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Commit | Line | Data |
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5234f5eb | 1 | /* |
835c34a1 | 2 | * handle transition of Linux booting another kernel |
5234f5eb EB |
3 | * Copyright (C) 2002-2005 Eric Biederman <[email protected]> |
4 | * | |
5 | * This source code is licensed under the GNU General Public License, | |
6 | * Version 2. See the file COPYING for more details. | |
7 | */ | |
8 | ||
9 | #include <linux/mm.h> | |
10 | #include <linux/kexec.h> | |
5234f5eb | 11 | #include <linux/string.h> |
5a0e3ad6 | 12 | #include <linux/gfp.h> |
5234f5eb | 13 | #include <linux/reboot.h> |
fd59d231 | 14 | #include <linux/numa.h> |
f43fdad8 | 15 | #include <linux/ftrace.h> |
fef3a7a1 | 16 | #include <linux/io.h> |
fee7b0d8 | 17 | #include <linux/suspend.h> |
f43fdad8 | 18 | |
5234f5eb | 19 | #include <asm/pgtable.h> |
5234f5eb EB |
20 | #include <asm/tlbflush.h> |
21 | #include <asm/mmu_context.h> | |
17f557e5 | 22 | #include <asm/debugreg.h> |
8bf27556 | 23 | |
53594547 YH |
24 | static int init_one_level2_page(struct kimage *image, pgd_t *pgd, |
25 | unsigned long addr) | |
26 | { | |
27 | pud_t *pud; | |
28 | pmd_t *pmd; | |
29 | struct page *page; | |
30 | int result = -ENOMEM; | |
31 | ||
32 | addr &= PMD_MASK; | |
33 | pgd += pgd_index(addr); | |
34 | if (!pgd_present(*pgd)) { | |
35 | page = kimage_alloc_control_pages(image, 0); | |
36 | if (!page) | |
37 | goto out; | |
38 | pud = (pud_t *)page_address(page); | |
234bb549 | 39 | clear_page(pud); |
53594547 YH |
40 | set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); |
41 | } | |
42 | pud = pud_offset(pgd, addr); | |
43 | if (!pud_present(*pud)) { | |
44 | page = kimage_alloc_control_pages(image, 0); | |
45 | if (!page) | |
46 | goto out; | |
47 | pmd = (pmd_t *)page_address(page); | |
234bb549 | 48 | clear_page(pmd); |
53594547 YH |
49 | set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); |
50 | } | |
51 | pmd = pmd_offset(pud, addr); | |
52 | if (!pmd_present(*pmd)) | |
53 | set_pmd(pmd, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC)); | |
54 | result = 0; | |
55 | out: | |
56 | return result; | |
57 | } | |
58 | ||
8bf27556 | 59 | static void init_level2_page(pmd_t *level2p, unsigned long addr) |
5234f5eb EB |
60 | { |
61 | unsigned long end_addr; | |
72414d3f | 62 | |
5234f5eb | 63 | addr &= PAGE_MASK; |
8bf27556 | 64 | end_addr = addr + PUD_SIZE; |
72414d3f | 65 | while (addr < end_addr) { |
8bf27556 EB |
66 | set_pmd(level2p++, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC)); |
67 | addr += PMD_SIZE; | |
5234f5eb EB |
68 | } |
69 | } | |
70 | ||
8bf27556 | 71 | static int init_level3_page(struct kimage *image, pud_t *level3p, |
72414d3f | 72 | unsigned long addr, unsigned long last_addr) |
5234f5eb EB |
73 | { |
74 | unsigned long end_addr; | |
75 | int result; | |
72414d3f | 76 | |
5234f5eb EB |
77 | result = 0; |
78 | addr &= PAGE_MASK; | |
8bf27556 | 79 | end_addr = addr + PGDIR_SIZE; |
72414d3f | 80 | while ((addr < last_addr) && (addr < end_addr)) { |
5234f5eb | 81 | struct page *page; |
8bf27556 | 82 | pmd_t *level2p; |
72414d3f | 83 | |
5234f5eb EB |
84 | page = kimage_alloc_control_pages(image, 0); |
85 | if (!page) { | |
86 | result = -ENOMEM; | |
87 | goto out; | |
88 | } | |
8bf27556 | 89 | level2p = (pmd_t *)page_address(page); |
5234f5eb | 90 | init_level2_page(level2p, addr); |
8bf27556 EB |
91 | set_pud(level3p++, __pud(__pa(level2p) | _KERNPG_TABLE)); |
92 | addr += PUD_SIZE; | |
5234f5eb EB |
93 | } |
94 | /* clear the unused entries */ | |
72414d3f | 95 | while (addr < end_addr) { |
8bf27556 EB |
96 | pud_clear(level3p++); |
97 | addr += PUD_SIZE; | |
5234f5eb EB |
98 | } |
99 | out: | |
100 | return result; | |
101 | } | |
102 | ||
103 | ||
8bf27556 | 104 | static int init_level4_page(struct kimage *image, pgd_t *level4p, |
72414d3f | 105 | unsigned long addr, unsigned long last_addr) |
5234f5eb EB |
106 | { |
107 | unsigned long end_addr; | |
108 | int result; | |
72414d3f | 109 | |
5234f5eb EB |
110 | result = 0; |
111 | addr &= PAGE_MASK; | |
8bf27556 | 112 | end_addr = addr + (PTRS_PER_PGD * PGDIR_SIZE); |
72414d3f | 113 | while ((addr < last_addr) && (addr < end_addr)) { |
5234f5eb | 114 | struct page *page; |
8bf27556 | 115 | pud_t *level3p; |
72414d3f | 116 | |
5234f5eb EB |
117 | page = kimage_alloc_control_pages(image, 0); |
118 | if (!page) { | |
119 | result = -ENOMEM; | |
120 | goto out; | |
121 | } | |
8bf27556 | 122 | level3p = (pud_t *)page_address(page); |
5234f5eb | 123 | result = init_level3_page(image, level3p, addr, last_addr); |
fef3a7a1 | 124 | if (result) |
5234f5eb | 125 | goto out; |
8bf27556 EB |
126 | set_pgd(level4p++, __pgd(__pa(level3p) | _KERNPG_TABLE)); |
127 | addr += PGDIR_SIZE; | |
5234f5eb EB |
128 | } |
129 | /* clear the unused entries */ | |
72414d3f | 130 | while (addr < end_addr) { |
8bf27556 EB |
131 | pgd_clear(level4p++); |
132 | addr += PGDIR_SIZE; | |
5234f5eb | 133 | } |
72414d3f | 134 | out: |
5234f5eb EB |
135 | return result; |
136 | } | |
137 | ||
f5deb796 YH |
138 | static void free_transition_pgtable(struct kimage *image) |
139 | { | |
140 | free_page((unsigned long)image->arch.pud); | |
141 | free_page((unsigned long)image->arch.pmd); | |
142 | free_page((unsigned long)image->arch.pte); | |
143 | } | |
144 | ||
145 | static int init_transition_pgtable(struct kimage *image, pgd_t *pgd) | |
146 | { | |
147 | pud_t *pud; | |
148 | pmd_t *pmd; | |
149 | pte_t *pte; | |
150 | unsigned long vaddr, paddr; | |
151 | int result = -ENOMEM; | |
152 | ||
153 | vaddr = (unsigned long)relocate_kernel; | |
154 | paddr = __pa(page_address(image->control_code_page)+PAGE_SIZE); | |
155 | pgd += pgd_index(vaddr); | |
156 | if (!pgd_present(*pgd)) { | |
157 | pud = (pud_t *)get_zeroed_page(GFP_KERNEL); | |
158 | if (!pud) | |
159 | goto err; | |
160 | image->arch.pud = pud; | |
161 | set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); | |
162 | } | |
163 | pud = pud_offset(pgd, vaddr); | |
164 | if (!pud_present(*pud)) { | |
165 | pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL); | |
166 | if (!pmd) | |
167 | goto err; | |
168 | image->arch.pmd = pmd; | |
169 | set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); | |
170 | } | |
171 | pmd = pmd_offset(pud, vaddr); | |
172 | if (!pmd_present(*pmd)) { | |
173 | pte = (pte_t *)get_zeroed_page(GFP_KERNEL); | |
174 | if (!pte) | |
175 | goto err; | |
176 | image->arch.pte = pte; | |
177 | set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE)); | |
178 | } | |
179 | pte = pte_offset_kernel(pmd, vaddr); | |
180 | set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC)); | |
181 | return 0; | |
182 | err: | |
183 | free_transition_pgtable(image); | |
184 | return result; | |
185 | } | |
186 | ||
5234f5eb EB |
187 | |
188 | static int init_pgtable(struct kimage *image, unsigned long start_pgtable) | |
189 | { | |
8bf27556 | 190 | pgd_t *level4p; |
f5deb796 | 191 | int result; |
8bf27556 | 192 | level4p = (pgd_t *)__va(start_pgtable); |
f5deb796 | 193 | result = init_level4_page(image, level4p, 0, max_pfn << PAGE_SHIFT); |
53594547 YH |
194 | if (result) |
195 | return result; | |
196 | /* | |
197 | * image->start may be outside 0 ~ max_pfn, for example when | |
198 | * jump back to original kernel from kexeced kernel | |
199 | */ | |
200 | result = init_one_level2_page(image, level4p, image->start); | |
f5deb796 YH |
201 | if (result) |
202 | return result; | |
203 | return init_transition_pgtable(image, level4p); | |
5234f5eb EB |
204 | } |
205 | ||
206 | static void set_idt(void *newidt, u16 limit) | |
207 | { | |
36c4fd23 | 208 | struct desc_ptr curidt; |
5234f5eb EB |
209 | |
210 | /* x86-64 supports unaliged loads & stores */ | |
36c4fd23 EB |
211 | curidt.size = limit; |
212 | curidt.address = (unsigned long)newidt; | |
5234f5eb EB |
213 | |
214 | __asm__ __volatile__ ( | |
36c4fd23 EB |
215 | "lidtq %0\n" |
216 | : : "m" (curidt) | |
5234f5eb EB |
217 | ); |
218 | }; | |
219 | ||
220 | ||
221 | static void set_gdt(void *newgdt, u16 limit) | |
222 | { | |
36c4fd23 | 223 | struct desc_ptr curgdt; |
5234f5eb EB |
224 | |
225 | /* x86-64 supports unaligned loads & stores */ | |
36c4fd23 EB |
226 | curgdt.size = limit; |
227 | curgdt.address = (unsigned long)newgdt; | |
5234f5eb EB |
228 | |
229 | __asm__ __volatile__ ( | |
36c4fd23 EB |
230 | "lgdtq %0\n" |
231 | : : "m" (curgdt) | |
5234f5eb EB |
232 | ); |
233 | }; | |
234 | ||
235 | static void load_segments(void) | |
236 | { | |
237 | __asm__ __volatile__ ( | |
36c4fd23 EB |
238 | "\tmovl %0,%%ds\n" |
239 | "\tmovl %0,%%es\n" | |
240 | "\tmovl %0,%%ss\n" | |
241 | "\tmovl %0,%%fs\n" | |
242 | "\tmovl %0,%%gs\n" | |
2ec5e3a8 | 243 | : : "a" (__KERNEL_DS) : "memory" |
5234f5eb | 244 | ); |
5234f5eb EB |
245 | } |
246 | ||
5234f5eb EB |
247 | int machine_kexec_prepare(struct kimage *image) |
248 | { | |
4bfaaef0 | 249 | unsigned long start_pgtable; |
5234f5eb EB |
250 | int result; |
251 | ||
252 | /* Calculate the offsets */ | |
72414d3f | 253 | start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT; |
5234f5eb EB |
254 | |
255 | /* Setup the identity mapped 64bit page table */ | |
256 | result = init_pgtable(image, start_pgtable); | |
72414d3f | 257 | if (result) |
5234f5eb | 258 | return result; |
5234f5eb | 259 | |
5234f5eb EB |
260 | return 0; |
261 | } | |
262 | ||
263 | void machine_kexec_cleanup(struct kimage *image) | |
264 | { | |
f5deb796 | 265 | free_transition_pgtable(image); |
5234f5eb EB |
266 | } |
267 | ||
268 | /* | |
269 | * Do not allocate memory (or fail in any way) in machine_kexec(). | |
270 | * We are past the point of no return, committed to rebooting now. | |
271 | */ | |
3ab83521 | 272 | void machine_kexec(struct kimage *image) |
5234f5eb | 273 | { |
4bfaaef0 MD |
274 | unsigned long page_list[PAGES_NR]; |
275 | void *control_page; | |
fee7b0d8 | 276 | int save_ftrace_enabled; |
5234f5eb | 277 | |
fee7b0d8 | 278 | #ifdef CONFIG_KEXEC_JUMP |
6407df5c | 279 | if (image->preserve_context) |
fee7b0d8 YH |
280 | save_processor_state(); |
281 | #endif | |
282 | ||
283 | save_ftrace_enabled = __ftrace_enabled_save(); | |
f43fdad8 | 284 | |
5234f5eb EB |
285 | /* Interrupts aren't acceptable while we reboot */ |
286 | local_irq_disable(); | |
17f557e5 | 287 | hw_breakpoint_disable(); |
5234f5eb | 288 | |
fee7b0d8 YH |
289 | if (image->preserve_context) { |
290 | #ifdef CONFIG_X86_IO_APIC | |
291 | /* | |
292 | * We need to put APICs in legacy mode so that we can | |
293 | * get timer interrupts in second kernel. kexec/kdump | |
294 | * paths already have calls to disable_IO_APIC() in | |
295 | * one form or other. kexec jump path also need | |
296 | * one. | |
297 | */ | |
298 | disable_IO_APIC(); | |
299 | #endif | |
300 | } | |
301 | ||
4bfaaef0 | 302 | control_page = page_address(image->control_code_page) + PAGE_SIZE; |
fee7b0d8 | 303 | memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE); |
4bfaaef0 | 304 | |
e3ebadd9 | 305 | page_list[PA_CONTROL_PAGE] = virt_to_phys(control_page); |
fee7b0d8 | 306 | page_list[VA_CONTROL_PAGE] = (unsigned long)control_page; |
4bfaaef0 MD |
307 | page_list[PA_TABLE_PAGE] = |
308 | (unsigned long)__pa(page_address(image->control_code_page)); | |
5234f5eb | 309 | |
fee7b0d8 YH |
310 | if (image->type == KEXEC_TYPE_DEFAULT) |
311 | page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page) | |
312 | << PAGE_SHIFT); | |
313 | ||
fef3a7a1 YH |
314 | /* |
315 | * The segment registers are funny things, they have both a | |
2a8a3d5b EB |
316 | * visible and an invisible part. Whenever the visible part is |
317 | * set to a specific selector, the invisible part is loaded | |
318 | * with from a table in memory. At no other time is the | |
319 | * descriptor table in memory accessed. | |
5234f5eb EB |
320 | * |
321 | * I take advantage of this here by force loading the | |
322 | * segments, before I zap the gdt with an invalid value. | |
323 | */ | |
324 | load_segments(); | |
fef3a7a1 YH |
325 | /* |
326 | * The gdt & idt are now invalid. | |
5234f5eb EB |
327 | * If you want to load them you must set up your own idt & gdt. |
328 | */ | |
fef3a7a1 YH |
329 | set_gdt(phys_to_virt(0), 0); |
330 | set_idt(phys_to_virt(0), 0); | |
4bfaaef0 | 331 | |
5234f5eb | 332 | /* now call it */ |
fee7b0d8 YH |
333 | image->start = relocate_kernel((unsigned long)image->head, |
334 | (unsigned long)page_list, | |
335 | image->start, | |
336 | image->preserve_context); | |
337 | ||
338 | #ifdef CONFIG_KEXEC_JUMP | |
6407df5c | 339 | if (image->preserve_context) |
fee7b0d8 YH |
340 | restore_processor_state(); |
341 | #endif | |
342 | ||
343 | __ftrace_enabled_restore(save_ftrace_enabled); | |
5234f5eb | 344 | } |
2c8c0e6b | 345 | |
fd59d231 KO |
346 | void arch_crash_save_vmcoreinfo(void) |
347 | { | |
629c8b4c | 348 | VMCOREINFO_SYMBOL(phys_base); |
69243f91 | 349 | VMCOREINFO_SYMBOL(init_level4_pgt); |
92df5c3e KO |
350 | |
351 | #ifdef CONFIG_NUMA | |
352 | VMCOREINFO_SYMBOL(node_data); | |
353 | VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); | |
354 | #endif | |
fd59d231 KO |
355 | } |
356 |