xref: /openbmc/linux/arch/x86/include/asm/kexec.h (revision 5d331b7f)
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 /* Memory to backup during crash kdump */
70 #define KEXEC_BACKUP_SRC_START	(0UL)
71 #define KEXEC_BACKUP_SRC_END	(640 * 1024UL - 1)	/* 640K */
72 
73 /*
74  * CPU does not save ss and sp on stack if execution is already
75  * running in kernel mode at the time of NMI occurrence. This code
76  * fixes it.
77  */
78 static inline void crash_fixup_ss_esp(struct pt_regs *newregs,
79 				      struct pt_regs *oldregs)
80 {
81 #ifdef CONFIG_X86_32
82 	newregs->sp = (unsigned long)&(oldregs->sp);
83 	asm volatile("xorl %%eax, %%eax\n\t"
84 		     "movw %%ss, %%ax\n\t"
85 		     :"=a"(newregs->ss));
86 #endif
87 }
88 
89 /*
90  * This function is responsible for capturing register states if coming
91  * via panic otherwise just fix up the ss and sp if coming via kernel
92  * mode exception.
93  */
94 static inline void crash_setup_regs(struct pt_regs *newregs,
95 				    struct pt_regs *oldregs)
96 {
97 	if (oldregs) {
98 		memcpy(newregs, oldregs, sizeof(*newregs));
99 		crash_fixup_ss_esp(newregs, oldregs);
100 	} else {
101 #ifdef CONFIG_X86_32
102 		asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
103 		asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
104 		asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
105 		asm volatile("movl %%esi,%0" : "=m"(newregs->si));
106 		asm volatile("movl %%edi,%0" : "=m"(newregs->di));
107 		asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
108 		asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
109 		asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
110 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
111 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
112 		asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
113 		asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
114 		asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
115 #else
116 		asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
117 		asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
118 		asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
119 		asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
120 		asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
121 		asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
122 		asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
123 		asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
124 		asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
125 		asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
126 		asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
127 		asm volatile("movq %%r11,%0" : "=m"(newregs->r11));
128 		asm volatile("movq %%r12,%0" : "=m"(newregs->r12));
129 		asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
130 		asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
131 		asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
132 		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
133 		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
134 		asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
135 #endif
136 		newregs->ip = _THIS_IP_;
137 	}
138 }
139 
140 #ifdef CONFIG_X86_32
141 asmlinkage unsigned long
142 relocate_kernel(unsigned long indirection_page,
143 		unsigned long control_page,
144 		unsigned long start_address,
145 		unsigned int has_pae,
146 		unsigned int preserve_context);
147 #else
148 unsigned long
149 relocate_kernel(unsigned long indirection_page,
150 		unsigned long page_list,
151 		unsigned long start_address,
152 		unsigned int preserve_context,
153 		unsigned int sme_active);
154 #endif
155 
156 #define ARCH_HAS_KIMAGE_ARCH
157 
158 #ifdef CONFIG_X86_32
159 struct kimage_arch {
160 	pgd_t *pgd;
161 #ifdef CONFIG_X86_PAE
162 	pmd_t *pmd0;
163 	pmd_t *pmd1;
164 #endif
165 	pte_t *pte0;
166 	pte_t *pte1;
167 };
168 #else
169 struct kimage_arch {
170 	p4d_t *p4d;
171 	pud_t *pud;
172 	pmd_t *pmd;
173 	pte_t *pte;
174 	/* Details of backup region */
175 	unsigned long backup_src_start;
176 	unsigned long backup_src_sz;
177 
178 	/* Physical address of backup segment */
179 	unsigned long backup_load_addr;
180 
181 	/* Core ELF header buffer */
182 	void *elf_headers;
183 	unsigned long elf_headers_sz;
184 	unsigned long elf_load_addr;
185 };
186 #endif /* CONFIG_X86_32 */
187 
188 #ifdef CONFIG_X86_64
189 /*
190  * Number of elements and order of elements in this structure should match
191  * with the ones in arch/x86/purgatory/entry64.S. If you make a change here
192  * make an appropriate change in purgatory too.
193  */
194 struct kexec_entry64_regs {
195 	uint64_t rax;
196 	uint64_t rcx;
197 	uint64_t rdx;
198 	uint64_t rbx;
199 	uint64_t rsp;
200 	uint64_t rbp;
201 	uint64_t rsi;
202 	uint64_t rdi;
203 	uint64_t r8;
204 	uint64_t r9;
205 	uint64_t r10;
206 	uint64_t r11;
207 	uint64_t r12;
208 	uint64_t r13;
209 	uint64_t r14;
210 	uint64_t r15;
211 	uint64_t rip;
212 };
213 
214 extern int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages,
215 				       gfp_t gfp);
216 #define arch_kexec_post_alloc_pages arch_kexec_post_alloc_pages
217 
218 extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages);
219 #define arch_kexec_pre_free_pages arch_kexec_pre_free_pages
220 
221 #endif
222 
223 typedef void crash_vmclear_fn(void);
224 extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss;
225 extern void kdump_nmi_shootdown_cpus(void);
226 
227 #endif /* __ASSEMBLY__ */
228 
229 #endif /* _ASM_X86_KEXEC_H */
230