1/* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */
2/*
3 * Copyright (c) Meta Platforms, Inc. and affiliates.
4 * All rights reserved.
5 *
6 * This source code is licensed under both the BSD-style license (found in the
7 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
8 * in the COPYING file in the root directory of this source tree).
9 * You may select, at your option, one of the above-listed licenses.
10 */
11
12/*
13 * This file provides common libc dependencies that zstd requires.
14 * The purpose is to allow replacing this file with a custom implementation
15 * to compile zstd without libc support.
16 */
17
18/* Need:
19 * NULL
20 * INT_MAX
21 * UINT_MAX
22 * ZSTD_memcpy()
23 * ZSTD_memset()
24 * ZSTD_memmove()
25 */
26#ifndef ZSTD_DEPS_COMMON
27#define ZSTD_DEPS_COMMON
28
29#include <linux/limits.h>
30#include <linux/stddef.h>
31
32#define ZSTD_memcpy(d,s,n) __builtin_memcpy((d),(s),(n))
33#define ZSTD_memmove(d,s,n) __builtin_memmove((d),(s),(n))
34#define ZSTD_memset(d,s,n) __builtin_memset((d),(s),(n))
35
36#endif /* ZSTD_DEPS_COMMON */
37
38/*
39 * Define malloc as always failing. That means the user must
40 * either use ZSTD_customMem or statically allocate memory.
41 * Need:
42 * ZSTD_malloc()
43 * ZSTD_free()
44 * ZSTD_calloc()
45 */
46#ifdef ZSTD_DEPS_NEED_MALLOC
47#ifndef ZSTD_DEPS_MALLOC
48#define ZSTD_DEPS_MALLOC
49
50#define ZSTD_malloc(s) ({ (void)(s); NULL; })
51#define ZSTD_free(p) ((void)(p))
52#define ZSTD_calloc(n,s) ({ (void)(n); (void)(s); NULL; })
53
54#endif /* ZSTD_DEPS_MALLOC */
55#endif /* ZSTD_DEPS_NEED_MALLOC */
56
57/*
58 * Provides 64-bit math support.
59 * Need:
60 * U64 ZSTD_div64(U64 dividend, U32 divisor)
61 */
62#ifdef ZSTD_DEPS_NEED_MATH64
63#ifndef ZSTD_DEPS_MATH64
64#define ZSTD_DEPS_MATH64
65
66#include <linux/math64.h>
67
68static uint64_t ZSTD_div64(uint64_t dividend, uint32_t divisor) {
69 return div_u64(dividend, divisor);
70}
71
72#endif /* ZSTD_DEPS_MATH64 */
73#endif /* ZSTD_DEPS_NEED_MATH64 */
74
75/*
76 * This is only requested when DEBUGLEVEL >= 1, meaning
77 * it is disabled in production.
78 * Need:
79 * assert()
80 */
81#ifdef ZSTD_DEPS_NEED_ASSERT
82#ifndef ZSTD_DEPS_ASSERT
83#define ZSTD_DEPS_ASSERT
84
85#include <linux/kernel.h>
86
87#define assert(x) WARN_ON(!(x))
88
89#endif /* ZSTD_DEPS_ASSERT */
90#endif /* ZSTD_DEPS_NEED_ASSERT */
91
92/*
93 * This is only requested when DEBUGLEVEL >= 2, meaning
94 * it is disabled in production.
95 * Need:
96 * ZSTD_DEBUG_PRINT()
97 */
98#ifdef ZSTD_DEPS_NEED_IO
99#ifndef ZSTD_DEPS_IO
100#define ZSTD_DEPS_IO
101
102#include <linux/printk.h>
103
104#define ZSTD_DEBUG_PRINT(...) pr_debug(__VA_ARGS__)
105
106#endif /* ZSTD_DEPS_IO */
107#endif /* ZSTD_DEPS_NEED_IO */
108
109/*
110 * Only requested when MSAN is enabled.
111 * Need:
112 * intptr_t
113 */
114#ifdef ZSTD_DEPS_NEED_STDINT
115#ifndef ZSTD_DEPS_STDINT
116#define ZSTD_DEPS_STDINT
117
118/* intptr_t already provided by ZSTD_DEPS_COMMON */
119
120#endif /* ZSTD_DEPS_STDINT */
121#endif /* ZSTD_DEPS_NEED_STDINT */
122