xref: /openbmc/linux/arch/x86/include/asm/kexec.h (revision 4f3db074)
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 #include <asm/bootparam.h>
27 
28 struct kimage;
29 
30 /*
31  * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
32  * I.e. Maximum page that is mapped directly into kernel memory,
33  * and kmap is not required.
34  *
35  * So far x86_64 is limited to 40 physical address bits.
36  */
37 #ifdef CONFIG_X86_32
38 /* Maximum physical address we can use pages from */
39 # define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
40 /* Maximum address we can reach in physical address mode */
41 # define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
42 /* Maximum address we can use for the control code buffer */
43 # define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
44 
45 # define KEXEC_CONTROL_PAGE_SIZE	4096
46 
47 /* The native architecture */
48 # define KEXEC_ARCH KEXEC_ARCH_386
49 
50 /* We can also handle crash dumps from 64 bit kernel. */
51 # define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
52 #else
53 /* Maximum physical address we can use pages from */
54 # define KEXEC_SOURCE_MEMORY_LIMIT      (MAXMEM-1)
55 /* Maximum address we can reach in physical address mode */
56 # define KEXEC_DESTINATION_MEMORY_LIMIT (MAXMEM-1)
57 /* Maximum address we can use for the control pages */
58 # define KEXEC_CONTROL_MEMORY_LIMIT     (MAXMEM-1)
59 
60 /* Allocate one page for the pdp and the second for the code */
61 # define KEXEC_CONTROL_PAGE_SIZE  (4096UL + 4096UL)
62 
63 /* The native architecture */
64 # define KEXEC_ARCH KEXEC_ARCH_X86_64
65 #endif
66 
67 /* Memory to backup during crash kdump */
68 #define KEXEC_BACKUP_SRC_START	(0UL)
69 #define KEXEC_BACKUP_SRC_END	(640 * 1024UL)	/* 640K */
70 
71 /*
72  * CPU does not save ss and sp on stack if execution is already
73  * running in kernel mode at the time of NMI occurrence. This code
74  * fixes it.
75  */
76 static inline void crash_fixup_ss_esp(struct pt_regs *newregs,
77 				      struct pt_regs *oldregs)
78 {
79 #ifdef CONFIG_X86_32
80 	newregs->sp = (unsigned long)&(oldregs->sp);
81 	asm volatile("xorl %%eax, %%eax\n\t"
82 		     "movw %%ss, %%ax\n\t"
83 		     :"=a"(newregs->ss));
84 #endif
85 }
86 
87 /*
88  * This function is responsible for capturing register states if coming
89  * via panic otherwise just fix up the ss and sp if coming via kernel
90  * mode exception.
91  */
92 static inline void crash_setup_regs(struct pt_regs *newregs,
93 				    struct pt_regs *oldregs)
94 {
95 	if (oldregs) {
96 		memcpy(newregs, oldregs, sizeof(*newregs));
97 		crash_fixup_ss_esp(newregs, oldregs);
98 	} else {
99 #ifdef CONFIG_X86_32
100 		asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
101 		asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
102 		asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
103 		asm volatile("movl %%esi,%0" : "=m"(newregs->si));
104 		asm volatile("movl %%edi,%0" : "=m"(newregs->di));
105 		asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
106 		asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
107 		asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
108 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
109 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
110 		asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
111 		asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
112 		asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
113 #else
114 		asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
115 		asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
116 		asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
117 		asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
118 		asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
119 		asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
120 		asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
121 		asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
122 		asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
123 		asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
124 		asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
125 		asm volatile("movq %%r11,%0" : "=m"(newregs->r11));
126 		asm volatile("movq %%r12,%0" : "=m"(newregs->r12));
127 		asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
128 		asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
129 		asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
130 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
131 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
132 		asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
133 #endif
134 		newregs->ip = (unsigned long)current_text_addr();
135 	}
136 }
137 
138 #ifdef CONFIG_X86_32
139 asmlinkage unsigned long
140 relocate_kernel(unsigned long indirection_page,
141 		unsigned long control_page,
142 		unsigned long start_address,
143 		unsigned int has_pae,
144 		unsigned int preserve_context);
145 #else
146 unsigned long
147 relocate_kernel(unsigned long indirection_page,
148 		unsigned long page_list,
149 		unsigned long start_address,
150 		unsigned int preserve_context);
151 #endif
152 
153 #define ARCH_HAS_KIMAGE_ARCH
154 
155 #ifdef CONFIG_X86_32
156 struct kimage_arch {
157 	pgd_t *pgd;
158 #ifdef CONFIG_X86_PAE
159 	pmd_t *pmd0;
160 	pmd_t *pmd1;
161 #endif
162 	pte_t *pte0;
163 	pte_t *pte1;
164 };
165 #else
166 struct kimage_arch {
167 	pud_t *pud;
168 	pmd_t *pmd;
169 	pte_t *pte;
170 	/* Details of backup region */
171 	unsigned long backup_src_start;
172 	unsigned long backup_src_sz;
173 
174 	/* Physical address of backup segment */
175 	unsigned long backup_load_addr;
176 
177 	/* Core ELF header buffer */
178 	void *elf_headers;
179 	unsigned long elf_headers_sz;
180 	unsigned long elf_load_addr;
181 };
182 #endif /* CONFIG_X86_32 */
183 
184 #ifdef CONFIG_X86_64
185 /*
186  * Number of elements and order of elements in this structure should match
187  * with the ones in arch/x86/purgatory/entry64.S. If you make a change here
188  * make an appropriate change in purgatory too.
189  */
190 struct kexec_entry64_regs {
191 	uint64_t rax;
192 	uint64_t rcx;
193 	uint64_t rdx;
194 	uint64_t rbx;
195 	uint64_t rsp;
196 	uint64_t rbp;
197 	uint64_t rsi;
198 	uint64_t rdi;
199 	uint64_t r8;
200 	uint64_t r9;
201 	uint64_t r10;
202 	uint64_t r11;
203 	uint64_t r12;
204 	uint64_t r13;
205 	uint64_t r14;
206 	uint64_t r15;
207 	uint64_t rip;
208 };
209 #endif
210 
211 typedef void crash_vmclear_fn(void);
212 extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss;
213 
214 #endif /* __ASSEMBLY__ */
215 
216 #endif /* _ASM_X86_KEXEC_H */
217