machine_kexec.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * machine_kexec.c - handle transition of Linux booting another kernel
 4 */
 5#include <linux/compiler.h>
 6#include <linux/kexec.h>
 7#include <linux/mm.h>
 8#include <linux/delay.h>
 9#include <linux/reboot.h>
10
11#include <asm/cacheflush.h>
12#include <asm/page.h>
13#include <asm/setup.h>
14
15extern const unsigned char relocate_new_kernel[];
16extern const size_t relocate_new_kernel_size;
17
18int machine_kexec_prepare(struct kimage *kimage)
19{
20	return 0;
21}
22
23void machine_kexec_cleanup(struct kimage *kimage)
24{
25}
26
27void machine_shutdown(void)
28{
29}
30
31void machine_crash_shutdown(struct pt_regs *regs)
32{
33}
34
35typedef void (*relocate_kernel_t)(unsigned long ptr,
36				  unsigned long start,
37				  unsigned long cpu_mmu_flags) __noreturn;
38
39void machine_kexec(struct kimage *image)
40{
41	void *reboot_code_buffer;
42	unsigned long cpu_mmu_flags;
43
44	reboot_code_buffer = page_address(image->control_code_page);
45
46	memcpy(reboot_code_buffer, relocate_new_kernel,
47	       relocate_new_kernel_size);
48
49	/*
50	 * we do not want to be bothered.
51	 */
52	local_irq_disable();
53
54	pr_info("Will call new kernel at 0x%08lx. Bye...\n", image->start);
55	__flush_cache_all();
56	cpu_mmu_flags = m68k_cputype | m68k_mmutype << 8;
57	((relocate_kernel_t) reboot_code_buffer)(image->head & PAGE_MASK,
58						 image->start,
59						 cpu_mmu_flags);
60}