xref: /openbmc/linux/drivers/infiniband/core/packer.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  * $Id: packer.c 1349 2004-12-16 21:09:43Z roland $
33  */
34 
35 #include <ib_pack.h>
36 
37 static u64 value_read(int offset, int size, void *structure)
38 {
39 	switch (size) {
40 	case 1: return                *(u8  *) (structure + offset);
41 	case 2: return be16_to_cpup((__be16 *) (structure + offset));
42 	case 4: return be32_to_cpup((__be32 *) (structure + offset));
43 	case 8: return be64_to_cpup((__be64 *) (structure + offset));
44 	default:
45 		printk(KERN_WARNING "Field size %d bits not handled\n", size * 8);
46 		return 0;
47 	}
48 }
49 
50 /**
51  * ib_pack - Pack a structure into a buffer
52  * @desc:Array of structure field descriptions
53  * @desc_len:Number of entries in @desc
54  * @structure:Structure to pack from
55  * @buf:Buffer to pack into
56  *
57  * ib_pack() packs a list of structure fields into a buffer,
58  * controlled by the array of fields in @desc.
59  */
60 void ib_pack(const struct ib_field        *desc,
61 	     int                           desc_len,
62 	     void                         *structure,
63 	     void                         *buf)
64 {
65 	int i;
66 
67 	for (i = 0; i < desc_len; ++i) {
68 		if (desc[i].size_bits <= 32) {
69 			int shift;
70 			u32 val;
71 			__be32 mask;
72 			__be32 *addr;
73 
74 			shift = 32 - desc[i].offset_bits - desc[i].size_bits;
75 			if (desc[i].struct_size_bytes)
76 				val = value_read(desc[i].struct_offset_bytes,
77 						 desc[i].struct_size_bytes,
78 						 structure) << shift;
79 			else
80 				val = 0;
81 
82 			mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
83 			addr = (__be32 *) buf + desc[i].offset_words;
84 			*addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
85 		} else if (desc[i].size_bits <= 64) {
86 			int shift;
87 			u64 val;
88 			__be64 mask;
89 			__be64 *addr;
90 
91 			shift = 64 - desc[i].offset_bits - desc[i].size_bits;
92 			if (desc[i].struct_size_bytes)
93 				val = value_read(desc[i].struct_offset_bytes,
94 						 desc[i].struct_size_bytes,
95 						 structure) << shift;
96 			else
97 				val = 0;
98 
99 			mask = cpu_to_be64(((1ull << desc[i].size_bits) - 1) << shift);
100 			addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
101 			*addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
102 		} else {
103 			if (desc[i].offset_bits % 8 ||
104 			    desc[i].size_bits   % 8) {
105 				printk(KERN_WARNING "Structure field %s of size %d "
106 				       "bits is not byte-aligned\n",
107 				       desc[i].field_name, desc[i].size_bits);
108 			}
109 
110 			if (desc[i].struct_size_bytes)
111 				memcpy(buf + desc[i].offset_words * 4 +
112 				       desc[i].offset_bits / 8,
113 				       structure + desc[i].struct_offset_bytes,
114 				       desc[i].size_bits / 8);
115 			else
116 				memset(buf + desc[i].offset_words * 4 +
117 				       desc[i].offset_bits / 8,
118 				       0,
119 				       desc[i].size_bits / 8);
120 		}
121 	}
122 }
123 EXPORT_SYMBOL(ib_pack);
124 
125 static void value_write(int offset, int size, u64 val, void *structure)
126 {
127 	switch (size * 8) {
128 	case 8:  *(    u8 *) (structure + offset) = val; break;
129 	case 16: *(__be16 *) (structure + offset) = cpu_to_be16(val); break;
130 	case 32: *(__be32 *) (structure + offset) = cpu_to_be32(val); break;
131 	case 64: *(__be64 *) (structure + offset) = cpu_to_be64(val); break;
132 	default:
133 		printk(KERN_WARNING "Field size %d bits not handled\n", size * 8);
134 	}
135 }
136 
137 /**
138  * ib_unpack - Unpack a buffer into a structure
139  * @desc:Array of structure field descriptions
140  * @desc_len:Number of entries in @desc
141  * @buf:Buffer to unpack from
142  * @structure:Structure to unpack into
143  *
144  * ib_pack() unpacks a list of structure fields from a buffer,
145  * controlled by the array of fields in @desc.
146  */
147 void ib_unpack(const struct ib_field        *desc,
148 	       int                           desc_len,
149 	       void                         *buf,
150 	       void                         *structure)
151 {
152 	int i;
153 
154 	for (i = 0; i < desc_len; ++i) {
155 		if (!desc[i].struct_size_bytes)
156 			continue;
157 
158 		if (desc[i].size_bits <= 32) {
159 			int shift;
160 			u32  val;
161 			u32  mask;
162 			__be32 *addr;
163 
164 			shift = 32 - desc[i].offset_bits - desc[i].size_bits;
165 			mask = ((1ull << desc[i].size_bits) - 1) << shift;
166 			addr = (__be32 *) buf + desc[i].offset_words;
167 			val = (be32_to_cpup(addr) & mask) >> shift;
168 			value_write(desc[i].struct_offset_bytes,
169 				    desc[i].struct_size_bytes,
170 				    val,
171 				    structure);
172 		} else if (desc[i].size_bits <= 64) {
173 			int shift;
174 			u64  val;
175 			u64  mask;
176 			__be64 *addr;
177 
178 			shift = 64 - desc[i].offset_bits - desc[i].size_bits;
179 			mask = ((1ull << desc[i].size_bits) - 1) << shift;
180 			addr = (__be64 *) buf + desc[i].offset_words;
181 			val = (be64_to_cpup(addr) & mask) >> shift;
182 			value_write(desc[i].struct_offset_bytes,
183 				    desc[i].struct_size_bytes,
184 				    val,
185 				    structure);
186 		} else {
187 			if (desc[i].offset_bits % 8 ||
188 			    desc[i].size_bits   % 8) {
189 				printk(KERN_WARNING "Structure field %s of size %d "
190 				       "bits is not byte-aligned\n",
191 				       desc[i].field_name, desc[i].size_bits);
192 			}
193 
194 			memcpy(structure + desc[i].struct_offset_bytes,
195 			       buf + desc[i].offset_words * 4 +
196 			       desc[i].offset_bits / 8,
197 			       desc[i].size_bits / 8);
198 		}
199 	}
200 }
201 EXPORT_SYMBOL(ib_unpack);
202