[deliverable/linux.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 <net/ip.h>

#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;

/* return values from ndo_ll_poll */
#define LL_FLUSH_FAILED		-1
#define LL_FLUSH_BUSY		-2

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

static inline u64 busy_loop_us_clock(void)
{
	return local_clock() >> 10;
}

static inline unsigned long sk_busy_loop_end_time(struct sock *sk)
{
	return busy_loop_us_clock() + ACCESS_ONCE(sk->sk_ll_usec);
}

/* in poll/select we use the global sysctl_net_ll_poll value */
static inline unsigned long busy_loop_end_time(void)
{
	return busy_loop_us_clock() + ACCESS_ONCE(sysctl_net_busy_poll);
}

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


static inline bool busy_loop_timeout(unsigned long end_time)
{
	unsigned long now = busy_loop_us_clock();

	return time_after(now, end_time);
}

bool sk_busy_loop(struct sock *sk, int nonblock);

/* 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)
{
	skb->napi_id = napi->napi_id;
}

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

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

static inline unsigned long busy_loop_end_time(void)
{
	return 0;
}

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

static inline void skb_mark_napi_id(struct sk_buff *skb,
				    struct napi_struct *napi)
{
}

static inline void sk_mark_napi_id(struct sock *sk, struct sk_buff *skb)
{
}

static inline bool busy_loop_timeout(unsigned long end_time)
{
	return true;
}

static inline bool sk_busy_loop(struct sock *sk, int nonblock)
{
	return false;
}

#endif /* CONFIG_NET_RX_BUSY_POLL */
#endif /* _LINUX_NET_BUSY_POLL_H */
Commit	Line	Data
	1	/*
	2	* net busy poll support
	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
	24	#ifndef _LINUX_NET_BUSY_POLL_H
	25	#define _LINUX_NET_BUSY_POLL_H
	26
	27	#include <linux/netdevice.h>
	28	#include <net/ip.h>
	29
	30	#ifdef CONFIG_NET_RX_BUSY_POLL
	31
	32	struct napi_struct;
	33	extern unsigned int sysctl_net_busy_read __read_mostly;
	34	extern unsigned int sysctl_net_busy_poll __read_mostly;
	35
	36	/* return values from ndo_ll_poll */
	37	#define LL_FLUSH_FAILED -1
	38	#define LL_FLUSH_BUSY -2
	39
	40	static inline bool net_busy_loop_on(void)
	41	{
	42	return sysctl_net_busy_poll;
	43	}
	44
	45	static inline u64 busy_loop_us_clock(void)
	46	{
	47	return local_clock() >> 10;
	48	}
	49
	50	static inline unsigned long sk_busy_loop_end_time(struct sock *sk)
	51	{
	52	return busy_loop_us_clock() + ACCESS_ONCE(sk->sk_ll_usec);
	53	}
	54
	55	/* in poll/select we use the global sysctl_net_ll_poll value */
	56	static inline unsigned long busy_loop_end_time(void)
	57	{
	58	return busy_loop_us_clock() + ACCESS_ONCE(sysctl_net_busy_poll);
	59	}
	60
	61	static inline bool sk_can_busy_loop(struct sock *sk)
	62	{
	63	return sk->sk_ll_usec && sk->sk_napi_id &&
	64	!need_resched() && !signal_pending(current);
	65	}
	66
	67
	68	static inline bool busy_loop_timeout(unsigned long end_time)
	69	{
	70	unsigned long now = busy_loop_us_clock();
	71
	72	return time_after(now, end_time);
	73	}
	74
	75	bool sk_busy_loop(struct sock *sk, int nonblock);
	76
	77	/* used in the NIC receive handler to mark the skb */
	78	static inline void skb_mark_napi_id(struct sk_buff *skb,
	79	struct napi_struct *napi)
	80	{
	81	skb->napi_id = napi->napi_id;
	82	}
	83
	84	/* used in the protocol hanlder to propagate the napi_id to the socket */
	85	static inline void sk_mark_napi_id(struct sock sk, struct sk_buff skb)
	86	{
	87	sk->sk_napi_id = skb->napi_id;
	88	}
	89
	90	#else /* CONFIG_NET_RX_BUSY_POLL */
	91	static inline unsigned long net_busy_loop_on(void)
	92	{
	93	return 0;
	94	}
	95
	96	static inline unsigned long busy_loop_end_time(void)
	97	{
	98	return 0;
	99	}
	100
	101	static inline bool sk_can_busy_loop(struct sock *sk)
	102	{
	103	return false;
	104	}
	105
	106	static inline void skb_mark_napi_id(struct sk_buff *skb,
	107	struct napi_struct *napi)
	108	{
	109	}
	110
	111	static inline void sk_mark_napi_id(struct sock sk, struct sk_buff skb)
	112	{
	113	}
	114
	115	static inline bool busy_loop_timeout(unsigned long end_time)
	116	{
	117	return true;
	118	}
	119
	120	static inline bool sk_busy_loop(struct sock *sk, int nonblock)
	121	{
	122	return false;
	123	}
	124
	125	#endif /* CONFIG_NET_RX_BUSY_POLL */
	126	#endif /* _LINUX_NET_BUSY_POLL_H */