Current File : //usr/src/kernels/3.10.0-1160.81.1.el7.centos.plus.x86_64/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
/* 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))
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(const struct sock *sk)
{
return sk->sk_ll_usec && !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 bool sk_busy_poll(struct sock *sk, int nonblock)
{
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 */
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