/*
 * 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);
ass='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>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-08 11:42:04 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-08 11:42:04 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/drm?id=83280e90ef001f77a64e2ce59c25ab66e47ab1f0'>83280e90ef001f77a64e2ce59c25ab66e47ab1f0</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/drm?id=83280e90ef001f77a64e2ce59c25ab66e47ab1f0'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=83280e90ef001f77a64e2ce59c25ab66e47ab1f0'>ec0a5842e2fbc0f4abaff55299acac397b8da5c3</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/drm?id=83280e90ef001f77a64e2ce59c25ab66e47ab1f0'>include/drm</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/drm?id=cc250e267bd56c531b0bee455fc724d50af83fac'>cc250e267bd56c531b0bee455fc724d50af83fac</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/drm?id=83280e90ef001f77a64e2ce59c25ab66e47ab1f0&amp;id2=cc250e267bd56c531b0bee455fc724d50af83fac'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/drm?id=0a8fd1346254974c3a852338508e4a4cddbb35f1'>0a8fd1346254974c3a852338508e4a4cddbb35f1</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/drm?id=83280e90ef001f77a64e2ce59c25ab66e47ab1f0&amp;id2=0a8fd1346254974c3a852338508e4a4cddbb35f1'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge tag 'usb-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb</div><div class='commit-msg'>Pull USB fixes from Greg KH:
 "Here are a bunch of USB fixes for 4.10-rc3. Yeah, it's a lot, an
  artifact of the holiday break I think.

  Lots of gadget and the usual XHCI fixups for reported issues (one day
  that driver will calm down...) Also included are a bunch of usb-serial
  driver fixes, and for good measure, a number of much-reported MUSB
  driver issues have finally been resolved.

  All of these have been in linux-next with no reported issues"

* tag 'usb-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (72 commits)
  USB: fix problems with duplicate endpoint addresses
  usb: ohci-at91: use descriptor-based gpio APIs correctly
  usb: storage: unusual_uas: Add JMicron JMS56x to unusual device
  usb: hub: Move hub_port_disable() to fix warning if PM is disabled
  usb: musb: blackfin: add bfin_fifo_offset in bfin_ops
  usb: musb: fix compilation warning on unused function
  usb: musb: Fix trying to free already-free IRQ 4
  usb: musb: dsps: implement clear_ep_rxintr() callback
  usb: musb: core: add clear_ep_rxintr() to musb_platform_ops
  USB: serial: ti_usb_3410_5052: fix NULL-deref at open
  USB: serial: spcp8x5: fix NULL-deref at open
  USB: serial: quatech2: fix sleep-while-atomic in close
  USB: serial: pl2303: fix NULL-deref at open
  USB: serial: oti6858: fix NULL-deref at open
  USB: serial: omninet: fix NULL-derefs at open and disconnect
  USB: serial: mos7840: fix misleading interrupt-URB comment
  USB: serial: mos7840: remove unused write URB
  USB: serial: mos7840: fix NULL-deref at open
  USB: serial: mos7720: remove obsolete port initialisation
  USB: serial: mos7720: fix parallel probe
  ...
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=83280e90ef001f77a64e2ce59c25ab66e47ab1f0'>Diffstat</a> (limited to 'include/drm')</div><table summary='diffstat' class='diffstat'>