Commit | Line | Data |
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d28f6df1 GL |
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/kexec.h> | |
13 | #include <linux/smp.h> | |
14 | ||
15 | #include <asm/cacheflush.h> | |
16 | #include <asm/cpu_ops.h> | |
17 | #include <asm/mmu_context.h> | |
18 | ||
19 | #include "cpu-reset.h" | |
20 | ||
21 | /* Global variables for the arm64_relocate_new_kernel routine. */ | |
22 | extern const unsigned char arm64_relocate_new_kernel[]; | |
23 | extern const unsigned long arm64_relocate_new_kernel_size; | |
24 | ||
25 | static unsigned long kimage_start; | |
26 | ||
221f2c77 GL |
27 | /** |
28 | * kexec_image_info - For debugging output. | |
29 | */ | |
30 | #define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i) | |
31 | static void _kexec_image_info(const char *func, int line, | |
32 | const struct kimage *kimage) | |
33 | { | |
34 | unsigned long i; | |
35 | ||
36 | pr_debug("%s:%d:\n", func, line); | |
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 | kimage->segment[i].memsz, | |
49 | kimage->segment[i].memsz / PAGE_SIZE); | |
50 | } | |
51 | } | |
52 | ||
d28f6df1 GL |
53 | void machine_kexec_cleanup(struct kimage *kimage) |
54 | { | |
55 | /* Empty routine needed to avoid build errors. */ | |
56 | } | |
57 | ||
58 | /** | |
59 | * machine_kexec_prepare - Prepare for a kexec reboot. | |
60 | * | |
61 | * Called from the core kexec code when a kernel image is loaded. | |
62 | * Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus | |
63 | * are stuck in the kernel. This avoids a panic once we hit machine_kexec(). | |
64 | */ | |
65 | int machine_kexec_prepare(struct kimage *kimage) | |
66 | { | |
67 | kimage_start = kimage->start; | |
68 | ||
221f2c77 GL |
69 | kexec_image_info(kimage); |
70 | ||
d28f6df1 GL |
71 | if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) { |
72 | pr_err("Can't kexec: CPUs are stuck in the kernel.\n"); | |
73 | return -EBUSY; | |
74 | } | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | /** | |
80 | * kexec_list_flush - Helper to flush the kimage list and source pages to PoC. | |
81 | */ | |
82 | static void kexec_list_flush(struct kimage *kimage) | |
83 | { | |
84 | kimage_entry_t *entry; | |
85 | ||
86 | for (entry = &kimage->head; ; entry++) { | |
87 | unsigned int flag; | |
88 | void *addr; | |
89 | ||
90 | /* flush the list entries. */ | |
91 | __flush_dcache_area(entry, sizeof(kimage_entry_t)); | |
92 | ||
93 | flag = *entry & IND_FLAGS; | |
94 | if (flag == IND_DONE) | |
95 | break; | |
96 | ||
97 | addr = phys_to_virt(*entry & PAGE_MASK); | |
98 | ||
99 | switch (flag) { | |
100 | case IND_INDIRECTION: | |
101 | /* Set entry point just before the new list page. */ | |
102 | entry = (kimage_entry_t *)addr - 1; | |
103 | break; | |
104 | case IND_SOURCE: | |
105 | /* flush the source pages. */ | |
106 | __flush_dcache_area(addr, PAGE_SIZE); | |
107 | break; | |
108 | case IND_DESTINATION: | |
109 | break; | |
110 | default: | |
111 | BUG(); | |
112 | } | |
113 | } | |
114 | } | |
115 | ||
116 | /** | |
117 | * kexec_segment_flush - Helper to flush the kimage segments to PoC. | |
118 | */ | |
119 | static void kexec_segment_flush(const struct kimage *kimage) | |
120 | { | |
121 | unsigned long i; | |
122 | ||
123 | pr_debug("%s:\n", __func__); | |
124 | ||
125 | for (i = 0; i < kimage->nr_segments; i++) { | |
126 | pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n", | |
127 | i, | |
128 | kimage->segment[i].mem, | |
129 | kimage->segment[i].mem + kimage->segment[i].memsz, | |
130 | kimage->segment[i].memsz, | |
131 | kimage->segment[i].memsz / PAGE_SIZE); | |
132 | ||
133 | __flush_dcache_area(phys_to_virt(kimage->segment[i].mem), | |
134 | kimage->segment[i].memsz); | |
135 | } | |
136 | } | |
137 | ||
138 | /** | |
139 | * machine_kexec - Do the kexec reboot. | |
140 | * | |
141 | * Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC. | |
142 | */ | |
143 | void machine_kexec(struct kimage *kimage) | |
144 | { | |
145 | phys_addr_t reboot_code_buffer_phys; | |
146 | void *reboot_code_buffer; | |
147 | ||
148 | /* | |
149 | * New cpus may have become stuck_in_kernel after we loaded the image. | |
150 | */ | |
151 | BUG_ON(cpus_are_stuck_in_kernel() || (num_online_cpus() > 1)); | |
152 | ||
153 | reboot_code_buffer_phys = page_to_phys(kimage->control_code_page); | |
154 | reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys); | |
155 | ||
221f2c77 GL |
156 | kexec_image_info(kimage); |
157 | ||
158 | pr_debug("%s:%d: control_code_page: %p\n", __func__, __LINE__, | |
159 | kimage->control_code_page); | |
160 | pr_debug("%s:%d: reboot_code_buffer_phys: %pa\n", __func__, __LINE__, | |
161 | &reboot_code_buffer_phys); | |
162 | pr_debug("%s:%d: reboot_code_buffer: %p\n", __func__, __LINE__, | |
163 | reboot_code_buffer); | |
164 | pr_debug("%s:%d: relocate_new_kernel: %p\n", __func__, __LINE__, | |
165 | arm64_relocate_new_kernel); | |
166 | pr_debug("%s:%d: relocate_new_kernel_size: 0x%lx(%lu) bytes\n", | |
167 | __func__, __LINE__, arm64_relocate_new_kernel_size, | |
168 | arm64_relocate_new_kernel_size); | |
169 | ||
d28f6df1 GL |
170 | /* |
171 | * Copy arm64_relocate_new_kernel to the reboot_code_buffer for use | |
172 | * after the kernel is shut down. | |
173 | */ | |
174 | memcpy(reboot_code_buffer, arm64_relocate_new_kernel, | |
175 | arm64_relocate_new_kernel_size); | |
176 | ||
177 | /* Flush the reboot_code_buffer in preparation for its execution. */ | |
178 | __flush_dcache_area(reboot_code_buffer, arm64_relocate_new_kernel_size); | |
179 | flush_icache_range((uintptr_t)reboot_code_buffer, | |
180 | arm64_relocate_new_kernel_size); | |
181 | ||
182 | /* Flush the kimage list and its buffers. */ | |
183 | kexec_list_flush(kimage); | |
184 | ||
185 | /* Flush the new image if already in place. */ | |
186 | if (kimage->head & IND_DONE) | |
187 | kexec_segment_flush(kimage); | |
188 | ||
189 | pr_info("Bye!\n"); | |
190 | ||
191 | /* Disable all DAIF exceptions. */ | |
192 | asm volatile ("msr daifset, #0xf" : : : "memory"); | |
193 | ||
194 | /* | |
195 | * cpu_soft_restart will shutdown the MMU, disable data caches, then | |
196 | * transfer control to the reboot_code_buffer 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 | */ | |
202 | ||
203 | cpu_soft_restart(1, reboot_code_buffer_phys, kimage->head, | |
204 | kimage_start, 0); | |
205 | ||
206 | BUG(); /* Should never get here. */ | |
207 | } | |
208 | ||
209 | void machine_crash_shutdown(struct pt_regs *regs) | |
210 | { | |
211 | /* Empty routine needed to avoid build errors. */ | |
212 | } |