kexec.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/console.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
extern void relocate_new_kernel(unsigned long head,
unsigned long start,
unsigned long phys);
extern const unsigned int relocate_new_kernel_size;
extern unsigned int kexec_initrd_start_offset;
extern unsigned int kexec_initrd_end_offset;
extern unsigned int kexec_cmdline_offset;
extern unsigned int kexec_free_mem_offset;
static void kexec_show_segment_info(const struct kimage *kimage,
unsigned long n)
{
pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
n,
kimage->segment[n].mem,
kimage->segment[n].mem + kimage->segment[n].memsz,
(unsigned long)kimage->segment[n].memsz,
(unsigned long)kimage->segment[n].memsz / PAGE_SIZE);
}
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++)
kexec_show_segment_info(kimage, i);
#ifdef CONFIG_KEXEC_FILE
if (kimage->file_mode) {
pr_debug("cmdline: %.*s\n", (int)kimage->cmdline_buf_len,
kimage->cmdline_buf);
}
#endif
}
void machine_kexec_cleanup(struct kimage *kimage)
{
}
void machine_crash_shutdown(struct pt_regs *regs)
{
}
void machine_shutdown(void)
{
smp_send_stop();
while (num_online_cpus() > 1) {
cpu_relax();
mdelay(1);
}
}
void machine_kexec(struct kimage *image)
{
#ifdef CONFIG_64BIT
Elf64_Fdesc desc;
#endif
void (*reloc)(unsigned long head,
unsigned long start,
unsigned long phys);
unsigned long phys = page_to_phys(image->control_code_page);
void *virt = (void *)__fix_to_virt(FIX_TEXT_KEXEC);
struct kimage_arch *arch = &image->arch;
set_fixmap(FIX_TEXT_KEXEC, phys);
flush_cache_all();
#ifdef CONFIG_64BIT
reloc = (void *)&desc;
desc.addr = (long long)virt;
#else
reloc = (void *)virt;
#endif
memcpy(virt, dereference_function_descriptor(relocate_new_kernel),
relocate_new_kernel_size);
*(unsigned long *)(virt + kexec_cmdline_offset) = arch->cmdline;
*(unsigned long *)(virt + kexec_initrd_start_offset) = arch->initrd_start;
*(unsigned long *)(virt + kexec_initrd_end_offset) = arch->initrd_end;
*(unsigned long *)(virt + kexec_free_mem_offset) = PAGE0->mem_free;
flush_cache_all();
flush_tlb_all();
local_irq_disable();
reloc(image->head & PAGE_MASK, image->start, phys);
}
int machine_kexec_prepare(struct kimage *image)
{
kexec_image_info(image);
return 0;
}