Quellcode-Bibliothek kexec.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0

#include <linux/kernel.h>
#include <linux/console.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/reboot.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;
}