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
39static 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 */
62void 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}
124EXPORT_SYMBOL(ib_pack);
125
126static 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 */
148void 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}
201EXPORT_SYMBOL(ib_unpack);
202