1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2016 Mellanox Technologies, Ltd. 6 * Copyright (c) 2014-2015 François Tigeot 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice unmodified, this list of conditions, and the following 14 * disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 #ifndef _LINUX_KERNEL_H_ 33 #define _LINUX_KERNEL_H_ 34 35 #include <sys/cdefs.h> 36 #include <sys/types.h> 37 #include <sys/systm.h> 38 #include <sys/param.h> 39 #include <sys/libkern.h> 40 #include <sys/stat.h> 41 #include <sys/smp.h> 42 #include <sys/stddef.h> 43 #include <sys/syslog.h> 44 #include <sys/time.h> 45 46 #include <linux/bitops.h> 47 #include <linux/compiler.h> 48 #include <linux/stringify.h> 49 #include <linux/errno.h> 50 #include <linux/sched.h> 51 #include <linux/types.h> 52 #include <linux/jiffies.h> 53 #include <linux/log2.h> 54 55 #include <asm/byteorder.h> 56 #include <asm/uaccess.h> 57 58 #include <machine/stdarg.h> 59 60 #define KERN_CONT "" 61 #define KERN_EMERG "<0>" 62 #define KERN_ALERT "<1>" 63 #define KERN_CRIT "<2>" 64 #define KERN_ERR "<3>" 65 #define KERN_WARNING "<4>" 66 #define KERN_NOTICE "<5>" 67 #define KERN_INFO "<6>" 68 #define KERN_DEBUG "<7>" 69 70 #define U8_MAX ((u8)~0U) 71 #define S8_MAX ((s8)(U8_MAX >> 1)) 72 #define S8_MIN ((s8)(-S8_MAX - 1)) 73 #define U16_MAX ((u16)~0U) 74 #define S16_MAX ((s16)(U16_MAX >> 1)) 75 #define S16_MIN ((s16)(-S16_MAX - 1)) 76 #define U32_MAX ((u32)~0U) 77 #define S32_MAX ((s32)(U32_MAX >> 1)) 78 #define S32_MIN ((s32)(-S32_MAX - 1)) 79 #define U64_MAX ((u64)~0ULL) 80 #define S64_MAX ((s64)(U64_MAX >> 1)) 81 #define S64_MIN ((s64)(-S64_MAX - 1)) 82 83 #define S8_C(x) x 84 #define U8_C(x) x ## U 85 #define S16_C(x) x 86 #define U16_C(x) x ## U 87 #define S32_C(x) x 88 #define U32_C(x) x ## U 89 #define S64_C(x) x ## LL 90 #define U64_C(x) x ## ULL 91 92 /* 93 * BUILD_BUG_ON() can happen inside functions where _Static_assert() does not 94 * seem to work. Use old-schoold-ish CTASSERT from before commit 95 * a3085588a88fa58eb5b1eaae471999e1995a29cf but also make sure we do not 96 * end up with an unused typedef or variable. The compiler should optimise 97 * it away entirely. 98 */ 99 #define _O_CTASSERT(x) _O__CTASSERT(x, __LINE__) 100 #define _O__CTASSERT(x, y) _O___CTASSERT(x, y) 101 #define _O___CTASSERT(x, y) while (0) { \ 102 typedef char __assert_line_ ## y[(x) ? 1 : -1]; \ 103 __assert_line_ ## y _x; \ 104 _x[0] = '\0'; \ 105 } 106 107 #define BUILD_BUG() do { CTASSERT(0); } while (0) 108 #define BUILD_BUG_ON(x) _O_CTASSERT(!(x)) 109 #define BUILD_BUG_ON_MSG(x, msg) BUILD_BUG_ON(x) 110 #define BUILD_BUG_ON_NOT_POWER_OF_2(x) BUILD_BUG_ON(!powerof2(x)) 111 #define BUILD_BUG_ON_INVALID(expr) while (0) { (void)(expr); } 112 113 extern const volatile int lkpi_build_bug_on_zero; 114 #define BUILD_BUG_ON_ZERO(x) ((x) ? lkpi_build_bug_on_zero : 0) 115 116 #define BUG() panic("BUG at %s:%d", __FILE__, __LINE__) 117 #define BUG_ON(cond) do { \ 118 if (cond) { \ 119 panic("BUG ON %s failed at %s:%d", \ 120 __stringify(cond), __FILE__, __LINE__); \ 121 } \ 122 } while (0) 123 124 #define WARN_ON(cond) ({ \ 125 bool __ret = (cond); \ 126 if (__ret) { \ 127 printf("WARNING %s failed at %s:%d\n", \ 128 __stringify(cond), __FILE__, __LINE__); \ 129 linux_dump_stack(); \ 130 } \ 131 unlikely(__ret); \ 132 }) 133 134 #define WARN_ON_SMP(cond) WARN_ON(cond) 135 136 #define WARN_ON_ONCE(cond) ({ \ 137 static bool __warn_on_once; \ 138 bool __ret = (cond); \ 139 if (__ret && !__warn_on_once) { \ 140 __warn_on_once = 1; \ 141 printf("WARNING %s failed at %s:%d\n", \ 142 __stringify(cond), __FILE__, __LINE__); \ 143 linux_dump_stack(); \ 144 } \ 145 unlikely(__ret); \ 146 }) 147 148 #define oops_in_progress SCHEDULER_STOPPED() 149 150 #undef ALIGN 151 #define ALIGN(x, y) roundup2((x), (y)) 152 #undef PTR_ALIGN 153 #define PTR_ALIGN(p, a) ((__typeof(p))ALIGN((uintptr_t)(p), (a))) 154 #define IS_ALIGNED(x, a) (((x) & ((__typeof(x))(a) - 1)) == 0) 155 #define DIV_ROUND_UP(x, n) howmany(x, n) 156 #define __KERNEL_DIV_ROUND_UP(x, n) howmany(x, n) 157 #define DIV_ROUND_UP_ULL(x, n) DIV_ROUND_UP((unsigned long long)(x), (n)) 158 #define DIV_ROUND_DOWN_ULL(x, n) (((unsigned long long)(x) / (n)) * (n)) 159 #define FIELD_SIZEOF(t, f) sizeof(((t *)0)->f) 160 161 #define printk(...) printf(__VA_ARGS__) 162 #define vprintk(f, a) vprintf(f, a) 163 164 #define asm __asm 165 166 extern void linux_dump_stack(void); 167 #define dump_stack() linux_dump_stack() 168 169 struct va_format { 170 const char *fmt; 171 va_list *va; 172 }; 173 174 static inline int 175 vscnprintf(char *buf, size_t size, const char *fmt, va_list args) 176 { 177 ssize_t ssize = size; 178 int i; 179 180 i = vsnprintf(buf, size, fmt, args); 181 182 return ((i >= ssize) ? (ssize - 1) : i); 183 } 184 185 static inline int 186 scnprintf(char *buf, size_t size, const char *fmt, ...) 187 { 188 va_list args; 189 int i; 190 191 va_start(args, fmt); 192 i = vscnprintf(buf, size, fmt, args); 193 va_end(args); 194 195 return (i); 196 } 197 198 /* 199 * The "pr_debug()" and "pr_devel()" macros should produce zero code 200 * unless DEBUG is defined: 201 */ 202 #ifdef DEBUG 203 extern int linuxkpi_debug; 204 #define pr_debug(fmt, ...) \ 205 do { \ 206 if (linuxkpi_debug) \ 207 log(LOG_DEBUG, fmt, ##__VA_ARGS__); \ 208 } while (0) 209 #define pr_devel(fmt, ...) \ 210 log(LOG_DEBUG, pr_fmt(fmt), ##__VA_ARGS__) 211 #else 212 #define pr_debug(fmt, ...) \ 213 ({ if (0) log(LOG_DEBUG, fmt, ##__VA_ARGS__); 0; }) 214 #define pr_devel(fmt, ...) \ 215 ({ if (0) log(LOG_DEBUG, pr_fmt(fmt), ##__VA_ARGS__); 0; }) 216 #endif 217 218 #ifndef pr_fmt 219 #define pr_fmt(fmt) fmt 220 #endif 221 222 /* 223 * Print a one-time message (analogous to WARN_ONCE() et al): 224 */ 225 #define printk_once(...) do { \ 226 static bool __print_once; \ 227 \ 228 if (!__print_once) { \ 229 __print_once = true; \ 230 printk(__VA_ARGS__); \ 231 } \ 232 } while (0) 233 234 /* 235 * Log a one-time message (analogous to WARN_ONCE() et al): 236 */ 237 #define log_once(level,...) do { \ 238 static bool __log_once; \ 239 \ 240 if (unlikely(!__log_once)) { \ 241 __log_once = true; \ 242 log(level, __VA_ARGS__); \ 243 } \ 244 } while (0) 245 246 #define pr_emerg(fmt, ...) \ 247 log(LOG_EMERG, pr_fmt(fmt), ##__VA_ARGS__) 248 #define pr_alert(fmt, ...) \ 249 log(LOG_ALERT, pr_fmt(fmt), ##__VA_ARGS__) 250 #define pr_crit(fmt, ...) \ 251 log(LOG_CRIT, pr_fmt(fmt), ##__VA_ARGS__) 252 #define pr_err(fmt, ...) \ 253 log(LOG_ERR, pr_fmt(fmt), ##__VA_ARGS__) 254 #define pr_err_once(fmt, ...) \ 255 log_once(LOG_ERR, pr_fmt(fmt), ##__VA_ARGS__) 256 #define pr_warning(fmt, ...) \ 257 log(LOG_WARNING, pr_fmt(fmt), ##__VA_ARGS__) 258 #define pr_warn(...) \ 259 pr_warning(__VA_ARGS__) 260 #define pr_warn_once(fmt, ...) \ 261 log_once(LOG_WARNING, pr_fmt(fmt), ##__VA_ARGS__) 262 #define pr_notice(fmt, ...) \ 263 log(LOG_NOTICE, pr_fmt(fmt), ##__VA_ARGS__) 264 #define pr_info(fmt, ...) \ 265 log(LOG_INFO, pr_fmt(fmt), ##__VA_ARGS__) 266 #define pr_info_once(fmt, ...) \ 267 log_once(LOG_INFO, pr_fmt(fmt), ##__VA_ARGS__) 268 #define pr_cont(fmt, ...) \ 269 printk(KERN_CONT fmt, ##__VA_ARGS__) 270 #define pr_warn_ratelimited(...) do { \ 271 static linux_ratelimit_t __ratelimited; \ 272 if (linux_ratelimited(&__ratelimited)) \ 273 pr_warning(__VA_ARGS__); \ 274 } while (0) 275 276 #ifndef WARN 277 #define WARN(condition, ...) ({ \ 278 bool __ret_warn_on = (condition); \ 279 if (unlikely(__ret_warn_on)) \ 280 pr_warning(__VA_ARGS__); \ 281 unlikely(__ret_warn_on); \ 282 }) 283 #endif 284 285 #ifndef WARN_ONCE 286 #define WARN_ONCE(condition, ...) ({ \ 287 bool __ret_warn_on = (condition); \ 288 if (unlikely(__ret_warn_on)) \ 289 pr_warn_once(__VA_ARGS__); \ 290 unlikely(__ret_warn_on); \ 291 }) 292 #endif 293 294 #define container_of(ptr, type, member) \ 295 ({ \ 296 const __typeof(((type *)0)->member) *__p = (ptr); \ 297 (type *)((uintptr_t)__p - offsetof(type, member)); \ 298 }) 299 300 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) 301 302 #define u64_to_user_ptr(val) ((void *)(uintptr_t)(val)) 303 304 static inline unsigned long long 305 simple_strtoull(const char *cp, char **endp, unsigned int base) 306 { 307 return (strtouq(cp, endp, base)); 308 } 309 310 static inline long long 311 simple_strtoll(const char *cp, char **endp, unsigned int base) 312 { 313 return (strtoq(cp, endp, base)); 314 } 315 316 static inline unsigned long 317 simple_strtoul(const char *cp, char **endp, unsigned int base) 318 { 319 return (strtoul(cp, endp, base)); 320 } 321 322 static inline long 323 simple_strtol(const char *cp, char **endp, unsigned int base) 324 { 325 return (strtol(cp, endp, base)); 326 } 327 328 static inline int 329 kstrtoul(const char *cp, unsigned int base, unsigned long *res) 330 { 331 char *end; 332 333 *res = strtoul(cp, &end, base); 334 335 /* skip newline character, if any */ 336 if (*end == '\n') 337 end++; 338 if (*cp == 0 || *end != 0) 339 return (-EINVAL); 340 return (0); 341 } 342 343 static inline int 344 kstrtol(const char *cp, unsigned int base, long *res) 345 { 346 char *end; 347 348 *res = strtol(cp, &end, base); 349 350 /* skip newline character, if any */ 351 if (*end == '\n') 352 end++; 353 if (*cp == 0 || *end != 0) 354 return (-EINVAL); 355 return (0); 356 } 357 358 static inline int 359 kstrtoint(const char *cp, unsigned int base, int *res) 360 { 361 char *end; 362 long temp; 363 364 *res = temp = strtol(cp, &end, base); 365 366 /* skip newline character, if any */ 367 if (*end == '\n') 368 end++; 369 if (*cp == 0 || *end != 0) 370 return (-EINVAL); 371 if (temp != (int)temp) 372 return (-ERANGE); 373 return (0); 374 } 375 376 static inline int 377 kstrtouint(const char *cp, unsigned int base, unsigned int *res) 378 { 379 char *end; 380 unsigned long temp; 381 382 *res = temp = strtoul(cp, &end, base); 383 384 /* skip newline character, if any */ 385 if (*end == '\n') 386 end++; 387 if (*cp == 0 || *end != 0) 388 return (-EINVAL); 389 if (temp != (unsigned int)temp) 390 return (-ERANGE); 391 return (0); 392 } 393 394 static inline int 395 kstrtou16(const char *cp, unsigned int base, u16 *res) 396 { 397 char *end; 398 unsigned long temp; 399 400 *res = temp = strtoul(cp, &end, base); 401 402 /* skip newline character, if any */ 403 if (*end == '\n') 404 end++; 405 if (*cp == 0 || *end != 0) 406 return (-EINVAL); 407 if (temp != (u16)temp) 408 return (-ERANGE); 409 return (0); 410 } 411 412 static inline int 413 kstrtou32(const char *cp, unsigned int base, u32 *res) 414 { 415 char *end; 416 unsigned long temp; 417 418 *res = temp = strtoul(cp, &end, base); 419 420 /* skip newline character, if any */ 421 if (*end == '\n') 422 end++; 423 if (*cp == 0 || *end != 0) 424 return (-EINVAL); 425 if (temp != (u32)temp) 426 return (-ERANGE); 427 return (0); 428 } 429 430 static inline int 431 kstrtou64(const char *cp, unsigned int base, u64 *res) 432 { 433 char *end; 434 435 *res = strtouq(cp, &end, base); 436 437 /* skip newline character, if any */ 438 if (*end == '\n') 439 end++; 440 if (*cp == 0 || *end != 0) 441 return (-EINVAL); 442 return (0); 443 } 444 445 static inline int 446 kstrtobool(const char *s, bool *res) 447 { 448 int len; 449 450 if (s == NULL || (len = strlen(s)) == 0 || res == NULL) 451 return (-EINVAL); 452 453 /* skip newline character, if any */ 454 if (s[len - 1] == '\n') 455 len--; 456 457 if (len == 1 && strchr("yY1", s[0]) != NULL) 458 *res = true; 459 else if (len == 1 && strchr("nN0", s[0]) != NULL) 460 *res = false; 461 else if (strncasecmp("on", s, len) == 0) 462 *res = true; 463 else if (strncasecmp("off", s, len) == 0) 464 *res = false; 465 else 466 return (-EINVAL); 467 468 return (0); 469 } 470 471 static inline int 472 kstrtobool_from_user(const char __user *s, size_t count, bool *res) 473 { 474 char buf[8] = {}; 475 476 if (count > (sizeof(buf) - 1)) 477 count = (sizeof(buf) - 1); 478 479 if (copy_from_user(buf, s, count)) 480 return (-EFAULT); 481 482 return (kstrtobool(buf, res)); 483 } 484 485 #define min(x, y) ((x) < (y) ? (x) : (y)) 486 #define max(x, y) ((x) > (y) ? (x) : (y)) 487 488 #define min3(a, b, c) min(a, min(b,c)) 489 #define max3(a, b, c) max(a, max(b,c)) 490 491 #define min_t(type, x, y) ({ \ 492 type __min1 = (x); \ 493 type __min2 = (y); \ 494 __min1 < __min2 ? __min1 : __min2; }) 495 496 #define max_t(type, x, y) ({ \ 497 type __max1 = (x); \ 498 type __max2 = (y); \ 499 __max1 > __max2 ? __max1 : __max2; }) 500 501 #define offsetofend(t, m) \ 502 (offsetof(t, m) + sizeof((((t *)0)->m))) 503 504 #define clamp_t(type, _x, min, max) min_t(type, max_t(type, _x, min), max) 505 #define clamp(x, lo, hi) min( max(x,lo), hi) 506 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) 507 508 /* 509 * This looks more complex than it should be. But we need to 510 * get the type for the ~ right in round_down (it needs to be 511 * as wide as the result!), and we want to evaluate the macro 512 * arguments just once each. 513 */ 514 #define __round_mask(x, y) ((__typeof__(x))((y)-1)) 515 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 516 #define round_down(x, y) ((x) & ~__round_mask(x, y)) 517 518 #define smp_processor_id() PCPU_GET(cpuid) 519 #define num_possible_cpus() mp_ncpus 520 #define num_online_cpus() mp_ncpus 521 522 #if defined(__i386__) || defined(__amd64__) 523 extern bool linux_cpu_has_clflush; 524 #define cpu_has_clflush linux_cpu_has_clflush 525 #endif 526 527 typedef struct pm_message { 528 int event; 529 } pm_message_t; 530 531 /* Swap values of a and b */ 532 #define swap(a, b) do { \ 533 typeof(a) _swap_tmp = a; \ 534 a = b; \ 535 b = _swap_tmp; \ 536 } while (0) 537 538 #define DIV_ROUND_CLOSEST(x, divisor) (((x) + ((divisor) / 2)) / (divisor)) 539 540 #define DIV_ROUND_CLOSEST_ULL(x, divisor) ({ \ 541 __typeof(divisor) __d = (divisor); \ 542 unsigned long long __ret = (x) + (__d) / 2; \ 543 __ret /= __d; \ 544 __ret; \ 545 }) 546 547 static inline uintmax_t 548 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor) 549 { 550 uintmax_t q = (x / divisor); 551 uintmax_t r = (x % divisor); 552 553 return ((q * multiplier) + ((r * multiplier) / divisor)); 554 } 555 556 static inline int64_t 557 abs64(int64_t x) 558 { 559 return (x < 0 ? -x : x); 560 } 561 562 typedef struct linux_ratelimit { 563 struct timeval lasttime; 564 int counter; 565 } linux_ratelimit_t; 566 567 static inline bool 568 linux_ratelimited(linux_ratelimit_t *rl) 569 { 570 return (ppsratecheck(&rl->lasttime, &rl->counter, 1)); 571 } 572 573 #define struct_size(ptr, field, num) ({ \ 574 const size_t __size = offsetof(__typeof(*(ptr)), field); \ 575 const size_t __max = (SIZE_MAX - __size) / sizeof((ptr)->field[0]); \ 576 ((num) > __max) ? SIZE_MAX : (__size + sizeof((ptr)->field[0]) * (num)); \ 577 }) 578 579 #define __is_constexpr(x) \ 580 __builtin_constant_p(x) 581 582 /* 583 * The is_signed() macro below returns true if the passed data type is 584 * signed. Else false is returned. 585 */ 586 #define is_signed(datatype) (((datatype)-1 / (datatype)2) == (datatype)0) 587 588 /* 589 * The type_max() macro below returns the maxium positive value the 590 * passed data type can hold. 591 */ 592 #define type_max(datatype) ( \ 593 (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MAX : UINT64_MAX) : \ 594 (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MAX : UINT32_MAX) : \ 595 (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MAX : UINT16_MAX) : \ 596 (is_signed(datatype) ? INT8_MAX : UINT8_MAX) \ 597 ) 598 599 /* 600 * The type_min() macro below returns the minimum value the passed 601 * data type can hold. For unsigned types the minimum value is always 602 * zero. For signed types it may vary. 603 */ 604 #define type_min(datatype) ( \ 605 (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MIN : 0) : \ 606 (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MIN : 0) : \ 607 (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MIN : 0) : \ 608 (is_signed(datatype) ? INT8_MIN : 0) \ 609 ) 610 611 #define TAINT_WARN 0 612 #define test_taint(x) (0) 613 614 /* 615 * Checking if an option is defined would be easy if we could do CPP inside CPP. 616 * The defined case whether -Dxxx or -Dxxx=1 are easy to deal with. In either 617 * case the defined value is "1". A more general -Dxxx=<c> case will require 618 * more effort to deal with all possible "true" values. Hope we do not have 619 * to do this as well. 620 * The real problem is the undefined case. To avoid this problem we do the 621 * concat/varargs trick: "yyy" ## xxx can make two arguments if xxx is "1" 622 * by having a #define for yyy_1 which is "ignore,". 623 * Otherwise we will just get "yyy". 624 * Need to be careful about variable substitutions in macros though. 625 * This way we make a (true, false) problem a (don't care, true, false) or a 626 * (don't care true, false). Then we can use a variadic macro to only select 627 * the always well known and defined argument #2. And that seems to be 628 * exactly what we need. Use 1 for true and 0 for false to also allow 629 * #if IS_*() checks pre-compiler checks which do not like #if true. 630 */ 631 #define ___XAB_1 dontcare, 632 #define ___IS_XAB(_ignore, _x, ...) (_x) 633 #define __IS_XAB(_x) ___IS_XAB(_x 1, 0) 634 #define _IS_XAB(_x) __IS_XAB(__CONCAT(___XAB_, _x)) 635 636 /* This is if CONFIG_ccc=y. */ 637 #define IS_BUILTIN(_x) _IS_XAB(_x) 638 /* This is if CONFIG_ccc=m. */ 639 #define IS_MODULE(_x) _IS_XAB(_x ## _MODULE) 640 /* This is if CONFIG_ccc is compiled in(=y) or a module(=m). */ 641 #define IS_ENABLED(_x) (IS_BUILTIN(_x) || IS_MODULE(_x)) 642 /* 643 * This is weird case. If the CONFIG_ccc is builtin (=y) this returns true; 644 * or if the CONFIG_ccc is a module (=m) and the caller is built as a module 645 * (-DMODULE defined) this returns true, but if the callers is not a module 646 * (-DMODULE not defined, which means caller is BUILTIN) then it returns 647 * false. In other words, a module can reach the kernel, a module can reach 648 * a module, but the kernel cannot reach a module, and code never compiled 649 * cannot be reached either. 650 * XXX -- I'd hope the module-to-module case would be handled by a proper 651 * module dependency definition (MODULE_DEPEND() in FreeBSD). 652 */ 653 #define IS_REACHABLE(_x) (IS_BUILTIN(_x) || \ 654 (IS_MODULE(_x) && IS_BUILTIN(MODULE))) 655 656 #endif /* _LINUX_KERNEL_H_ */ 657