xref: /linux-6.15/include/linux/kernel.h (revision a0f97e06)
1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
3 
4 /*
5  * 'kernel.h' contains some often-used function prototypes etc
6  */
7 
8 #ifdef __KERNEL__
9 
10 #include <stdarg.h>
11 #include <linux/linkage.h>
12 #include <linux/stddef.h>
13 #include <linux/types.h>
14 #include <linux/compiler.h>
15 #include <linux/bitops.h>
16 #include <linux/log2.h>
17 #include <asm/byteorder.h>
18 #include <asm/bug.h>
19 
20 extern const char linux_banner[];
21 extern const char linux_proc_banner[];
22 
23 #define INT_MAX		((int)(~0U>>1))
24 #define INT_MIN		(-INT_MAX - 1)
25 #define UINT_MAX	(~0U)
26 #define LONG_MAX	((long)(~0UL>>1))
27 #define LONG_MIN	(-LONG_MAX - 1)
28 #define ULONG_MAX	(~0UL)
29 #define LLONG_MAX	((long long)(~0ULL>>1))
30 #define LLONG_MIN	(-LLONG_MAX - 1)
31 #define ULLONG_MAX	(~0ULL)
32 
33 #define STACK_MAGIC	0xdeadbeef
34 
35 #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
36 #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
37 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
38 
39 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
40 
41 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
42 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
43 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
44 
45 /**
46  * upper_32_bits - return bits 32-63 of a number
47  * @n: the number we're accessing
48  *
49  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
50  * the "right shift count >= width of type" warning when that quantity is
51  * 32-bits.
52  */
53 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
54 
55 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
56 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
57 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
58 #define	KERN_ERR	"<3>"	/* error conditions			*/
59 #define	KERN_WARNING	"<4>"	/* warning conditions			*/
60 #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
61 #define	KERN_INFO	"<6>"	/* informational			*/
62 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
63 
64 extern int console_printk[];
65 
66 #define console_loglevel (console_printk[0])
67 #define default_message_loglevel (console_printk[1])
68 #define minimum_console_loglevel (console_printk[2])
69 #define default_console_loglevel (console_printk[3])
70 
71 struct completion;
72 struct pt_regs;
73 struct user;
74 
75 /**
76  * might_sleep - annotation for functions that can sleep
77  *
78  * this macro will print a stack trace if it is executed in an atomic
79  * context (spinlock, irq-handler, ...).
80  *
81  * This is a useful debugging help to be able to catch problems early and not
82  * be bitten later when the calling function happens to sleep when it is not
83  * supposed to.
84  */
85 #ifdef CONFIG_PREEMPT_VOLUNTARY
86 extern int cond_resched(void);
87 # define might_resched() cond_resched()
88 #else
89 # define might_resched() do { } while (0)
90 #endif
91 
92 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
93   void __might_sleep(char *file, int line);
94 # define might_sleep() \
95 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
96 #else
97 # define might_sleep() do { might_resched(); } while (0)
98 #endif
99 
100 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
101 
102 #define abs(x) ({				\
103 		int __x = (x);			\
104 		(__x < 0) ? -__x : __x;		\
105 	})
106 
107 extern struct atomic_notifier_head panic_notifier_list;
108 extern long (*panic_blink)(long time);
109 NORET_TYPE void panic(const char * fmt, ...)
110 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
111 extern void oops_enter(void);
112 extern void oops_exit(void);
113 extern int oops_may_print(void);
114 fastcall NORET_TYPE void do_exit(long error_code)
115 	ATTRIB_NORET;
116 NORET_TYPE void complete_and_exit(struct completion *, long)
117 	ATTRIB_NORET;
118 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
119 extern long simple_strtol(const char *,char **,unsigned int);
120 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
121 extern long long simple_strtoll(const char *,char **,unsigned int);
122 extern int sprintf(char * buf, const char * fmt, ...)
123 	__attribute__ ((format (printf, 2, 3)));
124 extern int vsprintf(char *buf, const char *, va_list)
125 	__attribute__ ((format (printf, 2, 0)));
126 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
127 	__attribute__ ((format (printf, 3, 4)));
128 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
129 	__attribute__ ((format (printf, 3, 0)));
130 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
131 	__attribute__ ((format (printf, 3, 4)));
132 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
133 	__attribute__ ((format (printf, 3, 0)));
134 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
135 	__attribute__ ((format (printf, 2, 3)));
136 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
137 
138 extern int sscanf(const char *, const char *, ...)
139 	__attribute__ ((format (scanf, 2, 3)));
140 extern int vsscanf(const char *, const char *, va_list)
141 	__attribute__ ((format (scanf, 2, 0)));
142 
143 extern int get_option(char **str, int *pint);
144 extern char *get_options(const char *str, int nints, int *ints);
145 extern unsigned long long memparse(char *ptr, char **retptr);
146 
147 extern int core_kernel_text(unsigned long addr);
148 extern int __kernel_text_address(unsigned long addr);
149 extern int kernel_text_address(unsigned long addr);
150 struct pid;
151 extern struct pid *session_of_pgrp(struct pid *pgrp);
152 
153 extern void dump_thread(struct pt_regs *regs, struct user *dump);
154 
155 #ifdef CONFIG_PRINTK
156 asmlinkage int vprintk(const char *fmt, va_list args)
157 	__attribute__ ((format (printf, 1, 0)));
158 asmlinkage int printk(const char * fmt, ...)
159 	__attribute__ ((format (printf, 1, 2))) __cold;
160 #else
161 static inline int vprintk(const char *s, va_list args)
162 	__attribute__ ((format (printf, 1, 0)));
163 static inline int vprintk(const char *s, va_list args) { return 0; }
164 static inline int printk(const char *s, ...)
165 	__attribute__ ((format (printf, 1, 2)));
166 static inline int __cold printk(const char *s, ...) { return 0; }
167 #endif
168 
169 unsigned long int_sqrt(unsigned long);
170 
171 extern int printk_ratelimit(void);
172 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
173 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
174 				unsigned int interval_msec);
175 
176 static inline void console_silent(void)
177 {
178 	console_loglevel = 0;
179 }
180 
181 static inline void console_verbose(void)
182 {
183 	if (console_loglevel)
184 		console_loglevel = 15;
185 }
186 
187 extern void bust_spinlocks(int yes);
188 extern void wake_up_klogd(void);
189 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
190 extern int panic_timeout;
191 extern int panic_on_oops;
192 extern int panic_on_unrecovered_nmi;
193 extern int tainted;
194 extern const char *print_tainted(void);
195 extern void add_taint(unsigned);
196 
197 /* Values used for system_state */
198 extern enum system_states {
199 	SYSTEM_BOOTING,
200 	SYSTEM_RUNNING,
201 	SYSTEM_HALT,
202 	SYSTEM_POWER_OFF,
203 	SYSTEM_RESTART,
204 	SYSTEM_SUSPEND_DISK,
205 } system_state;
206 
207 #define TAINT_PROPRIETARY_MODULE	(1<<0)
208 #define TAINT_FORCED_MODULE		(1<<1)
209 #define TAINT_UNSAFE_SMP		(1<<2)
210 #define TAINT_FORCED_RMMOD		(1<<3)
211 #define TAINT_MACHINE_CHECK		(1<<4)
212 #define TAINT_BAD_PAGE			(1<<5)
213 #define TAINT_USER			(1<<6)
214 #define TAINT_DIE			(1<<7)
215 
216 extern void dump_stack(void) __cold;
217 
218 enum {
219 	DUMP_PREFIX_NONE,
220 	DUMP_PREFIX_ADDRESS,
221 	DUMP_PREFIX_OFFSET
222 };
223 extern void hex_dump_to_buffer(const void *buf, size_t len,
224 				int rowsize, int groupsize,
225 				char *linebuf, size_t linebuflen, bool ascii);
226 extern void print_hex_dump(const char *level, const char *prefix_str,
227 				int prefix_type, int rowsize, int groupsize,
228 				const void *buf, size_t len, bool ascii);
229 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
230 			const void *buf, size_t len);
231 #define hex_asc(x)	"0123456789abcdef"[x]
232 
233 #ifdef DEBUG
234 /* If you are writing a driver, please use dev_dbg instead */
235 #define pr_debug(fmt,arg...) \
236 	printk(KERN_DEBUG fmt,##arg)
237 #else
238 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
239 {
240 	return 0;
241 }
242 #endif
243 
244 #define pr_info(fmt,arg...) \
245 	printk(KERN_INFO fmt,##arg)
246 
247 /*
248  *      Display an IP address in readable format.
249  */
250 
251 #define NIPQUAD(addr) \
252 	((unsigned char *)&addr)[0], \
253 	((unsigned char *)&addr)[1], \
254 	((unsigned char *)&addr)[2], \
255 	((unsigned char *)&addr)[3]
256 #define NIPQUAD_FMT "%u.%u.%u.%u"
257 
258 #define NIP6(addr) \
259 	ntohs((addr).s6_addr16[0]), \
260 	ntohs((addr).s6_addr16[1]), \
261 	ntohs((addr).s6_addr16[2]), \
262 	ntohs((addr).s6_addr16[3]), \
263 	ntohs((addr).s6_addr16[4]), \
264 	ntohs((addr).s6_addr16[5]), \
265 	ntohs((addr).s6_addr16[6]), \
266 	ntohs((addr).s6_addr16[7])
267 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
268 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
269 
270 #if defined(__LITTLE_ENDIAN)
271 #define HIPQUAD(addr) \
272 	((unsigned char *)&addr)[3], \
273 	((unsigned char *)&addr)[2], \
274 	((unsigned char *)&addr)[1], \
275 	((unsigned char *)&addr)[0]
276 #elif defined(__BIG_ENDIAN)
277 #define HIPQUAD	NIPQUAD
278 #else
279 #error "Please fix asm/byteorder.h"
280 #endif /* __LITTLE_ENDIAN */
281 
282 /*
283  * min()/max() macros that also do
284  * strict type-checking.. See the
285  * "unnecessary" pointer comparison.
286  */
287 #define min(x,y) ({ \
288 	typeof(x) _x = (x);	\
289 	typeof(y) _y = (y);	\
290 	(void) (&_x == &_y);		\
291 	_x < _y ? _x : _y; })
292 
293 #define max(x,y) ({ \
294 	typeof(x) _x = (x);	\
295 	typeof(y) _y = (y);	\
296 	(void) (&_x == &_y);		\
297 	_x > _y ? _x : _y; })
298 
299 /*
300  * ..and if you can't take the strict
301  * types, you can specify one yourself.
302  *
303  * Or not use min/max at all, of course.
304  */
305 #define min_t(type,x,y) \
306 	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
307 #define max_t(type,x,y) \
308 	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
309 
310 
311 /**
312  * container_of - cast a member of a structure out to the containing structure
313  * @ptr:	the pointer to the member.
314  * @type:	the type of the container struct this is embedded in.
315  * @member:	the name of the member within the struct.
316  *
317  */
318 #define container_of(ptr, type, member) ({			\
319 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
320 	(type *)( (char *)__mptr - offsetof(type,member) );})
321 
322 /*
323  * Check at compile time that something is of a particular type.
324  * Always evaluates to 1 so you may use it easily in comparisons.
325  */
326 #define typecheck(type,x) \
327 ({	type __dummy; \
328 	typeof(x) __dummy2; \
329 	(void)(&__dummy == &__dummy2); \
330 	1; \
331 })
332 
333 /*
334  * Check at compile time that 'function' is a certain type, or is a pointer
335  * to that type (needs to use typedef for the function type.)
336  */
337 #define typecheck_fn(type,function) \
338 ({	typeof(type) __tmp = function; \
339 	(void)__tmp; \
340 })
341 
342 struct sysinfo;
343 extern int do_sysinfo(struct sysinfo *info);
344 
345 #endif /* __KERNEL__ */
346 
347 #define SI_LOAD_SHIFT	16
348 struct sysinfo {
349 	long uptime;			/* Seconds since boot */
350 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
351 	unsigned long totalram;		/* Total usable main memory size */
352 	unsigned long freeram;		/* Available memory size */
353 	unsigned long sharedram;	/* Amount of shared memory */
354 	unsigned long bufferram;	/* Memory used by buffers */
355 	unsigned long totalswap;	/* Total swap space size */
356 	unsigned long freeswap;		/* swap space still available */
357 	unsigned short procs;		/* Number of current processes */
358 	unsigned short pad;		/* explicit padding for m68k */
359 	unsigned long totalhigh;	/* Total high memory size */
360 	unsigned long freehigh;		/* Available high memory size */
361 	unsigned int mem_unit;		/* Memory unit size in bytes */
362 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
363 };
364 
365 /* Force a compilation error if condition is true */
366 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
367 
368 /* Force a compilation error if condition is true, but also produce a
369    result (of value 0 and type size_t), so the expression can be used
370    e.g. in a structure initializer (or where-ever else comma expressions
371    aren't permitted). */
372 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
373 
374 /* Trap pasters of __FUNCTION__ at compile-time */
375 #define __FUNCTION__ (__func__)
376 
377 /* This helps us to avoid #ifdef CONFIG_NUMA */
378 #ifdef CONFIG_NUMA
379 #define NUMA_BUILD 1
380 #else
381 #define NUMA_BUILD 0
382 #endif
383 
384 #endif
385