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		printk(KERN_WARNING "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				printk(KERN_WARNING "Structure field %s of size %d "
108				       "bits is not byte-aligned\n",
109				       desc[i].field_name, desc[i].size_bits);
110			}
111
112			if (desc[i].struct_size_bytes)
113				memcpy(buf + desc[i].offset_words * 4 +
114				       desc[i].offset_bits / 8,
115				       structure + desc[i].struct_offset_bytes,
116				       desc[i].size_bits / 8);
117			else
118				memset(buf + desc[i].offset_words * 4 +
119				       desc[i].offset_bits / 8,
120				       0,
121				       desc[i].size_bits / 8);
122		}
123	}
124}
125EXPORT_SYMBOL(ib_pack);
126
127static void value_write(int offset, int size, u64 val, void *structure)
128{
129	switch (size * 8) {
130	case 8:  *(    u8 *) (structure + offset) = val; break;
131	case 16: *(__be16 *) (structure + offset) = cpu_to_be16(val); break;
132	case 32: *(__be32 *) (structure + offset) = cpu_to_be32(val); break;
133	case 64: *(__be64 *) (structure + offset) = cpu_to_be64(val); break;
134	default:
135		printk(KERN_WARNING "Field size %d bits not handled\n", size * 8);
136	}
137}
138
139/**
140 * ib_unpack - Unpack a buffer into a structure
141 * @desc:Array of structure field descriptions
142 * @desc_len:Number of entries in @desc
143 * @buf:Buffer to unpack from
144 * @structure:Structure to unpack into
145 *
146 * ib_pack() unpacks a list of structure fields from a buffer,
147 * controlled by the array of fields in @desc.
148 */
149void ib_unpack(const struct ib_field        *desc,
150	       int                           desc_len,
151	       void                         *buf,
152	       void                         *structure)
153{
154	int i;
155
156	for (i = 0; i < desc_len; ++i) {
157		if (!desc[i].struct_size_bytes)
158			continue;
159
160		if (desc[i].size_bits <= 32) {
161			int shift;
162			u32  val;
163			u32  mask;
164			__be32 *addr;
165
166			shift = 32 - desc[i].offset_bits - desc[i].size_bits;
167			mask = ((1ull << desc[i].size_bits) - 1) << shift;
168			addr = (__be32 *) buf + desc[i].offset_words;
169			val = (be32_to_cpup(addr) & mask) >> shift;
170			value_write(desc[i].struct_offset_bytes,
171				    desc[i].struct_size_bytes,
172				    val,
173				    structure);
174		} else if (desc[i].size_bits <= 64) {
175			int shift;
176			u64  val;
177			u64  mask;
178			__be64 *addr;
179
180			shift = 64 - desc[i].offset_bits - desc[i].size_bits;
181			mask = (~0ull >> (64 - desc[i].size_bits)) << shift;
182			addr = (__be64 *) buf + desc[i].offset_words;
183			val = (be64_to_cpup(addr) & mask) >> shift;
184			value_write(desc[i].struct_offset_bytes,
185				    desc[i].struct_size_bytes,
186				    val,
187				    structure);
188		} else {
189			if (desc[i].offset_bits % 8 ||
190			    desc[i].size_bits   % 8) {
191				printk(KERN_WARNING "Structure field %s of size %d "
192				       "bits is not byte-aligned\n",
193				       desc[i].field_name, desc[i].size_bits);
194			}
195
196			memcpy(structure + desc[i].struct_offset_bytes,
197			       buf + desc[i].offset_words * 4 +
198			       desc[i].offset_bits / 8,
199			       desc[i].size_bits / 8);
200		}
201	}
202}
203EXPORT_SYMBOL(ib_unpack);
204