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_LBDAF 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 /* Use the default kernel loglevel */ 101 #define KERN_DEFAULT "<d>" 102 /* 103 * Annotation for a "continued" line of log printout (only done after a 104 * line that had no enclosing \n). Only to be used by core/arch code 105 * during early bootup (a continued line is not SMP-safe otherwise). 106 */ 107 #define KERN_CONT "<c>" 108 109 extern int console_printk[]; 110 111 #define console_loglevel (console_printk[0]) 112 #define default_message_loglevel (console_printk[1]) 113 #define minimum_console_loglevel (console_printk[2]) 114 #define default_console_loglevel (console_printk[3]) 115 116 struct completion; 117 struct pt_regs; 118 struct user; 119 120 #ifdef CONFIG_PREEMPT_VOLUNTARY 121 extern int _cond_resched(void); 122 # define might_resched() _cond_resched() 123 #else 124 # define might_resched() do { } while (0) 125 #endif 126 127 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP 128 void __might_sleep(char *file, int line); 129 /** 130 * might_sleep - annotation for functions that can sleep 131 * 132 * this macro will print a stack trace if it is executed in an atomic 133 * context (spinlock, irq-handler, ...). 134 * 135 * This is a useful debugging help to be able to catch problems early and not 136 * be bitten later when the calling function happens to sleep when it is not 137 * supposed to. 138 */ 139 # define might_sleep() \ 140 do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0) 141 #else 142 # define might_sleep() do { might_resched(); } while (0) 143 #endif 144 145 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 146 147 #define abs(x) ({ \ 148 int __x = (x); \ 149 (__x < 0) ? -__x : __x; \ 150 }) 151 152 #ifdef CONFIG_PROVE_LOCKING 153 void might_fault(void); 154 #else 155 static inline void might_fault(void) 156 { 157 might_sleep(); 158 } 159 #endif 160 161 extern struct atomic_notifier_head panic_notifier_list; 162 extern long (*panic_blink)(long time); 163 NORET_TYPE void panic(const char * fmt, ...) 164 __attribute__ ((NORET_AND format (printf, 1, 2))) __cold; 165 extern void oops_enter(void); 166 extern void oops_exit(void); 167 extern int oops_may_print(void); 168 NORET_TYPE void do_exit(long error_code) 169 ATTRIB_NORET; 170 NORET_TYPE void complete_and_exit(struct completion *, long) 171 ATTRIB_NORET; 172 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 173 extern long simple_strtol(const char *,char **,unsigned int); 174 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 175 extern long long simple_strtoll(const char *,char **,unsigned int); 176 extern int strict_strtoul(const char *, unsigned int, unsigned long *); 177 extern int strict_strtol(const char *, unsigned int, long *); 178 extern int strict_strtoull(const char *, unsigned int, unsigned long long *); 179 extern int strict_strtoll(const char *, unsigned int, long long *); 180 extern int sprintf(char * buf, const char * fmt, ...) 181 __attribute__ ((format (printf, 2, 3))); 182 extern int vsprintf(char *buf, const char *, va_list) 183 __attribute__ ((format (printf, 2, 0))); 184 extern int snprintf(char * buf, size_t size, const char * fmt, ...) 185 __attribute__ ((format (printf, 3, 4))); 186 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 187 __attribute__ ((format (printf, 3, 0))); 188 extern int scnprintf(char * buf, size_t size, const char * fmt, ...) 189 __attribute__ ((format (printf, 3, 4))); 190 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 191 __attribute__ ((format (printf, 3, 0))); 192 extern char *kasprintf(gfp_t gfp, const char *fmt, ...) 193 __attribute__ ((format (printf, 2, 3))); 194 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 195 196 extern int sscanf(const char *, const char *, ...) 197 __attribute__ ((format (scanf, 2, 3))); 198 extern int vsscanf(const char *, const char *, va_list) 199 __attribute__ ((format (scanf, 2, 0))); 200 201 extern int get_option(char **str, int *pint); 202 extern char *get_options(const char *str, int nints, int *ints); 203 extern unsigned long long memparse(const char *ptr, char **retptr); 204 205 extern int core_kernel_text(unsigned long addr); 206 extern int __kernel_text_address(unsigned long addr); 207 extern int kernel_text_address(unsigned long addr); 208 extern int func_ptr_is_kernel_text(void *ptr); 209 210 struct pid; 211 extern struct pid *session_of_pgrp(struct pid *pgrp); 212 213 /* 214 * FW_BUG 215 * Add this to a message where you are sure the firmware is buggy or behaves 216 * really stupid or out of spec. Be aware that the responsible BIOS developer 217 * should be able to fix this issue or at least get a concrete idea of the 218 * problem by reading your message without the need of looking at the kernel 219 * code. 220 * 221 * Use it for definite and high priority BIOS bugs. 222 * 223 * FW_WARN 224 * Use it for not that clear (e.g. could the kernel messed up things already?) 225 * and medium priority BIOS bugs. 226 * 227 * FW_INFO 228 * Use this one if you want to tell the user or vendor about something 229 * suspicious, but generally harmless related to the firmware. 230 * 231 * Use it for information or very low priority BIOS bugs. 232 */ 233 #define FW_BUG "[Firmware Bug]: " 234 #define FW_WARN "[Firmware Warn]: " 235 #define FW_INFO "[Firmware Info]: " 236 237 #ifdef CONFIG_PRINTK 238 asmlinkage int vprintk(const char *fmt, va_list args) 239 __attribute__ ((format (printf, 1, 0))); 240 asmlinkage int printk(const char * fmt, ...) 241 __attribute__ ((format (printf, 1, 2))) __cold; 242 243 extern struct ratelimit_state printk_ratelimit_state; 244 extern int printk_ratelimit(void); 245 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies, 246 unsigned int interval_msec); 247 248 /* 249 * Print a one-time message (analogous to WARN_ONCE() et al): 250 */ 251 #define printk_once(x...) ({ \ 252 static int __print_once = 1; \ 253 \ 254 if (__print_once) { \ 255 __print_once = 0; \ 256 printk(x); \ 257 } \ 258 }) 259 260 void log_buf_kexec_setup(void); 261 #else 262 static inline int vprintk(const char *s, va_list args) 263 __attribute__ ((format (printf, 1, 0))); 264 static inline int vprintk(const char *s, va_list args) { return 0; } 265 static inline int printk(const char *s, ...) 266 __attribute__ ((format (printf, 1, 2))); 267 static inline int __cold printk(const char *s, ...) { return 0; } 268 static inline int printk_ratelimit(void) { return 0; } 269 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \ 270 unsigned int interval_msec) \ 271 { return false; } 272 273 /* No effect, but we still get type checking even in the !PRINTK case: */ 274 #define printk_once(x...) printk(x) 275 276 static inline void log_buf_kexec_setup(void) 277 { 278 } 279 #endif 280 281 extern int printk_needs_cpu(int cpu); 282 extern void printk_tick(void); 283 284 extern void asmlinkage __attribute__((format(printf, 1, 2))) 285 early_printk(const char *fmt, ...); 286 287 unsigned long int_sqrt(unsigned long); 288 289 static inline void console_silent(void) 290 { 291 console_loglevel = 0; 292 } 293 294 static inline void console_verbose(void) 295 { 296 if (console_loglevel) 297 console_loglevel = 15; 298 } 299 300 extern void bust_spinlocks(int yes); 301 extern void wake_up_klogd(void); 302 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 303 extern int panic_timeout; 304 extern int panic_on_oops; 305 extern int panic_on_unrecovered_nmi; 306 extern int panic_on_io_nmi; 307 extern const char *print_tainted(void); 308 extern void add_taint(unsigned flag); 309 extern int test_taint(unsigned flag); 310 extern unsigned long get_taint(void); 311 extern int root_mountflags; 312 313 /* Values used for system_state */ 314 extern enum system_states { 315 SYSTEM_BOOTING, 316 SYSTEM_RUNNING, 317 SYSTEM_HALT, 318 SYSTEM_POWER_OFF, 319 SYSTEM_RESTART, 320 SYSTEM_SUSPEND_DISK, 321 } system_state; 322 323 #define TAINT_PROPRIETARY_MODULE 0 324 #define TAINT_FORCED_MODULE 1 325 #define TAINT_UNSAFE_SMP 2 326 #define TAINT_FORCED_RMMOD 3 327 #define TAINT_MACHINE_CHECK 4 328 #define TAINT_BAD_PAGE 5 329 #define TAINT_USER 6 330 #define TAINT_DIE 7 331 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 332 #define TAINT_WARN 9 333 #define TAINT_CRAP 10 334 335 extern void dump_stack(void) __cold; 336 337 enum { 338 DUMP_PREFIX_NONE, 339 DUMP_PREFIX_ADDRESS, 340 DUMP_PREFIX_OFFSET 341 }; 342 extern void hex_dump_to_buffer(const void *buf, size_t len, 343 int rowsize, int groupsize, 344 char *linebuf, size_t linebuflen, bool ascii); 345 extern void print_hex_dump(const char *level, const char *prefix_str, 346 int prefix_type, int rowsize, int groupsize, 347 const void *buf, size_t len, bool ascii); 348 extern void print_hex_dump_bytes(const char *prefix_str, int prefix_type, 349 const void *buf, size_t len); 350 351 extern const char hex_asc[]; 352 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 353 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 354 355 static inline char *pack_hex_byte(char *buf, u8 byte) 356 { 357 *buf++ = hex_asc_hi(byte); 358 *buf++ = hex_asc_lo(byte); 359 return buf; 360 } 361 362 #ifndef pr_fmt 363 #define pr_fmt(fmt) fmt 364 #endif 365 366 #define pr_emerg(fmt, ...) \ 367 printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__) 368 #define pr_alert(fmt, ...) \ 369 printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__) 370 #define pr_crit(fmt, ...) \ 371 printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__) 372 #define pr_err(fmt, ...) \ 373 printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__) 374 #define pr_warning(fmt, ...) \ 375 printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__) 376 #define pr_notice(fmt, ...) \ 377 printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__) 378 #define pr_info(fmt, ...) \ 379 printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__) 380 #define pr_cont(fmt, ...) \ 381 printk(KERN_CONT fmt, ##__VA_ARGS__) 382 383 /* pr_devel() should produce zero code unless DEBUG is defined */ 384 #ifdef DEBUG 385 #define pr_devel(fmt, ...) \ 386 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) 387 #else 388 #define pr_devel(fmt, ...) \ 389 ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; }) 390 #endif 391 392 /* If you are writing a driver, please use dev_dbg instead */ 393 #if defined(DEBUG) 394 #define pr_debug(fmt, ...) \ 395 printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) 396 #elif defined(CONFIG_DYNAMIC_DEBUG) 397 /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */ 398 #define pr_debug(fmt, ...) do { \ 399 dynamic_pr_debug(fmt, ##__VA_ARGS__); \ 400 } while (0) 401 #else 402 #define pr_debug(fmt, ...) \ 403 ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; }) 404 #endif 405 406 /* 407 * General tracing related utility functions - trace_printk(), 408 * tracing_on/tracing_off and tracing_start()/tracing_stop 409 * 410 * Use tracing_on/tracing_off when you want to quickly turn on or off 411 * tracing. It simply enables or disables the recording of the trace events. 412 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 413 * file, which gives a means for the kernel and userspace to interact. 414 * Place a tracing_off() in the kernel where you want tracing to end. 415 * From user space, examine the trace, and then echo 1 > tracing_on 416 * to continue tracing. 417 * 418 * tracing_stop/tracing_start has slightly more overhead. It is used 419 * by things like suspend to ram where disabling the recording of the 420 * trace is not enough, but tracing must actually stop because things 421 * like calling smp_processor_id() may crash the system. 422 * 423 * Most likely, you want to use tracing_on/tracing_off. 424 */ 425 #ifdef CONFIG_RING_BUFFER 426 void tracing_on(void); 427 void tracing_off(void); 428 /* trace_off_permanent stops recording with no way to bring it back */ 429 void tracing_off_permanent(void); 430 int tracing_is_on(void); 431 #else 432 static inline void tracing_on(void) { } 433 static inline void tracing_off(void) { } 434 static inline void tracing_off_permanent(void) { } 435 static inline int tracing_is_on(void) { return 0; } 436 #endif 437 #ifdef CONFIG_TRACING 438 extern void tracing_start(void); 439 extern void tracing_stop(void); 440 extern void ftrace_off_permanent(void); 441 442 extern void 443 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3); 444 445 static inline void __attribute__ ((format (printf, 1, 2))) 446 ____trace_printk_check_format(const char *fmt, ...) 447 { 448 } 449 #define __trace_printk_check_format(fmt, args...) \ 450 do { \ 451 if (0) \ 452 ____trace_printk_check_format(fmt, ##args); \ 453 } while (0) 454 455 /** 456 * trace_printk - printf formatting in the ftrace buffer 457 * @fmt: the printf format for printing 458 * 459 * Note: __trace_printk is an internal function for trace_printk and 460 * the @ip is passed in via the trace_printk macro. 461 * 462 * This function allows a kernel developer to debug fast path sections 463 * that printk is not appropriate for. By scattering in various 464 * printk like tracing in the code, a developer can quickly see 465 * where problems are occurring. 466 * 467 * This is intended as a debugging tool for the developer only. 468 * Please refrain from leaving trace_printks scattered around in 469 * your code. 470 */ 471 472 #define trace_printk(fmt, args...) \ 473 do { \ 474 __trace_printk_check_format(fmt, ##args); \ 475 if (__builtin_constant_p(fmt)) { \ 476 static const char *trace_printk_fmt \ 477 __attribute__((section("__trace_printk_fmt"))) = \ 478 __builtin_constant_p(fmt) ? fmt : NULL; \ 479 \ 480 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 481 } else \ 482 __trace_printk(_THIS_IP_, fmt, ##args); \ 483 } while (0) 484 485 extern int 486 __trace_bprintk(unsigned long ip, const char *fmt, ...) 487 __attribute__ ((format (printf, 2, 3))); 488 489 extern int 490 __trace_printk(unsigned long ip, const char *fmt, ...) 491 __attribute__ ((format (printf, 2, 3))); 492 493 /* 494 * The double __builtin_constant_p is because gcc will give us an error 495 * if we try to allocate the static variable to fmt if it is not a 496 * constant. Even with the outer if statement. 497 */ 498 #define ftrace_vprintk(fmt, vargs) \ 499 do { \ 500 if (__builtin_constant_p(fmt)) { \ 501 static const char *trace_printk_fmt \ 502 __attribute__((section("__trace_printk_fmt"))) = \ 503 __builtin_constant_p(fmt) ? fmt : NULL; \ 504 \ 505 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 506 } else \ 507 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 508 } while (0) 509 510 extern int 511 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 512 513 extern int 514 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 515 516 extern void ftrace_dump(void); 517 #else 518 static inline void 519 ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { } 520 static inline int 521 trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2))); 522 523 static inline void tracing_start(void) { } 524 static inline void tracing_stop(void) { } 525 static inline void ftrace_off_permanent(void) { } 526 static inline int 527 trace_printk(const char *fmt, ...) 528 { 529 return 0; 530 } 531 static inline int 532 ftrace_vprintk(const char *fmt, va_list ap) 533 { 534 return 0; 535 } 536 static inline void ftrace_dump(void) { } 537 #endif /* CONFIG_TRACING */ 538 539 /* 540 * Display an IP address in readable format. 541 */ 542 543 #define NIPQUAD(addr) \ 544 ((unsigned char *)&addr)[0], \ 545 ((unsigned char *)&addr)[1], \ 546 ((unsigned char *)&addr)[2], \ 547 ((unsigned char *)&addr)[3] 548 #define NIPQUAD_FMT "%u.%u.%u.%u" 549 550 /* 551 * min()/max()/clamp() macros that also do 552 * strict type-checking.. See the 553 * "unnecessary" pointer comparison. 554 */ 555 #define min(x, y) ({ \ 556 typeof(x) _min1 = (x); \ 557 typeof(y) _min2 = (y); \ 558 (void) (&_min1 == &_min2); \ 559 _min1 < _min2 ? _min1 : _min2; }) 560 561 #define max(x, y) ({ \ 562 typeof(x) _max1 = (x); \ 563 typeof(y) _max2 = (y); \ 564 (void) (&_max1 == &_max2); \ 565 _max1 > _max2 ? _max1 : _max2; }) 566 567 /** 568 * clamp - return a value clamped to a given range with strict typechecking 569 * @val: current value 570 * @min: minimum allowable value 571 * @max: maximum allowable value 572 * 573 * This macro does strict typechecking of min/max to make sure they are of the 574 * same type as val. See the unnecessary pointer comparisons. 575 */ 576 #define clamp(val, min, max) ({ \ 577 typeof(val) __val = (val); \ 578 typeof(min) __min = (min); \ 579 typeof(max) __max = (max); \ 580 (void) (&__val == &__min); \ 581 (void) (&__val == &__max); \ 582 __val = __val < __min ? __min: __val; \ 583 __val > __max ? __max: __val; }) 584 585 /* 586 * ..and if you can't take the strict 587 * types, you can specify one yourself. 588 * 589 * Or not use min/max/clamp at all, of course. 590 */ 591 #define min_t(type, x, y) ({ \ 592 type __min1 = (x); \ 593 type __min2 = (y); \ 594 __min1 < __min2 ? __min1: __min2; }) 595 596 #define max_t(type, x, y) ({ \ 597 type __max1 = (x); \ 598 type __max2 = (y); \ 599 __max1 > __max2 ? __max1: __max2; }) 600 601 /** 602 * clamp_t - return a value clamped to a given range using a given type 603 * @type: the type of variable to use 604 * @val: current value 605 * @min: minimum allowable value 606 * @max: maximum allowable value 607 * 608 * This macro does no typechecking and uses temporary variables of type 609 * 'type' to make all the comparisons. 610 */ 611 #define clamp_t(type, val, min, max) ({ \ 612 type __val = (val); \ 613 type __min = (min); \ 614 type __max = (max); \ 615 __val = __val < __min ? __min: __val; \ 616 __val > __max ? __max: __val; }) 617 618 /** 619 * clamp_val - return a value clamped to a given range using val's type 620 * @val: current value 621 * @min: minimum allowable value 622 * @max: maximum allowable value 623 * 624 * This macro does no typechecking and uses temporary variables of whatever 625 * type the input argument 'val' is. This is useful when val is an unsigned 626 * type and min and max are literals that will otherwise be assigned a signed 627 * integer type. 628 */ 629 #define clamp_val(val, min, max) ({ \ 630 typeof(val) __val = (val); \ 631 typeof(val) __min = (min); \ 632 typeof(val) __max = (max); \ 633 __val = __val < __min ? __min: __val; \ 634 __val > __max ? __max: __val; }) 635 636 637 /* 638 * swap - swap value of @a and @b 639 */ 640 #define swap(a, b) \ 641 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 642 643 /** 644 * container_of - cast a member of a structure out to the containing structure 645 * @ptr: the pointer to the member. 646 * @type: the type of the container struct this is embedded in. 647 * @member: the name of the member within the struct. 648 * 649 */ 650 #define container_of(ptr, type, member) ({ \ 651 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 652 (type *)( (char *)__mptr - offsetof(type,member) );}) 653 654 struct sysinfo; 655 extern int do_sysinfo(struct sysinfo *info); 656 657 #endif /* __KERNEL__ */ 658 659 #define SI_LOAD_SHIFT 16 660 struct sysinfo { 661 long uptime; /* Seconds since boot */ 662 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */ 663 unsigned long totalram; /* Total usable main memory size */ 664 unsigned long freeram; /* Available memory size */ 665 unsigned long sharedram; /* Amount of shared memory */ 666 unsigned long bufferram; /* Memory used by buffers */ 667 unsigned long totalswap; /* Total swap space size */ 668 unsigned long freeswap; /* swap space still available */ 669 unsigned short procs; /* Number of current processes */ 670 unsigned short pad; /* explicit padding for m68k */ 671 unsigned long totalhigh; /* Total high memory size */ 672 unsigned long freehigh; /* Available high memory size */ 673 unsigned int mem_unit; /* Memory unit size in bytes */ 674 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */ 675 }; 676 677 /* Force a compilation error if condition is true */ 678 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 679 680 /* Force a compilation error if condition is true, but also produce a 681 result (of value 0 and type size_t), so the expression can be used 682 e.g. in a structure initializer (or where-ever else comma expressions 683 aren't permitted). */ 684 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1) 685 686 /* Trap pasters of __FUNCTION__ at compile-time */ 687 #define __FUNCTION__ (__func__) 688 689 /* This helps us to avoid #ifdef CONFIG_NUMA */ 690 #ifdef CONFIG_NUMA 691 #define NUMA_BUILD 1 692 #else 693 #define NUMA_BUILD 0 694 #endif 695 696 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 697 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 698 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 699 #endif 700 701 #endif 702