xref: /openbmc/linux/arch/x86/include/asm/kexec.h (revision 39b6f3aa)
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      (MAXMEM-1)
52 /* Maximum address we can reach in physical address mode */
53 # define KEXEC_DESTINATION_MEMORY_LIMIT (MAXMEM-1)
54 /* Maximum address we can use for the control pages */
55 # define KEXEC_CONTROL_MEMORY_LIMIT     (MAXMEM-1)
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 {
160 	pud_t *pud;
161 	pmd_t *pmd;
162 	pte_t *pte;
163 };
164 #endif
165 
166 typedef void crash_vmclear_fn(void);
167 extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss;
168 
169 #endif /* __ASSEMBLY__ */
170 
171 #endif /* _ASM_X86_KEXEC_H */
172