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 __FBSDID("$FreeBSD$");
38 
39 #include <linux/string.h>
40 
41 #include <rdma/ib_pack.h>
42 
43 static u64 value_read(int offset, int size, void *structure)
44 {
45 	switch (size) {
46 	case 1: return                *(u8  *) ((char *)structure + offset);
47 	case 2: return be16_to_cpup((__be16 *) ((char *)structure + offset));
48 	case 4: return be32_to_cpup((__be32 *) ((char *)structure + offset));
49 	case 8: return be64_to_cpup((__be64 *) ((char *)structure + offset));
50 	default:
51 		pr_warn("Field size %d bits not handled\n", size * 8);
52 		return 0;
53 	}
54 }
55 
56 /**
57  * ib_pack - Pack a structure into a buffer
58  * @desc:Array of structure field descriptions
59  * @desc_len:Number of entries in @desc
60  * @structure:Structure to pack from
61  * @buf:Buffer to pack into
62  *
63  * ib_pack() packs a list of structure fields into a buffer,
64  * controlled by the array of fields in @desc.
65  */
66 void ib_pack(const struct ib_field        *desc,
67 	     int                           desc_len,
68 	     void                         *structure,
69 	     void                         *buf)
70 {
71 	int i;
72 
73 	for (i = 0; i < desc_len; ++i) {
74 		if (desc[i].size_bits <= 32) {
75 			int shift;
76 			u32 val;
77 			__be32 mask;
78 			__be32 *addr;
79 
80 			shift = 32 - desc[i].offset_bits - desc[i].size_bits;
81 			if (desc[i].struct_size_bytes)
82 				val = value_read(desc[i].struct_offset_bytes,
83 						 desc[i].struct_size_bytes,
84 						 structure) << shift;
85 			else
86 				val = 0;
87 
88 			mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
89 			addr = (__be32 *) buf + desc[i].offset_words;
90 			*addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
91 		} else if (desc[i].size_bits <= 64) {
92 			int shift;
93 			u64 val;
94 			__be64 mask;
95 			__be64 *addr;
96 
97 			shift = 64 - desc[i].offset_bits - desc[i].size_bits;
98 			if (desc[i].struct_size_bytes)
99 				val = value_read(desc[i].struct_offset_bytes,
100 						 desc[i].struct_size_bytes,
101 						 structure) << shift;
102 			else
103 				val = 0;
104 
105 			mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
106 			addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
107 			*addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
108 		} else {
109 			if (desc[i].offset_bits % 8 ||
110 			    desc[i].size_bits   % 8) {
111 				pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
112 					desc[i].field_name, desc[i].size_bits);
113 			}
114 
115 			if (desc[i].struct_size_bytes)
116 				memcpy((char *)buf + desc[i].offset_words * 4 +
117 				       desc[i].offset_bits / 8,
118 				       (char *)structure + desc[i].struct_offset_bytes,
119 				       desc[i].size_bits / 8);
120 			else
121 				memset((char *)buf + desc[i].offset_words * 4 +
122 				       desc[i].offset_bits / 8,
123 				       0,
124 				       desc[i].size_bits / 8);
125 		}
126 	}
127 }
128 EXPORT_SYMBOL(ib_pack);
129 
130 static void value_write(int offset, int size, u64 val, void *structure)
131 {
132 	switch (size * 8) {
133 	case 8:  *(    u8 *) ((char *)structure + offset) = val; break;
134 	case 16: *(__be16 *) ((char *)structure + offset) = cpu_to_be16(val); break;
135 	case 32: *(__be32 *) ((char *)structure + offset) = cpu_to_be32(val); break;
136 	case 64: *(__be64 *) ((char *)structure + offset) = cpu_to_be64(val); break;
137 	default:
138 		pr_warn("Field size %d bits not handled\n", size * 8);
139 	}
140 }
141 
142 /**
143  * ib_unpack - Unpack a buffer into a structure
144  * @desc:Array of structure field descriptions
145  * @desc_len:Number of entries in @desc
146  * @buf:Buffer to unpack from
147  * @structure:Structure to unpack into
148  *
149  * ib_pack() unpacks a list of structure fields from a buffer,
150  * controlled by the array of fields in @desc.
151  */
152 void ib_unpack(const struct ib_field        *desc,
153 	       int                           desc_len,
154 	       void                         *buf,
155 	       void                         *structure)
156 {
157 	int i;
158 
159 	for (i = 0; i < desc_len; ++i) {
160 		if (!desc[i].struct_size_bytes)
161 			continue;
162 
163 		if (desc[i].size_bits <= 32) {
164 			int shift;
165 			u32  val;
166 			u32  mask;
167 			__be32 *addr;
168 
169 			shift = 32 - desc[i].offset_bits - desc[i].size_bits;
170 			mask = ((1ull << desc[i].size_bits) - 1) << shift;
171 			addr = (__be32 *) buf + desc[i].offset_words;
172 			val = (be32_to_cpup(addr) & mask) >> shift;
173 			value_write(desc[i].struct_offset_bytes,
174 				    desc[i].struct_size_bytes,
175 				    val,
176 				    structure);
177 		} else if (desc[i].size_bits <= 64) {
178 			int shift;
179 			u64  val;
180 			u64  mask;
181 			__be64 *addr;
182 
183 			shift = 64 - desc[i].offset_bits - desc[i].size_bits;
184 			mask = (~0ull >> (64 - desc[i].size_bits)) << shift;
185 			addr = (__be64 *) buf + desc[i].offset_words;
186 			val = (be64_to_cpup(addr) & mask) >> shift;
187 			value_write(desc[i].struct_offset_bytes,
188 				    desc[i].struct_size_bytes,
189 				    val,
190 				    structure);
191 		} else {
192 			if (desc[i].offset_bits % 8 ||
193 			    desc[i].size_bits   % 8) {
194 				pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
195 					desc[i].field_name, desc[i].size_bits);
196 			}
197 
198 			memcpy((char *)structure + desc[i].struct_offset_bytes,
199 			       (char *)buf + desc[i].offset_words * 4 +
200 			       desc[i].offset_bits / 8,
201 			       desc[i].size_bits / 8);
202 		}
203 	}
204 }
205 EXPORT_SYMBOL(ib_unpack);
206