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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
24void 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
46void 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 */
56int 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
64void machine_kexec_cleanup(struct kimage *image)
65{
66}
67
68void 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}
90
91/*
92 * Do not allocate memory (or fail in any way) in machine_kexec().
93 * We are past the point of no return, committed to rebooting now.
94 */
95void machine_kexec(struct kimage *image)
96{
97 int save_ftrace_enabled;
98
99 save_ftrace_enabled = __ftrace_enabled_save();
100 this_cpu_disable_ftrace();
101
102 if (ppc_md.machine_kexec)
103 ppc_md.machine_kexec(image);
104 else
105 default_machine_kexec(image);
106
107 this_cpu_enable_ftrace();
108 __ftrace_enabled_restore(save_ftrace_enabled);
109
110 /* Fall back to normal restart if we're still alive. */
111 machine_restart(NULL);
112 for(;;);
113}
114
115void __init reserve_crashkernel(void)
116{
117 unsigned long long crash_size, crash_base;
118 int ret;
119
120 /* use common parsing */
121 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
122 &crash_size, &crash_base);
123 if (ret == 0 && crash_size > 0) {
124 crashk_res.start = crash_base;
125 crashk_res.end = crash_base + crash_size - 1;
126 }
127
128 if (crashk_res.end == crashk_res.start) {
129 crashk_res.start = crashk_res.end = 0;
130 return;
131 }
132
133 /* We might have got these values via the command line or the
134 * device tree, either way sanitise them now. */
135
136 crash_size = resource_size(&crashk_res);
137
138#ifndef CONFIG_NONSTATIC_KERNEL
139 if (crashk_res.start != KDUMP_KERNELBASE)
140 printk("Crash kernel location must be 0x%x\n",
141 KDUMP_KERNELBASE);
142
143 crashk_res.start = KDUMP_KERNELBASE;
144#else
145 if (!crashk_res.start) {
146#ifdef CONFIG_PPC64
147 /*
148 * On 64bit we split the RMO in half but cap it at half of
149 * a small SLB (128MB) since the crash kernel needs to place
150 * itself and some stacks to be in the first segment.
151 */
152 crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
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 printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
181 memory_limit);
182 }
183
184 printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
185 "for crashkernel (System RAM: %ldMB)\n",
186 (unsigned long)(crash_size >> 20),
187 (unsigned long)(crashk_res.start >> 20),
188 (unsigned long)(memblock_phys_mem_size() >> 20));
189
190 if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
191 memblock_reserve(crashk_res.start, crash_size)) {
192 pr_err("Failed to reserve memory for crashkernel!\n");
193 crashk_res.start = crashk_res.end = 0;
194 return;
195 }
196}
197
198int overlaps_crashkernel(unsigned long start, unsigned long size)
199{
200 return (start + size) > crashk_res.start && start <= crashk_res.end;
201}
202
203/* Values we need to export to the second kernel via the device tree. */
204static phys_addr_t kernel_end;
205static phys_addr_t crashk_base;
206static phys_addr_t crashk_size;
207static unsigned long long mem_limit;
208
209static struct property kernel_end_prop = {
210 .name = "linux,kernel-end",
211 .length = sizeof(phys_addr_t),
212 .value = &kernel_end,
213};
214
215static struct property crashk_base_prop = {
216 .name = "linux,crashkernel-base",
217 .length = sizeof(phys_addr_t),
218 .value = &crashk_base
219};
220
221static struct property crashk_size_prop = {
222 .name = "linux,crashkernel-size",
223 .length = sizeof(phys_addr_t),
224 .value = &crashk_size,
225};
226
227static struct property memory_limit_prop = {
228 .name = "linux,memory-limit",
229 .length = sizeof(unsigned long long),
230 .value = &mem_limit,
231};
232
233#define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG)
234
235static void __init export_crashk_values(struct device_node *node)
236{
237 /* There might be existing crash kernel properties, but we can't
238 * be sure what's in them, so remove them. */
239 of_remove_property(node, of_find_property(node,
240 "linux,crashkernel-base", NULL));
241 of_remove_property(node, of_find_property(node,
242 "linux,crashkernel-size", NULL));
243
244 if (crashk_res.start != 0) {
245 crashk_base = cpu_to_be_ulong(crashk_res.start),
246 of_add_property(node, &crashk_base_prop);
247 crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
248 of_add_property(node, &crashk_size_prop);
249 }
250
251 /*
252 * memory_limit is required by the kexec-tools to limit the
253 * crash regions to the actual memory used.
254 */
255 mem_limit = cpu_to_be_ulong(memory_limit);
256 of_update_property(node, &memory_limit_prop);
257}
258
259static int __init kexec_setup(void)
260{
261 struct device_node *node;
262
263 node = of_find_node_by_path("/chosen");
264 if (!node)
265 return -ENOENT;
266
267 /* remove any stale properties so ours can be found */
268 of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
269
270 /* information needed by userspace when using default_machine_kexec */
271 kernel_end = cpu_to_be_ulong(__pa(_end));
272 of_add_property(node, &kernel_end_prop);
273
274 export_crashk_values(node);
275
276 of_node_put(node);
277 return 0;
278}
279late_initcall(kexec_setup);