include/linux/kernel.h

   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 extern int log_buf_get_len(void);
 176 extern int log_buf_read(int idx);
 177 extern int log_buf_copy(char *dest, int idx, int len);
 178 #else
 179 static inline int vprintk(const char *s, va_list args)
 180         __attribute__ ((format (printf, 1, 0)));
 181 static inline int vprintk(const char *s, va_list args) { return 0; }
 182 static inline int printk(const char *s, ...)
 183         __attribute__ ((format (printf, 1, 2)));
 184 static inline int __cold printk(const char *s, ...) { return 0; }
 185 static inline int log_buf_get_len(void) { return 0; }
 186 static inline int log_buf_read(int idx) { return 0; }
 187 static inline int log_buf_copy(char *dest, int idx, int len) { return 0; }
 188 #endif
 189
 190 unsigned long int_sqrt(unsigned long);
 191
 192 extern int printk_ratelimit(void);
 193 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 194 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 195                                 unsigned int interval_msec);
 196
 197 static inline void console_silent(void)
 198 {
 199         console_loglevel = 0;
 200 }
 201
 202 static inline void console_verbose(void)
 203 {
 204         if (console_loglevel)
 205                 console_loglevel = 15;
 206 }
 207
 208 extern void bust_spinlocks(int yes);
 209 extern void wake_up_klogd(void);
 210 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 211 extern int panic_timeout;
 212 extern int panic_on_oops;
 213 extern int panic_on_unrecovered_nmi;
 214 extern int tainted;
 215 extern const char *print_tainted(void);
 216 extern void add_taint(unsigned);
 217
 218 /* Values used for system_state */
 219 extern enum system_states {
 220         SYSTEM_BOOTING,
 221         SYSTEM_RUNNING,
 222         SYSTEM_HALT,
 223         SYSTEM_POWER_OFF,
 224         SYSTEM_RESTART,
 225         SYSTEM_SUSPEND_DISK,
 226 } system_state;
 227
 228 #define TAINT_PROPRIETARY_MODULE        (1<<0)
 229 #define TAINT_FORCED_MODULE             (1<<1)
 230 #define TAINT_UNSAFE_SMP                (1<<2)
 231 #define TAINT_FORCED_RMMOD              (1<<3)
 232 #define TAINT_MACHINE_CHECK             (1<<4)
 233 #define TAINT_BAD_PAGE                  (1<<5)
 234 #define TAINT_USER                      (1<<6)
 235 #define TAINT_DIE                       (1<<7)
 236
 237 extern void dump_stack(void) __cold;
 238
 239 enum {
 240         DUMP_PREFIX_NONE,
 241         DUMP_PREFIX_ADDRESS,
 242         DUMP_PREFIX_OFFSET
 243 };
 244 extern void hex_dump_to_buffer(const void *buf, size_t len,
 245                                 int rowsize, int groupsize,
 246                                 char *linebuf, size_t linebuflen, bool ascii);
 247 extern void print_hex_dump(const char *level, const char *prefix_str,
 248                                 int prefix_type, int rowsize, int groupsize,
 249                                 const void *buf, size_t len, bool ascii);
 250 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 251                         const void *buf, size_t len);
 252 #define hex_asc(x)      "0123456789abcdef"[x]
 253
 254 #ifdef DEBUG
 255 /* If you are writing a driver, please use dev_dbg instead */
 256 #define pr_debug(fmt,arg...) \
 257         printk(KERN_DEBUG fmt,##arg)
 258 #else
 259 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
 260 {
 261         return 0;
 262 }
 263 #endif
 264
 265 #define pr_info(fmt,arg...) \
 266         printk(KERN_INFO fmt,##arg)
 267
 268 /*
 269  *      Display an IP address in readable format.
 270  */
 271
 272 #define NIPQUAD(addr) \
 273         ((unsigned char *)&addr)[0], \
 274         ((unsigned char *)&addr)[1], \
 275         ((unsigned char *)&addr)[2], \
 276         ((unsigned char *)&addr)[3]
 277 #define NIPQUAD_FMT "%u.%u.%u.%u"
 278
 279 #define NIP6(addr) \
 280         ntohs((addr).s6_addr16[0]), \
 281         ntohs((addr).s6_addr16[1]), \
 282         ntohs((addr).s6_addr16[2]), \
 283         ntohs((addr).s6_addr16[3]), \
 284         ntohs((addr).s6_addr16[4]), \
 285         ntohs((addr).s6_addr16[5]), \
 286         ntohs((addr).s6_addr16[6]), \
 287         ntohs((addr).s6_addr16[7])
 288 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
 289 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
 290
 291 #if defined(__LITTLE_ENDIAN)
 292 #define HIPQUAD(addr) \
 293         ((unsigned char *)&addr)[3], \
 294         ((unsigned char *)&addr)[2], \
 295         ((unsigned char *)&addr)[1], \
 296         ((unsigned char *)&addr)[0]
 297 #elif defined(__BIG_ENDIAN)
 298 #define HIPQUAD NIPQUAD
 299 #else
 300 #error "Please fix asm/byteorder.h"
 301 #endif /* __LITTLE_ENDIAN */
 302
 303 /*
 304  * min()/max() macros that also do
 305  * strict type-checking.. See the
 306  * "unnecessary" pointer comparison.
 307  */
 308 #define min(x,y) ({ \
 309         typeof(x) _x = (x);     \
 310         typeof(y) _y = (y);     \
 311         (void) (&_x == &_y);            \
 312         _x < _y ? _x : _y; })
 313
 314 #define max(x,y) ({ \
 315         typeof(x) _x = (x);     \
 316         typeof(y) _y = (y);     \
 317         (void) (&_x == &_y);            \
 318         _x > _y ? _x : _y; })
 319
 320 /*
 321  * ..and if you can't take the strict
 322  * types, you can specify one yourself.
 323  *
 324  * Or not use min/max at all, of course.
 325  */
 326 #define min_t(type,x,y) \
 327         ({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
 328 #define max_t(type,x,y) \
 329         ({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
 330
 331
 332 /**
 333  * container_of - cast a member of a structure out to the containing structure
 334  * @ptr:        the pointer to the member.
 335  * @type:       the type of the container struct this is embedded in.
 336  * @member:     the name of the member within the struct.
 337  *
 338  */
 339 #define container_of(ptr, type, member) ({                      \
 340         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 341         (type *)( (char *)__mptr - offsetof(type,member) );})
 342
 343 /*
 344  * Check at compile time that something is of a particular type.
 345  * Always evaluates to 1 so you may use it easily in comparisons.
 346  */
 347 #define typecheck(type,x) \
 348 ({      type __dummy; \
 349         typeof(x) __dummy2; \
 350         (void)(&__dummy == &__dummy2); \
 351         1; \
 352 })
 353
 354 /*
 355  * Check at compile time that 'function' is a certain type, or is a pointer
 356  * to that type (needs to use typedef for the function type.)
 357  */
 358 #define typecheck_fn(type,function) \
 359 ({      typeof(type) __tmp = function; \
 360         (void)__tmp; \
 361 })
 362
 363 struct sysinfo;
 364 extern int do_sysinfo(struct sysinfo *info);
 365
 366 #endif /* __KERNEL__ */
 367
 368 #define SI_LOAD_SHIFT   16
 369 struct sysinfo {
 370         long uptime;                    /* Seconds since boot */
 371         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 372         unsigned long totalram;         /* Total usable main memory size */
 373         unsigned long freeram;          /* Available memory size */
 374         unsigned long sharedram;        /* Amount of shared memory */
 375         unsigned long bufferram;        /* Memory used by buffers */
 376         unsigned long totalswap;        /* Total swap space size */
 377         unsigned long freeswap;         /* swap space still available */
 378         unsigned short procs;           /* Number of current processes */
 379         unsigned short pad;             /* explicit padding for m68k */
 380         unsigned long totalhigh;        /* Total high memory size */
 381         unsigned long freehigh;         /* Available high memory size */
 382         unsigned int mem_unit;          /* Memory unit size in bytes */
 383         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 384 };
 385
 386 /* Force a compilation error if condition is true */
 387 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 388
 389 /* Force a compilation error if condition is true, but also produce a
 390    result (of value 0 and type size_t), so the expression can be used
 391    e.g. in a structure initializer (or where-ever else comma expressions
 392    aren't permitted). */
 393 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 394
 395 /* Trap pasters of __FUNCTION__ at compile-time */
 396 #define __FUNCTION__ (__func__)
 397
 398 /* This helps us to avoid #ifdef CONFIG_NUMA */
 399 #ifdef CONFIG_NUMA
 400 #define NUMA_BUILD 1
 401 #else
 402 #define NUMA_BUILD 0
 403 #endif
 404
 405 #endif