/*
 * net/core/dst_cache.c - dst entry cache
 *
 * Copyright (c) 2016 Paolo Abeni <pabeni@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/percpu.h>
#include <net/dst_cache.h>
#include <net/route.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ip6_fib.h>
#endif
#include <uapi/linux/in.h>

struct dst_cache_pcpu {
	unsigned long refresh_ts;
	struct dst_entry *dst;
	u32 cookie;
	union {
		struct in_addr in_saddr;
		struct in6_addr in6_saddr;
	};
};

static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache,
				      struct dst_entry *dst, u32 cookie)
{
	dst_release(dst_cache->dst);
	if (dst)
		dst_hold(dst);

	dst_cache->cookie = cookie;
	dst_cache->dst = dst;
}

static struct dst_entry *dst_cache_per_cpu_get(struct dst_cache *dst_cache,
					       struct dst_cache_pcpu *idst)
{
	struct dst_entry *dst;

	dst = idst->dst;
	if (!dst)
		goto fail;

	/* the cache already hold a dst reference; it can't go away */
	dst_hold(dst);

	if (unlikely(!time_after(idst->refresh_ts, dst_cache->reset_ts) ||
		     (dst->obsolete && !dst->ops->check(dst, idst->cookie)))) {
		dst_cache_per_cpu_dst_set(idst, NULL, 0);
		dst_release(dst);
		goto fail;
	}
	return dst;

fail:
	idst->refresh_ts = jiffies;
	return NULL;
}

struct dst_entry *dst_cache_get(struct dst_cache *dst_cache)
{
	if (!dst_cache->cache)
		return NULL;

	return dst_cache_per_cpu_get(dst_cache, this_cpu_ptr(dst_cache->cache));
}
EXPORT_SYMBOL_GPL(dst_cache_get);

struct rtable *dst_cache_get_ip4(struct dst_cache *dst_cache, __be32 *saddr)
{
	struct dst_cache_pcpu *idst;
	struct dst_entry *dst;

	if (!dst_cache->cache)
		return NULL;

	idst = this_cpu_ptr(dst_cache->cache);
	dst = dst_cache_per_cpu_get(dst_cache, idst);
	if (!dst)
		return NULL;

	*saddr = idst->in_saddr.s_addr;
	return container_of(dst, struct rtable, dst);
}
EXPORT_SYMBOL_GPL(dst_cache_get_ip4);

void dst_cache_set_ip4(struct dst_cache *dst_cache, struct dst_entry *dst,
		       __be32 saddr)
{
	struct dst_cache_pcpu *idst;

	if (!dst_cache->cache)
		return;

	idst = this_cpu_ptr(dst_cache->cache);
	dst_cache_per_cpu_dst_set(idst, dst, 0);
	idst->in_saddr.s_addr = saddr;
}
EXPORT_SYMBOL_GPL(dst_cache_set_ip4);

#if IS_ENABLED(CONFIG_IPV6)
void dst_cache_set_ip6(struct dst_cache *dst_cache, struct dst_entry *dst,
		       const struct in6_addr *addr)
{
	struct dst_cache_pcpu *idst;

	if (!dst_cache->cache)
		return;

	idst = this_cpu_ptr(dst_cache->cache);
	dst_cache_per_cpu_dst_set(this_cpu_ptr(dst_cache->cache), dst,
				  rt6_get_cookie((struct rt6_info *)dst));
	idst->in6_saddr = *addr;
}
EXPORT_SYMBOL_GPL(dst_cache_set_ip6);

struct dst_entry *dst_cache_get_ip6(struct dst_cache *dst_cache,
				    struct in6_addr *saddr)
{
	struct dst_cache_pcpu *idst;
	struct dst_entry *dst;

	if (!dst_cache->cache)
		return NULL;

	idst = this_cpu_ptr(dst_cache->cache);
	dst = dst_cache_per_cpu_get(dst_cache, idst);
	if (!dst)
		return NULL;

	*saddr = idst->in6_saddr;
	return dst;
}
EXPORT_SYMBOL_GPL(dst_cache_get_ip6);
#endif

int dst_cache_init(struct dst_cache *dst_cache, gfp_t gfp)
{
	dst_cache->cache = alloc_percpu_gfp(struct dst_cache_pcpu,
					    gfp | __GFP_ZERO);
	if (!dst_cache->cache)
		return -ENOMEM;

	dst_cache_reset(dst_cache);
	return 0;
}
EXPORT_SYMBOL_GPL(dst_cache_init);

void dst_cache_destroy(struct dst_cache *dst_cache)
{
	int i;

	if (!dst_cache->cache)
		return;

	for_each_possible_cpu(i)
		dst_release(per_cpu_ptr(dst_cache->cache, i)->dst);

	free_percpu(dst_cache->cache);
}
EXPORT_SYMBOL_GPL(dst_cache_destroy);
</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Aleksander Morgado &lt;aleksander@aleksander.es&gt;</td><td class='right'>2017-01-18 21:31:31 +0100</td></tr>
<tr><th>committer</th><td>Johan Hovold &lt;johan@kernel.org&gt;</td><td class='right'>2017-01-19 09:08:37 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ipx/ipx_route.c?id=24d615a694d649aa2e167c3f97f62bdad07e3f84'>24d615a694d649aa2e167c3f97f62bdad07e3f84</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/ipx/ipx_route.c?id=24d615a694d649aa2e167c3f97f62bdad07e3f84'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=24d615a694d649aa2e167c3f97f62bdad07e3f84'>2fe33c115bdec6bf4b01e27afd90bb16fa668e22</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/ipx/ipx_route.c?id=24d615a694d649aa2e167c3f97f62bdad07e3f84'>net/ipx/ipx_route.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ipx/ipx_route.c?id=49def1853334396f948dcb4cedb9347abb318df5'>49def1853334396f948dcb4cedb9347abb318df5</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/ipx/ipx_route.c?id=24d615a694d649aa2e167c3f97f62bdad07e3f84&amp;id2=49def1853334396f948dcb4cedb9347abb318df5'>diff</a>)</td></tr></table>
<div class='commit-subject'>USB: serial: qcserial: add Dell DW5570 QDL</div><div class='commit-msg'>The Dell DW5570 is a re-branded Sierra Wireless MC8805 which will by
default boot with vid 0x413c and pid 0x81a3. When triggered QDL download
mode, the device switches to pid 0x81a6 and provides the standard TTY
used for firmware upgrade.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Aleksander Morgado &lt;aleksander@aleksander.es&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=24d615a694d649aa2e167c3f97f62bdad07e3f84'>Diffstat</a> (limited to 'net/ipx/ipx_route.c')</div><table summary='diffstat' class='diffstat'>