xref: /linux-6.15/include/linux/kernel.h (revision 42fda663)
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))) == 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 extern int console_printk[];
80 
81 #define console_loglevel (console_printk[0])
82 #define default_message_loglevel (console_printk[1])
83 #define minimum_console_loglevel (console_printk[2])
84 #define default_console_loglevel (console_printk[3])
85 
86 struct completion;
87 struct pt_regs;
88 struct user;
89 
90 /**
91  * might_sleep - annotation for functions that can sleep
92  *
93  * this macro will print a stack trace if it is executed in an atomic
94  * context (spinlock, irq-handler, ...).
95  *
96  * This is a useful debugging help to be able to catch problems early and not
97  * be bitten later when the calling function happens to sleep when it is not
98  * supposed to.
99  */
100 #ifdef CONFIG_PREEMPT_VOLUNTARY
101 extern int cond_resched(void);
102 # define might_resched() cond_resched()
103 #else
104 # define might_resched() do { } while (0)
105 #endif
106 
107 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
108   void __might_sleep(char *file, int line);
109 # define might_sleep() \
110 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
111 #else
112 # define might_sleep() do { might_resched(); } while (0)
113 #endif
114 
115 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
116 
117 #define abs(x) ({				\
118 		int __x = (x);			\
119 		(__x < 0) ? -__x : __x;		\
120 	})
121 
122 extern struct atomic_notifier_head panic_notifier_list;
123 extern long (*panic_blink)(long time);
124 NORET_TYPE void panic(const char * fmt, ...)
125 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
126 extern void oops_enter(void);
127 extern void oops_exit(void);
128 extern int oops_may_print(void);
129 fastcall NORET_TYPE void do_exit(long error_code)
130 	ATTRIB_NORET;
131 NORET_TYPE void complete_and_exit(struct completion *, long)
132 	ATTRIB_NORET;
133 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
134 extern long simple_strtol(const char *,char **,unsigned int);
135 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
136 extern long long simple_strtoll(const char *,char **,unsigned int);
137 extern int sprintf(char * buf, const char * fmt, ...)
138 	__attribute__ ((format (printf, 2, 3)));
139 extern int vsprintf(char *buf, const char *, va_list)
140 	__attribute__ ((format (printf, 2, 0)));
141 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
142 	__attribute__ ((format (printf, 3, 4)));
143 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
144 	__attribute__ ((format (printf, 3, 0)));
145 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
146 	__attribute__ ((format (printf, 3, 4)));
147 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
148 	__attribute__ ((format (printf, 3, 0)));
149 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
150 	__attribute__ ((format (printf, 2, 3)));
151 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
152 
153 extern int sscanf(const char *, const char *, ...)
154 	__attribute__ ((format (scanf, 2, 3)));
155 extern int vsscanf(const char *, const char *, va_list)
156 	__attribute__ ((format (scanf, 2, 0)));
157 
158 extern int get_option(char **str, int *pint);
159 extern char *get_options(const char *str, int nints, int *ints);
160 extern unsigned long long memparse(char *ptr, char **retptr);
161 
162 extern int core_kernel_text(unsigned long addr);
163 extern int __kernel_text_address(unsigned long addr);
164 extern int kernel_text_address(unsigned long addr);
165 struct pid;
166 extern struct pid *session_of_pgrp(struct pid *pgrp);
167 
168 extern void dump_thread(struct pt_regs *regs, struct user *dump);
169 
170 #ifdef CONFIG_PRINTK
171 asmlinkage int vprintk(const char *fmt, va_list args)
172 	__attribute__ ((format (printf, 1, 0)));
173 asmlinkage int printk(const char * fmt, ...)
174 	__attribute__ ((format (printf, 1, 2))) __cold;
175 #else
176 static inline int vprintk(const char *s, va_list args)
177 	__attribute__ ((format (printf, 1, 0)));
178 static inline int vprintk(const char *s, va_list args) { return 0; }
179 static inline int printk(const char *s, ...)
180 	__attribute__ ((format (printf, 1, 2)));
181 static inline int __cold printk(const char *s, ...) { return 0; }
182 #endif
183 
184 unsigned long int_sqrt(unsigned long);
185 
186 extern int printk_ratelimit(void);
187 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
188 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
189 				unsigned int interval_msec);
190 
191 static inline void console_silent(void)
192 {
193 	console_loglevel = 0;
194 }
195 
196 static inline void console_verbose(void)
197 {
198 	if (console_loglevel)
199 		console_loglevel = 15;
200 }
201 
202 extern void bust_spinlocks(int yes);
203 extern void wake_up_klogd(void);
204 extern int oops_in_progress;		/* If set, an oops, panic(), BUG() or die() is in progress */
205 extern int panic_timeout;
206 extern int panic_on_oops;
207 extern int panic_on_unrecovered_nmi;
208 extern int tainted;
209 extern const char *print_tainted(void);
210 extern void add_taint(unsigned);
211 
212 /* Values used for system_state */
213 extern enum system_states {
214 	SYSTEM_BOOTING,
215 	SYSTEM_RUNNING,
216 	SYSTEM_HALT,
217 	SYSTEM_POWER_OFF,
218 	SYSTEM_RESTART,
219 	SYSTEM_SUSPEND_DISK,
220 } system_state;
221 
222 #define TAINT_PROPRIETARY_MODULE	(1<<0)
223 #define TAINT_FORCED_MODULE		(1<<1)
224 #define TAINT_UNSAFE_SMP		(1<<2)
225 #define TAINT_FORCED_RMMOD		(1<<3)
226 #define TAINT_MACHINE_CHECK		(1<<4)
227 #define TAINT_BAD_PAGE			(1<<5)
228 #define TAINT_USER			(1<<6)
229 #define TAINT_DIE			(1<<7)
230 
231 extern void dump_stack(void) __cold;
232 
233 enum {
234 	DUMP_PREFIX_NONE,
235 	DUMP_PREFIX_ADDRESS,
236 	DUMP_PREFIX_OFFSET
237 };
238 extern void hex_dump_to_buffer(const void *buf, size_t len,
239 				int rowsize, int groupsize,
240 				char *linebuf, size_t linebuflen, bool ascii);
241 extern void print_hex_dump(const char *level, const char *prefix_str,
242 				int prefix_type, int rowsize, int groupsize,
243 				const void *buf, size_t len, bool ascii);
244 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
245 			const void *buf, size_t len);
246 #define hex_asc(x)	"0123456789abcdef"[x]
247 
248 #ifdef DEBUG
249 /* If you are writing a driver, please use dev_dbg instead */
250 #define pr_debug(fmt,arg...) \
251 	printk(KERN_DEBUG fmt,##arg)
252 #else
253 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
254 {
255 	return 0;
256 }
257 #endif
258 
259 #define pr_info(fmt,arg...) \
260 	printk(KERN_INFO fmt,##arg)
261 
262 /*
263  *      Display an IP address in readable format.
264  */
265 
266 #define NIPQUAD(addr) \
267 	((unsigned char *)&addr)[0], \
268 	((unsigned char *)&addr)[1], \
269 	((unsigned char *)&addr)[2], \
270 	((unsigned char *)&addr)[3]
271 #define NIPQUAD_FMT "%u.%u.%u.%u"
272 
273 #define NIP6(addr) \
274 	ntohs((addr).s6_addr16[0]), \
275 	ntohs((addr).s6_addr16[1]), \
276 	ntohs((addr).s6_addr16[2]), \
277 	ntohs((addr).s6_addr16[3]), \
278 	ntohs((addr).s6_addr16[4]), \
279 	ntohs((addr).s6_addr16[5]), \
280 	ntohs((addr).s6_addr16[6]), \
281 	ntohs((addr).s6_addr16[7])
282 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
283 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
284 
285 #if defined(__LITTLE_ENDIAN)
286 #define HIPQUAD(addr) \
287 	((unsigned char *)&addr)[3], \
288 	((unsigned char *)&addr)[2], \
289 	((unsigned char *)&addr)[1], \
290 	((unsigned char *)&addr)[0]
291 #elif defined(__BIG_ENDIAN)
292 #define HIPQUAD	NIPQUAD
293 #else
294 #error "Please fix asm/byteorder.h"
295 #endif /* __LITTLE_ENDIAN */
296 
297 /*
298  * min()/max() macros that also do
299  * strict type-checking.. See the
300  * "unnecessary" pointer comparison.
301  */
302 #define min(x,y) ({ \
303 	typeof(x) _x = (x);	\
304 	typeof(y) _y = (y);	\
305 	(void) (&_x == &_y);		\
306 	_x < _y ? _x : _y; })
307 
308 #define max(x,y) ({ \
309 	typeof(x) _x = (x);	\
310 	typeof(y) _y = (y);	\
311 	(void) (&_x == &_y);		\
312 	_x > _y ? _x : _y; })
313 
314 /*
315  * ..and if you can't take the strict
316  * types, you can specify one yourself.
317  *
318  * Or not use min/max at all, of course.
319  */
320 #define min_t(type,x,y) \
321 	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
322 #define max_t(type,x,y) \
323 	({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
324 
325 
326 /**
327  * container_of - cast a member of a structure out to the containing structure
328  * @ptr:	the pointer to the member.
329  * @type:	the type of the container struct this is embedded in.
330  * @member:	the name of the member within the struct.
331  *
332  */
333 #define container_of(ptr, type, member) ({			\
334 	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
335 	(type *)( (char *)__mptr - offsetof(type,member) );})
336 
337 /*
338  * Check at compile time that something is of a particular type.
339  * Always evaluates to 1 so you may use it easily in comparisons.
340  */
341 #define typecheck(type,x) \
342 ({	type __dummy; \
343 	typeof(x) __dummy2; \
344 	(void)(&__dummy == &__dummy2); \
345 	1; \
346 })
347 
348 /*
349  * Check at compile time that 'function' is a certain type, or is a pointer
350  * to that type (needs to use typedef for the function type.)
351  */
352 #define typecheck_fn(type,function) \
353 ({	typeof(type) __tmp = function; \
354 	(void)__tmp; \
355 })
356 
357 struct sysinfo;
358 extern int do_sysinfo(struct sysinfo *info);
359 
360 #endif /* __KERNEL__ */
361 
362 #define SI_LOAD_SHIFT	16
363 struct sysinfo {
364 	long uptime;			/* Seconds since boot */
365 	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
366 	unsigned long totalram;		/* Total usable main memory size */
367 	unsigned long freeram;		/* Available memory size */
368 	unsigned long sharedram;	/* Amount of shared memory */
369 	unsigned long bufferram;	/* Memory used by buffers */
370 	unsigned long totalswap;	/* Total swap space size */
371 	unsigned long freeswap;		/* swap space still available */
372 	unsigned short procs;		/* Number of current processes */
373 	unsigned short pad;		/* explicit padding for m68k */
374 	unsigned long totalhigh;	/* Total high memory size */
375 	unsigned long freehigh;		/* Available high memory size */
376 	unsigned int mem_unit;		/* Memory unit size in bytes */
377 	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
378 };
379 
380 /* Force a compilation error if condition is true */
381 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
382 
383 /* Force a compilation error if condition is true, but also produce a
384    result (of value 0 and type size_t), so the expression can be used
385    e.g. in a structure initializer (or where-ever else comma expressions
386    aren't permitted). */
387 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
388 
389 /* Trap pasters of __FUNCTION__ at compile-time */
390 #define __FUNCTION__ (__func__)
391 
392 /* This helps us to avoid #ifdef CONFIG_NUMA */
393 #ifdef CONFIG_NUMA
394 #define NUMA_BUILD 1
395 #else
396 #define NUMA_BUILD 0
397 #endif
398 
399 #endif
400