machine_kexec.c revision c1f784e553490a2602567666fc79ff142cb4413b 
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/memblock.h>
16#include <linux/of.h>
17#include <linux/irq.h>
18
19#include <asm/machdep.h>
20#include <asm/prom.h>
21#include <asm/sections.h>
22
23void machine_kexec_mask_interrupts(void) {
24	unsigned int i;
25
26	for_each_irq(i) {
27		struct irq_desc *desc = irq_to_desc(i);
28
29		if (!desc || !desc->chip)
30			continue;
31
32		if (desc->chip->eoi &&
33		    desc->status & IRQ_INPROGRESS)
34			desc->chip->eoi(i);
35
36		if (desc->chip->mask)
37			desc->chip->mask(i);
38
39		if (desc->chip->disable &&
40		    !(desc->status & IRQ_DISABLED))
41			desc->chip->disable(i);
42	}
43}
44
45void machine_crash_shutdown(struct pt_regs *regs)
46{
47	default_machine_crash_shutdown(regs);
48}
49
50/*
51 * Do what every setup is needed on image and the
52 * reboot code buffer to allow us to avoid allocations
53 * later.
54 */
55int machine_kexec_prepare(struct kimage *image)
56{
57	if (ppc_md.machine_kexec_prepare)
58		return ppc_md.machine_kexec_prepare(image);
59	else
60		return default_machine_kexec_prepare(image);
61}
62
63void machine_kexec_cleanup(struct kimage *image)
64{
65}
66
67void arch_crash_save_vmcoreinfo(void)
68{
69
70#ifdef CONFIG_NEED_MULTIPLE_NODES
71	VMCOREINFO_SYMBOL(node_data);
72	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
73#endif
74#ifndef CONFIG_NEED_MULTIPLE_NODES
75	VMCOREINFO_SYMBOL(contig_page_data);
76#endif
77}
78
79/*
80 * Do not allocate memory (or fail in any way) in machine_kexec().
81 * We are past the point of no return, committed to rebooting now.
82 */
83void machine_kexec(struct kimage *image)
84{
85	default_machine_kexec(image);
86
87	/* Fall back to normal restart if we're still alive. */
88	machine_restart(NULL);
89	for(;;);
90}
91
92void __init reserve_crashkernel(void)
93{
94	unsigned long long crash_size, crash_base;
95	int ret;
96
97	/* this is necessary because of memblock_phys_mem_size() */
98	memblock_analyze();
99
100	/* use common parsing */
101	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
102			&crash_size, &crash_base);
103	if (ret == 0 && crash_size > 0) {
104		crashk_res.start = crash_base;
105		crashk_res.end = crash_base + crash_size - 1;
106	}
107
108	if (crashk_res.end == crashk_res.start) {
109		crashk_res.start = crashk_res.end = 0;
110		return;
111	}
112
113	/* We might have got these values via the command line or the
114	 * device tree, either way sanitise them now. */
115
116	crash_size = crashk_res.end - crashk_res.start + 1;
117
118#ifndef CONFIG_RELOCATABLE
119	if (crashk_res.start != KDUMP_KERNELBASE)
120		printk("Crash kernel location must be 0x%x\n",
121				KDUMP_KERNELBASE);
122
123	crashk_res.start = KDUMP_KERNELBASE;
124#else
125	if (!crashk_res.start) {
126		/*
127		 * unspecified address, choose a region of specified size
128		 * can overlap with initrd (ignoring corruption when retained)
129		 * ppc64 requires kernel and some stacks to be in first segemnt
130		 */
131		crashk_res.start = KDUMP_KERNELBASE;
132	}
133
134	crash_base = PAGE_ALIGN(crashk_res.start);
135	if (crash_base != crashk_res.start) {
136		printk("Crash kernel base must be aligned to 0x%lx\n",
137				PAGE_SIZE);
138		crashk_res.start = crash_base;
139	}
140
141#endif
142	crash_size = PAGE_ALIGN(crash_size);
143	crashk_res.end = crashk_res.start + crash_size - 1;
144
145	/* The crash region must not overlap the current kernel */
146	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
147		printk(KERN_WARNING
148			"Crash kernel can not overlap current kernel\n");
149		crashk_res.start = crashk_res.end = 0;
150		return;
151	}
152
153	/* Crash kernel trumps memory limit */
154	if (memory_limit && memory_limit <= crashk_res.end) {
155		memory_limit = crashk_res.end + 1;
156		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
157		       (unsigned long long)memory_limit);
158	}
159
160	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
161			"for crashkernel (System RAM: %ldMB)\n",
162			(unsigned long)(crash_size >> 20),
163			(unsigned long)(crashk_res.start >> 20),
164			(unsigned long)(memblock_phys_mem_size() >> 20));
165
166	memblock_reserve(crashk_res.start, crash_size);
167}
168
169int overlaps_crashkernel(unsigned long start, unsigned long size)
170{
171	return (start + size) > crashk_res.start && start <= crashk_res.end;
172}
173
174/* Values we need to export to the second kernel via the device tree. */
175static phys_addr_t kernel_end;
176static phys_addr_t crashk_size;
177
178static struct property kernel_end_prop = {
179	.name = "linux,kernel-end",
180	.length = sizeof(phys_addr_t),
181	.value = &kernel_end,
182};
183
184static struct property crashk_base_prop = {
185	.name = "linux,crashkernel-base",
186	.length = sizeof(phys_addr_t),
187	.value = &crashk_res.start,
188};
189
190static struct property crashk_size_prop = {
191	.name = "linux,crashkernel-size",
192	.length = sizeof(phys_addr_t),
193	.value = &crashk_size,
194};
195
196static void __init export_crashk_values(struct device_node *node)
197{
198	struct property *prop;
199
200	/* There might be existing crash kernel properties, but we can't
201	 * be sure what's in them, so remove them. */
202	prop = of_find_property(node, "linux,crashkernel-base", NULL);
203	if (prop)
204		prom_remove_property(node, prop);
205
206	prop = of_find_property(node, "linux,crashkernel-size", NULL);
207	if (prop)
208		prom_remove_property(node, prop);
209
210	if (crashk_res.start != 0) {
211		prom_add_property(node, &crashk_base_prop);
212		crashk_size = crashk_res.end - crashk_res.start + 1;
213		prom_add_property(node, &crashk_size_prop);
214	}
215}
216
217static int __init kexec_setup(void)
218{
219	struct device_node *node;
220	struct property *prop;
221
222	node = of_find_node_by_path("/chosen");
223	if (!node)
224		return -ENOENT;
225
226	/* remove any stale properties so ours can be found */
227	prop = of_find_property(node, kernel_end_prop.name, NULL);
228	if (prop)
229		prom_remove_property(node, prop);
230
231	/* information needed by userspace when using default_machine_kexec */
232	kernel_end = __pa(_end);
233	prom_add_property(node, &kernel_end_prop);
234
235	export_crashk_values(node);
236
237	of_node_put(node);
238	return 0;
239}
240late_initcall(kexec_setup);
241