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1/*
2 * kexec for arm64
3 *
4 * Copyright (C) Linaro.
5 * Copyright (C) Huawei Futurewei Technologies.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/interrupt.h>
13#include <linux/irq.h>
14#include <linux/kernel.h>
15#include <linux/kexec.h>
16#include <linux/page-flags.h>
17#include <linux/smp.h>
18
19#include <asm/cacheflush.h>
20#include <asm/cpu_ops.h>
21#include <asm/daifflags.h>
22#include <asm/memory.h>
23#include <asm/mmu.h>
24#include <asm/mmu_context.h>
25#include <asm/page.h>
26
27#include "cpu-reset.h"
28
29/* Global variables for the arm64_relocate_new_kernel routine. */
30extern const unsigned char arm64_relocate_new_kernel[];
31extern const unsigned long arm64_relocate_new_kernel_size;
32
33/**
34 * kexec_image_info - For debugging output.
35 */
36#define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i)
37static void _kexec_image_info(const char *func, int line,
38 const struct kimage *kimage)
39{
40 unsigned long i;
41
42 pr_debug("%s:%d:\n", func, line);
43 pr_debug(" kexec kimage info:\n");
44 pr_debug(" type: %d\n", kimage->type);
45 pr_debug(" start: %lx\n", kimage->start);
46 pr_debug(" head: %lx\n", kimage->head);
47 pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
48
49 for (i = 0; i < kimage->nr_segments; i++) {
50 pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
51 i,
52 kimage->segment[i].mem,
53 kimage->segment[i].mem + kimage->segment[i].memsz,
54 kimage->segment[i].memsz,
55 kimage->segment[i].memsz / PAGE_SIZE);
56 }
57}
58
59void machine_kexec_cleanup(struct kimage *kimage)
60{
61 /* Empty routine needed to avoid build errors. */
62}
63
64/**
65 * machine_kexec_prepare - Prepare for a kexec reboot.
66 *
67 * Called from the core kexec code when a kernel image is loaded.
68 * Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus
69 * are stuck in the kernel. This avoids a panic once we hit machine_kexec().
70 */
71int machine_kexec_prepare(struct kimage *kimage)
72{
73 kexec_image_info(kimage);
74
75 if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
76 pr_err("Can't kexec: CPUs are stuck in the kernel.\n");
77 return -EBUSY;
78 }
79
80 return 0;
81}
82
83/**
84 * kexec_list_flush - Helper to flush the kimage list and source pages to PoC.
85 */
86static void kexec_list_flush(struct kimage *kimage)
87{
88 kimage_entry_t *entry;
89
90 for (entry = &kimage->head; ; entry++) {
91 unsigned int flag;
92 void *addr;
93
94 /* flush the list entries. */
95 __flush_dcache_area(entry, sizeof(kimage_entry_t));
96
97 flag = *entry & IND_FLAGS;
98 if (flag == IND_DONE)
99 break;
100
101 addr = phys_to_virt(*entry & PAGE_MASK);
102
103 switch (flag) {
104 case IND_INDIRECTION:
105 /* Set entry point just before the new list page. */
106 entry = (kimage_entry_t *)addr - 1;
107 break;
108 case IND_SOURCE:
109 /* flush the source pages. */
110 __flush_dcache_area(addr, PAGE_SIZE);
111 break;
112 case IND_DESTINATION:
113 break;
114 default:
115 BUG();
116 }
117 }
118}
119
120/**
121 * kexec_segment_flush - Helper to flush the kimage segments to PoC.
122 */
123static void kexec_segment_flush(const struct kimage *kimage)
124{
125 unsigned long i;
126
127 pr_debug("%s:\n", __func__);
128
129 for (i = 0; i < kimage->nr_segments; i++) {
130 pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
131 i,
132 kimage->segment[i].mem,
133 kimage->segment[i].mem + kimage->segment[i].memsz,
134 kimage->segment[i].memsz,
135 kimage->segment[i].memsz / PAGE_SIZE);
136
137 __flush_dcache_area(phys_to_virt(kimage->segment[i].mem),
138 kimage->segment[i].memsz);
139 }
140}
141
142/**
143 * machine_kexec - Do the kexec reboot.
144 *
145 * Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC.
146 */
147void machine_kexec(struct kimage *kimage)
148{
149 phys_addr_t reboot_code_buffer_phys;
150 void *reboot_code_buffer;
151 bool in_kexec_crash = (kimage == kexec_crash_image);
152 bool stuck_cpus = cpus_are_stuck_in_kernel();
153
154 /*
155 * New cpus may have become stuck_in_kernel after we loaded the image.
156 */
157 BUG_ON(!in_kexec_crash && (stuck_cpus || (num_online_cpus() > 1)));
158 WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()),
159 "Some CPUs may be stale, kdump will be unreliable.\n");
160
161 reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
162 reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys);
163
164 kexec_image_info(kimage);
165
166 pr_debug("%s:%d: control_code_page: %p\n", __func__, __LINE__,
167 kimage->control_code_page);
168 pr_debug("%s:%d: reboot_code_buffer_phys: %pa\n", __func__, __LINE__,
169 &reboot_code_buffer_phys);
170 pr_debug("%s:%d: reboot_code_buffer: %p\n", __func__, __LINE__,
171 reboot_code_buffer);
172 pr_debug("%s:%d: relocate_new_kernel: %p\n", __func__, __LINE__,
173 arm64_relocate_new_kernel);
174 pr_debug("%s:%d: relocate_new_kernel_size: 0x%lx(%lu) bytes\n",
175 __func__, __LINE__, arm64_relocate_new_kernel_size,
176 arm64_relocate_new_kernel_size);
177
178 /*
179 * Copy arm64_relocate_new_kernel to the reboot_code_buffer for use
180 * after the kernel is shut down.
181 */
182 memcpy(reboot_code_buffer, arm64_relocate_new_kernel,
183 arm64_relocate_new_kernel_size);
184
185 /* Flush the reboot_code_buffer in preparation for its execution. */
186 __flush_dcache_area(reboot_code_buffer, arm64_relocate_new_kernel_size);
187 flush_icache_range((uintptr_t)reboot_code_buffer,
188 arm64_relocate_new_kernel_size);
189
190 /* Flush the kimage list and its buffers. */
191 kexec_list_flush(kimage);
192
193 /* Flush the new image if already in place. */
194 if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE))
195 kexec_segment_flush(kimage);
196
197 pr_info("Bye!\n");
198
199 local_daif_mask();
200
201 /*
202 * cpu_soft_restart will shutdown the MMU, disable data caches, then
203 * transfer control to the reboot_code_buffer which contains a copy of
204 * the arm64_relocate_new_kernel routine. arm64_relocate_new_kernel
205 * uses physical addressing to relocate the new image to its final
206 * position and transfers control to the image entry point when the
207 * relocation is complete.
208 */
209
210 cpu_soft_restart(kimage != kexec_crash_image,
211 reboot_code_buffer_phys, kimage->head, kimage->start, 0);
212
213 BUG(); /* Should never get here. */
214}
215
216static void machine_kexec_mask_interrupts(void)
217{
218 unsigned int i;
219 struct irq_desc *desc;
220
221 for_each_irq_desc(i, desc) {
222 struct irq_chip *chip;
223 int ret;
224
225 chip = irq_desc_get_chip(desc);
226 if (!chip)
227 continue;
228
229 /*
230 * First try to remove the active state. If this
231 * fails, try to EOI the interrupt.
232 */
233 ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
234
235 if (ret && irqd_irq_inprogress(&desc->irq_data) &&
236 chip->irq_eoi)
237 chip->irq_eoi(&desc->irq_data);
238
239 if (chip->irq_mask)
240 chip->irq_mask(&desc->irq_data);
241
242 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
243 chip->irq_disable(&desc->irq_data);
244 }
245}
246
247/**
248 * machine_crash_shutdown - shutdown non-crashing cpus and save registers
249 */
250void machine_crash_shutdown(struct pt_regs *regs)
251{
252 local_irq_disable();
253
254 /* shutdown non-crashing cpus */
255 crash_smp_send_stop();
256
257 /* for crashing cpu */
258 crash_save_cpu(regs, smp_processor_id());
259 machine_kexec_mask_interrupts();
260
261 pr_info("Starting crashdump kernel...\n");
262}
263
264void arch_kexec_protect_crashkres(void)
265{
266 int i;
267
268 kexec_segment_flush(kexec_crash_image);
269
270 for (i = 0; i < kexec_crash_image->nr_segments; i++)
271 set_memory_valid(
272 __phys_to_virt(kexec_crash_image->segment[i].mem),
273 kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0);
274}
275
276void arch_kexec_unprotect_crashkres(void)
277{
278 int i;
279
280 for (i = 0; i < kexec_crash_image->nr_segments; i++)
281 set_memory_valid(
282 __phys_to_virt(kexec_crash_image->segment[i].mem),
283 kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1);
284}
285
286#ifdef CONFIG_HIBERNATION
287/*
288 * To preserve the crash dump kernel image, the relevant memory segments
289 * should be mapped again around the hibernation.
290 */
291void crash_prepare_suspend(void)
292{
293 if (kexec_crash_image)
294 arch_kexec_unprotect_crashkres();
295}
296
297void crash_post_resume(void)
298{
299 if (kexec_crash_image)
300 arch_kexec_protect_crashkres();
301}
302
303/*
304 * crash_is_nosave
305 *
306 * Return true only if a page is part of reserved memory for crash dump kernel,
307 * but does not hold any data of loaded kernel image.
308 *
309 * Note that all the pages in crash dump kernel memory have been initially
310 * marked as Reserved in kexec_reserve_crashkres_pages().
311 *
312 * In hibernation, the pages which are Reserved and yet "nosave" are excluded
313 * from the hibernation iamge. crash_is_nosave() does thich check for crash
314 * dump kernel and will reduce the total size of hibernation image.
315 */
316
317bool crash_is_nosave(unsigned long pfn)
318{
319 int i;
320 phys_addr_t addr;
321
322 if (!crashk_res.end)
323 return false;
324
325 /* in reserved memory? */
326 addr = __pfn_to_phys(pfn);
327 if ((addr < crashk_res.start) || (crashk_res.end < addr))
328 return false;
329
330 if (!kexec_crash_image)
331 return true;
332
333 /* not part of loaded kernel image? */
334 for (i = 0; i < kexec_crash_image->nr_segments; i++)
335 if (addr >= kexec_crash_image->segment[i].mem &&
336 addr < (kexec_crash_image->segment[i].mem +
337 kexec_crash_image->segment[i].memsz))
338 return false;
339
340 return true;
341}
342
343void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
344{
345 unsigned long addr;
346 struct page *page;
347
348 for (addr = begin; addr < end; addr += PAGE_SIZE) {
349 page = phys_to_page(addr);
350 ClearPageReserved(page);
351 free_reserved_page(page);
352 }
353}
354#endif /* CONFIG_HIBERNATION */
355
356void arch_crash_save_vmcoreinfo(void)
357{
358 VMCOREINFO_NUMBER(VA_BITS);
359 /* Please note VMCOREINFO_NUMBER() uses "%d", not "%x" */
360 vmcoreinfo_append_str("NUMBER(kimage_voffset)=0x%llx\n",
361 kimage_voffset);
362 vmcoreinfo_append_str("NUMBER(PHYS_OFFSET)=0x%llx\n",
363 PHYS_OFFSET);
364}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * kexec for arm64
4 *
5 * Copyright (C) Linaro.
6 * Copyright (C) Huawei Futurewei Technologies.
7 */
8
9#include <linux/interrupt.h>
10#include <linux/irq.h>
11#include <linux/kernel.h>
12#include <linux/kexec.h>
13#include <linux/page-flags.h>
14#include <linux/set_memory.h>
15#include <linux/smp.h>
16
17#include <asm/cacheflush.h>
18#include <asm/cpu_ops.h>
19#include <asm/daifflags.h>
20#include <asm/memory.h>
21#include <asm/mmu.h>
22#include <asm/mmu_context.h>
23#include <asm/page.h>
24
25#include "cpu-reset.h"
26
27/* Global variables for the arm64_relocate_new_kernel routine. */
28extern const unsigned char arm64_relocate_new_kernel[];
29extern const unsigned long arm64_relocate_new_kernel_size;
30
31/**
32 * kexec_image_info - For debugging output.
33 */
34#define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i)
35static void _kexec_image_info(const char *func, int line,
36 const struct kimage *kimage)
37{
38 unsigned long i;
39
40 pr_debug("%s:%d:\n", func, line);
41 pr_debug(" kexec kimage info:\n");
42 pr_debug(" type: %d\n", kimage->type);
43 pr_debug(" start: %lx\n", kimage->start);
44 pr_debug(" head: %lx\n", kimage->head);
45 pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
46 pr_debug(" kern_reloc: %pa\n", &kimage->arch.kern_reloc);
47
48 for (i = 0; i < kimage->nr_segments; i++) {
49 pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
50 i,
51 kimage->segment[i].mem,
52 kimage->segment[i].mem + kimage->segment[i].memsz,
53 kimage->segment[i].memsz,
54 kimage->segment[i].memsz / PAGE_SIZE);
55 }
56}
57
58void machine_kexec_cleanup(struct kimage *kimage)
59{
60 /* Empty routine needed to avoid build errors. */
61}
62
63int machine_kexec_post_load(struct kimage *kimage)
64{
65 void *reloc_code = page_to_virt(kimage->control_code_page);
66
67 memcpy(reloc_code, arm64_relocate_new_kernel,
68 arm64_relocate_new_kernel_size);
69 kimage->arch.kern_reloc = __pa(reloc_code);
70 kexec_image_info(kimage);
71
72 /*
73 * For execution with the MMU off, reloc_code needs to be cleaned to the
74 * PoC and invalidated from the I-cache.
75 */
76 dcache_clean_inval_poc((unsigned long)reloc_code,
77 (unsigned long)reloc_code +
78 arm64_relocate_new_kernel_size);
79 icache_inval_pou((uintptr_t)reloc_code,
80 (uintptr_t)reloc_code +
81 arm64_relocate_new_kernel_size);
82
83 return 0;
84}
85
86/**
87 * machine_kexec_prepare - Prepare for a kexec reboot.
88 *
89 * Called from the core kexec code when a kernel image is loaded.
90 * Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus
91 * are stuck in the kernel. This avoids a panic once we hit machine_kexec().
92 */
93int machine_kexec_prepare(struct kimage *kimage)
94{
95 if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
96 pr_err("Can't kexec: CPUs are stuck in the kernel.\n");
97 return -EBUSY;
98 }
99
100 return 0;
101}
102
103/**
104 * kexec_list_flush - Helper to flush the kimage list and source pages to PoC.
105 */
106static void kexec_list_flush(struct kimage *kimage)
107{
108 kimage_entry_t *entry;
109
110 for (entry = &kimage->head; ; entry++) {
111 unsigned int flag;
112 unsigned long addr;
113
114 /* flush the list entries. */
115 dcache_clean_inval_poc((unsigned long)entry,
116 (unsigned long)entry +
117 sizeof(kimage_entry_t));
118
119 flag = *entry & IND_FLAGS;
120 if (flag == IND_DONE)
121 break;
122
123 addr = (unsigned long)phys_to_virt(*entry & PAGE_MASK);
124
125 switch (flag) {
126 case IND_INDIRECTION:
127 /* Set entry point just before the new list page. */
128 entry = (kimage_entry_t *)addr - 1;
129 break;
130 case IND_SOURCE:
131 /* flush the source pages. */
132 dcache_clean_inval_poc(addr, addr + PAGE_SIZE);
133 break;
134 case IND_DESTINATION:
135 break;
136 default:
137 BUG();
138 }
139 }
140}
141
142/**
143 * kexec_segment_flush - Helper to flush the kimage segments to PoC.
144 */
145static void kexec_segment_flush(const struct kimage *kimage)
146{
147 unsigned long i;
148
149 pr_debug("%s:\n", __func__);
150
151 for (i = 0; i < kimage->nr_segments; i++) {
152 pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
153 i,
154 kimage->segment[i].mem,
155 kimage->segment[i].mem + kimage->segment[i].memsz,
156 kimage->segment[i].memsz,
157 kimage->segment[i].memsz / PAGE_SIZE);
158
159 dcache_clean_inval_poc(
160 (unsigned long)phys_to_virt(kimage->segment[i].mem),
161 (unsigned long)phys_to_virt(kimage->segment[i].mem) +
162 kimage->segment[i].memsz);
163 }
164}
165
166/**
167 * machine_kexec - Do the kexec reboot.
168 *
169 * Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC.
170 */
171void machine_kexec(struct kimage *kimage)
172{
173 bool in_kexec_crash = (kimage == kexec_crash_image);
174 bool stuck_cpus = cpus_are_stuck_in_kernel();
175
176 /*
177 * New cpus may have become stuck_in_kernel after we loaded the image.
178 */
179 BUG_ON(!in_kexec_crash && (stuck_cpus || (num_online_cpus() > 1)));
180 WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()),
181 "Some CPUs may be stale, kdump will be unreliable.\n");
182
183 /* Flush the kimage list and its buffers. */
184 kexec_list_flush(kimage);
185
186 /* Flush the new image if already in place. */
187 if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE))
188 kexec_segment_flush(kimage);
189
190 pr_info("Bye!\n");
191
192 local_daif_mask();
193
194 /*
195 * cpu_soft_restart will shutdown the MMU, disable data caches, then
196 * transfer control to the kern_reloc which contains a copy of
197 * the arm64_relocate_new_kernel routine. arm64_relocate_new_kernel
198 * uses physical addressing to relocate the new image to its final
199 * position and transfers control to the image entry point when the
200 * relocation is complete.
201 * In kexec case, kimage->start points to purgatory assuming that
202 * kernel entry and dtb address are embedded in purgatory by
203 * userspace (kexec-tools).
204 * In kexec_file case, the kernel starts directly without purgatory.
205 */
206 cpu_soft_restart(kimage->arch.kern_reloc, kimage->head, kimage->start,
207 kimage->arch.dtb_mem);
208
209 BUG(); /* Should never get here. */
210}
211
212static void machine_kexec_mask_interrupts(void)
213{
214 unsigned int i;
215 struct irq_desc *desc;
216
217 for_each_irq_desc(i, desc) {
218 struct irq_chip *chip;
219 int ret;
220
221 chip = irq_desc_get_chip(desc);
222 if (!chip)
223 continue;
224
225 /*
226 * First try to remove the active state. If this
227 * fails, try to EOI the interrupt.
228 */
229 ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
230
231 if (ret && irqd_irq_inprogress(&desc->irq_data) &&
232 chip->irq_eoi)
233 chip->irq_eoi(&desc->irq_data);
234
235 if (chip->irq_mask)
236 chip->irq_mask(&desc->irq_data);
237
238 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
239 chip->irq_disable(&desc->irq_data);
240 }
241}
242
243/**
244 * machine_crash_shutdown - shutdown non-crashing cpus and save registers
245 */
246void machine_crash_shutdown(struct pt_regs *regs)
247{
248 local_irq_disable();
249
250 /* shutdown non-crashing cpus */
251 crash_smp_send_stop();
252
253 /* for crashing cpu */
254 crash_save_cpu(regs, smp_processor_id());
255 machine_kexec_mask_interrupts();
256
257 pr_info("Starting crashdump kernel...\n");
258}
259
260void arch_kexec_protect_crashkres(void)
261{
262 int i;
263
264 kexec_segment_flush(kexec_crash_image);
265
266 for (i = 0; i < kexec_crash_image->nr_segments; i++)
267 set_memory_valid(
268 __phys_to_virt(kexec_crash_image->segment[i].mem),
269 kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0);
270}
271
272void arch_kexec_unprotect_crashkres(void)
273{
274 int i;
275
276 for (i = 0; i < kexec_crash_image->nr_segments; i++)
277 set_memory_valid(
278 __phys_to_virt(kexec_crash_image->segment[i].mem),
279 kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1);
280}
281
282#ifdef CONFIG_HIBERNATION
283/*
284 * To preserve the crash dump kernel image, the relevant memory segments
285 * should be mapped again around the hibernation.
286 */
287void crash_prepare_suspend(void)
288{
289 if (kexec_crash_image)
290 arch_kexec_unprotect_crashkres();
291}
292
293void crash_post_resume(void)
294{
295 if (kexec_crash_image)
296 arch_kexec_protect_crashkres();
297}
298
299/*
300 * crash_is_nosave
301 *
302 * Return true only if a page is part of reserved memory for crash dump kernel,
303 * but does not hold any data of loaded kernel image.
304 *
305 * Note that all the pages in crash dump kernel memory have been initially
306 * marked as Reserved as memory was allocated via memblock_reserve().
307 *
308 * In hibernation, the pages which are Reserved and yet "nosave" are excluded
309 * from the hibernation iamge. crash_is_nosave() does thich check for crash
310 * dump kernel and will reduce the total size of hibernation image.
311 */
312
313bool crash_is_nosave(unsigned long pfn)
314{
315 int i;
316 phys_addr_t addr;
317
318 if (!crashk_res.end)
319 return false;
320
321 /* in reserved memory? */
322 addr = __pfn_to_phys(pfn);
323 if ((addr < crashk_res.start) || (crashk_res.end < addr))
324 return false;
325
326 if (!kexec_crash_image)
327 return true;
328
329 /* not part of loaded kernel image? */
330 for (i = 0; i < kexec_crash_image->nr_segments; i++)
331 if (addr >= kexec_crash_image->segment[i].mem &&
332 addr < (kexec_crash_image->segment[i].mem +
333 kexec_crash_image->segment[i].memsz))
334 return false;
335
336 return true;
337}
338
339void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
340{
341 unsigned long addr;
342 struct page *page;
343
344 for (addr = begin; addr < end; addr += PAGE_SIZE) {
345 page = phys_to_page(addr);
346 free_reserved_page(page);
347 }
348}
349#endif /* CONFIG_HIBERNATION */