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// SPDX-License-Identifier: GPL-2.0
/*
* machine_kexec.c - handle transition of Linux booting another kernel
*/
#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
#include <asm/kexec-internal.h>
#include <asm/fncpy.h>
#include <asm/mach-types.h>
#include <asm/smp_plat.h>
#include <asm/system_misc.h>
#include <asm/set_memory.h>
extern void relocate_new_kernel(void);
extern const unsigned int relocate_new_kernel_size;
static atomic_t waiting_for_crash_ipi;
/*
* Provide a dummy crash_notes definition while crash dump arrives to arm.
* This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
*/
int machine_kexec_prepare(struct kimage *image)
{
struct kexec_segment *current_segment;
__be32 header;
int i, err;
image->arch.kernel_r2 = image->start - KEXEC_ARM_ZIMAGE_OFFSET
+ KEXEC_ARM_ATAGS_OFFSET;
/*
* Validate that if the current HW supports SMP, then the SW supports
* and implements CPU hotplug for the current HW. If not, we won't be
* able to kexec reliably, so fail the prepare operation.
*/
if (num_possible_cpus() > 1 && platform_can_secondary_boot() &&
!platform_can_cpu_hotplug())
return -EINVAL;
/*
* No segment at default ATAGs address. try to locate
* a dtb using magic.
*/
for (i = 0; i < image->nr_segments; i++) {
current_segment = &image->segment[i];
if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem),
current_segment->memsz))
return -EINVAL;
err = get_user(header, (__be32*)current_segment->buf);
if (err)
return err;
if (header == cpu_to_be32(OF_DT_HEADER))
image->arch.kernel_r2 = current_segment->mem;
}
return 0;
}
void machine_kexec_cleanup(struct kimage *image)
{
}
static void machine_crash_nonpanic_core(void *unused)
{
struct pt_regs regs;
crash_setup_regs(®s, get_irq_regs());
printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
smp_processor_id());
crash_save_cpu(®s, smp_processor_id());
flush_cache_all();
set_cpu_online(smp_processor_id(), false);
atomic_dec(&waiting_for_crash_ipi);
while (1) {
cpu_relax();
wfe();
}
}
void crash_smp_send_stop(void)
{
static int cpus_stopped;
unsigned long msecs;
if (cpus_stopped)
return;
atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
smp_call_function(machine_crash_nonpanic_core, NULL, false);
msecs = 1000; /* Wait at most a second for the other cpus to stop */
while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
mdelay(1);
msecs--;
}
if (atomic_read(&waiting_for_crash_ipi) > 0)
pr_warn("Non-crashing CPUs did not react to IPI\n");
cpus_stopped = 1;
}
static void machine_kexec_mask_interrupts(void)
{
unsigned int i;
struct irq_desc *desc;
for_each_irq_desc(i, desc) {
struct irq_chip *chip;
chip = irq_desc_get_chip(desc);
if (!chip)
continue;
if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
chip->irq_eoi(&desc->irq_data);
if (chip->irq_mask)
chip->irq_mask(&desc->irq_data);
if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
chip->irq_disable(&desc->irq_data);
}
}
void machine_crash_shutdown(struct pt_regs *regs)
{
local_irq_disable();
crash_smp_send_stop();
crash_save_cpu(regs, smp_processor_id());
machine_kexec_mask_interrupts();
pr_info("Loading crashdump kernel...\n");
}
void machine_kexec(struct kimage *image)
{
unsigned long page_list, reboot_entry_phys;
struct kexec_relocate_data *data;
void (*reboot_entry)(void);
void *reboot_code_buffer;
/*
* This can only happen if machine_shutdown() failed to disable some
* CPU, and that can only happen if the checks in
* machine_kexec_prepare() were not correct. If this fails, we can't
* reliably kexec anyway, so BUG_ON is appropriate.
*/
BUG_ON(num_online_cpus() > 1);
page_list = image->head & PAGE_MASK;
reboot_code_buffer = page_address(image->control_code_page);
/* copy our kernel relocation code to the control code page */
reboot_entry = fncpy(reboot_code_buffer,
&relocate_new_kernel,
relocate_new_kernel_size);
data = reboot_code_buffer + relocate_new_kernel_size;
data->kexec_start_address = image->start;
data->kexec_indirection_page = page_list;
data->kexec_mach_type = machine_arch_type;
data->kexec_r2 = image->arch.kernel_r2;
/* get the identity mapping physical address for the reboot code */
reboot_entry_phys = virt_to_idmap(reboot_entry);
pr_info("Bye!\n");
soft_restart(reboot_entry_phys);
}
void arch_crash_save_vmcoreinfo(void)
{
#ifdef CONFIG_ARM_LPAE
VMCOREINFO_CONFIG(ARM_LPAE);
#endif
}
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