1 /* $NetBSD: kernel.h,v 1.21 2018/08/27 14:48:07 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 #include <lib/libkern/libkern.h> 41 #include <linux/bitops.h> 42 #include <linux/printk.h> 43 #include <linux/slab.h> 44 45 #define U16_MAX UINT16_MAX 46 #define U32_MAX UINT32_MAX 47 #define U64_MAX UINT64_MAX 48 49 #define oops_in_progress (panicstr != NULL) 50 51 #define IS_ENABLED(option) (option) 52 #define IS_BUILTIN(option) (1) /* Probably... */ 53 54 #define __printf __printflike 55 #define __user 56 #if __GNUC_PREREQ__(4,0) /* not sure when but this will work */ 57 #define __must_check __attribute__((warn_unused_result)) 58 #else 59 #define __must_check /* nothing */ 60 #endif 61 #define __always_unused __unused 62 #define noinline __noinline 63 64 #define barrier() __insn_barrier() 65 #define likely(X) __predict_true(X) 66 #define unlikely(X) __predict_false(X) 67 68 /* 69 * XXX Linux kludge to work around GCC uninitialized variable warning. 70 * Linux does `x = x', which is bollocks. 71 */ 72 #define uninitialized_var(x) x = 0 73 74 /* XXX These will multiply evaluate their arguments. */ 75 #define min(X, Y) MIN(X, Y) 76 #define max(X, Y) MAX(X, Y) 77 78 #define max_t(T, X, Y) MAX(X, Y) 79 #define min_t(T, X, Y) MIN(X, Y) 80 81 #define clamp_t(T, X, MIN, MAX) min_t(T, max_t(T, X, MIN), MAX) 82 #define clamp(X, MN, MX) MIN(MAX(X, MN), MX) 83 84 #define min3(X, Y, Z) MIN(X, MIN(Y, Z)) 85 #define max3(X, Y, Z) MAX(X, MAX(Y, Z)) 86 87 /* 88 * Rounding to nearest. 89 */ 90 #define DIV_ROUND_CLOSEST(N, D) \ 91 ((0 < (N)) ? (((N) + ((D) / 2)) / (D)) \ 92 : (((N) - ((D) / 2)) / (D))) 93 94 #define DIV_ROUND_CLOSEST_ULL(N, D) (((N) + (D)/2)/(D)) 95 96 /* 97 * Rounding to what may or may not be powers of two. 98 */ 99 #define DIV_ROUND_UP(X, N) (((X) + (N) - 1) / (N)) 100 #define DIV_ROUND_UP_ULL(X, N) DIV_ROUND_UP((unsigned long long)(X), (N)) 101 102 /* 103 * Rounding to powers of two -- carefully avoiding multiple evaluation 104 * of arguments and pitfalls with C integer arithmetic rules. 105 */ 106 #define round_up(X, N) ((((X) - 1) | ((N) - 1)) + 1) 107 #define round_down(X, N) ((X) & ~(uintmax_t)((N) - 1)) 108 109 #define IS_ALIGNED(X, N) (((X) & ((N) - 1)) == 0) 110 111 /* 112 * These select 32-bit halves of what may be 32- or 64-bit quantities, 113 * for which straight 32-bit shifts may be undefined behaviour (and do 114 * the wrong thing on most machines: return the input unshifted by 115 * ignoring the upper bits of the shift count). 116 */ 117 #define upper_32_bits(X) ((uint32_t) (((X) >> 16) >> 16)) 118 #define lower_32_bits(X) ((uint32_t) ((X) & 0xffffffffUL)) 119 120 #define ARRAY_SIZE(ARRAY) __arraycount(ARRAY) 121 122 #define swap(X, Y) do \ 123 { \ 124 /* XXX Kludge for type-safety. */ \ 125 if (&(X) != &(Y)) { \ 126 CTASSERT(sizeof(X) == sizeof(Y)); \ 127 /* XXX Can't do this much better without typeof. */ \ 128 char __swap_tmp[sizeof(X)]; \ 129 (void)memcpy(__swap_tmp, &(X), sizeof(X)); \ 130 (void)memcpy(&(X), &(Y), sizeof(X)); \ 131 (void)memcpy(&(Y), __swap_tmp, sizeof(X)); \ 132 } \ 133 } while (0) 134 135 #define ACCESS_ONCE(X) ({ \ 136 typeof(X) __access_once_tmp = (X); \ 137 __insn_barrier(); \ 138 __access_once_tmp; \ 139 }) 140 141 static inline int64_t 142 abs64(int64_t x) 143 { 144 return (x < 0? (-x) : x); 145 } 146 147 static inline uintmax_t 148 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor) 149 { 150 uintmax_t q = (x / divisor); 151 uintmax_t r = (x % divisor); 152 153 return ((q * multiplier) + ((r * multiplier) / divisor)); 154 } 155 156 static int panic_timeout __unused = 0; 157 158 static inline int 159 vscnprintf(char *buf, size_t size, const char *fmt, va_list va) 160 { 161 int ret; 162 163 ret = vsnprintf(buf, size, fmt, va); 164 if (__predict_false(ret < 0)) 165 return ret; 166 if (__predict_false(size == 0)) 167 return 0; 168 if (__predict_false(size <= ret)) 169 return (size - 1); 170 171 return ret; 172 } 173 174 static inline int 175 scnprintf(char *buf, size_t size, const char *fmt, ...) 176 { 177 va_list va; 178 int ret; 179 180 va_start(va, fmt); 181 ret = vscnprintf(buf, size, fmt, va); 182 va_end(va); 183 184 return ret; 185 } 186 187 static inline int 188 kstrtol(const char *s, unsigned base, long *vp) 189 { 190 long long v; 191 192 v = strtoll(s, NULL, base); 193 if (v < LONG_MIN || LONG_MAX < v) 194 return -ERANGE; 195 *vp = v; 196 return 0; 197 } 198 199 static inline char * 200 kvasprintf(gfp_t gfp, const char *fmt, va_list va) 201 { 202 va_list tva; 203 char *str; 204 int len, len1 __diagused; 205 206 va_copy(tva, va); 207 len = vsnprintf(NULL, 0, fmt, tva); 208 va_end(tva); 209 str = kmalloc(len + 1, gfp); 210 if (str == NULL) 211 return NULL; 212 len1 = vsnprintf(str, len + 1, fmt, va); 213 KASSERT(len1 == len); 214 215 return str; 216 } 217 218 static inline char * __printflike(2,3) 219 kasprintf(gfp_t gfp, const char *fmt, ...) 220 { 221 va_list va; 222 char *str; 223 224 va_start(va, fmt); 225 str = kvasprintf(gfp, fmt, va); 226 va_end(va); 227 228 return str; 229 } 230 231 #endif /* _LINUX_KERNEL_H_ */ 232