xref: /openbmc/linux/arch/x86/include/asm/kexec.h (revision 360823a09426347ea8f232b0b0b5156d0aed0302)
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_PAGE_SIZE	4096
20 # define KEXEC_CONTROL_CODE_MAX_SIZE	2048
21 
22 #ifndef __ASSEMBLY__
23 
24 #include <linux/string.h>
25 #include <linux/kernel.h>
26 
27 #include <asm/page.h>
28 #include <asm/ptrace.h>
29 #include <asm/bootparam.h>
30 
31 struct kimage;
32 
33 /*
34  * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
35  * I.e. Maximum page that is mapped directly into kernel memory,
36  * and kmap is not required.
37  *
38  * So far x86_64 is limited to 40 physical address bits.
39  */
40 #ifdef CONFIG_X86_32
41 /* Maximum physical address we can use pages from */
42 # define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
43 /* Maximum address we can reach in physical address mode */
44 # define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
45 /* Maximum address we can use for the control code buffer */
46 # define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
47 
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 /* The native architecture */
63 # define KEXEC_ARCH KEXEC_ARCH_X86_64
64 #endif
65 
66 /*
67  * This function is responsible for capturing register states if coming
68  * via panic otherwise just fix up the ss and sp if coming via kernel
69  * mode exception.
70  */
crash_setup_regs(struct pt_regs * newregs,struct pt_regs * oldregs)71 static inline void crash_setup_regs(struct pt_regs *newregs,
72 				    struct pt_regs *oldregs)
73 {
74 	if (oldregs) {
75 		memcpy(newregs, oldregs, sizeof(*newregs));
76 	} else {
77 #ifdef CONFIG_X86_32
78 		asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
79 		asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
80 		asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
81 		asm volatile("movl %%esi,%0" : "=m"(newregs->si));
82 		asm volatile("movl %%edi,%0" : "=m"(newregs->di));
83 		asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
84 		asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
85 		asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
86 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
87 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
88 		asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
89 		asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
90 		asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
91 #else
92 		asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
93 		asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
94 		asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
95 		asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
96 		asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
97 		asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
98 		asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
99 		asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
100 		asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
101 		asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
102 		asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
103 		asm volatile("movq %%r11,%0" : "=m"(newregs->r11));
104 		asm volatile("movq %%r12,%0" : "=m"(newregs->r12));
105 		asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
106 		asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
107 		asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
108 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
109 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
110 		asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
111 #endif
112 		newregs->ip = _THIS_IP_;
113 	}
114 }
115 
116 #ifdef CONFIG_X86_32
117 asmlinkage unsigned long
118 relocate_kernel(unsigned long indirection_page,
119 		unsigned long control_page,
120 		unsigned long start_address,
121 		unsigned int has_pae,
122 		unsigned int preserve_context);
123 #else
124 unsigned long
125 relocate_kernel(unsigned long indirection_page,
126 		unsigned long page_list,
127 		unsigned long start_address,
128 		unsigned int preserve_context,
129 		unsigned int host_mem_enc_active);
130 #endif
131 
132 #define ARCH_HAS_KIMAGE_ARCH
133 
134 #ifdef CONFIG_X86_32
135 struct kimage_arch {
136 	pgd_t *pgd;
137 #ifdef CONFIG_X86_PAE
138 	pmd_t *pmd0;
139 	pmd_t *pmd1;
140 #endif
141 	pte_t *pte0;
142 	pte_t *pte1;
143 };
144 #else
145 struct kimage_arch {
146 	/*
147 	 * This is a kimage control page, as it must not overlap with either
148 	 * source or destination address ranges.
149 	 */
150 	pgd_t *pgd;
151 	/*
152 	 * The virtual mapping of the control code page itself is used only
153 	 * during the transition, while the current kernel's pages are all
154 	 * in place. Thus the intermediate page table pages used to map it
155 	 * are not control pages, but instead just normal pages obtained
156 	 * with get_zeroed_page(). And have to be tracked (below) so that
157 	 * they can be freed.
158 	 */
159 	p4d_t *p4d;
160 	pud_t *pud;
161 	pmd_t *pmd;
162 	pte_t *pte;
163 };
164 #endif /* CONFIG_X86_32 */
165 
166 #ifdef CONFIG_X86_64
167 /*
168  * Number of elements and order of elements in this structure should match
169  * with the ones in arch/x86/purgatory/entry64.S. If you make a change here
170  * make an appropriate change in purgatory too.
171  */
172 struct kexec_entry64_regs {
173 	uint64_t rax;
174 	uint64_t rcx;
175 	uint64_t rdx;
176 	uint64_t rbx;
177 	uint64_t rsp;
178 	uint64_t rbp;
179 	uint64_t rsi;
180 	uint64_t rdi;
181 	uint64_t r8;
182 	uint64_t r9;
183 	uint64_t r10;
184 	uint64_t r11;
185 	uint64_t r12;
186 	uint64_t r13;
187 	uint64_t r14;
188 	uint64_t r15;
189 	uint64_t rip;
190 };
191 
192 extern int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages,
193 				       gfp_t gfp);
194 #define arch_kexec_post_alloc_pages arch_kexec_post_alloc_pages
195 
196 extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages);
197 #define arch_kexec_pre_free_pages arch_kexec_pre_free_pages
198 
199 void arch_kexec_protect_crashkres(void);
200 #define arch_kexec_protect_crashkres arch_kexec_protect_crashkres
201 
202 void arch_kexec_unprotect_crashkres(void);
203 #define arch_kexec_unprotect_crashkres arch_kexec_unprotect_crashkres
204 
205 #ifdef CONFIG_KEXEC_FILE
206 struct purgatory_info;
207 int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
208 				     Elf_Shdr *section,
209 				     const Elf_Shdr *relsec,
210 				     const Elf_Shdr *symtab);
211 #define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add
212 
213 int arch_kimage_file_post_load_cleanup(struct kimage *image);
214 #define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup
215 #endif
216 #endif
217 
218 extern void kdump_nmi_shootdown_cpus(void);
219 
220 #ifdef CONFIG_CRASH_HOTPLUG
221 void arch_crash_handle_hotplug_event(struct kimage *image);
222 #define arch_crash_handle_hotplug_event arch_crash_handle_hotplug_event
223 
224 #ifdef CONFIG_HOTPLUG_CPU
225 int arch_crash_hotplug_cpu_support(void);
226 #define crash_hotplug_cpu_support arch_crash_hotplug_cpu_support
227 #endif
228 
229 #ifdef CONFIG_MEMORY_HOTPLUG
230 int arch_crash_hotplug_memory_support(void);
231 #define crash_hotplug_memory_support arch_crash_hotplug_memory_support
232 #endif
233 
234 unsigned int arch_crash_get_elfcorehdr_size(void);
235 #define crash_get_elfcorehdr_size arch_crash_get_elfcorehdr_size
236 #endif
237 
238 #endif /* __ASSEMBLY__ */
239 
240 #endif /* _ASM_X86_KEXEC_H */
241