1#ifndef _LINUX_KERNEL_H 2#define _LINUX_KERNEL_H 3 4/* 5 * 'kernel.h' contains some often-used function prototypes etc 6 */ 7#define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1) 8#define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask)) 9 10#ifdef __KERNEL__ 11 12#include <stdarg.h> 13#include <linux/linkage.h> 14#include <linux/stddef.h> 15#include <linux/types.h> 16#include <linux/compiler.h> 17#include <linux/bitops.h> 18#include <linux/log2.h> 19#include <linux/typecheck.h> 20#include <linux/printk.h> 21#include <linux/dynamic_debug.h> 22#include <asm/byteorder.h> 23#include <asm/bug.h> 24 25#define USHRT_MAX ((u16)(~0U)) 26#define SHRT_MAX ((s16)(USHRT_MAX>>1)) 27#define SHRT_MIN ((s16)(-SHRT_MAX - 1)) 28#define INT_MAX ((int)(~0U>>1)) 29#define INT_MIN (-INT_MAX - 1) 30#define UINT_MAX (~0U) 31#define LONG_MAX ((long)(~0UL>>1)) 32#define LONG_MIN (-LONG_MAX - 1) 33#define ULONG_MAX (~0UL) 34#define LLONG_MAX ((long long)(~0ULL>>1)) 35#define LLONG_MIN (-LLONG_MAX - 1) 36#define ULLONG_MAX (~0ULL) 37 38#define STACK_MAGIC 0xdeadbeef 39 40#define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) 41#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) 42#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) 43#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) 44 45#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) 46 47/* 48 * This looks more complex than it should be. But we need to 49 * get the type for the ~ right in round_down (it needs to be 50 * as wide as the result!), and we want to evaluate the macro 51 * arguments just once each. 52 */ 53#define __round_mask(x, y) ((__typeof__(x))((y)-1)) 54#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 55#define round_down(x, y) ((x) & ~__round_mask(x, y)) 56 57#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) 58#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) 59 60/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */ 61#define roundup(x, y) ( \ 62{ \ 63 const typeof(y) __y = y; \ 64 (((x) + (__y - 1)) / __y) * __y; \ 65} \ 66) 67#define rounddown(x, y) ( \ 68{ \ 69 typeof(x) __x = (x); \ 70 __x - (__x % (y)); \ 71} \ 72) 73#define DIV_ROUND_CLOSEST(x, divisor)( \ 74{ \ 75 typeof(divisor) __divisor = divisor; \ 76 (((x) + ((__divisor) / 2)) / (__divisor)); \ 77} \ 78) 79 80#define _RET_IP_ (unsigned long)__builtin_return_address(0) 81#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 82 83#ifdef CONFIG_LBDAF 84# include <asm/div64.h> 85# define sector_div(a, b) do_div(a, b) 86#else 87# define sector_div(n, b)( \ 88{ \ 89 int _res; \ 90 _res = (n) % (b); \ 91 (n) /= (b); \ 92 _res; \ 93} \ 94) 95#endif 96 97/** 98 * upper_32_bits - return bits 32-63 of a number 99 * @n: the number we're accessing 100 * 101 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 102 * the "right shift count >= width of type" warning when that quantity is 103 * 32-bits. 104 */ 105#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 106 107/** 108 * lower_32_bits - return bits 0-31 of a number 109 * @n: the number we're accessing 110 */ 111#define lower_32_bits(n) ((u32)(n)) 112 113struct completion; 114struct pt_regs; 115struct user; 116 117#ifdef CONFIG_PREEMPT_VOLUNTARY 118extern int _cond_resched(void); 119# define might_resched() _cond_resched() 120#else 121# define might_resched() do { } while (0) 122#endif 123 124#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP 125 void __might_sleep(const char *file, int line, int preempt_offset); 126/** 127 * might_sleep - annotation for functions that can sleep 128 * 129 * this macro will print a stack trace if it is executed in an atomic 130 * context (spinlock, irq-handler, ...). 131 * 132 * This is a useful debugging help to be able to catch problems early and not 133 * be bitten later when the calling function happens to sleep when it is not 134 * supposed to. 135 */ 136# define might_sleep() \ 137 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 138#else 139 static inline void __might_sleep(const char *file, int line, 140 int preempt_offset) { } 141# define might_sleep() do { might_resched(); } while (0) 142#endif 143 144#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 145 146/* 147 * abs() handles unsigned and signed longs, ints, shorts and chars. For all 148 * input types abs() returns a signed long. 149 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64() 150 * for those. 151 */ 152#define abs(x) ({ \ 153 long ret; \ 154 if (sizeof(x) == sizeof(long)) { \ 155 long __x = (x); \ 156 ret = (__x < 0) ? -__x : __x; \ 157 } else { \ 158 int __x = (x); \ 159 ret = (__x < 0) ? -__x : __x; \ 160 } \ 161 ret; \ 162 }) 163 164#define abs64(x) ({ \ 165 s64 __x = (x); \ 166 (__x < 0) ? -__x : __x; \ 167 }) 168 169#ifdef CONFIG_PROVE_LOCKING 170void might_fault(void); 171#else 172static inline void might_fault(void) 173{ 174 might_sleep(); 175} 176#endif 177 178extern struct atomic_notifier_head panic_notifier_list; 179extern long (*panic_blink)(int state); 180NORET_TYPE void panic(const char * fmt, ...) 181 __attribute__ ((NORET_AND format (printf, 1, 2))) __cold; 182extern void oops_enter(void); 183extern void oops_exit(void); 184void print_oops_end_marker(void); 185extern int oops_may_print(void); 186NORET_TYPE void do_exit(long error_code) 187 ATTRIB_NORET; 188NORET_TYPE void complete_and_exit(struct completion *, long) 189 ATTRIB_NORET; 190 191/* Internal, do not use. */ 192int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 193int __must_check _kstrtol(const char *s, unsigned int base, long *res); 194 195int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 196int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 197static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 198{ 199 /* 200 * We want to shortcut function call, but 201 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 202 */ 203 if (sizeof(unsigned long) == sizeof(unsigned long long) && 204 __alignof__(unsigned long) == __alignof__(unsigned long long)) 205 return kstrtoull(s, base, (unsigned long long *)res); 206 else 207 return _kstrtoul(s, base, res); 208} 209 210static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 211{ 212 /* 213 * We want to shortcut function call, but 214 * __builtin_types_compatible_p(long, long long) = 0. 215 */ 216 if (sizeof(long) == sizeof(long long) && 217 __alignof__(long) == __alignof__(long long)) 218 return kstrtoll(s, base, (long long *)res); 219 else 220 return _kstrtol(s, base, res); 221} 222 223int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 224int __must_check kstrtoint(const char *s, unsigned int base, int *res); 225 226static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 227{ 228 return kstrtoull(s, base, res); 229} 230 231static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 232{ 233 return kstrtoll(s, base, res); 234} 235 236static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 237{ 238 return kstrtouint(s, base, res); 239} 240 241static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 242{ 243 return kstrtoint(s, base, res); 244} 245 246int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 247int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 248int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 249int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 250 251extern unsigned long simple_strtoul(const char *,char **,unsigned int); 252extern long simple_strtol(const char *,char **,unsigned int); 253extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 254extern long long simple_strtoll(const char *,char **,unsigned int); 255#define strict_strtoul kstrtoul 256#define strict_strtol kstrtol 257#define strict_strtoull kstrtoull 258#define strict_strtoll kstrtoll 259 260extern int sprintf(char * buf, const char * fmt, ...) 261 __attribute__ ((format (printf, 2, 3))); 262extern int vsprintf(char *buf, const char *, va_list) 263 __attribute__ ((format (printf, 2, 0))); 264extern int snprintf(char * buf, size_t size, const char * fmt, ...) 265 __attribute__ ((format (printf, 3, 4))); 266extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 267 __attribute__ ((format (printf, 3, 0))); 268extern int scnprintf(char * buf, size_t size, const char * fmt, ...) 269 __attribute__ ((format (printf, 3, 4))); 270extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 271 __attribute__ ((format (printf, 3, 0))); 272extern char *kasprintf(gfp_t gfp, const char *fmt, ...) 273 __attribute__ ((format (printf, 2, 3))); 274extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 275 276extern int sscanf(const char *, const char *, ...) 277 __attribute__ ((format (scanf, 2, 3))); 278extern int vsscanf(const char *, const char *, va_list) 279 __attribute__ ((format (scanf, 2, 0))); 280 281extern int get_option(char **str, int *pint); 282extern char *get_options(const char *str, int nints, int *ints); 283extern unsigned long long memparse(const char *ptr, char **retptr); 284 285extern int core_kernel_text(unsigned long addr); 286extern int __kernel_text_address(unsigned long addr); 287extern int kernel_text_address(unsigned long addr); 288extern int func_ptr_is_kernel_text(void *ptr); 289 290struct pid; 291extern struct pid *session_of_pgrp(struct pid *pgrp); 292 293unsigned long int_sqrt(unsigned long); 294 295extern void bust_spinlocks(int yes); 296extern void wake_up_klogd(void); 297extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 298extern int panic_timeout; 299extern int panic_on_oops; 300extern int panic_on_unrecovered_nmi; 301extern int panic_on_io_nmi; 302extern const char *print_tainted(void); 303extern void add_taint(unsigned flag); 304extern int test_taint(unsigned flag); 305extern unsigned long get_taint(void); 306extern int root_mountflags; 307 308extern bool early_boot_irqs_disabled; 309 310/* Values used for system_state */ 311extern enum system_states { 312 SYSTEM_BOOTING, 313 SYSTEM_RUNNING, 314 SYSTEM_HALT, 315 SYSTEM_POWER_OFF, 316 SYSTEM_RESTART, 317 SYSTEM_SUSPEND_DISK, 318} system_state; 319 320#define TAINT_PROPRIETARY_MODULE 0 321#define TAINT_FORCED_MODULE 1 322#define TAINT_UNSAFE_SMP 2 323#define TAINT_FORCED_RMMOD 3 324#define TAINT_MACHINE_CHECK 4 325#define TAINT_BAD_PAGE 5 326#define TAINT_USER 6 327#define TAINT_DIE 7 328#define TAINT_OVERRIDDEN_ACPI_TABLE 8 329#define TAINT_WARN 9 330#define TAINT_CRAP 10 331#define TAINT_FIRMWARE_WORKAROUND 11 332 333extern const char hex_asc[]; 334#define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 335#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 336 337static inline char *pack_hex_byte(char *buf, u8 byte) 338{ 339 *buf++ = hex_asc_hi(byte); 340 *buf++ = hex_asc_lo(byte); 341 return buf; 342} 343 344extern int hex_to_bin(char ch); 345extern void hex2bin(u8 *dst, const char *src, size_t count); 346 347/* 348 * General tracing related utility functions - trace_printk(), 349 * tracing_on/tracing_off and tracing_start()/tracing_stop 350 * 351 * Use tracing_on/tracing_off when you want to quickly turn on or off 352 * tracing. It simply enables or disables the recording of the trace events. 353 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 354 * file, which gives a means for the kernel and userspace to interact. 355 * Place a tracing_off() in the kernel where you want tracing to end. 356 * From user space, examine the trace, and then echo 1 > tracing_on 357 * to continue tracing. 358 * 359 * tracing_stop/tracing_start has slightly more overhead. It is used 360 * by things like suspend to ram where disabling the recording of the 361 * trace is not enough, but tracing must actually stop because things 362 * like calling smp_processor_id() may crash the system. 363 * 364 * Most likely, you want to use tracing_on/tracing_off. 365 */ 366#ifdef CONFIG_RING_BUFFER 367void tracing_on(void); 368void tracing_off(void); 369/* trace_off_permanent stops recording with no way to bring it back */ 370void tracing_off_permanent(void); 371int tracing_is_on(void); 372#else 373static inline void tracing_on(void) { } 374static inline void tracing_off(void) { } 375static inline void tracing_off_permanent(void) { } 376static inline int tracing_is_on(void) { return 0; } 377#endif 378 379enum ftrace_dump_mode { 380 DUMP_NONE, 381 DUMP_ALL, 382 DUMP_ORIG, 383}; 384 385#ifdef CONFIG_TRACING 386extern void tracing_start(void); 387extern void tracing_stop(void); 388extern void ftrace_off_permanent(void); 389 390static inline void __attribute__ ((format (printf, 1, 2))) 391____trace_printk_check_format(const char *fmt, ...) 392{ 393} 394#define __trace_printk_check_format(fmt, args...) \ 395do { \ 396 if (0) \ 397 ____trace_printk_check_format(fmt, ##args); \ 398} while (0) 399 400/** 401 * trace_printk - printf formatting in the ftrace buffer 402 * @fmt: the printf format for printing 403 * 404 * Note: __trace_printk is an internal function for trace_printk and 405 * the @ip is passed in via the trace_printk macro. 406 * 407 * This function allows a kernel developer to debug fast path sections 408 * that printk is not appropriate for. By scattering in various 409 * printk like tracing in the code, a developer can quickly see 410 * where problems are occurring. 411 * 412 * This is intended as a debugging tool for the developer only. 413 * Please refrain from leaving trace_printks scattered around in 414 * your code. 415 */ 416 417#define trace_printk(fmt, args...) \ 418do { \ 419 __trace_printk_check_format(fmt, ##args); \ 420 if (__builtin_constant_p(fmt)) { \ 421 static const char *trace_printk_fmt \ 422 __attribute__((section("__trace_printk_fmt"))) = \ 423 __builtin_constant_p(fmt) ? fmt : NULL; \ 424 \ 425 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 426 } else \ 427 __trace_printk(_THIS_IP_, fmt, ##args); \ 428} while (0) 429 430extern int 431__trace_bprintk(unsigned long ip, const char *fmt, ...) 432 __attribute__ ((format (printf, 2, 3))); 433 434extern int 435__trace_printk(unsigned long ip, const char *fmt, ...) 436 __attribute__ ((format (printf, 2, 3))); 437 438extern void trace_dump_stack(void); 439 440/* 441 * The double __builtin_constant_p is because gcc will give us an error 442 * if we try to allocate the static variable to fmt if it is not a 443 * constant. Even with the outer if statement. 444 */ 445#define ftrace_vprintk(fmt, vargs) \ 446do { \ 447 if (__builtin_constant_p(fmt)) { \ 448 static const char *trace_printk_fmt \ 449 __attribute__((section("__trace_printk_fmt"))) = \ 450 __builtin_constant_p(fmt) ? fmt : NULL; \ 451 \ 452 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 453 } else \ 454 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 455} while (0) 456 457extern int 458__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 459 460extern int 461__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 462 463extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 464#else 465static inline int 466trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2))); 467 468static inline void tracing_start(void) { } 469static inline void tracing_stop(void) { } 470static inline void ftrace_off_permanent(void) { } 471static inline void trace_dump_stack(void) { } 472static inline int 473trace_printk(const char *fmt, ...) 474{ 475 return 0; 476} 477static inline int 478ftrace_vprintk(const char *fmt, va_list ap) 479{ 480 return 0; 481} 482static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 483#endif /* CONFIG_TRACING */ 484 485/* 486 * min()/max()/clamp() macros that also do 487 * strict type-checking.. See the 488 * "unnecessary" pointer comparison. 489 */ 490#define min(x, y) ({ \ 491 typeof(x) _min1 = (x); \ 492 typeof(y) _min2 = (y); \ 493 (void) (&_min1 == &_min2); \ 494 _min1 < _min2 ? _min1 : _min2; }) 495 496#define max(x, y) ({ \ 497 typeof(x) _max1 = (x); \ 498 typeof(y) _max2 = (y); \ 499 (void) (&_max1 == &_max2); \ 500 _max1 > _max2 ? _max1 : _max2; }) 501 502#define min3(x, y, z) ({ \ 503 typeof(x) _min1 = (x); \ 504 typeof(y) _min2 = (y); \ 505 typeof(z) _min3 = (z); \ 506 (void) (&_min1 == &_min2); \ 507 (void) (&_min1 == &_min3); \ 508 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \ 509 (_min2 < _min3 ? _min2 : _min3); }) 510 511#define max3(x, y, z) ({ \ 512 typeof(x) _max1 = (x); \ 513 typeof(y) _max2 = (y); \ 514 typeof(z) _max3 = (z); \ 515 (void) (&_max1 == &_max2); \ 516 (void) (&_max1 == &_max3); \ 517 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \ 518 (_max2 > _max3 ? _max2 : _max3); }) 519 520/** 521 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 522 * @x: value1 523 * @y: value2 524 */ 525#define min_not_zero(x, y) ({ \ 526 typeof(x) __x = (x); \ 527 typeof(y) __y = (y); \ 528 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 529 530/** 531 * clamp - return a value clamped to a given range with strict typechecking 532 * @val: current value 533 * @min: minimum allowable value 534 * @max: maximum allowable value 535 * 536 * This macro does strict typechecking of min/max to make sure they are of the 537 * same type as val. See the unnecessary pointer comparisons. 538 */ 539#define clamp(val, min, max) ({ \ 540 typeof(val) __val = (val); \ 541 typeof(min) __min = (min); \ 542 typeof(max) __max = (max); \ 543 (void) (&__val == &__min); \ 544 (void) (&__val == &__max); \ 545 __val = __val < __min ? __min: __val; \ 546 __val > __max ? __max: __val; }) 547 548/* 549 * ..and if you can't take the strict 550 * types, you can specify one yourself. 551 * 552 * Or not use min/max/clamp at all, of course. 553 */ 554#define min_t(type, x, y) ({ \ 555 type __min1 = (x); \ 556 type __min2 = (y); \ 557 __min1 < __min2 ? __min1: __min2; }) 558 559#define max_t(type, x, y) ({ \ 560 type __max1 = (x); \ 561 type __max2 = (y); \ 562 __max1 > __max2 ? __max1: __max2; }) 563 564/** 565 * clamp_t - return a value clamped to a given range using a given type 566 * @type: the type of variable to use 567 * @val: current value 568 * @min: minimum allowable value 569 * @max: maximum allowable value 570 * 571 * This macro does no typechecking and uses temporary variables of type 572 * 'type' to make all the comparisons. 573 */ 574#define clamp_t(type, val, min, max) ({ \ 575 type __val = (val); \ 576 type __min = (min); \ 577 type __max = (max); \ 578 __val = __val < __min ? __min: __val; \ 579 __val > __max ? __max: __val; }) 580 581/** 582 * clamp_val - return a value clamped to a given range using val's type 583 * @val: current value 584 * @min: minimum allowable value 585 * @max: maximum allowable value 586 * 587 * This macro does no typechecking and uses temporary variables of whatever 588 * type the input argument 'val' is. This is useful when val is an unsigned 589 * type and min and max are literals that will otherwise be assigned a signed 590 * integer type. 591 */ 592#define clamp_val(val, min, max) ({ \ 593 typeof(val) __val = (val); \ 594 typeof(val) __min = (min); \ 595 typeof(val) __max = (max); \ 596 __val = __val < __min ? __min: __val; \ 597 __val > __max ? __max: __val; }) 598 599 600/* 601 * swap - swap value of @a and @b 602 */ 603#define swap(a, b) \ 604 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 605 606/** 607 * container_of - cast a member of a structure out to the containing structure 608 * @ptr: the pointer to the member. 609 * @type: the type of the container struct this is embedded in. 610 * @member: the name of the member within the struct. 611 * 612 */ 613#define container_of(ptr, type, member) ({ \ 614 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 615 (type *)( (char *)__mptr - offsetof(type,member) );}) 616 617struct sysinfo; 618extern int do_sysinfo(struct sysinfo *info); 619 620#endif /* __KERNEL__ */ 621 622#define SI_LOAD_SHIFT 16 623struct sysinfo { 624 long uptime; /* Seconds since boot */ 625 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */ 626 unsigned long totalram; /* Total usable main memory size */ 627 unsigned long freeram; /* Available memory size */ 628 unsigned long sharedram; /* Amount of shared memory */ 629 unsigned long bufferram; /* Memory used by buffers */ 630 unsigned long totalswap; /* Total swap space size */ 631 unsigned long freeswap; /* swap space still available */ 632 unsigned short procs; /* Number of current processes */ 633 unsigned short pad; /* explicit padding for m68k */ 634 unsigned long totalhigh; /* Total high memory size */ 635 unsigned long freehigh; /* Available high memory size */ 636 unsigned int mem_unit; /* Memory unit size in bytes */ 637 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */ 638}; 639 640/* Force a compilation error if a constant expression is not a power of 2 */ 641#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ 642 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) 643 644/* Force a compilation error if condition is true, but also produce a 645 result (of value 0 and type size_t), so the expression can be used 646 e.g. in a structure initializer (or where-ever else comma expressions 647 aren't permitted). */ 648#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) 649#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) 650 651/** 652 * BUILD_BUG_ON - break compile if a condition is true. 653 * @condition: the condition which the compiler should know is false. 654 * 655 * If you have some code which relies on certain constants being equal, or 656 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to 657 * detect if someone changes it. 658 * 659 * The implementation uses gcc's reluctance to create a negative array, but 660 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments 661 * to inline functions). So as a fallback we use the optimizer; if it can't 662 * prove the condition is false, it will cause a link error on the undefined 663 * "__build_bug_on_failed". This error message can be harder to track down 664 * though, hence the two different methods. 665 */ 666#ifndef __OPTIMIZE__ 667#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 668#else 669extern int __build_bug_on_failed; 670#define BUILD_BUG_ON(condition) \ 671 do { \ 672 ((void)sizeof(char[1 - 2*!!(condition)])); \ 673 if (condition) __build_bug_on_failed = 1; \ 674 } while(0) 675#endif 676 677/* Trap pasters of __FUNCTION__ at compile-time */ 678#define __FUNCTION__ (__func__) 679 680/* This helps us to avoid #ifdef CONFIG_NUMA */ 681#ifdef CONFIG_NUMA 682#define NUMA_BUILD 1 683#else 684#define NUMA_BUILD 0 685#endif 686 687/* This helps us avoid #ifdef CONFIG_COMPACTION */ 688#ifdef CONFIG_COMPACTION 689#define COMPACTION_BUILD 1 690#else 691#define COMPACTION_BUILD 0 692#endif 693 694/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 695#ifdef CONFIG_FTRACE_MCOUNT_RECORD 696# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 697#endif 698 699#endif