1 /* $NetBSD: kernel.h,v 1.26 2020/10/19 11:49:56 jmcneill 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 #include <sys/endian.h> 40 41 #include <lib/libkern/libkern.h> 42 43 #include <asm/byteorder.h> 44 #include <asm/div64.h> 45 46 #include <linux/bitops.h> 47 #include <linux/log2.h> 48 #include <linux/printk.h> 49 #include <linux/slab.h> 50 51 #define U16_MAX UINT16_MAX 52 #define U32_MAX UINT32_MAX 53 #define U64_MAX UINT64_MAX 54 55 #define oops_in_progress (panicstr != NULL) 56 57 #if BYTE_ORDER == BIG_ENDIAN 58 #define __BIG_ENDIAN _BIG_ENDIAN 59 #else 60 #define __LITTLE_ENDIAN _LITTLE_ENDIAN 61 #endif 62 63 #define IS_ENABLED(option) (option) 64 #define IS_BUILTIN(option) (1) /* Probably... */ 65 66 #define __printf __printflike 67 #define __user 68 #if __GNUC_PREREQ__(4,0) /* not sure when but this will work */ 69 #define __must_check __attribute__((warn_unused_result)) 70 #else 71 #define __must_check /* nothing */ 72 #endif 73 #define __always_unused __unused 74 #define noinline __noinline 75 76 #define barrier() __insn_barrier() 77 #define likely(X) __predict_true(X) 78 #define unlikely(X) __predict_false(X) 79 80 /* 81 * XXX Linux kludge to work around GCC uninitialized variable warning. 82 * Linux does `x = x', which is bollocks. 83 */ 84 #define uninitialized_var(x) x = 0 85 86 /* XXX These will multiply evaluate their arguments. */ 87 #define min(X, Y) MIN(X, Y) 88 #define max(X, Y) MAX(X, Y) 89 90 #define max_t(T, X, Y) MAX(X, Y) 91 #define min_t(T, X, Y) MIN(X, Y) 92 93 #define clamp_t(T, X, MIN, MAX) min_t(T, max_t(T, X, MIN), MAX) 94 #define clamp(X, MN, MX) MIN(MAX(X, MN), MX) 95 96 #define min3(X, Y, Z) MIN(X, MIN(Y, Z)) 97 #define max3(X, Y, Z) MAX(X, MAX(Y, Z)) 98 99 /* 100 * Rounding to nearest. 101 */ 102 #define DIV_ROUND_CLOSEST(N, D) \ 103 ((0 < (N)) ? (((N) + ((D) / 2)) / (D)) \ 104 : (((N) - ((D) / 2)) / (D))) 105 106 #define DIV_ROUND_CLOSEST_ULL(N, D) (((N) + (D)/2)/(D)) 107 108 /* 109 * Rounding to what may or may not be powers of two. 110 */ 111 #define DIV_ROUND_UP(X, N) (((X) + (N) - 1) / (N)) 112 #define DIV_ROUND_UP_ULL(X, N) DIV_ROUND_UP((unsigned long long)(X), (N)) 113 114 /* 115 * Rounding to powers of two -- carefully avoiding multiple evaluation 116 * of arguments and pitfalls with C integer arithmetic rules. 117 */ 118 #define round_up(X, N) ((((X) - 1) | ((N) - 1)) + 1) 119 #define round_down(X, N) ((X) & ~(uintmax_t)((N) - 1)) 120 121 #define IS_ALIGNED(X, N) (((X) & ((N) - 1)) == 0) 122 123 /* 124 * These select 32-bit halves of what may be 32- or 64-bit quantities, 125 * for which straight 32-bit shifts may be undefined behaviour (and do 126 * the wrong thing on most machines: return the input unshifted by 127 * ignoring the upper bits of the shift count). 128 */ 129 #define upper_32_bits(X) ((uint32_t) (((X) >> 16) >> 16)) 130 #define lower_32_bits(X) ((uint32_t) ((X) & 0xffffffffUL)) 131 132 #define ARRAY_SIZE(ARRAY) __arraycount(ARRAY) 133 134 #define swap(X, Y) do \ 135 { \ 136 /* XXX Kludge for type-safety. */ \ 137 if (&(X) != &(Y)) { \ 138 CTASSERT(sizeof(X) == sizeof(Y)); \ 139 /* XXX Can't do this much better without typeof. */ \ 140 char __swap_tmp[sizeof(X)]; \ 141 (void)memcpy(__swap_tmp, &(X), sizeof(X)); \ 142 (void)memcpy(&(X), &(Y), sizeof(X)); \ 143 (void)memcpy(&(Y), __swap_tmp, sizeof(X)); \ 144 } \ 145 } while (0) 146 147 #define ACCESS_ONCE(X) ({ \ 148 typeof(X) __access_once_tmp = (X); \ 149 __insn_barrier(); \ 150 __access_once_tmp; \ 151 }) 152 153 static __inline int64_t 154 abs64(int64_t x) 155 { 156 return (x < 0? (-x) : x); 157 } 158 159 static __inline uintmax_t 160 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor) 161 { 162 uintmax_t q = (x / divisor); 163 uintmax_t r = (x % divisor); 164 165 return ((q * multiplier) + ((r * multiplier) / divisor)); 166 } 167 168 static int panic_timeout __unused = 0; 169 170 static __inline int __printflike(3, 0) 171 vscnprintf(char *buf, size_t size, const char *fmt, va_list va) 172 { 173 int ret; 174 175 ret = vsnprintf(buf, size, fmt, va); 176 if (__predict_false(ret < 0)) 177 return ret; 178 if (__predict_false(size == 0)) 179 return 0; 180 if (__predict_false(size <= (size_t)ret)) 181 return (size - 1); 182 183 return ret; 184 } 185 186 static __inline int __printflike(3, 4) 187 scnprintf(char *buf, size_t size, const char *fmt, ...) 188 { 189 va_list va; 190 int ret; 191 192 va_start(va, fmt); 193 ret = vscnprintf(buf, size, fmt, va); 194 va_end(va); 195 196 return ret; 197 } 198 199 static __inline int 200 kstrtol(const char *s, unsigned base, long *vp) 201 { 202 long long v; 203 204 v = strtoll(s, NULL, base); 205 if (v < LONG_MIN || LONG_MAX < v) 206 return -ERANGE; 207 *vp = v; 208 return 0; 209 } 210 211 static inline long 212 simple_strtol(const char *s, char **endp, unsigned base) 213 { 214 long v; 215 216 *endp = NULL; /* paranoia */ 217 v = strtoll(s, endp, base); 218 if (v < LONG_MIN || LONG_MAX < v) 219 return 0; 220 return v; 221 } 222 223 static __inline char * __printflike(2, 0) 224 kvasprintf(gfp_t gfp, const char *fmt, va_list va) 225 { 226 va_list tva; 227 char *str; 228 int len, len1 __diagused; 229 230 va_copy(tva, va); 231 len = vsnprintf(NULL, 0, fmt, tva); 232 va_end(tva); 233 str = kmalloc(len + 1, gfp); 234 if (str == NULL) 235 return NULL; 236 len1 = vsnprintf(str, len + 1, fmt, va); 237 KASSERT(len1 == len); 238 239 return str; 240 } 241 242 static __inline char * __printflike(2, 3) 243 kasprintf(gfp_t gfp, const char *fmt, ...) 244 { 245 va_list va; 246 char *str; 247 248 va_start(va, fmt); 249 str = kvasprintf(gfp, fmt, va); 250 va_end(va); 251 252 return str; 253 } 254 255 #endif /* _LINUX_KERNEL_H_ */ 256