xref: /openbmc/linux/arch/x86/include/asm/kexec.h (revision 7fc96d71)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_KEXEC_H
3 #define _ASM_X86_KEXEC_H
4 
5 #ifdef CONFIG_X86_32
6 # define PA_CONTROL_PAGE	0
7 # define VA_CONTROL_PAGE	1
8 # define PA_PGD			2
9 # define PA_SWAP_PAGE		3
10 # define PAGES_NR		4
11 #else
12 # define PA_CONTROL_PAGE	0
13 # define VA_CONTROL_PAGE	1
14 # define PA_TABLE_PAGE		2
15 # define PA_SWAP_PAGE		3
16 # define PAGES_NR		4
17 #endif
18 
19 # define KEXEC_CONTROL_CODE_MAX_SIZE	2048
20 
21 #ifndef __ASSEMBLY__
22 
23 #include <linux/string.h>
24 #include <linux/kernel.h>
25 
26 #include <asm/page.h>
27 #include <asm/ptrace.h>
28 #include <asm/bootparam.h>
29 
30 struct kimage;
31 
32 /*
33  * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
34  * I.e. Maximum page that is mapped directly into kernel memory,
35  * and kmap is not required.
36  *
37  * So far x86_64 is limited to 40 physical address bits.
38  */
39 #ifdef CONFIG_X86_32
40 /* Maximum physical address we can use pages from */
41 # define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
42 /* Maximum address we can reach in physical address mode */
43 # define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
44 /* Maximum address we can use for the control code buffer */
45 # define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
46 
47 # define KEXEC_CONTROL_PAGE_SIZE	4096
48 
49 /* The native architecture */
50 # define KEXEC_ARCH KEXEC_ARCH_386
51 
52 /* We can also handle crash dumps from 64 bit kernel. */
53 # define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
54 #else
55 /* Maximum physical address we can use pages from */
56 # define KEXEC_SOURCE_MEMORY_LIMIT      (MAXMEM-1)
57 /* Maximum address we can reach in physical address mode */
58 # define KEXEC_DESTINATION_MEMORY_LIMIT (MAXMEM-1)
59 /* Maximum address we can use for the control pages */
60 # define KEXEC_CONTROL_MEMORY_LIMIT     (MAXMEM-1)
61 
62 /* Allocate one page for the pdp and the second for the code */
63 # define KEXEC_CONTROL_PAGE_SIZE  (4096UL + 4096UL)
64 
65 /* The native architecture */
66 # define KEXEC_ARCH KEXEC_ARCH_X86_64
67 #endif
68 
69 /*
70  * This function is responsible for capturing register states if coming
71  * via panic otherwise just fix up the ss and sp if coming via kernel
72  * mode exception.
73  */
74 static inline void crash_setup_regs(struct pt_regs *newregs,
75 				    struct pt_regs *oldregs)
76 {
77 	if (oldregs) {
78 		memcpy(newregs, oldregs, sizeof(*newregs));
79 	} else {
80 #ifdef CONFIG_X86_32
81 		asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
82 		asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
83 		asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
84 		asm volatile("movl %%esi,%0" : "=m"(newregs->si));
85 		asm volatile("movl %%edi,%0" : "=m"(newregs->di));
86 		asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
87 		asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
88 		asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
89 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
90 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
91 		asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
92 		asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
93 		asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
94 #else
95 		asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
96 		asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
97 		asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
98 		asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
99 		asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
100 		asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
101 		asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
102 		asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
103 		asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
104 		asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
105 		asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
106 		asm volatile("movq %%r11,%0" : "=m"(newregs->r11));
107 		asm volatile("movq %%r12,%0" : "=m"(newregs->r12));
108 		asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
109 		asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
110 		asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
111 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
112 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
113 		asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
114 #endif
115 		newregs->ip = _THIS_IP_;
116 	}
117 }
118 
119 #ifdef CONFIG_X86_32
120 asmlinkage unsigned long
121 relocate_kernel(unsigned long indirection_page,
122 		unsigned long control_page,
123 		unsigned long start_address,
124 		unsigned int has_pae,
125 		unsigned int preserve_context);
126 #else
127 unsigned long
128 relocate_kernel(unsigned long indirection_page,
129 		unsigned long page_list,
130 		unsigned long start_address,
131 		unsigned int preserve_context,
132 		unsigned int host_mem_enc_active);
133 #endif
134 
135 #define ARCH_HAS_KIMAGE_ARCH
136 
137 #ifdef CONFIG_X86_32
138 struct kimage_arch {
139 	pgd_t *pgd;
140 #ifdef CONFIG_X86_PAE
141 	pmd_t *pmd0;
142 	pmd_t *pmd1;
143 #endif
144 	pte_t *pte0;
145 	pte_t *pte1;
146 };
147 #else
148 struct kimage_arch {
149 	p4d_t *p4d;
150 	pud_t *pud;
151 	pmd_t *pmd;
152 	pte_t *pte;
153 };
154 #endif /* CONFIG_X86_32 */
155 
156 #ifdef CONFIG_X86_64
157 /*
158  * Number of elements and order of elements in this structure should match
159  * with the ones in arch/x86/purgatory/entry64.S. If you make a change here
160  * make an appropriate change in purgatory too.
161  */
162 struct kexec_entry64_regs {
163 	uint64_t rax;
164 	uint64_t rcx;
165 	uint64_t rdx;
166 	uint64_t rbx;
167 	uint64_t rsp;
168 	uint64_t rbp;
169 	uint64_t rsi;
170 	uint64_t rdi;
171 	uint64_t r8;
172 	uint64_t r9;
173 	uint64_t r10;
174 	uint64_t r11;
175 	uint64_t r12;
176 	uint64_t r13;
177 	uint64_t r14;
178 	uint64_t r15;
179 	uint64_t rip;
180 };
181 
182 extern int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages,
183 				       gfp_t gfp);
184 #define arch_kexec_post_alloc_pages arch_kexec_post_alloc_pages
185 
186 extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages);
187 #define arch_kexec_pre_free_pages arch_kexec_pre_free_pages
188 
189 #ifdef CONFIG_KEXEC_FILE
190 struct purgatory_info;
191 int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
192 				     Elf_Shdr *section,
193 				     const Elf_Shdr *relsec,
194 				     const Elf_Shdr *symtab);
195 #define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add
196 #endif
197 #endif
198 
199 typedef void crash_vmclear_fn(void);
200 extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss;
201 extern void kdump_nmi_shootdown_cpus(void);
202 
203 #endif /* __ASSEMBLY__ */
204 
205 #endif /* _ASM_X86_KEXEC_H */
206