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kexec.h
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1 #ifndef _ASM_X86_KEXEC_H
2 #define _ASM_X86_KEXEC_H
3 
4 #ifdef CONFIG_X86_32
5 # define PA_CONTROL_PAGE 0
6 # define VA_CONTROL_PAGE 1
7 # define PA_PGD 2
8 # define PA_SWAP_PAGE 3
9 # define PAGES_NR 4
10 #else
11 # define PA_CONTROL_PAGE 0
12 # define VA_CONTROL_PAGE 1
13 # define PA_TABLE_PAGE 2
14 # define PA_SWAP_PAGE 3
15 # define PAGES_NR 4
16 #endif
17 
18 # define KEXEC_CONTROL_CODE_MAX_SIZE 2048
19 
20 #ifndef __ASSEMBLY__
21 
22 #include <linux/string.h>
23 
24 #include <asm/page.h>
25 #include <asm/ptrace.h>
26 
27 /*
28  * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
29  * I.e. Maximum page that is mapped directly into kernel memory,
30  * and kmap is not required.
31  *
32  * So far x86_64 is limited to 40 physical address bits.
33  */
34 #ifdef CONFIG_X86_32
35 /* Maximum physical address we can use pages from */
36 # define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
37 /* Maximum address we can reach in physical address mode */
38 # define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
39 /* Maximum address we can use for the control code buffer */
40 # define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
41 
42 # define KEXEC_CONTROL_PAGE_SIZE 4096
43 
44 /* The native architecture */
45 # define KEXEC_ARCH KEXEC_ARCH_386
46 
47 /* We can also handle crash dumps from 64 bit kernel. */
48 # define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
49 #else
50 /* Maximum physical address we can use pages from */
51 # define KEXEC_SOURCE_MEMORY_LIMIT (0xFFFFFFFFFFUL)
52 /* Maximum address we can reach in physical address mode */
53 # define KEXEC_DESTINATION_MEMORY_LIMIT (0xFFFFFFFFFFUL)
54 /* Maximum address we can use for the control pages */
55 # define KEXEC_CONTROL_MEMORY_LIMIT (0xFFFFFFFFFFUL)
56 
57 /* Allocate one page for the pdp and the second for the code */
58 # define KEXEC_CONTROL_PAGE_SIZE (4096UL + 4096UL)
59 
60 /* The native architecture */
61 # define KEXEC_ARCH KEXEC_ARCH_X86_64
62 #endif
63 
64 /*
65  * CPU does not save ss and sp on stack if execution is already
66  * running in kernel mode at the time of NMI occurrence. This code
67  * fixes it.
68  */
69 static inline void crash_fixup_ss_esp(struct pt_regs *newregs,
70  struct pt_regs *oldregs)
71 {
72 #ifdef CONFIG_X86_32
73  newregs->sp = (unsigned long)&(oldregs->sp);
74  asm volatile("xorl %%eax, %%eax\n\t"
75  "movw %%ss, %%ax\n\t"
76  :"=a"(newregs->ss));
77 #endif
78 }
79 
80 /*
81  * This function is responsible for capturing register states if coming
82  * via panic otherwise just fix up the ss and sp if coming via kernel
83  * mode exception.
84  */
85 static inline void crash_setup_regs(struct pt_regs *newregs,
86  struct pt_regs *oldregs)
87 {
88  if (oldregs) {
89  memcpy(newregs, oldregs, sizeof(*newregs));
90  crash_fixup_ss_esp(newregs, oldregs);
91  } else {
92 #ifdef CONFIG_X86_32
93  asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
94  asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
95  asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
96  asm volatile("movl %%esi,%0" : "=m"(newregs->si));
97  asm volatile("movl %%edi,%0" : "=m"(newregs->di));
98  asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
99  asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
100  asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
101  asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
102  asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
103  asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
104  asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
105  asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
106 #else
107  asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
108  asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
109  asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
110  asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
111  asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
112  asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
113  asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
114  asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
115  asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
116  asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
117  asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
118  asm volatile("movq %%r11,%0" : "=m"(newregs->r11));
119  asm volatile("movq %%r12,%0" : "=m"(newregs->r12));
120  asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
121  asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
122  asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
123  asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
124  asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
125  asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
126 #endif
127  newregs->ip = (unsigned long)current_text_addr();
128  }
129 }
130 
131 #ifdef CONFIG_X86_32
132 asmlinkage unsigned long
133 relocate_kernel(unsigned long indirection_page,
134  unsigned long control_page,
135  unsigned long start_address,
136  unsigned int has_pae,
137  unsigned int preserve_context);
138 #else
139 unsigned long
140 relocate_kernel(unsigned long indirection_page,
141  unsigned long page_list,
142  unsigned long start_address,
143  unsigned int preserve_context);
144 #endif
145 
146 #define ARCH_HAS_KIMAGE_ARCH
147 
148 #ifdef CONFIG_X86_32
149 struct kimage_arch {
150  pgd_t *pgd;
151 #ifdef CONFIG_X86_PAE
152  pmd_t *pmd0;
153  pmd_t *pmd1;
154 #endif
155  pte_t *pte0;
156  pte_t *pte1;
157 };
158 #else
159 struct kimage_arch {
163 };
164 #endif
165 
166 #endif /* __ASSEMBLY__ */
167 
168 #endif /* _ASM_X86_KEXEC_H */