xref: /linux-6.15/include/linux/kernel.h (revision 18c99362)
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 USHORT_MAX	((u16)(~0U))
24 #define SHORT_MAX	((s16)(USHORT_MAX>>1))
25 #define SHORT_MIN	(-SHORT_MAX - 1)
26 #define INT_MAX		((int)(~0U>>1))
27 #define INT_MIN		(-INT_MAX - 1)
28 #define UINT_MAX	(~0U)
29 #define LONG_MAX	((long)(~0UL>>1))
30 #define LONG_MIN	(-LONG_MAX - 1)
31 #define ULONG_MAX	(~0UL)
32 #define LLONG_MAX	((long long)(~0ULL>>1))
33 #define LLONG_MIN	(-LLONG_MAX - 1)
34 #define ULLONG_MAX	(~0ULL)
35 
36 #define STACK_MAGIC	0xdeadbeef
37 
38 #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
39 #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
40 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
41 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
42 
43 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
44 
45 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
46 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
47 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
48 
49 #define _RET_IP_		(unsigned long)__builtin_return_address(0)
50 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
51 
52 #ifdef CONFIG_LBD
53 # include <asm/div64.h>
54 # define sector_div(a, b) do_div(a, b)
55 #else
56 # define sector_div(n, b)( \
57 { \
58 	int _res; \
59 	_res = (n) % (b); \
60 	(n) /= (b); \
61 	_res; \
62 } \
63 )
64 #endif
65 
66 /**
67  * upper_32_bits - return bits 32-63 of a number
68  * @n: the number we're accessing
69  *
70  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
71  * the "right shift count >= width of type" warning when that quantity is
72  * 32-bits.
73  */
74 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
75 
76 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
77 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
78 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
79 #define	KERN_ERR	"<3>"	/* error conditions			*/
80 #define	KERN_WARNING	"<4>"	/* warning conditions			*/
81 #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
82 #define	KERN_INFO	"<6>"	/* informational			*/
83 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
84 
85 /*
86  * Annotation for a "continued" line of log printout (only done after a
87  * line that had no enclosing \n). Only to be used by core/arch code
88  * during early bootup (a continued line is not SMP-safe otherwise).
89  */
90 #define	KERN_CONT	""
91 
92 extern int console_printk[];
93 
94 #define console_loglevel (console_printk[0])
95 #define default_message_loglevel (console_printk[1])
96 #define minimum_console_loglevel (console_printk[2])
97 #define default_console_loglevel (console_printk[3])
98 
99 struct completion;
100 struct pt_regs;
101 struct user;
102 
103 /**
104  * might_sleep - annotation for functions that can sleep
105  *
106  * this macro will print a stack trace if it is executed in an atomic
107  * context (spinlock, irq-handler, ...).
108  *
109  * This is a useful debugging help to be able to catch problems early and not
110  * be bitten later when the calling function happens to sleep when it is not
111  * supposed to.
112  */
113 #ifdef CONFIG_PREEMPT_VOLUNTARY
114 extern int _cond_resched(void);
115 # define might_resched() _cond_resched()
116 #else
117 # define might_resched() do { } while (0)
118 #endif
119 
120 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
121   void __might_sleep(char *file, int line);
122 # define might_sleep() \
123 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
124 #else
125 # define might_sleep() do { might_resched(); } while (0)
126 #endif
127 
128 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
129 
130 #define abs(x) ({				\
131 		int __x = (x);			\
132 		(__x < 0) ? -__x : __x;		\
133 	})
134 
135 extern struct atomic_notifier_head panic_notifier_list;
136 extern long (*panic_blink)(long time);
137 NORET_TYPE void panic(const char * fmt, ...)
138 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
139 extern void oops_enter(void);
140 extern void oops_exit(void);
141 extern int oops_may_print(void);
142 NORET_TYPE void do_exit(long error_code)
143 	ATTRIB_NORET;
144 NORET_TYPE void complete_and_exit(struct completion *, long)
145 	ATTRIB_NORET;
146 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
147 extern long simple_strtol(const char *,char **,unsigned int);
148 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
149 extern long long simple_strtoll(const char *,char **,unsigned int);
150 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
151 extern int strict_strtol(const char *, unsigned int, long *);
152 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
153 extern int strict_strtoll(const char *, unsigned int, long long *);
154 extern int sprintf(char * buf, const char * fmt, ...)
155 	__attribute__ ((format (printf, 2, 3)));
156 extern int vsprintf(char *buf, const char *, va_list)
157 	__attribute__ ((format (printf, 2, 0)));
158 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
159 	__attribute__ ((format (printf, 3, 4)));
160 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
161 	__attribute__ ((format (printf, 3, 0)));
162 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
163 	__attribute__ ((format (printf, 3, 4)));
164 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
165 	__attribute__ ((format (printf, 3, 0)));
166 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
167 	__attribute__ ((format (printf, 2, 3)));
168 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
169 
170 extern int sscanf(const char *, const char *, ...)
171 	__attribute__ ((format (scanf, 2, 3)));
172 extern int vsscanf(const char *, const char *, va_list)
173 	__attribute__ ((format (scanf, 2, 0)));
174 
175 extern int get_option(char **str, int *pint);
176 extern char *get_options(const char *str, int nints, int *ints);
177 extern unsigned long long memparse(char *ptr, char **retptr);
178 
179 extern int core_kernel_text(unsigned long addr);
180 extern int __kernel_text_address(unsigned long addr);
181 extern int kernel_text_address(unsigned long addr);
182 struct pid;
183 extern struct pid *session_of_pgrp(struct pid *pgrp);
184 
185 #ifdef CONFIG_PRINTK
186 asmlinkage int vprintk(const char *fmt, va_list args)
187 	__attribute__ ((format (printf, 1, 0)));
188 asmlinkage int printk(const char * fmt, ...)
189 	__attribute__ ((format (printf, 1, 2))) __cold;
190 
191 extern int printk_ratelimit_jiffies;
192 extern int printk_ratelimit_burst;
193 extern int printk_ratelimit(void);
194 extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst);
195 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
196 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
197 				   unsigned int interval_msec);
198 #else
199 static inline int vprintk(const char *s, va_list args)
200 	__attribute__ ((format (printf, 1, 0)));
201 static inline int vprintk(const char *s, va_list args) { return 0; }
202 static inline int printk(const char *s, ...)
203 	__attribute__ ((format (printf, 1, 2)));
204 static inline int __cold printk(const char *s, ...) { return 0; }
205 static inline int printk_ratelimit(void) { return 0; }
206 static inline int __printk_ratelimit(int ratelimit_jiffies, \
207 				     int ratelimit_burst) { return 0; }
208 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
209 					  unsigned int interval_msec)	\
210 		{ return false; }
211 #endif
212 
213 extern void asmlinkage __attribute__((format(printf, 1, 2)))
214 	early_printk(const char *fmt, ...);
215 
216 unsigned long int_sqrt(unsigned long);
217 
218 static inline void console_silent(void)
219 {
220 	console_loglevel = 0;
221 }
222 
223 static inline void console_verbose(void)
224 {
225 	if (console_loglevel)
226 		console_loglevel = 15;
227 }
228 
229 extern void bust_spinlocks(int yes);
230 extern void wake_up_klogd(void);
231 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
232 extern int panic_timeout;
233 extern int panic_on_oops;
234 extern int panic_on_unrecovered_nmi;
235 extern int tainted;
236 extern const char *print_tainted(void);
237 extern void add_taint(unsigned);
238 extern int root_mountflags;
239 
240 /* Values used for system_state */
241 extern enum system_states {
242 	SYSTEM_BOOTING,
243 	SYSTEM_RUNNING,
244 	SYSTEM_HALT,
245 	SYSTEM_POWER_OFF,
246 	SYSTEM_RESTART,
247 	SYSTEM_SUSPEND_DISK,
248 } system_state;
249 
250 #define TAINT_PROPRIETARY_MODULE	(1<<0)
251 #define TAINT_FORCED_MODULE		(1<<1)
252 #define TAINT_UNSAFE_SMP		(1<<2)
253 #define TAINT_FORCED_RMMOD		(1<<3)
254 #define TAINT_MACHINE_CHECK		(1<<4)
255 #define TAINT_BAD_PAGE			(1<<5)
256 #define TAINT_USER			(1<<6)
257 #define TAINT_DIE			(1<<7)
258 #define TAINT_OVERRIDDEN_ACPI_TABLE	(1<<8)
259 #define TAINT_WARN			(1<<9)
260 
261 extern void dump_stack(void) __cold;
262 
263 enum {
264 	DUMP_PREFIX_NONE,
265 	DUMP_PREFIX_ADDRESS,
266 	DUMP_PREFIX_OFFSET
267 };
268 extern void hex_dump_to_buffer(const void *buf, size_t len,
269 				int rowsize, int groupsize,
270 				char *linebuf, size_t linebuflen, bool ascii);
271 extern void print_hex_dump(const char *level, const char *prefix_str,
272 				int prefix_type, int rowsize, int groupsize,
273 				const void *buf, size_t len, bool ascii);
274 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
275 			const void *buf, size_t len);
276 
277 extern const char hex_asc[];
278 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
279 #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
280 
281 static inline char *pack_hex_byte(char *buf, u8 byte)
282 {
283 	*buf++ = hex_asc_hi(byte);
284 	*buf++ = hex_asc_lo(byte);
285 	return buf;
286 }
287 
288 #define pr_emerg(fmt, arg...) \
289 	printk(KERN_EMERG fmt, ##arg)
290 #define pr_alert(fmt, arg...) \
291 	printk(KERN_ALERT fmt, ##arg)
292 #define pr_crit(fmt, arg...) \
293 	printk(KERN_CRIT fmt, ##arg)
294 #define pr_err(fmt, arg...) \
295 	printk(KERN_ERR fmt, ##arg)
296 #define pr_warning(fmt, arg...) \
297 	printk(KERN_WARNING fmt, ##arg)
298 #define pr_notice(fmt, arg...) \
299 	printk(KERN_NOTICE fmt, ##arg)
300 #define pr_info(fmt, arg...) \
301 	printk(KERN_INFO fmt, ##arg)
302 
303 #ifdef DEBUG
304 /* If you are writing a driver, please use dev_dbg instead */
305 #define pr_debug(fmt, arg...) \
306 	printk(KERN_DEBUG fmt, ##arg)
307 #else
308 #define pr_debug(fmt, arg...) \
309 	({ if (0) printk(KERN_DEBUG fmt, ##arg); 0; })
310 #endif
311 
312 /*
313  *      Display an IP address in readable format.
314  */
315 
316 #define NIPQUAD(addr) \
317 	((unsigned char *)&addr)[0], \
318 	((unsigned char *)&addr)[1], \
319 	((unsigned char *)&addr)[2], \
320 	((unsigned char *)&addr)[3]
321 #define NIPQUAD_FMT "%u.%u.%u.%u"
322 
323 #define NIP6(addr) \
324 	ntohs((addr).s6_addr16[0]), \
325 	ntohs((addr).s6_addr16[1]), \
326 	ntohs((addr).s6_addr16[2]), \
327 	ntohs((addr).s6_addr16[3]), \
328 	ntohs((addr).s6_addr16[4]), \
329 	ntohs((addr).s6_addr16[5]), \
330 	ntohs((addr).s6_addr16[6]), \
331 	ntohs((addr).s6_addr16[7])
332 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
333 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
334 
335 #if defined(__LITTLE_ENDIAN)
336 #define HIPQUAD(addr) \
337 	((unsigned char *)&addr)[3], \
338 	((unsigned char *)&addr)[2], \
339 	((unsigned char *)&addr)[1], \
340 	((unsigned char *)&addr)[0]
341 #elif defined(__BIG_ENDIAN)
342 #define HIPQUAD	NIPQUAD
343 #else
344 #error "Please fix asm/byteorder.h"
345 #endif /* __LITTLE_ENDIAN */
346 
347 /*
348  * min()/max()/clamp() macros that also do
349  * strict type-checking.. See the
350  * "unnecessary" pointer comparison.
351  */
352 #define min(x, y) ({				\
353 	typeof(x) _min1 = (x);			\
354 	typeof(y) _min2 = (y);			\
355 	(void) (&_min1 == &_min2);		\
356 	_min1 < _min2 ? _min1 : _min2; })
357 
358 #define max(x, y) ({				\
359 	typeof(x) _max1 = (x);			\
360 	typeof(y) _max2 = (y);			\
361 	(void) (&_max1 == &_max2);		\
362 	_max1 > _max2 ? _max1 : _max2; })
363 
364 /**
365  * clamp - return a value clamped to a given range with strict typechecking
366  * @val: current value
367  * @min: minimum allowable value
368  * @max: maximum allowable value
369  *
370  * This macro does strict typechecking of min/max to make sure they are of the
371  * same type as val.  See the unnecessary pointer comparisons.
372  */
373 #define clamp(val, min, max) ({			\
374 	typeof(val) __val = (val);		\
375 	typeof(min) __min = (min);		\
376 	typeof(max) __max = (max);		\
377 	(void) (&__val == &__min);		\
378 	(void) (&__val == &__max);		\
379 	__val = __val < __min ? __min: __val;	\
380 	__val > __max ? __max: __val; })
381 
382 /*
383  * ..and if you can't take the strict
384  * types, you can specify one yourself.
385  *
386  * Or not use min/max/clamp at all, of course.
387  */
388 #define min_t(type, x, y) ({			\
389 	type __min1 = (x);			\
390 	type __min2 = (y);			\
391 	__min1 < __min2 ? __min1: __min2; })
392 
393 #define max_t(type, x, y) ({			\
394 	type __max1 = (x);			\
395 	type __max2 = (y);			\
396 	__max1 > __max2 ? __max1: __max2; })
397 
398 /**
399  * clamp_t - return a value clamped to a given range using a given type
400  * @type: the type of variable to use
401  * @val: current value
402  * @min: minimum allowable value
403  * @max: maximum allowable value
404  *
405  * This macro does no typechecking and uses temporary variables of type
406  * 'type' to make all the comparisons.
407  */
408 #define clamp_t(type, val, min, max) ({		\
409 	type __val = (val);			\
410 	type __min = (min);			\
411 	type __max = (max);			\
412 	__val = __val < __min ? __min: __val;	\
413 	__val > __max ? __max: __val; })
414 
415 /**
416  * clamp_val - return a value clamped to a given range using val's type
417  * @val: current value
418  * @min: minimum allowable value
419  * @max: maximum allowable value
420  *
421  * This macro does no typechecking and uses temporary variables of whatever
422  * type the input argument 'val' is.  This is useful when val is an unsigned
423  * type and min and max are literals that will otherwise be assigned a signed
424  * integer type.
425  */
426 #define clamp_val(val, min, max) ({		\
427 	typeof(val) __val = (val);		\
428 	typeof(val) __min = (min);		\
429 	typeof(val) __max = (max);		\
430 	__val = __val < __min ? __min: __val;	\
431 	__val > __max ? __max: __val; })
432 
433 /**
434  * container_of - cast a member of a structure out to the containing structure
435  * @ptr:	the pointer to the member.
436  * @type:	the type of the container struct this is embedded in.
437  * @member:	the name of the member within the struct.
438  *
439  */
440 #define container_of(ptr, type, member) ({			\
441 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
442 	(type *)( (char *)__mptr - offsetof(type,member) );})
443 
444 /*
445  * Check at compile time that something is of a particular type.
446  * Always evaluates to 1 so you may use it easily in comparisons.
447  */
448 #define typecheck(type,x) \
449 ({	type __dummy; \
450 	typeof(x) __dummy2; \
451 	(void)(&__dummy == &__dummy2); \
452 	1; \
453 })
454 
455 /*
456  * Check at compile time that 'function' is a certain type, or is a pointer
457  * to that type (needs to use typedef for the function type.)
458  */
459 #define typecheck_fn(type,function) \
460 ({	typeof(type) __tmp = function; \
461 	(void)__tmp; \
462 })
463 
464 struct sysinfo;
465 extern int do_sysinfo(struct sysinfo *info);
466 
467 #endif /* __KERNEL__ */
468 
469 #define SI_LOAD_SHIFT	16
470 struct sysinfo {
471 	long uptime;			/* Seconds since boot */
472 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
473 	unsigned long totalram;		/* Total usable main memory size */
474 	unsigned long freeram;		/* Available memory size */
475 	unsigned long sharedram;	/* Amount of shared memory */
476 	unsigned long bufferram;	/* Memory used by buffers */
477 	unsigned long totalswap;	/* Total swap space size */
478 	unsigned long freeswap;		/* swap space still available */
479 	unsigned short procs;		/* Number of current processes */
480 	unsigned short pad;		/* explicit padding for m68k */
481 	unsigned long totalhigh;	/* Total high memory size */
482 	unsigned long freehigh;		/* Available high memory size */
483 	unsigned int mem_unit;		/* Memory unit size in bytes */
484 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
485 };
486 
487 /* Force a compilation error if condition is true */
488 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
489 
490 /* Force a compilation error if condition is true, but also produce a
491    result (of value 0 and type size_t), so the expression can be used
492    e.g. in a structure initializer (or where-ever else comma expressions
493    aren't permitted). */
494 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
495 
496 /* Trap pasters of __FUNCTION__ at compile-time */
497 #define __FUNCTION__ (__func__)
498 
499 /* This helps us to avoid #ifdef CONFIG_NUMA */
500 #ifdef CONFIG_NUMA
501 #define NUMA_BUILD 1
502 #else
503 #define NUMA_BUILD 0
504 #endif
505 
506 #endif
507