1 /* $NetBSD: kernel.h,v 1.8 2015/08/20 21:41:12 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 #include <sys/systm.h> 39 40 #include <lib/libkern/libkern.h> 41 42 #define oops_in_progress (panicstr != NULL) 43 44 #define IS_ENABLED(option) (option) 45 46 #define __printf __printflike 47 #define __user 48 #define __must_check /* __attribute__((warn_unused_result)), if GCC */ 49 #define __always_unused __unused 50 51 #define barrier() __insn_barrier() 52 #define likely(X) __predict_true(X) 53 #define unlikely(X) __predict_false(X) 54 55 /* 56 * XXX Linux kludge to work around GCC uninitialized variable warning. 57 * Linux does `x = x', which is bollocks. 58 */ 59 #define uninitialized_var(x) x = 0 60 61 /* XXX These will multiply evaluate their arguments. */ 62 #define max_t(T, X, Y) MAX(X, Y) 63 #define min_t(T, X, Y) MIN(X, Y) 64 65 #define clamp_t(T, X, MIN, MAX) min_t(T, max_t(T, X, MIN), MAX) 66 #define clamp(X, MN, MX) MIN(MAX(X, MN), MX) 67 68 /* 69 * Rounding to nearest. 70 */ 71 #define DIV_ROUND_CLOSEST(N, D) \ 72 ((0 < (N)) ? (((N) + ((D) / 2)) / (D)) \ 73 : (((N) - ((D) / 2)) / (D))) 74 75 /* 76 * Rounding to what may or may not be powers of two. 77 */ 78 #define DIV_ROUND_UP(X, N) (((X) + (N) - 1) / (N)) 79 #define DIV_ROUND_UP_ULL(X, N) DIV_ROUND_UP((unsigned long long)(X), (N)) 80 81 /* 82 * Rounding to powers of two -- carefully avoiding multiple evaluation 83 * of arguments and pitfalls with C integer arithmetic rules. 84 */ 85 #define round_up(X, N) ((((X) - 1) | ((N) - 1)) + 1) 86 #define round_down(X, N) ((X) & ~(uintmax_t)((N) - 1)) 87 88 #define IS_ALIGNED(X, N) (((X) & ((N) - 1)) == 0) 89 90 /* 91 * These select 32-bit halves of what may be 32- or 64-bit quantities, 92 * for which straight 32-bit shifts may be undefined behaviour (and do 93 * the wrong thing on most machines: return the input unshifted by 94 * ignoring the upper bits of the shift count). 95 */ 96 #define upper_32_bits(X) ((uint32_t) (((X) >> 16) >> 16)) 97 #define lower_32_bits(X) ((uint32_t) ((X) & 0xffffffffUL)) 98 99 #define ARRAY_SIZE(ARRAY) __arraycount(ARRAY) 100 101 #define swap(X, Y) do \ 102 { \ 103 /* XXX Kludge for type-safety. */ \ 104 if (&(X) != &(Y)) { \ 105 CTASSERT(sizeof(X) == sizeof(Y)); \ 106 /* XXX Can't do this much better without typeof. */ \ 107 char __swap_tmp[sizeof(X)]; \ 108 (void)memcpy(__swap_tmp, &(X), sizeof(X)); \ 109 (void)memcpy(&(X), &(Y), sizeof(X)); \ 110 (void)memcpy(&(Y), __swap_tmp, sizeof(X)); \ 111 } \ 112 } while (0) 113 114 static inline int64_t 115 abs64(int64_t x) 116 { 117 return (x < 0? (-x) : x); 118 } 119 120 static inline uintmax_t 121 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor) 122 { 123 uintmax_t q = (x / divisor); 124 uintmax_t r = (x % divisor); 125 126 return ((q * multiplier) + ((r * multiplier) / divisor)); 127 } 128 129 static int panic_timeout __unused = 0; 130 131 static inline int 132 vscnprintf(char *buf, size_t size, const char *fmt, va_list va) 133 { 134 int ret; 135 136 ret = vsnprintf(buf, size, fmt, va); 137 if (__predict_false(ret < 0)) 138 return ret; 139 if (__predict_false(size == 0)) 140 return 0; 141 if (__predict_false(size <= ret)) 142 return (size - 1); 143 144 return ret; 145 } 146 147 static inline int 148 scnprintf(char *buf, size_t size, const char *fmt, ...) 149 { 150 va_list va; 151 int ret; 152 153 va_start(va, fmt); 154 ret = vscnprintf(buf, size, fmt, va); 155 va_end(va); 156 157 return ret; 158 } 159 160 static inline int 161 kstrtol(const char *s, unsigned base, long *vp) 162 { 163 long long v; 164 165 v = strtoll(s, NULL, base); 166 if (v < LONG_MIN || LONG_MAX < v) 167 return -ERANGE; 168 *vp = v; 169 return 0; 170 } 171 172 #endif /* _LINUX_KERNEL_H_ */ 173