1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Code to handle transition of Linux booting another kernel.
4 *
5 * Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com>
6 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
7 * Copyright (C) 2005 IBM Corporation.
8 */
9
10 #include <linux/kexec.h>
11 #include <linux/reboot.h>
12 #include <linux/threads.h>
13 #include <linux/memblock.h>
14 #include <linux/of.h>
15 #include <linux/irq.h>
16 #include <linux/ftrace.h>
17
18 #include <asm/kdump.h>
19 #include <asm/machdep.h>
20 #include <asm/pgalloc.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 struct irq_desc *desc;
27
28 for_each_irq_desc(i, desc) {
29 struct irq_chip *chip;
30
31 chip = irq_desc_get_chip(desc);
32 if (!chip)
33 continue;
34
35 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
36 chip->irq_eoi(&desc->irq_data);
37
38 if (chip->irq_mask)
39 chip->irq_mask(&desc->irq_data);
40
41 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
42 chip->irq_disable(&desc->irq_data);
43 }
44 }
45
machine_crash_shutdown(struct pt_regs * regs)46 void machine_crash_shutdown(struct pt_regs *regs)
47 {
48 default_machine_crash_shutdown(regs);
49 }
50
51 /*
52 * Do what every setup is needed on image and the
53 * reboot code buffer to allow us to avoid allocations
54 * later.
55 */
machine_kexec_prepare(struct kimage * image)56 int machine_kexec_prepare(struct kimage *image)
57 {
58 if (ppc_md.machine_kexec_prepare)
59 return ppc_md.machine_kexec_prepare(image);
60 else
61 return default_machine_kexec_prepare(image);
62 }
63
machine_kexec_cleanup(struct kimage * image)64 void machine_kexec_cleanup(struct kimage *image)
65 {
66 }
67
arch_crash_save_vmcoreinfo(void)68 void arch_crash_save_vmcoreinfo(void)
69 {
70
71 #ifdef CONFIG_NEED_MULTIPLE_NODES
72 VMCOREINFO_SYMBOL(node_data);
73 VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
74 #endif
75 #ifndef CONFIG_NEED_MULTIPLE_NODES
76 VMCOREINFO_SYMBOL(contig_page_data);
77 #endif
78 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
79 VMCOREINFO_SYMBOL(vmemmap_list);
80 VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
81 VMCOREINFO_SYMBOL(mmu_psize_defs);
82 VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
83 VMCOREINFO_OFFSET(vmemmap_backing, list);
84 VMCOREINFO_OFFSET(vmemmap_backing, phys);
85 VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
86 VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
87 VMCOREINFO_OFFSET(mmu_psize_def, shift);
88 #endif
89 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
90 }
91
92 /*
93 * Do not allocate memory (or fail in any way) in machine_kexec().
94 * We are past the point of no return, committed to rebooting now.
95 */
machine_kexec(struct kimage * image)96 void machine_kexec(struct kimage *image)
97 {
98 int save_ftrace_enabled;
99
100 save_ftrace_enabled = __ftrace_enabled_save();
101 this_cpu_disable_ftrace();
102
103 if (ppc_md.machine_kexec)
104 ppc_md.machine_kexec(image);
105 else
106 default_machine_kexec(image);
107
108 this_cpu_enable_ftrace();
109 __ftrace_enabled_restore(save_ftrace_enabled);
110
111 /* Fall back to normal restart if we're still alive. */
112 machine_restart(NULL);
113 for(;;);
114 }
115
reserve_crashkernel(void)116 void __init reserve_crashkernel(void)
117 {
118 unsigned long long crash_size, crash_base, total_mem_sz;
119 int ret;
120
121 total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
122 /* use common parsing */
123 ret = parse_crashkernel(boot_command_line, total_mem_sz,
124 &crash_size, &crash_base);
125 if (ret == 0 && crash_size > 0) {
126 crashk_res.start = crash_base;
127 crashk_res.end = crash_base + crash_size - 1;
128 }
129
130 if (crashk_res.end == crashk_res.start) {
131 crashk_res.start = crashk_res.end = 0;
132 return;
133 }
134
135 /* We might have got these values via the command line or the
136 * device tree, either way sanitise them now. */
137
138 crash_size = resource_size(&crashk_res);
139
140 #ifndef CONFIG_NONSTATIC_KERNEL
141 if (crashk_res.start != KDUMP_KERNELBASE)
142 printk("Crash kernel location must be 0x%x\n",
143 KDUMP_KERNELBASE);
144
145 crashk_res.start = KDUMP_KERNELBASE;
146 #else
147 if (!crashk_res.start) {
148 #ifdef CONFIG_PPC64
149 /*
150 * On 64bit we split the RMO in half but cap it at half of
151 * a small SLB (128MB) since the crash kernel needs to place
152 * itself and some stacks to be in the first segment.
153 */
154 crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
155 #else
156 crashk_res.start = KDUMP_KERNELBASE;
157 #endif
158 }
159
160 crash_base = PAGE_ALIGN(crashk_res.start);
161 if (crash_base != crashk_res.start) {
162 printk("Crash kernel base must be aligned to 0x%lx\n",
163 PAGE_SIZE);
164 crashk_res.start = crash_base;
165 }
166
167 #endif
168 crash_size = PAGE_ALIGN(crash_size);
169 crashk_res.end = crashk_res.start + crash_size - 1;
170
171 /* The crash region must not overlap the current kernel */
172 if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
173 printk(KERN_WARNING
174 "Crash kernel can not overlap current kernel\n");
175 crashk_res.start = crashk_res.end = 0;
176 return;
177 }
178
179 /* Crash kernel trumps memory limit */
180 if (memory_limit && memory_limit <= crashk_res.end) {
181 memory_limit = crashk_res.end + 1;
182 total_mem_sz = memory_limit;
183 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
184 memory_limit);
185 }
186
187 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
188 "for crashkernel (System RAM: %ldMB)\n",
189 (unsigned long)(crash_size >> 20),
190 (unsigned long)(crashk_res.start >> 20),
191 (unsigned long)(total_mem_sz >> 20));
192
193 if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
194 memblock_reserve(crashk_res.start, crash_size)) {
195 pr_err("Failed to reserve memory for crashkernel!\n");
196 crashk_res.start = crashk_res.end = 0;
197 return;
198 }
199 }
200
overlaps_crashkernel(unsigned long start,unsigned long size)201 int overlaps_crashkernel(unsigned long start, unsigned long size)
202 {
203 return (start + size) > crashk_res.start && start <= crashk_res.end;
204 }
205
206 /* Values we need to export to the second kernel via the device tree. */
207 static phys_addr_t kernel_end;
208 static phys_addr_t crashk_base;
209 static phys_addr_t crashk_size;
210 static unsigned long long mem_limit;
211
212 static struct property kernel_end_prop = {
213 .name = "linux,kernel-end",
214 .length = sizeof(phys_addr_t),
215 .value = &kernel_end,
216 };
217
218 static struct property crashk_base_prop = {
219 .name = "linux,crashkernel-base",
220 .length = sizeof(phys_addr_t),
221 .value = &crashk_base
222 };
223
224 static struct property crashk_size_prop = {
225 .name = "linux,crashkernel-size",
226 .length = sizeof(phys_addr_t),
227 .value = &crashk_size,
228 };
229
230 static struct property memory_limit_prop = {
231 .name = "linux,memory-limit",
232 .length = sizeof(unsigned long long),
233 .value = &mem_limit,
234 };
235
236 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG)
237
export_crashk_values(struct device_node * node)238 static void __init export_crashk_values(struct device_node *node)
239 {
240 /* There might be existing crash kernel properties, but we can't
241 * be sure what's in them, so remove them. */
242 of_remove_property(node, of_find_property(node,
243 "linux,crashkernel-base", NULL));
244 of_remove_property(node, of_find_property(node,
245 "linux,crashkernel-size", NULL));
246
247 if (crashk_res.start != 0) {
248 crashk_base = cpu_to_be_ulong(crashk_res.start),
249 of_add_property(node, &crashk_base_prop);
250 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
251 of_add_property(node, &crashk_size_prop);
252 }
253
254 /*
255 * memory_limit is required by the kexec-tools to limit the
256 * crash regions to the actual memory used.
257 */
258 mem_limit = cpu_to_be_ulong(memory_limit);
259 of_update_property(node, &memory_limit_prop);
260 }
261
kexec_setup(void)262 static int __init kexec_setup(void)
263 {
264 struct device_node *node;
265
266 node = of_find_node_by_path("/chosen");
267 if (!node)
268 return -ENOENT;
269
270 /* remove any stale properties so ours can be found */
271 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
272
273 /* information needed by userspace when using default_machine_kexec */
274 kernel_end = cpu_to_be_ulong(__pa(_end));
275 of_add_property(node, &kernel_end_prop);
276
277 export_crashk_values(node);
278
279 of_node_put(node);
280 return 0;
281 }
282 late_initcall(kexec_setup);
283