1 /* $NetBSD: kernel.h,v 1.25 2020/02/14 14:34:57 maya 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 #include <asm/byteorder.h> 43 #include <asm/div64.h> 44 45 #include <linux/bitops.h> 46 #include <linux/log2.h> 47 #include <linux/printk.h> 48 #include <linux/slab.h> 49 50 #define U16_MAX UINT16_MAX 51 #define U32_MAX UINT32_MAX 52 #define U64_MAX UINT64_MAX 53 54 #define oops_in_progress (panicstr != NULL) 55 56 #define IS_ENABLED(option) (option) 57 #define IS_BUILTIN(option) (1) /* Probably... */ 58 59 #define __printf __printflike 60 #define __user 61 #if __GNUC_PREREQ__(4,0) /* not sure when but this will work */ 62 #define __must_check __attribute__((warn_unused_result)) 63 #else 64 #define __must_check /* nothing */ 65 #endif 66 #define __always_unused __unused 67 #define noinline __noinline 68 69 #define barrier() __insn_barrier() 70 #define likely(X) __predict_true(X) 71 #define unlikely(X) __predict_false(X) 72 73 /* 74 * XXX Linux kludge to work around GCC uninitialized variable warning. 75 * Linux does `x = x', which is bollocks. 76 */ 77 #define uninitialized_var(x) x = 0 78 79 /* XXX These will multiply evaluate their arguments. */ 80 #define min(X, Y) MIN(X, Y) 81 #define max(X, Y) MAX(X, Y) 82 83 #define max_t(T, X, Y) MAX(X, Y) 84 #define min_t(T, X, Y) MIN(X, Y) 85 86 #define clamp_t(T, X, MIN, MAX) min_t(T, max_t(T, X, MIN), MAX) 87 #define clamp(X, MN, MX) MIN(MAX(X, MN), MX) 88 89 #define min3(X, Y, Z) MIN(X, MIN(Y, Z)) 90 #define max3(X, Y, Z) MAX(X, MAX(Y, Z)) 91 92 /* 93 * Rounding to nearest. 94 */ 95 #define DIV_ROUND_CLOSEST(N, D) \ 96 ((0 < (N)) ? (((N) + ((D) / 2)) / (D)) \ 97 : (((N) - ((D) / 2)) / (D))) 98 99 #define DIV_ROUND_CLOSEST_ULL(N, D) (((N) + (D)/2)/(D)) 100 101 /* 102 * Rounding to what may or may not be powers of two. 103 */ 104 #define DIV_ROUND_UP(X, N) (((X) + (N) - 1) / (N)) 105 #define DIV_ROUND_UP_ULL(X, N) DIV_ROUND_UP((unsigned long long)(X), (N)) 106 107 /* 108 * Rounding to powers of two -- carefully avoiding multiple evaluation 109 * of arguments and pitfalls with C integer arithmetic rules. 110 */ 111 #define round_up(X, N) ((((X) - 1) | ((N) - 1)) + 1) 112 #define round_down(X, N) ((X) & ~(uintmax_t)((N) - 1)) 113 114 #define IS_ALIGNED(X, N) (((X) & ((N) - 1)) == 0) 115 116 /* 117 * These select 32-bit halves of what may be 32- or 64-bit quantities, 118 * for which straight 32-bit shifts may be undefined behaviour (and do 119 * the wrong thing on most machines: return the input unshifted by 120 * ignoring the upper bits of the shift count). 121 */ 122 #define upper_32_bits(X) ((uint32_t) (((X) >> 16) >> 16)) 123 #define lower_32_bits(X) ((uint32_t) ((X) & 0xffffffffUL)) 124 125 #define ARRAY_SIZE(ARRAY) __arraycount(ARRAY) 126 127 #define swap(X, Y) do \ 128 { \ 129 /* XXX Kludge for type-safety. */ \ 130 if (&(X) != &(Y)) { \ 131 CTASSERT(sizeof(X) == sizeof(Y)); \ 132 /* XXX Can't do this much better without typeof. */ \ 133 char __swap_tmp[sizeof(X)]; \ 134 (void)memcpy(__swap_tmp, &(X), sizeof(X)); \ 135 (void)memcpy(&(X), &(Y), sizeof(X)); \ 136 (void)memcpy(&(Y), __swap_tmp, sizeof(X)); \ 137 } \ 138 } while (0) 139 140 #define ACCESS_ONCE(X) ({ \ 141 typeof(X) __access_once_tmp = (X); \ 142 __insn_barrier(); \ 143 __access_once_tmp; \ 144 }) 145 146 static __inline int64_t 147 abs64(int64_t x) 148 { 149 return (x < 0? (-x) : x); 150 } 151 152 static __inline uintmax_t 153 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor) 154 { 155 uintmax_t q = (x / divisor); 156 uintmax_t r = (x % divisor); 157 158 return ((q * multiplier) + ((r * multiplier) / divisor)); 159 } 160 161 static int panic_timeout __unused = 0; 162 163 static __inline int __printflike(3, 0) 164 vscnprintf(char *buf, size_t size, const char *fmt, va_list va) 165 { 166 int ret; 167 168 ret = vsnprintf(buf, size, fmt, va); 169 if (__predict_false(ret < 0)) 170 return ret; 171 if (__predict_false(size == 0)) 172 return 0; 173 if (__predict_false(size <= (size_t)ret)) 174 return (size - 1); 175 176 return ret; 177 } 178 179 static __inline int __printflike(3, 4) 180 scnprintf(char *buf, size_t size, const char *fmt, ...) 181 { 182 va_list va; 183 int ret; 184 185 va_start(va, fmt); 186 ret = vscnprintf(buf, size, fmt, va); 187 va_end(va); 188 189 return ret; 190 } 191 192 static __inline int 193 kstrtol(const char *s, unsigned base, long *vp) 194 { 195 long long v; 196 197 v = strtoll(s, NULL, base); 198 if (v < LONG_MIN || LONG_MAX < v) 199 return -ERANGE; 200 *vp = v; 201 return 0; 202 } 203 204 static inline long 205 simple_strtol(const char *s, char **endp, unsigned base) 206 { 207 long v; 208 209 *endp = NULL; /* paranoia */ 210 v = strtoll(s, endp, base); 211 if (v < LONG_MIN || LONG_MAX < v) 212 return 0; 213 return v; 214 } 215 216 static __inline char * __printflike(2, 0) 217 kvasprintf(gfp_t gfp, const char *fmt, va_list va) 218 { 219 va_list tva; 220 char *str; 221 int len, len1 __diagused; 222 223 va_copy(tva, va); 224 len = vsnprintf(NULL, 0, fmt, tva); 225 va_end(tva); 226 str = kmalloc(len + 1, gfp); 227 if (str == NULL) 228 return NULL; 229 len1 = vsnprintf(str, len + 1, fmt, va); 230 KASSERT(len1 == len); 231 232 return str; 233 } 234 235 static __inline char * __printflike(2, 3) 236 kasprintf(gfp_t gfp, const char *fmt, ...) 237 { 238 va_list va; 239 char *str; 240 241 va_start(va, fmt); 242 str = kvasprintf(gfp, fmt, va); 243 va_end(va); 244 245 return str; 246 } 247 248 #endif /* _LINUX_KERNEL_H_ */ 249