xref: /linux-6.15/include/linux/kernel.h (revision d289bf7b)
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 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
39 
40 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
41 
42 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
43 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
44 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
45 
46 #ifdef CONFIG_LBD
47 # include <asm/div64.h>
48 # define sector_div(a, b) do_div(a, b)
49 #else
50 # define sector_div(n, b)( \
51 { \
52 	int _res; \
53 	_res = (n) % (b); \
54 	(n) /= (b); \
55 	_res; \
56 } \
57 )
58 #endif
59 
60 /**
61  * upper_32_bits - return bits 32-63 of a number
62  * @n: the number we're accessing
63  *
64  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
65  * the "right shift count >= width of type" warning when that quantity is
66  * 32-bits.
67  */
68 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
69 
70 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
71 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
72 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
73 #define	KERN_ERR	"<3>"	/* error conditions			*/
74 #define	KERN_WARNING	"<4>"	/* warning conditions			*/
75 #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
76 #define	KERN_INFO	"<6>"	/* informational			*/
77 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
78 
79 /*
80  * Annotation for a "continued" line of log printout (only done after a
81  * line that had no enclosing \n). Only to be used by core/arch code
82  * during early bootup (a continued line is not SMP-safe otherwise).
83  */
84 #define	KERN_CONT	""
85 
86 extern int console_printk[];
87 
88 #define console_loglevel (console_printk[0])
89 #define default_message_loglevel (console_printk[1])
90 #define minimum_console_loglevel (console_printk[2])
91 #define default_console_loglevel (console_printk[3])
92 
93 struct completion;
94 struct pt_regs;
95 struct user;
96 
97 /**
98  * might_sleep - annotation for functions that can sleep
99  *
100  * this macro will print a stack trace if it is executed in an atomic
101  * context (spinlock, irq-handler, ...).
102  *
103  * This is a useful debugging help to be able to catch problems early and not
104  * be bitten later when the calling function happens to sleep when it is not
105  * supposed to.
106  */
107 #ifdef CONFIG_PREEMPT_VOLUNTARY
108 extern int _cond_resched(void);
109 # define might_resched() _cond_resched()
110 #else
111 # define might_resched() do { } while (0)
112 #endif
113 
114 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
115   void __might_sleep(char *file, int line);
116 # define might_sleep() \
117 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
118 #else
119 # define might_sleep() do { might_resched(); } while (0)
120 #endif
121 
122 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
123 
124 #define abs(x) ({				\
125 		int __x = (x);			\
126 		(__x < 0) ? -__x : __x;		\
127 	})
128 
129 extern struct atomic_notifier_head panic_notifier_list;
130 extern long (*panic_blink)(long time);
131 NORET_TYPE void panic(const char * fmt, ...)
132 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
133 extern void oops_enter(void);
134 extern void oops_exit(void);
135 extern int oops_may_print(void);
136 NORET_TYPE void do_exit(long error_code)
137 	ATTRIB_NORET;
138 NORET_TYPE void complete_and_exit(struct completion *, long)
139 	ATTRIB_NORET;
140 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
141 extern long simple_strtol(const char *,char **,unsigned int);
142 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
143 extern long long simple_strtoll(const char *,char **,unsigned int);
144 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
145 extern int strict_strtol(const char *, unsigned int, long *);
146 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
147 extern int strict_strtoll(const char *, unsigned int, long long *);
148 extern int sprintf(char * buf, const char * fmt, ...)
149 	__attribute__ ((format (printf, 2, 3)));
150 extern int vsprintf(char *buf, const char *, va_list)
151 	__attribute__ ((format (printf, 2, 0)));
152 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
153 	__attribute__ ((format (printf, 3, 4)));
154 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
155 	__attribute__ ((format (printf, 3, 0)));
156 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
157 	__attribute__ ((format (printf, 3, 4)));
158 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
159 	__attribute__ ((format (printf, 3, 0)));
160 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
161 	__attribute__ ((format (printf, 2, 3)));
162 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
163 
164 extern int sscanf(const char *, const char *, ...)
165 	__attribute__ ((format (scanf, 2, 3)));
166 extern int vsscanf(const char *, const char *, va_list)
167 	__attribute__ ((format (scanf, 2, 0)));
168 
169 extern int get_option(char **str, int *pint);
170 extern char *get_options(const char *str, int nints, int *ints);
171 extern unsigned long long memparse(char *ptr, char **retptr);
172 
173 extern int core_kernel_text(unsigned long addr);
174 extern int __kernel_text_address(unsigned long addr);
175 extern int kernel_text_address(unsigned long addr);
176 struct pid;
177 extern struct pid *session_of_pgrp(struct pid *pgrp);
178 
179 #ifdef CONFIG_PRINTK
180 asmlinkage int vprintk(const char *fmt, va_list args)
181 	__attribute__ ((format (printf, 1, 0)));
182 asmlinkage int printk(const char * fmt, ...)
183 	__attribute__ ((format (printf, 1, 2))) __cold;
184 extern int log_buf_get_len(void);
185 extern int log_buf_read(int idx);
186 extern int log_buf_copy(char *dest, int idx, int len);
187 
188 extern int printk_ratelimit_jiffies;
189 extern int printk_ratelimit_burst;
190 extern int printk_ratelimit(void);
191 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
192 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
193 				   unsigned int interval_msec);
194 #else
195 static inline int vprintk(const char *s, va_list args)
196 	__attribute__ ((format (printf, 1, 0)));
197 static inline int vprintk(const char *s, va_list args) { return 0; }
198 static inline int printk(const char *s, ...)
199 	__attribute__ ((format (printf, 1, 2)));
200 static inline int __cold printk(const char *s, ...) { return 0; }
201 static inline int log_buf_get_len(void) { return 0; }
202 static inline int log_buf_read(int idx) { return 0; }
203 static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }
204 static inline int printk_ratelimit(void) { return 0; }
205 static inline int __printk_ratelimit(int ratelimit_jiffies, \
206 				     int ratelimit_burst) { return 0; }
207 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
208 					  unsigned int interval_msec)	\
209 		{ return false; }
210 #endif
211 
212 extern void __attribute__((format(printf, 1, 2)))
213 	early_printk(const char *fmt, ...);
214 
215 unsigned long int_sqrt(unsigned long);
216 
217 static inline void console_silent(void)
218 {
219 	console_loglevel = 0;
220 }
221 
222 static inline void console_verbose(void)
223 {
224 	if (console_loglevel)
225 		console_loglevel = 15;
226 }
227 
228 extern void bust_spinlocks(int yes);
229 extern void wake_up_klogd(void);
230 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
231 extern int panic_timeout;
232 extern int panic_on_oops;
233 extern int panic_on_unrecovered_nmi;
234 extern int tainted;
235 extern const char *print_tainted(void);
236 extern void add_taint(unsigned);
237 extern int root_mountflags;
238 
239 /* Values used for system_state */
240 extern enum system_states {
241 	SYSTEM_BOOTING,
242 	SYSTEM_RUNNING,
243 	SYSTEM_HALT,
244 	SYSTEM_POWER_OFF,
245 	SYSTEM_RESTART,
246 	SYSTEM_SUSPEND_DISK,
247 } system_state;
248 
249 #define TAINT_PROPRIETARY_MODULE	(1<<0)
250 #define TAINT_FORCED_MODULE		(1<<1)
251 #define TAINT_UNSAFE_SMP		(1<<2)
252 #define TAINT_FORCED_RMMOD		(1<<3)
253 #define TAINT_MACHINE_CHECK		(1<<4)
254 #define TAINT_BAD_PAGE			(1<<5)
255 #define TAINT_USER			(1<<6)
256 #define TAINT_DIE			(1<<7)
257 #define TAINT_OVERRIDDEN_ACPI_TABLE	(1<<8)
258 
259 extern void dump_stack(void) __cold;
260 
261 enum {
262 	DUMP_PREFIX_NONE,
263 	DUMP_PREFIX_ADDRESS,
264 	DUMP_PREFIX_OFFSET
265 };
266 extern void hex_dump_to_buffer(const void *buf, size_t len,
267 				int rowsize, int groupsize,
268 				char *linebuf, size_t linebuflen, bool ascii);
269 extern void print_hex_dump(const char *level, const char *prefix_str,
270 				int prefix_type, int rowsize, int groupsize,
271 				const void *buf, size_t len, bool ascii);
272 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
273 			const void *buf, size_t len);
274 #define hex_asc(x)	"0123456789abcdef"[x]
275 
276 #define pr_emerg(fmt, arg...) \
277 	printk(KERN_EMERG fmt, ##arg)
278 #define pr_alert(fmt, arg...) \
279 	printk(KERN_ALERT fmt, ##arg)
280 #define pr_crit(fmt, arg...) \
281 	printk(KERN_CRIT fmt, ##arg)
282 #define pr_err(fmt, arg...) \
283 	printk(KERN_ERR fmt, ##arg)
284 #define pr_warning(fmt, arg...) \
285 	printk(KERN_WARNING fmt, ##arg)
286 #define pr_notice(fmt, arg...) \
287 	printk(KERN_NOTICE fmt, ##arg)
288 #define pr_info(fmt, arg...) \
289 	printk(KERN_INFO fmt, ##arg)
290 
291 #ifdef DEBUG
292 /* If you are writing a driver, please use dev_dbg instead */
293 #define pr_debug(fmt, arg...) \
294 	printk(KERN_DEBUG fmt, ##arg)
295 #else
296 #define pr_debug(fmt, arg...) \
297 	({ if (0) printk(KERN_DEBUG fmt, ##arg); 0; })
298 #endif
299 
300 /*
301  *      Display an IP address in readable format.
302  */
303 
304 #define NIPQUAD(addr) \
305 	((unsigned char *)&addr)[0], \
306 	((unsigned char *)&addr)[1], \
307 	((unsigned char *)&addr)[2], \
308 	((unsigned char *)&addr)[3]
309 #define NIPQUAD_FMT "%u.%u.%u.%u"
310 
311 #define NIP6(addr) \
312 	ntohs((addr).s6_addr16[0]), \
313 	ntohs((addr).s6_addr16[1]), \
314 	ntohs((addr).s6_addr16[2]), \
315 	ntohs((addr).s6_addr16[3]), \
316 	ntohs((addr).s6_addr16[4]), \
317 	ntohs((addr).s6_addr16[5]), \
318 	ntohs((addr).s6_addr16[6]), \
319 	ntohs((addr).s6_addr16[7])
320 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
321 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
322 
323 #if defined(__LITTLE_ENDIAN)
324 #define HIPQUAD(addr) \
325 	((unsigned char *)&addr)[3], \
326 	((unsigned char *)&addr)[2], \
327 	((unsigned char *)&addr)[1], \
328 	((unsigned char *)&addr)[0]
329 #elif defined(__BIG_ENDIAN)
330 #define HIPQUAD	NIPQUAD
331 #else
332 #error "Please fix asm/byteorder.h"
333 #endif /* __LITTLE_ENDIAN */
334 
335 /*
336  * min()/max() macros that also do
337  * strict type-checking.. See the
338  * "unnecessary" pointer comparison.
339  */
340 #define min(x,y) ({ \
341 	typeof(x) _x = (x);	\
342 	typeof(y) _y = (y);	\
343 	(void) (&_x == &_y);		\
344 	_x < _y ? _x : _y; })
345 
346 #define max(x,y) ({ \
347 	typeof(x) _x = (x);	\
348 	typeof(y) _y = (y);	\
349 	(void) (&_x == &_y);		\
350 	_x > _y ? _x : _y; })
351 
352 /*
353  * ..and if you can't take the strict
354  * types, you can specify one yourself.
355  *
356  * Or not use min/max at all, of course.
357  */
358 #define min_t(type,x,y) \
359 	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
360 #define max_t(type,x,y) \
361 	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
362 
363 
364 /**
365  * container_of - cast a member of a structure out to the containing structure
366  * @ptr:	the pointer to the member.
367  * @type:	the type of the container struct this is embedded in.
368  * @member:	the name of the member within the struct.
369  *
370  */
371 #define container_of(ptr, type, member) ({			\
372 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
373 	(type *)( (char *)__mptr - offsetof(type,member) );})
374 
375 /*
376  * Check at compile time that something is of a particular type.
377  * Always evaluates to 1 so you may use it easily in comparisons.
378  */
379 #define typecheck(type,x) \
380 ({	type __dummy; \
381 	typeof(x) __dummy2; \
382 	(void)(&__dummy == &__dummy2); \
383 	1; \
384 })
385 
386 /*
387  * Check at compile time that 'function' is a certain type, or is a pointer
388  * to that type (needs to use typedef for the function type.)
389  */
390 #define typecheck_fn(type,function) \
391 ({	typeof(type) __tmp = function; \
392 	(void)__tmp; \
393 })
394 
395 struct sysinfo;
396 extern int do_sysinfo(struct sysinfo *info);
397 
398 #endif /* __KERNEL__ */
399 
400 #define SI_LOAD_SHIFT	16
401 struct sysinfo {
402 	long uptime;			/* Seconds since boot */
403 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
404 	unsigned long totalram;		/* Total usable main memory size */
405 	unsigned long freeram;		/* Available memory size */
406 	unsigned long sharedram;	/* Amount of shared memory */
407 	unsigned long bufferram;	/* Memory used by buffers */
408 	unsigned long totalswap;	/* Total swap space size */
409 	unsigned long freeswap;		/* swap space still available */
410 	unsigned short procs;		/* Number of current processes */
411 	unsigned short pad;		/* explicit padding for m68k */
412 	unsigned long totalhigh;	/* Total high memory size */
413 	unsigned long freehigh;		/* Available high memory size */
414 	unsigned int mem_unit;		/* Memory unit size in bytes */
415 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
416 };
417 
418 /* Force a compilation error if condition is true */
419 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
420 
421 /* Force a compilation error if condition is true, but also produce a
422    result (of value 0 and type size_t), so the expression can be used
423    e.g. in a structure initializer (or where-ever else comma expressions
424    aren't permitted). */
425 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
426 
427 /* Trap pasters of __FUNCTION__ at compile-time */
428 #define __FUNCTION__ (__func__)
429 
430 /* This helps us to avoid #ifdef CONFIG_NUMA */
431 #ifdef CONFIG_NUMA
432 #define NUMA_BUILD 1
433 #else
434 #define NUMA_BUILD 0
435 #endif
436 
437 #endif
438