xref: /openbmc/linux/arch/arm/kernel/machine_kexec.c (revision f42b3800)
1 /*
2  * machine_kexec.c - handle transition of Linux booting another kernel
3  */
4 
5 #include <linux/mm.h>
6 #include <linux/kexec.h>
7 #include <linux/delay.h>
8 #include <linux/reboot.h>
9 #include <asm/pgtable.h>
10 #include <asm/pgalloc.h>
11 #include <asm/mmu_context.h>
12 #include <asm/io.h>
13 #include <asm/cacheflush.h>
14 #include <asm/mach-types.h>
15 
16 const extern unsigned char relocate_new_kernel[];
17 const extern unsigned int relocate_new_kernel_size;
18 
19 extern void setup_mm_for_reboot(char mode);
20 
21 extern unsigned long kexec_start_address;
22 extern unsigned long kexec_indirection_page;
23 extern unsigned long kexec_mach_type;
24 extern unsigned long kexec_boot_atags;
25 
26 /*
27  * Provide a dummy crash_notes definition while crash dump arrives to arm.
28  * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
29  */
30 
31 int machine_kexec_prepare(struct kimage *image)
32 {
33 	return 0;
34 }
35 
36 void machine_kexec_cleanup(struct kimage *image)
37 {
38 }
39 
40 void machine_shutdown(void)
41 {
42 }
43 
44 void machine_crash_shutdown(struct pt_regs *regs)
45 {
46 }
47 
48 void machine_kexec(struct kimage *image)
49 {
50 	unsigned long page_list;
51 	unsigned long reboot_code_buffer_phys;
52 	void *reboot_code_buffer;
53 
54 
55 	page_list = image->head & PAGE_MASK;
56 
57 	/* we need both effective and real address here */
58 	reboot_code_buffer_phys =
59 	    page_to_pfn(image->control_code_page) << PAGE_SHIFT;
60 	reboot_code_buffer = page_address(image->control_code_page);
61 
62 	/* Prepare parameters for reboot_code_buffer*/
63 	kexec_start_address = image->start;
64 	kexec_indirection_page = page_list;
65 	kexec_mach_type = machine_arch_type;
66 	kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
67 
68 	/* copy our kernel relocation code to the control code page */
69 	memcpy(reboot_code_buffer,
70 	       relocate_new_kernel, relocate_new_kernel_size);
71 
72 
73 	flush_icache_range((unsigned long) reboot_code_buffer,
74 			   (unsigned long) reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
75 	printk(KERN_INFO "Bye!\n");
76 
77 	cpu_proc_fin();
78 	setup_mm_for_reboot(0); /* mode is not used, so just pass 0*/
79 	cpu_reset(reboot_code_buffer_phys);
80 }
81