/*
 * linux/kernel/time/tick-oneshot.c
 *
 * This file contains functions which manage high resolution tick
 * related events.
 *
 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
 * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
 * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
 *
 * This code is licenced under the GPL version 2. For details see
 * kernel-base/COPYING.
 */
#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/sched.h>

#include "tick-internal.h"

/**
 * tick_program_event
 */
int tick_program_event(ktime_t expires, int force)
{
	struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);

	if (unlikely(expires == KTIME_MAX)) {
		/*
		 * We don't need the clock event device any more, stop it.
		 */
		clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT_STOPPED);
		return 0;
	}

	if (unlikely(clockevent_state_oneshot_stopped(dev))) {
		/*
		 * We need the clock event again, configure it in ONESHOT mode
		 * before using it.
		 */
		clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
	}

	return clockevents_program_event(dev, expires, force);
}

/**
 * tick_resume_onshot - resume oneshot mode
 */
void tick_resume_oneshot(void)
{
	struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);

	clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
	clockevents_program_event(dev, ktime_get(), true);
}

/**
 * tick_setup_oneshot - setup the event device for oneshot mode (hres or nohz)
 */
void tick_setup_oneshot(struct clock_event_device *newdev,
			void (*handler)(struct clock_event_device *),
			ktime_t next_event)
{
	newdev->event_handler = handler;
	clockevents_switch_state(newdev, CLOCK_EVT_STATE_ONESHOT);
	clockevents_program_event(newdev, next_event, true);
}

/**
 * tick_switch_to_oneshot - switch to oneshot mode
 */
int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
{
	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
	struct clock_event_device *dev = td->evtdev;

	if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
		    !tick_device_is_functional(dev)) {

		printk(KERN_INFO "Clockevents: "
		       "could not switch to one-shot mode:");
		if (!dev) {
			printk(" no tick device\n");
		} else {
			if (!tick_device_is_functional(dev))
				printk(" %s is not functional.\n", dev->name);
			else
				printk(" %s does not support one-shot mode.\n",
				       dev->name);
		}
		return -EINVAL;
	}

	td->mode = TICKDEV_MODE_ONESHOT;
	dev->event_handler = handler;
	clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
	tick_broadcast_switch_to_oneshot();
	return 0;
}

/**
 * tick_check_oneshot_mode - check whether the system is in oneshot mode
 *
 * returns 1 when either nohz or highres are enabled. otherwise 0.
 */
int tick_oneshot_mode_active(void)
{
	unsigned long flags;
	int ret;

	local_irq_save(flags);
	ret = __this_cpu_read(tick_cpu_device.mode) == TICKDEV_MODE_ONESHOT;
	local_irq_restore(flags);

	return ret;
}

#ifdef CONFIG_HIGH_RES_TIMERS
/**
 * tick_init_highres - switch to high resolution mode
 *
 * Called with interrupts disabled.
 */
int tick_init_highres(void)
{
	return tick_switch_to_oneshot(hrtimer_interrupt);
}
#endif
cgit.cgi/linux/net-next.git/commit/tools/objtool/.gitignore?h=nds-private-remove&amp;id=54791b276b4000b307339f269d3bf7db877d536f'>.gitignore</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='54791b276b4000b307339f269d3bf7db877d536f'/><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>David S. Miller &lt;davem@davemloft.net&gt;</td><td class='right'>2017-01-30 14:28:22 -0800</td></tr>
<tr><th>committer</th><td>David S. Miller &lt;davem@davemloft.net&gt;</td><td class='right'>2017-01-30 14:28:22 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/objtool/.gitignore?h=nds-private-remove&amp;id=54791b276b4000b307339f269d3bf7db877d536f'>54791b276b4000b307339f269d3bf7db877d536f</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/objtool/.gitignore?id=54791b276b4000b307339f269d3bf7db877d536f'>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=54791b276b4000b307339f269d3bf7db877d536f'>1c2616bd373ce5ea28aac2a53e32f5b5834901ce</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/objtool/.gitignore?h=nds-private-remove&amp;id=54791b276b4000b307339f269d3bf7db877d536f'>tools/objtool/.gitignore</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/objtool/.gitignore?h=nds-private-remove&amp;id=5d0e7705774dd412a465896d08d59a81a345c1e4'>5d0e7705774dd412a465896d08d59a81a345c1e4</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/objtool/.gitignore?h=nds-private-remove&amp;id=54791b276b4000b307339f269d3bf7db877d536f&amp;id2=5d0e7705774dd412a465896d08d59a81a345c1e4'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/objtool/.gitignore?h=nds-private-remove&amp;id=047487241ff59374fded8c477f21453681f5995c'>047487241ff59374fded8c477f21453681f5995c</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/objtool/.gitignore?h=nds-private-remove&amp;id=54791b276b4000b307339f269d3bf7db877d536f&amp;id2=047487241ff59374fded8c477f21453681f5995c'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'sparc64-non-resumable-user-error-recovery'</div><div class='commit-msg'>Liam R. Howlett says:

====================
sparc64: Recover from userspace non-resumable PIO &amp; MEM errors

A non-resumable error from userspace is able to cause a kernel panic or trap
loop due to the setup and handling of the queued traps once in the kernel.
This patch series addresses both of these issues.

The queues are fixed by simply zeroing the memory before use.

PIO errors from userspace will result in a SIGBUS being sent to the user
process.

The MEM errors form userspace will result in a SIGKILL and also cause the
offending pages to be claimed so they are no longer used in future tasks.
SIGKILL is used to ensure that the process does not try to coredump and result
in an attempt to read the memory again from within kernel space.  Although
there is a HV call to scrub the memory (mem_scrub), there is no easy way to
guarantee that the real memory address(es) are not used by other tasks.
Clearing the error with mem_scrub would zero the memory and cause the other
processes to proceed with bad data.

The handling of other non-resumable errors remain unchanged and will cause a
panic.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=54791b276b4000b307339f269d3bf7db877d536f'>Diffstat</a> (limited to 'tools/objtool/.gitignore')</div><table summary='diffstat' class='diffstat'>