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