machine_kexec.c revision 67238fb721639046b5d76488317522af4ece9d61 
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 <linux/of.h>
17#include <asm/machdep.h>
18#include <asm/prom.h>
19#include <asm/sections.h>
20
21void machine_crash_shutdown(struct pt_regs *regs)
22{
23	if (ppc_md.machine_crash_shutdown)
24		ppc_md.machine_crash_shutdown(regs);
25	else
26		default_machine_crash_shutdown(regs);
27}
28
29/*
30 * Do what every setup is needed on image and the
31 * reboot code buffer to allow us to avoid allocations
32 * later.
33 */
34int machine_kexec_prepare(struct kimage *image)
35{
36	if (ppc_md.machine_kexec_prepare)
37		return ppc_md.machine_kexec_prepare(image);
38	else
39		return default_machine_kexec_prepare(image);
40}
41
42void machine_kexec_cleanup(struct kimage *image)
43{
44	if (ppc_md.machine_kexec_cleanup)
45		ppc_md.machine_kexec_cleanup(image);
46}
47
48void arch_crash_save_vmcoreinfo(void)
49{
50
51#ifdef CONFIG_NEED_MULTIPLE_NODES
52	VMCOREINFO_SYMBOL(node_data);
53	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
54#endif
55#ifndef CONFIG_NEED_MULTIPLE_NODES
56	VMCOREINFO_SYMBOL(contig_page_data);
57#endif
58}
59
60/*
61 * Do not allocate memory (or fail in any way) in machine_kexec().
62 * We are past the point of no return, committed to rebooting now.
63 */
64void machine_kexec(struct kimage *image)
65{
66	if (ppc_md.machine_kexec)
67		ppc_md.machine_kexec(image);
68	else
69		default_machine_kexec(image);
70
71	/* Fall back to normal restart if we're still alive. */
72	machine_restart(NULL);
73	for(;;);
74}
75
76void __init reserve_crashkernel(void)
77{
78	unsigned long long crash_size, crash_base;
79	int ret;
80
81	/* this is necessary because of lmb_phys_mem_size() */
82	lmb_analyze();
83
84	/* use common parsing */
85	ret = parse_crashkernel(boot_command_line, lmb_phys_mem_size(),
86			&crash_size, &crash_base);
87	if (ret == 0 && crash_size > 0) {
88		crashk_res.start = crash_base;
89		crashk_res.end = crash_base + crash_size - 1;
90	}
91
92	if (crashk_res.end == crashk_res.start) {
93		crashk_res.start = crashk_res.end = 0;
94		return;
95	}
96
97	/* We might have got these values via the command line or the
98	 * device tree, either way sanitise them now. */
99
100	crash_size = crashk_res.end - crashk_res.start + 1;
101
102#ifndef CONFIG_RELOCATABLE
103	if (crashk_res.start != KDUMP_KERNELBASE)
104		printk("Crash kernel location must be 0x%x\n",
105				KDUMP_KERNELBASE);
106
107	crashk_res.start = KDUMP_KERNELBASE;
108#else
109	if (!crashk_res.start) {
110		/*
111		 * unspecified address, choose a region of specified size
112		 * can overlap with initrd (ignoring corruption when retained)
113		 * ppc64 requires kernel and some stacks to be in first segemnt
114		 */
115		crashk_res.start = KDUMP_KERNELBASE;
116	}
117
118	crash_base = PAGE_ALIGN(crashk_res.start);
119	if (crash_base != crashk_res.start) {
120		printk("Crash kernel base must be aligned to 0x%lx\n",
121				PAGE_SIZE);
122		crashk_res.start = crash_base;
123	}
124
125#endif
126	crash_size = PAGE_ALIGN(crash_size);
127	crashk_res.end = crashk_res.start + crash_size - 1;
128
129	/* The crash region must not overlap the current kernel */
130	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
131		printk(KERN_WARNING
132			"Crash kernel can not overlap current kernel\n");
133		crashk_res.start = crashk_res.end = 0;
134		return;
135	}
136
137	/* Crash kernel trumps memory limit */
138	if (memory_limit && memory_limit <= crashk_res.end) {
139		memory_limit = crashk_res.end + 1;
140		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
141		       (unsigned long long)memory_limit);
142	}
143
144	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
145			"for crashkernel (System RAM: %ldMB)\n",
146			(unsigned long)(crash_size >> 20),
147			(unsigned long)(crashk_res.start >> 20),
148			(unsigned long)(lmb_phys_mem_size() >> 20));
149
150	lmb_reserve(crashk_res.start, crash_size);
151}
152
153int overlaps_crashkernel(unsigned long start, unsigned long size)
154{
155	return (start + size) > crashk_res.start && start <= crashk_res.end;
156}
157
158/* Values we need to export to the second kernel via the device tree. */
159static phys_addr_t kernel_end;
160static phys_addr_t crashk_size;
161
162static struct property kernel_end_prop = {
163	.name = "linux,kernel-end",
164	.length = sizeof(phys_addr_t),
165	.value = &kernel_end,
166};
167
168static struct property crashk_base_prop = {
169	.name = "linux,crashkernel-base",
170	.length = sizeof(phys_addr_t),
171	.value = &crashk_res.start,
172};
173
174static struct property crashk_size_prop = {
175	.name = "linux,crashkernel-size",
176	.length = sizeof(phys_addr_t),
177	.value = &crashk_size,
178};
179
180static void __init export_crashk_values(struct device_node *node)
181{
182	struct property *prop;
183
184	/* There might be existing crash kernel properties, but we can't
185	 * be sure what's in them, so remove them. */
186	prop = of_find_property(node, "linux,crashkernel-base", NULL);
187	if (prop)
188		prom_remove_property(node, prop);
189
190	prop = of_find_property(node, "linux,crashkernel-size", NULL);
191	if (prop)
192		prom_remove_property(node, prop);
193
194	if (crashk_res.start != 0) {
195		prom_add_property(node, &crashk_base_prop);
196		crashk_size = crashk_res.end - crashk_res.start + 1;
197		prom_add_property(node, &crashk_size_prop);
198	}
199}
200
201static int __init kexec_setup(void)
202{
203	struct device_node *node;
204	struct property *prop;
205
206	node = of_find_node_by_path("/chosen");
207	if (!node)
208		return -ENOENT;
209
210	/* remove any stale properties so ours can be found */
211	prop = of_find_property(node, kernel_end_prop.name, NULL);
212	if (prop)
213		prom_remove_property(node, prop);
214
215	/* information needed by userspace when using default_machine_kexec */
216	kernel_end = __pa(_end);
217	prom_add_property(node, &kernel_end_prop);
218
219	export_crashk_values(node);
220
221	of_node_put(node);
222	return 0;
223}
224late_initcall(kexec_setup);
225