xref: /linux-6.15/include/linux/kernel.h (revision 2b8232ce)
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 #ifdef CONFIG_LBD
46 # include <asm/div64.h>
47 # define sector_div(a, b) do_div(a, b)
48 #else
49 # define sector_div(n, b)( \
50 { \
51 	int _res; \
52 	_res = (n) % (b); \
53 	(n) /= (b); \
54 	_res; \
55 } \
56 )
57 #endif
58 
59 /**
60  * upper_32_bits - return bits 32-63 of a number
61  * @n: the number we're accessing
62  *
63  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
64  * the "right shift count >= width of type" warning when that quantity is
65  * 32-bits.
66  */
67 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
68 
69 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
70 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
71 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
72 #define	KERN_ERR	"<3>"	/* error conditions			*/
73 #define	KERN_WARNING	"<4>"	/* warning conditions			*/
74 #define	KERN_NOTICE	"<5>"	/* normal but significant condition	*/
75 #define	KERN_INFO	"<6>"	/* informational			*/
76 #define	KERN_DEBUG	"<7>"	/* debug-level messages			*/
77 
78 extern int console_printk[];
79 
80 #define console_loglevel (console_printk[0])
81 #define default_message_loglevel (console_printk[1])
82 #define minimum_console_loglevel (console_printk[2])
83 #define default_console_loglevel (console_printk[3])
84 
85 struct completion;
86 struct pt_regs;
87 struct user;
88 
89 /**
90  * might_sleep - annotation for functions that can sleep
91  *
92  * this macro will print a stack trace if it is executed in an atomic
93  * context (spinlock, irq-handler, ...).
94  *
95  * This is a useful debugging help to be able to catch problems early and not
96  * be bitten later when the calling function happens to sleep when it is not
97  * supposed to.
98  */
99 #ifdef CONFIG_PREEMPT_VOLUNTARY
100 extern int cond_resched(void);
101 # define might_resched() cond_resched()
102 #else
103 # define might_resched() do { } while (0)
104 #endif
105 
106 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
107   void __might_sleep(char *file, int line);
108 # define might_sleep() \
109 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
110 #else
111 # define might_sleep() do { might_resched(); } while (0)
112 #endif
113 
114 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
115 
116 #define abs(x) ({				\
117 		int __x = (x);			\
118 		(__x < 0) ? -__x : __x;		\
119 	})
120 
121 extern struct atomic_notifier_head panic_notifier_list;
122 extern long (*panic_blink)(long time);
123 NORET_TYPE void panic(const char * fmt, ...)
124 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
125 extern void oops_enter(void);
126 extern void oops_exit(void);
127 extern int oops_may_print(void);
128 fastcall NORET_TYPE void do_exit(long error_code)
129 	ATTRIB_NORET;
130 NORET_TYPE void complete_and_exit(struct completion *, long)
131 	ATTRIB_NORET;
132 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
133 extern long simple_strtol(const char *,char **,unsigned int);
134 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
135 extern long long simple_strtoll(const char *,char **,unsigned int);
136 extern int sprintf(char * buf, const char * fmt, ...)
137 	__attribute__ ((format (printf, 2, 3)));
138 extern int vsprintf(char *buf, const char *, va_list)
139 	__attribute__ ((format (printf, 2, 0)));
140 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
141 	__attribute__ ((format (printf, 3, 4)));
142 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
143 	__attribute__ ((format (printf, 3, 0)));
144 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
145 	__attribute__ ((format (printf, 3, 4)));
146 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
147 	__attribute__ ((format (printf, 3, 0)));
148 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
149 	__attribute__ ((format (printf, 2, 3)));
150 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
151 
152 extern int sscanf(const char *, const char *, ...)
153 	__attribute__ ((format (scanf, 2, 3)));
154 extern int vsscanf(const char *, const char *, va_list)
155 	__attribute__ ((format (scanf, 2, 0)));
156 
157 extern int get_option(char **str, int *pint);
158 extern char *get_options(const char *str, int nints, int *ints);
159 extern unsigned long long memparse(char *ptr, char **retptr);
160 
161 extern int core_kernel_text(unsigned long addr);
162 extern int __kernel_text_address(unsigned long addr);
163 extern int kernel_text_address(unsigned long addr);
164 struct pid;
165 extern struct pid *session_of_pgrp(struct pid *pgrp);
166 
167 extern void dump_thread(struct pt_regs *regs, struct user *dump);
168 
169 #ifdef CONFIG_PRINTK
170 asmlinkage int vprintk(const char *fmt, va_list args)
171 	__attribute__ ((format (printf, 1, 0)));
172 asmlinkage int printk(const char * fmt, ...)
173 	__attribute__ ((format (printf, 1, 2))) __cold;
174 #else
175 static inline int vprintk(const char *s, va_list args)
176 	__attribute__ ((format (printf, 1, 0)));
177 static inline int vprintk(const char *s, va_list args) { return 0; }
178 static inline int printk(const char *s, ...)
179 	__attribute__ ((format (printf, 1, 2)));
180 static inline int __cold printk(const char *s, ...) { return 0; }
181 #endif
182 
183 unsigned long int_sqrt(unsigned long);
184 
185 extern int printk_ratelimit(void);
186 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
187 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
188 				unsigned int interval_msec);
189 
190 static inline void console_silent(void)
191 {
192 	console_loglevel = 0;
193 }
194 
195 static inline void console_verbose(void)
196 {
197 	if (console_loglevel)
198 		console_loglevel = 15;
199 }
200 
201 extern void bust_spinlocks(int yes);
202 extern void wake_up_klogd(void);
203 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
204 extern int panic_timeout;
205 extern int panic_on_oops;
206 extern int panic_on_unrecovered_nmi;
207 extern int tainted;
208 extern const char *print_tainted(void);
209 extern void add_taint(unsigned);
210 
211 /* Values used for system_state */
212 extern enum system_states {
213 	SYSTEM_BOOTING,
214 	SYSTEM_RUNNING,
215 	SYSTEM_HALT,
216 	SYSTEM_POWER_OFF,
217 	SYSTEM_RESTART,
218 	SYSTEM_SUSPEND_DISK,
219 } system_state;
220 
221 #define TAINT_PROPRIETARY_MODULE	(1<<0)
222 #define TAINT_FORCED_MODULE		(1<<1)
223 #define TAINT_UNSAFE_SMP		(1<<2)
224 #define TAINT_FORCED_RMMOD		(1<<3)
225 #define TAINT_MACHINE_CHECK		(1<<4)
226 #define TAINT_BAD_PAGE			(1<<5)
227 #define TAINT_USER			(1<<6)
228 #define TAINT_DIE			(1<<7)
229 
230 extern void dump_stack(void) __cold;
231 
232 enum {
233 	DUMP_PREFIX_NONE,
234 	DUMP_PREFIX_ADDRESS,
235 	DUMP_PREFIX_OFFSET
236 };
237 extern void hex_dump_to_buffer(const void *buf, size_t len,
238 				int rowsize, int groupsize,
239 				char *linebuf, size_t linebuflen, bool ascii);
240 extern void print_hex_dump(const char *level, const char *prefix_str,
241 				int prefix_type, int rowsize, int groupsize,
242 				const void *buf, size_t len, bool ascii);
243 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
244 			const void *buf, size_t len);
245 #define hex_asc(x)	"0123456789abcdef"[x]
246 
247 #ifdef DEBUG
248 /* If you are writing a driver, please use dev_dbg instead */
249 #define pr_debug(fmt,arg...) \
250 	printk(KERN_DEBUG fmt,##arg)
251 #else
252 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
253 {
254 	return 0;
255 }
256 #endif
257 
258 #define pr_info(fmt,arg...) \
259 	printk(KERN_INFO fmt,##arg)
260 
261 /*
262  *      Display an IP address in readable format.
263  */
264 
265 #define NIPQUAD(addr) \
266 	((unsigned char *)&addr)[0], \
267 	((unsigned char *)&addr)[1], \
268 	((unsigned char *)&addr)[2], \
269 	((unsigned char *)&addr)[3]
270 #define NIPQUAD_FMT "%u.%u.%u.%u"
271 
272 #define NIP6(addr) \
273 	ntohs((addr).s6_addr16[0]), \
274 	ntohs((addr).s6_addr16[1]), \
275 	ntohs((addr).s6_addr16[2]), \
276 	ntohs((addr).s6_addr16[3]), \
277 	ntohs((addr).s6_addr16[4]), \
278 	ntohs((addr).s6_addr16[5]), \
279 	ntohs((addr).s6_addr16[6]), \
280 	ntohs((addr).s6_addr16[7])
281 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
282 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
283 
284 #if defined(__LITTLE_ENDIAN)
285 #define HIPQUAD(addr) \
286 	((unsigned char *)&addr)[3], \
287 	((unsigned char *)&addr)[2], \
288 	((unsigned char *)&addr)[1], \
289 	((unsigned char *)&addr)[0]
290 #elif defined(__BIG_ENDIAN)
291 #define HIPQUAD	NIPQUAD
292 #else
293 #error "Please fix asm/byteorder.h"
294 #endif /* __LITTLE_ENDIAN */
295 
296 /*
297  * min()/max() macros that also do
298  * strict type-checking.. See the
299  * "unnecessary" pointer comparison.
300  */
301 #define min(x,y) ({ \
302 	typeof(x) _x = (x);	\
303 	typeof(y) _y = (y);	\
304 	(void) (&_x == &_y);		\
305 	_x < _y ? _x : _y; })
306 
307 #define max(x,y) ({ \
308 	typeof(x) _x = (x);	\
309 	typeof(y) _y = (y);	\
310 	(void) (&_x == &_y);		\
311 	_x > _y ? _x : _y; })
312 
313 /*
314  * ..and if you can't take the strict
315  * types, you can specify one yourself.
316  *
317  * Or not use min/max at all, of course.
318  */
319 #define min_t(type,x,y) \
320 	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
321 #define max_t(type,x,y) \
322 	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
323 
324 
325 /**
326  * container_of - cast a member of a structure out to the containing structure
327  * @ptr:	the pointer to the member.
328  * @type:	the type of the container struct this is embedded in.
329  * @member:	the name of the member within the struct.
330  *
331  */
332 #define container_of(ptr, type, member) ({			\
333 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
334 	(type *)( (char *)__mptr - offsetof(type,member) );})
335 
336 /*
337  * Check at compile time that something is of a particular type.
338  * Always evaluates to 1 so you may use it easily in comparisons.
339  */
340 #define typecheck(type,x) \
341 ({	type __dummy; \
342 	typeof(x) __dummy2; \
343 	(void)(&__dummy == &__dummy2); \
344 	1; \
345 })
346 
347 /*
348  * Check at compile time that 'function' is a certain type, or is a pointer
349  * to that type (needs to use typedef for the function type.)
350  */
351 #define typecheck_fn(type,function) \
352 ({	typeof(type) __tmp = function; \
353 	(void)__tmp; \
354 })
355 
356 struct sysinfo;
357 extern int do_sysinfo(struct sysinfo *info);
358 
359 #endif /* __KERNEL__ */
360 
361 #define SI_LOAD_SHIFT	16
362 struct sysinfo {
363 	long uptime;			/* Seconds since boot */
364 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
365 	unsigned long totalram;		/* Total usable main memory size */
366 	unsigned long freeram;		/* Available memory size */
367 	unsigned long sharedram;	/* Amount of shared memory */
368 	unsigned long bufferram;	/* Memory used by buffers */
369 	unsigned long totalswap;	/* Total swap space size */
370 	unsigned long freeswap;		/* swap space still available */
371 	unsigned short procs;		/* Number of current processes */
372 	unsigned short pad;		/* explicit padding for m68k */
373 	unsigned long totalhigh;	/* Total high memory size */
374 	unsigned long freehigh;		/* Available high memory size */
375 	unsigned int mem_unit;		/* Memory unit size in bytes */
376 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
377 };
378 
379 /* Force a compilation error if condition is true */
380 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
381 
382 /* Force a compilation error if condition is true, but also produce a
383    result (of value 0 and type size_t), so the expression can be used
384    e.g. in a structure initializer (or where-ever else comma expressions
385    aren't permitted). */
386 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
387 
388 /* Trap pasters of __FUNCTION__ at compile-time */
389 #define __FUNCTION__ (__func__)
390 
391 /* This helps us to avoid #ifdef CONFIG_NUMA */
392 #ifdef CONFIG_NUMA
393 #define NUMA_BUILD 1
394 #else
395 #define NUMA_BUILD 0
396 #endif
397 
398 #endif
399