machine_kexec.c revision c94868788cf26d5ad816646dd9af3cdf6fbd92fd 
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	default_machine_kexec(image);
89
90	/* Fall back to normal restart if we're still alive. */
91	machine_restart(NULL);
92	for(;;);
93}
94
95void __init reserve_crashkernel(void)
96{
97	unsigned long long crash_size, crash_base;
98	int ret;
99
100	/* this is necessary because of memblock_phys_mem_size() */
101	memblock_analyze();
102
103	/* use common parsing */
104	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
105			&crash_size, &crash_base);
106	if (ret == 0 && crash_size > 0) {
107		crashk_res.start = crash_base;
108		crashk_res.end = crash_base + crash_size - 1;
109	}
110
111	if (crashk_res.end == crashk_res.start) {
112		crashk_res.start = crashk_res.end = 0;
113		return;
114	}
115
116	/* We might have got these values via the command line or the
117	 * device tree, either way sanitise them now. */
118
119	crash_size = crashk_res.end - crashk_res.start + 1;
120
121#ifndef CONFIG_RELOCATABLE
122	if (crashk_res.start != KDUMP_KERNELBASE)
123		printk("Crash kernel location must be 0x%x\n",
124				KDUMP_KERNELBASE);
125
126	crashk_res.start = KDUMP_KERNELBASE;
127#else
128	if (!crashk_res.start) {
129		/*
130		 * unspecified address, choose a region of specified size
131		 * can overlap with initrd (ignoring corruption when retained)
132		 * ppc64 requires kernel and some stacks to be in first segemnt
133		 */
134		crashk_res.start = KDUMP_KERNELBASE;
135	}
136
137	crash_base = PAGE_ALIGN(crashk_res.start);
138	if (crash_base != crashk_res.start) {
139		printk("Crash kernel base must be aligned to 0x%lx\n",
140				PAGE_SIZE);
141		crashk_res.start = crash_base;
142	}
143
144#endif
145	crash_size = PAGE_ALIGN(crash_size);
146	crashk_res.end = crashk_res.start + crash_size - 1;
147
148	/* The crash region must not overlap the current kernel */
149	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
150		printk(KERN_WARNING
151			"Crash kernel can not overlap current kernel\n");
152		crashk_res.start = crashk_res.end = 0;
153		return;
154	}
155
156	/* Crash kernel trumps memory limit */
157	if (memory_limit && memory_limit <= crashk_res.end) {
158		memory_limit = crashk_res.end + 1;
159		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
160		       (unsigned long long)memory_limit);
161	}
162
163	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
164			"for crashkernel (System RAM: %ldMB)\n",
165			(unsigned long)(crash_size >> 20),
166			(unsigned long)(crashk_res.start >> 20),
167			(unsigned long)(memblock_phys_mem_size() >> 20));
168
169	memblock_reserve(crashk_res.start, crash_size);
170}
171
172int overlaps_crashkernel(unsigned long start, unsigned long size)
173{
174	return (start + size) > crashk_res.start && start <= crashk_res.end;
175}
176
177/* Values we need to export to the second kernel via the device tree. */
178static phys_addr_t kernel_end;
179static phys_addr_t crashk_size;
180
181static struct property kernel_end_prop = {
182	.name = "linux,kernel-end",
183	.length = sizeof(phys_addr_t),
184	.value = &kernel_end,
185};
186
187static struct property crashk_base_prop = {
188	.name = "linux,crashkernel-base",
189	.length = sizeof(phys_addr_t),
190	.value = &crashk_res.start,
191};
192
193static struct property crashk_size_prop = {
194	.name = "linux,crashkernel-size",
195	.length = sizeof(phys_addr_t),
196	.value = &crashk_size,
197};
198
199static void __init export_crashk_values(struct device_node *node)
200{
201	struct property *prop;
202
203	/* There might be existing crash kernel properties, but we can't
204	 * be sure what's in them, so remove them. */
205	prop = of_find_property(node, "linux,crashkernel-base", NULL);
206	if (prop)
207		prom_remove_property(node, prop);
208
209	prop = of_find_property(node, "linux,crashkernel-size", NULL);
210	if (prop)
211		prom_remove_property(node, prop);
212
213	if (crashk_res.start != 0) {
214		prom_add_property(node, &crashk_base_prop);
215		crashk_size = crashk_res.end - crashk_res.start + 1;
216		prom_add_property(node, &crashk_size_prop);
217	}
218}
219
220static int __init kexec_setup(void)
221{
222	struct device_node *node;
223	struct property *prop;
224
225	node = of_find_node_by_path("/chosen");
226	if (!node)
227		return -ENOENT;
228
229	/* remove any stale properties so ours can be found */
230	prop = of_find_property(node, kernel_end_prop.name, NULL);
231	if (prop)
232		prom_remove_property(node, prop);
233
234	/* information needed by userspace when using default_machine_kexec */
235	kernel_end = __pa(_end);
236	prom_add_property(node, &kernel_end_prop);
237
238	export_crashk_values(node);
239
240	of_node_put(node);
241	return 0;
242}
243late_initcall(kexec_setup);
244