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 <linux/sched/clock.h> 29 #include <linux/sched/signal.h> 30 #include <net/ip.h> 31 32 #ifdef CONFIG_NET_RX_BUSY_POLL 33 34 struct napi_struct; 35 extern unsigned int sysctl_net_busy_read __read_mostly; 36 extern unsigned int sysctl_net_busy_poll __read_mostly; 37 38 static inline bool net_busy_loop_on(void) 39 { 40 return sysctl_net_busy_poll; 41 } 42 43 static inline u64 busy_loop_us_clock(void) 44 { 45 return local_clock() >> 10; 46 } 47 48 static inline unsigned long sk_busy_loop_end_time(struct sock *sk) 49 { 50 return busy_loop_us_clock() + ACCESS_ONCE(sk->sk_ll_usec); 51 } 52 53 /* in poll/select we use the global sysctl_net_ll_poll value */ 54 static inline unsigned long busy_loop_end_time(void) 55 { 56 return busy_loop_us_clock() + ACCESS_ONCE(sysctl_net_busy_poll); 57 } 58 59 static inline bool sk_can_busy_loop(const struct sock *sk) 60 { 61 return sk->sk_ll_usec && sk->sk_napi_id && !signal_pending(current); 62 } 63 64 65 static inline bool busy_loop_timeout(unsigned long end_time) 66 { 67 unsigned long now = busy_loop_us_clock(); 68 69 return time_after(now, end_time); 70 } 71 72 bool sk_busy_loop(struct sock *sk, int nonblock); 73 74 /* used in the NIC receive handler to mark the skb */ 75 static inline void skb_mark_napi_id(struct sk_buff *skb, 76 struct napi_struct *napi) 77 { 78 skb->napi_id = napi->napi_id; 79 } 80 81 82 #else /* CONFIG_NET_RX_BUSY_POLL */ 83 static inline unsigned long net_busy_loop_on(void) 84 { 85 return 0; 86 } 87 88 static inline unsigned long busy_loop_end_time(void) 89 { 90 return 0; 91 } 92 93 static inline bool sk_can_busy_loop(struct sock *sk) 94 { 95 return false; 96 } 97 98 static inline void skb_mark_napi_id(struct sk_buff *skb, 99 struct napi_struct *napi) 100 { 101 } 102 103 static inline bool busy_loop_timeout(unsigned long end_time) 104 { 105 return true; 106 } 107 108 static inline bool sk_busy_loop(struct sock *sk, int nonblock) 109 { 110 return false; 111 } 112 113 #endif /* CONFIG_NET_RX_BUSY_POLL */ 114 115 /* used in the protocol hanlder to propagate the napi_id to the socket */ 116 static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb) 117 { 118 #ifdef CONFIG_NET_RX_BUSY_POLL 119 sk->sk_napi_id = skb->napi_id; 120 #endif 121 } 122 123 /* variant used for unconnected sockets */ 124 static inline void sk_mark_napi_id_once(struct sock *sk, 125 const struct sk_buff *skb) 126 { 127 #ifdef CONFIG_NET_RX_BUSY_POLL 128 if (!sk->sk_napi_id) 129 sk->sk_napi_id = skb->napi_id; 130 #endif 131 } 132 133 #endif /* _LINUX_NET_BUSY_POLL_H */ 134