machine_kexec.c revision 619b267724e8cc41072d650ae28114851dd8bf56 
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	if (ppc_md.machine_crash_shutdown)
48		ppc_md.machine_crash_shutdown(regs);
49	else
50		default_machine_crash_shutdown(regs);
51}
52
53/*
54 * Do what every setup is needed on image and the
55 * reboot code buffer to allow us to avoid allocations
56 * later.
57 */
58int machine_kexec_prepare(struct kimage *image)
59{
60	if (ppc_md.machine_kexec_prepare)
61		return ppc_md.machine_kexec_prepare(image);
62	else
63		return default_machine_kexec_prepare(image);
64}
65
66void machine_kexec_cleanup(struct kimage *image)
67{
68}
69
70void arch_crash_save_vmcoreinfo(void)
71{
72
73#ifdef CONFIG_NEED_MULTIPLE_NODES
74	VMCOREINFO_SYMBOL(node_data);
75	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
76#endif
77#ifndef CONFIG_NEED_MULTIPLE_NODES
78	VMCOREINFO_SYMBOL(contig_page_data);
79#endif
80}
81
82/*
83 * Do not allocate memory (or fail in any way) in machine_kexec().
84 * We are past the point of no return, committed to rebooting now.
85 */
86void machine_kexec(struct kimage *image)
87{
88	if (ppc_md.machine_kexec)
89		ppc_md.machine_kexec(image);
90	else
91		default_machine_kexec(image);
92
93	/* Fall back to normal restart if we're still alive. */
94	machine_restart(NULL);
95	for(;;);
96}
97
98void __init reserve_crashkernel(void)
99{
100	unsigned long long crash_size, crash_base;
101	int ret;
102
103	/* this is necessary because of memblock_phys_mem_size() */
104	memblock_analyze();
105
106	/* use common parsing */
107	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
108			&crash_size, &crash_base);
109	if (ret == 0 && crash_size > 0) {
110		crashk_res.start = crash_base;
111		crashk_res.end = crash_base + crash_size - 1;
112	}
113
114	if (crashk_res.end == crashk_res.start) {
115		crashk_res.start = crashk_res.end = 0;
116		return;
117	}
118
119	/* We might have got these values via the command line or the
120	 * device tree, either way sanitise them now. */
121
122	crash_size = crashk_res.end - crashk_res.start + 1;
123
124#ifndef CONFIG_RELOCATABLE
125	if (crashk_res.start != KDUMP_KERNELBASE)
126		printk("Crash kernel location must be 0x%x\n",
127				KDUMP_KERNELBASE);
128
129	crashk_res.start = KDUMP_KERNELBASE;
130#else
131	if (!crashk_res.start) {
132		/*
133		 * unspecified address, choose a region of specified size
134		 * can overlap with initrd (ignoring corruption when retained)
135		 * ppc64 requires kernel and some stacks to be in first segemnt
136		 */
137		crashk_res.start = KDUMP_KERNELBASE;
138	}
139
140	crash_base = PAGE_ALIGN(crashk_res.start);
141	if (crash_base != crashk_res.start) {
142		printk("Crash kernel base must be aligned to 0x%lx\n",
143				PAGE_SIZE);
144		crashk_res.start = crash_base;
145	}
146
147#endif
148	crash_size = PAGE_ALIGN(crash_size);
149	crashk_res.end = crashk_res.start + crash_size - 1;
150
151	/* The crash region must not overlap the current kernel */
152	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
153		printk(KERN_WARNING
154			"Crash kernel can not overlap current kernel\n");
155		crashk_res.start = crashk_res.end = 0;
156		return;
157	}
158
159	/* Crash kernel trumps memory limit */
160	if (memory_limit && memory_limit <= crashk_res.end) {
161		memory_limit = crashk_res.end + 1;
162		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
163		       (unsigned long long)memory_limit);
164	}
165
166	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
167			"for crashkernel (System RAM: %ldMB)\n",
168			(unsigned long)(crash_size >> 20),
169			(unsigned long)(crashk_res.start >> 20),
170			(unsigned long)(memblock_phys_mem_size() >> 20));
171
172	memblock_reserve(crashk_res.start, crash_size);
173}
174
175int overlaps_crashkernel(unsigned long start, unsigned long size)
176{
177	return (start + size) > crashk_res.start && start <= crashk_res.end;
178}
179
180/* Values we need to export to the second kernel via the device tree. */
181static phys_addr_t kernel_end;
182static phys_addr_t crashk_size;
183
184static struct property kernel_end_prop = {
185	.name = "linux,kernel-end",
186	.length = sizeof(phys_addr_t),
187	.value = &kernel_end,
188};
189
190static struct property crashk_base_prop = {
191	.name = "linux,crashkernel-base",
192	.length = sizeof(phys_addr_t),
193	.value = &crashk_res.start,
194};
195
196static struct property crashk_size_prop = {
197	.name = "linux,crashkernel-size",
198	.length = sizeof(phys_addr_t),
199	.value = &crashk_size,
200};
201
202static void __init export_crashk_values(struct device_node *node)
203{
204	struct property *prop;
205
206	/* There might be existing crash kernel properties, but we can't
207	 * be sure what's in them, so remove them. */
208	prop = of_find_property(node, "linux,crashkernel-base", NULL);
209	if (prop)
210		prom_remove_property(node, prop);
211
212	prop = of_find_property(node, "linux,crashkernel-size", NULL);
213	if (prop)
214		prom_remove_property(node, prop);
215
216	if (crashk_res.start != 0) {
217		prom_add_property(node, &crashk_base_prop);
218		crashk_size = crashk_res.end - crashk_res.start + 1;
219		prom_add_property(node, &crashk_size_prop);
220	}
221}
222
223static int __init kexec_setup(void)
224{
225	struct device_node *node;
226	struct property *prop;
227
228	node = of_find_node_by_path("/chosen");
229	if (!node)
230		return -ENOENT;
231
232	/* remove any stale properties so ours can be found */
233	prop = of_find_property(node, kernel_end_prop.name, NULL);
234	if (prop)
235		prom_remove_property(node, prop);
236
237	/* information needed by userspace when using default_machine_kexec */
238	kernel_end = __pa(_end);
239	prom_add_property(node, &kernel_end_prop);
240
241	export_crashk_values(node);
242
243	of_node_put(node);
244	return 0;
245}
246late_initcall(kexec_setup);
247