machine_kexec.c revision 357574c48260c9177803a23b881d0af535670ec0 
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#include <linux/ftrace.h>
19
20#include <asm/machdep.h>
21#include <asm/prom.h>
22#include <asm/sections.h>
23
24void machine_kexec_mask_interrupts(void) {
25	unsigned int i;
26
27	for_each_irq(i) {
28		struct irq_desc *desc = irq_to_desc(i);
29
30		if (!desc || !desc->chip)
31			continue;
32
33		if (desc->chip->eoi &&
34		    desc->status & IRQ_INPROGRESS)
35			desc->chip->eoi(i);
36
37		if (desc->chip->mask)
38			desc->chip->mask(i);
39
40		if (desc->chip->disable &&
41		    !(desc->status & IRQ_DISABLED))
42			desc->chip->disable(i);
43	}
44}
45
46void machine_crash_shutdown(struct pt_regs *regs)
47{
48	default_machine_crash_shutdown(regs);
49}
50
51/*
52 * Do what every setup is needed on image and the
53 * reboot code buffer to allow us to avoid allocations
54 * later.
55 */
56int machine_kexec_prepare(struct kimage *image)
57{
58	if (ppc_md.machine_kexec_prepare)
59		return ppc_md.machine_kexec_prepare(image);
60	else
61		return default_machine_kexec_prepare(image);
62}
63
64void machine_kexec_cleanup(struct kimage *image)
65{
66}
67
68void arch_crash_save_vmcoreinfo(void)
69{
70
71#ifdef CONFIG_NEED_MULTIPLE_NODES
72	VMCOREINFO_SYMBOL(node_data);
73	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
74#endif
75#ifndef CONFIG_NEED_MULTIPLE_NODES
76	VMCOREINFO_SYMBOL(contig_page_data);
77#endif
78}
79
80/*
81 * Do not allocate memory (or fail in any way) in machine_kexec().
82 * We are past the point of no return, committed to rebooting now.
83 */
84void machine_kexec(struct kimage *image)
85{
86	int save_ftrace_enabled;
87
88	save_ftrace_enabled = __ftrace_enabled_save();
89
90	if (ppc_md.machine_kexec)
91		ppc_md.machine_kexec(image);
92	else
93		default_machine_kexec(image);
94
95	__ftrace_enabled_restore(save_ftrace_enabled);
96
97	/* Fall back to normal restart if we're still alive. */
98	machine_restart(NULL);
99	for(;;);
100}
101
102void __init reserve_crashkernel(void)
103{
104	unsigned long long crash_size, crash_base;
105	int ret;
106
107	/* this is necessary because of memblock_phys_mem_size() */
108	memblock_analyze();
109
110	/* use common parsing */
111	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
112			&crash_size, &crash_base);
113	if (ret == 0 && crash_size > 0) {
114		crashk_res.start = crash_base;
115		crashk_res.end = crash_base + crash_size - 1;
116	}
117
118	if (crashk_res.end == crashk_res.start) {
119		crashk_res.start = crashk_res.end = 0;
120		return;
121	}
122
123	/* We might have got these values via the command line or the
124	 * device tree, either way sanitise them now. */
125
126	crash_size = crashk_res.end - crashk_res.start + 1;
127
128#ifndef CONFIG_RELOCATABLE
129	if (crashk_res.start != KDUMP_KERNELBASE)
130		printk("Crash kernel location must be 0x%x\n",
131				KDUMP_KERNELBASE);
132
133	crashk_res.start = KDUMP_KERNELBASE;
134#else
135	if (!crashk_res.start) {
136		/*
137		 * unspecified address, choose a region of specified size
138		 * can overlap with initrd (ignoring corruption when retained)
139		 * ppc64 requires kernel and some stacks to be in first segemnt
140		 */
141		crashk_res.start = KDUMP_KERNELBASE;
142	}
143
144	crash_base = PAGE_ALIGN(crashk_res.start);
145	if (crash_base != crashk_res.start) {
146		printk("Crash kernel base must be aligned to 0x%lx\n",
147				PAGE_SIZE);
148		crashk_res.start = crash_base;
149	}
150
151#endif
152	crash_size = PAGE_ALIGN(crash_size);
153	crashk_res.end = crashk_res.start + crash_size - 1;
154
155	/* The crash region must not overlap the current kernel */
156	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
157		printk(KERN_WARNING
158			"Crash kernel can not overlap current kernel\n");
159		crashk_res.start = crashk_res.end = 0;
160		return;
161	}
162
163	/* Crash kernel trumps memory limit */
164	if (memory_limit && memory_limit <= crashk_res.end) {
165		memory_limit = crashk_res.end + 1;
166		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
167		       (unsigned long long)memory_limit);
168	}
169
170	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
171			"for crashkernel (System RAM: %ldMB)\n",
172			(unsigned long)(crash_size >> 20),
173			(unsigned long)(crashk_res.start >> 20),
174			(unsigned long)(memblock_phys_mem_size() >> 20));
175
176	memblock_reserve(crashk_res.start, crash_size);
177}
178
179int overlaps_crashkernel(unsigned long start, unsigned long size)
180{
181	return (start + size) > crashk_res.start && start <= crashk_res.end;
182}
183
184/* Values we need to export to the second kernel via the device tree. */
185static phys_addr_t kernel_end;
186static phys_addr_t crashk_size;
187
188static struct property kernel_end_prop = {
189	.name = "linux,kernel-end",
190	.length = sizeof(phys_addr_t),
191	.value = &kernel_end,
192};
193
194static struct property crashk_base_prop = {
195	.name = "linux,crashkernel-base",
196	.length = sizeof(phys_addr_t),
197	.value = &crashk_res.start,
198};
199
200static struct property crashk_size_prop = {
201	.name = "linux,crashkernel-size",
202	.length = sizeof(phys_addr_t),
203	.value = &crashk_size,
204};
205
206static void __init export_crashk_values(struct device_node *node)
207{
208	struct property *prop;
209
210	/* There might be existing crash kernel properties, but we can't
211	 * be sure what's in them, so remove them. */
212	prop = of_find_property(node, "linux,crashkernel-base", NULL);
213	if (prop)
214		prom_remove_property(node, prop);
215
216	prop = of_find_property(node, "linux,crashkernel-size", NULL);
217	if (prop)
218		prom_remove_property(node, prop);
219
220	if (crashk_res.start != 0) {
221		prom_add_property(node, &crashk_base_prop);
222		crashk_size = crashk_res.end - crashk_res.start + 1;
223		prom_add_property(node, &crashk_size_prop);
224	}
225}
226
227static int __init kexec_setup(void)
228{
229	struct device_node *node;
230	struct property *prop;
231
232	node = of_find_node_by_path("/chosen");
233	if (!node)
234		return -ENOENT;
235
236	/* remove any stale properties so ours can be found */
237	prop = of_find_property(node, kernel_end_prop.name, NULL);
238	if (prop)
239		prom_remove_property(node, prop);
240
241	/* information needed by userspace when using default_machine_kexec */
242	kernel_end = __pa(_end);
243	prom_add_property(node, &kernel_end_prop);
244
245	export_crashk_values(node);
246
247	of_node_put(node);
248	return 0;
249}
250late_initcall(kexec_setup);
251