Merge branch 'kexec' into next

#define KEXEC_STATE_REAL_MODE 2

#ifndef __ASSEMBLY__

#include <linux/cpumask.h>

#include <asm/reg.h>

typedef void (*crash_shutdown_t)(void);

					  master to copy new code to 0 */

extern int crashing_cpu;

extern void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *));

extern cpumask_t cpus_in_sr;

static inline int kexec_sr_activated(int cpu)

{

	return cpumask_test_cpu(cpu, &cpus_in_sr);

}

struct kimage;

struct pt_regs;

extern void machine_kexec_mask_interrupts(void);

#else /* !CONFIG_KEXEC */

static inline int kexec_sr_activated(int cpu) { return 0; }

static inline void crash_kexec_secondary(struct pt_regs *regs) { }

static inline int overlaps_crashkernel(unsigned long start, unsigned long size)

extern void *cacheable_memcpy(void *, const void *, unsigned int);

extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);

extern void bad_page_fault(struct pt_regs *, unsigned long, int);

extern int die(const char *, struct pt_regs *, long);

extern void _exception(int, struct pt_regs *, int, unsigned long);

extern void die(const char *, struct pt_regs *, long);

extern void _nmask_and_or_msr(unsigned long nmask, unsigned long or_val);

#ifdef CONFIG_BOOKE_WDT

 *

 */

#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

/*

 * 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

/* This keeps a track of which one is crashing cpu. */

#define IPI_TIMEOUT		10000

#define REAL_MODE_TIMEOUT	10000

/* This keeps a track of which one is the crashing cpu. */

int crashing_cpu = -1;

static cpumask_t cpus_in_crash = CPU_MASK_NONE;

cpumask_t cpus_in_sr = CPU_MASK_NONE;

static atomic_t cpus_in_crash;

static int time_to_dump;

#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);

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 enter_on_soft_reset = ATOMIC_INIT(0);

void crash_ipi_callback(struct pt_regs *regs)

{

	static cpumask_t cpus_state_saved = CPU_MASK_NONE;

	int cpu = smp_processor_id();

	if (!cpu_online(cpu))

		return;

	hard_irq_disable();

	if (!cpumask_test_cpu(cpu, &cpus_in_crash))

	if (!cpumask_test_cpu(cpu, &cpus_state_saved)) {

		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);

		cpumask_set_cpu(cpu, &cpus_state_saved);

	}

	atomic_inc(&cpus_in_crash);

	smp_mb__after_atomic_inc();

	/*

	 * 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))

	while (!time_to_dump)

		cpu_relax();

	if (ppc_md.kexec_cpu_down)

	/* 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 */

	int tries = 0;

	int (*old_handler)(struct pt_regs *regs);

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

	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.

	 * 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();

	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));

	/*

	 * 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 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 (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();

	}

	if ((panic_timeout > 0) || (tries > 0))

		return;

	/*

	 * Make sure all CPUs are entered via soft-reset if the kdump is

	 * invoked using soft-reset.

	 * 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.

	 */

	if (cpumask_test_cpu(cpu, &cpus_in_sr))

		crash_soft_reset_check(cpu);

	/* Leave the IPI callback set */

	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 or by kexec cpu

 * if soft-reset is activated to stop some CPUs.

 * This function will be called by secondary cpus.

 */

void crash_kexec_secondary(struct pt_regs *regs)

{

	int cpu = smp_processor_id();

	unsigned long flags;

	int msecs = 5;

	int msecs = SECONDARY_TIMEOUT;

	local_irq_save(flags);

	/* Wait 5ms if the kexec CPU is not entered yet. */

	/* Wait for the primary crash CPU to signal its progress */

	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);

			/* No response, kdump image may not have been loaded */

			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);

}

static void crash_kexec_prepare_cpus(int cpu)

{

	/*

	 * move the secondarys to us so that we can copy

	 * move the secondaries to us so that we can copy

	 * the new kernel 0-0x100 safely

	 *

	 * do this if kexec in setup.c ?

void crash_kexec_secondary(struct pt_regs *regs)

{

	cpumask_clear(&cpus_in_sr);

}

#endif	/* CONFIG_SMP */

	unsigned int msecs;

	int i;

	msecs = 10000;

	msecs = REAL_MODE_TIMEOUT;

	for (i=0; i < nr_cpu_ids && msecs > 0; i++) {

		if (i == cpu)

			continue;

}

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.

	 * such that another IPI will not be sent.

	 */

	crashing_cpu = smp_processor_id();

	crash_save_cpu(regs, crashing_cpu);

	/*

	 * 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);

	cpumask_set_cpu(crashing_cpu, &cpus_in_crash);

	crash_save_cpu(regs, crashing_cpu);

	time_to_dump = 1;

	crash_kexec_wait_realmode(crashing_cpu);

	machine_kexec_mask_interrupts();

	/*

	 * Call registered shutdown routines savely.  Swap out

	 * Call registered shutdown routines safely.  Swap out

	 * __debugger_fault_handler, and replace on exit.

	 */

	old_handler = __debugger_fault_handler;

static inline void pmac_backlight_unblank(void) { }

#endif

int die(const char *str, struct pt_regs *regs, long err)

{

	static struct {

		raw_spinlock_t lock;

		u32 lock_owner;

		int lock_owner_depth;

	} die = {

		.lock =			__RAW_SPIN_LOCK_UNLOCKED(die.lock),

		.lock_owner =		-1,

		.lock_owner_depth =	0

	};

static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;

static int die_owner = -1;

static unsigned int die_nest_count;

static int die_counter;

static unsigned __kprobes long oops_begin(struct pt_regs *regs)

{

	int cpu;

	unsigned long flags;

	if (debugger(regs))

	oops_enter();

	if (die.lock_owner != raw_smp_processor_id()) {

	/* racy, but better than risking deadlock. */

	raw_local_irq_save(flags);

	cpu = smp_processor_id();

	if (!arch_spin_trylock(&die_lock)) {

		if (cpu == die_owner)

			/* nested oops. should stop eventually */;

		else

			arch_spin_lock(&die_lock);

	}

	die_nest_count++;

	die_owner = cpu;

	console_verbose();

		raw_spin_lock_irqsave(&die.lock, flags);

		die.lock_owner = smp_processor_id();

		die.lock_owner_depth = 0;

	bust_spinlocks(1);

	if (machine_is(powermac))

		pmac_backlight_unblank();

	} else {

		local_save_flags(flags);

	return flags;

}

static void __kprobes oops_end(unsigned long flags, struct pt_regs *regs,

			       int signr)

{

	bust_spinlocks(0);

	die_owner = -1;

	add_taint(TAINT_DIE);

	die_nest_count--;

	oops_exit();

	printk("\n");

	if (!die_nest_count)

		/* Nest count reaches zero, release the lock. */

		arch_spin_unlock(&die_lock);

	raw_local_irq_restore(flags);

	/*

	 * A system reset (0x100) is a request to dump, so we always send

	 * it through the crashdump code.

	 */

	if (kexec_should_crash(current) || (TRAP(regs) == 0x100)) {

		crash_kexec(regs);

		/*

		 * We aren't the primary crash CPU. We need to send it

		 * to a holding pattern to avoid it ending up in the panic

		 * code.

		 */

		crash_kexec_secondary(regs);

	}

	if (!signr)

		return;

	/*

	 * While our oops output is serialised by a spinlock, output

	 * from panic() called below can race and corrupt it. If we

	 * know we are going to panic, delay for 1 second so we have a

	 * chance to get clean backtraces from all CPUs that are oopsing.

	 */

	if (in_interrupt() || panic_on_oops || !current->pid ||

	    is_global_init(current)) {

		mdelay(MSEC_PER_SEC);

	}

	if (in_interrupt())

		panic("Fatal exception in interrupt");

	if (panic_on_oops)

		panic("Fatal exception");

	do_exit(signr);

}

	if (++die.lock_owner_depth < 3) {

static int __kprobes __die(const char *str, struct pt_regs *regs, long err)

{

	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);

#ifdef CONFIG_PREEMPT

	printk("PREEMPT ");

#endif

	printk("%s\n", ppc_md.name ? ppc_md.name : "");

		if (notify_die(DIE_OOPS, str, regs, err, 255,

			       SIGSEGV) == NOTIFY_STOP)

	if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP)

		return 1;

	print_modules();

	show_regs(regs);

	} else {

		printk("Recursive die() failure, output suppressed\n");

	}

	bust_spinlocks(0);

	die.lock_owner = -1;

	add_taint(TAINT_DIE);

	raw_spin_unlock_irqrestore(&die.lock, flags);

	if (kexec_should_crash(current) ||

		kexec_sr_activated(smp_processor_id()))

		crash_kexec(regs);

	crash_kexec_secondary(regs);

	if (in_interrupt())

		panic("Fatal exception in interrupt");

	if (panic_on_oops)

		panic("Fatal exception");

	return 0;

}

	oops_exit();

	do_exit(err);

void die(const char *str, struct pt_regs *regs, long err)

{

	unsigned long flags = oops_begin(regs);

	return 0;

	if (__die(str, regs, err))

		err = 0;

	oops_end(flags, regs, err);

}

void user_single_step_siginfo(struct task_struct *tsk,

			"at %016lx nip %016lx lr %016lx code %x\n";

	if (!user_mode(regs)) {

		if (die("Exception in kernel mode", regs, signr))

		die("Exception in kernel mode", regs, signr);

		return;

	} else if (show_unhandled_signals &&

		   unhandled_signal(current, signr)) {

	}

	if (show_unhandled_signals && unhandled_signal(current, signr)) {

		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,

				   current->comm, current->pid, signr,

				   addr, regs->nip, regs->link, code);

			return;

	}

#ifdef CONFIG_KEXEC

	cpumask_set_cpu(smp_processor_id(), &cpus_in_sr);

#endif

	die("System Reset", regs, SIGABRT);

	/*

	 * Some CPUs when released from the debugger will execute this path.

	 * These CPUs entered the debugger via a soft-reset. If the CPU was

	 * hung before entering the debugger it will return to the hung

	 * state when exiting this function.  This causes a problem in

	 * kdump since the hung CPU(s) will not respond to the IPI sent

	 * from kdump. To prevent the problem we call crash_kexec_secondary()

	 * here. If a kdump had not been initiated or we exit the debugger

	 * with the "exit and recover" command (x) crash_kexec_secondary()

	 * will return after 5ms and the CPU returns to its previous state.

	 */

	crash_kexec_secondary(regs);

	/* Must die if the interrupt is not recoverable */

	if (!(regs->msr & MSR_RI))

		panic("Unrecoverable System Reset");

static void __init pSeries_setup_arch(void)

{

	panic_timeout = 10;

	/* Discover PIC type and setup ppc_md accordingly */

	pseries_discover_pic();