// SPDX-License-Identifier: GPL-2.0
/*
* 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/memblock.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;
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);
