/*
 * linux/kernel/time/tick-broadcast-hrtimer.c
 * This file emulates a local clock event device
 * via a pseudo clock device.
 */
#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/hrtimer.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/profile.h>
#include <linux/clockchips.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/module.h>

#include "tick-internal.h"

static struct hrtimer bctimer;

static int bc_shutdown(struct clock_event_device *evt)
{
	/*
	 * Note, we cannot cancel the timer here as we might
	 * run into the following live lock scenario:
	 *
	 * cpu 0		cpu1
	 * lock(broadcast_lock);
	 *			hrtimer_interrupt()
	 *			bc_handler()
	 *			   tick_handle_oneshot_broadcast();
	 *			    lock(broadcast_lock);
	 * hrtimer_cancel()
	 *  wait_for_callback()
	 */
	hrtimer_try_to_cancel(&bctimer);
	return 0;
}

/*
 * This is called from the guts of the broadcast code when the cpu
 * which is about to enter idle has the earliest broadcast timer event.
 */
static int bc_set_next(ktime_t expires, struct clock_event_device *bc)
{
	int bc_moved;
	/*
	 * We try to cancel the timer first. If the callback is on
	 * flight on some other cpu then we let it handle it. If we
	 * were able to cancel the timer nothing can rearm it as we
	 * own broadcast_lock.
	 *
	 * However we can also be called from the event handler of
	 * ce_broadcast_hrtimer itself when it expires. We cannot
	 * restart the timer because we are in the callback, but we
	 * can set the expiry time and let the callback return
	 * HRTIMER_RESTART.
	 *
	 * Since we are in the idle loop at this point and because
	 * hrtimer_{start/cancel} functions call into tracing,
	 * calls to these functions must be bound within RCU_NONIDLE.
	 */
	RCU_NONIDLE({
			bc_moved = hrtimer_try_to_cancel(&bctimer) >= 0;
			if (bc_moved)
				hrtimer_start(&bctimer, expires,
					      HRTIMER_MODE_ABS_PINNED);});
	if (bc_moved) {
		/* Bind the "device" to the cpu */
		bc->bound_on = smp_processor_id();
	} else if (bc->bound_on == smp_processor_id()) {
		hrtimer_set_expires(&bctimer, expires);
	}
	return 0;
}

static struct clock_event_device ce_broadcast_hrtimer = {
	.name			= "bc_hrtimer",
	.set_state_shutdown	= bc_shutdown,
	.set_next_ktime		= bc_set_next,
	.features		= CLOCK_EVT_FEAT_ONESHOT |
				  CLOCK_EVT_FEAT_KTIME |
				  CLOCK_EVT_FEAT_HRTIMER,
	.rating			= 0,
	.bound_on		= -1,
	.min_delta_ns		= 1,
	.max_delta_ns		= KTIME_MAX,
	.min_delta_ticks	= 1,
	.max_delta_ticks	= ULONG_MAX,
	.mult			= 1,
	.shift			= 0,
	.cpumask		= cpu_all_mask,
};

static enum hrtimer_restart bc_handler(struct hrtimer *t)
{
	ce_broadcast_hrtimer.event_handler(&ce_broadcast_hrtimer);

	if (clockevent_state_oneshot(&ce_broadcast_hrtimer))
		if (ce_broadcast_hrtimer.next_event != KTIME_MAX)
			return HRTIMER_RESTART;

	return HRTIMER_NORESTART;
}

void tick_setup_hrtimer_broadcast(void)
{
	hrtimer_init(&bctimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
	bctimer.function = bc_handler;
	clockevents_register_device(&ce_broadcast_hrtimer);
}
cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>include</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>dt-bindings</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/clock?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>clock</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/clock/imx6sl-clock.h?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>imx6sl-clock.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='3ddc76dfc786cc6f87852693227fb0b1f124f807'/><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'>2016-12-25 14:30:04 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-25 14:30:04 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/clock/imx6sl-clock.h?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>3ddc76dfc786cc6f87852693227fb0b1f124f807</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/dt-bindings/clock/imx6sl-clock.h?id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>8192b4721e05cf6823087f9696db8c0c8f144b02</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/dt-bindings/clock/imx6sl-clock.h?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>include/dt-bindings/clock/imx6sl-clock.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/clock/imx6sl-clock.h?h=nds-private-remove&amp;id=b272f732f888d4cf43c943a40c9aaa836f9b7431'>b272f732f888d4cf43c943a40c9aaa836f9b7431</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/dt-bindings/clock/imx6sl-clock.h?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807&amp;id2=b272f732f888d4cf43c943a40c9aaa836f9b7431'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/dt-bindings/clock/imx6sl-clock.h?h=nds-private-remove&amp;id=1f3a8e49d8f28f498b8694464623ac20aebfe62a'>1f3a8e49d8f28f498b8694464623ac20aebfe62a</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/dt-bindings/clock/imx6sl-clock.h?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807&amp;id2=1f3a8e49d8f28f498b8694464623ac20aebfe62a'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</div><div class='commit-msg'>Pull timer type cleanups from Thomas Gleixner:
 "This series does a tree wide cleanup of types related to
  timers/timekeeping.

   - Get rid of cycles_t and use a plain u64. The type is not really
     helpful and caused more confusion than clarity

   - Get rid of the ktime union. The union has become useless as we use
     the scalar nanoseconds storage unconditionally now. The 32bit
     timespec alike storage got removed due to the Y2038 limitations
     some time ago.

     That leaves the odd union access around for no reason. Clean it up.

  Both changes have been done with coccinelle and a small amount of
  manual mopping up"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ktime: Get rid of ktime_equal()
  ktime: Cleanup ktime_set() usage
  ktime: Get rid of the union
  clocksource: Use a plain u64 instead of cycle_t
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=3ddc76dfc786cc6f87852693227fb0b1f124f807'>Diffstat</a> (limited to 'include/dt-bindings/clock/imx6sl-clock.h')</div><table summary='diffstat' class='diffstat'>