xref: /openbmc/linux/include/linux/kexec.h (revision 10c1d542)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef LINUX_KEXEC_H
3 #define LINUX_KEXEC_H
4 
5 #define IND_DESTINATION_BIT 0
6 #define IND_INDIRECTION_BIT 1
7 #define IND_DONE_BIT        2
8 #define IND_SOURCE_BIT      3
9 
10 #define IND_DESTINATION  (1 << IND_DESTINATION_BIT)
11 #define IND_INDIRECTION  (1 << IND_INDIRECTION_BIT)
12 #define IND_DONE         (1 << IND_DONE_BIT)
13 #define IND_SOURCE       (1 << IND_SOURCE_BIT)
14 #define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE)
15 
16 #if !defined(__ASSEMBLY__)
17 
18 #include <linux/crash_core.h>
19 #include <asm/io.h>
20 
21 #include <uapi/linux/kexec.h>
22 
23 #ifdef CONFIG_KEXEC_CORE
24 #include <linux/list.h>
25 #include <linux/compat.h>
26 #include <linux/ioport.h>
27 #include <linux/module.h>
28 #include <asm/kexec.h>
29 
30 /* Verify architecture specific macros are defined */
31 
32 #ifndef KEXEC_SOURCE_MEMORY_LIMIT
33 #error KEXEC_SOURCE_MEMORY_LIMIT not defined
34 #endif
35 
36 #ifndef KEXEC_DESTINATION_MEMORY_LIMIT
37 #error KEXEC_DESTINATION_MEMORY_LIMIT not defined
38 #endif
39 
40 #ifndef KEXEC_CONTROL_MEMORY_LIMIT
41 #error KEXEC_CONTROL_MEMORY_LIMIT not defined
42 #endif
43 
44 #ifndef KEXEC_CONTROL_MEMORY_GFP
45 #define KEXEC_CONTROL_MEMORY_GFP (GFP_KERNEL | __GFP_NORETRY)
46 #endif
47 
48 #ifndef KEXEC_CONTROL_PAGE_SIZE
49 #error KEXEC_CONTROL_PAGE_SIZE not defined
50 #endif
51 
52 #ifndef KEXEC_ARCH
53 #error KEXEC_ARCH not defined
54 #endif
55 
56 #ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
57 #define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
58 #endif
59 
60 #ifndef KEXEC_CRASH_MEM_ALIGN
61 #define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
62 #endif
63 
64 #define KEXEC_CORE_NOTE_NAME	CRASH_CORE_NOTE_NAME
65 
66 /*
67  * This structure is used to hold the arguments that are used when loading
68  * kernel binaries.
69  */
70 
71 typedef unsigned long kimage_entry_t;
72 
73 struct kexec_segment {
74 	/*
75 	 * This pointer can point to user memory if kexec_load() system
76 	 * call is used or will point to kernel memory if
77 	 * kexec_file_load() system call is used.
78 	 *
79 	 * Use ->buf when expecting to deal with user memory and use ->kbuf
80 	 * when expecting to deal with kernel memory.
81 	 */
82 	union {
83 		void __user *buf;
84 		void *kbuf;
85 	};
86 	size_t bufsz;
87 	unsigned long mem;
88 	size_t memsz;
89 };
90 
91 #ifdef CONFIG_COMPAT
92 struct compat_kexec_segment {
93 	compat_uptr_t buf;
94 	compat_size_t bufsz;
95 	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
96 	compat_size_t memsz;
97 };
98 #endif
99 
100 #ifdef CONFIG_KEXEC_FILE
101 struct purgatory_info {
102 	/* Pointer to elf header of read only purgatory */
103 	Elf_Ehdr *ehdr;
104 
105 	/* Pointer to purgatory sechdrs which are modifiable */
106 	Elf_Shdr *sechdrs;
107 	/*
108 	 * Temporary buffer location where purgatory is loaded and relocated
109 	 * This memory can be freed post image load
110 	 */
111 	void *purgatory_buf;
112 
113 	/* Address where purgatory is finally loaded and is executed from */
114 	unsigned long purgatory_load_addr;
115 };
116 
117 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
118 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
119 			     unsigned long kernel_len, char *initrd,
120 			     unsigned long initrd_len, char *cmdline,
121 			     unsigned long cmdline_len);
122 typedef int (kexec_cleanup_t)(void *loader_data);
123 
124 #ifdef CONFIG_KEXEC_VERIFY_SIG
125 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
126 				 unsigned long kernel_len);
127 #endif
128 
129 struct kexec_file_ops {
130 	kexec_probe_t *probe;
131 	kexec_load_t *load;
132 	kexec_cleanup_t *cleanup;
133 #ifdef CONFIG_KEXEC_VERIFY_SIG
134 	kexec_verify_sig_t *verify_sig;
135 #endif
136 };
137 
138 /**
139  * struct kexec_buf - parameters for finding a place for a buffer in memory
140  * @image:	kexec image in which memory to search.
141  * @buffer:	Contents which will be copied to the allocated memory.
142  * @bufsz:	Size of @buffer.
143  * @mem:	On return will have address of the buffer in memory.
144  * @memsz:	Size for the buffer in memory.
145  * @buf_align:	Minimum alignment needed.
146  * @buf_min:	The buffer can't be placed below this address.
147  * @buf_max:	The buffer can't be placed above this address.
148  * @top_down:	Allocate from top of memory.
149  */
150 struct kexec_buf {
151 	struct kimage *image;
152 	void *buffer;
153 	unsigned long bufsz;
154 	unsigned long mem;
155 	unsigned long memsz;
156 	unsigned long buf_align;
157 	unsigned long buf_min;
158 	unsigned long buf_max;
159 	bool top_down;
160 };
161 
162 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
163 			       int (*func)(struct resource *, void *));
164 extern int kexec_add_buffer(struct kexec_buf *kbuf);
165 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
166 #endif /* CONFIG_KEXEC_FILE */
167 
168 struct kimage {
169 	kimage_entry_t head;
170 	kimage_entry_t *entry;
171 	kimage_entry_t *last_entry;
172 
173 	unsigned long start;
174 	struct page *control_code_page;
175 	struct page *swap_page;
176 	void *vmcoreinfo_data_copy; /* locates in the crash memory */
177 
178 	unsigned long nr_segments;
179 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
180 
181 	struct list_head control_pages;
182 	struct list_head dest_pages;
183 	struct list_head unusable_pages;
184 
185 	/* Address of next control page to allocate for crash kernels. */
186 	unsigned long control_page;
187 
188 	/* Flags to indicate special processing */
189 	unsigned int type : 1;
190 #define KEXEC_TYPE_DEFAULT 0
191 #define KEXEC_TYPE_CRASH   1
192 	unsigned int preserve_context : 1;
193 	/* If set, we are using file mode kexec syscall */
194 	unsigned int file_mode:1;
195 
196 #ifdef ARCH_HAS_KIMAGE_ARCH
197 	struct kimage_arch arch;
198 #endif
199 
200 #ifdef CONFIG_KEXEC_FILE
201 	/* Additional fields for file based kexec syscall */
202 	void *kernel_buf;
203 	unsigned long kernel_buf_len;
204 
205 	void *initrd_buf;
206 	unsigned long initrd_buf_len;
207 
208 	char *cmdline_buf;
209 	unsigned long cmdline_buf_len;
210 
211 	/* File operations provided by image loader */
212 	struct kexec_file_ops *fops;
213 
214 	/* Image loader handling the kernel can store a pointer here */
215 	void *image_loader_data;
216 
217 	/* Information for loading purgatory */
218 	struct purgatory_info purgatory_info;
219 #endif
220 };
221 
222 /* kexec interface functions */
223 extern void machine_kexec(struct kimage *image);
224 extern int machine_kexec_prepare(struct kimage *image);
225 extern void machine_kexec_cleanup(struct kimage *image);
226 extern asmlinkage long sys_kexec_load(unsigned long entry,
227 					unsigned long nr_segments,
228 					struct kexec_segment __user *segments,
229 					unsigned long flags);
230 extern int kernel_kexec(void);
231 extern struct page *kimage_alloc_control_pages(struct kimage *image,
232 						unsigned int order);
233 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
234 				unsigned long max, int top_down,
235 				unsigned long *load_addr);
236 extern int kexec_purgatory_get_set_symbol(struct kimage *image,
237 					  const char *name, void *buf,
238 					  unsigned int size, bool get_value);
239 extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
240 					     const char *name);
241 extern void __crash_kexec(struct pt_regs *);
242 extern void crash_kexec(struct pt_regs *);
243 int kexec_should_crash(struct task_struct *);
244 int kexec_crash_loaded(void);
245 void crash_save_cpu(struct pt_regs *regs, int cpu);
246 extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
247 
248 extern struct kimage *kexec_image;
249 extern struct kimage *kexec_crash_image;
250 extern int kexec_load_disabled;
251 
252 #ifndef kexec_flush_icache_page
253 #define kexec_flush_icache_page(page)
254 #endif
255 
256 /* List of defined/legal kexec flags */
257 #ifndef CONFIG_KEXEC_JUMP
258 #define KEXEC_FLAGS    KEXEC_ON_CRASH
259 #else
260 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
261 #endif
262 
263 /* List of defined/legal kexec file flags */
264 #define KEXEC_FILE_FLAGS	(KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
265 				 KEXEC_FILE_NO_INITRAMFS)
266 
267 /* Location of a reserved region to hold the crash kernel.
268  */
269 extern struct resource crashk_res;
270 extern struct resource crashk_low_res;
271 extern note_buf_t __percpu *crash_notes;
272 
273 /* flag to track if kexec reboot is in progress */
274 extern bool kexec_in_progress;
275 
276 int crash_shrink_memory(unsigned long new_size);
277 size_t crash_get_memory_size(void);
278 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
279 
280 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
281 					 unsigned long buf_len);
282 void * __weak arch_kexec_kernel_image_load(struct kimage *image);
283 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image);
284 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
285 					unsigned long buf_len);
286 int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
287 					Elf_Shdr *sechdrs, unsigned int relsec);
288 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
289 					unsigned int relsec);
290 void arch_kexec_protect_crashkres(void);
291 void arch_kexec_unprotect_crashkres(void);
292 
293 #ifndef page_to_boot_pfn
294 static inline unsigned long page_to_boot_pfn(struct page *page)
295 {
296 	return page_to_pfn(page);
297 }
298 #endif
299 
300 #ifndef boot_pfn_to_page
301 static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
302 {
303 	return pfn_to_page(boot_pfn);
304 }
305 #endif
306 
307 #ifndef phys_to_boot_phys
308 static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
309 {
310 	return phys;
311 }
312 #endif
313 
314 #ifndef boot_phys_to_phys
315 static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
316 {
317 	return boot_phys;
318 }
319 #endif
320 
321 static inline unsigned long virt_to_boot_phys(void *addr)
322 {
323 	return phys_to_boot_phys(__pa((unsigned long)addr));
324 }
325 
326 static inline void *boot_phys_to_virt(unsigned long entry)
327 {
328 	return phys_to_virt(boot_phys_to_phys(entry));
329 }
330 
331 #ifndef arch_kexec_post_alloc_pages
332 static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
333 #endif
334 
335 #ifndef arch_kexec_pre_free_pages
336 static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
337 #endif
338 
339 #else /* !CONFIG_KEXEC_CORE */
340 struct pt_regs;
341 struct task_struct;
342 static inline void __crash_kexec(struct pt_regs *regs) { }
343 static inline void crash_kexec(struct pt_regs *regs) { }
344 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
345 static inline int kexec_crash_loaded(void) { return 0; }
346 #define kexec_in_progress false
347 #endif /* CONFIG_KEXEC_CORE */
348 
349 #endif /* !defined(__ASSEBMLY__) */
350 
351 #endif /* LINUX_KEXEC_H */
352