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Diffstat (limited to '')
| -rw-r--r-- | include/net/busy_poll.h | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h new file mode 100644 index 000000000..f90f0021f --- /dev/null +++ b/include/net/busy_poll.h @@ -0,0 +1,177 @@ +/* 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)) + +#define BUSY_POLL_BUDGET 8 + +#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 READ_ONCE(sysctl_net_busy_poll); +} + +static inline bool sk_can_busy_loop(const struct sock *sk) +{ + return READ_ONCE(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, bool prefer_busy_poll, u16 budget); + +#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, + READ_ONCE(sk->sk_prefer_busy_poll), + READ_ONCE(sk->sk_busy_poll_budget) ?: BUSY_POLL_BUDGET); +#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 + /* If the skb was already marked with a valid NAPI ID, avoid overwriting + * it. + */ + if (skb->napi_id < MIN_NAPI_ID) + 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 + if (unlikely(READ_ONCE(sk->sk_napi_id) != skb->napi_id)) + WRITE_ONCE(sk->sk_napi_id, skb->napi_id); +#endif + sk_rx_queue_update(sk, skb); +} + +/* Variant of sk_mark_napi_id() for passive flow setup, + * as sk->sk_napi_id and sk->sk_rx_queue_mapping content + * needs to be set. + */ +static inline void sk_mark_napi_id_set(struct sock *sk, + const struct sk_buff *skb) +{ +#ifdef CONFIG_NET_RX_BUSY_POLL + WRITE_ONCE(sk->sk_napi_id, skb->napi_id); +#endif + sk_rx_queue_set(sk, skb); +} + +static inline void __sk_mark_napi_id_once(struct sock *sk, unsigned int napi_id) +{ +#ifdef CONFIG_NET_RX_BUSY_POLL + if (!READ_ONCE(sk->sk_napi_id)) + WRITE_ONCE(sk->sk_napi_id, 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 + __sk_mark_napi_id_once(sk, skb->napi_id); +#endif +} + +static inline void sk_mark_napi_id_once_xdp(struct sock *sk, + const struct xdp_buff *xdp) +{ +#ifdef CONFIG_NET_RX_BUSY_POLL + __sk_mark_napi_id_once(sk, xdp->rxq->napi_id); +#endif +} + +#endif /* _LINUX_NET_BUSY_POLL_H */ |