xref: /linux-6.15/include/linux/kexec.h (revision 4dbed85a)
1 #ifndef LINUX_KEXEC_H
2 #define LINUX_KEXEC_H
3 
4 #ifdef CONFIG_KEXEC
5 #include <linux/types.h>
6 #include <linux/list.h>
7 #include <linux/linkage.h>
8 #include <linux/compat.h>
9 #include <linux/ioport.h>
10 #include <linux/elfcore.h>
11 #include <linux/elf.h>
12 #include <asm/kexec.h>
13 
14 /* Verify architecture specific macros are defined */
15 
16 #ifndef KEXEC_SOURCE_MEMORY_LIMIT
17 #error KEXEC_SOURCE_MEMORY_LIMIT not defined
18 #endif
19 
20 #ifndef KEXEC_DESTINATION_MEMORY_LIMIT
21 #error KEXEC_DESTINATION_MEMORY_LIMIT not defined
22 #endif
23 
24 #ifndef KEXEC_CONTROL_MEMORY_LIMIT
25 #error KEXEC_CONTROL_MEMORY_LIMIT not defined
26 #endif
27 
28 #ifndef KEXEC_CONTROL_CODE_SIZE
29 #error KEXEC_CONTROL_CODE_SIZE not defined
30 #endif
31 
32 #ifndef KEXEC_ARCH
33 #error KEXEC_ARCH not defined
34 #endif
35 
36 #define KEXEC_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4)
37 #define KEXEC_CORE_NOTE_NAME "CORE"
38 #define KEXEC_CORE_NOTE_NAME_BYTES ALIGN(sizeof(KEXEC_CORE_NOTE_NAME), 4)
39 #define KEXEC_CORE_NOTE_DESC_BYTES ALIGN(sizeof(struct elf_prstatus), 4)
40 /*
41  * The per-cpu notes area is a list of notes terminated by a "NULL"
42  * note header.  For kdump, the code in vmcore.c runs in the context
43  * of the second kernel to combine them into one note.
44  */
45 #define KEXEC_NOTE_BYTES ( (KEXEC_NOTE_HEAD_BYTES * 2) +		\
46 			    KEXEC_CORE_NOTE_NAME_BYTES +		\
47 			    KEXEC_CORE_NOTE_DESC_BYTES )
48 
49 /*
50  * This structure is used to hold the arguments that are used when loading
51  * kernel binaries.
52  */
53 
54 typedef unsigned long kimage_entry_t;
55 #define IND_DESTINATION  0x1
56 #define IND_INDIRECTION  0x2
57 #define IND_DONE         0x4
58 #define IND_SOURCE       0x8
59 
60 #define KEXEC_SEGMENT_MAX 16
61 struct kexec_segment {
62 	void __user *buf;
63 	size_t bufsz;
64 	unsigned long mem;	/* User space sees this as a (void *) ... */
65 	size_t memsz;
66 };
67 
68 #ifdef CONFIG_COMPAT
69 struct compat_kexec_segment {
70 	compat_uptr_t buf;
71 	compat_size_t bufsz;
72 	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
73 	compat_size_t memsz;
74 };
75 #endif
76 
77 struct kimage {
78 	kimage_entry_t head;
79 	kimage_entry_t *entry;
80 	kimage_entry_t *last_entry;
81 
82 	unsigned long destination;
83 
84 	unsigned long start;
85 	struct page *control_code_page;
86 
87 	unsigned long nr_segments;
88 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
89 
90 	struct list_head control_pages;
91 	struct list_head dest_pages;
92 	struct list_head unuseable_pages;
93 
94 	/* Address of next control page to allocate for crash kernels. */
95 	unsigned long control_page;
96 
97 	/* Flags to indicate special processing */
98 	unsigned int type : 1;
99 #define KEXEC_TYPE_DEFAULT 0
100 #define KEXEC_TYPE_CRASH   1
101 };
102 
103 
104 
105 /* kexec interface functions */
106 extern NORET_TYPE void machine_kexec(struct kimage *image) ATTRIB_NORET;
107 extern int machine_kexec_prepare(struct kimage *image);
108 extern void machine_kexec_cleanup(struct kimage *image);
109 extern asmlinkage long sys_kexec_load(unsigned long entry,
110 					unsigned long nr_segments,
111 					struct kexec_segment __user *segments,
112 					unsigned long flags);
113 #ifdef CONFIG_COMPAT
114 extern asmlinkage long compat_sys_kexec_load(unsigned long entry,
115 				unsigned long nr_segments,
116 				struct compat_kexec_segment __user *segments,
117 				unsigned long flags);
118 #endif
119 extern struct page *kimage_alloc_control_pages(struct kimage *image,
120 						unsigned int order);
121 extern void crash_kexec(struct pt_regs *);
122 int kexec_should_crash(struct task_struct *);
123 void crash_save_cpu(struct pt_regs *regs, int cpu);
124 void crash_save_vmcoreinfo(void);
125 void arch_crash_save_vmcoreinfo(void);
126 void vmcoreinfo_append_str(const char *fmt, ...)
127 	__attribute__ ((format (printf, 1, 2)));
128 unsigned long paddr_vmcoreinfo_note(void);
129 
130 #define VMCOREINFO_SYMBOL(name) \
131 	vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name)
132 #define VMCOREINFO_SIZE(name) \
133 	vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
134 			      (unsigned long)sizeof(struct name))
135 #define VMCOREINFO_TYPEDEF_SIZE(name) \
136 	vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
137 			      (unsigned long)sizeof(name))
138 #define VMCOREINFO_OFFSET(name, field) \
139 	vmcoreinfo_append_str("OFFSET(%s.%s)=%lu\n", #name, #field, \
140 			      (unsigned long)&(((struct name *)0)->field))
141 #define VMCOREINFO_LENGTH(name, value) \
142 	vmcoreinfo_append_str("LENGTH(%s)=%lu\n", #name, (unsigned long)value)
143 #define VMCOREINFO_NUMBER(name) \
144 	vmcoreinfo_append_str("NUMBER(%s)=%ld\n", #name, (long)name)
145 #define VMCOREINFO_CONFIG(name) \
146 	vmcoreinfo_append_str("CONFIG_%s=y\n", #name)
147 
148 extern struct kimage *kexec_image;
149 extern struct kimage *kexec_crash_image;
150 
151 #ifndef kexec_flush_icache_page
152 #define kexec_flush_icache_page(page)
153 #endif
154 
155 #define KEXEC_ON_CRASH  0x00000001
156 #define KEXEC_ARCH_MASK 0xffff0000
157 
158 /* These values match the ELF architecture values.
159  * Unless there is a good reason that should continue to be the case.
160  */
161 #define KEXEC_ARCH_DEFAULT ( 0 << 16)
162 #define KEXEC_ARCH_386     ( 3 << 16)
163 #define KEXEC_ARCH_X86_64  (62 << 16)
164 #define KEXEC_ARCH_PPC     (20 << 16)
165 #define KEXEC_ARCH_PPC64   (21 << 16)
166 #define KEXEC_ARCH_IA_64   (50 << 16)
167 #define KEXEC_ARCH_ARM     (40 << 16)
168 #define KEXEC_ARCH_S390    (22 << 16)
169 #define KEXEC_ARCH_SH      (42 << 16)
170 #define KEXEC_ARCH_MIPS_LE (10 << 16)
171 #define KEXEC_ARCH_MIPS    ( 8 << 16)
172 
173 #define KEXEC_FLAGS    (KEXEC_ON_CRASH)  /* List of defined/legal kexec flags */
174 
175 #define VMCOREINFO_BYTES           (4096)
176 #define VMCOREINFO_NOTE_NAME       "VMCOREINFO"
177 #define VMCOREINFO_NOTE_NAME_BYTES ALIGN(sizeof(VMCOREINFO_NOTE_NAME), 4)
178 #define VMCOREINFO_NOTE_SIZE       (KEXEC_NOTE_HEAD_BYTES*2 + VMCOREINFO_BYTES \
179 				    + VMCOREINFO_NOTE_NAME_BYTES)
180 
181 /* Location of a reserved region to hold the crash kernel.
182  */
183 extern struct resource crashk_res;
184 typedef u32 note_buf_t[KEXEC_NOTE_BYTES/4];
185 extern note_buf_t *crash_notes;
186 extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
187 extern size_t vmcoreinfo_size;
188 extern size_t vmcoreinfo_max_size;
189 
190 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
191 		unsigned long long *crash_size, unsigned long long *crash_base);
192 
193 #else /* !CONFIG_KEXEC */
194 struct pt_regs;
195 struct task_struct;
196 static inline void crash_kexec(struct pt_regs *regs) { }
197 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
198 #endif /* CONFIG_KEXEC */
199 #endif /* LINUX_KEXEC_H */
200