xref: /openbmc/linux/include/linux/kexec.h (revision a8fe58ce)
1 #ifndef LINUX_KEXEC_H
2 #define LINUX_KEXEC_H
3 
4 #define IND_DESTINATION_BIT 0
5 #define IND_INDIRECTION_BIT 1
6 #define IND_DONE_BIT        2
7 #define IND_SOURCE_BIT      3
8 
9 #define IND_DESTINATION  (1 << IND_DESTINATION_BIT)
10 #define IND_INDIRECTION  (1 << IND_INDIRECTION_BIT)
11 #define IND_DONE         (1 << IND_DONE_BIT)
12 #define IND_SOURCE       (1 << IND_SOURCE_BIT)
13 #define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE)
14 
15 #if !defined(__ASSEMBLY__)
16 
17 #include <uapi/linux/kexec.h>
18 
19 #ifdef CONFIG_KEXEC_CORE
20 #include <linux/list.h>
21 #include <linux/linkage.h>
22 #include <linux/compat.h>
23 #include <linux/ioport.h>
24 #include <linux/elfcore.h>
25 #include <linux/elf.h>
26 #include <linux/module.h>
27 #include <asm/kexec.h>
28 
29 /* Verify architecture specific macros are defined */
30 
31 #ifndef KEXEC_SOURCE_MEMORY_LIMIT
32 #error KEXEC_SOURCE_MEMORY_LIMIT not defined
33 #endif
34 
35 #ifndef KEXEC_DESTINATION_MEMORY_LIMIT
36 #error KEXEC_DESTINATION_MEMORY_LIMIT not defined
37 #endif
38 
39 #ifndef KEXEC_CONTROL_MEMORY_LIMIT
40 #error KEXEC_CONTROL_MEMORY_LIMIT not defined
41 #endif
42 
43 #ifndef KEXEC_CONTROL_MEMORY_GFP
44 #define KEXEC_CONTROL_MEMORY_GFP GFP_KERNEL
45 #endif
46 
47 #ifndef KEXEC_CONTROL_PAGE_SIZE
48 #error KEXEC_CONTROL_PAGE_SIZE not defined
49 #endif
50 
51 #ifndef KEXEC_ARCH
52 #error KEXEC_ARCH not defined
53 #endif
54 
55 #ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
56 #define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
57 #endif
58 
59 #ifndef KEXEC_CRASH_MEM_ALIGN
60 #define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
61 #endif
62 
63 #define KEXEC_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4)
64 #define KEXEC_CORE_NOTE_NAME "CORE"
65 #define KEXEC_CORE_NOTE_NAME_BYTES ALIGN(sizeof(KEXEC_CORE_NOTE_NAME), 4)
66 #define KEXEC_CORE_NOTE_DESC_BYTES ALIGN(sizeof(struct elf_prstatus), 4)
67 /*
68  * The per-cpu notes area is a list of notes terminated by a "NULL"
69  * note header.  For kdump, the code in vmcore.c runs in the context
70  * of the second kernel to combine them into one note.
71  */
72 #ifndef KEXEC_NOTE_BYTES
73 #define KEXEC_NOTE_BYTES ( (KEXEC_NOTE_HEAD_BYTES * 2) +		\
74 			    KEXEC_CORE_NOTE_NAME_BYTES +		\
75 			    KEXEC_CORE_NOTE_DESC_BYTES )
76 #endif
77 
78 /*
79  * This structure is used to hold the arguments that are used when loading
80  * kernel binaries.
81  */
82 
83 typedef unsigned long kimage_entry_t;
84 
85 struct kexec_segment {
86 	/*
87 	 * This pointer can point to user memory if kexec_load() system
88 	 * call is used or will point to kernel memory if
89 	 * kexec_file_load() system call is used.
90 	 *
91 	 * Use ->buf when expecting to deal with user memory and use ->kbuf
92 	 * when expecting to deal with kernel memory.
93 	 */
94 	union {
95 		void __user *buf;
96 		void *kbuf;
97 	};
98 	size_t bufsz;
99 	unsigned long mem;
100 	size_t memsz;
101 };
102 
103 #ifdef CONFIG_COMPAT
104 struct compat_kexec_segment {
105 	compat_uptr_t buf;
106 	compat_size_t bufsz;
107 	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
108 	compat_size_t memsz;
109 };
110 #endif
111 
112 #ifdef CONFIG_KEXEC_FILE
113 struct purgatory_info {
114 	/* Pointer to elf header of read only purgatory */
115 	Elf_Ehdr *ehdr;
116 
117 	/* Pointer to purgatory sechdrs which are modifiable */
118 	Elf_Shdr *sechdrs;
119 	/*
120 	 * Temporary buffer location where purgatory is loaded and relocated
121 	 * This memory can be freed post image load
122 	 */
123 	void *purgatory_buf;
124 
125 	/* Address where purgatory is finally loaded and is executed from */
126 	unsigned long purgatory_load_addr;
127 };
128 
129 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
130 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
131 			     unsigned long kernel_len, char *initrd,
132 			     unsigned long initrd_len, char *cmdline,
133 			     unsigned long cmdline_len);
134 typedef int (kexec_cleanup_t)(void *loader_data);
135 
136 #ifdef CONFIG_KEXEC_VERIFY_SIG
137 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
138 				 unsigned long kernel_len);
139 #endif
140 
141 struct kexec_file_ops {
142 	kexec_probe_t *probe;
143 	kexec_load_t *load;
144 	kexec_cleanup_t *cleanup;
145 #ifdef CONFIG_KEXEC_VERIFY_SIG
146 	kexec_verify_sig_t *verify_sig;
147 #endif
148 };
149 #endif
150 
151 struct kimage {
152 	kimage_entry_t head;
153 	kimage_entry_t *entry;
154 	kimage_entry_t *last_entry;
155 
156 	unsigned long start;
157 	struct page *control_code_page;
158 	struct page *swap_page;
159 
160 	unsigned long nr_segments;
161 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
162 
163 	struct list_head control_pages;
164 	struct list_head dest_pages;
165 	struct list_head unusable_pages;
166 
167 	/* Address of next control page to allocate for crash kernels. */
168 	unsigned long control_page;
169 
170 	/* Flags to indicate special processing */
171 	unsigned int type : 1;
172 #define KEXEC_TYPE_DEFAULT 0
173 #define KEXEC_TYPE_CRASH   1
174 	unsigned int preserve_context : 1;
175 	/* If set, we are using file mode kexec syscall */
176 	unsigned int file_mode:1;
177 
178 #ifdef ARCH_HAS_KIMAGE_ARCH
179 	struct kimage_arch arch;
180 #endif
181 
182 #ifdef CONFIG_KEXEC_FILE
183 	/* Additional fields for file based kexec syscall */
184 	void *kernel_buf;
185 	unsigned long kernel_buf_len;
186 
187 	void *initrd_buf;
188 	unsigned long initrd_buf_len;
189 
190 	char *cmdline_buf;
191 	unsigned long cmdline_buf_len;
192 
193 	/* File operations provided by image loader */
194 	struct kexec_file_ops *fops;
195 
196 	/* Image loader handling the kernel can store a pointer here */
197 	void *image_loader_data;
198 
199 	/* Information for loading purgatory */
200 	struct purgatory_info purgatory_info;
201 #endif
202 };
203 
204 /* kexec interface functions */
205 extern void machine_kexec(struct kimage *image);
206 extern int machine_kexec_prepare(struct kimage *image);
207 extern void machine_kexec_cleanup(struct kimage *image);
208 extern asmlinkage long sys_kexec_load(unsigned long entry,
209 					unsigned long nr_segments,
210 					struct kexec_segment __user *segments,
211 					unsigned long flags);
212 extern int kernel_kexec(void);
213 extern int kexec_add_buffer(struct kimage *image, char *buffer,
214 			    unsigned long bufsz, unsigned long memsz,
215 			    unsigned long buf_align, unsigned long buf_min,
216 			    unsigned long buf_max, bool top_down,
217 			    unsigned long *load_addr);
218 extern struct page *kimage_alloc_control_pages(struct kimage *image,
219 						unsigned int order);
220 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
221 				unsigned long max, int top_down,
222 				unsigned long *load_addr);
223 extern int kexec_purgatory_get_set_symbol(struct kimage *image,
224 					  const char *name, void *buf,
225 					  unsigned int size, bool get_value);
226 extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
227 					     const char *name);
228 extern void __crash_kexec(struct pt_regs *);
229 extern void crash_kexec(struct pt_regs *);
230 int kexec_should_crash(struct task_struct *);
231 void crash_save_cpu(struct pt_regs *regs, int cpu);
232 void crash_save_vmcoreinfo(void);
233 void crash_map_reserved_pages(void);
234 void crash_unmap_reserved_pages(void);
235 void arch_crash_save_vmcoreinfo(void);
236 __printf(1, 2)
237 void vmcoreinfo_append_str(const char *fmt, ...);
238 unsigned long paddr_vmcoreinfo_note(void);
239 
240 #define VMCOREINFO_OSRELEASE(value) \
241 	vmcoreinfo_append_str("OSRELEASE=%s\n", value)
242 #define VMCOREINFO_PAGESIZE(value) \
243 	vmcoreinfo_append_str("PAGESIZE=%ld\n", value)
244 #define VMCOREINFO_SYMBOL(name) \
245 	vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name)
246 #define VMCOREINFO_SIZE(name) \
247 	vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
248 			      (unsigned long)sizeof(name))
249 #define VMCOREINFO_STRUCT_SIZE(name) \
250 	vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
251 			      (unsigned long)sizeof(struct name))
252 #define VMCOREINFO_OFFSET(name, field) \
253 	vmcoreinfo_append_str("OFFSET(%s.%s)=%lu\n", #name, #field, \
254 			      (unsigned long)offsetof(struct name, field))
255 #define VMCOREINFO_LENGTH(name, value) \
256 	vmcoreinfo_append_str("LENGTH(%s)=%lu\n", #name, (unsigned long)value)
257 #define VMCOREINFO_NUMBER(name) \
258 	vmcoreinfo_append_str("NUMBER(%s)=%ld\n", #name, (long)name)
259 #define VMCOREINFO_CONFIG(name) \
260 	vmcoreinfo_append_str("CONFIG_%s=y\n", #name)
261 
262 extern struct kimage *kexec_image;
263 extern struct kimage *kexec_crash_image;
264 extern int kexec_load_disabled;
265 
266 #ifndef kexec_flush_icache_page
267 #define kexec_flush_icache_page(page)
268 #endif
269 
270 /* List of defined/legal kexec flags */
271 #ifndef CONFIG_KEXEC_JUMP
272 #define KEXEC_FLAGS    KEXEC_ON_CRASH
273 #else
274 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
275 #endif
276 
277 /* List of defined/legal kexec file flags */
278 #define KEXEC_FILE_FLAGS	(KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
279 				 KEXEC_FILE_NO_INITRAMFS)
280 
281 #define VMCOREINFO_BYTES           (4096)
282 #define VMCOREINFO_NOTE_NAME       "VMCOREINFO"
283 #define VMCOREINFO_NOTE_NAME_BYTES ALIGN(sizeof(VMCOREINFO_NOTE_NAME), 4)
284 #define VMCOREINFO_NOTE_SIZE       (KEXEC_NOTE_HEAD_BYTES*2 + VMCOREINFO_BYTES \
285 				    + VMCOREINFO_NOTE_NAME_BYTES)
286 
287 /* Location of a reserved region to hold the crash kernel.
288  */
289 extern struct resource crashk_res;
290 extern struct resource crashk_low_res;
291 typedef u32 note_buf_t[KEXEC_NOTE_BYTES/4];
292 extern note_buf_t __percpu *crash_notes;
293 extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
294 extern size_t vmcoreinfo_size;
295 extern size_t vmcoreinfo_max_size;
296 
297 /* flag to track if kexec reboot is in progress */
298 extern bool kexec_in_progress;
299 
300 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
301 		unsigned long long *crash_size, unsigned long long *crash_base);
302 int parse_crashkernel_high(char *cmdline, unsigned long long system_ram,
303 		unsigned long long *crash_size, unsigned long long *crash_base);
304 int parse_crashkernel_low(char *cmdline, unsigned long long system_ram,
305 		unsigned long long *crash_size, unsigned long long *crash_base);
306 int crash_shrink_memory(unsigned long new_size);
307 size_t crash_get_memory_size(void);
308 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
309 
310 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
311 					 unsigned long buf_len);
312 void * __weak arch_kexec_kernel_image_load(struct kimage *image);
313 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image);
314 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
315 					unsigned long buf_len);
316 int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
317 					Elf_Shdr *sechdrs, unsigned int relsec);
318 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
319 					unsigned int relsec);
320 
321 #else /* !CONFIG_KEXEC_CORE */
322 struct pt_regs;
323 struct task_struct;
324 static inline void __crash_kexec(struct pt_regs *regs) { }
325 static inline void crash_kexec(struct pt_regs *regs) { }
326 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
327 #define kexec_in_progress false
328 #endif /* CONFIG_KEXEC_CORE */
329 
330 #endif /* !defined(__ASSEBMLY__) */
331 
332 #endif /* LINUX_KEXEC_H */
333