xref: /openbmc/linux/arch/x86/include/asm/kexec.h (revision e2c75e76)
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 
25 #include <asm/page.h>
26 #include <asm/ptrace.h>
27 #include <asm/bootparam.h>
28 
29 struct kimage;
30 
31 /*
32  * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
33  * I.e. Maximum page that is mapped directly into kernel memory,
34  * and kmap is not required.
35  *
36  * So far x86_64 is limited to 40 physical address bits.
37  */
38 #ifdef CONFIG_X86_32
39 /* Maximum physical address we can use pages from */
40 # define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
41 /* Maximum address we can reach in physical address mode */
42 # define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
43 /* Maximum address we can use for the control code buffer */
44 # define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
45 
46 # define KEXEC_CONTROL_PAGE_SIZE	4096
47 
48 /* The native architecture */
49 # define KEXEC_ARCH KEXEC_ARCH_386
50 
51 /* We can also handle crash dumps from 64 bit kernel. */
52 # define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
53 #else
54 /* Maximum physical address we can use pages from */
55 # define KEXEC_SOURCE_MEMORY_LIMIT      (MAXMEM-1)
56 /* Maximum address we can reach in physical address mode */
57 # define KEXEC_DESTINATION_MEMORY_LIMIT (MAXMEM-1)
58 /* Maximum address we can use for the control pages */
59 # define KEXEC_CONTROL_MEMORY_LIMIT     (MAXMEM-1)
60 
61 /* Allocate one page for the pdp and the second for the code */
62 # define KEXEC_CONTROL_PAGE_SIZE  (4096UL + 4096UL)
63 
64 /* The native architecture */
65 # define KEXEC_ARCH KEXEC_ARCH_X86_64
66 #endif
67 
68 /* Memory to backup during crash kdump */
69 #define KEXEC_BACKUP_SRC_START	(0UL)
70 #define KEXEC_BACKUP_SRC_END	(640 * 1024UL)	/* 640K */
71 
72 /*
73  * CPU does not save ss and sp on stack if execution is already
74  * running in kernel mode at the time of NMI occurrence. This code
75  * fixes it.
76  */
77 static inline void crash_fixup_ss_esp(struct pt_regs *newregs,
78 				      struct pt_regs *oldregs)
79 {
80 #ifdef CONFIG_X86_32
81 	newregs->sp = (unsigned long)&(oldregs->sp);
82 	asm volatile("xorl %%eax, %%eax\n\t"
83 		     "movw %%ss, %%ax\n\t"
84 		     :"=a"(newregs->ss));
85 #endif
86 }
87 
88 /*
89  * This function is responsible for capturing register states if coming
90  * via panic otherwise just fix up the ss and sp if coming via kernel
91  * mode exception.
92  */
93 static inline void crash_setup_regs(struct pt_regs *newregs,
94 				    struct pt_regs *oldregs)
95 {
96 	if (oldregs) {
97 		memcpy(newregs, oldregs, sizeof(*newregs));
98 		crash_fixup_ss_esp(newregs, oldregs);
99 	} else {
100 #ifdef CONFIG_X86_32
101 		asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
102 		asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
103 		asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
104 		asm volatile("movl %%esi,%0" : "=m"(newregs->si));
105 		asm volatile("movl %%edi,%0" : "=m"(newregs->di));
106 		asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
107 		asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
108 		asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
109 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
110 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
111 		asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
112 		asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
113 		asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
114 #else
115 		asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
116 		asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
117 		asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
118 		asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
119 		asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
120 		asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
121 		asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
122 		asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
123 		asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
124 		asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
125 		asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
126 		asm volatile("movq %%r11,%0" : "=m"(newregs->r11));
127 		asm volatile("movq %%r12,%0" : "=m"(newregs->r12));
128 		asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
129 		asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
130 		asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
131 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
132 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
133 		asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
134 #endif
135 		newregs->ip = (unsigned long)current_text_addr();
136 	}
137 }
138 
139 #ifdef CONFIG_X86_32
140 asmlinkage unsigned long
141 relocate_kernel(unsigned long indirection_page,
142 		unsigned long control_page,
143 		unsigned long start_address,
144 		unsigned int has_pae,
145 		unsigned int preserve_context);
146 #else
147 unsigned long
148 relocate_kernel(unsigned long indirection_page,
149 		unsigned long page_list,
150 		unsigned long start_address,
151 		unsigned int preserve_context,
152 		unsigned int sme_active);
153 #endif
154 
155 #define ARCH_HAS_KIMAGE_ARCH
156 
157 #ifdef CONFIG_X86_32
158 struct kimage_arch {
159 	pgd_t *pgd;
160 #ifdef CONFIG_X86_PAE
161 	pmd_t *pmd0;
162 	pmd_t *pmd1;
163 #endif
164 	pte_t *pte0;
165 	pte_t *pte1;
166 };
167 #else
168 struct kimage_arch {
169 	p4d_t *p4d;
170 	pud_t *pud;
171 	pmd_t *pmd;
172 	pte_t *pte;
173 	/* Details of backup region */
174 	unsigned long backup_src_start;
175 	unsigned long backup_src_sz;
176 
177 	/* Physical address of backup segment */
178 	unsigned long backup_load_addr;
179 
180 	/* Core ELF header buffer */
181 	void *elf_headers;
182 	unsigned long elf_headers_sz;
183 	unsigned long elf_load_addr;
184 };
185 #endif /* CONFIG_X86_32 */
186 
187 #ifdef CONFIG_X86_64
188 /*
189  * Number of elements and order of elements in this structure should match
190  * with the ones in arch/x86/purgatory/entry64.S. If you make a change here
191  * make an appropriate change in purgatory too.
192  */
193 struct kexec_entry64_regs {
194 	uint64_t rax;
195 	uint64_t rcx;
196 	uint64_t rdx;
197 	uint64_t rbx;
198 	uint64_t rsp;
199 	uint64_t rbp;
200 	uint64_t rsi;
201 	uint64_t rdi;
202 	uint64_t r8;
203 	uint64_t r9;
204 	uint64_t r10;
205 	uint64_t r11;
206 	uint64_t r12;
207 	uint64_t r13;
208 	uint64_t r14;
209 	uint64_t r15;
210 	uint64_t rip;
211 };
212 
213 extern int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages,
214 				       gfp_t gfp);
215 #define arch_kexec_post_alloc_pages arch_kexec_post_alloc_pages
216 
217 extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages);
218 #define arch_kexec_pre_free_pages arch_kexec_pre_free_pages
219 
220 #endif
221 
222 typedef void crash_vmclear_fn(void);
223 extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss;
224 extern void kdump_nmi_shootdown_cpus(void);
225 
226 #endif /* __ASSEMBLY__ */
227 
228 #endif /* _ASM_X86_KEXEC_H */
229