4 * Copyright (C) Linaro.
5 * Copyright (C) Huawei Futurewei Technologies.
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.
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>
19 #include <asm/cacheflush.h>
20 #include <asm/cpu_ops.h>
22 #include <asm/mmu_context.h>
25 #include "cpu-reset.h"
27 /* Global variables for the arm64_relocate_new_kernel routine. */
28 extern const unsigned char arm64_relocate_new_kernel[];
29 extern const unsigned long arm64_relocate_new_kernel_size;
32 * kexec_image_info - For debugging output.
34 #define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i)
35 static void _kexec_image_info(const char *func, int line,
36 const struct kimage *kimage)
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);
47 for (i = 0; i < kimage->nr_segments; i++) {
48 pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
50 kimage->segment[i].mem,
51 kimage->segment[i].mem + kimage->segment[i].memsz,
52 kimage->segment[i].memsz,
53 kimage->segment[i].memsz / PAGE_SIZE);
57 void machine_kexec_cleanup(struct kimage *kimage)
59 /* Empty routine needed to avoid build errors. */
63 * machine_kexec_prepare - Prepare for a kexec reboot.
65 * Called from the core kexec code when a kernel image is loaded.
66 * Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus
67 * are stuck in the kernel. This avoids a panic once we hit machine_kexec().
69 int machine_kexec_prepare(struct kimage *kimage)
71 kexec_image_info(kimage);
73 if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
74 pr_err("Can't kexec: CPUs are stuck in the kernel.\n");
82 * kexec_list_flush - Helper to flush the kimage list and source pages to PoC.
84 static void kexec_list_flush(struct kimage *kimage)
86 kimage_entry_t *entry;
88 for (entry = &kimage->head; ; entry++) {
92 /* flush the list entries. */
93 __flush_dcache_area(entry, sizeof(kimage_entry_t));
95 flag = *entry & IND_FLAGS;
99 addr = phys_to_virt(*entry & PAGE_MASK);
102 case IND_INDIRECTION:
103 /* Set entry point just before the new list page. */
104 entry = (kimage_entry_t *)addr - 1;
107 /* flush the source pages. */
108 __flush_dcache_area(addr, PAGE_SIZE);
110 case IND_DESTINATION:
119 * kexec_segment_flush - Helper to flush the kimage segments to PoC.
121 static void kexec_segment_flush(const struct kimage *kimage)
125 pr_debug("%s:\n", __func__);
127 for (i = 0; i < kimage->nr_segments; i++) {
128 pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
130 kimage->segment[i].mem,
131 kimage->segment[i].mem + kimage->segment[i].memsz,
132 kimage->segment[i].memsz,
133 kimage->segment[i].memsz / PAGE_SIZE);
135 __flush_dcache_area(phys_to_virt(kimage->segment[i].mem),
136 kimage->segment[i].memsz);
141 * machine_kexec - Do the kexec reboot.
143 * Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC.
145 void machine_kexec(struct kimage *kimage)
147 phys_addr_t reboot_code_buffer_phys;
148 void *reboot_code_buffer;
149 bool in_kexec_crash = (kimage == kexec_crash_image);
150 bool stuck_cpus = cpus_are_stuck_in_kernel();
153 * New cpus may have become stuck_in_kernel after we loaded the image.
155 BUG_ON(!in_kexec_crash && (stuck_cpus || (num_online_cpus() > 1)));
156 WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()),
157 "Some CPUs may be stale, kdump will be unreliable.\n");
159 reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
160 reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys);
162 kexec_image_info(kimage);
164 pr_debug("%s:%d: control_code_page: %p\n", __func__, __LINE__,
165 kimage->control_code_page);
166 pr_debug("%s:%d: reboot_code_buffer_phys: %pa\n", __func__, __LINE__,
167 &reboot_code_buffer_phys);
168 pr_debug("%s:%d: reboot_code_buffer: %p\n", __func__, __LINE__,
170 pr_debug("%s:%d: relocate_new_kernel: %p\n", __func__, __LINE__,
171 arm64_relocate_new_kernel);
172 pr_debug("%s:%d: relocate_new_kernel_size: 0x%lx(%lu) bytes\n",
173 __func__, __LINE__, arm64_relocate_new_kernel_size,
174 arm64_relocate_new_kernel_size);
177 * Copy arm64_relocate_new_kernel to the reboot_code_buffer for use
178 * after the kernel is shut down.
180 memcpy(reboot_code_buffer, arm64_relocate_new_kernel,
181 arm64_relocate_new_kernel_size);
183 /* Flush the reboot_code_buffer in preparation for its execution. */
184 __flush_dcache_area(reboot_code_buffer, arm64_relocate_new_kernel_size);
185 flush_icache_range((uintptr_t)reboot_code_buffer,
186 arm64_relocate_new_kernel_size);
188 /* Flush the kimage list and its buffers. */
189 kexec_list_flush(kimage);
191 /* Flush the new image if already in place. */
192 if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE))
193 kexec_segment_flush(kimage);
197 /* Disable all DAIF exceptions. */
198 asm volatile ("msr daifset, #0xf" : : : "memory");
201 * cpu_soft_restart will shutdown the MMU, disable data caches, then
202 * transfer control to the reboot_code_buffer which contains a copy of
203 * the arm64_relocate_new_kernel routine. arm64_relocate_new_kernel
204 * uses physical addressing to relocate the new image to its final
205 * position and transfers control to the image entry point when the
206 * relocation is complete.
209 cpu_soft_restart(kimage != kexec_crash_image,
210 reboot_code_buffer_phys, kimage->head, kimage->start, 0);
212 BUG(); /* Should never get here. */
215 static void machine_kexec_mask_interrupts(void)
218 struct irq_desc *desc;
220 for_each_irq_desc(i, desc) {
221 struct irq_chip *chip;
224 chip = irq_desc_get_chip(desc);
229 * First try to remove the active state. If this
230 * fails, try to EOI the interrupt.
232 ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
234 if (ret && irqd_irq_inprogress(&desc->irq_data) &&
236 chip->irq_eoi(&desc->irq_data);
239 chip->irq_mask(&desc->irq_data);
241 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
242 chip->irq_disable(&desc->irq_data);
247 * machine_crash_shutdown - shutdown non-crashing cpus and save registers
249 void machine_crash_shutdown(struct pt_regs *regs)
253 /* shutdown non-crashing cpus */
254 smp_send_crash_stop();
256 /* for crashing cpu */
257 crash_save_cpu(regs, smp_processor_id());
258 machine_kexec_mask_interrupts();
260 pr_info("Starting crashdump kernel...\n");
263 void arch_kexec_protect_crashkres(void)
267 kexec_segment_flush(kexec_crash_image);
269 for (i = 0; i < kexec_crash_image->nr_segments; i++)
271 __phys_to_virt(kexec_crash_image->segment[i].mem),
272 kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0);
275 void arch_kexec_unprotect_crashkres(void)
279 for (i = 0; i < kexec_crash_image->nr_segments; i++)
281 __phys_to_virt(kexec_crash_image->segment[i].mem),
282 kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1);
285 #ifdef CONFIG_HIBERNATION
287 * To preserve the crash dump kernel image, the relevant memory segments
288 * should be mapped again around the hibernation.
290 void crash_prepare_suspend(void)
292 if (kexec_crash_image)
293 arch_kexec_unprotect_crashkres();
296 void crash_post_resume(void)
298 if (kexec_crash_image)
299 arch_kexec_protect_crashkres();
305 * Return true only if a page is part of reserved memory for crash dump kernel,
306 * but does not hold any data of loaded kernel image.
308 * Note that all the pages in crash dump kernel memory have been initially
309 * marked as Reserved in kexec_reserve_crashkres_pages().
311 * In hibernation, the pages which are Reserved and yet "nosave" are excluded
312 * from the hibernation iamge. crash_is_nosave() does thich check for crash
313 * dump kernel and will reduce the total size of hibernation image.
316 bool crash_is_nosave(unsigned long pfn)
324 /* in reserved memory? */
325 addr = __pfn_to_phys(pfn);
326 if ((addr < crashk_res.start) || (crashk_res.end < addr))
329 if (!kexec_crash_image)
332 /* not part of loaded kernel image? */
333 for (i = 0; i < kexec_crash_image->nr_segments; i++)
334 if (addr >= kexec_crash_image->segment[i].mem &&
335 addr < (kexec_crash_image->segment[i].mem +
336 kexec_crash_image->segment[i].memsz))
342 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
347 for (addr = begin; addr < end; addr += PAGE_SIZE) {
348 page = phys_to_page(addr);
349 ClearPageReserved(page);
350 free_reserved_page(page);
353 #endif /* CONFIG_HIBERNATION */