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)) 112 113 struct completion; 114 struct pt_regs; 115 struct user; 116 117 #ifdef CONFIG_PREEMPT_VOLUNTARY 118 extern 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_ATOMIC_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 170 void might_fault(void); 171 #else 172 static inline void might_fault(void) 173 { 174 might_sleep(); 175 } 176 #endif 177 178 extern struct atomic_notifier_head panic_notifier_list; 179 extern long (*panic_blink)(int state); 180 NORET_TYPE void panic(const char * fmt, ...) 181 __attribute__ ((NORET_AND format (printf, 1, 2))) __cold; 182 extern void oops_enter(void); 183 extern void oops_exit(void); 184 void print_oops_end_marker(void); 185 extern int oops_may_print(void); 186 NORET_TYPE void do_exit(long error_code) 187 ATTRIB_NORET; 188 NORET_TYPE void complete_and_exit(struct completion *, long) 189 ATTRIB_NORET; 190 191 /* Internal, do not use. */ 192 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 193 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 194 195 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 196 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 197 static 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 } 209 210 static 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 } 222 223 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 224 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 225 226 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 227 { 228 return kstrtoull(s, base, res); 229 } 230 231 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 232 { 233 return kstrtoll(s, base, res); 234 } 235 236 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 237 { 238 return kstrtouint(s, base, res); 239 } 240 241 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 242 { 243 return kstrtoint(s, base, res); 244 } 245 246 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 247 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 248 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 249 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 250 251 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 252 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 253 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 254 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 255 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 256 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 257 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 258 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 259 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 260 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 261 262 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 263 { 264 return kstrtoull_from_user(s, count, base, res); 265 } 266 267 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 268 { 269 return kstrtoll_from_user(s, count, base, res); 270 } 271 272 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 273 { 274 return kstrtouint_from_user(s, count, base, res); 275 } 276 277 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 278 { 279 return kstrtoint_from_user(s, count, base, res); 280 } 281 282 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 283 extern long simple_strtol(const char *,char **,unsigned int); 284 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 285 extern long long simple_strtoll(const char *,char **,unsigned int); 286 #define strict_strtoul kstrtoul 287 #define strict_strtol kstrtol 288 #define strict_strtoull kstrtoull 289 #define strict_strtoll kstrtoll 290 291 extern int sprintf(char * buf, const char * fmt, ...) 292 __attribute__ ((format (printf, 2, 3))); 293 extern int vsprintf(char *buf, const char *, va_list) 294 __attribute__ ((format (printf, 2, 0))); 295 extern int snprintf(char * buf, size_t size, const char * fmt, ...) 296 __attribute__ ((format (printf, 3, 4))); 297 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) 298 __attribute__ ((format (printf, 3, 0))); 299 extern int scnprintf(char * buf, size_t size, const char * fmt, ...) 300 __attribute__ ((format (printf, 3, 4))); 301 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 302 __attribute__ ((format (printf, 3, 0))); 303 extern char *kasprintf(gfp_t gfp, const char *fmt, ...) 304 __attribute__ ((format (printf, 2, 3))); 305 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 306 307 extern int sscanf(const char *, const char *, ...) 308 __attribute__ ((format (scanf, 2, 3))); 309 extern int vsscanf(const char *, const char *, va_list) 310 __attribute__ ((format (scanf, 2, 0))); 311 312 extern int get_option(char **str, int *pint); 313 extern char *get_options(const char *str, int nints, int *ints); 314 extern unsigned long long memparse(const char *ptr, char **retptr); 315 316 extern int core_kernel_text(unsigned long addr); 317 extern int core_kernel_data(unsigned long addr); 318 extern int __kernel_text_address(unsigned long addr); 319 extern int kernel_text_address(unsigned long addr); 320 extern int func_ptr_is_kernel_text(void *ptr); 321 322 struct pid; 323 extern struct pid *session_of_pgrp(struct pid *pgrp); 324 325 unsigned long int_sqrt(unsigned long); 326 327 extern void bust_spinlocks(int yes); 328 extern void wake_up_klogd(void); 329 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 330 extern int panic_timeout; 331 extern int panic_on_oops; 332 extern int panic_on_unrecovered_nmi; 333 extern int panic_on_io_nmi; 334 extern const char *print_tainted(void); 335 extern void add_taint(unsigned flag); 336 extern int test_taint(unsigned flag); 337 extern unsigned long get_taint(void); 338 extern int root_mountflags; 339 340 extern bool early_boot_irqs_disabled; 341 342 /* Values used for system_state */ 343 extern enum system_states { 344 SYSTEM_BOOTING, 345 SYSTEM_RUNNING, 346 SYSTEM_HALT, 347 SYSTEM_POWER_OFF, 348 SYSTEM_RESTART, 349 SYSTEM_SUSPEND_DISK, 350 } system_state; 351 352 #define TAINT_PROPRIETARY_MODULE 0 353 #define TAINT_FORCED_MODULE 1 354 #define TAINT_UNSAFE_SMP 2 355 #define TAINT_FORCED_RMMOD 3 356 #define TAINT_MACHINE_CHECK 4 357 #define TAINT_BAD_PAGE 5 358 #define TAINT_USER 6 359 #define TAINT_DIE 7 360 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 361 #define TAINT_WARN 9 362 #define TAINT_CRAP 10 363 #define TAINT_FIRMWARE_WORKAROUND 11 364 365 extern const char hex_asc[]; 366 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 367 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 368 369 static inline char *pack_hex_byte(char *buf, u8 byte) 370 { 371 *buf++ = hex_asc_hi(byte); 372 *buf++ = hex_asc_lo(byte); 373 return buf; 374 } 375 376 extern int hex_to_bin(char ch); 377 extern void hex2bin(u8 *dst, const char *src, size_t count); 378 379 /* 380 * General tracing related utility functions - trace_printk(), 381 * tracing_on/tracing_off and tracing_start()/tracing_stop 382 * 383 * Use tracing_on/tracing_off when you want to quickly turn on or off 384 * tracing. It simply enables or disables the recording of the trace events. 385 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 386 * file, which gives a means for the kernel and userspace to interact. 387 * Place a tracing_off() in the kernel where you want tracing to end. 388 * From user space, examine the trace, and then echo 1 > tracing_on 389 * to continue tracing. 390 * 391 * tracing_stop/tracing_start has slightly more overhead. It is used 392 * by things like suspend to ram where disabling the recording of the 393 * trace is not enough, but tracing must actually stop because things 394 * like calling smp_processor_id() may crash the system. 395 * 396 * Most likely, you want to use tracing_on/tracing_off. 397 */ 398 #ifdef CONFIG_RING_BUFFER 399 void tracing_on(void); 400 void tracing_off(void); 401 /* trace_off_permanent stops recording with no way to bring it back */ 402 void tracing_off_permanent(void); 403 int tracing_is_on(void); 404 #else 405 static inline void tracing_on(void) { } 406 static inline void tracing_off(void) { } 407 static inline void tracing_off_permanent(void) { } 408 static inline int tracing_is_on(void) { return 0; } 409 #endif 410 411 enum ftrace_dump_mode { 412 DUMP_NONE, 413 DUMP_ALL, 414 DUMP_ORIG, 415 }; 416 417 #ifdef CONFIG_TRACING 418 extern void tracing_start(void); 419 extern void tracing_stop(void); 420 extern void ftrace_off_permanent(void); 421 422 static inline void __attribute__ ((format (printf, 1, 2))) 423 ____trace_printk_check_format(const char *fmt, ...) 424 { 425 } 426 #define __trace_printk_check_format(fmt, args...) \ 427 do { \ 428 if (0) \ 429 ____trace_printk_check_format(fmt, ##args); \ 430 } while (0) 431 432 /** 433 * trace_printk - printf formatting in the ftrace buffer 434 * @fmt: the printf format for printing 435 * 436 * Note: __trace_printk is an internal function for trace_printk and 437 * the @ip is passed in via the trace_printk macro. 438 * 439 * This function allows a kernel developer to debug fast path sections 440 * that printk is not appropriate for. By scattering in various 441 * printk like tracing in the code, a developer can quickly see 442 * where problems are occurring. 443 * 444 * This is intended as a debugging tool for the developer only. 445 * Please refrain from leaving trace_printks scattered around in 446 * your code. 447 */ 448 449 #define trace_printk(fmt, args...) \ 450 do { \ 451 __trace_printk_check_format(fmt, ##args); \ 452 if (__builtin_constant_p(fmt)) { \ 453 static const char *trace_printk_fmt \ 454 __attribute__((section("__trace_printk_fmt"))) = \ 455 __builtin_constant_p(fmt) ? fmt : NULL; \ 456 \ 457 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 458 } else \ 459 __trace_printk(_THIS_IP_, fmt, ##args); \ 460 } while (0) 461 462 extern int 463 __trace_bprintk(unsigned long ip, const char *fmt, ...) 464 __attribute__ ((format (printf, 2, 3))); 465 466 extern int 467 __trace_printk(unsigned long ip, const char *fmt, ...) 468 __attribute__ ((format (printf, 2, 3))); 469 470 extern void trace_dump_stack(void); 471 472 /* 473 * The double __builtin_constant_p is because gcc will give us an error 474 * if we try to allocate the static variable to fmt if it is not a 475 * constant. Even with the outer if statement. 476 */ 477 #define ftrace_vprintk(fmt, vargs) \ 478 do { \ 479 if (__builtin_constant_p(fmt)) { \ 480 static const char *trace_printk_fmt \ 481 __attribute__((section("__trace_printk_fmt"))) = \ 482 __builtin_constant_p(fmt) ? fmt : NULL; \ 483 \ 484 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 485 } else \ 486 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 487 } while (0) 488 489 extern int 490 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 491 492 extern int 493 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 494 495 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 496 #else 497 static inline int 498 trace_printk(const char *fmt, ...) __attribute__ ((format (printf, 1, 2))); 499 500 static inline void tracing_start(void) { } 501 static inline void tracing_stop(void) { } 502 static inline void ftrace_off_permanent(void) { } 503 static inline void trace_dump_stack(void) { } 504 static inline int 505 trace_printk(const char *fmt, ...) 506 { 507 return 0; 508 } 509 static inline int 510 ftrace_vprintk(const char *fmt, va_list ap) 511 { 512 return 0; 513 } 514 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 515 #endif /* CONFIG_TRACING */ 516 517 /* 518 * min()/max()/clamp() macros that also do 519 * strict type-checking.. See the 520 * "unnecessary" pointer comparison. 521 */ 522 #define min(x, y) ({ \ 523 typeof(x) _min1 = (x); \ 524 typeof(y) _min2 = (y); \ 525 (void) (&_min1 == &_min2); \ 526 _min1 < _min2 ? _min1 : _min2; }) 527 528 #define max(x, y) ({ \ 529 typeof(x) _max1 = (x); \ 530 typeof(y) _max2 = (y); \ 531 (void) (&_max1 == &_max2); \ 532 _max1 > _max2 ? _max1 : _max2; }) 533 534 #define min3(x, y, z) ({ \ 535 typeof(x) _min1 = (x); \ 536 typeof(y) _min2 = (y); \ 537 typeof(z) _min3 = (z); \ 538 (void) (&_min1 == &_min2); \ 539 (void) (&_min1 == &_min3); \ 540 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \ 541 (_min2 < _min3 ? _min2 : _min3); }) 542 543 #define max3(x, y, z) ({ \ 544 typeof(x) _max1 = (x); \ 545 typeof(y) _max2 = (y); \ 546 typeof(z) _max3 = (z); \ 547 (void) (&_max1 == &_max2); \ 548 (void) (&_max1 == &_max3); \ 549 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \ 550 (_max2 > _max3 ? _max2 : _max3); }) 551 552 /** 553 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 554 * @x: value1 555 * @y: value2 556 */ 557 #define min_not_zero(x, y) ({ \ 558 typeof(x) __x = (x); \ 559 typeof(y) __y = (y); \ 560 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 561 562 /** 563 * clamp - return a value clamped to a given range with strict typechecking 564 * @val: current value 565 * @min: minimum allowable value 566 * @max: maximum allowable value 567 * 568 * This macro does strict typechecking of min/max to make sure they are of the 569 * same type as val. See the unnecessary pointer comparisons. 570 */ 571 #define clamp(val, min, max) ({ \ 572 typeof(val) __val = (val); \ 573 typeof(min) __min = (min); \ 574 typeof(max) __max = (max); \ 575 (void) (&__val == &__min); \ 576 (void) (&__val == &__max); \ 577 __val = __val < __min ? __min: __val; \ 578 __val > __max ? __max: __val; }) 579 580 /* 581 * ..and if you can't take the strict 582 * types, you can specify one yourself. 583 * 584 * Or not use min/max/clamp at all, of course. 585 */ 586 #define min_t(type, x, y) ({ \ 587 type __min1 = (x); \ 588 type __min2 = (y); \ 589 __min1 < __min2 ? __min1: __min2; }) 590 591 #define max_t(type, x, y) ({ \ 592 type __max1 = (x); \ 593 type __max2 = (y); \ 594 __max1 > __max2 ? __max1: __max2; }) 595 596 /** 597 * clamp_t - return a value clamped to a given range using a given type 598 * @type: the type of variable to use 599 * @val: current value 600 * @min: minimum allowable value 601 * @max: maximum allowable value 602 * 603 * This macro does no typechecking and uses temporary variables of type 604 * 'type' to make all the comparisons. 605 */ 606 #define clamp_t(type, val, min, max) ({ \ 607 type __val = (val); \ 608 type __min = (min); \ 609 type __max = (max); \ 610 __val = __val < __min ? __min: __val; \ 611 __val > __max ? __max: __val; }) 612 613 /** 614 * clamp_val - return a value clamped to a given range using val's type 615 * @val: current value 616 * @min: minimum allowable value 617 * @max: maximum allowable value 618 * 619 * This macro does no typechecking and uses temporary variables of whatever 620 * type the input argument 'val' is. This is useful when val is an unsigned 621 * type and min and max are literals that will otherwise be assigned a signed 622 * integer type. 623 */ 624 #define clamp_val(val, min, max) ({ \ 625 typeof(val) __val = (val); \ 626 typeof(val) __min = (min); \ 627 typeof(val) __max = (max); \ 628 __val = __val < __min ? __min: __val; \ 629 __val > __max ? __max: __val; }) 630 631 632 /* 633 * swap - swap value of @a and @b 634 */ 635 #define swap(a, b) \ 636 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 637 638 /** 639 * container_of - cast a member of a structure out to the containing structure 640 * @ptr: the pointer to the member. 641 * @type: the type of the container struct this is embedded in. 642 * @member: the name of the member within the struct. 643 * 644 */ 645 #define container_of(ptr, type, member) ({ \ 646 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 647 (type *)( (char *)__mptr - offsetof(type,member) );}) 648 649 #ifdef __CHECKER__ 650 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) 651 #define BUILD_BUG_ON_ZERO(e) (0) 652 #define BUILD_BUG_ON_NULL(e) ((void*)0) 653 #define BUILD_BUG_ON(condition) 654 #else /* __CHECKER__ */ 655 656 /* Force a compilation error if a constant expression is not a power of 2 */ 657 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ 658 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) 659 660 /* Force a compilation error if condition is true, but also produce a 661 result (of value 0 and type size_t), so the expression can be used 662 e.g. in a structure initializer (or where-ever else comma expressions 663 aren't permitted). */ 664 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) 665 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) 666 667 /** 668 * BUILD_BUG_ON - break compile if a condition is true. 669 * @condition: the condition which the compiler should know is false. 670 * 671 * If you have some code which relies on certain constants being equal, or 672 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to 673 * detect if someone changes it. 674 * 675 * The implementation uses gcc's reluctance to create a negative array, but 676 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments 677 * to inline functions). So as a fallback we use the optimizer; if it can't 678 * prove the condition is false, it will cause a link error on the undefined 679 * "__build_bug_on_failed". This error message can be harder to track down 680 * though, hence the two different methods. 681 */ 682 #ifndef __OPTIMIZE__ 683 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 684 #else 685 extern int __build_bug_on_failed; 686 #define BUILD_BUG_ON(condition) \ 687 do { \ 688 ((void)sizeof(char[1 - 2*!!(condition)])); \ 689 if (condition) __build_bug_on_failed = 1; \ 690 } while(0) 691 #endif 692 #endif /* __CHECKER__ */ 693 694 /* Trap pasters of __FUNCTION__ at compile-time */ 695 #define __FUNCTION__ (__func__) 696 697 /* This helps us to avoid #ifdef CONFIG_NUMA */ 698 #ifdef CONFIG_NUMA 699 #define NUMA_BUILD 1 700 #else 701 #define NUMA_BUILD 0 702 #endif 703 704 /* This helps us avoid #ifdef CONFIG_COMPACTION */ 705 #ifdef CONFIG_COMPACTION 706 #define COMPACTION_BUILD 1 707 #else 708 #define COMPACTION_BUILD 0 709 #endif 710 711 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 712 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 713 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 714 #endif 715 716 struct sysinfo; 717 extern int do_sysinfo(struct sysinfo *info); 718 719 #endif /* __KERNEL__ */ 720 721 #define SI_LOAD_SHIFT 16 722 struct sysinfo { 723 long uptime; /* Seconds since boot */ 724 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */ 725 unsigned long totalram; /* Total usable main memory size */ 726 unsigned long freeram; /* Available memory size */ 727 unsigned long sharedram; /* Amount of shared memory */ 728 unsigned long bufferram; /* Memory used by buffers */ 729 unsigned long totalswap; /* Total swap space size */ 730 unsigned long freeswap; /* swap space still available */ 731 unsigned short procs; /* Number of current processes */ 732 unsigned short pad; /* explicit padding for m68k */ 733 unsigned long totalhigh; /* Total high memory size */ 734 unsigned long freehigh; /* Available high memory size */ 735 unsigned int mem_unit; /* Memory unit size in bytes */ 736 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */ 737 }; 738 739 #endif 740