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40b0b3f8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
5033cba0 | 2 | /* |
835c34a1 | 3 | * handle transition of Linux booting another kernel |
5033cba0 | 4 | * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> |
5033cba0 EB |
5 | */ |
6 | ||
7 | #include <linux/mm.h> | |
8 | #include <linux/kexec.h> | |
9 | #include <linux/delay.h> | |
fd59d231 | 10 | #include <linux/numa.h> |
f43fdad8 | 11 | #include <linux/ftrace.h> |
3122c331 | 12 | #include <linux/suspend.h> |
92be3d6b | 13 | #include <linux/gfp.h> |
fef3a7a1 | 14 | #include <linux/io.h> |
f43fdad8 | 15 | |
5033cba0 EB |
16 | #include <asm/pgalloc.h> |
17 | #include <asm/tlbflush.h> | |
18 | #include <asm/mmu_context.h> | |
5033cba0 | 19 | #include <asm/apic.h> |
8643e28d | 20 | #include <asm/io_apic.h> |
5033cba0 | 21 | #include <asm/cpufeature.h> |
e7b47cca | 22 | #include <asm/desc.h> |
d1163651 | 23 | #include <asm/set_memory.h> |
17f557e5 | 24 | #include <asm/debugreg.h> |
5033cba0 | 25 | |
5033cba0 EB |
26 | static void load_segments(void) |
27 | { | |
28 | #define __STR(X) #X | |
29 | #define STR(X) __STR(X) | |
30 | ||
31 | __asm__ __volatile__ ( | |
32 | "\tljmp $"STR(__KERNEL_CS)",$1f\n" | |
33 | "\t1:\n" | |
2ec5e3a8 MM |
34 | "\tmovl $"STR(__KERNEL_DS)",%%eax\n" |
35 | "\tmovl %%eax,%%ds\n" | |
36 | "\tmovl %%eax,%%es\n" | |
2ec5e3a8 | 37 | "\tmovl %%eax,%%ss\n" |
fef3a7a1 | 38 | : : : "eax", "memory"); |
5033cba0 EB |
39 | #undef STR |
40 | #undef __STR | |
41 | } | |
42 | ||
92be3d6b HY |
43 | static void machine_kexec_free_page_tables(struct kimage *image) |
44 | { | |
ca38dc8f | 45 | free_pages((unsigned long)image->arch.pgd, PGD_ALLOCATION_ORDER); |
a466ef76 | 46 | image->arch.pgd = NULL; |
92be3d6b HY |
47 | #ifdef CONFIG_X86_PAE |
48 | free_page((unsigned long)image->arch.pmd0); | |
a466ef76 | 49 | image->arch.pmd0 = NULL; |
92be3d6b | 50 | free_page((unsigned long)image->arch.pmd1); |
a466ef76 | 51 | image->arch.pmd1 = NULL; |
92be3d6b HY |
52 | #endif |
53 | free_page((unsigned long)image->arch.pte0); | |
a466ef76 | 54 | image->arch.pte0 = NULL; |
92be3d6b | 55 | free_page((unsigned long)image->arch.pte1); |
a466ef76 | 56 | image->arch.pte1 = NULL; |
92be3d6b HY |
57 | } |
58 | ||
59 | static int machine_kexec_alloc_page_tables(struct kimage *image) | |
60 | { | |
ca38dc8f JR |
61 | image->arch.pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, |
62 | PGD_ALLOCATION_ORDER); | |
92be3d6b HY |
63 | #ifdef CONFIG_X86_PAE |
64 | image->arch.pmd0 = (pmd_t *)get_zeroed_page(GFP_KERNEL); | |
65 | image->arch.pmd1 = (pmd_t *)get_zeroed_page(GFP_KERNEL); | |
66 | #endif | |
67 | image->arch.pte0 = (pte_t *)get_zeroed_page(GFP_KERNEL); | |
68 | image->arch.pte1 = (pte_t *)get_zeroed_page(GFP_KERNEL); | |
69 | if (!image->arch.pgd || | |
70 | #ifdef CONFIG_X86_PAE | |
71 | !image->arch.pmd0 || !image->arch.pmd1 || | |
72 | #endif | |
73 | !image->arch.pte0 || !image->arch.pte1) { | |
92be3d6b HY |
74 | return -ENOMEM; |
75 | } | |
76 | return 0; | |
77 | } | |
78 | ||
9868ee63 HY |
79 | static void machine_kexec_page_table_set_one( |
80 | pgd_t *pgd, pmd_t *pmd, pte_t *pte, | |
81 | unsigned long vaddr, unsigned long paddr) | |
82 | { | |
7f689041 | 83 | p4d_t *p4d; |
9868ee63 HY |
84 | pud_t *pud; |
85 | ||
86 | pgd += pgd_index(vaddr); | |
87 | #ifdef CONFIG_X86_PAE | |
88 | if (!(pgd_val(*pgd) & _PAGE_PRESENT)) | |
89 | set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT)); | |
90 | #endif | |
7f689041 KS |
91 | p4d = p4d_offset(pgd, vaddr); |
92 | pud = pud_offset(p4d, vaddr); | |
9868ee63 HY |
93 | pmd = pmd_offset(pud, vaddr); |
94 | if (!(pmd_val(*pmd) & _PAGE_PRESENT)) | |
95 | set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE)); | |
96 | pte = pte_offset_kernel(pmd, vaddr); | |
97 | set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC)); | |
98 | } | |
99 | ||
100 | static void machine_kexec_prepare_page_tables(struct kimage *image) | |
101 | { | |
102 | void *control_page; | |
fc6fcdfb | 103 | pmd_t *pmd = NULL; |
9868ee63 HY |
104 | |
105 | control_page = page_address(image->control_code_page); | |
106 | #ifdef CONFIG_X86_PAE | |
107 | pmd = image->arch.pmd0; | |
108 | #endif | |
109 | machine_kexec_page_table_set_one( | |
110 | image->arch.pgd, pmd, image->arch.pte0, | |
111 | (unsigned long)control_page, __pa(control_page)); | |
112 | #ifdef CONFIG_X86_PAE | |
113 | pmd = image->arch.pmd1; | |
114 | #endif | |
115 | machine_kexec_page_table_set_one( | |
116 | image->arch.pgd, pmd, image->arch.pte1, | |
117 | __pa(control_page), __pa(control_page)); | |
118 | } | |
119 | ||
5033cba0 EB |
120 | /* |
121 | * A architecture hook called to validate the | |
122 | * proposed image and prepare the control pages | |
163f6876 | 123 | * as needed. The pages for KEXEC_CONTROL_PAGE_SIZE |
5033cba0 EB |
124 | * have been allocated, but the segments have yet |
125 | * been copied into the kernel. | |
126 | * | |
127 | * Do what every setup is needed on image and the | |
128 | * reboot code buffer to allow us to avoid allocations | |
129 | * later. | |
130 | * | |
92be3d6b HY |
131 | * - Make control page executable. |
132 | * - Allocate page tables | |
9868ee63 | 133 | * - Setup page tables |
5033cba0 EB |
134 | */ |
135 | int machine_kexec_prepare(struct kimage *image) | |
136 | { | |
9868ee63 HY |
137 | int error; |
138 | ||
185be151 | 139 | set_memory_x((unsigned long)page_address(image->control_code_page), 1); |
9868ee63 HY |
140 | error = machine_kexec_alloc_page_tables(image); |
141 | if (error) | |
142 | return error; | |
143 | machine_kexec_prepare_page_tables(image); | |
144 | return 0; | |
5033cba0 EB |
145 | } |
146 | ||
147 | /* | |
148 | * Undo anything leftover by machine_kexec_prepare | |
149 | * when an image is freed. | |
150 | */ | |
151 | void machine_kexec_cleanup(struct kimage *image) | |
152 | { | |
185be151 | 153 | set_memory_nx((unsigned long)page_address(image->control_code_page), 1); |
92be3d6b | 154 | machine_kexec_free_page_tables(image); |
5033cba0 EB |
155 | } |
156 | ||
157 | /* | |
158 | * Do not allocate memory (or fail in any way) in machine_kexec(). | |
159 | * We are past the point of no return, committed to rebooting now. | |
160 | */ | |
3ab83521 | 161 | void machine_kexec(struct kimage *image) |
5033cba0 | 162 | { |
3566561b MD |
163 | unsigned long page_list[PAGES_NR]; |
164 | void *control_page; | |
3122c331 | 165 | int save_ftrace_enabled; |
3ab83521 HY |
166 | asmlinkage unsigned long |
167 | (*relocate_kernel_ptr)(unsigned long indirection_page, | |
168 | unsigned long control_page, | |
169 | unsigned long start_address, | |
170 | unsigned int has_pae, | |
171 | unsigned int preserve_context); | |
5033cba0 | 172 | |
3122c331 | 173 | #ifdef CONFIG_KEXEC_JUMP |
6407df5c | 174 | if (image->preserve_context) |
3122c331 HY |
175 | save_processor_state(); |
176 | #endif | |
177 | ||
178 | save_ftrace_enabled = __ftrace_enabled_save(); | |
f43fdad8 | 179 | |
5033cba0 EB |
180 | /* Interrupts aren't acceptable while we reboot */ |
181 | local_irq_disable(); | |
17f557e5 | 182 | hw_breakpoint_disable(); |
5033cba0 | 183 | |
89081d17 HY |
184 | if (image->preserve_context) { |
185 | #ifdef CONFIG_X86_IO_APIC | |
fef3a7a1 HY |
186 | /* |
187 | * We need to put APICs in legacy mode so that we can | |
89081d17 | 188 | * get timer interrupts in second kernel. kexec/kdump |
50374b96 BH |
189 | * paths already have calls to restore_boot_irq_mode() |
190 | * in one form or other. kexec jump path also need one. | |
89081d17 | 191 | */ |
3c9e76db BH |
192 | clear_IO_APIC(); |
193 | restore_boot_irq_mode(); | |
89081d17 HY |
194 | #endif |
195 | } | |
196 | ||
3566561b | 197 | control_page = page_address(image->control_code_page); |
fb45daa6 | 198 | memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE); |
3566561b | 199 | |
3ab83521 | 200 | relocate_kernel_ptr = control_page; |
3566561b | 201 | page_list[PA_CONTROL_PAGE] = __pa(control_page); |
3ab83521 | 202 | page_list[VA_CONTROL_PAGE] = (unsigned long)control_page; |
92be3d6b | 203 | page_list[PA_PGD] = __pa(image->arch.pgd); |
e7706fc6 KO |
204 | |
205 | if (image->type == KEXEC_TYPE_DEFAULT) | |
206 | page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page) | |
207 | << PAGE_SHIFT); | |
5033cba0 | 208 | |
fef3a7a1 HY |
209 | /* |
210 | * The segment registers are funny things, they have both a | |
2a8a3d5b EB |
211 | * visible and an invisible part. Whenever the visible part is |
212 | * set to a specific selector, the invisible part is loaded | |
213 | * with from a table in memory. At no other time is the | |
214 | * descriptor table in memory accessed. | |
5033cba0 EB |
215 | * |
216 | * I take advantage of this here by force loading the | |
217 | * segments, before I zap the gdt with an invalid value. | |
218 | */ | |
219 | load_segments(); | |
fef3a7a1 HY |
220 | /* |
221 | * The gdt & idt are now invalid. | |
5033cba0 EB |
222 | * If you want to load them you must set up your own idt & gdt. |
223 | */ | |
056c52f5 PAI |
224 | native_idt_invalidate(); |
225 | native_gdt_invalidate(); | |
5033cba0 EB |
226 | |
227 | /* now call it */ | |
3ab83521 HY |
228 | image->start = relocate_kernel_ptr((unsigned long)image->head, |
229 | (unsigned long)page_list, | |
c8128cce DH |
230 | image->start, |
231 | boot_cpu_has(X86_FEATURE_PAE), | |
3ab83521 | 232 | image->preserve_context); |
3122c331 HY |
233 | |
234 | #ifdef CONFIG_KEXEC_JUMP | |
6407df5c | 235 | if (image->preserve_context) |
3122c331 HY |
236 | restore_processor_state(); |
237 | #endif | |
238 | ||
239 | __ftrace_enabled_restore(save_ftrace_enabled); | |
5033cba0 | 240 | } |