[deliverable/linux.git] / arch / powerpc / kernel / crash.c

/*
 * Architecture specific (PPC64) functions for kexec based crash dumps.
 *
 * Copyright (C) 2005, IBM Corp.
 *
 * Created by: Haren Myneni
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 *
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/kexec.h>
#include <linux/bootmem.h>
#include <linux/export.h>
#include <linux/crash_dump.h>
#include <linux/delay.h>
#include <linux/elf.h>
#include <linux/elfcore.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/types.h>
#include <linux/memblock.h>

#include <asm/processor.h>
#include <asm/machdep.h>
#include <asm/kexec.h>
#include <asm/kdump.h>
#include <asm/prom.h>
#include <asm/firmware.h>
#include <asm/smp.h>
#include <asm/system.h>
#include <asm/setjmp.h>

#ifdef DEBUG
#include <asm/udbg.h>
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif

/* This keeps a track of which one is crashing cpu. */
int crashing_cpu = -1;
static cpumask_t cpus_in_crash = CPU_MASK_NONE;
cpumask_t cpus_in_sr = CPU_MASK_NONE;

#define CRASH_HANDLER_MAX 3
/* NULL terminated list of shutdown handles */
static crash_shutdown_t crash_shutdown_handles[CRASH_HANDLER_MAX+1];
static DEFINE_SPINLOCK(crash_handlers_lock);

#ifdef CONFIG_SMP
static atomic_t enter_on_soft_reset = ATOMIC_INIT(0);

void crash_ipi_callback(struct pt_regs *regs)
{
	int cpu = smp_processor_id();

	if (!cpu_online(cpu))
		return;

	hard_irq_disable();
	if (!cpumask_test_cpu(cpu, &cpus_in_crash))
		crash_save_cpu(regs, cpu);
	cpumask_set_cpu(cpu, &cpus_in_crash);

	/*
	 * Entered via soft-reset - could be the kdump
	 * process is invoked using soft-reset or user activated
	 * it if some CPU did not respond to an IPI.
	 * For soft-reset, the secondary CPU can enter this func
	 * twice. 1 - using IPI, and 2. soft-reset.
	 * Tell the kexec CPU that entered via soft-reset and ready
	 * to go down.
	 */
	if (cpumask_test_cpu(cpu, &cpus_in_sr)) {
		cpumask_clear_cpu(cpu, &cpus_in_sr);
		atomic_inc(&enter_on_soft_reset);
	}

	/*
	 * Starting the kdump boot.
	 * This barrier is needed to make sure that all CPUs are stopped.
	 * If not, soft-reset will be invoked to bring other CPUs.
	 */
	while (!cpumask_test_cpu(crashing_cpu, &cpus_in_crash))
		cpu_relax();

	if (ppc_md.kexec_cpu_down)
		ppc_md.kexec_cpu_down(1, 1);

#ifdef CONFIG_PPC64
	kexec_smp_wait();
#else
	for (;;);	/* FIXME */
#endif

	/* NOTREACHED */
}

/*
 * Wait until all CPUs are entered via soft-reset.
 */
static void crash_soft_reset_check(int cpu)
{
	unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */

	cpumask_clear_cpu(cpu, &cpus_in_sr);
	while (atomic_read(&enter_on_soft_reset) != ncpus)
		cpu_relax();
}


static void crash_kexec_prepare_cpus(int cpu)
{
	unsigned int msecs;

	unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */

	crash_send_ipi(crash_ipi_callback);
	smp_wmb();

	/*
	 * FIXME: Until we will have the way to stop other CPUs reliably,
	 * the crash CPU will send an IPI and wait for other CPUs to
	 * respond.
	 * Delay of at least 10 seconds.
	 */
	printk(KERN_EMERG "Sending IPI to other cpus...\n");
	msecs = 10000;
	while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
		cpu_relax();
		mdelay(1);
	}

	/* Would it be better to replace the trap vector here? */

	/*
	 * FIXME: In case if we do not get all CPUs, one possibility: ask the
	 * user to do soft reset such that we get all.
	 * Soft-reset will be used until better mechanism is implemented.
	 */
	if (cpumask_weight(&cpus_in_crash) < ncpus) {
		printk(KERN_EMERG "done waiting: %d cpu(s) not responding\n",
			ncpus - cpumask_weight(&cpus_in_crash));
		printk(KERN_EMERG "Activate soft-reset to stop other cpu(s)\n");
		cpumask_clear(&cpus_in_sr);
		atomic_set(&enter_on_soft_reset, 0);
		while (cpumask_weight(&cpus_in_crash) < ncpus)
			cpu_relax();
	}
	/*
	 * Make sure all CPUs are entered via soft-reset if the kdump is
	 * invoked using soft-reset.
	 */
	if (cpumask_test_cpu(cpu, &cpus_in_sr))
		crash_soft_reset_check(cpu);
	/* Leave the IPI callback set */
}

/*
 * This function will be called by secondary cpus or by kexec cpu
 * if soft-reset is activated to stop some CPUs.
 */
void crash_kexec_secondary(struct pt_regs *regs)
{
	int cpu = smp_processor_id();
	unsigned long flags;
	int msecs = 5;

	local_irq_save(flags);
	/* Wait 5ms if the kexec CPU is not entered yet. */
	while (crashing_cpu < 0) {
		if (--msecs < 0) {
			/*
			 * Either kdump image is not loaded or
			 * kdump process is not started - Probably xmon
			 * exited using 'x'(exit and recover) or
			 * kexec_should_crash() failed for all running tasks.
			 */
			cpumask_clear_cpu(cpu, &cpus_in_sr);
			local_irq_restore(flags);
			return;
		}
		mdelay(1);
		cpu_relax();
	}
	if (cpu == crashing_cpu) {
		/*
		 * Panic CPU will enter this func only via soft-reset.
		 * Wait until all secondary CPUs entered and
		 * then start kexec boot.
		 */
		crash_soft_reset_check(cpu);
		cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
		if (ppc_md.kexec_cpu_down)
			ppc_md.kexec_cpu_down(1, 0);
		machine_kexec(kexec_crash_image);
		/* NOTREACHED */
	}
	crash_ipi_callback(regs);
}

#else	/* ! CONFIG_SMP */

static void crash_kexec_prepare_cpus(int cpu)
{
	/*
	 * move the secondarys to us so that we can copy
	 * the new kernel 0-0x100 safely
	 *
	 * do this if kexec in setup.c ?
	 */
#ifdef CONFIG_PPC64
	smp_release_cpus();
#else
	/* FIXME */
#endif
}

void crash_kexec_secondary(struct pt_regs *regs)
{
	cpumask_clear(&cpus_in_sr);
}
#endif	/* CONFIG_SMP */

/* wait for all the CPUs to hit real mode but timeout if they don't come in */
#if defined(CONFIG_SMP) && defined(CONFIG_PPC_STD_MMU_64)
static void crash_kexec_wait_realmode(int cpu)
{
	unsigned int msecs;
	int i;

	msecs = 10000;
	for (i=0; i < nr_cpu_ids && msecs > 0; i++) {
		if (i == cpu)
			continue;

		while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
			barrier();
			if (!cpu_possible(i) || !cpu_online(i) || (msecs <= 0))
				break;
			msecs--;
			mdelay(1);
		}
	}
	mb();
}
#else
static inline void crash_kexec_wait_realmode(int cpu) {}
#endif	/* CONFIG_SMP && CONFIG_PPC_STD_MMU_64 */

/*
 * Register a function to be called on shutdown.  Only use this if you
 * can't reset your device in the second kernel.
 */
int crash_shutdown_register(crash_shutdown_t handler)
{
	unsigned int i, rc;

	spin_lock(&crash_handlers_lock);
	for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
		if (!crash_shutdown_handles[i]) {
			/* Insert handle at first empty entry */
			crash_shutdown_handles[i] = handler;
			rc = 0;
			break;
		}

	if (i == CRASH_HANDLER_MAX) {
		printk(KERN_ERR "Crash shutdown handles full, "
		       "not registered.\n");
		rc = 1;
	}

	spin_unlock(&crash_handlers_lock);
	return rc;
}
EXPORT_SYMBOL(crash_shutdown_register);

int crash_shutdown_unregister(crash_shutdown_t handler)
{
	unsigned int i, rc;

	spin_lock(&crash_handlers_lock);
	for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
		if (crash_shutdown_handles[i] == handler)
			break;

	if (i == CRASH_HANDLER_MAX) {
		printk(KERN_ERR "Crash shutdown handle not found\n");
		rc = 1;
	} else {
		/* Shift handles down */
		for (; crash_shutdown_handles[i]; i++)
			crash_shutdown_handles[i] =
				crash_shutdown_handles[i+1];
		rc = 0;
	}

	spin_unlock(&crash_handlers_lock);
	return rc;
}
EXPORT_SYMBOL(crash_shutdown_unregister);

static unsigned long crash_shutdown_buf[JMP_BUF_LEN];
static int crash_shutdown_cpu = -1;

static int handle_fault(struct pt_regs *regs)
{
	if (crash_shutdown_cpu == smp_processor_id())
		longjmp(crash_shutdown_buf, 1);
	return 0;
}

void default_machine_crash_shutdown(struct pt_regs *regs)
{
	unsigned int i;
	int (*old_handler)(struct pt_regs *regs);


	/*
	 * This function is only called after the system
	 * has panicked or is otherwise in a critical state.
	 * The minimum amount of code to allow a kexec'd kernel
	 * to run successfully needs to happen here.
	 *
	 * In practice this means stopping other cpus in
	 * an SMP system.
	 * The kernel is broken so disable interrupts.
	 */
	hard_irq_disable();

	/*
	 * Make a note of crashing cpu. Will be used in machine_kexec
	 * such that another IPI will not be sent.
	 */
	crashing_cpu = smp_processor_id();
	crash_save_cpu(regs, crashing_cpu);
	crash_kexec_prepare_cpus(crashing_cpu);
	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
	crash_kexec_wait_realmode(crashing_cpu);

	machine_kexec_mask_interrupts();

	/*
	 * Call registered shutdown routines savely.  Swap out
	 * __debugger_fault_handler, and replace on exit.
	 */
	old_handler = __debugger_fault_handler;
	__debugger_fault_handler = handle_fault;
	crash_shutdown_cpu = smp_processor_id();
	for (i = 0; crash_shutdown_handles[i]; i++) {
		if (setjmp(crash_shutdown_buf) == 0) {
			/*
			 * Insert syncs and delay to ensure
			 * instructions in the dangerous region don't
			 * leak away from this protected region.
			 */
			asm volatile("sync; isync");
			/* dangerous region */
			crash_shutdown_handles[i]();
			asm volatile("sync; isync");
		}
	}
	crash_shutdown_cpu = -1;
	__debugger_fault_handler = old_handler;

	if (ppc_md.kexec_cpu_down)
		ppc_md.kexec_cpu_down(1, 0);
}
Commit	Line	Data
	1	/*
	2	* Architecture specific (PPC64) functions for kexec based crash dumps.
	3	*
	4	* Copyright (C) 2005, IBM Corp.
	5	*
	6	* Created by: Haren Myneni
	7	*
	8	* This source code is licensed under the GNU General Public License,
	9	* Version 2. See the file COPYING for more details.
	10	*
	11	*/
	12
	13	#undef DEBUG
	14
	15	#include <linux/kernel.h>
	16	#include <linux/smp.h>
	17	#include <linux/reboot.h>
	18	#include <linux/kexec.h>
	19	#include <linux/bootmem.h>
	20	#include <linux/export.h>
	21	#include <linux/crash_dump.h>
	22	#include <linux/delay.h>
	23	#include <linux/elf.h>
	24	#include <linux/elfcore.h>
	25	#include <linux/init.h>
	26	#include <linux/irq.h>
	27	#include <linux/types.h>
	28	#include <linux/memblock.h>
	29
	30	#include <asm/processor.h>
	31	#include <asm/machdep.h>
	32	#include <asm/kexec.h>
	33	#include <asm/kdump.h>
	34	#include <asm/prom.h>
	35	#include <asm/firmware.h>
	36	#include <asm/smp.h>
	37	#include <asm/system.h>
	38	#include <asm/setjmp.h>
	39
	40	#ifdef DEBUG
	41	#include <asm/udbg.h>
	42	#define DBG(fmt...) udbg_printf(fmt)
	43	#else
	44	#define DBG(fmt...)
	45	#endif
	46
	47	/* This keeps a track of which one is crashing cpu. */
	48	int crashing_cpu = -1;
	49	static cpumask_t cpus_in_crash = CPU_MASK_NONE;
	50	cpumask_t cpus_in_sr = CPU_MASK_NONE;
	51
	52	#define CRASH_HANDLER_MAX 3
	53	/* NULL terminated list of shutdown handles */
	54	static crash_shutdown_t crash_shutdown_handles[CRASH_HANDLER_MAX+1];
	55	static DEFINE_SPINLOCK(crash_handlers_lock);
	56
	57	#ifdef CONFIG_SMP
	58	static atomic_t enter_on_soft_reset = ATOMIC_INIT(0);
	59
	60	void crash_ipi_callback(struct pt_regs *regs)
	61	{
	62	int cpu = smp_processor_id();
	63
	64	if (!cpu_online(cpu))
	65	return;
	66
	67	hard_irq_disable();
	68	if (!cpumask_test_cpu(cpu, &cpus_in_crash))
	69	crash_save_cpu(regs, cpu);
	70	cpumask_set_cpu(cpu, &cpus_in_crash);
	71
	72	/*
	73	* Entered via soft-reset - could be the kdump
	74	* process is invoked using soft-reset or user activated
	75	* it if some CPU did not respond to an IPI.
	76	* For soft-reset, the secondary CPU can enter this func
	77	* twice. 1 - using IPI, and 2. soft-reset.
	78	* Tell the kexec CPU that entered via soft-reset and ready
	79	* to go down.
	80	*/
	81	if (cpumask_test_cpu(cpu, &cpus_in_sr)) {
	82	cpumask_clear_cpu(cpu, &cpus_in_sr);
	83	atomic_inc(&enter_on_soft_reset);
	84	}
	85
	86	/*
	87	* Starting the kdump boot.
	88	* This barrier is needed to make sure that all CPUs are stopped.
	89	* If not, soft-reset will be invoked to bring other CPUs.
	90	*/
	91	while (!cpumask_test_cpu(crashing_cpu, &cpus_in_crash))
	92	cpu_relax();
	93
	94	if (ppc_md.kexec_cpu_down)
	95	ppc_md.kexec_cpu_down(1, 1);
	96
	97	#ifdef CONFIG_PPC64
	98	kexec_smp_wait();
	99	#else
	100	for (;;); /* FIXME */
	101	#endif
	102
	103	/* NOTREACHED */
	104	}
	105
	106	/*
	107	* Wait until all CPUs are entered via soft-reset.
	108	*/
	109	static void crash_soft_reset_check(int cpu)
	110	{
	111	unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
	112
	113	cpumask_clear_cpu(cpu, &cpus_in_sr);
	114	while (atomic_read(&enter_on_soft_reset) != ncpus)
	115	cpu_relax();
	116	}
	117
	118
	119	static void crash_kexec_prepare_cpus(int cpu)
	120	{
	121	unsigned int msecs;
	122
	123	unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
	124
	125	crash_send_ipi(crash_ipi_callback);
	126	smp_wmb();
	127
	128	/*
	129	* FIXME: Until we will have the way to stop other CPUs reliably,
	130	* the crash CPU will send an IPI and wait for other CPUs to
	131	* respond.
	132	* Delay of at least 10 seconds.
	133	*/
	134	printk(KERN_EMERG "Sending IPI to other cpus...\n");
	135	msecs = 10000;
	136	while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
	137	cpu_relax();
	138	mdelay(1);
	139	}
	140
	141	/* Would it be better to replace the trap vector here? */
	142
	143	/*
	144	* FIXME: In case if we do not get all CPUs, one possibility: ask the
	145	* user to do soft reset such that we get all.
	146	* Soft-reset will be used until better mechanism is implemented.
	147	*/
	148	if (cpumask_weight(&cpus_in_crash) < ncpus) {
	149	printk(KERN_EMERG "done waiting: %d cpu(s) not responding\n",
	150	ncpus - cpumask_weight(&cpus_in_crash));
	151	printk(KERN_EMERG "Activate soft-reset to stop other cpu(s)\n");
	152	cpumask_clear(&cpus_in_sr);
	153	atomic_set(&enter_on_soft_reset, 0);
	154	while (cpumask_weight(&cpus_in_crash) < ncpus)
	155	cpu_relax();
	156	}
	157	/*
	158	* Make sure all CPUs are entered via soft-reset if the kdump is
	159	* invoked using soft-reset.
	160	*/
	161	if (cpumask_test_cpu(cpu, &cpus_in_sr))
	162	crash_soft_reset_check(cpu);
	163	/* Leave the IPI callback set */
	164	}
	165
	166	/*
	167	* This function will be called by secondary cpus or by kexec cpu
	168	* if soft-reset is activated to stop some CPUs.
	169	*/
	170	void crash_kexec_secondary(struct pt_regs *regs)
	171	{
	172	int cpu = smp_processor_id();
	173	unsigned long flags;
	174	int msecs = 5;
	175
	176	local_irq_save(flags);
	177	/* Wait 5ms if the kexec CPU is not entered yet. */
	178	while (crashing_cpu < 0) {
	179	if (--msecs < 0) {
	180	/*
	181	* Either kdump image is not loaded or
	182	* kdump process is not started - Probably xmon
	183	* exited using 'x'(exit and recover) or
	184	* kexec_should_crash() failed for all running tasks.
	185	*/
	186	cpumask_clear_cpu(cpu, &cpus_in_sr);
	187	local_irq_restore(flags);
	188	return;
	189	}
	190	mdelay(1);
	191	cpu_relax();
	192	}
	193	if (cpu == crashing_cpu) {
	194	/*
	195	* Panic CPU will enter this func only via soft-reset.
	196	* Wait until all secondary CPUs entered and
	197	* then start kexec boot.
	198	*/
	199	crash_soft_reset_check(cpu);
	200	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
	201	if (ppc_md.kexec_cpu_down)
	202	ppc_md.kexec_cpu_down(1, 0);
	203	machine_kexec(kexec_crash_image);
	204	/* NOTREACHED */
	205	}
	206	crash_ipi_callback(regs);
	207	}
	208
	209	#else /* ! CONFIG_SMP */
	210
	211	static void crash_kexec_prepare_cpus(int cpu)
	212	{
	213	/*
	214	* move the secondarys to us so that we can copy
	215	* the new kernel 0-0x100 safely
	216	*
	217	* do this if kexec in setup.c ?
	218	*/
	219	#ifdef CONFIG_PPC64
	220	smp_release_cpus();
	221	#else
	222	/* FIXME */
	223	#endif
	224	}
	225
	226	void crash_kexec_secondary(struct pt_regs *regs)
	227	{
	228	cpumask_clear(&cpus_in_sr);
	229	}
	230	#endif /* CONFIG_SMP */
	231
	232	/* wait for all the CPUs to hit real mode but timeout if they don't come in */
	233	#if defined(CONFIG_SMP) && defined(CONFIG_PPC_STD_MMU_64)
	234	static void crash_kexec_wait_realmode(int cpu)
	235	{
	236	unsigned int msecs;
	237	int i;
	238
	239	msecs = 10000;
	240	for (i=0; i < nr_cpu_ids && msecs > 0; i++) {
	241	if (i == cpu)
	242	continue;
	243
	244	while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
	245	barrier();
	246	if (!cpu_possible(i) \|\| !cpu_online(i) \|\| (msecs <= 0))
	247	break;
	248	msecs--;
	249	mdelay(1);
	250	}
	251	}
	252	mb();
	253	}
	254	#else
	255	static inline void crash_kexec_wait_realmode(int cpu) {}
	256	#endif /* CONFIG_SMP && CONFIG_PPC_STD_MMU_64 */
	257
	258	/*
	259	* Register a function to be called on shutdown. Only use this if you
	260	* can't reset your device in the second kernel.
	261	*/
	262	int crash_shutdown_register(crash_shutdown_t handler)
	263	{
	264	unsigned int i, rc;
	265
	266	spin_lock(&crash_handlers_lock);
	267	for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
	268	if (!crash_shutdown_handles[i]) {
	269	/* Insert handle at first empty entry */
	270	crash_shutdown_handles[i] = handler;
	271	rc = 0;
	272	break;
	273	}
	274
	275	if (i == CRASH_HANDLER_MAX) {
	276	printk(KERN_ERR "Crash shutdown handles full, "
	277	"not registered.\n");
	278	rc = 1;
	279	}
	280
	281	spin_unlock(&crash_handlers_lock);
	282	return rc;
	283	}
	284	EXPORT_SYMBOL(crash_shutdown_register);
	285
	286	int crash_shutdown_unregister(crash_shutdown_t handler)
	287	{
	288	unsigned int i, rc;
	289
	290	spin_lock(&crash_handlers_lock);
	291	for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
	292	if (crash_shutdown_handles[i] == handler)
	293	break;
	294
	295	if (i == CRASH_HANDLER_MAX) {
	296	printk(KERN_ERR "Crash shutdown handle not found\n");
	297	rc = 1;
	298	} else {
	299	/* Shift handles down */
	300	for (; crash_shutdown_handles[i]; i++)
	301	crash_shutdown_handles[i] =
	302	crash_shutdown_handles[i+1];
	303	rc = 0;
	304	}
	305
	306	spin_unlock(&crash_handlers_lock);
	307	return rc;
	308	}
	309	EXPORT_SYMBOL(crash_shutdown_unregister);
	310
	311	static unsigned long crash_shutdown_buf[JMP_BUF_LEN];
	312	static int crash_shutdown_cpu = -1;
	313
	314	static int handle_fault(struct pt_regs *regs)
	315	{
	316	if (crash_shutdown_cpu == smp_processor_id())
	317	longjmp(crash_shutdown_buf, 1);
	318	return 0;
	319	}
	320
	321	void default_machine_crash_shutdown(struct pt_regs *regs)
	322	{
	323	unsigned int i;
	324	int (old_handler)(struct pt_regs regs);
	325
	326
	327	/*
	328	* This function is only called after the system
	329	* has panicked or is otherwise in a critical state.
	330	* The minimum amount of code to allow a kexec'd kernel
	331	* to run successfully needs to happen here.
	332	*
	333	* In practice this means stopping other cpus in
	334	* an SMP system.
	335	* The kernel is broken so disable interrupts.
	336	*/
	337	hard_irq_disable();
	338
	339	/*
	340	* Make a note of crashing cpu. Will be used in machine_kexec
	341	* such that another IPI will not be sent.
	342	*/
	343	crashing_cpu = smp_processor_id();
	344	crash_save_cpu(regs, crashing_cpu);
	345	crash_kexec_prepare_cpus(crashing_cpu);
	346	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
	347	crash_kexec_wait_realmode(crashing_cpu);
	348
	349	machine_kexec_mask_interrupts();
	350
	351	/*
	352	* Call registered shutdown routines savely. Swap out
	353	* __debugger_fault_handler, and replace on exit.
	354	*/
	355	old_handler = __debugger_fault_handler;
	356	__debugger_fault_handler = handle_fault;
	357	crash_shutdown_cpu = smp_processor_id();
	358	for (i = 0; crash_shutdown_handles[i]; i++) {
	359	if (setjmp(crash_shutdown_buf) == 0) {
	360	/*
	361	* Insert syncs and delay to ensure
	362	* instructions in the dangerous region don't
	363	* leak away from this protected region.
	364	*/
	365	asm volatile("sync; isync");
	366	/* dangerous region */
	367	crash_shutdown_handles[i]();
	368	asm volatile("sync; isync");
	369	}
	370	}
	371	crash_shutdown_cpu = -1;
	372	__debugger_fault_handler = old_handler;
	373
	374	if (ppc_md.kexec_cpu_down)
	375	ppc_md.kexec_cpu_down(1, 0);
	376	}