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