xref: /openbmc/linux/drivers/infiniband/core/packer.c (revision 87c2ce3b)
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);
205