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7#include <linux/mm.h>
8#include <linux/kexec.h>
9#include <linux/delay.h>
10#include <linux/numa.h>
11#include <linux/ftrace.h>
12#include <linux/suspend.h>
13#include <linux/gfp.h>
14#include <linux/io.h>
15
16#include <asm/pgalloc.h>
17#include <asm/tlbflush.h>
18#include <asm/mmu_context.h>
19#include <asm/apic.h>
20#include <asm/io_apic.h>
21#include <asm/cpufeature.h>
22#include <asm/desc.h>
23#include <asm/set_memory.h>
24#include <asm/debugreg.h>
25
26static void set_gdt(void *newgdt, __u16 limit)
27{
28 struct desc_ptr curgdt;
29
30
31 curgdt.size = limit;
32 curgdt.address = (unsigned long)newgdt;
33
34 load_gdt(&curgdt);
35}
36
37static void load_segments(void)
38{
39#define __STR(X) #X
40#define STR(X) __STR(X)
41
42 __asm__ __volatile__ (
43 "\tljmp $"STR(__KERNEL_CS)",$1f\n"
44 "\t1:\n"
45 "\tmovl $"STR(__KERNEL_DS)",%%eax\n"
46 "\tmovl %%eax,%%ds\n"
47 "\tmovl %%eax,%%es\n"
48 "\tmovl %%eax,%%ss\n"
49 : : : "eax", "memory");
50#undef STR
51#undef __STR
52}
53
54static void machine_kexec_free_page_tables(struct kimage *image)
55{
56 free_pages((unsigned long)image->arch.pgd, PGD_ALLOCATION_ORDER);
57 image->arch.pgd = NULL;
58#ifdef CONFIG_X86_PAE
59 free_page((unsigned long)image->arch.pmd0);
60 image->arch.pmd0 = NULL;
61 free_page((unsigned long)image->arch.pmd1);
62 image->arch.pmd1 = NULL;
63#endif
64 free_page((unsigned long)image->arch.pte0);
65 image->arch.pte0 = NULL;
66 free_page((unsigned long)image->arch.pte1);
67 image->arch.pte1 = NULL;
68}
69
70static int machine_kexec_alloc_page_tables(struct kimage *image)
71{
72 image->arch.pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
73 PGD_ALLOCATION_ORDER);
74#ifdef CONFIG_X86_PAE
75 image->arch.pmd0 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
76 image->arch.pmd1 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
77#endif
78 image->arch.pte0 = (pte_t *)get_zeroed_page(GFP_KERNEL);
79 image->arch.pte1 = (pte_t *)get_zeroed_page(GFP_KERNEL);
80 if (!image->arch.pgd ||
81#ifdef CONFIG_X86_PAE
82 !image->arch.pmd0 || !image->arch.pmd1 ||
83#endif
84 !image->arch.pte0 || !image->arch.pte1) {
85 return -ENOMEM;
86 }
87 return 0;
88}
89
90static void machine_kexec_page_table_set_one(
91 pgd_t *pgd, pmd_t *pmd, pte_t *pte,
92 unsigned long vaddr, unsigned long paddr)
93{
94 p4d_t *p4d;
95 pud_t *pud;
96
97 pgd += pgd_index(vaddr);
98#ifdef CONFIG_X86_PAE
99 if (!(pgd_val(*pgd) & _PAGE_PRESENT))
100 set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT));
101#endif
102 p4d = p4d_offset(pgd, vaddr);
103 pud = pud_offset(p4d, vaddr);
104 pmd = pmd_offset(pud, vaddr);
105 if (!(pmd_val(*pmd) & _PAGE_PRESENT))
106 set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
107 pte = pte_offset_kernel(pmd, vaddr);
108 set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
109}
110
111static void machine_kexec_prepare_page_tables(struct kimage *image)
112{
113 void *control_page;
114 pmd_t *pmd = NULL;
115
116 control_page = page_address(image->control_code_page);
117#ifdef CONFIG_X86_PAE
118 pmd = image->arch.pmd0;
119#endif
120 machine_kexec_page_table_set_one(
121 image->arch.pgd, pmd, image->arch.pte0,
122 (unsigned long)control_page, __pa(control_page));
123#ifdef CONFIG_X86_PAE
124 pmd = image->arch.pmd1;
125#endif
126 machine_kexec_page_table_set_one(
127 image->arch.pgd, pmd, image->arch.pte1,
128 __pa(control_page), __pa(control_page));
129}
130
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144
145
146int machine_kexec_prepare(struct kimage *image)
147{
148 int error;
149
150 set_memory_x((unsigned long)page_address(image->control_code_page), 1);
151 error = machine_kexec_alloc_page_tables(image);
152 if (error)
153 return error;
154 machine_kexec_prepare_page_tables(image);
155 return 0;
156}
157
158
159
160
161
162void machine_kexec_cleanup(struct kimage *image)
163{
164 set_memory_nx((unsigned long)page_address(image->control_code_page), 1);
165 machine_kexec_free_page_tables(image);
166}
167
168
169
170
171
172void machine_kexec(struct kimage *image)
173{
174 unsigned long page_list[PAGES_NR];
175 void *control_page;
176 int save_ftrace_enabled;
177 asmlinkage unsigned long
178 (*relocate_kernel_ptr)(unsigned long indirection_page,
179 unsigned long control_page,
180 unsigned long start_address,
181 unsigned int has_pae,
182 unsigned int preserve_context);
183
184#ifdef CONFIG_KEXEC_JUMP
185 if (image->preserve_context)
186 save_processor_state();
187#endif
188
189 save_ftrace_enabled = __ftrace_enabled_save();
190
191
192 local_irq_disable();
193 hw_breakpoint_disable();
194
195 if (image->preserve_context) {
196#ifdef CONFIG_X86_IO_APIC
197
198
199
200
201
202
203 clear_IO_APIC();
204 restore_boot_irq_mode();
205#endif
206 }
207
208 control_page = page_address(image->control_code_page);
209 memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
210
211 relocate_kernel_ptr = control_page;
212 page_list[PA_CONTROL_PAGE] = __pa(control_page);
213 page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
214 page_list[PA_PGD] = __pa(image->arch.pgd);
215
216 if (image->type == KEXEC_TYPE_DEFAULT)
217 page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
218 << PAGE_SHIFT);
219
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229
230 load_segments();
231
232
233
234
235 idt_invalidate(phys_to_virt(0));
236 set_gdt(phys_to_virt(0), 0);
237
238
239 image->start = relocate_kernel_ptr((unsigned long)image->head,
240 (unsigned long)page_list,
241 image->start,
242 boot_cpu_has(X86_FEATURE_PAE),
243 image->preserve_context);
244
245#ifdef CONFIG_KEXEC_JUMP
246 if (image->preserve_context)
247 restore_processor_state();
248#endif
249
250 __ftrace_enabled_restore(save_ftrace_enabled);
251}
252