1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0
3 *
4 * Copyright (c) 2004 Topspin Corporation. All rights reserved.
5 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
6 *
7 * This software is available to you under a choice of one of two
8 * licenses. You may choose to be licensed under the terms of the GNU
9 * General Public License (GPL) Version 2, available from the file
10 * COPYING in the main directory of this source tree, or the
11 * OpenIB.org BSD license below:
12 *
13 * Redistribution and use in source and binary forms, with or
14 * without modification, are permitted provided that the following
15 * conditions are met:
16 *
17 * - Redistributions of source code must retain the above
18 * copyright notice, this list of conditions and the following
19 * disclaimer.
20 *
21 * - Redistributions in binary form must reproduce the above
22 * copyright notice, this list of conditions and the following
23 * disclaimer in the documentation and/or other materials
24 * provided with the distribution.
25 *
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
27 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
28 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
29 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
30 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
31 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
32 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33 * SOFTWARE.
34 */
35
36 #include <sys/cdefs.h>
37 #include <linux/string.h>
38
39 #include <rdma/ib_pack.h>
40
value_read(int offset,int size,void * structure)41 static u64 value_read(int offset, int size, void *structure)
42 {
43 switch (size) {
44 case 1: return *(u8 *) ((char *)structure + offset);
45 case 2: return be16_to_cpup((__be16 *) ((char *)structure + offset));
46 case 4: return be32_to_cpup((__be32 *) ((char *)structure + offset));
47 case 8: return be64_to_cpup((__be64 *) ((char *)structure + offset));
48 default:
49 pr_warn("Field size %d bits not handled\n", size * 8);
50 return 0;
51 }
52 }
53
54 /**
55 * ib_pack - Pack a structure into a buffer
56 * @desc:Array of structure field descriptions
57 * @desc_len:Number of entries in @desc
58 * @structure:Structure to pack from
59 * @buf:Buffer to pack into
60 *
61 * ib_pack() packs a list of structure fields into a buffer,
62 * controlled by the array of fields in @desc.
63 */
ib_pack(const struct ib_field * desc,int desc_len,void * structure,void * buf)64 void ib_pack(const struct ib_field *desc,
65 int desc_len,
66 void *structure,
67 void *buf)
68 {
69 int i;
70
71 for (i = 0; i < desc_len; ++i) {
72 if (desc[i].size_bits <= 32) {
73 int shift;
74 u32 val;
75 __be32 mask;
76 __be32 *addr;
77
78 shift = 32 - desc[i].offset_bits - desc[i].size_bits;
79 if (desc[i].struct_size_bytes)
80 val = value_read(desc[i].struct_offset_bytes,
81 desc[i].struct_size_bytes,
82 structure) << shift;
83 else
84 val = 0;
85
86 mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
87 addr = (__be32 *) buf + desc[i].offset_words;
88 *addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
89 } else if (desc[i].size_bits <= 64) {
90 int shift;
91 u64 val;
92 __be64 mask;
93 __be64 *addr;
94
95 shift = 64 - desc[i].offset_bits - desc[i].size_bits;
96 if (desc[i].struct_size_bytes)
97 val = value_read(desc[i].struct_offset_bytes,
98 desc[i].struct_size_bytes,
99 structure) << shift;
100 else
101 val = 0;
102
103 mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
104 addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
105 *addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
106 } else {
107 if (desc[i].offset_bits % 8 ||
108 desc[i].size_bits % 8) {
109 pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
110 desc[i].field_name, desc[i].size_bits);
111 }
112
113 if (desc[i].struct_size_bytes)
114 memcpy((char *)buf + desc[i].offset_words * 4 +
115 desc[i].offset_bits / 8,
116 (char *)structure + desc[i].struct_offset_bytes,
117 desc[i].size_bits / 8);
118 else
119 memset((char *)buf + desc[i].offset_words * 4 +
120 desc[i].offset_bits / 8,
121 0,
122 desc[i].size_bits / 8);
123 }
124 }
125 }
126 EXPORT_SYMBOL(ib_pack);
127
value_write(int offset,int size,u64 val,void * structure)128 static void value_write(int offset, int size, u64 val, void *structure)
129 {
130 switch (size * 8) {
131 case 8: *( u8 *) ((char *)structure + offset) = val; break;
132 case 16: *(__be16 *) ((char *)structure + offset) = cpu_to_be16(val); break;
133 case 32: *(__be32 *) ((char *)structure + offset) = cpu_to_be32(val); break;
134 case 64: *(__be64 *) ((char *)structure + offset) = cpu_to_be64(val); break;
135 default:
136 pr_warn("Field size %d bits not handled\n", size * 8);
137 }
138 }
139
140 /**
141 * ib_unpack - Unpack a buffer into a structure
142 * @desc:Array of structure field descriptions
143 * @desc_len:Number of entries in @desc
144 * @buf:Buffer to unpack from
145 * @structure:Structure to unpack into
146 *
147 * ib_pack() unpacks a list of structure fields from a buffer,
148 * controlled by the array of fields in @desc.
149 */
ib_unpack(const struct ib_field * desc,int desc_len,void * buf,void * structure)150 void ib_unpack(const struct ib_field *desc,
151 int desc_len,
152 void *buf,
153 void *structure)
154 {
155 int i;
156
157 for (i = 0; i < desc_len; ++i) {
158 if (!desc[i].struct_size_bytes)
159 continue;
160
161 if (desc[i].size_bits <= 32) {
162 int shift;
163 u32 val;
164 u32 mask;
165 __be32 *addr;
166
167 shift = 32 - desc[i].offset_bits - desc[i].size_bits;
168 mask = ((1ull << desc[i].size_bits) - 1) << shift;
169 addr = (__be32 *) buf + desc[i].offset_words;
170 val = (be32_to_cpup(addr) & mask) >> shift;
171 value_write(desc[i].struct_offset_bytes,
172 desc[i].struct_size_bytes,
173 val,
174 structure);
175 } else if (desc[i].size_bits <= 64) {
176 int shift;
177 u64 val;
178 u64 mask;
179 __be64 *addr;
180
181 shift = 64 - desc[i].offset_bits - desc[i].size_bits;
182 mask = (~0ull >> (64 - desc[i].size_bits)) << shift;
183 addr = (__be64 *) buf + desc[i].offset_words;
184 val = (be64_to_cpup(addr) & mask) >> shift;
185 value_write(desc[i].struct_offset_bytes,
186 desc[i].struct_size_bytes,
187 val,
188 structure);
189 } else {
190 if (desc[i].offset_bits % 8 ||
191 desc[i].size_bits % 8) {
192 pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
193 desc[i].field_name, desc[i].size_bits);
194 }
195
196 memcpy((char *)structure + desc[i].struct_offset_bytes,
197 (char *)buf + desc[i].offset_words * 4 +
198 desc[i].offset_bits / 8,
199 desc[i].size_bits / 8);
200 }
201 }
202 }
203 EXPORT_SYMBOL(ib_unpack);
204