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
114static inline int64_t
115abs64(int64_t x)
116{
117 return (x < 0? (-x) : x);
118}
119
120static inline uintmax_t
121mult_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
129static int panic_timeout __unused = 0;
130
131static inline int
132vscnprintf(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
147static inline int
148scnprintf(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
160static inline int
161kstrtol(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