1/*-
2 * Copyright (c) 2015 Mark R V Murray
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#ifndef SYS_DEV_RANDOM_UINT128_H_INCLUDED
30#define	SYS_DEV_RANDOM_UINT128_H_INCLUDED
31
32#include <sys/endian.h>
33
34/* This whole thing is a crock :-(
35 *
36 * Everyone knows you always need the __uint128_t types!
37 */
38
39#ifdef __SIZEOF_INT128__
40#define	USE_REAL_UINT128_T
41#endif
42
43#ifdef USE_REAL_UINT128_T
44typedef __uint128_t uint128_t;
45#define	UINT128_ZERO 0ULL
46#else
47typedef struct {
48	/* Ignore endianness */
49	uint64_t u128t_word0;
50	uint64_t u128t_word1;
51} uint128_t;
52static const uint128_t very_long_zero = {0UL,0UL};
53#define	UINT128_ZERO very_long_zero
54#endif
55
56static __inline void
57uint128_increment(uint128_t *big_uintp)
58{
59#ifdef USE_REAL_UINT128_T
60	(*big_uintp)++;
61#else
62	big_uintp->u128t_word0++;
63	if (big_uintp->u128t_word0 == 0UL)
64		big_uintp->u128t_word1++;
65#endif
66}
67
68static __inline void
69uint128_add64(uint128_t *big_uintp, uint64_t add)
70{
71#ifdef USE_REAL_UINT128_T
72	(*big_uintp) += add;
73#else
74	uint64_t word0p;
75
76	word0p = big_uintp->u128t_word0 + add;
77	if (word0p < big_uintp->u128t_word0)
78		big_uintp->u128t_word1++;
79	big_uintp->u128t_word0 = word0p;
80#endif
81}
82
83static __inline bool
84uint128_equals(uint128_t a, uint128_t b)
85{
86#ifdef USE_REAL_UINT128_T
87	return (a == b);
88#else
89	return (a.u128t_word0 == b.u128t_word0 &&
90	    a.u128t_word1 == b.u128t_word1);
91#endif
92}
93
94static __inline int
95uint128_is_zero(uint128_t big_uint)
96{
97	return (uint128_equals(big_uint, UINT128_ZERO));
98}
99
100static __inline uint128_t
101le128dec(const void *pp)
102{
103	const uint8_t *p = pp;
104
105#ifdef USE_REAL_UINT128_T
106	return (((uint128_t)le64dec(p + 8) << 64) | le64dec(p));
107#else
108	return ((uint128_t){
109	    .u128t_word0 = le64dec(p),
110	    .u128t_word1 = le64dec(p + 8),
111	    });
112#endif
113}
114
115static __inline void
116le128enc(void *pp, uint128_t u)
117{
118	uint8_t *p = pp;
119
120#ifdef USE_REAL_UINT128_T
121	le64enc(p, (uint64_t)(u & UINT64_MAX));
122	le64enc(p + 8, (uint64_t)(u >> 64));
123#else
124	le64enc(p, u.u128t_word0);
125	le64enc(p + 8, u.u128t_word1);
126#endif
127}
128
129#endif /* SYS_DEV_RANDOM_UINT128_H_INCLUDED */
130