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