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[linux-2.6] / drivers / infiniband / core / packer.c
1 /*
2  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
3  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  *
33  * $Id: packer.c 1349 2004-12-16 21:09:43Z roland $
34  */
35
36 #include <linux/string.h>
37
38 #include <rdma/ib_pack.h>
39
40 static u64 value_read(int offset, int size, void *structure)
41 {
42         switch (size) {
43         case 1: return                *(u8  *) (structure + offset);
44         case 2: return be16_to_cpup((__be16 *) (structure + offset));
45         case 4: return be32_to_cpup((__be32 *) (structure + offset));
46         case 8: return be64_to_cpup((__be64 *) (structure + offset));
47         default:
48                 printk(KERN_WARNING "Field size %d bits not handled\n", size * 8);
49                 return 0;
50         }
51 }
52
53 /**
54  * ib_pack - Pack a structure into a buffer
55  * @desc:Array of structure field descriptions
56  * @desc_len:Number of entries in @desc
57  * @structure:Structure to pack from
58  * @buf:Buffer to pack into
59  *
60  * ib_pack() packs a list of structure fields into a buffer,
61  * controlled by the array of fields in @desc.
62  */
63 void ib_pack(const struct ib_field        *desc,
64              int                           desc_len,
65              void                         *structure,
66              void                         *buf)
67 {
68         int i;
69
70         for (i = 0; i < desc_len; ++i) {
71                 if (desc[i].size_bits <= 32) {
72                         int shift;
73                         u32 val;
74                         __be32 mask;
75                         __be32 *addr;
76
77                         shift = 32 - desc[i].offset_bits - desc[i].size_bits;
78                         if (desc[i].struct_size_bytes)
79                                 val = value_read(desc[i].struct_offset_bytes,
80                                                  desc[i].struct_size_bytes,
81                                                  structure) << shift;
82                         else
83                                 val = 0;
84
85                         mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
86                         addr = (__be32 *) buf + desc[i].offset_words;
87                         *addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
88                 } else if (desc[i].size_bits <= 64) {
89                         int shift;
90                         u64 val;
91                         __be64 mask;
92                         __be64 *addr;
93
94                         shift = 64 - desc[i].offset_bits - desc[i].size_bits;
95                         if (desc[i].struct_size_bytes)
96                                 val = value_read(desc[i].struct_offset_bytes,
97                                                  desc[i].struct_size_bytes,
98                                                  structure) << shift;
99                         else
100                                 val = 0;
101
102                         mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
103                         addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
104                         *addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
105                 } else {
106                         if (desc[i].offset_bits % 8 ||
107                             desc[i].size_bits   % 8) {
108                                 printk(KERN_WARNING "Structure field %s of size %d "
109                                        "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(buf + desc[i].offset_words * 4 +
115                                        desc[i].offset_bits / 8,
116                                        structure + desc[i].struct_offset_bytes,
117                                        desc[i].size_bits / 8);
118                         else
119                                 memset(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
128 static void value_write(int offset, int size, u64 val, void *structure)
129 {
130         switch (size * 8) {
131         case 8:  *(    u8 *) (structure + offset) = val; break;
132         case 16: *(__be16 *) (structure + offset) = cpu_to_be16(val); break;
133         case 32: *(__be32 *) (structure + offset) = cpu_to_be32(val); break;
134         case 64: *(__be64 *) (structure + offset) = cpu_to_be64(val); break;
135         default:
136                 printk(KERN_WARNING "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  */
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                                 printk(KERN_WARNING "Structure field %s of size %d "
193                                        "bits is not byte-aligned\n",
194                                        desc[i].field_name, desc[i].size_bits);
195                         }
196
197                         memcpy(structure + desc[i].struct_offset_bytes,
198                                buf + desc[i].offset_words * 4 +
199                                desc[i].offset_bits / 8,
200                                desc[i].size_bits / 8);
201                 }
202         }
203 }
204 EXPORT_SYMBOL(ib_unpack);