machine_kexec.c revision 47585d8f5dea10dea49c948f1fb13ef7632409c7 
1/*
2 * Code to handle transition of Linux booting another kernel.
3 *
4 * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
5 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
6 * Copyright (C) 2005 IBM Corporation.
7 *
8 * This source code is licensed under the GNU General Public License,
9 * Version 2.  See the file COPYING for more details.
10 */
11
12#include <linux/kexec.h>
13#include <linux/reboot.h>
14#include <linux/threads.h>
15#include <asm/machdep.h>
16#include <asm/lmb.h>
17
18void machine_crash_shutdown(struct pt_regs *regs)
19{
20	if (ppc_md.machine_crash_shutdown)
21		ppc_md.machine_crash_shutdown(regs);
22}
23
24/*
25 * Do what every setup is needed on image and the
26 * reboot code buffer to allow us to avoid allocations
27 * later.
28 */
29int machine_kexec_prepare(struct kimage *image)
30{
31	if (ppc_md.machine_kexec_prepare)
32		return ppc_md.machine_kexec_prepare(image);
33	/*
34	 * Fail if platform doesn't provide its own machine_kexec_prepare
35	 * implementation.
36	 */
37	return -ENOSYS;
38}
39
40void machine_kexec_cleanup(struct kimage *image)
41{
42	if (ppc_md.machine_kexec_cleanup)
43		ppc_md.machine_kexec_cleanup(image);
44}
45
46/*
47 * Do not allocate memory (or fail in any way) in machine_kexec().
48 * We are past the point of no return, committed to rebooting now.
49 */
50NORET_TYPE void machine_kexec(struct kimage *image)
51{
52	if (ppc_md.machine_kexec)
53		ppc_md.machine_kexec(image);
54	else {
55		/*
56		 * Fall back to normal restart if platform doesn't provide
57		 * its own kexec function, and user insist to kexec...
58		 */
59		machine_restart(NULL);
60	}
61	for(;;);
62}
63
64static int __init early_parse_crashk(char *p)
65{
66	unsigned long size;
67
68	if (!p)
69		return 1;
70
71	size = memparse(p, &p);
72
73	if (*p == '@')
74		crashk_res.start = memparse(p + 1, &p);
75	else
76		crashk_res.start = KDUMP_KERNELBASE;
77
78	crashk_res.end = crashk_res.start + size - 1;
79
80	return 0;
81}
82early_param("crashkernel", early_parse_crashk);
83
84void __init reserve_crashkernel(void)
85{
86	unsigned long size;
87
88	if (crashk_res.start == 0)
89		return;
90
91	/* We might have got these values via the command line or the
92	 * device tree, either way sanitise them now. */
93
94	size = crashk_res.end - crashk_res.start + 1;
95
96	if (crashk_res.start != KDUMP_KERNELBASE)
97		printk("Crash kernel location must be 0x%x\n",
98				KDUMP_KERNELBASE);
99
100	crashk_res.start = KDUMP_KERNELBASE;
101	size = PAGE_ALIGN(size);
102	crashk_res.end = crashk_res.start + size - 1;
103
104	/* Crash kernel trumps memory limit */
105	if (memory_limit && memory_limit <= crashk_res.end) {
106		memory_limit = crashk_res.end + 1;
107		printk("Adjusted memory limit for crashkernel, now 0x%lx\n",
108				memory_limit);
109	}
110
111	lmb_reserve(crashk_res.start, size);
112}
113
114int overlaps_crashkernel(unsigned long start, unsigned long size)
115{
116	return (start + size) > crashk_res.start && start <= crashk_res.end;
117}
118