mem.h

  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#ifndef MEM_H_MODULE
 13#define MEM_H_MODULE
 14
 15/*-****************************************
 16*  Dependencies
 17******************************************/
 18#include <linux/unaligned.h>  /* get_unaligned, put_unaligned* */
 19#include <linux/compiler.h>  /* inline */
 20#include <linux/swab.h>  /* swab32, swab64 */
 21#include <linux/types.h>  /* size_t, ptrdiff_t */
 22#include "debug.h"  /* DEBUG_STATIC_ASSERT */
 23
 24/*-****************************************
 25*  Compiler specifics
 26******************************************/
 27#undef MEM_STATIC /* may be already defined from common/compiler.h */
 28#define MEM_STATIC static inline
 29
 30/*-**************************************************************
 31*  Basic Types
 32*****************************************************************/
 33typedef uint8_t  BYTE;
 34typedef uint8_t  U8;
 35typedef int8_t   S8;
 36typedef uint16_t U16;
 37typedef int16_t  S16;
 38typedef uint32_t U32;
 39typedef int32_t  S32;
 40typedef uint64_t U64;
 41typedef int64_t  S64;
 42
 43/*-**************************************************************
 44*  Memory I/O API
 45*****************************************************************/
 46/*=== Static platform detection ===*/
 47MEM_STATIC unsigned MEM_32bits(void);
 48MEM_STATIC unsigned MEM_64bits(void);
 49MEM_STATIC unsigned MEM_isLittleEndian(void);
 50
 51/*=== Native unaligned read/write ===*/
 52MEM_STATIC U16 MEM_read16(const void* memPtr);
 53MEM_STATIC U32 MEM_read32(const void* memPtr);
 54MEM_STATIC U64 MEM_read64(const void* memPtr);
 55MEM_STATIC size_t MEM_readST(const void* memPtr);
 56
 57MEM_STATIC void MEM_write16(void* memPtr, U16 value);
 58MEM_STATIC void MEM_write32(void* memPtr, U32 value);
 59MEM_STATIC void MEM_write64(void* memPtr, U64 value);
 60
 61/*=== Little endian unaligned read/write ===*/
 62MEM_STATIC U16 MEM_readLE16(const void* memPtr);
 63MEM_STATIC U32 MEM_readLE24(const void* memPtr);
 64MEM_STATIC U32 MEM_readLE32(const void* memPtr);
 65MEM_STATIC U64 MEM_readLE64(const void* memPtr);
 66MEM_STATIC size_t MEM_readLEST(const void* memPtr);
 67
 68MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val);
 69MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val);
 70MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32);
 71MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64);
 72MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val);
 73
 74/*=== Big endian unaligned read/write ===*/
 75MEM_STATIC U32 MEM_readBE32(const void* memPtr);
 76MEM_STATIC U64 MEM_readBE64(const void* memPtr);
 77MEM_STATIC size_t MEM_readBEST(const void* memPtr);
 78
 79MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32);
 80MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64);
 81MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val);
 82
 83/*=== Byteswap ===*/
 84MEM_STATIC U32 MEM_swap32(U32 in);
 85MEM_STATIC U64 MEM_swap64(U64 in);
 86MEM_STATIC size_t MEM_swapST(size_t in);
 87
 88/*-**************************************************************
 89*  Memory I/O Implementation
 90*****************************************************************/
 91MEM_STATIC unsigned MEM_32bits(void)
 92{
 93    return sizeof(size_t) == 4;
 94}
 95
 96MEM_STATIC unsigned MEM_64bits(void)
 97{
 98    return sizeof(size_t) == 8;
 99}
100
101#if defined(__LITTLE_ENDIAN)
102#define MEM_LITTLE_ENDIAN 1
103#else
104#define MEM_LITTLE_ENDIAN 0
105#endif
106
107MEM_STATIC unsigned MEM_isLittleEndian(void)
108{
109    return MEM_LITTLE_ENDIAN;
110}
111
112MEM_STATIC U16 MEM_read16(const void *memPtr)
113{
114    return get_unaligned((const U16 *)memPtr);
115}
116
117MEM_STATIC U32 MEM_read32(const void *memPtr)
118{
119    return get_unaligned((const U32 *)memPtr);
120}
121
122MEM_STATIC U64 MEM_read64(const void *memPtr)
123{
124    return get_unaligned((const U64 *)memPtr);
125}
126
127MEM_STATIC size_t MEM_readST(const void *memPtr)
128{
129    return get_unaligned((const size_t *)memPtr);
130}
131
132MEM_STATIC void MEM_write16(void *memPtr, U16 value)
133{
134    put_unaligned(value, (U16 *)memPtr);
135}
136
137MEM_STATIC void MEM_write32(void *memPtr, U32 value)
138{
139    put_unaligned(value, (U32 *)memPtr);
140}
141
142MEM_STATIC void MEM_write64(void *memPtr, U64 value)
143{
144    put_unaligned(value, (U64 *)memPtr);
145}
146
147/*=== Little endian r/w ===*/
148
149MEM_STATIC U16 MEM_readLE16(const void *memPtr)
150{
151    return get_unaligned_le16(memPtr);
152}
153
154MEM_STATIC void MEM_writeLE16(void *memPtr, U16 val)
155{
156    put_unaligned_le16(val, memPtr);
157}
158
159MEM_STATIC U32 MEM_readLE24(const void *memPtr)
160{
161    return MEM_readLE16(memPtr) + (((const BYTE *)memPtr)[2] << 16);
162}
163
164MEM_STATIC void MEM_writeLE24(void *memPtr, U32 val)
165{
166	MEM_writeLE16(memPtr, (U16)val);
167	((BYTE *)memPtr)[2] = (BYTE)(val >> 16);
168}
169
170MEM_STATIC U32 MEM_readLE32(const void *memPtr)
171{
172    return get_unaligned_le32(memPtr);
173}
174
175MEM_STATIC void MEM_writeLE32(void *memPtr, U32 val32)
176{
177    put_unaligned_le32(val32, memPtr);
178}
179
180MEM_STATIC U64 MEM_readLE64(const void *memPtr)
181{
182    return get_unaligned_le64(memPtr);
183}
184
185MEM_STATIC void MEM_writeLE64(void *memPtr, U64 val64)
186{
187    put_unaligned_le64(val64, memPtr);
188}
189
190MEM_STATIC size_t MEM_readLEST(const void *memPtr)
191{
192	if (MEM_32bits())
193		return (size_t)MEM_readLE32(memPtr);
194	else
195		return (size_t)MEM_readLE64(memPtr);
196}
197
198MEM_STATIC void MEM_writeLEST(void *memPtr, size_t val)
199{
200	if (MEM_32bits())
201		MEM_writeLE32(memPtr, (U32)val);
202	else
203		MEM_writeLE64(memPtr, (U64)val);
204}
205
206/*=== Big endian r/w ===*/
207
208MEM_STATIC U32 MEM_readBE32(const void *memPtr)
209{
210    return get_unaligned_be32(memPtr);
211}
212
213MEM_STATIC void MEM_writeBE32(void *memPtr, U32 val32)
214{
215    put_unaligned_be32(val32, memPtr);
216}
217
218MEM_STATIC U64 MEM_readBE64(const void *memPtr)
219{
220    return get_unaligned_be64(memPtr);
221}
222
223MEM_STATIC void MEM_writeBE64(void *memPtr, U64 val64)
224{
225    put_unaligned_be64(val64, memPtr);
226}
227
228MEM_STATIC size_t MEM_readBEST(const void *memPtr)
229{
230	if (MEM_32bits())
231		return (size_t)MEM_readBE32(memPtr);
232	else
233		return (size_t)MEM_readBE64(memPtr);
234}
235
236MEM_STATIC void MEM_writeBEST(void *memPtr, size_t val)
237{
238	if (MEM_32bits())
239		MEM_writeBE32(memPtr, (U32)val);
240	else
241		MEM_writeBE64(memPtr, (U64)val);
242}
243
244MEM_STATIC U32 MEM_swap32(U32 in)
245{
246    return swab32(in);
247}
248
249MEM_STATIC U64 MEM_swap64(U64 in)
250{
251    return swab64(in);
252}
253
254MEM_STATIC size_t MEM_swapST(size_t in)
255{
256    if (MEM_32bits())
257        return (size_t)MEM_swap32((U32)in);
258    else
259        return (size_t)MEM_swap64((U64)in);
260}
261
262#endif /* MEM_H_MODULE */