1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _NET_DST_CACHE_H
  3#define _NET_DST_CACHE_H
  4
  5#include <linux/jiffies.h>
  6#include <net/dst.h>
  7#if IS_ENABLED(CONFIG_IPV6)
  8#include <net/ip6_fib.h>
  9#endif
 10
 11struct dst_cache {
 12	struct dst_cache_pcpu __percpu *cache;
 13	unsigned long reset_ts;
 14};
 15
 16/**
 17 *	dst_cache_get - perform cache lookup
 18 *	@dst_cache: the cache
 19 *
 20 *	The caller should use dst_cache_get_ip4() if it need to retrieve the
 21 *	source address to be used when xmitting to the cached dst.
 22 *	local BH must be disabled.
 23 */
 24struct dst_entry *dst_cache_get(struct dst_cache *dst_cache);
 25
 26/**
 27 *	dst_cache_get_ip4 - perform cache lookup and fetch ipv4 source address
 28 *	@dst_cache: the cache
 29 *	@saddr: return value for the retrieved source address
 30 *
 31 *	local BH must be disabled.
 32 */
 33struct rtable *dst_cache_get_ip4(struct dst_cache *dst_cache, __be32 *saddr);
 34
 35/**
 36 *	dst_cache_set_ip4 - store the ipv4 dst into the cache
 37 *	@dst_cache: the cache
 38 *	@dst: the entry to be cached
 39 *	@saddr: the source address to be stored inside the cache
 40 *
 41 *	local BH must be disabled.
 42 */
 43void dst_cache_set_ip4(struct dst_cache *dst_cache, struct dst_entry *dst,
 44		       __be32 saddr);
 45
 46#if IS_ENABLED(CONFIG_IPV6)
 47
 48/**
 49 *	dst_cache_set_ip6 - store the ipv6 dst into the cache
 50 *	@dst_cache: the cache
 51 *	@dst: the entry to be cached
 52 *	@saddr: the source address to be stored inside the cache
 53 *
 54 *	local BH must be disabled.
 55 */
 56void dst_cache_set_ip6(struct dst_cache *dst_cache, struct dst_entry *dst,
 57		       const struct in6_addr *saddr);
 58
 59/**
 60 *	dst_cache_get_ip6 - perform cache lookup and fetch ipv6 source address
 61 *	@dst_cache: the cache
 62 *	@saddr: return value for the retrieved source address
 63 *
 64 *	local BH must be disabled.
 65 */
 66struct dst_entry *dst_cache_get_ip6(struct dst_cache *dst_cache,
 67				    struct in6_addr *saddr);
 68#endif
 69
 70/**
 71 *	dst_cache_reset - invalidate the cache contents
 72 *	@dst_cache: the cache
 73 *
 74 *	This does not free the cached dst to avoid races and contentions.
 75 *	the dst will be freed on later cache lookup.
 76 */
 77static inline void dst_cache_reset(struct dst_cache *dst_cache)
 78{
 79	dst_cache->reset_ts = jiffies;
 80}
 81
 82/**
 83 *	dst_cache_reset_now - invalidate the cache contents immediately
 84 *	@dst_cache: the cache
 85 *
 86 *	The caller must be sure there are no concurrent users, as this frees
 87 *	all dst_cache users immediately, rather than waiting for the next
 88 *	per-cpu usage like dst_cache_reset does. Most callers should use the
 89 *	higher speed lazily-freed dst_cache_reset function instead.
 90 */
 91void dst_cache_reset_now(struct dst_cache *dst_cache);
 92
 93/**
 94 *	dst_cache_init - initialize the cache, allocating the required storage
 95 *	@dst_cache: the cache
 96 *	@gfp: allocation flags
 97 */
 98int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp);
 99
100/**
101 *	dst_cache_destroy - empty the cache and free the allocated storage
102 *	@dst_cache: the cache
103 *
104 *	No synchronization is enforced: it must be called only when the cache
105 *	is unsed.
106 */
107void dst_cache_destroy(struct dst_cache *dst_cache);
108
109#endif