();

		while (!cxgb_poll_lock_napi(q))

			mdelay(1);

		local_bh_enable();

	}

}



static void enable_rx_uld(struct adapter *adap, unsigned int uld_type)

drivers/net/ethernet/chelsio/cxgb4/sge.c

+0 −39
Original line number Diff line number Diff line
@@ -43,9 +43,7 @@ 
#include <linux/export.h>

#include <net/ipv6.h>

#include <net/tcp.h>

#ifdef CONFIG_NET_RX_BUSY_POLL

#include <net/busy_poll.h>

#endif /* CONFIG_NET_RX_BUSY_POLL */

#ifdef CONFIG_CHELSIO_T4_FCOE

#include <scsi/fc/fc_fcoe.h>

#endif /* CONFIG_CHELSIO_T4_FCOE */
@@ -2059,7 +2057,6 @@ int t4_ethrx_handler(struct sge_rspq *q, const __be64 *rsp, 
	csum_ok = pkt->csum_calc && !err_vec &&

		  (q->netdev->features & NETIF_F_RXCSUM);

	if ((pkt->l2info & htonl(RXF_TCP_F)) &&

	    !(cxgb_poll_busy_polling(q)) &&

	    (q->netdev->features & NETIF_F_GRO) && csum_ok && !pkt->ip_frag) {

		do_gro(rxq, si, pkt);

		return 0;
@@ -2290,38 +2287,6 @@ static int process_responses(struct sge_rspq *q, int budget) 
	return budget - budget_left;

}



#ifdef CONFIG_NET_RX_BUSY_POLL

int cxgb_busy_poll(struct napi_struct *napi)

{

	struct sge_rspq *q = container_of(napi, struct sge_rspq, napi);

	unsigned int params, work_done;

	u32 val;



	if (!cxgb_poll_lock_poll(q))

		return LL_FLUSH_BUSY;



	work_done = process_responses(q, 4);

	params = QINTR_TIMER_IDX_V(TIMERREG_COUNTER0_X) | QINTR_CNT_EN_V(1);

	q->next_intr_params = params;

	val = CIDXINC_V(work_done) | SEINTARM_V(params);



	/* If we don't have access to the new User GTS (T5+), use the old

	 * doorbell mechanism; otherwise use the new BAR2 mechanism.

	 */

	if (unlikely(!q->bar2_addr))

		t4_write_reg(q->adap, MYPF_REG(SGE_PF_GTS_A),

			     val | INGRESSQID_V((u32)q->cntxt_id));

	else {

		writel(val | INGRESSQID_V(q->bar2_qid),

		       q->bar2_addr + SGE_UDB_GTS);

		wmb();

	}



	cxgb_poll_unlock_poll(q);

	return work_done;

}

#endif /* CONFIG_NET_RX_BUSY_POLL */



/**

 *	napi_rx_handler - the NAPI handler for Rx processing

 *	@napi: the napi instance
@@ -2340,9 +2305,6 @@ static int napi_rx_handler(struct napi_struct *napi, int budget) 
	int work_done;

	u32 val;



	if (!cxgb_poll_lock_napi(q))

		return budget;



	work_done = process_responses(q, budget);

	if (likely(work_done < budget)) {

		int timer_index;
@@ -2382,7 +2344,6 @@ static int napi_rx_handler(struct napi_struct *napi, int budget) 
		       q->bar2_addr + SGE_UDB_GTS);

		wmb();

	}

	cxgb_poll_unlock_napi(q);

	return work_done;

}