linux-stable/include/net/busy_poll.h
Thomas Gleixner a61127c213 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 111 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:06 +02:00

140 lines
3.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* net busy poll support
* Copyright(c) 2013 Intel Corporation.
*
* 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
sk->sk_napi_id = skb->napi_id;
#endif
sk_rx_queue_set(sk, skb);
}
/* 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 */