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 
34 #include <linux/export.h>
35 #include <linux/string.h>
36 
37 #include <rdma/ib_pack.h>
38 
value_read(int offset,int size,void * structure)39 static u64 value_read(int offset, int size, void *structure)
40 {
41 	switch (size) {
42 	case 1: return                *(u8  *) (structure + offset);
43 	case 2: return be16_to_cpup((__be16 *) (structure + offset));
44 	case 4: return be32_to_cpup((__be32 *) (structure + offset));
45 	case 8: return be64_to_cpup((__be64 *) (structure + offset));
46 	default:
47 		pr_warn("Field size %d bits not handled\n", size * 8);
48 		return 0;
49 	}
50 }
51 
52 /**
53  * ib_pack - Pack a structure into a buffer
54  * @desc:Array of structure field descriptions
55  * @desc_len:Number of entries in @desc
56  * @structure:Structure to pack from
57  * @buf:Buffer to pack into
58  *
59  * ib_pack() packs a list of structure fields into a buffer,
60  * controlled by the array of fields in @desc.
61  */
ib_pack(const struct ib_field * desc,int desc_len,void * structure,void * buf)62 void ib_pack(const struct ib_field        *desc,
63 	     int                           desc_len,
64 	     void                         *structure,
65 	     void                         *buf)
66 {
67 	int i;
68 
69 	for (i = 0; i < desc_len; ++i) {
70 		if (desc[i].size_bits <= 32) {
71 			int shift;
72 			u32 val;
73 			__be32 mask;
74 			__be32 *addr;
75 
76 			shift = 32 - desc[i].offset_bits - desc[i].size_bits;
77 			if (desc[i].struct_size_bytes)
78 				val = value_read(desc[i].struct_offset_bytes,
79 						 desc[i].struct_size_bytes,
80 						 structure) << shift;
81 			else
82 				val = 0;
83 
84 			mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
85 			addr = (__be32 *) buf + desc[i].offset_words;
86 			*addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
87 		} else if (desc[i].size_bits <= 64) {
88 			int shift;
89 			u64 val;
90 			__be64 mask;
91 			__be64 *addr;
92 
93 			shift = 64 - desc[i].offset_bits - desc[i].size_bits;
94 			if (desc[i].struct_size_bytes)
95 				val = value_read(desc[i].struct_offset_bytes,
96 						 desc[i].struct_size_bytes,
97 						 structure) << shift;
98 			else
99 				val = 0;
100 
101 			mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
102 			addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
103 			*addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
104 		} else {
105 			if (desc[i].offset_bits % 8 ||
106 			    desc[i].size_bits   % 8) {
107 				pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
108 					desc[i].field_name, desc[i].size_bits);
109 			}
110 
111 			if (desc[i].struct_size_bytes)
112 				memcpy(buf + desc[i].offset_words * 4 +
113 				       desc[i].offset_bits / 8,
114 				       structure + desc[i].struct_offset_bytes,
115 				       desc[i].size_bits / 8);
116 			else
117 				memset(buf + desc[i].offset_words * 4 +
118 				       desc[i].offset_bits / 8,
119 				       0,
120 				       desc[i].size_bits / 8);
121 		}
122 	}
123 }
124 EXPORT_SYMBOL(ib_pack);
125 
value_write(int offset,int size,u64 val,void * structure)126 static void value_write(int offset, int size, u64 val, void *structure)
127 {
128 	switch (size * 8) {
129 	case 8:  *(    u8 *) (structure + offset) = val; break;
130 	case 16: *(__be16 *) (structure + offset) = cpu_to_be16(val); break;
131 	case 32: *(__be32 *) (structure + offset) = cpu_to_be32(val); break;
132 	case 64: *(__be64 *) (structure + offset) = cpu_to_be64(val); break;
133 	default:
134 		pr_warn("Field size %d bits not handled\n", size * 8);
135 	}
136 }
137 
138 /**
139  * ib_unpack - Unpack a buffer into a structure
140  * @desc:Array of structure field descriptions
141  * @desc_len:Number of entries in @desc
142  * @buf:Buffer to unpack from
143  * @structure:Structure to unpack into
144  *
145  * ib_pack() unpacks a list of structure fields from a buffer,
146  * controlled by the array of fields in @desc.
147  */
ib_unpack(const struct ib_field * desc,int desc_len,void * buf,void * structure)148 void ib_unpack(const struct ib_field        *desc,
149 	       int                           desc_len,
150 	       void                         *buf,
151 	       void                         *structure)
152 {
153 	int i;
154 
155 	for (i = 0; i < desc_len; ++i) {
156 		if (!desc[i].struct_size_bytes)
157 			continue;
158 
159 		if (desc[i].size_bits <= 32) {
160 			int shift;
161 			u32  val;
162 			u32  mask;
163 			__be32 *addr;
164 
165 			shift = 32 - desc[i].offset_bits - desc[i].size_bits;
166 			mask = ((1ull << desc[i].size_bits) - 1) << shift;
167 			addr = (__be32 *) buf + desc[i].offset_words;
168 			val = (be32_to_cpup(addr) & mask) >> shift;
169 			value_write(desc[i].struct_offset_bytes,
170 				    desc[i].struct_size_bytes,
171 				    val,
172 				    structure);
173 		} else if (desc[i].size_bits <= 64) {
174 			int shift;
175 			u64  val;
176 			u64  mask;
177 			__be64 *addr;
178 
179 			shift = 64 - desc[i].offset_bits - desc[i].size_bits;
180 			mask = (~0ull >> (64 - desc[i].size_bits)) << shift;
181 			addr = (__be64 *) buf + desc[i].offset_words;
182 			val = (be64_to_cpup(addr) & mask) >> shift;
183 			value_write(desc[i].struct_offset_bytes,
184 				    desc[i].struct_size_bytes,
185 				    val,
186 				    structure);
187 		} else {
188 			if (desc[i].offset_bits % 8 ||
189 			    desc[i].size_bits   % 8) {
190 				pr_warn("Structure field %s of size %d 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