machine_kexec.c revision 1aadc0560f46530f8a0f11055285b876a8a31770 
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		struct irq_chip *chip;
30
31		if (!desc)
32			continue;
33
34		chip = irq_desc_get_chip(desc);
35		if (!chip)
36			continue;
37
38		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
39			chip->irq_eoi(&desc->irq_data);
40
41		if (chip->irq_mask)
42			chip->irq_mask(&desc->irq_data);
43
44		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
45			chip->irq_disable(&desc->irq_data);
46	}
47}
48
49void machine_crash_shutdown(struct pt_regs *regs)
50{
51	default_machine_crash_shutdown(regs);
52}
53
54/*
55 * Do what every setup is needed on image and the
56 * reboot code buffer to allow us to avoid allocations
57 * later.
58 */
59int machine_kexec_prepare(struct kimage *image)
60{
61	if (ppc_md.machine_kexec_prepare)
62		return ppc_md.machine_kexec_prepare(image);
63	else
64		return default_machine_kexec_prepare(image);
65}
66
67void machine_kexec_cleanup(struct kimage *image)
68{
69}
70
71void arch_crash_save_vmcoreinfo(void)
72{
73
74#ifdef CONFIG_NEED_MULTIPLE_NODES
75	VMCOREINFO_SYMBOL(node_data);
76	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
77#endif
78#ifndef CONFIG_NEED_MULTIPLE_NODES
79	VMCOREINFO_SYMBOL(contig_page_data);
80#endif
81}
82
83/*
84 * Do not allocate memory (or fail in any way) in machine_kexec().
85 * We are past the point of no return, committed to rebooting now.
86 */
87void machine_kexec(struct kimage *image)
88{
89	int save_ftrace_enabled;
90
91	save_ftrace_enabled = __ftrace_enabled_save();
92
93	if (ppc_md.machine_kexec)
94		ppc_md.machine_kexec(image);
95	else
96		default_machine_kexec(image);
97
98	__ftrace_enabled_restore(save_ftrace_enabled);
99
100	/* Fall back to normal restart if we're still alive. */
101	machine_restart(NULL);
102	for(;;);
103}
104
105void __init reserve_crashkernel(void)
106{
107	unsigned long long crash_size, crash_base;
108	int ret;
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 = resource_size(&crashk_res);
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#ifdef CONFIG_PPC64
137		/*
138		 * On 64bit we split the RMO in half but cap it at half of
139		 * a small SLB (128MB) since the crash kernel needs to place
140		 * itself and some stacks to be in the first segment.
141		 */
142		crashk_res.start = min(0x80000000ULL, (ppc64_rma_size / 2));
143#else
144		crashk_res.start = KDUMP_KERNELBASE;
145#endif
146	}
147
148	crash_base = PAGE_ALIGN(crashk_res.start);
149	if (crash_base != crashk_res.start) {
150		printk("Crash kernel base must be aligned to 0x%lx\n",
151				PAGE_SIZE);
152		crashk_res.start = crash_base;
153	}
154
155#endif
156	crash_size = PAGE_ALIGN(crash_size);
157	crashk_res.end = crashk_res.start + crash_size - 1;
158
159	/* The crash region must not overlap the current kernel */
160	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
161		printk(KERN_WARNING
162			"Crash kernel can not overlap current kernel\n");
163		crashk_res.start = crashk_res.end = 0;
164		return;
165	}
166
167	/* Crash kernel trumps memory limit */
168	if (memory_limit && memory_limit <= crashk_res.end) {
169		memory_limit = crashk_res.end + 1;
170		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
171		       (unsigned long long)memory_limit);
172	}
173
174	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
175			"for crashkernel (System RAM: %ldMB)\n",
176			(unsigned long)(crash_size >> 20),
177			(unsigned long)(crashk_res.start >> 20),
178			(unsigned long)(memblock_phys_mem_size() >> 20));
179
180	memblock_reserve(crashk_res.start, crash_size);
181}
182
183int overlaps_crashkernel(unsigned long start, unsigned long size)
184{
185	return (start + size) > crashk_res.start && start <= crashk_res.end;
186}
187
188/* Values we need to export to the second kernel via the device tree. */
189static phys_addr_t kernel_end;
190static phys_addr_t crashk_size;
191
192static struct property kernel_end_prop = {
193	.name = "linux,kernel-end",
194	.length = sizeof(phys_addr_t),
195	.value = &kernel_end,
196};
197
198static struct property crashk_base_prop = {
199	.name = "linux,crashkernel-base",
200	.length = sizeof(phys_addr_t),
201	.value = &crashk_res.start,
202};
203
204static struct property crashk_size_prop = {
205	.name = "linux,crashkernel-size",
206	.length = sizeof(phys_addr_t),
207	.value = &crashk_size,
208};
209
210static void __init export_crashk_values(struct device_node *node)
211{
212	struct property *prop;
213
214	/* There might be existing crash kernel properties, but we can't
215	 * be sure what's in them, so remove them. */
216	prop = of_find_property(node, "linux,crashkernel-base", NULL);
217	if (prop)
218		prom_remove_property(node, prop);
219
220	prop = of_find_property(node, "linux,crashkernel-size", NULL);
221	if (prop)
222		prom_remove_property(node, prop);
223
224	if (crashk_res.start != 0) {
225		prom_add_property(node, &crashk_base_prop);
226		crashk_size = resource_size(&crashk_res);
227		prom_add_property(node, &crashk_size_prop);
228	}
229}
230
231static int __init kexec_setup(void)
232{
233	struct device_node *node;
234	struct property *prop;
235
236	node = of_find_node_by_path("/chosen");
237	if (!node)
238		return -ENOENT;
239
240	/* remove any stale properties so ours can be found */
241	prop = of_find_property(node, kernel_end_prop.name, NULL);
242	if (prop)
243		prom_remove_property(node, prop);
244
245	/* information needed by userspace when using default_machine_kexec */
246	kernel_end = __pa(_end);
247	prom_add_property(node, &kernel_end_prop);
248
249	export_crashk_values(node);
250
251	of_node_put(node);
252	return 0;
253}
254late_initcall(kexec_setup);
255