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
machine_kexec_mask_interrupts(void)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(&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(&desc->irq_data))
43 chip->irq_disable(&desc->irq_data);
44 }
45 }
46
machine_crash_shutdown(struct pt_regs * regs)47 void machine_crash_shutdown(struct pt_regs *regs)
48 {
49 default_machine_crash_shutdown(regs);
50 }
51
machine_kexec_cleanup(struct kimage * image)52 void machine_kexec_cleanup(struct kimage *image)
53 {
54 }
55
arch_crash_save_vmcoreinfo(void)56 void arch_crash_save_vmcoreinfo(void)
57 {
58
59 #ifdef CONFIG_NUMA
60 VMCOREINFO_SYMBOL(node_data);
61 VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
62 #endif
63 #ifndef CONFIG_NUMA
64 VMCOREINFO_SYMBOL(contig_page_data);
65 #endif
66 #if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
67 VMCOREINFO_SYMBOL(vmemmap_list);
68 VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
69 VMCOREINFO_SYMBOL(mmu_psize_defs);
70 VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
71 VMCOREINFO_OFFSET(vmemmap_backing, list);
72 VMCOREINFO_OFFSET(vmemmap_backing, phys);
73 VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
74 VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
75 VMCOREINFO_OFFSET(mmu_psize_def, shift);
76 #endif
77 VMCOREINFO_SYMBOL(cur_cpu_spec);
78 VMCOREINFO_OFFSET(cpu_spec, mmu_features);
79 vmcoreinfo_append_str("NUMBER(RADIX_MMU)=%d\n", early_radix_enabled());
80 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
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 this_cpu_disable_ftrace();
93
94 if (ppc_md.machine_kexec)
95 ppc_md.machine_kexec(image);
96 else
97 default_machine_kexec(image);
98
99 this_cpu_enable_ftrace();
100 __ftrace_enabled_restore(save_ftrace_enabled);
101
102 /* Fall back to normal restart if we're still alive. */
103 machine_restart(NULL);
104 for(;;);
105 }
106
reserve_crashkernel(void)107 void __init reserve_crashkernel(void)
108 {
109 unsigned long long crash_size, crash_base, total_mem_sz;
110 int ret;
111
112 total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
113 /* use common parsing */
114 ret = parse_crashkernel(boot_command_line, total_mem_sz,
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 = resource_size(&crashk_res);
130
131 #ifndef CONFIG_NONSTATIC_KERNEL
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 #ifdef CONFIG_PPC64
140 /*
141 * On the LPAR platform place the crash kernel to mid of
142 * RMA size (max. of 512MB) to ensure the crash kernel
143 * gets enough space to place itself and some stack to be
144 * in the first segment. At the same time normal kernel
145 * also get enough space to allocate memory for essential
146 * system resource in the first segment. Keep the crash
147 * kernel starts at 128MB offset on other platforms.
148 */
149 if (firmware_has_feature(FW_FEATURE_LPAR))
150 crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_512M);
151 else
152 crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_128M);
153 #else
154 crashk_res.start = KDUMP_KERNELBASE;
155 #endif
156 }
157
158 crash_base = PAGE_ALIGN(crashk_res.start);
159 if (crash_base != crashk_res.start) {
160 printk("Crash kernel base must be aligned to 0x%lx\n",
161 PAGE_SIZE);
162 crashk_res.start = crash_base;
163 }
164
165 #endif
166 crash_size = PAGE_ALIGN(crash_size);
167 crashk_res.end = crashk_res.start + crash_size - 1;
168
169 /* The crash region must not overlap the current kernel */
170 if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
171 printk(KERN_WARNING
172 "Crash kernel can not overlap current kernel\n");
173 crashk_res.start = crashk_res.end = 0;
174 return;
175 }
176
177 /* Crash kernel trumps memory limit */
178 if (memory_limit && memory_limit <= crashk_res.end) {
179 memory_limit = crashk_res.end + 1;
180 total_mem_sz = memory_limit;
181 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
182 memory_limit);
183 }
184
185 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
186 "for crashkernel (System RAM: %ldMB)\n",
187 (unsigned long)(crash_size >> 20),
188 (unsigned long)(crashk_res.start >> 20),
189 (unsigned long)(total_mem_sz >> 20));
190
191 if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
192 memblock_reserve(crashk_res.start, crash_size)) {
193 pr_err("Failed to reserve memory for crashkernel!\n");
194 crashk_res.start = crashk_res.end = 0;
195 return;
196 }
197 }
198
overlaps_crashkernel(unsigned long start,unsigned long size)199 int __init overlaps_crashkernel(unsigned long start, unsigned long size)
200 {
201 return (start + size) > crashk_res.start && start <= crashk_res.end;
202 }
203
204 /* Values we need to export to the second kernel via the device tree. */
205 static phys_addr_t kernel_end;
206 static phys_addr_t crashk_base;
207 static phys_addr_t crashk_size;
208 static unsigned long long mem_limit;
209
210 static struct property kernel_end_prop = {
211 .name = "linux,kernel-end",
212 .length = sizeof(phys_addr_t),
213 .value = &kernel_end,
214 };
215
216 static struct property crashk_base_prop = {
217 .name = "linux,crashkernel-base",
218 .length = sizeof(phys_addr_t),
219 .value = &crashk_base
220 };
221
222 static struct property crashk_size_prop = {
223 .name = "linux,crashkernel-size",
224 .length = sizeof(phys_addr_t),
225 .value = &crashk_size,
226 };
227
228 static struct property memory_limit_prop = {
229 .name = "linux,memory-limit",
230 .length = sizeof(unsigned long long),
231 .value = &mem_limit,
232 };
233
234 #define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG)
235
export_crashk_values(struct device_node * node)236 static void __init export_crashk_values(struct device_node *node)
237 {
238 /* There might be existing crash kernel properties, but we can't
239 * be sure what's in them, so remove them. */
240 of_remove_property(node, of_find_property(node,
241 "linux,crashkernel-base", NULL));
242 of_remove_property(node, of_find_property(node,
243 "linux,crashkernel-size", NULL));
244
245 if (crashk_res.start != 0) {
246 crashk_base = cpu_to_be_ulong(crashk_res.start),
247 of_add_property(node, &crashk_base_prop);
248 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
249 of_add_property(node, &crashk_size_prop);
250 }
251
252 /*
253 * memory_limit is required by the kexec-tools to limit the
254 * crash regions to the actual memory used.
255 */
256 mem_limit = cpu_to_be_ulong(memory_limit);
257 of_update_property(node, &memory_limit_prop);
258 }
259
kexec_setup(void)260 static int __init kexec_setup(void)
261 {
262 struct device_node *node;
263
264 node = of_find_node_by_path("/chosen");
265 if (!node)
266 return -ENOENT;
267
268 /* remove any stale properties so ours can be found */
269 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
270
271 /* information needed by userspace when using default_machine_kexec */
272 kernel_end = cpu_to_be_ulong(__pa(_end));
273 of_add_property(node, &kernel_end_prop);
274
275 export_crashk_values(node);
276
277 of_node_put(node);
278 return 0;
279 }
280 late_initcall(kexec_setup);
281