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
machine_kexec_cleanup(struct kimage * image)51 void machine_kexec_cleanup(struct kimage *image)
52 {
53 }
54
arch_crash_save_vmcoreinfo(void)55 void arch_crash_save_vmcoreinfo(void)
56 {
57
58 #ifdef CONFIG_NUMA
59 VMCOREINFO_SYMBOL(node_data);
60 VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
61 #endif
62 #ifndef CONFIG_NUMA
63 VMCOREINFO_SYMBOL(contig_page_data);
64 #endif
65 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
66 VMCOREINFO_SYMBOL(vmemmap_list);
67 VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
68 VMCOREINFO_SYMBOL(mmu_psize_defs);
69 VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
70 VMCOREINFO_OFFSET(vmemmap_backing, list);
71 VMCOREINFO_OFFSET(vmemmap_backing, phys);
72 VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
73 VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
74 VMCOREINFO_OFFSET(mmu_psize_def, shift);
75 #endif
76 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
77 }
78
79 /*
80 * Do not allocate memory (or fail in any way) in machine_kexec().
81 * We are past the point of no return, committed to rebooting now.
82 */
machine_kexec(struct kimage * image)83 void machine_kexec(struct kimage *image)
84 {
85 int save_ftrace_enabled;
86
87 save_ftrace_enabled = __ftrace_enabled_save();
88 this_cpu_disable_ftrace();
89
90 if (ppc_md.machine_kexec)
91 ppc_md.machine_kexec(image);
92 else
93 default_machine_kexec(image);
94
95 this_cpu_enable_ftrace();
96 __ftrace_enabled_restore(save_ftrace_enabled);
97
98 /* Fall back to normal restart if we're still alive. */
99 machine_restart(NULL);
100 for(;;);
101 }
102
reserve_crashkernel(void)103 void __init reserve_crashkernel(void)
104 {
105 unsigned long long crash_size, crash_base, total_mem_sz;
106 int ret;
107
108 total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
109 /* use common parsing */
110 ret = parse_crashkernel(boot_command_line, total_mem_sz,
111 &crash_size, &crash_base);
112 if (ret == 0 && crash_size > 0) {
113 crashk_res.start = crash_base;
114 crashk_res.end = crash_base + crash_size - 1;
115 }
116
117 if (crashk_res.end == crashk_res.start) {
118 crashk_res.start = crashk_res.end = 0;
119 return;
120 }
121
122 /* We might have got these values via the command line or the
123 * device tree, either way sanitise them now. */
124
125 crash_size = resource_size(&crashk_res);
126
127 #ifndef CONFIG_NONSTATIC_KERNEL
128 if (crashk_res.start != KDUMP_KERNELBASE)
129 printk("Crash kernel location must be 0x%x\n",
130 KDUMP_KERNELBASE);
131
132 crashk_res.start = KDUMP_KERNELBASE;
133 #else
134 if (!crashk_res.start) {
135 #ifdef CONFIG_PPC64
136 /*
137 * On 64bit we split the RMO in half but cap it at half of
138 * a small SLB (128MB) since the crash kernel needs to place
139 * itself and some stacks to be in the first segment.
140 */
141 crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
142 #else
143 crashk_res.start = KDUMP_KERNELBASE;
144 #endif
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 total_mem_sz = memory_limit;
170 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
171 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)(total_mem_sz >> 20));
179
180 if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
181 memblock_reserve(crashk_res.start, crash_size)) {
182 pr_err("Failed to reserve memory for crashkernel!\n");
183 crashk_res.start = crashk_res.end = 0;
184 return;
185 }
186 }
187
overlaps_crashkernel(unsigned long start,unsigned long size)188 int overlaps_crashkernel(unsigned long start, unsigned long size)
189 {
190 return (start + size) > crashk_res.start && start <= crashk_res.end;
191 }
192
193 /* Values we need to export to the second kernel via the device tree. */
194 static phys_addr_t kernel_end;
195 static phys_addr_t crashk_base;
196 static phys_addr_t crashk_size;
197 static unsigned long long mem_limit;
198
199 static struct property kernel_end_prop = {
200 .name = "linux,kernel-end",
201 .length = sizeof(phys_addr_t),
202 .value = &kernel_end,
203 };
204
205 static struct property crashk_base_prop = {
206 .name = "linux,crashkernel-base",
207 .length = sizeof(phys_addr_t),
208 .value = &crashk_base
209 };
210
211 static struct property crashk_size_prop = {
212 .name = "linux,crashkernel-size",
213 .length = sizeof(phys_addr_t),
214 .value = &crashk_size,
215 };
216
217 static struct property memory_limit_prop = {
218 .name = "linux,memory-limit",
219 .length = sizeof(unsigned long long),
220 .value = &mem_limit,
221 };
222
223 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG)
224
export_crashk_values(struct device_node * node)225 static void __init export_crashk_values(struct device_node *node)
226 {
227 /* There might be existing crash kernel properties, but we can't
228 * be sure what's in them, so remove them. */
229 of_remove_property(node, of_find_property(node,
230 "linux,crashkernel-base", NULL));
231 of_remove_property(node, of_find_property(node,
232 "linux,crashkernel-size", NULL));
233
234 if (crashk_res.start != 0) {
235 crashk_base = cpu_to_be_ulong(crashk_res.start),
236 of_add_property(node, &crashk_base_prop);
237 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
238 of_add_property(node, &crashk_size_prop);
239 }
240
241 /*
242 * memory_limit is required by the kexec-tools to limit the
243 * crash regions to the actual memory used.
244 */
245 mem_limit = cpu_to_be_ulong(memory_limit);
246 of_update_property(node, &memory_limit_prop);
247 }
248
kexec_setup(void)249 static int __init kexec_setup(void)
250 {
251 struct device_node *node;
252
253 node = of_find_node_by_path("/chosen");
254 if (!node)
255 return -ENOENT;
256
257 /* remove any stale properties so ours can be found */
258 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
259
260 /* information needed by userspace when using default_machine_kexec */
261 kernel_end = cpu_to_be_ulong(__pa(_end));
262 of_add_property(node, &kernel_end_prop);
263
264 export_crashk_values(node);
265
266 of_node_put(node);
267 return 0;
268 }
269 late_initcall(kexec_setup);
270