#ifndef __TRIGGER_H_
#define __TRIGGER_H_ 1

#include "util/debug.h"
#include "asm/bug.h"

/*
 * Use trigger to model operations which need to be executed when
 * an event (a signal, for example) is observed.
 *
 * States and transits:
 *
 *
 *  OFF--(on)--> READY --(hit)--> HIT
 *                 ^               |
 *                 |            (ready)
 *                 |               |
 *                  \_____________/
 *
 * is_hit and is_ready are two key functions to query the state of
 * a trigger. is_hit means the event already happen; is_ready means the
 * trigger is waiting for the event.
 */

struct trigger {
	volatile enum {
		TRIGGER_ERROR		= -2,
		TRIGGER_OFF		= -1,
		TRIGGER_READY		= 0,
		TRIGGER_HIT		= 1,
	} state;
	const char *name;
};

#define TRIGGER_WARN_ONCE(t, exp) \
	WARN_ONCE(t->state != exp, "trigger '%s' state transist error: %d in %s()\n", \
		  t->name, t->state, __func__)

static inline bool trigger_is_available(struct trigger *t)
{
	return t->state >= 0;
}

static inline bool trigger_is_error(struct trigger *t)
{
	return t->state <= TRIGGER_ERROR;
}

static inline void trigger_on(struct trigger *t)
{
	TRIGGER_WARN_ONCE(t, TRIGGER_OFF);
	t->state = TRIGGER_READY;
}

static inline void trigger_ready(struct trigger *t)
{
	if (!trigger_is_available(t))
		return;
	t->state = TRIGGER_READY;
}

static inline void trigger_hit(struct trigger *t)
{
	if (!trigger_is_available(t))
		return;
	TRIGGER_WARN_ONCE(t, TRIGGER_READY);
	t->state = TRIGGER_HIT;
}

static inline void trigger_off(struct trigger *t)
{
	if (!trigger_is_available(t))
		return;
	t->state = TRIGGER_OFF;
}

static inline void trigger_error(struct trigger *t)
{
	t->state = TRIGGER_ERROR;
}

static inline bool trigger_is_ready(struct trigger *t)
{
	return t->state == TRIGGER_READY;
}

static inline bool trigger_is_hit(struct trigger *t)
{
	return t->state == TRIGGER_HIT;
}

#define DEFINE_TRIGGER(n) \
struct trigger n = {.state = TRIGGER_OFF, .name = #n}
#endif
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/fs?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>fs</a>/<a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>xfs</a>/<a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs/xfs_stats.c?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>xfs_stats.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='2e4333c14de06a333783d6812cf3c4998f78b0c8'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</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>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-11 10:17:39 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-11 10:17:39 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs/xfs_stats.c?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>2e4333c14de06a333783d6812cf3c4998f78b0c8</a> (<a href='/cgit.cgi/linux/net-next.git/patch/fs/xfs/xfs_stats.c?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>368428514d70f34f2261c7f954f241f886d6bb51</a> /<a href='/cgit.cgi/linux/net-next.git/tree/fs/xfs/xfs_stats.c?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>fs/xfs/xfs_stats.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs/xfs_stats.c?id=045169816b31b10faed984b01c390db1b32ee4c1'>045169816b31b10faed984b01c390db1b32ee4c1</a> (<a href='/cgit.cgi/linux/net-next.git/diff/fs/xfs/xfs_stats.c?id=2e4333c14de06a333783d6812cf3c4998f78b0c8&amp;id2=045169816b31b10faed984b01c390db1b32ee4c1'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs/xfs_stats.c?id=ba735155b9647b6167fd50276ca0fbfbce4e836c'>ba735155b9647b6167fd50276ca0fbfbce4e836c</a> (<a href='/cgit.cgi/linux/net-next.git/diff/fs/xfs/xfs_stats.c?id=2e4333c14de06a333783d6812cf3c4998f78b0c8&amp;id2=ba735155b9647b6167fd50276ca0fbfbce4e836c'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus</div><div class='commit-msg'>Pull MIPS fixes from Ralf Baechle:
 "Two more MIPS fixes for 4.9:

   - RTC: Return -ENODEV so an external RTC will be tried

   - Fix mask of GPE frequency

  These two have been tested on Imagination's automated test system and
  also both received positive reviews on the linux-mips mailing list"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: Lantiq: Fix mask of GPE frequency
  MIPS: Return -ENODEV from weak implementation of rtc_mips_set_time
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=2e4333c14de06a333783d6812cf3c4998f78b0c8'>Diffstat</a> (limited to 'fs/xfs/xfs_stats.c')</div><table summary='diffstat' class='diffstat'>