machine_kexec.c revision 54622f10a6aabb8bb2bdacf3dd070046f03dc246 
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 <linux/lmb.h>
16#include <asm/machdep.h>
17#include <asm/prom.h>
18
19void machine_crash_shutdown(struct pt_regs *regs)
20{
21	if (ppc_md.machine_crash_shutdown)
22		ppc_md.machine_crash_shutdown(regs);
23}
24
25/*
26 * Do what every setup is needed on image and the
27 * reboot code buffer to allow us to avoid allocations
28 * later.
29 */
30int machine_kexec_prepare(struct kimage *image)
31{
32	if (ppc_md.machine_kexec_prepare)
33		return ppc_md.machine_kexec_prepare(image);
34	/*
35	 * Fail if platform doesn't provide its own machine_kexec_prepare
36	 * implementation.
37	 */
38	return -ENOSYS;
39}
40
41void machine_kexec_cleanup(struct kimage *image)
42{
43	if (ppc_md.machine_kexec_cleanup)
44		ppc_md.machine_kexec_cleanup(image);
45}
46
47/*
48 * Do not allocate memory (or fail in any way) in machine_kexec().
49 * We are past the point of no return, committed to rebooting now.
50 */
51void machine_kexec(struct kimage *image)
52{
53	if (ppc_md.machine_kexec)
54		ppc_md.machine_kexec(image);
55	else {
56		/*
57		 * Fall back to normal restart if platform doesn't provide
58		 * its own kexec function, and user insist to kexec...
59		 */
60		machine_restart(NULL);
61	}
62	for(;;);
63}
64
65void __init reserve_crashkernel(void)
66{
67	unsigned long long crash_size, crash_base;
68	int ret;
69
70	/* this is necessary because of lmb_phys_mem_size() */
71	lmb_analyze();
72
73	/* use common parsing */
74	ret = parse_crashkernel(boot_command_line, lmb_phys_mem_size(),
75			&crash_size, &crash_base);
76	if (ret == 0 && crash_size > 0) {
77		crashk_res.start = crash_base;
78		crashk_res.end = crash_base + crash_size - 1;
79	}
80
81	if (crashk_res.end == crashk_res.start) {
82		crashk_res.start = crashk_res.end = 0;
83		return;
84	}
85
86	/* We might have got these values via the command line or the
87	 * device tree, either way sanitise them now. */
88
89	crash_size = crashk_res.end - crashk_res.start + 1;
90
91#ifndef CONFIG_RELOCATABLE
92	if (crashk_res.start != KDUMP_KERNELBASE)
93		printk("Crash kernel location must be 0x%x\n",
94				KDUMP_KERNELBASE);
95
96	crashk_res.start = KDUMP_KERNELBASE;
97#endif
98	crash_size = PAGE_ALIGN(crash_size);
99	crashk_res.end = crashk_res.start + crash_size - 1;
100
101	/* Crash kernel trumps memory limit */
102	if (memory_limit && memory_limit <= crashk_res.end) {
103		memory_limit = crashk_res.end + 1;
104		printk("Adjusted memory limit for crashkernel, now 0x%lx\n",
105				memory_limit);
106	}
107
108	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
109			"for crashkernel (System RAM: %ldMB)\n",
110			(unsigned long)(crash_size >> 20),
111			(unsigned long)(crashk_res.start >> 20),
112			(unsigned long)(lmb_phys_mem_size() >> 20));
113
114	lmb_reserve(crashk_res.start, crash_size);
115}
116
117int overlaps_crashkernel(unsigned long start, unsigned long size)
118{
119	return (start + size) > crashk_res.start && start <= crashk_res.end;
120}
121