[linux.git] / kernel / reboot.c

/*
 *  linux/kernel/reboot.c
 *
 *  Copyright (C) 2013  Linus Torvalds
 */

#define pr_fmt(fmt)	"reboot: " fmt

#include <linux/ctype.h>
#include <linux/export.h>
#include <linux/kexec.h>
#include <linux/kmod.h>
#include <linux/kmsg_dump.h>
#include <linux/reboot.h>
#include <linux/suspend.h>
#include <linux/syscalls.h>
#include <linux/syscore_ops.h>
#include <linux/uaccess.h>

/*
 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
 */

int C_A_D = 1;
struct pid *cad_pid;
EXPORT_SYMBOL(cad_pid);

#if defined(CONFIG_ARM) || defined(CONFIG_UNICORE32)
#define DEFAULT_REBOOT_MODE		= REBOOT_HARD
#else
#define DEFAULT_REBOOT_MODE
#endif
enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE;

/*
 * This variable is used privately to keep track of whether or not
 * reboot_type is still set to its default value (i.e., reboot= hasn't
 * been set on the command line).  This is needed so that we can
 * suppress DMI scanning for reboot quirks.  Without it, it's
 * impossible to override a faulty reboot quirk without recompiling.
 */
int reboot_default = 1;
int reboot_cpu;
enum reboot_type reboot_type = BOOT_ACPI;
int reboot_force;

/*
 * If set, this is used for preparing the system to power off.
 */

void (*pm_power_off_prepare)(void);

/**
 *	emergency_restart - reboot the system
 *
 *	Without shutting down any hardware or taking any locks
 *	reboot the system.  This is called when we know we are in
 *	trouble so this is our best effort to reboot.  This is
 *	safe to call in interrupt context.
 */
void emergency_restart(void)
{
	kmsg_dump(KMSG_DUMP_EMERG);
	machine_emergency_restart();
}
EXPORT_SYMBOL_GPL(emergency_restart);

void kernel_restart_prepare(char *cmd)
{
	blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
	system_state = SYSTEM_RESTART;
	usermodehelper_disable();
	device_shutdown();
}

/**
 *	register_reboot_notifier - Register function to be called at reboot time
 *	@nb: Info about notifier function to be called
 *
 *	Registers a function with the list of functions
 *	to be called at reboot time.
 *
 *	Currently always returns zero, as blocking_notifier_chain_register()
 *	always returns zero.
 */
int register_reboot_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&reboot_notifier_list, nb);
}
EXPORT_SYMBOL(register_reboot_notifier);

/**
 *	unregister_reboot_notifier - Unregister previously registered reboot notifier
 *	@nb: Hook to be unregistered
 *
 *	Unregisters a previously registered reboot
 *	notifier function.
 *
 *	Returns zero on success, or %-ENOENT on failure.
 */
int unregister_reboot_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_unregister(&reboot_notifier_list, nb);
}
EXPORT_SYMBOL(unregister_reboot_notifier);

void migrate_to_reboot_cpu(void)
{
	/* The boot cpu is always logical cpu 0 */
	int cpu = reboot_cpu;

	cpu_hotplug_disable();

	/* Make certain the cpu I'm about to reboot on is online */
	if (!cpu_online(cpu))
		cpu = cpumask_first(cpu_online_mask);

	/* Prevent races with other tasks migrating this task */
	current->flags |= PF_NO_SETAFFINITY;

	/* Make certain I only run on the appropriate processor */
	set_cpus_allowed_ptr(current, cpumask_of(cpu));
}

/**
 *	kernel_restart - reboot the system
 *	@cmd: pointer to buffer containing command to execute for restart
 *		or %NULL
 *
 *	Shutdown everything and perform a clean reboot.
 *	This is not safe to call in interrupt context.
 */
void kernel_restart(char *cmd)
{
	kernel_restart_prepare(cmd);
	migrate_to_reboot_cpu();
	syscore_shutdown();
	if (!cmd)
		pr_emerg("Restarting system\n");
	else
		pr_emerg("Restarting system with command '%s'\n", cmd);
	kmsg_dump(KMSG_DUMP_RESTART);
	machine_restart(cmd);
}
EXPORT_SYMBOL_GPL(kernel_restart);

static void kernel_shutdown_prepare(enum system_states state)
{
	blocking_notifier_call_chain(&reboot_notifier_list,
		(state == SYSTEM_HALT) ? SYS_HALT : SYS_POWER_OFF, NULL);
	system_state = state;
	usermodehelper_disable();
	device_shutdown();
}
/**
 *	kernel_halt - halt the system
 *
 *	Shutdown everything and perform a clean system halt.
 */
void kernel_halt(void)
{
	kernel_shutdown_prepare(SYSTEM_HALT);
	migrate_to_reboot_cpu();
	syscore_shutdown();
	pr_emerg("System halted\n");
	kmsg_dump(KMSG_DUMP_HALT);
	machine_halt();
}
EXPORT_SYMBOL_GPL(kernel_halt);

/**
 *	kernel_power_off - power_off the system
 *
 *	Shutdown everything and perform a clean system power_off.
 */
void kernel_power_off(void)
{
	kernel_shutdown_prepare(SYSTEM_POWER_OFF);
	if (pm_power_off_prepare)
		pm_power_off_prepare();
	migrate_to_reboot_cpu();
	syscore_shutdown();
	pr_emerg("Power down\n");
	kmsg_dump(KMSG_DUMP_POWEROFF);
	machine_power_off();
}
EXPORT_SYMBOL_GPL(kernel_power_off);

static DEFINE_MUTEX(reboot_mutex);

/*
 * Reboot system call: for obvious reasons only root may call it,
 * and even root needs to set up some magic numbers in the registers
 * so that some mistake won't make this reboot the whole machine.
 * You can also set the meaning of the ctrl-alt-del-key here.
 *
 * reboot doesn't sync: do that yourself before calling this.
 */
SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
		void __user *, arg)
{
	struct pid_namespace *pid_ns = task_active_pid_ns(current);
	char buffer[256];
	int ret = 0;

	/* We only trust the superuser with rebooting the system. */
	if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT))
		return -EPERM;

	/* For safety, we require "magic" arguments. */
	if (magic1 != LINUX_REBOOT_MAGIC1 ||
			(magic2 != LINUX_REBOOT_MAGIC2 &&
			magic2 != LINUX_REBOOT_MAGIC2A &&
			magic2 != LINUX_REBOOT_MAGIC2B &&
			magic2 != LINUX_REBOOT_MAGIC2C))
		return -EINVAL;

	/*
	 * If pid namespaces are enabled and the current task is in a child
	 * pid_namespace, the command is handled by reboot_pid_ns() which will
	 * call do_exit().
	 */
	ret = reboot_pid_ns(pid_ns, cmd);
	if (ret)
		return ret;

	/* Instead of trying to make the power_off code look like
	 * halt when pm_power_off is not set do it the easy way.
	 */
	if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
		cmd = LINUX_REBOOT_CMD_HALT;

	mutex_lock(&reboot_mutex);
	switch (cmd) {
	case LINUX_REBOOT_CMD_RESTART:
		kernel_restart(NULL);
		break;

	case LINUX_REBOOT_CMD_CAD_ON:
		C_A_D = 1;
		break;

	case LINUX_REBOOT_CMD_CAD_OFF:
		C_A_D = 0;
		break;

	case LINUX_REBOOT_CMD_HALT:
		kernel_halt();
		do_exit(0);
		panic("cannot halt");

	case LINUX_REBOOT_CMD_POWER_OFF:
		kernel_power_off();
		do_exit(0);
		break;

	case LINUX_REBOOT_CMD_RESTART2:
		ret = strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1);
		if (ret < 0) {
			ret = -EFAULT;
			break;
		}
		buffer[sizeof(buffer) - 1] = '\0';

		kernel_restart(buffer);
		break;

#ifdef CONFIG_KEXEC
	case LINUX_REBOOT_CMD_KEXEC:
		ret = kernel_kexec();
		break;
#endif

#ifdef CONFIG_HIBERNATION
	case LINUX_REBOOT_CMD_SW_SUSPEND:
		ret = hibernate();
		break;
#endif

	default:
		ret = -EINVAL;
		break;
	}
	mutex_unlock(&reboot_mutex);
	return ret;
}

static void deferred_cad(struct work_struct *dummy)
{
	kernel_restart(NULL);
}

/*
 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
 * As it's called within an interrupt, it may NOT sync: the only choice
 * is whether to reboot at once, or just ignore the ctrl-alt-del.
 */
void ctrl_alt_del(void)
{
	static DECLARE_WORK(cad_work, deferred_cad);

	if (C_A_D)
		schedule_work(&cad_work);
	else
		kill_cad_pid(SIGINT, 1);
}

char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";

static int __orderly_poweroff(bool force)
{
	char **argv;
	static char *envp[] = {
		"HOME=/",
		"PATH=/sbin:/bin:/usr/sbin:/usr/bin",
		NULL
	};
	int ret;

	argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL);
	if (argv) {
		ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
		argv_free(argv);
	} else {
		ret = -ENOMEM;
	}

	if (ret && force) {
		pr_warn("Failed to start orderly shutdown: forcing the issue\n");
		/*
		 * I guess this should try to kick off some daemon to sync and
		 * poweroff asap.  Or not even bother syncing if we're doing an
		 * emergency shutdown?
		 */
		emergency_sync();
		kernel_power_off();
	}

	return ret;
}

static bool poweroff_force;

static void poweroff_work_func(struct work_struct *work)
{
	__orderly_poweroff(poweroff_force);
}

static DECLARE_WORK(poweroff_work, poweroff_work_func);

/**
 * orderly_poweroff - Trigger an orderly system poweroff
 * @force: force poweroff if command execution fails
 *
 * This may be called from any context to trigger a system shutdown.
 * If the orderly shutdown fails, it will force an immediate shutdown.
 */
int orderly_poweroff(bool force)
{
	if (force) /* do not override the pending "true" */
		poweroff_force = true;
	schedule_work(&poweroff_work);
	return 0;
}
EXPORT_SYMBOL_GPL(orderly_poweroff);

static int __init reboot_setup(char *str)
{
	for (;;) {
		/*
		 * Having anything passed on the command line via
		 * reboot= will cause us to disable DMI checking
		 * below.
		 */
		reboot_default = 0;

		switch (*str) {
		case 'w':
			reboot_mode = REBOOT_WARM;
			break;

		case 'c':
			reboot_mode = REBOOT_COLD;
			break;

		case 'h':
			reboot_mode = REBOOT_HARD;
			break;

		case 's':
		{
			int rc;

			if (isdigit(*(str+1))) {
				rc = kstrtoint(str+1, 0, &reboot_cpu);
				if (rc)
					return rc;
			} else if (str[1] == 'm' && str[2] == 'p' &&
				   isdigit(*(str+3))) {
				rc = kstrtoint(str+3, 0, &reboot_cpu);
				if (rc)
					return rc;
			} else
				reboot_mode = REBOOT_SOFT;
			break;
		}
		case 'g':
			reboot_mode = REBOOT_GPIO;
			break;

		case 'b':
		case 'a':
		case 'k':
		case 't':
		case 'e':
		case 'p':
			reboot_type = *str;
			break;

		case 'f':
			reboot_force = 1;
			break;
		}

		str = strchr(str, ',');
		if (str)
			str++;
		else
			break;
	}
	return 1;
}
__setup("reboot=", reboot_setup);
Commit	Line	Data
15d94b82 RH	1	/*
	2	* linux/kernel/reboot.c
	3	*
	4	* Copyright (C) 2013 Linus Torvalds
	5	*/
	6
972ee83d RH	7	#define pr_fmt(fmt) "reboot: " fmt
972ee83d RH	8
1b3a5d02	9	#include <linux/ctype.h>
15d94b82 RH	10	#include <linux/export.h>
	11	#include <linux/kexec.h>
	12	#include <linux/kmod.h>
	13	#include <linux/kmsg_dump.h>
	14	#include <linux/reboot.h>
	15	#include <linux/suspend.h>
	16	#include <linux/syscalls.h>
	17	#include <linux/syscore_ops.h>
	18	#include <linux/uaccess.h>
	19
	20	/*
	21	* this indicates whether you can reboot with ctrl-alt-del: the default is yes
	22	*/
	23
	24	int C_A_D = 1;
	25	struct pid *cad_pid;
	26	EXPORT_SYMBOL(cad_pid);
	27
1b3a5d02 RH	28	#if defined(CONFIG_ARM) \|\| defined(CONFIG_UNICORE32)
	29	#define DEFAULT_REBOOT_MODE = REBOOT_HARD
	30	#else
	31	#define DEFAULT_REBOOT_MODE
	32	#endif
	33	enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE;
	34
e2f0b88e CL	35	/*
	36	* This variable is used privately to keep track of whether or not
	37	* reboot_type is still set to its default value (i.e., reboot= hasn't
	38	* been set on the command line). This is needed so that we can
	39	* suppress DMI scanning for reboot quirks. Without it, it's
	40	* impossible to override a faulty reboot quirk without recompiling.
	41	*/
	42	int reboot_default = 1;
1b3a5d02 RH	43	int reboot_cpu;
	44	enum reboot_type reboot_type = BOOT_ACPI;
	45	int reboot_force;
	46
15d94b82 RH	47	/*
	48	* If set, this is used for preparing the system to power off.
	49	*/
	50
	51	void (*pm_power_off_prepare)(void);
	52
	53	/**
	54	* emergency_restart - reboot the system
	55	*
	56	* Without shutting down any hardware or taking any locks
	57	* reboot the system. This is called when we know we are in
	58	* trouble so this is our best effort to reboot. This is
	59	* safe to call in interrupt context.
	60	*/
	61	void emergency_restart(void)
	62	{
	63	kmsg_dump(KMSG_DUMP_EMERG);
	64	machine_emergency_restart();
	65	}
	66	EXPORT_SYMBOL_GPL(emergency_restart);
	67
	68	void kernel_restart_prepare(char *cmd)
	69	{
	70	blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
	71	system_state = SYSTEM_RESTART;
	72	usermodehelper_disable();
	73	device_shutdown();
	74	}
	75
	76	/**
	77	* register_reboot_notifier - Register function to be called at reboot time
	78	* @nb: Info about notifier function to be called
	79	*
	80	* Registers a function with the list of functions
	81	* to be called at reboot time.
	82	*
	83	* Currently always returns zero, as blocking_notifier_chain_register()
	84	* always returns zero.
	85	*/
	86	int register_reboot_notifier(struct notifier_block *nb)
	87	{
	88	return blocking_notifier_chain_register(&reboot_notifier_list, nb);
	89	}
	90	EXPORT_SYMBOL(register_reboot_notifier);
	91
	92	/**
	93	* unregister_reboot_notifier - Unregister previously registered reboot notifier
	94	* @nb: Hook to be unregistered
	95	*
	96	* Unregisters a previously registered reboot
	97	* notifier function.
	98	*
	99	* Returns zero on success, or %-ENOENT on failure.
	100	*/
	101	int unregister_reboot_notifier(struct notifier_block *nb)
	102	{
	103	return blocking_notifier_chain_unregister(&reboot_notifier_list, nb);
	104	}
	105	EXPORT_SYMBOL(unregister_reboot_notifier);
	106
c97102ba	107	void migrate_to_reboot_cpu(void)
15d94b82 RH	108	{
15d94b82 RH	109	/* The boot cpu is always logical cpu 0 */
1b3a5d02	110	int cpu = reboot_cpu;
15d94b82 RH	111
	112	cpu_hotplug_disable();
	113
	114	/* Make certain the cpu I'm about to reboot on is online */
	115	if (!cpu_online(cpu))
	116	cpu = cpumask_first(cpu_online_mask);
	117
	118	/* Prevent races with other tasks migrating this task */
	119	current->flags \|= PF_NO_SETAFFINITY;
	120
	121	/* Make certain I only run on the appropriate processor */
	122	set_cpus_allowed_ptr(current, cpumask_of(cpu));
	123	}
	124
	125	/**
	126	* kernel_restart - reboot the system
	127	* @cmd: pointer to buffer containing command to execute for restart
	128	* or %NULL
	129	*
	130	* Shutdown everything and perform a clean reboot.
	131	* This is not safe to call in interrupt context.
	132	*/
	133	void kernel_restart(char *cmd)
	134	{
	135	kernel_restart_prepare(cmd);
	136	migrate_to_reboot_cpu();
	137	syscore_shutdown();
	138	if (!cmd)
972ee83d	139	pr_emerg("Restarting system\n");
15d94b82	140	else
972ee83d	141	pr_emerg("Restarting system with command '%s'\n", cmd);
15d94b82 RH	142	kmsg_dump(KMSG_DUMP_RESTART);
	143	machine_restart(cmd);
	144	}
	145	EXPORT_SYMBOL_GPL(kernel_restart);
	146
	147	static void kernel_shutdown_prepare(enum system_states state)
	148	{
	149	blocking_notifier_call_chain(&reboot_notifier_list,
972ee83d	150	(state == SYSTEM_HALT) ? SYS_HALT : SYS_POWER_OFF, NULL);
15d94b82 RH	151	system_state = state;
	152	usermodehelper_disable();
	153	device_shutdown();
	154	}
	155	/**
	156	* kernel_halt - halt the system
	157	*
	158	* Shutdown everything and perform a clean system halt.
	159	*/
	160	void kernel_halt(void)
	161	{
	162	kernel_shutdown_prepare(SYSTEM_HALT);
	163	migrate_to_reboot_cpu();
	164	syscore_shutdown();
972ee83d	165	pr_emerg("System halted\n");
15d94b82 RH	166	kmsg_dump(KMSG_DUMP_HALT);
	167	machine_halt();
	168	}
15d94b82 RH	169	EXPORT_SYMBOL_GPL(kernel_halt);
	170
	171	/**
	172	* kernel_power_off - power_off the system
	173	*
	174	* Shutdown everything and perform a clean system power_off.
	175	*/
	176	void kernel_power_off(void)
	177	{
	178	kernel_shutdown_prepare(SYSTEM_POWER_OFF);
	179	if (pm_power_off_prepare)
	180	pm_power_off_prepare();
	181	migrate_to_reboot_cpu();
	182	syscore_shutdown();
972ee83d	183	pr_emerg("Power down\n");
15d94b82 RH	184	kmsg_dump(KMSG_DUMP_POWEROFF);
	185	machine_power_off();
	186	}
	187	EXPORT_SYMBOL_GPL(kernel_power_off);
	188
	189	static DEFINE_MUTEX(reboot_mutex);
	190
	191	/*
	192	* Reboot system call: for obvious reasons only root may call it,
	193	* and even root needs to set up some magic numbers in the registers
	194	* so that some mistake won't make this reboot the whole machine.
	195	* You can also set the meaning of the ctrl-alt-del-key here.
	196	*
	197	* reboot doesn't sync: do that yourself before calling this.
	198	*/
	199	SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
	200	void __user *, arg)
	201	{
	202	struct pid_namespace *pid_ns = task_active_pid_ns(current);
	203	char buffer[256];
	204	int ret = 0;
	205
	206	/* We only trust the superuser with rebooting the system. */
	207	if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT))
	208	return -EPERM;
	209
	210	/* For safety, we require "magic" arguments. */
	211	if (magic1 != LINUX_REBOOT_MAGIC1 \|\|
972ee83d RH	212	(magic2 != LINUX_REBOOT_MAGIC2 &&
972ee83d RH	213	magic2 != LINUX_REBOOT_MAGIC2A &&
15d94b82	214	magic2 != LINUX_REBOOT_MAGIC2B &&
972ee83d	215	magic2 != LINUX_REBOOT_MAGIC2C))
15d94b82 RH	216	return -EINVAL;
	217
	218	/*
	219	* If pid namespaces are enabled and the current task is in a child
	220	* pid_namespace, the command is handled by reboot_pid_ns() which will
	221	* call do_exit().
	222	*/
	223	ret = reboot_pid_ns(pid_ns, cmd);
	224	if (ret)
	225	return ret;
	226
	227	/* Instead of trying to make the power_off code look like
	228	* halt when pm_power_off is not set do it the easy way.
	229	*/
	230	if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
	231	cmd = LINUX_REBOOT_CMD_HALT;
	232
	233	mutex_lock(&reboot_mutex);
	234	switch (cmd) {
	235	case LINUX_REBOOT_CMD_RESTART:
	236	kernel_restart(NULL);
	237	break;
	238
	239	case LINUX_REBOOT_CMD_CAD_ON:
	240	C_A_D = 1;
	241	break;
	242
	243	case LINUX_REBOOT_CMD_CAD_OFF:
	244	C_A_D = 0;
	245	break;
	246
	247	case LINUX_REBOOT_CMD_HALT:
	248	kernel_halt();
	249	do_exit(0);
	250	panic("cannot halt");
	251
	252	case LINUX_REBOOT_CMD_POWER_OFF:
	253	kernel_power_off();
	254	do_exit(0);
	255	break;
	256
	257	case LINUX_REBOOT_CMD_RESTART2:
972ee83d RH	258	ret = strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1);
972ee83d RH	259	if (ret < 0) {
15d94b82 RH	260	ret = -EFAULT;
	261	break;
	262	}
	263	buffer[sizeof(buffer) - 1] = '\0';
	264
	265	kernel_restart(buffer);
	266	break;
	267
	268	#ifdef CONFIG_KEXEC
	269	case LINUX_REBOOT_CMD_KEXEC:
	270	ret = kernel_kexec();
	271	break;
	272	#endif
	273
	274	#ifdef CONFIG_HIBERNATION
	275	case LINUX_REBOOT_CMD_SW_SUSPEND:
	276	ret = hibernate();
	277	break;
	278	#endif
	279
	280	default:
	281	ret = -EINVAL;
	282	break;
	283	}
	284	mutex_unlock(&reboot_mutex);
	285	return ret;
	286	}
	287
	288	static void deferred_cad(struct work_struct *dummy)
	289	{
	290	kernel_restart(NULL);
	291	}
	292
	293	/*
	294	* This function gets called by ctrl-alt-del - ie the keyboard interrupt.
	295	* As it's called within an interrupt, it may NOT sync: the only choice
	296	* is whether to reboot at once, or just ignore the ctrl-alt-del.
	297	*/
	298	void ctrl_alt_del(void)
	299	{
	300	static DECLARE_WORK(cad_work, deferred_cad);
	301
	302	if (C_A_D)
	303	schedule_work(&cad_work);
	304	else
	305	kill_cad_pid(SIGINT, 1);
	306	}
	307
	308	char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
	309
	310	static int __orderly_poweroff(bool force)
	311	{
	312	char **argv;
	313	static char *envp[] = {
	314	"HOME=/",
	315	"PATH=/sbin:/bin:/usr/sbin:/usr/bin",
	316	NULL
	317	};
	318	int ret;
	319
	320	argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL);
	321	if (argv) {
	322	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
	323	argv_free(argv);
324	} else {
15d94b82 RH	325	ret = -ENOMEM;
	326	}
	327
	328	if (ret && force) {
972ee83d	329	pr_warn("Failed to start orderly shutdown: forcing the issue\n");
15d94b82 RH	330	/*
	331	* I guess this should try to kick off some daemon to sync and
	332	* poweroff asap. Or not even bother syncing if we're doing an
	333	* emergency shutdown?
	334	*/
	335	emergency_sync();
	336	kernel_power_off();
	337	}
	338
	339	return ret;
	340	}
	341
	342	static bool poweroff_force;
	343
	344	static void poweroff_work_func(struct work_struct *work)
	345	{
	346	__orderly_poweroff(poweroff_force);
	347	}
	348
	349	static DECLARE_WORK(poweroff_work, poweroff_work_func);
	350
	351	/**
	352	* orderly_poweroff - Trigger an orderly system poweroff
	353	* @force: force poweroff if command execution fails
	354	*
	355	* This may be called from any context to trigger a system shutdown.
	356	* If the orderly shutdown fails, it will force an immediate shutdown.
	357	*/
	358	int orderly_poweroff(bool force)
	359	{
	360	if (force) /* do not override the pending "true" */
	361	poweroff_force = true;
	362	schedule_work(&poweroff_work);
	363	return 0;
	364	}
	365	EXPORT_SYMBOL_GPL(orderly_poweroff);
1b3a5d02 RH	366
	367	static int __init reboot_setup(char *str)
	368	{
	369	for (;;) {
	370	/*
	371	* Having anything passed on the command line via
	372	* reboot= will cause us to disable DMI checking
	373	* below.
	374	*/
	375	reboot_default = 0;
	376
	377	switch (*str) {
	378	case 'w':
	379	reboot_mode = REBOOT_WARM;
	380	break;
	381
	382	case 'c':
	383	reboot_mode = REBOOT_COLD;
	384	break;
	385
	386	case 'h':
	387	reboot_mode = REBOOT_HARD;
	388	break;
	389
	390	case 's':
616feab7 FF	391	{
	392	int rc;
	393
	394	if (isdigit(*(str+1))) {
	395	rc = kstrtoint(str+1, 0, &reboot_cpu);
	396	if (rc)
	397	return rc;
	398	} else if (str[1] == 'm' && str[2] == 'p' &&
	399	isdigit(*(str+3))) {
	400	rc = kstrtoint(str+3, 0, &reboot_cpu);
	401	if (rc)
	402	return rc;
	403	} else
1b3a5d02 RH	404	reboot_mode = REBOOT_SOFT;
1b3a5d02 RH	405	break;
616feab7	406	}
1b3a5d02 RH	407	case 'g':
	408	reboot_mode = REBOOT_GPIO;
	409	break;
	410
	411	case 'b':
	412	case 'a':
	413	case 'k':
	414	case 't':
	415	case 'e':
	416	case 'p':
	417	reboot_type = *str;
	418	break;
	419
	420	case 'f':
	421	reboot_force = 1;
	422	break;
	423	}
	424
	425	str = strchr(str, ',');
	426	if (str)
	427	str++;
	428	else
	429	break;
	430	}
	431	return 1;
	432	}
	433	__setup("reboot=", reboot_setup);