generic.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _LINUX_BYTEORDER_GENERIC_H
  3#define _LINUX_BYTEORDER_GENERIC_H
  4
  5/*
  6 * linux/byteorder/generic.h
  7 * Generic Byte-reordering support
  8 *
  9 * The "... p" macros, like le64_to_cpup, can be used with pointers
 10 * to unaligned data, but there will be a performance penalty on 
 11 * some architectures.  Use get_unaligned for unaligned data.
 12 *
 13 * Francois-Rene Rideau <fare@tunes.org> 19970707
 14 *    gathered all the good ideas from all asm-foo/byteorder.h into one file,
 15 *    cleaned them up.
 16 *    I hope it is compliant with non-GCC compilers.
 17 *    I decided to put __BYTEORDER_HAS_U64__ in byteorder.h,
 18 *    because I wasn't sure it would be ok to put it in types.h
 19 *    Upgraded it to 2.1.43
 20 * Francois-Rene Rideau <fare@tunes.org> 19971012
 21 *    Upgraded it to 2.1.57
 22 *    to please Linus T., replaced huge #ifdef's between little/big endian
 23 *    by nestedly #include'd files.
 24 * Francois-Rene Rideau <fare@tunes.org> 19971205
 25 *    Made it to 2.1.71; now a facelift:
 26 *    Put files under include/linux/byteorder/
 27 *    Split swab from generic support.
 28 *
 29 * TODO:
 30 *   = Regular kernel maintainers could also replace all these manual
 31 *    byteswap macros that remain, disseminated among drivers,
 32 *    after some grep or the sources...
 33 *   = Linus might want to rename all these macros and files to fit his taste,
 34 *    to fit his personal naming scheme.
 35 *   = it seems that a few drivers would also appreciate
 36 *    nybble swapping support...
 37 *   = every architecture could add their byteswap macro in asm/byteorder.h
 38 *    see how some architectures already do (i386, alpha, ppc, etc)
 39 *   = cpu_to_beXX and beXX_to_cpu might some day need to be well
 40 *    distinguished throughout the kernel. This is not the case currently,
 41 *    since little endian, big endian, and pdp endian machines needn't it.
 42 *    But this might be the case for, say, a port of Linux to 20/21 bit
 43 *    architectures (and F21 Linux addict around?).
 44 */
 45
 46/*
 47 * The following macros are to be defined by <asm/byteorder.h>:
 48 *
 49 * Conversion of long and short int between network and host format
 50 *	ntohl(__u32 x)
 51 *	ntohs(__u16 x)
 52 *	htonl(__u32 x)
 53 *	htons(__u16 x)
 54 * It seems that some programs (which? where? or perhaps a standard? POSIX?)
 55 * might like the above to be functions, not macros (why?).
 56 * if that's true, then detect them, and take measures.
 57 * Anyway, the measure is: define only ___ntohl as a macro instead,
 58 * and in a separate file, have
 59 * unsigned long inline ntohl(x){return ___ntohl(x);}
 60 *
 61 * The same for constant arguments
 62 *	__constant_ntohl(__u32 x)
 63 *	__constant_ntohs(__u16 x)
 64 *	__constant_htonl(__u32 x)
 65 *	__constant_htons(__u16 x)
 66 *
 67 * Conversion of XX-bit integers (16- 32- or 64-)
 68 * between native CPU format and little/big endian format
 69 * 64-bit stuff only defined for proper architectures
 70 *	cpu_to_[bl]eXX(__uXX x)
 71 *	[bl]eXX_to_cpu(__uXX x)
 72 *
 73 * The same, but takes a pointer to the value to convert
 74 *	cpu_to_[bl]eXXp(__uXX x)
 75 *	[bl]eXX_to_cpup(__uXX x)
 76 *
 77 * The same, but change in situ
 78 *	cpu_to_[bl]eXXs(__uXX x)
 79 *	[bl]eXX_to_cpus(__uXX x)
 80 *
 81 * See asm-foo/byteorder.h for examples of how to provide
 82 * architecture-optimized versions
 83 *
 84 */
 85
 86#define cpu_to_le64 __cpu_to_le64
 87#define le64_to_cpu __le64_to_cpu
 88#define cpu_to_le32 __cpu_to_le32
 89#define le32_to_cpu __le32_to_cpu
 90#define cpu_to_le16 __cpu_to_le16
 91#define le16_to_cpu __le16_to_cpu
 92#define cpu_to_be64 __cpu_to_be64
 93#define be64_to_cpu __be64_to_cpu
 94#define cpu_to_be32 __cpu_to_be32
 95#define be32_to_cpu __be32_to_cpu
 96#define cpu_to_be16 __cpu_to_be16
 97#define be16_to_cpu __be16_to_cpu
 98#define cpu_to_le64p __cpu_to_le64p
 99#define le64_to_cpup __le64_to_cpup
100#define cpu_to_le32p __cpu_to_le32p
101#define le32_to_cpup __le32_to_cpup
102#define cpu_to_le16p __cpu_to_le16p
103#define le16_to_cpup __le16_to_cpup
104#define cpu_to_be64p __cpu_to_be64p
105#define be64_to_cpup __be64_to_cpup
106#define cpu_to_be32p __cpu_to_be32p
107#define be32_to_cpup __be32_to_cpup
108#define cpu_to_be16p __cpu_to_be16p
109#define be16_to_cpup __be16_to_cpup
110#define cpu_to_le64s __cpu_to_le64s
111#define le64_to_cpus __le64_to_cpus
112#define cpu_to_le32s __cpu_to_le32s
113#define le32_to_cpus __le32_to_cpus
114#define cpu_to_le16s __cpu_to_le16s
115#define le16_to_cpus __le16_to_cpus
116#define cpu_to_be64s __cpu_to_be64s
117#define be64_to_cpus __be64_to_cpus
118#define cpu_to_be32s __cpu_to_be32s
119#define be32_to_cpus __be32_to_cpus
120#define cpu_to_be16s __cpu_to_be16s
121#define be16_to_cpus __be16_to_cpus
122
123/*
124 * They have to be macros in order to do the constant folding
125 * correctly - if the argument passed into a inline function
126 * it is no longer constant according to gcc..
127 */
128
129#undef ntohl
130#undef ntohs
131#undef htonl
132#undef htons
133
134#define ___htonl(x) __cpu_to_be32(x)
135#define ___htons(x) __cpu_to_be16(x)
136#define ___ntohl(x) __be32_to_cpu(x)
137#define ___ntohs(x) __be16_to_cpu(x)
138
139#define htonl(x) ___htonl(x)
140#define ntohl(x) ___ntohl(x)
141#define htons(x) ___htons(x)
142#define ntohs(x) ___ntohs(x)
143
144static inline void le16_add_cpu(__le16 *var, u16 val)
145{
146	*var = cpu_to_le16(le16_to_cpu(*var) + val);
147}
148
149static inline void le32_add_cpu(__le32 *var, u32 val)
150{
151	*var = cpu_to_le32(le32_to_cpu(*var) + val);
152}
153
154static inline void le64_add_cpu(__le64 *var, u64 val)
155{
156	*var = cpu_to_le64(le64_to_cpu(*var) + val);
157}
158
159/* XXX: this stuff can be optimized */
160static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
161{
162	while (words--) {
163		__le32_to_cpus(buf);
164		buf++;
165	}
166}
167
168static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
169{
170	while (words--) {
171		__cpu_to_le32s(buf);
172		buf++;
173	}
174}
175
176static inline void le64_to_cpu_array(u64 *buf, unsigned int words)
177{
178	while (words--) {
179		__le64_to_cpus(buf);
180		buf++;
181	}
182}
183
184static inline void cpu_to_le64_array(u64 *buf, unsigned int words)
185{
186	while (words--) {
187		__cpu_to_le64s(buf);
188		buf++;
189	}
190}
191
192static inline void memcpy_from_le32(u32 *dst, const __le32 *src, size_t words)
193{
194	size_t i;
195
196	for (i = 0; i < words; i++)
197		dst[i] = le32_to_cpu(src[i]);
198}
199
200static inline void memcpy_to_le32(__le32 *dst, const u32 *src, size_t words)
201{
202	size_t i;
203
204	for (i = 0; i < words; i++)
205		dst[i] = cpu_to_le32(src[i]);
206}
207
208static inline void be16_add_cpu(__be16 *var, u16 val)
209{
210	*var = cpu_to_be16(be16_to_cpu(*var) + val);
211}
212
213static inline void be32_add_cpu(__be32 *var, u32 val)
214{
215	*var = cpu_to_be32(be32_to_cpu(*var) + val);
216}
217
218static inline void be64_add_cpu(__be64 *var, u64 val)
219{
220	*var = cpu_to_be64(be64_to_cpu(*var) + val);
221}
222
223static inline void cpu_to_be32_array(__be32 *dst, const u32 *src, size_t len)
224{
225	size_t i;
226
227	for (i = 0; i < len; i++)
228		dst[i] = cpu_to_be32(src[i]);
229}
230
231static inline void be32_to_cpu_array(u32 *dst, const __be32 *src, size_t len)
232{
233	size_t i;
234
235	for (i = 0; i < len; i++)
236		dst[i] = be32_to_cpu(src[i]);
237}
238
239#endif /* _LINUX_BYTEORDER_GENERIC_H */