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/sections.h> |
22 | #include <asm/setup.h> |
23 | #include <asm/firmware.h> |
24 | |
25 | void machine_kexec_mask_interrupts(void) { |
26 | unsigned int i; |
27 | struct irq_desc *desc; |
28 | |
29 | for_each_irq_desc(i, desc) { |
30 | struct irq_chip *chip; |
31 | |
32 | chip = irq_desc_get_chip(desc); |
33 | if (!chip) |
34 | continue; |
35 | |
36 | if (chip->irq_eoi && irqd_irq_inprogress(d: &desc->irq_data)) |
37 | chip->irq_eoi(&desc->irq_data); |
38 | |
39 | if (chip->irq_mask) |
40 | chip->irq_mask(&desc->irq_data); |
41 | |
42 | if (chip->irq_disable && !irqd_irq_disabled(d: &desc->irq_data)) |
43 | chip->irq_disable(&desc->irq_data); |
44 | } |
45 | } |
46 | |
47 | #ifdef CONFIG_CRASH_DUMP |
48 | void machine_crash_shutdown(struct pt_regs *regs) |
49 | { |
50 | default_machine_crash_shutdown(regs); |
51 | } |
52 | #endif |
53 | |
54 | void machine_kexec_cleanup(struct kimage *image) |
55 | { |
56 | } |
57 | |
58 | /* |
59 | * Do not allocate memory (or fail in any way) in machine_kexec(). |
60 | * We are past the point of no return, committed to rebooting now. |
61 | */ |
62 | void machine_kexec(struct kimage *image) |
63 | { |
64 | int save_ftrace_enabled; |
65 | |
66 | save_ftrace_enabled = __ftrace_enabled_save(); |
67 | this_cpu_disable_ftrace(); |
68 | |
69 | if (ppc_md.machine_kexec) |
70 | ppc_md.machine_kexec(image); |
71 | else |
72 | default_machine_kexec(image); |
73 | |
74 | this_cpu_enable_ftrace(); |
75 | __ftrace_enabled_restore(enabled: save_ftrace_enabled); |
76 | |
77 | /* Fall back to normal restart if we're still alive. */ |
78 | machine_restart(NULL); |
79 | for(;;); |
80 | } |
81 | |
82 | #ifdef CONFIG_CRASH_RESERVE |
83 | void __init reserve_crashkernel(void) |
84 | { |
85 | unsigned long long crash_size, crash_base, total_mem_sz; |
86 | int ret; |
87 | |
88 | total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size(); |
89 | /* use common parsing */ |
90 | ret = parse_crashkernel(cmdline: boot_command_line, system_ram: total_mem_sz, |
91 | crash_size: &crash_size, crash_base: &crash_base, NULL, NULL); |
92 | if (ret == 0 && crash_size > 0) { |
93 | crashk_res.start = crash_base; |
94 | crashk_res.end = crash_base + crash_size - 1; |
95 | } |
96 | |
97 | if (crashk_res.end == crashk_res.start) { |
98 | crashk_res.start = crashk_res.end = 0; |
99 | return; |
100 | } |
101 | |
102 | /* We might have got these values via the command line or the |
103 | * device tree, either way sanitise them now. */ |
104 | |
105 | crash_size = resource_size(res: &crashk_res); |
106 | |
107 | #ifndef CONFIG_NONSTATIC_KERNEL |
108 | if (crashk_res.start != KDUMP_KERNELBASE) |
109 | printk("Crash kernel location must be 0x%x\n" , |
110 | KDUMP_KERNELBASE); |
111 | |
112 | crashk_res.start = KDUMP_KERNELBASE; |
113 | #else |
114 | if (!crashk_res.start) { |
115 | #ifdef CONFIG_PPC64 |
116 | /* |
117 | * On the LPAR platform place the crash kernel to mid of |
118 | * RMA size (max. of 512MB) to ensure the crash kernel |
119 | * gets enough space to place itself and some stack to be |
120 | * in the first segment. At the same time normal kernel |
121 | * also get enough space to allocate memory for essential |
122 | * system resource in the first segment. Keep the crash |
123 | * kernel starts at 128MB offset on other platforms. |
124 | */ |
125 | if (firmware_has_feature(FW_FEATURE_LPAR)) |
126 | crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_512M); |
127 | else |
128 | crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_128M); |
129 | #else |
130 | crashk_res.start = KDUMP_KERNELBASE; |
131 | #endif |
132 | } |
133 | |
134 | crash_base = PAGE_ALIGN(crashk_res.start); |
135 | if (crash_base != crashk_res.start) { |
136 | printk("Crash kernel base must be aligned to 0x%lx\n" , |
137 | PAGE_SIZE); |
138 | crashk_res.start = crash_base; |
139 | } |
140 | |
141 | #endif |
142 | crash_size = PAGE_ALIGN(crash_size); |
143 | crashk_res.end = crashk_res.start + crash_size - 1; |
144 | |
145 | /* The crash region must not overlap the current kernel */ |
146 | if (overlaps_crashkernel(__pa(_stext), _end - _stext)) { |
147 | printk(KERN_WARNING |
148 | "Crash kernel can not overlap current kernel\n" ); |
149 | crashk_res.start = crashk_res.end = 0; |
150 | return; |
151 | } |
152 | |
153 | /* Crash kernel trumps memory limit */ |
154 | if (memory_limit && memory_limit <= crashk_res.end) { |
155 | memory_limit = crashk_res.end + 1; |
156 | total_mem_sz = memory_limit; |
157 | printk("Adjusted memory limit for crashkernel, now 0x%llx\n" , |
158 | memory_limit); |
159 | } |
160 | |
161 | printk(KERN_INFO "Reserving %ldMB of memory at %ldMB " |
162 | "for crashkernel (System RAM: %ldMB)\n" , |
163 | (unsigned long)(crash_size >> 20), |
164 | (unsigned long)(crashk_res.start >> 20), |
165 | (unsigned long)(total_mem_sz >> 20)); |
166 | |
167 | if (!memblock_is_region_memory(base: crashk_res.start, size: crash_size) || |
168 | memblock_reserve(base: crashk_res.start, size: crash_size)) { |
169 | pr_err("Failed to reserve memory for crashkernel!\n" ); |
170 | crashk_res.start = crashk_res.end = 0; |
171 | return; |
172 | } |
173 | } |
174 | |
175 | int __init overlaps_crashkernel(unsigned long start, unsigned long size) |
176 | { |
177 | return (start + size) > crashk_res.start && start <= crashk_res.end; |
178 | } |
179 | |
180 | /* Values we need to export to the second kernel via the device tree. */ |
181 | static phys_addr_t kernel_end; |
182 | static phys_addr_t crashk_base; |
183 | static phys_addr_t crashk_size; |
184 | static unsigned long long mem_limit; |
185 | |
186 | static struct property kernel_end_prop = { |
187 | .name = "linux,kernel-end" , |
188 | .length = sizeof(phys_addr_t), |
189 | .value = &kernel_end, |
190 | }; |
191 | |
192 | static struct property crashk_base_prop = { |
193 | .name = "linux,crashkernel-base" , |
194 | .length = sizeof(phys_addr_t), |
195 | .value = &crashk_base |
196 | }; |
197 | |
198 | static struct property crashk_size_prop = { |
199 | .name = "linux,crashkernel-size" , |
200 | .length = sizeof(phys_addr_t), |
201 | .value = &crashk_size, |
202 | }; |
203 | |
204 | static struct property memory_limit_prop = { |
205 | .name = "linux,memory-limit" , |
206 | .length = sizeof(unsigned long long), |
207 | .value = &mem_limit, |
208 | }; |
209 | |
210 | #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG) |
211 | |
212 | static void __init export_crashk_values(struct device_node *node) |
213 | { |
214 | /* There might be existing crash kernel properties, but we can't |
215 | * be sure what's in them, so remove them. */ |
216 | of_remove_property(np: node, prop: of_find_property(np: node, |
217 | name: "linux,crashkernel-base" , NULL)); |
218 | of_remove_property(np: node, prop: of_find_property(np: node, |
219 | name: "linux,crashkernel-size" , NULL)); |
220 | |
221 | if (crashk_res.start != 0) { |
222 | crashk_base = cpu_to_be_ulong(crashk_res.start), |
223 | of_add_property(np: node, prop: &crashk_base_prop); |
224 | crashk_size = cpu_to_be_ulong(resource_size(&crashk_res)); |
225 | of_add_property(np: node, prop: &crashk_size_prop); |
226 | } |
227 | |
228 | /* |
229 | * memory_limit is required by the kexec-tools to limit the |
230 | * crash regions to the actual memory used. |
231 | */ |
232 | mem_limit = cpu_to_be_ulong(memory_limit); |
233 | of_update_property(np: node, newprop: &memory_limit_prop); |
234 | } |
235 | |
236 | static int __init kexec_setup(void) |
237 | { |
238 | struct device_node *node; |
239 | |
240 | node = of_find_node_by_path(path: "/chosen" ); |
241 | if (!node) |
242 | return -ENOENT; |
243 | |
244 | /* remove any stale properties so ours can be found */ |
245 | of_remove_property(np: node, prop: of_find_property(np: node, name: kernel_end_prop.name, NULL)); |
246 | |
247 | /* information needed by userspace when using default_machine_kexec */ |
248 | kernel_end = cpu_to_be_ulong(__pa(_end)); |
249 | of_add_property(np: node, prop: &kernel_end_prop); |
250 | |
251 | export_crashk_values(node); |
252 | |
253 | of_node_put(node); |
254 | return 0; |
255 | } |
256 | late_initcall(kexec_setup); |
257 | #endif /* CONFIG_CRASH_RESERVE */ |
258 | |