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linux-next/arch/mips/kernel/machine_kexec.c
Dengcheng Zhu 82689ac663
MIPS: kdump: Mark cpu back online before rebooting
The crash utility initializes cpu state by reading the system kernel
memory, which is copied into vmcore.

It is also natural to preserve the online state for CPUs at crash.

Failing to do so could make the analysis tool present info for only 1 CPU
by default, and unable to find panic task.

Signed-off-by: Dengcheng Zhu <dzhu@wavecomp.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20809/
Cc: Paul Burton <pburton@wavecomp.com>
Cc: "ralf@linux-mips.org" <ralf@linux-mips.org>
Cc: "linux-mips@linux-mips.org" <linux-mips@linux-mips.org>
Cc: "rachel.mozes@intel.com" <rachel.mozes@intel.com>
2018-09-28 10:09:03 -07:00

267 lines
6.0 KiB
C

/*
* machine_kexec.c for kexec
* Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/compiler.h>
#include <linux/kexec.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/libfdt.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
extern const unsigned char relocate_new_kernel[];
extern const size_t relocate_new_kernel_size;
extern unsigned long kexec_start_address;
extern unsigned long kexec_indirection_page;
static unsigned long reboot_code_buffer;
#ifdef CONFIG_SMP
static void (*relocated_kexec_smp_wait)(void *);
atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
void (*_crash_smp_send_stop)(void) = NULL;
#endif
void (*_machine_kexec_shutdown)(void) = NULL;
void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
static void kexec_image_info(const struct kimage *kimage)
{
unsigned long i;
pr_debug("kexec kimage info:\n");
pr_debug(" type: %d\n", kimage->type);
pr_debug(" start: %lx\n", kimage->start);
pr_debug(" head: %lx\n", kimage->head);
pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
for (i = 0; i < kimage->nr_segments; i++) {
pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
i,
kimage->segment[i].mem,
kimage->segment[i].mem + kimage->segment[i].memsz,
(unsigned long)kimage->segment[i].memsz,
(unsigned long)kimage->segment[i].memsz / PAGE_SIZE);
}
}
#ifdef CONFIG_UHI_BOOT
static int uhi_machine_kexec_prepare(struct kimage *kimage)
{
int i;
/*
* In case DTB file is not passed to the new kernel, a flat device
* tree will be created by kexec tool. It holds modified command
* line for the new kernel.
*/
for (i = 0; i < kimage->nr_segments; i++) {
struct fdt_header fdt;
if (kimage->segment[i].memsz <= sizeof(fdt))
continue;
if (copy_from_user(&fdt, kimage->segment[i].buf, sizeof(fdt)))
continue;
if (fdt_check_header(&fdt))
continue;
kexec_args[0] = -2;
kexec_args[1] = (unsigned long)
phys_to_virt((unsigned long)kimage->segment[i].mem);
break;
}
return 0;
}
int (*_machine_kexec_prepare)(struct kimage *) = uhi_machine_kexec_prepare;
#else
int (*_machine_kexec_prepare)(struct kimage *) = NULL;
#endif /* CONFIG_UHI_BOOT */
int
machine_kexec_prepare(struct kimage *kimage)
{
#ifdef CONFIG_SMP
if (!kexec_nonboot_cpu_func())
return -EINVAL;
#endif
kexec_image_info(kimage);
if (_machine_kexec_prepare)
return _machine_kexec_prepare(kimage);
return 0;
}
void
machine_kexec_cleanup(struct kimage *kimage)
{
}
#ifdef CONFIG_SMP
static void kexec_shutdown_secondary(void *param)
{
int cpu = smp_processor_id();
if (!cpu_online(cpu))
return;
/* We won't be sent IPIs any more. */
set_cpu_online(cpu, false);
local_irq_disable();
while (!atomic_read(&kexec_ready_to_reboot))
cpu_relax();
kexec_reboot();
/* NOTREACHED */
}
#endif
void
machine_shutdown(void)
{
if (_machine_kexec_shutdown)
_machine_kexec_shutdown();
#ifdef CONFIG_SMP
smp_call_function(kexec_shutdown_secondary, NULL, 0);
while (num_online_cpus() > 1) {
cpu_relax();
mdelay(1);
}
#endif
}
void
machine_crash_shutdown(struct pt_regs *regs)
{
if (_machine_crash_shutdown)
_machine_crash_shutdown(regs);
else
default_machine_crash_shutdown(regs);
}
#ifdef CONFIG_SMP
void kexec_nonboot_cpu_jump(void)
{
local_flush_icache_range((unsigned long)relocated_kexec_smp_wait,
reboot_code_buffer + relocate_new_kernel_size);
relocated_kexec_smp_wait(NULL);
}
#endif
void kexec_reboot(void)
{
void (*do_kexec)(void) __noreturn;
/*
* We know we were online, and there will be no incoming IPIs at
* this point. Mark online again before rebooting so that the crash
* analysis tool will see us correctly.
*/
set_cpu_online(smp_processor_id(), true);
/* Ensure remote CPUs observe that we're online before rebooting. */
smp_mb__after_atomic();
#ifdef CONFIG_SMP
if (smp_processor_id() > 0) {
/*
* Instead of cpu_relax() or wait, this is needed for kexec
* smp reboot. Kdump usually doesn't require an smp new
* kernel, but kexec may do.
*/
kexec_nonboot_cpu();
/* NOTREACHED */
}
#endif
/*
* Make sure we get correct instructions written by the
* machine_kexec() CPU.
*/
local_flush_icache_range(reboot_code_buffer,
reboot_code_buffer + relocate_new_kernel_size);
do_kexec = (void *)reboot_code_buffer;
do_kexec();
}
void
machine_kexec(struct kimage *image)
{
unsigned long entry;
unsigned long *ptr;
reboot_code_buffer =
(unsigned long)page_address(image->control_code_page);
kexec_start_address =
(unsigned long) phys_to_virt(image->start);
if (image->type == KEXEC_TYPE_DEFAULT) {
kexec_indirection_page =
(unsigned long) phys_to_virt(image->head & PAGE_MASK);
} else {
kexec_indirection_page = (unsigned long)&image->head;
}
memcpy((void*)reboot_code_buffer, relocate_new_kernel,
relocate_new_kernel_size);
/*
* The generic kexec code builds a page list with physical
* addresses. they are directly accessible through KSEG0 (or
* CKSEG0 or XPHYS if on 64bit system), hence the
* phys_to_virt() call.
*/
for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
ptr = (entry & IND_INDIRECTION) ?
phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
*ptr & IND_DESTINATION)
*ptr = (unsigned long) phys_to_virt(*ptr);
}
/* Mark offline BEFORE disabling local irq. */
set_cpu_online(smp_processor_id(), false);
/*
* we do not want to be bothered.
*/
local_irq_disable();
printk("Will call new kernel at %08lx\n", image->start);
printk("Bye ...\n");
/* Make reboot code buffer available to the boot CPU. */
__flush_cache_all();
#ifdef CONFIG_SMP
/* All secondary cpus now may jump to kexec_wait cycle */
relocated_kexec_smp_wait = reboot_code_buffer +
(void *)(kexec_smp_wait - relocate_new_kernel);
smp_wmb();
atomic_set(&kexec_ready_to_reboot, 1);
#endif
kexec_reboot();
}