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 
144 static inline void le16_add_cpu(__le16 *var, u16 val)
145 {
146 	*var = cpu_to_le16(le16_to_cpu(*var) + val);
147 }
148 
149 static inline void le32_add_cpu(__le32 *var, u32 val)
150 {
151 	*var = cpu_to_le32(le32_to_cpu(*var) + val);
152 }
153 
154 static 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 */
160 static 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 
168 static 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 
176 static inline void be16_add_cpu(__be16 *var, u16 val)
177 {
178 	*var = cpu_to_be16(be16_to_cpu(*var) + val);
179 }
180 
181 static inline void be32_add_cpu(__be32 *var, u32 val)
182 {
183 	*var = cpu_to_be32(be32_to_cpu(*var) + val);
184 }
185 
186 static inline void be64_add_cpu(__be64 *var, u64 val)
187 {
188 	*var = cpu_to_be64(be64_to_cpu(*var) + val);
189 }
190 
191 static inline void cpu_to_be32_array(__be32 *dst, const u32 *src, size_t len)
192 {
193 	int i;
194 
195 	for (i = 0; i < len; i++)
196 		dst[i] = cpu_to_be32(src[i]);
197 }
198 
199 static inline void be32_to_cpu_array(u32 *dst, const __be32 *src, size_t len)
200 {
201 	int i;
202 
203 	for (i = 0; i < len; i++)
204 		dst[i] = be32_to_cpu(src[i]);
205 }
206 
207 #endif /* _LINUX_BYTEORDER_GENERIC_H */
208