arch/ia64/kernel/crash.c - linux - Git at Google

 /*
  * arch/ia64/kernel/crash.c
  *
  * Architecture specific (ia64) functions for kexec based crash dumps.
  *
  * Created by: Khalid Aziz <khalid.aziz@hp.com>
  * Copyright (C) 2005 Hewlett-Packard Development Company, L.P.
  * Copyright (C) 2005 Intel Corp	Zou Nan hai <nanhai.zou@intel.com>
  *
  */
 #include <linux/smp.h>
 #include <linux/delay.h>
 #include <linux/crash_dump.h>
 #include <linux/bootmem.h>
 #include <linux/kexec.h>
 #include <linux/elfcore.h>
 #include <linux/sysctl.h>
 #include <linux/init.h>
 #include <linux/kdebug.h>

 #include <asm/mca.h>

 int kdump_status[NR_CPUS];
 static atomic_t kdump_cpu_frozen;
 atomic_t kdump_in_progress;
 static int kdump_freeze_monarch;
 static int kdump_on_init = 1;
 static int kdump_on_fatal_mca = 1;

 static inline Elf64_Word
 *append_elf_note(Elf64_Word *buf, char *name, unsigned type, void *data,
 		size_t data_len)
 {
 	struct elf_note *note = (struct elf_note *)buf;
 	note->n_namesz = strlen(name) + 1;
 	note->n_descsz = data_len;
 	note->n_type   = type;
 	buf += (sizeof(*note) + 3)/4;
 	memcpy(buf, name, note->n_namesz);
 	buf += (note->n_namesz + 3)/4;
 	memcpy(buf, data, data_len);
 	buf += (data_len + 3)/4;
 	return buf;
 }

 static void
 final_note(void *buf)
 {
 	memset(buf, 0, sizeof(struct elf_note));
 }

 extern void ia64_dump_cpu_regs(void *);

 static DEFINE_PER_CPU(struct elf_prstatus, elf_prstatus);

 void
 crash_save_this_cpu(void)
 {
 	void *buf;
 	unsigned long cfm, sof, sol;

 	int cpu = smp_processor_id();
 	struct elf_prstatus *prstatus = &per_cpu(elf_prstatus, cpu);

 	elf_greg_t *dst = (elf_greg_t *)&(prstatus->pr_reg);
 	memset(prstatus, 0, sizeof(*prstatus));
 	prstatus->pr_pid = current->pid;

 	ia64_dump_cpu_regs(dst);
 	cfm = dst[43];
 	sol = (cfm >> 7) & 0x7f;
 	sof = cfm & 0x7f;
 	dst[46] = (unsigned long)ia64_rse_skip_regs((unsigned long *)dst[46],
 			sof - sol);

 	buf = (u64 *) per_cpu_ptr(crash_notes, cpu);
 	if (!buf)
 		return;
 	buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, prstatus,
 			sizeof(*prstatus));
 	final_note(buf);
 }

 #ifdef CONFIG_SMP
 static int
 kdump_wait_cpu_freeze(void)
 {
 	int cpu_num = num_online_cpus() - 1;
 	int timeout = 1000;
 	while(timeout-- > 0) {
 		if (atomic_read(&kdump_cpu_frozen) == cpu_num)
 			return 0;
 		udelay(1000);
 	}
 	return 1;
 }
 #endif

 void
 machine_crash_shutdown(struct pt_regs *pt)
 {
 	/* This function is only called after the system
 	 * has paniced 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 shooting down the other cpus in
 	 * an SMP system.
 	 */
 	kexec_disable_iosapic();
 #ifdef CONFIG_SMP
 	/*
 	 * If kdump_on_init is set and an INIT is asserted here, kdump will
 	 * be started again via INIT monarch.
 	 */
 	local_irq_disable();
 	ia64_set_psr_mc();	/* mask MCA/INIT */
 	if (atomic_inc_return(&kdump_in_progress) != 1)
 		unw_init_running(kdump_cpu_freeze, NULL);

 	/*
 	 * Now this cpu is ready for kdump.
 	 * Stop all others by IPI or INIT.  They could receive INIT from
 	 * outside and might be INIT monarch, but only thing they have to
 	 * do is falling into kdump_cpu_freeze().
 	 *
 	 * If an INIT is asserted here:
 	 * - All receivers might be slaves, since some of cpus could already
 	 *   be frozen and INIT might be masked on monarch.  In this case,
 	 *   all slaves will be frozen soon since kdump_in_progress will let
 	 *   them into DIE_INIT_SLAVE_LEAVE.
 	 * - One might be a monarch, but INIT rendezvous will fail since
 	 *   at least this cpu already have INIT masked so it never join
 	 *   to the rendezvous.  In this case, all slaves and monarch will
 	 *   be frozen soon with no wait since the INIT rendezvous is skipped
 	 *   by kdump_in_progress.
 	 */
 	kdump_smp_send_stop();
 	/* not all cpu response to IPI, send INIT to freeze them */
 	if (kdump_wait_cpu_freeze()) {
 		kdump_smp_send_init();
 		/* wait again, don't go ahead if possible */
 		kdump_wait_cpu_freeze();
 	}
 #endif
 }

 static void
 machine_kdump_on_init(void)
 {
 	crash_save_vmcoreinfo();
 	local_irq_disable();
 	kexec_disable_iosapic();
 	machine_kexec(ia64_kimage);
 }

 void
 kdump_cpu_freeze(struct unw_frame_info *info, void *arg)
 {
 	int cpuid;

 	local_irq_disable();
 	cpuid = smp_processor_id();
 	crash_save_this_cpu();
 	current->thread.ksp = (__u64)info->sw - 16;

 	ia64_set_psr_mc();	/* mask MCA/INIT and stop reentrance */

 	atomic_inc(&kdump_cpu_frozen);
 	kdump_status[cpuid] = 1;
 	mb();
 	for (;;)
 		cpu_relax();
 }

 static int
 kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
 {
 	struct ia64_mca_notify_die *nd;
 	struct die_args *args = data;

 	if (atomic_read(&kdump_in_progress)) {
 		switch (val) {
 		case DIE_INIT_MONARCH_LEAVE:
 			if (!kdump_freeze_monarch)
 				break;
 			/* fall through */
 		case DIE_INIT_SLAVE_LEAVE:
 		case DIE_INIT_MONARCH_ENTER:
 		case DIE_MCA_RENDZVOUS_LEAVE:
 			unw_init_running(kdump_cpu_freeze, NULL);
 			break;
 		}
 	}

 	if (!kdump_on_init && !kdump_on_fatal_mca)
 		return NOTIFY_DONE;

 	if (!ia64_kimage) {
 		if (val == DIE_INIT_MONARCH_LEAVE)
 			ia64_mca_printk(KERN_NOTICE
 					"%s: kdump not configured\n",
 					__func__);
 		return NOTIFY_DONE;
 	}

 	if (val != DIE_INIT_MONARCH_LEAVE &&
 	    val != DIE_INIT_MONARCH_PROCESS &&
 	    val != DIE_MCA_MONARCH_LEAVE)
 		return NOTIFY_DONE;

 	nd = (struct ia64_mca_notify_die *)args->err;

 	switch (val) {
 	case DIE_INIT_MONARCH_PROCESS:
 		/* Reason code 1 means machine check rendezvous*/
 		if (kdump_on_init && (nd->sos->rv_rc != 1)) {
 			if (atomic_inc_return(&kdump_in_progress) != 1)
 				kdump_freeze_monarch = 1;
 		}
 		break;
 	case DIE_INIT_MONARCH_LEAVE:
 		/* Reason code 1 means machine check rendezvous*/
 		if (kdump_on_init && (nd->sos->rv_rc != 1))
 			machine_kdump_on_init();
 		break;
 	case DIE_MCA_MONARCH_LEAVE:
 		/* *(nd->data) indicate if MCA is recoverable */
 		if (kdump_on_fatal_mca && !(*(nd->data))) {
 			if (atomic_inc_return(&kdump_in_progress) == 1)
 				machine_kdump_on_init();
 			/* We got fatal MCA while kdump!? No way!! */
 		}
 		break;
 	}
 	return NOTIFY_DONE;
 }

 #ifdef CONFIG_SYSCTL
 static struct ctl_table kdump_ctl_table[] = {
 	{
 		.procname = "kdump_on_init",
 		.data = &kdump_on_init,
 		.maxlen = sizeof(int),
 		.mode = 0644,
 		.proc_handler = proc_dointvec,
 	},
 	{
 		.procname = "kdump_on_fatal_mca",
 		.data = &kdump_on_fatal_mca,
 		.maxlen = sizeof(int),
 		.mode = 0644,
 		.proc_handler = proc_dointvec,
 	},
 	{ }
 };

 static struct ctl_table sys_table[] = {
 	{
 	  .procname = "kernel",
 	  .mode = 0555,
 	  .child = kdump_ctl_table,
 	},
 	{ }
 };
 #endif

 static int
 machine_crash_setup(void)
 {
 	/* be notified before default_monarch_init_process */
 	static struct notifier_block kdump_init_notifier_nb = {
 		.notifier_call = kdump_init_notifier,
 		.priority = 1,
 	};
 	int ret;
 	if((ret = register_die_notifier(&kdump_init_notifier_nb)) != 0)
 		return ret;
 #ifdef CONFIG_SYSCTL
 	register_sysctl_table(sys_table);
 #endif
 	return 0;
 }

 __initcall(machine_crash_setup);
	/*
	* arch/ia64/kernel/crash.c
	*
	* Architecture specific (ia64) functions for kexec based crash dumps.
	*
	* Created by: Khalid Aziz <khalid.aziz@hp.com>
	* Copyright (C) 2005 Hewlett-Packard Development Company, L.P.
	* Copyright (C) 2005 Intel Corp Zou Nan hai <nanhai.zou@intel.com>
	*
	*/
	#include <linux/smp.h>
	#include <linux/delay.h>
	#include <linux/crash_dump.h>
	#include <linux/bootmem.h>
	#include <linux/kexec.h>
	#include <linux/elfcore.h>
	#include <linux/sysctl.h>
	#include <linux/init.h>
	#include <linux/kdebug.h>

	#include <asm/mca.h>

	int kdump_status[NR_CPUS];
	static atomic_t kdump_cpu_frozen;
	atomic_t kdump_in_progress;
	static int kdump_freeze_monarch;
	static int kdump_on_init = 1;
	static int kdump_on_fatal_mca = 1;

	static inline Elf64_Word
	append_elf_note(Elf64_Word buf, char name, unsigned type, void data,
	size_t data_len)
	{
	struct elf_note note = (struct elf_note )buf;
	note->n_namesz = strlen(name) + 1;
	note->n_descsz = data_len;
	note->n_type = type;
	buf += (sizeof(*note) + 3)/4;
	memcpy(buf, name, note->n_namesz);
	buf += (note->n_namesz + 3)/4;
	memcpy(buf, data, data_len);
	buf += (data_len + 3)/4;
	return buf;
	}

	static void
	final_note(void *buf)
	{
	memset(buf, 0, sizeof(struct elf_note));
	}

	extern void ia64_dump_cpu_regs(void *);

	static DEFINE_PER_CPU(struct elf_prstatus, elf_prstatus);

	void
	crash_save_this_cpu(void)
	{
	void *buf;
	unsigned long cfm, sof, sol;

	int cpu = smp_processor_id();
	struct elf_prstatus *prstatus = &per_cpu(elf_prstatus, cpu);

	elf_greg_t dst = (elf_greg_t )&(prstatus->pr_reg);
	memset(prstatus, 0, sizeof(*prstatus));
	prstatus->pr_pid = current->pid;

	ia64_dump_cpu_regs(dst);
	cfm = dst[43];
	sol = (cfm >> 7) & 0x7f;
	sof = cfm & 0x7f;
	dst[46] = (unsigned long)ia64_rse_skip_regs((unsigned long *)dst[46],
	sof - sol);

	buf = (u64 *) per_cpu_ptr(crash_notes, cpu);
	if (!buf)
	return;
	buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, prstatus,
	sizeof(*prstatus));
	final_note(buf);
	}

	#ifdef CONFIG_SMP
	static int
	kdump_wait_cpu_freeze(void)
	{
	int cpu_num = num_online_cpus() - 1;
	int timeout = 1000;
	while(timeout-- > 0) {
	if (atomic_read(&kdump_cpu_frozen) == cpu_num)
	return 0;
	udelay(1000);
	}
	return 1;
	}
	#endif

	void
	machine_crash_shutdown(struct pt_regs *pt)
	{
	/* This function is only called after the system
	* has paniced 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 shooting down the other cpus in
	* an SMP system.
	*/
	kexec_disable_iosapic();
	#ifdef CONFIG_SMP
	/*
	* If kdump_on_init is set and an INIT is asserted here, kdump will
	* be started again via INIT monarch.
	*/
	local_irq_disable();
	ia64_set_psr_mc(); /* mask MCA/INIT */
	if (atomic_inc_return(&kdump_in_progress) != 1)
	unw_init_running(kdump_cpu_freeze, NULL);

	/*
	* Now this cpu is ready for kdump.
	* Stop all others by IPI or INIT. They could receive INIT from
	* outside and might be INIT monarch, but only thing they have to
	* do is falling into kdump_cpu_freeze().
	*
	* If an INIT is asserted here:
	* - All receivers might be slaves, since some of cpus could already
	* be frozen and INIT might be masked on monarch. In this case,
	* all slaves will be frozen soon since kdump_in_progress will let
	* them into DIE_INIT_SLAVE_LEAVE.
	* - One might be a monarch, but INIT rendezvous will fail since
	* at least this cpu already have INIT masked so it never join
	* to the rendezvous. In this case, all slaves and monarch will
	* be frozen soon with no wait since the INIT rendezvous is skipped
	* by kdump_in_progress.
	*/
	kdump_smp_send_stop();
	/* not all cpu response to IPI, send INIT to freeze them */
	if (kdump_wait_cpu_freeze()) {
	kdump_smp_send_init();
	/* wait again, don't go ahead if possible */
	kdump_wait_cpu_freeze();
	}
	#endif
	}

	static void
	machine_kdump_on_init(void)
	{
	crash_save_vmcoreinfo();
	local_irq_disable();
	kexec_disable_iosapic();
	machine_kexec(ia64_kimage);
	}

	void
	kdump_cpu_freeze(struct unw_frame_info info, void arg)
	{
	int cpuid;

	local_irq_disable();
	cpuid = smp_processor_id();
	crash_save_this_cpu();
	current->thread.ksp = (__u64)info->sw - 16;

	ia64_set_psr_mc(); /* mask MCA/INIT and stop reentrance */

	atomic_inc(&kdump_cpu_frozen);
	kdump_status[cpuid] = 1;
	mb();
	for (;;)
	cpu_relax();
	}

	static int
	kdump_init_notifier(struct notifier_block self, unsigned long val, void data)
	{
	struct ia64_mca_notify_die *nd;
	struct die_args *args = data;

	if (atomic_read(&kdump_in_progress)) {
	switch (val) {
	case DIE_INIT_MONARCH_LEAVE:
	if (!kdump_freeze_monarch)
	break;
	/* fall through */
	case DIE_INIT_SLAVE_LEAVE:
	case DIE_INIT_MONARCH_ENTER:
	case DIE_MCA_RENDZVOUS_LEAVE:
	unw_init_running(kdump_cpu_freeze, NULL);
	break;
	}
	}

	if (!kdump_on_init && !kdump_on_fatal_mca)
	return NOTIFY_DONE;

	if (!ia64_kimage) {
	if (val == DIE_INIT_MONARCH_LEAVE)
	ia64_mca_printk(KERN_NOTICE
	"%s: kdump not configured\n",
	__func__);
	return NOTIFY_DONE;
	}

	if (val != DIE_INIT_MONARCH_LEAVE &&
	val != DIE_INIT_MONARCH_PROCESS &&
	val != DIE_MCA_MONARCH_LEAVE)
	return NOTIFY_DONE;

	nd = (struct ia64_mca_notify_die *)args->err;

	switch (val) {
	case DIE_INIT_MONARCH_PROCESS:
	/* Reason code 1 means machine check rendezvous*/
	if (kdump_on_init && (nd->sos->rv_rc != 1)) {
	if (atomic_inc_return(&kdump_in_progress) != 1)
	kdump_freeze_monarch = 1;
	}
	break;
	case DIE_INIT_MONARCH_LEAVE:
	/* Reason code 1 means machine check rendezvous*/
	if (kdump_on_init && (nd->sos->rv_rc != 1))
	machine_kdump_on_init();
	break;
	case DIE_MCA_MONARCH_LEAVE:
	/* (nd->data) indicate if MCA is recoverable /
	if (kdump_on_fatal_mca && !(*(nd->data))) {
	if (atomic_inc_return(&kdump_in_progress) == 1)
	machine_kdump_on_init();
	/* We got fatal MCA while kdump!? No way!! */
	}
	break;
	}
	return NOTIFY_DONE;
	}

	#ifdef CONFIG_SYSCTL
	static struct ctl_table kdump_ctl_table[] = {
	{
	.procname = "kdump_on_init",
	.data = &kdump_on_init,
	.maxlen = sizeof(int),
	.mode = 0644,
	.proc_handler = proc_dointvec,
	},
	{
	.procname = "kdump_on_fatal_mca",
	.data = &kdump_on_fatal_mca,
	.maxlen = sizeof(int),
	.mode = 0644,
	.proc_handler = proc_dointvec,
	},
	{ }
	};

	static struct ctl_table sys_table[] = {
	{
	.procname = "kernel",
	.mode = 0555,
	.child = kdump_ctl_table,
	},
	{ }
	};
	#endif

	static int
	machine_crash_setup(void)
	{
	/* be notified before default_monarch_init_process */
	static struct notifier_block kdump_init_notifier_nb = {
	.notifier_call = kdump_init_notifier,
	.priority = 1,
	};
	int ret;
	if((ret = register_die_notifier(&kdump_init_notifier_nb)) != 0)
	return ret;
	#ifdef CONFIG_SYSCTL
	register_sysctl_table(sys_table);
	#endif
	return 0;
	}

	__initcall(machine_crash_setup);