xref: /dpdk/lib/eal/include/generic/rte_byteorder.h (revision daa02b5cddbb8e11b31d41e2bf7bb1ae64dcae2f)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #ifndef _RTE_BYTEORDER_H_
6 #define _RTE_BYTEORDER_H_
7 
8 /**
9  * @file
10  *
11  * Byte Swap Operations
12  *
13  * This file defines a generic API for byte swap operations. Part of
14  * the implementation is architecture-specific.
15  */
16 
17 #include <stdint.h>
18 #ifdef RTE_EXEC_ENV_FREEBSD
19 #include <sys/endian.h>
20 #elif defined RTE_EXEC_ENV_LINUX
21 #include <endian.h>
22 #endif
23 
24 #include <rte_common.h>
25 #include <rte_config.h>
26 
27 /*
28  * Compile-time endianness detection
29  */
30 #define RTE_BIG_ENDIAN    1
31 #define RTE_LITTLE_ENDIAN 2
32 #if defined __BYTE_ORDER__
33 #if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
34 #define RTE_BYTE_ORDER RTE_BIG_ENDIAN
35 #elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
36 #define RTE_BYTE_ORDER RTE_LITTLE_ENDIAN
37 #endif /* __BYTE_ORDER__ */
38 #elif defined __BYTE_ORDER
39 #if __BYTE_ORDER == __BIG_ENDIAN
40 #define RTE_BYTE_ORDER RTE_BIG_ENDIAN
41 #elif __BYTE_ORDER == __LITTLE_ENDIAN
42 #define RTE_BYTE_ORDER RTE_LITTLE_ENDIAN
43 #endif /* __BYTE_ORDER */
44 #elif defined __BIG_ENDIAN__
45 #define RTE_BYTE_ORDER RTE_BIG_ENDIAN
46 #elif defined __LITTLE_ENDIAN__
47 #define RTE_BYTE_ORDER RTE_LITTLE_ENDIAN
48 #endif
49 #if !defined(RTE_BYTE_ORDER)
50 #error Unknown endianness.
51 #endif
52 
53 #define RTE_STATIC_BSWAP16(v) \
54 	((((uint16_t)(v) & UINT16_C(0x00ff)) << 8) | \
55 	 (((uint16_t)(v) & UINT16_C(0xff00)) >> 8))
56 
57 #define RTE_STATIC_BSWAP32(v) \
58 	((((uint32_t)(v) & UINT32_C(0x000000ff)) << 24) | \
59 	 (((uint32_t)(v) & UINT32_C(0x0000ff00)) <<  8) | \
60 	 (((uint32_t)(v) & UINT32_C(0x00ff0000)) >>  8) | \
61 	 (((uint32_t)(v) & UINT32_C(0xff000000)) >> 24))
62 
63 #define RTE_STATIC_BSWAP64(v) \
64 	((((uint64_t)(v) & UINT64_C(0x00000000000000ff)) << 56) | \
65 	 (((uint64_t)(v) & UINT64_C(0x000000000000ff00)) << 40) | \
66 	 (((uint64_t)(v) & UINT64_C(0x0000000000ff0000)) << 24) | \
67 	 (((uint64_t)(v) & UINT64_C(0x00000000ff000000)) <<  8) | \
68 	 (((uint64_t)(v) & UINT64_C(0x000000ff00000000)) >>  8) | \
69 	 (((uint64_t)(v) & UINT64_C(0x0000ff0000000000)) >> 24) | \
70 	 (((uint64_t)(v) & UINT64_C(0x00ff000000000000)) >> 40) | \
71 	 (((uint64_t)(v) & UINT64_C(0xff00000000000000)) >> 56))
72 
73 /*
74  * These macros are functionally similar to rte_cpu_to_(be|le)(16|32|64)(),
75  * they take values in host CPU order and return them converted to the
76  * intended endianness.
77  *
78  * They resolve at compilation time to integer constants which can safely be
79  * used with static initializers, since those cannot involve function calls.
80  *
81  * On the other hand, they are not as optimized as their rte_cpu_to_*()
82  * counterparts, therefore applications should refrain from using them on
83  * variable values, particularly inside performance-sensitive code.
84  */
85 #if RTE_BYTE_ORDER == RTE_BIG_ENDIAN
86 #define RTE_BE16(v) (rte_be16_t)(v)
87 #define RTE_BE32(v) (rte_be32_t)(v)
88 #define RTE_BE64(v) (rte_be64_t)(v)
89 #define RTE_LE16(v) (rte_le16_t)(RTE_STATIC_BSWAP16(v))
90 #define RTE_LE32(v) (rte_le32_t)(RTE_STATIC_BSWAP32(v))
91 #define RTE_LE64(v) (rte_le64_t)(RTE_STATIC_BSWAP64(v))
92 #elif RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
93 #define RTE_BE16(v) (rte_be16_t)(RTE_STATIC_BSWAP16(v))
94 #define RTE_BE32(v) (rte_be32_t)(RTE_STATIC_BSWAP32(v))
95 #define RTE_BE64(v) (rte_be64_t)(RTE_STATIC_BSWAP64(v))
96 #define RTE_LE16(v) (rte_le16_t)(v)
97 #define RTE_LE32(v) (rte_le32_t)(v)
98 #define RTE_LE64(v) (rte_le64_t)(v)
99 #else
100 #error Unsupported endianness.
101 #endif
102 
103 /*
104  * The following types should be used when handling values according to a
105  * specific byte ordering, which may differ from that of the host CPU.
106  *
107  * Libraries, public APIs and applications are encouraged to use them for
108  * documentation purposes.
109  */
110 typedef uint16_t rte_be16_t; /**< 16-bit big-endian value. */
111 typedef uint32_t rte_be32_t; /**< 32-bit big-endian value. */
112 typedef uint64_t rte_be64_t; /**< 64-bit big-endian value. */
113 typedef uint16_t rte_le16_t; /**< 16-bit little-endian value. */
114 typedef uint32_t rte_le32_t; /**< 32-bit little-endian value. */
115 typedef uint64_t rte_le64_t; /**< 64-bit little-endian value. */
116 
117 /*
118  * An internal function to swap bytes in a 16-bit value.
119  *
120  * It is used by rte_bswap16() when the value is constant. Do not use
121  * this function directly; rte_bswap16() is preferred.
122  */
123 static inline uint16_t
124 rte_constant_bswap16(uint16_t x)
125 {
126 	return (uint16_t)RTE_STATIC_BSWAP16(x);
127 }
128 
129 /*
130  * An internal function to swap bytes in a 32-bit value.
131  *
132  * It is used by rte_bswap32() when the value is constant. Do not use
133  * this function directly; rte_bswap32() is preferred.
134  */
135 static inline uint32_t
136 rte_constant_bswap32(uint32_t x)
137 {
138 	return (uint32_t)RTE_STATIC_BSWAP32(x);
139 }
140 
141 /*
142  * An internal function to swap bytes of a 64-bit value.
143  *
144  * It is used by rte_bswap64() when the value is constant. Do not use
145  * this function directly; rte_bswap64() is preferred.
146  */
147 static inline uint64_t
148 rte_constant_bswap64(uint64_t x)
149 {
150 	return (uint64_t)RTE_STATIC_BSWAP64(x);
151 }
152 
153 
154 #ifdef __DOXYGEN__
155 
156 /**
157  * Swap bytes in a 16-bit value.
158  */
159 static uint16_t rte_bswap16(uint16_t _x);
160 
161 /**
162  * Swap bytes in a 32-bit value.
163  */
164 static uint32_t rte_bswap32(uint32_t x);
165 
166 /**
167  * Swap bytes in a 64-bit value.
168  */
169 static uint64_t rte_bswap64(uint64_t x);
170 
171 /**
172  * Convert a 16-bit value from CPU order to little endian.
173  */
174 static rte_le16_t rte_cpu_to_le_16(uint16_t x);
175 
176 /**
177  * Convert a 32-bit value from CPU order to little endian.
178  */
179 static rte_le32_t rte_cpu_to_le_32(uint32_t x);
180 
181 /**
182  * Convert a 64-bit value from CPU order to little endian.
183  */
184 static rte_le64_t rte_cpu_to_le_64(uint64_t x);
185 
186 
187 /**
188  * Convert a 16-bit value from CPU order to big endian.
189  */
190 static rte_be16_t rte_cpu_to_be_16(uint16_t x);
191 
192 /**
193  * Convert a 32-bit value from CPU order to big endian.
194  */
195 static rte_be32_t rte_cpu_to_be_32(uint32_t x);
196 
197 /**
198  * Convert a 64-bit value from CPU order to big endian.
199  */
200 static rte_be64_t rte_cpu_to_be_64(uint64_t x);
201 
202 
203 /**
204  * Convert a 16-bit value from little endian to CPU order.
205  */
206 static uint16_t rte_le_to_cpu_16(rte_le16_t x);
207 
208 /**
209  * Convert a 32-bit value from little endian to CPU order.
210  */
211 static uint32_t rte_le_to_cpu_32(rte_le32_t x);
212 
213 /**
214  * Convert a 64-bit value from little endian to CPU order.
215  */
216 static uint64_t rte_le_to_cpu_64(rte_le64_t x);
217 
218 
219 /**
220  * Convert a 16-bit value from big endian to CPU order.
221  */
222 static uint16_t rte_be_to_cpu_16(rte_be16_t x);
223 
224 /**
225  * Convert a 32-bit value from big endian to CPU order.
226  */
227 static uint32_t rte_be_to_cpu_32(rte_be32_t x);
228 
229 /**
230  * Convert a 64-bit value from big endian to CPU order.
231  */
232 static uint64_t rte_be_to_cpu_64(rte_be64_t x);
233 
234 #endif /* __DOXYGEN__ */
235 
236 #ifdef RTE_FORCE_INTRINSICS
237 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)
238 #define rte_bswap16(x) __builtin_bswap16(x)
239 #endif
240 
241 #define rte_bswap32(x) __builtin_bswap32(x)
242 
243 #define rte_bswap64(x) __builtin_bswap64(x)
244 
245 #endif
246 
247 #endif /* _RTE_BYTEORDER_H_ */
248