1 /* $NetBSD: kernel.h,v 1.1 2013/09/05 15:28:07 skrll Exp $ */ 2 3 /*- 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 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/param.h> 38 39 #define __printf __printflike 40 #define __user 41 #define __must_check /* __attribute__((warn_unused_result)), if GCC */ 42 #define __always_unused __unused 43 44 #define barrier() __insn_barrier() 45 #define unlikely(X) __predict_false(X) 46 47 #define uninitialized_var(x) x 48 49 /* XXX These will multiply evaluate their arguments. */ 50 #define max_t(T, X, Y) MAX(X, Y) 51 #define min_t(T, X, Y) MIN(X, Y) 52 53 /* 54 * Rounding to what may or may not be powers of two. 55 */ 56 #define DIV_ROUND_UP(X, N) (((X) + (N) - 1) / (N)) 57 58 /* 59 * Rounding to powers of two -- carefully avoiding multiple evaluation 60 * of arguments and pitfalls with C integer arithmetic rules. 61 */ 62 #define round_up(X, N) ((((X) - 1) | ((N) - 1)) + 1) 63 #define round_down(X, N) ((X) & ~(uintmax_t)((N) - 1)) 64 65 /* 66 * These select 32-bit halves of what may be 32- or 64-bit quantities, 67 * for which straight 32-bit shifts may be undefined behaviour (and do 68 * the wrong thing on most machines: return the input unshifted by 69 * ignoring the upper bits of the shift count). 70 */ 71 #define upper_32_bits(X) ((uint32_t) (((X) >> 16) >> 16)) 72 #define lower_32_bits(X) ((uint32_t) ((X) & 0xffffffffUL)) 73 74 /* 75 * Given x = &c->f, container_of(x, T, f) gives us back c, where T is 76 * the type of c. 77 */ 78 #define container_of(PTR, TYPE, FIELD) \ 79 ((void)sizeof((PTR) - \ 80 &((TYPE *)(((char *)(PTR)) - \ 81 offsetof(TYPE, FIELD)))->FIELD), \ 82 ((TYPE *)(((char *)(PTR)) - offsetof(TYPE, FIELD)))) 83 84 #define ARRAY_SIZE(ARRAY) __arraycount(ARRAY) 85 86 #define swap(X, Y) do \ 87 { \ 88 /* XXX Kludge for type-safety. */ \ 89 if (&(X) != &(Y)) { \ 90 CTASSERT(sizeof(X) == sizeof(Y)); \ 91 /* XXX Can't do this much better without typeof. */ \ 92 char __swap_tmp[sizeof(X)]; \ 93 (void)memcpy(__swap_tmp, &(X), sizeof(X)); \ 94 (void)memcpy(&(X), &(Y), sizeof(X)); \ 95 (void)memcpy(&(Y), __swap_tmp, sizeof(X)); \ 96 } \ 97 } while (0) 98 99 static inline int64_t 100 abs64(int64_t x) 101 { 102 return (x < 0? (-x) : x); 103 } 104 105 #endif /* _LINUX_KERNEL_H_ */ 106