#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt

#include <linux/notifier.h>

#include <xen/xen.h>
#include <xen/xenbus.h>

#include <asm/xen/hypervisor.h>
#include <asm/cpu.h>

static void enable_hotplug_cpu(int cpu)
{
	if (!cpu_present(cpu))
		xen_arch_register_cpu(cpu);

	set_cpu_present(cpu, true);
}

static void disable_hotplug_cpu(int cpu)
{
	if (cpu_online(cpu)) {
		lock_device_hotplug();
		device_offline(get_cpu_device(cpu));
		unlock_device_hotplug();
	}
	if (cpu_present(cpu))
		xen_arch_unregister_cpu(cpu);

	set_cpu_present(cpu, false);
}

static int vcpu_online(unsigned int cpu)
{
	int err;
	char dir[16], state[16];

	sprintf(dir, "cpu/%u", cpu);
	err = xenbus_scanf(XBT_NIL, dir, "availability", "%15s", state);
	if (err != 1) {
		if (!xen_initial_domain())
			pr_err("Unable to read cpu state\n");
		return err;
	}

	if (strcmp(state, "online") == 0)
		return 1;
	else if (strcmp(state, "offline") == 0)
		return 0;

	pr_err("unknown state(%s) on CPU%d\n", state, cpu);
	return -EINVAL;
}
static void vcpu_hotplug(unsigned int cpu)
{
	if (!cpu_possible(cpu))
		return;

	switch (vcpu_online(cpu)) {
	case 1:
		enable_hotplug_cpu(cpu);
		break;
	case 0:
		disable_hotplug_cpu(cpu);
		break;
	default:
		break;
	}
}

static void handle_vcpu_hotplug_event(struct xenbus_watch *watch,
					const char **vec, unsigned int len)
{
	unsigned int cpu;
	char *cpustr;
	const char *node = vec[XS_WATCH_PATH];

	cpustr = strstr(node, "cpu/");
	if (cpustr != NULL) {
		sscanf(cpustr, "cpu/%u", &cpu);
		vcpu_hotplug(cpu);
	}
}

static int setup_cpu_watcher(struct notifier_block *notifier,
			      unsigned long event, void *data)
{
	int cpu;
	static struct xenbus_watch cpu_watch = {
		.node = "cpu",
		.callback = handle_vcpu_hotplug_event};

	(void)register_xenbus_watch(&cpu_watch);

	for_each_possible_cpu(cpu) {
		if (vcpu_online(cpu) == 0) {
			(void)cpu_down(cpu);
			set_cpu_present(cpu, false);
		}
	}

	return NOTIFY_DONE;
}

static int __init setup_vcpu_hotplug_event(void)
{
	static struct notifier_block xsn_cpu = {
		.notifier_call = setup_cpu_watcher };

#ifdef CONFIG_X86
	if (!xen_pv_domain())
#else
	if (!xen_domain())
#endif
		return -ENODEV;

	register_xenstore_notifier(&xsn_cpu);

	return 0;
}

arch_initcall(setup_vcpu_hotplug_event);

.c?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/tools/gpio/gpio-event-mon.c'>
<input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/tools?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>tools</a>/<a href='/cgit.cgi/linux/net-next.git/commit/tools/gpio?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>gpio</a>/<a href='/cgit.cgi/linux/net-next.git/commit/tools/gpio/gpio-event-mon.c?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>gpio-event-mon.c</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='f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'/><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'>2017-01-30 15:47:19 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-30 15:47:19 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/gpio/gpio-event-mon.c?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/gpio/gpio-event-mon.c?id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>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=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>4078d3ae27d4ebb85bdcd4d84e9b9a4d059f22bb</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/gpio/gpio-event-mon.c?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>tools/gpio/gpio-event-mon.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/gpio/gpio-event-mon.c?h=nds-private-remove&amp;id=751321b3dd5040dc5be19bd23f985e80c914621a'>751321b3dd5040dc5be19bd23f985e80c914621a</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/gpio/gpio-event-mon.c?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b&amp;id2=751321b3dd5040dc5be19bd23f985e80c914621a'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/gpio/gpio-event-mon.c?h=nds-private-remove&amp;id=54791b276b4000b307339f269d3bf7db877d536f'>54791b276b4000b307339f269d3bf7db877d536f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/gpio/gpio-event-mon.c?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b&amp;id2=54791b276b4000b307339f269d3bf7db877d536f'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc</div><div class='commit-msg'>Pull sparc fixes from David Miller:
 "Several small bug fixes and tidies, along with a fix for non-resumable
  memory errors triggered by userspace"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Handle PIO &amp; MEM non-resumable errors.
  sparc64: Zero pages on allocation for mondo and error queues.
  sparc: Fixed typo in sstate.c. Replaced panicing with panicking
  sparc: use symbolic names for tsb indexing
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=f9a42e0d58cf0fe3d902e63d4582f2ea4cd2bb8b'>Diffstat</a> (limited to 'tools/gpio/gpio-event-mon.c')</div><table summary='diffstat' class='diffstat'>