xref: /openbmc/linux/arch/s390/kernel/machine_kexec.c (revision 565d76cb)
1 /*
2  * arch/s390/kernel/machine_kexec.c
3  *
4  * Copyright IBM Corp. 2005,2006
5  *
6  * Author(s): Rolf Adelsberger,
7  *	      Heiko Carstens <heiko.carstens@de.ibm.com>
8  */
9 
10 #include <linux/device.h>
11 #include <linux/mm.h>
12 #include <linux/kexec.h>
13 #include <linux/delay.h>
14 #include <linux/reboot.h>
15 #include <linux/ftrace.h>
16 #include <asm/cio.h>
17 #include <asm/setup.h>
18 #include <asm/pgtable.h>
19 #include <asm/pgalloc.h>
20 #include <asm/system.h>
21 #include <asm/smp.h>
22 #include <asm/reset.h>
23 #include <asm/ipl.h>
24 
25 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
26 
27 extern const unsigned char relocate_kernel[];
28 extern const unsigned long long relocate_kernel_len;
29 
30 int machine_kexec_prepare(struct kimage *image)
31 {
32 	void *reboot_code_buffer;
33 
34 	/* Can't replace kernel image since it is read-only. */
35 	if (ipl_flags & IPL_NSS_VALID)
36 		return -ENOSYS;
37 
38 	/* We don't support anything but the default image type for now. */
39 	if (image->type != KEXEC_TYPE_DEFAULT)
40 		return -EINVAL;
41 
42 	/* Get the destination where the assembler code should be copied to.*/
43 	reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
44 
45 	/* Then copy it */
46 	memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
47 	return 0;
48 }
49 
50 void machine_kexec_cleanup(struct kimage *image)
51 {
52 }
53 
54 void machine_shutdown(void)
55 {
56 }
57 
58 static void __machine_kexec(void *data)
59 {
60 	relocate_kernel_t data_mover;
61 	struct kimage *image = data;
62 
63 	pfault_fini();
64 	s390_reset_system();
65 
66 	data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
67 
68 	/* Call the moving routine */
69 	(*data_mover)(&image->head, image->start);
70 	for (;;);
71 }
72 
73 void machine_kexec(struct kimage *image)
74 {
75 	tracer_disable();
76 	smp_send_stop();
77 	smp_switch_to_ipl_cpu(__machine_kexec, image);
78 }
79