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
30struct 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 */
78static 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 */
94static 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
141asmlinkage unsigned long
142relocate_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
148unsigned long
149relocate_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
159struct 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
169struct 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 */
194struct 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
214extern 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
218extern 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
223typedef void crash_vmclear_fn(void);
224extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss;
225extern void kdump_nmi_shootdown_cpus(void);
226
227#endif /* __ASSEMBLY__ */
228
229#endif /* _ASM_X86_KEXEC_H */
230