167 lines
4.2 KiB
C
167 lines
4.2 KiB
C
/*
|
|
* 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
|
|
}
|
|
|
|
static inline void sock_poll_busy_loop(struct socket *sock, __poll_t events)
|
|
{
|
|
if (sk_can_busy_loop(sock->sk) &&
|
|
events && (events & POLL_BUSY_LOOP)) {
|
|
/* once, only if requested by syscall */
|
|
sk_busy_loop(sock->sk, 1);
|
|
}
|
|
}
|
|
|
|
/* if this socket can poll_ll, tell the system call */
|
|
static inline __poll_t sock_poll_busy_flag(struct socket *sock)
|
|
{
|
|
return sk_can_busy_loop(sock->sk) ? POLL_BUSY_LOOP : 0;
|
|
}
|
|
|
|
/* 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
|
|
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 (!sk->sk_napi_id)
|
|
sk->sk_napi_id = skb->napi_id;
|
|
#endif
|
|
}
|
|
|
|
#endif /* _LINUX_NET_BUSY_POLL_H */
|