1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * machine_kexec.c for kexec
4 * Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
5 */
6#include <linux/compiler.h>
7#include <linux/kexec.h>
8#include <linux/mm.h>
9#include <linux/delay.h>
10#include <linux/libfdt.h>
11
12#include <asm/cacheflush.h>
13#include <asm/page.h>
14
15extern const unsigned char relocate_new_kernel[];
16extern const size_t relocate_new_kernel_size;
17
18extern unsigned long kexec_start_address;
19extern unsigned long kexec_indirection_page;
20
21static unsigned long reboot_code_buffer;
22
23#ifdef CONFIG_SMP
24static void (*relocated_kexec_smp_wait)(void *);
25
26atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
27void (*_crash_smp_send_stop)(void) = NULL;
28#endif
29
30void (*_machine_kexec_shutdown)(void) = NULL;
31void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
32
33static void kexec_image_info(const struct kimage *kimage)
34{
35 unsigned long i;
36
37 pr_debug("kexec kimage info:\n");
38 pr_debug(" type: %d\n", kimage->type);
39 pr_debug(" start: %lx\n", kimage->start);
40 pr_debug(" head: %lx\n", kimage->head);
41 pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
42
43 for (i = 0; i < kimage->nr_segments; i++) {
44 pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
45 i,
46 kimage->segment[i].mem,
47 kimage->segment[i].mem + kimage->segment[i].memsz,
48 (unsigned long)kimage->segment[i].memsz,
49 (unsigned long)kimage->segment[i].memsz / PAGE_SIZE);
50 }
51}
52
53#ifdef CONFIG_UHI_BOOT
54
55static int uhi_machine_kexec_prepare(struct kimage *kimage)
56{
57 int i;
58
59 /*
60 * In case DTB file is not passed to the new kernel, a flat device
61 * tree will be created by kexec tool. It holds modified command
62 * line for the new kernel.
63 */
64 for (i = 0; i < kimage->nr_segments; i++) {
65 struct fdt_header fdt;
66
67 if (kimage->segment[i].memsz <= sizeof(fdt))
68 continue;
69
70 if (copy_from_user(&fdt, kimage->segment[i].buf, sizeof(fdt)))
71 continue;
72
73 if (fdt_check_header(&fdt))
74 continue;
75
76 kexec_args[0] = -2;
77 kexec_args[1] = (unsigned long)
78 phys_to_virt((unsigned long)kimage->segment[i].mem);
79 break;
80 }
81
82 return 0;
83}
84
85int (*_machine_kexec_prepare)(struct kimage *) = uhi_machine_kexec_prepare;
86
87#else
88
89int (*_machine_kexec_prepare)(struct kimage *) = NULL;
90
91#endif /* CONFIG_UHI_BOOT */
92
93int
94machine_kexec_prepare(struct kimage *kimage)
95{
96#ifdef CONFIG_SMP
97 if (!kexec_nonboot_cpu_func())
98 return -EINVAL;
99#endif
100
101 kexec_image_info(kimage);
102
103 if (_machine_kexec_prepare)
104 return _machine_kexec_prepare(kimage);
105
106 return 0;
107}
108
109void
110machine_kexec_cleanup(struct kimage *kimage)
111{
112}
113
114#ifdef CONFIG_SMP
115static void kexec_shutdown_secondary(void *param)
116{
117 int cpu = smp_processor_id();
118
119 if (!cpu_online(cpu))
120 return;
121
122 /* We won't be sent IPIs any more. */
123 set_cpu_online(cpu, online: false);
124
125 local_irq_disable();
126 while (!atomic_read(v: &kexec_ready_to_reboot))
127 cpu_relax();
128
129 kexec_reboot();
130
131 /* NOTREACHED */
132}
133#endif
134
135void
136machine_shutdown(void)
137{
138 if (_machine_kexec_shutdown)
139 _machine_kexec_shutdown();
140
141#ifdef CONFIG_SMP
142 smp_call_function(func: kexec_shutdown_secondary, NULL, wait: 0);
143
144 while (num_online_cpus() > 1) {
145 cpu_relax();
146 mdelay(1);
147 }
148#endif
149}
150
151void
152machine_crash_shutdown(struct pt_regs *regs)
153{
154 if (_machine_crash_shutdown)
155 _machine_crash_shutdown(regs);
156 else
157 default_machine_crash_shutdown(regs);
158}
159
160#ifdef CONFIG_SMP
161void kexec_nonboot_cpu_jump(void)
162{
163 local_flush_icache_range((unsigned long)relocated_kexec_smp_wait,
164 reboot_code_buffer + relocate_new_kernel_size);
165
166 relocated_kexec_smp_wait(NULL);
167}
168#endif
169
170void kexec_reboot(void)
171{
172 void (*do_kexec)(void) __noreturn;
173
174 /*
175 * We know we were online, and there will be no incoming IPIs at
176 * this point. Mark online again before rebooting so that the crash
177 * analysis tool will see us correctly.
178 */
179 set_cpu_online(smp_processor_id(), online: true);
180
181 /* Ensure remote CPUs observe that we're online before rebooting. */
182 smp_mb__after_atomic();
183
184#ifdef CONFIG_SMP
185 if (smp_processor_id() > 0) {
186 /*
187 * Instead of cpu_relax() or wait, this is needed for kexec
188 * smp reboot. Kdump usually doesn't require an smp new
189 * kernel, but kexec may do.
190 */
191 kexec_nonboot_cpu();
192
193 /* NOTREACHED */
194 }
195#endif
196
197 /*
198 * Make sure we get correct instructions written by the
199 * machine_kexec() CPU.
200 */
201 local_flush_icache_range(reboot_code_buffer,
202 reboot_code_buffer + relocate_new_kernel_size);
203
204 do_kexec = (void *)reboot_code_buffer;
205 do_kexec();
206}
207
208void
209machine_kexec(struct kimage *image)
210{
211 unsigned long entry;
212 unsigned long *ptr;
213
214 reboot_code_buffer =
215 (unsigned long)page_address(image->control_code_page);
216
217 kexec_start_address =
218 (unsigned long) phys_to_virt(address: image->start);
219
220 if (image->type == KEXEC_TYPE_DEFAULT) {
221 kexec_indirection_page =
222 (unsigned long) phys_to_virt(address: image->head & PAGE_MASK);
223 } else {
224 kexec_indirection_page = (unsigned long)&image->head;
225 }
226
227 memcpy((void*)reboot_code_buffer, relocate_new_kernel,
228 relocate_new_kernel_size);
229
230 /*
231 * The generic kexec code builds a page list with physical
232 * addresses. they are directly accessible through KSEG0 (or
233 * CKSEG0 or XPHYS if on 64bit system), hence the
234 * phys_to_virt() call.
235 */
236 for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
237 ptr = (entry & IND_INDIRECTION) ?
238 phys_to_virt(address: entry & PAGE_MASK) : ptr + 1) {
239 if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
240 *ptr & IND_DESTINATION)
241 *ptr = (unsigned long) phys_to_virt(address: *ptr);
242 }
243
244 /* Mark offline BEFORE disabling local irq. */
245 set_cpu_online(smp_processor_id(), online: false);
246
247 /*
248 * we do not want to be bothered.
249 */
250 local_irq_disable();
251
252 printk("Will call new kernel at %08lx\n", image->start);
253 printk("Bye ...\n");
254 /* Make reboot code buffer available to the boot CPU. */
255 __flush_cache_all();
256#ifdef CONFIG_SMP
257 /* All secondary cpus now may jump to kexec_wait cycle */
258 relocated_kexec_smp_wait = reboot_code_buffer +
259 (void *)(kexec_smp_wait - relocate_new_kernel);
260 smp_wmb();
261 atomic_set(v: &kexec_ready_to_reboot, i: 1);
262#endif
263 kexec_reboot();
264}
265

source code of linux/arch/mips/kernel/machine_kexec.c