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