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 <linux/typecheck.h>
  18 #include <linux/ratelimit.h>
  19 #include <linux/dynamic_debug.h>
  20 #include <asm/byteorder.h>
  21 #include <asm/bug.h>
  22
  23 extern const char linux_banner[];
  24 extern const char linux_proc_banner[];
  25
  26 #define USHORT_MAX      ((u16)(~0U))
  27 #define SHORT_MAX       ((s16)(USHORT_MAX>>1))
  28 #define SHORT_MIN       (-SHORT_MAX - 1)
  29 #define INT_MAX         ((int)(~0U>>1))
  30 #define INT_MIN         (-INT_MAX - 1)
  31 #define UINT_MAX        (~0U)
  32 #define LONG_MAX        ((long)(~0UL>>1))
  33 #define LONG_MIN        (-LONG_MAX - 1)
  34 #define ULONG_MAX       (~0UL)
  35 #define LLONG_MAX       ((long long)(~0ULL>>1))
  36 #define LLONG_MIN       (-LLONG_MAX - 1)
  37 #define ULLONG_MAX      (~0ULL)
  38
  39 #define STACK_MAGIC     0xdeadbeef
  40
  41 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  42 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  43 #define PTR_ALIGN(p, a)         ((typeof(p))ALIGN((unsigned long)(p), (a)))
  44 #define IS_ALIGNED(x, a)                (((x) & ((typeof(x))(a) - 1)) == 0)
  45
  46 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  47
  48 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  49 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  50 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  51 #define DIV_ROUND_CLOSEST(x, divisor)(                  \
  52 {                                                       \
  53         typeof(divisor) __divisor = divisor;            \
  54         (((x) + ((__divisor) / 2)) / (__divisor));      \
  55 }                                                       \
  56 )
  57
  58 #define _RET_IP_                (unsigned long)__builtin_return_address(0)
  59 #define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
  60
  61 #ifdef CONFIG_LBD
  62 # include <asm/div64.h>
  63 # define sector_div(a, b) do_div(a, b)
  64 #else
  65 # define sector_div(n, b)( \
  66 { \
  67         int _res; \
  68         _res = (n) % (b); \
  69         (n) /= (b); \
  70         _res; \
  71 } \
  72 )
  73 #endif
  74
  75 /**
  76  * upper_32_bits - return bits 32-63 of a number
  77  * @n: the number we're accessing
  78  *
  79  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
  80  * the "right shift count >= width of type" warning when that quantity is
  81  * 32-bits.
  82  */
  83 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  84
  85 /**
  86  * lower_32_bits - return bits 0-31 of a number
  87  * @n: the number we're accessing
  88  */
  89 #define lower_32_bits(n) ((u32)(n))
  90
  91 #define KERN_EMERG      "<0>"   /* system is unusable                   */
  92 #define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  93 #define KERN_CRIT       "<2>"   /* critical conditions                  */
  94 #define KERN_ERR        "<3>"   /* error conditions                     */
  95 #define KERN_WARNING    "<4>"   /* warning conditions                   */
  96 #define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  97 #define KERN_INFO       "<6>"   /* informational                        */
  98 #define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  99
 100 /*
 101  * Annotation for a "continued" line of log printout (only done after a
 102  * line that had no enclosing \n). Only to be used by core/arch code
 103  * during early bootup (a continued line is not SMP-safe otherwise).
 104  */
 105 #define KERN_CONT       ""
 106
 107 extern int console_printk[];
 108
 109 #define console_loglevel (console_printk[0])
 110 #define default_message_loglevel (console_printk[1])
 111 #define minimum_console_loglevel (console_printk[2])
 112 #define default_console_loglevel (console_printk[3])
 113
 114 struct completion;
 115 struct pt_regs;
 116 struct user;
 117
 118 #ifdef CONFIG_PREEMPT_VOLUNTARY
 119 extern int _cond_resched(void);
 120 # define might_resched() _cond_resched()
 121 #else
 122 # define might_resched() do { } while (0)
 123 #endif
 124
 125 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 126   void __might_sleep(char *file, int line);
 127 /**
 128  * might_sleep - annotation for functions that can sleep
 129  *
 130  * this macro will print a stack trace if it is executed in an atomic
 131  * context (spinlock, irq-handler, ...).
 132  *
 133  * This is a useful debugging help to be able to catch problems early and not
 134  * be bitten later when the calling function happens to sleep when it is not
 135  * supposed to.
 136  */
 137 # define might_sleep() \
 138         do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
 139 #else
 140 # define might_sleep() do { might_resched(); } while (0)
 141 #endif
 142
 143 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 144
 145 #define abs(x) ({                               \
 146                 int __x = (x);                  \
 147                 (__x < 0) ? -__x : __x;         \
 148         })
 149
 150 #ifdef CONFIG_PROVE_LOCKING
 151 void might_fault(void);
 152 #else
 153 static inline void might_fault(void)
 154 {
 155         might_sleep();
 156 }
 157 #endif
 158
 159 extern struct atomic_notifier_head panic_notifier_list;
 160 extern long (*panic_blink)(long time);
 161 NORET_TYPE void panic(const char * fmt, ...)
 162         __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 163 extern void oops_enter(void);
 164 extern void oops_exit(void);
 165 extern int oops_may_print(void);
 166 NORET_TYPE void do_exit(long error_code)
 167         ATTRIB_NORET;
 168 NORET_TYPE void complete_and_exit(struct completion *, long)
 169         ATTRIB_NORET;
 170 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 171 extern long simple_strtol(const char *,char **,unsigned int);
 172 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 173 extern long long simple_strtoll(const char *,char **,unsigned int);
 174 extern int strict_strtoul(const char *, unsigned int, unsigned long *);
 175 extern int strict_strtol(const char *, unsigned int, long *);
 176 extern int strict_strtoull(const char *, unsigned int, unsigned long long *);
 177 extern int strict_strtoll(const char *, unsigned int, long long *);
 178 extern int sprintf(char * buf, const char * fmt, ...)
 179         __attribute__ ((format (printf, 2, 3)));
 180 extern int vsprintf(char *buf, const char *, va_list)
 181         __attribute__ ((format (printf, 2, 0)));
 182 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 183         __attribute__ ((format (printf, 3, 4)));
 184 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 185         __attribute__ ((format (printf, 3, 0)));
 186 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 187         __attribute__ ((format (printf, 3, 4)));
 188 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 189         __attribute__ ((format (printf, 3, 0)));
 190 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 191         __attribute__ ((format (printf, 2, 3)));
 192 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 193
 194 extern int sscanf(const char *, const char *, ...)
 195         __attribute__ ((format (scanf, 2, 3)));
 196 extern int vsscanf(const char *, const char *, va_list)
 197         __attribute__ ((format (scanf, 2, 0)));
 198
 199 extern int get_option(char **str, int *pint);
 200 extern char *get_options(const char *str, int nints, int *ints);
 201 extern unsigned long long memparse(const char *ptr, char **retptr);
 202
 203 extern int core_kernel_text(unsigned long addr);
 204 extern int __kernel_text_address(unsigned long addr);
 205 extern int kernel_text_address(unsigned long addr);
 206 extern int func_ptr_is_kernel_text(void *ptr);
 207
 208 struct pid;
 209 extern struct pid *session_of_pgrp(struct pid *pgrp);
 210
 211 /*
 212  * FW_BUG
 213  * Add this to a message where you are sure the firmware is buggy or behaves
 214  * really stupid or out of spec. Be aware that the responsible BIOS developer
 215  * should be able to fix this issue or at least get a concrete idea of the
 216  * problem by reading your message without the need of looking at the kernel
 217  * code.
 218  *
 219  * Use it for definite and high priority BIOS bugs.
 220  *
 221  * FW_WARN
 222  * Use it for not that clear (e.g. could the kernel messed up things already?)
 223  * and medium priority BIOS bugs.
 224  *
 225  * FW_INFO
 226  * Use this one if you want to tell the user or vendor about something
 227  * suspicious, but generally harmless related to the firmware.
 228  *
 229  * Use it for information or very low priority BIOS bugs.
 230  */
 231 #define FW_BUG          "[Firmware Bug]: "
 232 #define FW_WARN         "[Firmware Warn]: "
 233 #define FW_INFO         "[Firmware Info]: "
 234
 235 #ifdef CONFIG_PRINTK
 236 asmlinkage int vprintk(const char *fmt, va_list args)
 237         __attribute__ ((format (printf, 1, 0)));
 238 asmlinkage int printk(const char * fmt, ...)
 239         __attribute__ ((format (printf, 1, 2))) __cold;
 240
 241 extern struct ratelimit_state printk_ratelimit_state;
 242 extern int printk_ratelimit(void);
 243 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 244                                    unsigned int interval_msec);
 245 void log_buf_kexec_setup(void);
 246 #else
 247 static inline int vprintk(const char *s, va_list args)
 248         __attribute__ ((format (printf, 1, 0)));
 249 static inline int vprintk(const char *s, va_list args) { return 0; }
 250 static inline int printk(const char *s, ...)
 251         __attribute__ ((format (printf, 1, 2)));
 252 static inline int __cold printk(const char *s, ...) { return 0; }
 253 static inline int printk_ratelimit(void) { return 0; }
 254 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
 255                                           unsigned int interval_msec)   \
 256                 { return false; }
 257 static inline void log_buf_kexec_setup(void)
 258 {
 259 }
 260 #endif
 261
 262 extern int printk_needs_cpu(int cpu);
 263 extern void printk_tick(void);
 264
 265 extern void asmlinkage __attribute__((format(printf, 1, 2)))
 266         early_printk(const char *fmt, ...);
 267
 268 unsigned long int_sqrt(unsigned long);
 269
 270 static inline void console_silent(void)
 271 {
 272         console_loglevel = 0;
 273 }
 274
 275 static inline void console_verbose(void)
 276 {
 277         if (console_loglevel)
 278                 console_loglevel = 15;
 279 }
 280
 281 extern void bust_spinlocks(int yes);
 282 extern void wake_up_klogd(void);
 283 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 284 extern int panic_timeout;
 285 extern int panic_on_oops;
 286 extern int panic_on_unrecovered_nmi;
 287 extern const char *print_tainted(void);
 288 extern void add_taint(unsigned flag);
 289 extern int test_taint(unsigned flag);
 290 extern unsigned long get_taint(void);
 291 extern int root_mountflags;
 292
 293 /* Values used for system_state */
 294 extern enum system_states {
 295         SYSTEM_BOOTING,
 296         SYSTEM_RUNNING,
 297         SYSTEM_HALT,
 298         SYSTEM_POWER_OFF,
 299         SYSTEM_RESTART,
 300         SYSTEM_SUSPEND_DISK,
 301 } system_state;
 302
 303 #define TAINT_PROPRIETARY_MODULE        0
 304 #define TAINT_FORCED_MODULE             1
 305 #define TAINT_UNSAFE_SMP                2
 306 #define TAINT_FORCED_RMMOD              3
 307 #define TAINT_MACHINE_CHECK             4
 308 #define TAINT_BAD_PAGE                  5
 309 #define TAINT_USER                      6
 310 #define TAINT_DIE                       7
 311 #define TAINT_OVERRIDDEN_ACPI_TABLE     8
 312 #define TAINT_WARN                      9
 313 #define TAINT_CRAP                      10
 314
 315 extern void dump_stack(void) __cold;
 316
 317 enum {
 318         DUMP_PREFIX_NONE,
 319         DUMP_PREFIX_ADDRESS,
 320         DUMP_PREFIX_OFFSET
 321 };
 322 extern void hex_dump_to_buffer(const void *buf, size_t len,
 323                                 int rowsize, int groupsize,
 324                                 char *linebuf, size_t linebuflen, bool ascii);
 325 extern void print_hex_dump(const char *level, const char *prefix_str,
 326                                 int prefix_type, int rowsize, int groupsize,
 327                                 const void *buf, size_t len, bool ascii);
 328 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 329                         const void *buf, size_t len);
 330
 331 extern const char hex_asc[];
 332 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 333 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
 334
 335 static inline char *pack_hex_byte(char *buf, u8 byte)
 336 {
 337         *buf++ = hex_asc_hi(byte);
 338         *buf++ = hex_asc_lo(byte);
 339         return buf;
 340 }
 341
 342 #ifndef pr_fmt
 343 #define pr_fmt(fmt) fmt
 344 #endif
 345
 346 #define pr_emerg(fmt, ...) \
 347         printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
 348 #define pr_alert(fmt, ...) \
 349         printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
 350 #define pr_crit(fmt, ...) \
 351         printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
 352 #define pr_err(fmt, ...) \
 353         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
 354 #define pr_warning(fmt, ...) \
 355         printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
 356 #define pr_notice(fmt, ...) \
 357         printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
 358 #define pr_info(fmt, ...) \
 359         printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 360 #define pr_cont(fmt, ...) \
 361         printk(KERN_CONT fmt, ##__VA_ARGS__)
 362
 363 /* If you are writing a driver, please use dev_dbg instead */
 364 #if defined(DEBUG)
 365 #define pr_debug(fmt, ...) \
 366         printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
 367 #elif defined(CONFIG_DYNAMIC_DEBUG)
 368 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
 369 #define pr_debug(fmt, ...) do { \
 370         dynamic_pr_debug(fmt, ##__VA_ARGS__); \
 371         } while (0)
 372 #else
 373 #define pr_debug(fmt, ...) \
 374         ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
 375 #endif
 376
 377 /*
 378  *      Display an IP address in readable format.
 379  */
 380
 381 #define NIPQUAD(addr) \
 382         ((unsigned char *)&addr)[0], \
 383         ((unsigned char *)&addr)[1], \
 384         ((unsigned char *)&addr)[2], \
 385         ((unsigned char *)&addr)[3]
 386 #define NIPQUAD_FMT "%u.%u.%u.%u"
 387
 388 /*
 389  * min()/max()/clamp() macros that also do
 390  * strict type-checking.. See the
 391  * "unnecessary" pointer comparison.
 392  */
 393 #define min(x, y) ({                            \
 394         typeof(x) _min1 = (x);                  \
 395         typeof(y) _min2 = (y);                  \
 396         (void) (&_min1 == &_min2);              \
 397         _min1 < _min2 ? _min1 : _min2; })
 398
 399 #define max(x, y) ({                            \
 400         typeof(x) _max1 = (x);                  \
 401         typeof(y) _max2 = (y);                  \
 402         (void) (&_max1 == &_max2);              \
 403         _max1 > _max2 ? _max1 : _max2; })
 404
 405 /**
 406  * clamp - return a value clamped to a given range with strict typechecking
 407  * @val: current value
 408  * @min: minimum allowable value
 409  * @max: maximum allowable value
 410  *
 411  * This macro does strict typechecking of min/max to make sure they are of the
 412  * same type as val.  See the unnecessary pointer comparisons.
 413  */
 414 #define clamp(val, min, max) ({                 \
 415         typeof(val) __val = (val);              \
 416         typeof(min) __min = (min);              \
 417         typeof(max) __max = (max);              \
 418         (void) (&__val == &__min);              \
 419         (void) (&__val == &__max);              \
 420         __val = __val < __min ? __min: __val;   \
 421         __val > __max ? __max: __val; })
 422
 423 /*
 424  * ..and if you can't take the strict
 425  * types, you can specify one yourself.
 426  *
 427  * Or not use min/max/clamp at all, of course.
 428  */
 429 #define min_t(type, x, y) ({                    \
 430         type __min1 = (x);                      \
 431         type __min2 = (y);                      \
 432         __min1 < __min2 ? __min1: __min2; })
 433
 434 #define max_t(type, x, y) ({                    \
 435         type __max1 = (x);                      \
 436         type __max2 = (y);                      \
 437         __max1 > __max2 ? __max1: __max2; })
 438
 439 /**
 440  * clamp_t - return a value clamped to a given range using a given type
 441  * @type: the type of variable to use
 442  * @val: current value
 443  * @min: minimum allowable value
 444  * @max: maximum allowable value
 445  *
 446  * This macro does no typechecking and uses temporary variables of type
 447  * 'type' to make all the comparisons.
 448  */
 449 #define clamp_t(type, val, min, max) ({         \
 450         type __val = (val);                     \
 451         type __min = (min);                     \
 452         type __max = (max);                     \
 453         __val = __val < __min ? __min: __val;   \
 454         __val > __max ? __max: __val; })
 455
 456 /**
 457  * clamp_val - return a value clamped to a given range using val's type
 458  * @val: current value
 459  * @min: minimum allowable value
 460  * @max: maximum allowable value
 461  *
 462  * This macro does no typechecking and uses temporary variables of whatever
 463  * type the input argument 'val' is.  This is useful when val is an unsigned
 464  * type and min and max are literals that will otherwise be assigned a signed
 465  * integer type.
 466  */
 467 #define clamp_val(val, min, max) ({             \
 468         typeof(val) __val = (val);              \
 469         typeof(val) __min = (min);              \
 470         typeof(val) __max = (max);              \
 471         __val = __val < __min ? __min: __val;   \
 472         __val > __max ? __max: __val; })
 473
 474
 475 /*
 476  * swap - swap value of @a and @b
 477  */
 478 #define swap(a, b) \
 479         do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
 480
 481 /**
 482  * container_of - cast a member of a structure out to the containing structure
 483  * @ptr:        the pointer to the member.
 484  * @type:       the type of the container struct this is embedded in.
 485  * @member:     the name of the member within the struct.
 486  *
 487  */
 488 #define container_of(ptr, type, member) ({                      \
 489         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 490         (type *)( (char *)__mptr - offsetof(type,member) );})
 491
 492 struct sysinfo;
 493 extern int do_sysinfo(struct sysinfo *info);
 494
 495 #endif /* __KERNEL__ */
 496
 497 #define SI_LOAD_SHIFT   16
 498 struct sysinfo {
 499         long uptime;                    /* Seconds since boot */
 500         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 501         unsigned long totalram;         /* Total usable main memory size */
 502         unsigned long freeram;          /* Available memory size */
 503         unsigned long sharedram;        /* Amount of shared memory */
 504         unsigned long bufferram;        /* Memory used by buffers */
 505         unsigned long totalswap;        /* Total swap space size */
 506         unsigned long freeswap;         /* swap space still available */
 507         unsigned short procs;           /* Number of current processes */
 508         unsigned short pad;             /* explicit padding for m68k */
 509         unsigned long totalhigh;        /* Total high memory size */
 510         unsigned long freehigh;         /* Available high memory size */
 511         unsigned int mem_unit;          /* Memory unit size in bytes */
 512         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 513 };
 514
 515 /* Force a compilation error if condition is true */
 516 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 517
 518 /* Force a compilation error if condition is true, but also produce a
 519    result (of value 0 and type size_t), so the expression can be used
 520    e.g. in a structure initializer (or where-ever else comma expressions
 521    aren't permitted). */
 522 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 523
 524 /* Trap pasters of __FUNCTION__ at compile-time */
 525 #define __FUNCTION__ (__func__)
 526
 527 /* This helps us to avoid #ifdef CONFIG_NUMA */
 528 #ifdef CONFIG_NUMA
 529 #define NUMA_BUILD 1
 530 #else
 531 #define NUMA_BUILD 0
 532 #endif
 533
 534 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 535 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 536 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
 537 #endif
 538
 539 #endif