kernel.h revision 1.3
1 /* $NetBSD: kernel.h,v 1.3 2014/07/16 20:56:24 riastradh 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 #include <sys/systm.h> 39 40 #define oops_in_progress (panicstr != NULL) 41 42 #define IS_ENABLED(option) 0 /* XXX Hmm... */ 43 44 #define __printf __printflike 45 #define __user 46 #define __must_check /* __attribute__((warn_unused_result)), if GCC */ 47 #define __always_unused __unused 48 49 #define barrier() __insn_barrier() 50 #define likely(X) __predict_true(X) 51 #define unlikely(X) __predict_false(X) 52 53 /* 54 * XXX Linux kludge to work around GCC uninitialized variable warning. 55 * Linux does `x = x', which is bollocks. 56 */ 57 #define uninitialized_var(x) x = 0 58 59 /* XXX These will multiply evaluate their arguments. */ 60 #define max_t(T, X, Y) MAX(X, Y) 61 #define min_t(T, X, Y) MIN(X, Y) 62 63 #define clamp_t(T, X, MIN, MAX) min_t(T, max_t(T, X, MIN), MAX) 64 65 /* 66 * Rounding to nearest. 67 */ 68 #define DIV_ROUND_CLOSEST(N, D) \ 69 ((0 < (N)) ? (((N) + ((D) / 2)) / (D)) \ 70 : (((N) - ((D) / 2)) / (D))) 71 72 /* 73 * Rounding to what may or may not be powers of two. 74 */ 75 #define DIV_ROUND_UP(X, N) (((X) + (N) - 1) / (N)) 76 #define DIV_ROUND_UP_ULL(X, N) DIV_ROUND_UP((unsigned long long)(X), (N)) 77 78 /* 79 * Rounding to powers of two -- carefully avoiding multiple evaluation 80 * of arguments and pitfalls with C integer arithmetic rules. 81 */ 82 #define round_up(X, N) ((((X) - 1) | ((N) - 1)) + 1) 83 #define round_down(X, N) ((X) & ~(uintmax_t)((N) - 1)) 84 85 /* 86 * These select 32-bit halves of what may be 32- or 64-bit quantities, 87 * for which straight 32-bit shifts may be undefined behaviour (and do 88 * the wrong thing on most machines: return the input unshifted by 89 * ignoring the upper bits of the shift count). 90 */ 91 #define upper_32_bits(X) ((uint32_t) (((X) >> 16) >> 16)) 92 #define lower_32_bits(X) ((uint32_t) ((X) & 0xffffffffUL)) 93 94 /* 95 * Given x = &c->f, container_of(x, T, f) gives us back c, where T is 96 * the type of c. 97 */ 98 #define container_of(PTR, TYPE, FIELD) \ 99 ((TYPE *)(((char *)(PTR)) - offsetof(TYPE, FIELD) + \ 100 0*sizeof((PTR) - \ 101 &((TYPE *)(((char *)(PTR)) - \ 102 offsetof(TYPE, FIELD)))->FIELD))) 103 104 #define ARRAY_SIZE(ARRAY) __arraycount(ARRAY) 105 106 #define swap(X, Y) do \ 107 { \ 108 /* XXX Kludge for type-safety. */ \ 109 if (&(X) != &(Y)) { \ 110 CTASSERT(sizeof(X) == sizeof(Y)); \ 111 /* XXX Can't do this much better without typeof. */ \ 112 char __swap_tmp[sizeof(X)]; \ 113 (void)memcpy(__swap_tmp, &(X), sizeof(X)); \ 114 (void)memcpy(&(X), &(Y), sizeof(X)); \ 115 (void)memcpy(&(Y), __swap_tmp, sizeof(X)); \ 116 } \ 117 } while (0) 118 119 static inline int64_t 120 abs64(int64_t x) 121 { 122 return (x < 0? (-x) : x); 123 } 124 125 static inline uintmax_t 126 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor) 127 { 128 uintmax_t q = (x / divisor); 129 uintmax_t r = (x % divisor); 130 131 return ((q * multiplier) + ((r * multiplier) / divisor)); 132 } 133 134 static int panic_timeout __unused = 0; 135 136 static inline int 137 vscnprintf(char *buf, size_t size, const char *fmt, va_list va) 138 { 139 int ret; 140 141 ret = vsnprintf(buf, size, fmt, va); 142 if (__predict_false(ret < 0)) 143 return ret; 144 if (__predict_false(size == 0)) 145 return 0; 146 if (__predict_false(size <= ret)) 147 return (size - 1); 148 149 return ret; 150 } 151 152 static inline int 153 scnprintf(char *buf, size_t size, const char *fmt, ...) 154 { 155 va_list va; 156 int ret; 157 158 va_start(va, fmt); 159 ret = vscnprintf(buf, size, fmt, va); 160 va_end(va); 161 162 return ret; 163 } 164 165 #endif /* _LINUX_KERNEL_H_ */ 166
Indexes created Tue Sep 23 20:09:58 GMT 2025