[mirror_ubuntu-bionic-kernel.git] / include / net / busy_poll.h

/*
 * net busy poll support
 * Copyright(c) 2013 Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Author: Eliezer Tamir
 *
 * Contact Information:
 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
 */

#ifndef _LINUX_NET_BUSY_POLL_H
#define _LINUX_NET_BUSY_POLL_H

#include <linux/netdevice.h>
#include <linux/sched/clock.h>
#include <linux/sched/signal.h>
#include <net/ip.h>

/*		0 - Reserved to indicate value not set
 *     1..NR_CPUS - Reserved for sender_cpu
 *  NR_CPUS+1..~0 - Region available for NAPI IDs
 */
#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))

#ifdef CONFIG_NET_RX_BUSY_POLL

struct napi_struct;
extern unsigned int sysctl_net_busy_read __read_mostly;
extern unsigned int sysctl_net_busy_poll __read_mostly;

static inline bool net_busy_loop_on(void)
{
	return sysctl_net_busy_poll;
}

static inline bool sk_can_busy_loop(const struct sock *sk)
{
	return sk->sk_ll_usec && !signal_pending(current);
}

bool sk_busy_loop_end(void *p, unsigned long start_time);

void napi_busy_loop(unsigned int napi_id,
		    bool (*loop_end)(void *, unsigned long),
		    void *loop_end_arg);

#else /* CONFIG_NET_RX_BUSY_POLL */
static inline unsigned long net_busy_loop_on(void)
{
	return 0;
}

static inline bool sk_can_busy_loop(struct sock *sk)
{
	return false;
}

#endif /* CONFIG_NET_RX_BUSY_POLL */

static inline unsigned long busy_loop_current_time(void)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
	return (unsigned long)(local_clock() >> 10);
#else
	return 0;
#endif
}

/* in poll/select we use the global sysctl_net_ll_poll value */
static inline bool busy_loop_timeout(unsigned long start_time)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
	unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll);

	if (bp_usec) {
		unsigned long end_time = start_time + bp_usec;
		unsigned long now = busy_loop_current_time();

		return time_after(now, end_time);
	}
#endif
	return true;
}

static inline bool sk_busy_loop_timeout(struct sock *sk,
					unsigned long start_time)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
	unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec);

	if (bp_usec) {
		unsigned long end_time = start_time + bp_usec;
		unsigned long now = busy_loop_current_time();

		return time_after(now, end_time);
	}
#endif
	return true;
}

static inline void sk_busy_loop(struct sock *sk, int nonblock)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
	unsigned int napi_id = READ_ONCE(sk->sk_napi_id);

	if (napi_id >= MIN_NAPI_ID)
		napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk);
#endif
}

/* used in the NIC receive handler to mark the skb */
static inline void skb_mark_napi_id(struct sk_buff *skb,
				    struct napi_struct *napi)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
	skb->napi_id = napi->napi_id;
#endif
}

/* used in the protocol hanlder to propagate the napi_id to the socket */
static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
	WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
#endif
}

/* variant used for unconnected sockets */
static inline void sk_mark_napi_id_once(struct sock *sk,
					const struct sk_buff *skb)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
	if (!READ_ONCE(sk->sk_napi_id))
		WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
#endif
}

#endif /* _LINUX_NET_BUSY_POLL_H */
Commit	Line	Data
06021292	1	/*
8b80cda5	2	* net busy poll support
06021292 ET	3	* Copyright(c) 2013 Intel Corporation.
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms and conditions of the GNU General Public License,
	7	* version 2, as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along with
	15	* this program; if not, write to the Free Software Foundation, Inc.,
	16	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	17	*
	18	* Author: Eliezer Tamir
	19	*
	20	* Contact Information:
	21	* e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
	22	*/
	23
8b80cda5 ET	24	#ifndef _LINUX_NET_BUSY_POLL_H
8b80cda5 ET	25	#define _LINUX_NET_BUSY_POLL_H
06021292 ET	26
06021292 ET	27	#include <linux/netdevice.h>
e6017571	28	#include <linux/sched/clock.h>
174cd4b1	29	#include <linux/sched/signal.h>
06021292 ET	30	#include <net/ip.h>
06021292 ET	31
545cd5e5 AD	32	/* 0 - Reserved to indicate value not set
	33	* 1..NR_CPUS - Reserved for sender_cpu
	34	* NR_CPUS+1..~0 - Region available for NAPI IDs
	35	*/
	36	#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
	37
e4dde412 DB	38	#ifdef CONFIG_NET_RX_BUSY_POLL
	39
	40	struct napi_struct;
	41	extern unsigned int sysctl_net_busy_read __read_mostly;
	42	extern unsigned int sysctl_net_busy_poll __read_mostly;
	43
cbf55001	44	static inline bool net_busy_loop_on(void)
91e2fd33	45	{
64b0dc51	46	return sysctl_net_busy_poll;
91e2fd33 ET	47	}
91e2fd33 ET	48
37056719	49	static inline bool sk_can_busy_loop(const struct sock *sk)
ad6276e0	50	{
37056719	51	return sk->sk_ll_usec && !signal_pending(current);
ad6276e0	52	}
ad6276e0	53
7db6b048 SS	54	bool sk_busy_loop_end(void *p, unsigned long start_time);
	55
	56	void napi_busy_loop(unsigned int napi_id,
	57	bool (loop_end)(void , unsigned long),
	58	void *loop_end_arg);
9a3c71aa	59
37056719 AD	60	#else /* CONFIG_NET_RX_BUSY_POLL */
37056719 AD	61	static inline unsigned long net_busy_loop_on(void)
1bc2774d	62	{
37056719	63	return 0;
06021292 ET	64	}
06021292 ET	65
37056719	66	static inline bool sk_can_busy_loop(struct sock *sk)
06021292	67	{
37056719	68	return false;
06021292 ET	69	}
06021292 ET	70
37056719	71	#endif /* CONFIG_NET_RX_BUSY_POLL */
06021292	72
37056719	73	static inline unsigned long busy_loop_current_time(void)
91e2fd33	74	{
37056719 AD	75	#ifdef CONFIG_NET_RX_BUSY_POLL
	76	return (unsigned long)(local_clock() >> 10);
	77	#else
91e2fd33	78	return 0;
37056719	79	#endif
91e2fd33	80	}
06021292	81
37056719 AD	82	/* in poll/select we use the global sysctl_net_ll_poll value */
37056719 AD	83	static inline bool busy_loop_timeout(unsigned long start_time)
06021292	84	{
37056719 AD	85	#ifdef CONFIG_NET_RX_BUSY_POLL
37056719 AD	86	unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll);
06021292	87
37056719 AD	88	if (bp_usec) {
	89	unsigned long end_time = start_time + bp_usec;
	90	unsigned long now = busy_loop_current_time();
06021292	91
37056719 AD	92	return time_after(now, end_time);
	93	}
	94	#endif
76b1e9b9	95	return true;
06021292 ET	96	}
06021292 ET	97
37056719 AD	98	static inline bool sk_busy_loop_timeout(struct sock *sk,
37056719 AD	99	unsigned long start_time)
dfcefb0b	100	{
37056719 AD	101	#ifdef CONFIG_NET_RX_BUSY_POLL
37056719 AD	102	unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec);
dfcefb0b	103
37056719 AD	104	if (bp_usec) {
	105	unsigned long end_time = start_time + bp_usec;
	106	unsigned long now = busy_loop_current_time();
	107
	108	return time_after(now, end_time);
	109	}
	110	#endif
	111	return true;
	112	}
e68b6e50	113
7db6b048 SS	114	static inline void sk_busy_loop(struct sock *sk, int nonblock)
	115	{
	116	#ifdef CONFIG_NET_RX_BUSY_POLL
	117	unsigned int napi_id = READ_ONCE(sk->sk_napi_id);
	118
	119	if (napi_id >= MIN_NAPI_ID)
	120	napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk);
	121	#endif
	122	}
	123
d2e64dbb AD	124	/* used in the NIC receive handler to mark the skb */
	125	static inline void skb_mark_napi_id(struct sk_buff *skb,
	126	struct napi_struct *napi)
	127	{
	128	#ifdef CONFIG_NET_RX_BUSY_POLL
	129	skb->napi_id = napi->napi_id;
	130	#endif
	131	}
	132
e68b6e50 ED	133	/* used in the protocol hanlder to propagate the napi_id to the socket */
	134	static inline void sk_mark_napi_id(struct sock sk, const struct sk_buff skb)
	135	{
	136	#ifdef CONFIG_NET_RX_BUSY_POLL
4e6660f3	137	WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
e68b6e50 ED	138	#endif
	139	}
	140
	141	/* variant used for unconnected sockets */
	142	static inline void sk_mark_napi_id_once(struct sock *sk,
	143	const struct sk_buff *skb)
	144	{
	145	#ifdef CONFIG_NET_RX_BUSY_POLL
4e6660f3 ED	146	if (!READ_ONCE(sk->sk_napi_id))
4e6660f3 ED	147	WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
e68b6e50 ED	148	#endif
	149	}
	150
8b80cda5	151	#endif /* _LINUX_NET_BUSY_POLL_H */