aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/kexec.h
blob: 17483a492f1882f218849bedd1c26d8a970d433f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
#ifndef _ASM_X86_KEXEC_H
#define _ASM_X86_KEXEC_H

#ifdef CONFIG_X86_32
# define PA_CONTROL_PAGE	0
# define VA_CONTROL_PAGE	1
# define PA_PGD			2
# define PA_SWAP_PAGE		3
# define PAGES_NR		4
#else
# define PA_CONTROL_PAGE	0
# define VA_CONTROL_PAGE	1
# define PA_TABLE_PAGE		2
# define PA_SWAP_PAGE		3
# define PAGES_NR		4
#endif

# define KEXEC_CONTROL_CODE_MAX_SIZE	2048

#ifndef __ASSEMBLY__

#include <linux/string.h>

#include <asm/page.h>
#include <asm/ptrace.h>

/*
 * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
 * I.e. Maximum page that is mapped directly into kernel memory,
 * and kmap is not required.
 *
 * So far x86_64 is limited to 40 physical address bits.
 */
#ifdef CONFIG_X86_32
/* Maximum physical address we can use pages from */
# define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
/* Maximum address we can reach in physical address mode */
# define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
/* Maximum address we can use for the control code buffer */
# define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE

# define KEXEC_CONTROL_PAGE_SIZE	4096

/* The native architecture */
# define KEXEC_ARCH KEXEC_ARCH_386

/* We can also handle crash dumps from 64 bit kernel. */
# define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
#else
/* Maximum physical address we can use pages from */
# define KEXEC_SOURCE_MEMORY_LIMIT      (MAXMEM-1)
/* Maximum address we can reach in physical address mode */
# define KEXEC_DESTINATION_MEMORY_LIMIT (MAXMEM-1)
/* Maximum address we can use for the control pages */
# define KEXEC_CONTROL_MEMORY_LIMIT     (MAXMEM-1)

/* Allocate one page for the pdp and the second for the code */
# define KEXEC_CONTROL_PAGE_SIZE  (4096UL + 4096UL)

/* The native architecture */
# define KEXEC_ARCH KEXEC_ARCH_X86_64
#endif

/*
 * CPU does not save ss and sp on stack if execution is already
 * running in kernel mode at the time of NMI occurrence. This code
 * fixes it.
 */
static inline void crash_fixup_ss_esp(struct pt_regs *newregs,
				      struct pt_regs *oldregs)
{
#ifdef CONFIG_X86_32
	newregs->sp = (unsigned long)&(oldregs->sp);
	asm volatile("xorl %%eax, %%eax\n\t"
		     "movw %%ss, %%ax\n\t"
		     :"=a"(newregs->ss));
#endif
}

/*
 * This function is responsible for capturing register states if coming
 * via panic otherwise just fix up the ss and sp if coming via kernel
 * mode exception.
 */
static inline void crash_setup_regs(struct pt_regs *newregs,
				    struct pt_regs *oldregs)
{
	if (oldregs) {
		memcpy(newregs, oldregs, sizeof(*newregs));
		crash_fixup_ss_esp(newregs, oldregs);
	} else {
#ifdef CONFIG_X86_32
		asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
		asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
		asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
		asm volatile("movl %%esi,%0" : "=m"(newregs->si));
		asm volatile("movl %%edi,%0" : "=m"(newregs->di));
		asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
		asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
		asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
		asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
		asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
		asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
#else
		asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
		asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
		asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
		asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
		asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
		asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
		asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
		asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
		asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
		asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
		asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
		asm volatile("movq %%r11,%0" : "=m"(newregs->r11));
		asm volatile("movq %%r12,%0" : "=m"(newregs->r12));
		asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
		asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
		asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
		asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
#endif
		newregs->ip = (unsigned long)current_text_addr();
	}
}

#ifdef CONFIG_X86_32
asmlinkage unsigned long
relocate_kernel(unsigned long indirection_page,
		unsigned long control_page,
		unsigned long start_address,
		unsigned int has_pae,
		unsigned int preserve_context);
#else
unsigned long
relocate_kernel(unsigned long indirection_page,
		unsigned long page_list,
		unsigned long start_address,
		unsigned int preserve_context);
#endif

#define ARCH_HAS_KIMAGE_ARCH

#ifdef CONFIG_X86_32
struct kimage_arch {
	pgd_t *pgd;
#ifdef CONFIG_X86_PAE
	pmd_t *pmd0;
	pmd_t *pmd1;
#endif
	pte_t *pte0;
	pte_t *pte1;
};
#else
struct kimage_arch {
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;
};
#endif

typedef void crash_vmclear_fn(void);
extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss;

#endif /* __ASSEMBLY__ */

#endif /* _ASM_X86_KEXEC_H */