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 
machine_kexec_mask_interrupts(void)24 void 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 
machine_crash_shutdown(struct pt_regs * regs)49 void 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  */
machine_kexec_prepare(struct kimage * image)59 int 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 
machine_kexec_cleanup(struct kimage * image)67 void machine_kexec_cleanup(struct kimage *image)
68 {
69 }
70 
arch_crash_save_vmcoreinfo(void)71 void 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  */
machine_kexec(struct kimage * image)87 void 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 
reserve_crashkernel(void)105 void __init reserve_crashkernel(void)
106 {
107 	unsigned long long crash_size, crash_base;
108 	int ret;
109 
110 	/* this is necessary because of memblock_phys_mem_size() */
111 	memblock_analyze();
112 
113 	/* use common parsing */
114 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
115 			&crash_size, &crash_base);
116 	if (ret == 0 && crash_size > 0) {
117 		crashk_res.start = crash_base;
118 		crashk_res.end = crash_base + crash_size - 1;
119 	}
120 
121 	if (crashk_res.end == crashk_res.start) {
122 		crashk_res.start = crashk_res.end = 0;
123 		return;
124 	}
125 
126 	/* We might have got these values via the command line or the
127 	 * device tree, either way sanitise them now. */
128 
129 	crash_size = crashk_res.end - crashk_res.start + 1;
130 
131 #ifndef CONFIG_RELOCATABLE
132 	if (crashk_res.start != KDUMP_KERNELBASE)
133 		printk("Crash kernel location must be 0x%x\n",
134 				KDUMP_KERNELBASE);
135 
136 	crashk_res.start = KDUMP_KERNELBASE;
137 #else
138 	if (!crashk_res.start) {
139 		/*
140 		 * unspecified address, choose a region of specified size
141 		 * can overlap with initrd (ignoring corruption when retained)
142 		 * ppc64 requires kernel and some stacks to be in first segemnt
143 		 */
144 		crashk_res.start = KDUMP_KERNELBASE;
145 	}
146 
147 	crash_base = PAGE_ALIGN(crashk_res.start);
148 	if (crash_base != crashk_res.start) {
149 		printk("Crash kernel base must be aligned to 0x%lx\n",
150 				PAGE_SIZE);
151 		crashk_res.start = crash_base;
152 	}
153 
154 #endif
155 	crash_size = PAGE_ALIGN(crash_size);
156 	crashk_res.end = crashk_res.start + crash_size - 1;
157 
158 	/* The crash region must not overlap the current kernel */
159 	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
160 		printk(KERN_WARNING
161 			"Crash kernel can not overlap current kernel\n");
162 		crashk_res.start = crashk_res.end = 0;
163 		return;
164 	}
165 
166 	/* Crash kernel trumps memory limit */
167 	if (memory_limit && memory_limit <= crashk_res.end) {
168 		memory_limit = crashk_res.end + 1;
169 		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
170 		       (unsigned long long)memory_limit);
171 	}
172 
173 	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
174 			"for crashkernel (System RAM: %ldMB)\n",
175 			(unsigned long)(crash_size >> 20),
176 			(unsigned long)(crashk_res.start >> 20),
177 			(unsigned long)(memblock_phys_mem_size() >> 20));
178 
179 	memblock_reserve(crashk_res.start, crash_size);
180 }
181 
overlaps_crashkernel(unsigned long start,unsigned long size)182 int overlaps_crashkernel(unsigned long start, unsigned long size)
183 {
184 	return (start + size) > crashk_res.start && start <= crashk_res.end;
185 }
186 
187 /* Values we need to export to the second kernel via the device tree. */
188 static phys_addr_t kernel_end;
189 static phys_addr_t crashk_size;
190 
191 static struct property kernel_end_prop = {
192 	.name = "linux,kernel-end",
193 	.length = sizeof(phys_addr_t),
194 	.value = &kernel_end,
195 };
196 
197 static struct property crashk_base_prop = {
198 	.name = "linux,crashkernel-base",
199 	.length = sizeof(phys_addr_t),
200 	.value = &crashk_res.start,
201 };
202 
203 static struct property crashk_size_prop = {
204 	.name = "linux,crashkernel-size",
205 	.length = sizeof(phys_addr_t),
206 	.value = &crashk_size,
207 };
208 
export_crashk_values(struct device_node * node)209 static void __init export_crashk_values(struct device_node *node)
210 {
211 	struct property *prop;
212 
213 	/* There might be existing crash kernel properties, but we can't
214 	 * be sure what's in them, so remove them. */
215 	prop = of_find_property(node, "linux,crashkernel-base", NULL);
216 	if (prop)
217 		prom_remove_property(node, prop);
218 
219 	prop = of_find_property(node, "linux,crashkernel-size", NULL);
220 	if (prop)
221 		prom_remove_property(node, prop);
222 
223 	if (crashk_res.start != 0) {
224 		prom_add_property(node, &crashk_base_prop);
225 		crashk_size = crashk_res.end - crashk_res.start + 1;
226 		prom_add_property(node, &crashk_size_prop);
227 	}
228 }
229 
kexec_setup(void)230 static int __init kexec_setup(void)
231 {
232 	struct device_node *node;
233 	struct property *prop;
234 
235 	node = of_find_node_by_path("/chosen");
236 	if (!node)
237 		return -ENOENT;
238 
239 	/* remove any stale properties so ours can be found */
240 	prop = of_find_property(node, kernel_end_prop.name, NULL);
241 	if (prop)
242 		prom_remove_property(node, prop);
243 
244 	/* information needed by userspace when using default_machine_kexec */
245 	kernel_end = __pa(_end);
246 	prom_add_property(node, &kernel_end_prop);
247 
248 	export_crashk_values(node);
249 
250 	of_node_put(node);
251 	return 0;
252 }
253 late_initcall(kexec_setup);
254