[linux-2.6-block.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.
 *
 */

#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/kexec.h>
#include <linux/export.h>
#include <linux/crash_dump.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/types.h>

#include <asm/processor.h>
#include <asm/machdep.h>
#include <asm/kexec.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/setjmp.h>
#include <asm/debug.h>

/*
 * The primary CPU waits a while for all secondary CPUs to enter. This is to
 * avoid sending an IPI if the secondary CPUs are entering
 * crash_kexec_secondary on their own (eg via a system reset).
 *
 * The secondary timeout has to be longer than the primary. Both timeouts are
 * in milliseconds.
 */
#define PRIMARY_TIMEOUT		500
#define SECONDARY_TIMEOUT	1000

#define IPI_TIMEOUT		10000
#define REAL_MODE_TIMEOUT	10000

static int time_to_dump;
/*
 * crash_wake_offline should be set to 1 by platforms that intend to wake
 * up offline cpus prior to jumping to a kdump kernel. Currently powernv
 * sets it to 1, since we want to avoid things from happening when an
 * offline CPU wakes up due to something like an HMI (malfunction error),
 * which propagates to all threads.
 */
int crash_wake_offline;

#define CRASH_HANDLER_MAX 3
/* List of shutdown handles */
static crash_shutdown_t crash_shutdown_handles[CRASH_HANDLER_MAX];
static DEFINE_SPINLOCK(crash_handlers_lock);

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;
}

#ifdef CONFIG_SMP

static atomic_t cpus_in_crash;
void crash_ipi_callback(struct pt_regs *regs)
{
	static cpumask_t cpus_state_saved = CPU_MASK_NONE;

	int cpu = smp_processor_id();

	hard_irq_disable();
	if (!cpumask_test_cpu(cpu, &cpus_state_saved)) {
		crash_save_cpu(regs, cpu);
		cpumask_set_cpu(cpu, &cpus_state_saved);
	}

	atomic_inc(&cpus_in_crash);
	smp_mb__after_atomic();

	/*
	 * Starting the kdump boot.
	 * This barrier is needed to make sure that all CPUs are stopped.
	 */
	while (!time_to_dump)
		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 */
}

static void crash_kexec_prepare_cpus(int cpu)
{
	unsigned int msecs;
	unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
	int tries = 0;
	int (*old_handler)(struct pt_regs *regs);

	printk(KERN_EMERG "Sending IPI to other CPUs\n");

	if (crash_wake_offline)
		ncpus = num_present_cpus() - 1;

	crash_send_ipi(crash_ipi_callback);
	smp_wmb();

again:
	/*
	 * 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.
	 */
	msecs = IPI_TIMEOUT;
	while ((atomic_read(&cpus_in_crash) < ncpus) && (--msecs > 0))
		mdelay(1);

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

	if (atomic_read(&cpus_in_crash) >= ncpus) {
		printk(KERN_EMERG "IPI complete\n");
		return;
	}

	printk(KERN_EMERG "ERROR: %d cpu(s) not responding\n",
		ncpus - atomic_read(&cpus_in_crash));

	/*
	 * If we have a panic timeout set then we can't wait indefinitely
	 * for someone to activate system reset. We also give up on the
	 * second time through if system reset fail to work.
	 */
	if ((panic_timeout > 0) || (tries > 0))
		return;

	/*
	 * A system reset will cause all CPUs to take an 0x100 exception.
	 * The primary CPU returns here via setjmp, and the secondary
	 * CPUs reexecute the crash_kexec_secondary path.
	 */
	old_handler = __debugger;
	__debugger = handle_fault;
	crash_shutdown_cpu = smp_processor_id();

	if (setjmp(crash_shutdown_buf) == 0) {
		printk(KERN_EMERG "Activate system reset (dumprestart) "
				  "to stop other cpu(s)\n");

		/*
		 * A system reset will force all CPUs to execute the
		 * crash code again. We need to reset cpus_in_crash so we
		 * wait for everyone to do this.
		 */
		atomic_set(&cpus_in_crash, 0);
		smp_mb();

		while (atomic_read(&cpus_in_crash) < ncpus)
			cpu_relax();
	}

	crash_shutdown_cpu = -1;
	__debugger = old_handler;

	tries++;
	goto again;
}

/*
 * This function will be called by secondary cpus.
 */
void crash_kexec_secondary(struct pt_regs *regs)
{
	unsigned long flags;
	int msecs = SECONDARY_TIMEOUT;

	local_irq_save(flags);

	/* Wait for the primary crash CPU to signal its progress */
	while (crashing_cpu < 0) {
		if (--msecs < 0) {
			/* No response, kdump image may not have been loaded */
			local_irq_restore(flags);
			return;
		}

		mdelay(1);
	}

	crash_ipi_callback(regs);
}

#else	/* ! CONFIG_SMP */

static void crash_kexec_prepare_cpus(int cpu)
{
	/*
	 * move the secondaries 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)
{
}
#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_PPC64)
static void __maybe_unused crash_kexec_wait_realmode(int cpu)
{
	unsigned int msecs;
	int i;

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

		while (paca_ptrs[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_PPC64 */

/*
 * 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 (; i < (CRASH_HANDLER_MAX - 1); i++)
			crash_shutdown_handles[i] =
				crash_shutdown_handles[i+1];
		/*
		 * Reset last entry to NULL now that it has been shifted down,
		 * this will allow new handles to be added here.
		 */
		crash_shutdown_handles[i] = NULL;
		rc = 0;
	}

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

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();

	/*
	 * If we came in via system reset, wait a while for the secondary
	 * CPUs to enter.
	 */
	if (TRAP(regs) == 0x100)
		mdelay(PRIMARY_TIMEOUT);

	crash_kexec_prepare_cpus(crashing_cpu);

	crash_save_cpu(regs, crashing_cpu);

	time_to_dump = 1;

	crash_kexec_wait_realmode(crashing_cpu);

	machine_kexec_mask_interrupts();

	/*
	 * Call registered shutdown routines safely.  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; i < CRASH_HANDLER_MAX && 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
cc532915 ME	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
cc532915 ME	13	#include <linux/kernel.h>
	14	#include <linux/smp.h>
	15	#include <linux/reboot.h>
	16	#include <linux/kexec.h>
66b15db6	17	#include <linux/export.h>
cc532915	18	#include <linux/crash_dump.h>
cc532915	19	#include <linux/delay.h>
d6c1a908	20	#include <linux/irq.h>
cc532915 ME	21	#include <linux/types.h>
	22
	23	#include <asm/processor.h>
	24	#include <asm/machdep.h>
c0ce7d08	25	#include <asm/kexec.h>
d9b2b2a2	26	#include <asm/prom.h>
f6cc82fc	27	#include <asm/smp.h>
496b010e	28	#include <asm/setjmp.h>
ae3a197e	29	#include <asm/debug.h>
cc532915	30
549e88a1 AB	31	/*
	32	* The primary CPU waits a while for all secondary CPUs to enter. This is to
	33	* avoid sending an IPI if the secondary CPUs are entering
	34	* crash_kexec_secondary on their own (eg via a system reset).
	35	*
	36	* The secondary timeout has to be longer than the primary. Both timeouts are
	37	* in milliseconds.
	38	*/
	39	#define PRIMARY_TIMEOUT 500
	40	#define SECONDARY_TIMEOUT 1000
	41
	42	#define IPI_TIMEOUT 10000
	43	#define REAL_MODE_TIMEOUT 10000
	44
2440c01e	45	static int time_to_dump;
4145f358 BS	46	/*
	47	* crash_wake_offline should be set to 1 by platforms that intend to wake
	48	* up offline cpus prior to jumping to a kdump kernel. Currently powernv
	49	* sets it to 1, since we want to avoid things from happening when an
	50	* offline CPU wakes up due to something like an HMI (malfunction error),
	51	* which propagates to all threads.
	52	*/
	53	int crash_wake_offline;
cc532915	54
158d5b5e	55	#define CRASH_HANDLER_MAX 3
1d145165 SJS	56	/* List of shutdown handles */
1d145165 SJS	57	static crash_shutdown_t crash_shutdown_handles[CRASH_HANDLER_MAX];
496b010e MN	58	static DEFINE_SPINLOCK(crash_handlers_lock);
496b010e MN	59
07fe0c61 AB	60	static unsigned long crash_shutdown_buf[JMP_BUF_LEN];
	61	static int crash_shutdown_cpu = -1;
	62
	63	static int handle_fault(struct pt_regs *regs)
	64	{
	65	if (crash_shutdown_cpu == smp_processor_id())
	66	longjmp(crash_shutdown_buf, 1);
	67	return 0;
	68	}
	69
cc532915	70	#ifdef CONFIG_SMP
cc532915	71
897e01a0	72	static atomic_t cpus_in_crash;
4145f358	73	void crash_ipi_callback(struct pt_regs *regs)
cc532915	74	{
2440c01e AB	75	static cpumask_t cpus_state_saved = CPU_MASK_NONE;
2440c01e AB	76
cc532915 ME	77	int cpu = smp_processor_id();
cc532915 ME	78
d04c56f7	79	hard_irq_disable();
2440c01e	80	if (!cpumask_test_cpu(cpu, &cpus_state_saved)) {
85916f81	81	crash_save_cpu(regs, cpu);
2440c01e AB	82	cpumask_set_cpu(cpu, &cpus_state_saved);
	83	}
	84
	85	atomic_inc(&cpus_in_crash);
c645073f	86	smp_mb__after_atomic();
cc532915	87
c0ce7d08 DW	88	/*
	89	* Starting the kdump boot.
	90	* This barrier is needed to make sure that all CPUs are stopped.
c0ce7d08	91	*/
2440c01e	92	while (!time_to_dump)
c0ce7d08 DW	93	cpu_relax();
	94
	95	if (ppc_md.kexec_cpu_down)
	96	ppc_md.kexec_cpu_down(1, 1);
b6f35b49 ME	97
b6f35b49 ME	98	#ifdef CONFIG_PPC64
cc532915	99	kexec_smp_wait();
b6f35b49 ME	100	#else
	101	for (;;); /* FIXME */
	102	#endif
	103
cc532915 ME	104	/* NOTREACHED */
	105	}
	106
c0ce7d08	107	static void crash_kexec_prepare_cpus(int cpu)
cc532915 ME	108	{
cc532915 ME	109	unsigned int msecs;
c0ce7d08	110	unsigned int ncpus = num_online_cpus() - 1;/* Excluding the panic cpu */
07fe0c61 AB	111	int tries = 0;
07fe0c61 AB	112	int (old_handler)(struct pt_regs regs);
cc532915	113
9b00ac06 AB	114	printk(KERN_EMERG "Sending IPI to other CPUs\n");
9b00ac06 AB	115
4145f358 BS	116	if (crash_wake_offline)
	117	ncpus = num_present_cpus() - 1;
	118
cc532915 ME	119	crash_send_ipi(crash_ipi_callback);
	120	smp_wmb();
	121
07fe0c61	122	again:
cc532915	123	/*
158d5b5e	124	* FIXME: Until we will have the way to stop other CPUs reliably,
cc532915	125	* the crash CPU will send an IPI and wait for other CPUs to
c0ce7d08	126	* respond.
cc532915	127	*/
549e88a1	128	msecs = IPI_TIMEOUT;
2440c01e	129	while ((atomic_read(&cpus_in_crash) < ncpus) && (--msecs > 0))
cc532915	130	mdelay(1);
cc532915 ME	131
	132	/* Would it be better to replace the trap vector here? */
	133
2440c01e	134	if (atomic_read(&cpus_in_crash) >= ncpus) {
07fe0c61 AB	135	printk(KERN_EMERG "IPI complete\n");
07fe0c61 AB	136	return;
c0ce7d08	137	}
9b00ac06	138
07fe0c61	139	printk(KERN_EMERG "ERROR: %d cpu(s) not responding\n",
2440c01e	140	ncpus - atomic_read(&cpus_in_crash));
07fe0c61 AB	141
	142	/*
	143	* If we have a panic timeout set then we can't wait indefinitely
	144	* for someone to activate system reset. We also give up on the
	145	* second time through if system reset fail to work.
	146	*/
	147	if ((panic_timeout > 0) \|\| (tries > 0))
	148	return;
	149
	150	/*
	151	* A system reset will cause all CPUs to take an 0x100 exception.
	152	* The primary CPU returns here via setjmp, and the secondary
	153	* CPUs reexecute the crash_kexec_secondary path.
	154	*/
	155	old_handler = __debugger;
	156	__debugger = handle_fault;
	157	crash_shutdown_cpu = smp_processor_id();
	158
	159	if (setjmp(crash_shutdown_buf) == 0) {
	160	printk(KERN_EMERG "Activate system reset (dumprestart) "
	161	"to stop other cpu(s)\n");
	162
	163	/*
	164	* A system reset will force all CPUs to execute the
	165	* crash code again. We need to reset cpus_in_crash so we
	166	* wait for everyone to do this.
	167	*/
2440c01e	168	atomic_set(&cpus_in_crash, 0);
07fe0c61 AB	169	smp_mb();
07fe0c61 AB	170
2440c01e	171	while (atomic_read(&cpus_in_crash) < ncpus)
07fe0c61 AB	172	cpu_relax();
	173	}
	174
	175	crash_shutdown_cpu = -1;
	176	__debugger = old_handler;
	177
	178	tries++;
	179	goto again;
cc532915	180	}
c0ce7d08 DW	181
c0ce7d08 DW	182	/*
9b00ac06	183	* This function will be called by secondary cpus.
c0ce7d08 DW	184	*/
	185	void crash_kexec_secondary(struct pt_regs *regs)
	186	{
c0ce7d08	187	unsigned long flags;
549e88a1	188	int msecs = SECONDARY_TIMEOUT;
c0ce7d08 DW	189
c0ce7d08 DW	190	local_irq_save(flags);
9b00ac06	191
549e88a1	192	/* Wait for the primary crash CPU to signal its progress */
c0ce7d08 DW	193	while (crashing_cpu < 0) {
c0ce7d08 DW	194	if (--msecs < 0) {
9b00ac06	195	/* No response, kdump image may not have been loaded */
c0ce7d08 DW	196	local_irq_restore(flags);
	197	return;
	198	}
9b00ac06	199
c0ce7d08	200	mdelay(1);
c0ce7d08	201	}
9b00ac06	202
c0ce7d08 DW	203	crash_ipi_callback(regs);
	204	}
	205
7c7a81b5	206	#else /* ! CONFIG_SMP */
7c7a81b5	207
c0ce7d08	208	static void crash_kexec_prepare_cpus(int cpu)
cc532915 ME	209	{
cc532915 ME	210	/*
8c27474a	211	* move the secondaries to us so that we can copy
cc532915 ME	212	* the new kernel 0-0x100 safely
	213	*
	214	* do this if kexec in setup.c ?
	215	*/
b6f35b49	216	#ifdef CONFIG_PPC64
cc532915	217	smp_release_cpus();
b6f35b49 ME	218	#else
	219	/* FIXME */
	220	#endif
cc532915 ME	221	}
cc532915 ME	222
c0ce7d08 DW	223	void crash_kexec_secondary(struct pt_regs *regs)
c0ce7d08 DW	224	{
c0ce7d08	225	}
7c7a81b5	226	#endif /* CONFIG_SMP */
cc532915	227
7707e411	228	/* wait for all the CPUs to hit real mode but timeout if they don't come in */
eeaab663 SW	229	#if defined(CONFIG_SMP) && defined(CONFIG_PPC64)
eeaab663 SW	230	static void __maybe_unused crash_kexec_wait_realmode(int cpu)
7707e411 BH	231	{
	232	unsigned int msecs;
	233	int i;
	234
549e88a1	235	msecs = REAL_MODE_TIMEOUT;
bd9e5eef	236	for (i=0; i < nr_cpu_ids && msecs > 0; i++) {
7707e411 BH	237	if (i == cpu)
	238	continue;
	239
d2e60075	240	while (paca_ptrs[i]->kexec_state < KEXEC_STATE_REAL_MODE) {
7707e411	241	barrier();
63f21a56	242	if (!cpu_possible(i) \|\| !cpu_online(i) \|\| (msecs <= 0))
7707e411	243	break;
7707e411 BH	244	msecs--;
	245	mdelay(1);
	246	}
	247	}
	248	mb();
	249	}
	250	#else
	251	static inline void crash_kexec_wait_realmode(int cpu) {}
eeaab663	252	#endif /* CONFIG_SMP && CONFIG_PPC64 */
7707e411	253
496b010e MN	254	/*
	255	* Register a function to be called on shutdown. Only use this if you
	256	* can't reset your device in the second kernel.
	257	*/
	258	int crash_shutdown_register(crash_shutdown_t handler)
	259	{
	260	unsigned int i, rc;
	261
	262	spin_lock(&crash_handlers_lock);
	263	for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
	264	if (!crash_shutdown_handles[i]) {
	265	/* Insert handle at first empty entry */
	266	crash_shutdown_handles[i] = handler;
	267	rc = 0;
	268	break;
	269	}
	270
	271	if (i == CRASH_HANDLER_MAX) {
	272	printk(KERN_ERR "Crash shutdown handles full, "
	273	"not registered.\n");
	274	rc = 1;
	275	}
	276
	277	spin_unlock(&crash_handlers_lock);
	278	return rc;
	279	}
	280	EXPORT_SYMBOL(crash_shutdown_register);
	281
	282	int crash_shutdown_unregister(crash_shutdown_t handler)
	283	{
	284	unsigned int i, rc;
	285
	286	spin_lock(&crash_handlers_lock);
	287	for (i = 0 ; i < CRASH_HANDLER_MAX; i++)
	288	if (crash_shutdown_handles[i] == handler)
	289	break;
	290
	291	if (i == CRASH_HANDLER_MAX) {
	292	printk(KERN_ERR "Crash shutdown handle not found\n");
	293	rc = 1;
	294	} else {
	295	/* Shift handles down */
1d145165	296	for (; i < (CRASH_HANDLER_MAX - 1); i++)
496b010e MN	297	crash_shutdown_handles[i] =
496b010e MN	298	crash_shutdown_handles[i+1];
1d145165 SJS	299	/*
	300	* Reset last entry to NULL now that it has been shifted down,
	301	* this will allow new handles to be added here.
	302	*/
	303	crash_shutdown_handles[i] = NULL;
496b010e MN	304	rc = 0;
	305	}
	306
	307	spin_unlock(&crash_handlers_lock);
	308	return rc;
	309	}
	310	EXPORT_SYMBOL(crash_shutdown_unregister);
	311
cc532915 ME	312	void default_machine_crash_shutdown(struct pt_regs *regs)
cc532915 ME	313	{
496b010e MN	314	unsigned int i;
	315	int (old_handler)(struct pt_regs regs);
	316
cc532915 ME	317	/*
cc532915 ME	318	* This function is only called after the system
f18190bd	319	* has panicked or is otherwise in a critical state.
cc532915 ME	320	* The minimum amount of code to allow a kexec'd kernel
	321	* to run successfully needs to happen here.
	322	*
	323	* In practice this means stopping other cpus in
	324	* an SMP system.
	325	* The kernel is broken so disable interrupts.
	326	*/
d04c56f7	327	hard_irq_disable();
cc532915	328
249ec228 AB	329	/*
	330	* Make a note of crashing cpu. Will be used in machine_kexec
	331	* such that another IPI will not be sent.
	332	*/
	333	crashing_cpu = smp_processor_id();
549e88a1 AB	334
	335	/*
	336	* If we came in via system reset, wait a while for the secondary
	337	* CPUs to enter.
	338	*/
	339	if (TRAP(regs) == 0x100)
	340	mdelay(PRIMARY_TIMEOUT);
	341
249ec228	342	crash_kexec_prepare_cpus(crashing_cpu);
2440c01e AB	343
	344	crash_save_cpu(regs, crashing_cpu);
	345
	346	time_to_dump = 1;
	347
249ec228	348	crash_kexec_wait_realmode(crashing_cpu);
249ec228	349
c71635d2	350	machine_kexec_mask_interrupts();
496b010e MN	351
496b010e MN	352	/*
8c27474a	353	* Call registered shutdown routines safely. Swap out
496b010e MN	354	* __debugger_fault_handler, and replace on exit.
	355	*/
	356	old_handler = __debugger_fault_handler;
	357	__debugger_fault_handler = handle_fault;
06440794	358	crash_shutdown_cpu = smp_processor_id();
a7d63928	359	for (i = 0; i < CRASH_HANDLER_MAX && crash_shutdown_handles[i]; i++) {
496b010e MN	360	if (setjmp(crash_shutdown_buf) == 0) {
	361	/*
	362	* Insert syncs and delay to ensure
	363	* instructions in the dangerous region don't
	364	* leak away from this protected region.
	365	*/
	366	asm volatile("sync; isync");
	367	/* dangerous region */
	368	crash_shutdown_handles[i]();
	369	asm volatile("sync; isync");
	370	}
d6c1a908	371	}
06440794	372	crash_shutdown_cpu = -1;
496b010e	373	__debugger_fault_handler = old_handler;
d6c1a908	374
c0ce7d08 DW	375	if (ppc_md.kexec_cpu_down)
c0ce7d08 DW	376	ppc_md.kexec_cpu_down(1, 0);
cc532915	377	}