infiniband/core/packer.c

0001 /*
0002  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
0003  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
0004  *
0005  * This software is available to you under a choice of one of two
0006  * licenses.  You may choose to be licensed under the terms of the GNU
0007  * General Public License (GPL) Version 2, available from the file
0008  * COPYING in the main directory of this source tree, or the
0009  * OpenIB.org BSD license below:
0010  *
0011  *     Redistribution and use in source and binary forms, with or
0012  *     without modification, are permitted provided that the following
0013  *     conditions are met:
0014  *
0015  *      - Redistributions of source code must retain the above
0016  *        copyright notice, this list of conditions and the following
0017  *        disclaimer.
0018  *
0019  *      - Redistributions in binary form must reproduce the above
0020  *        copyright notice, this list of conditions and the following
0021  *        disclaimer in the documentation and/or other materials
0022  *        provided with the distribution.
0023  *
0024  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
0025  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
0026  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
0027  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
0028  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
0029  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
0030  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
0031  * SOFTWARE.
0032  */
0033
0034 #include <linux/export.h>
0035 #include <linux/string.h>
0036
0037 #include <rdma/ib_pack.h>
0038
0039 static u64 value_read(int offset, int size, void *structure)
0040 {
0041     switch (size) {
0042     case 1: return                *(u8  *) (structure + offset);
0043     case 2: return be16_to_cpup((__be16 *) (structure + offset));
0044     case 4: return be32_to_cpup((__be32 *) (structure + offset));
0045     case 8: return be64_to_cpup((__be64 *) (structure + offset));
0046     default:
0047         pr_warn("Field size %d bits not handled\n", size * 8);
0048         return 0;
0049     }
0050 }
0051
0052 /**
0053  * ib_pack - Pack a structure into a buffer
0054  * @desc:Array of structure field descriptions
0055  * @desc_len:Number of entries in @desc
0056  * @structure:Structure to pack from
0057  * @buf:Buffer to pack into
0058  *
0059  * ib_pack() packs a list of structure fields into a buffer,
0060  * controlled by the array of fields in @desc.
0061  */
0062 void ib_pack(const struct ib_field        *desc,
0063          int                           desc_len,
0064          void                         *structure,
0065          void                         *buf)
0066 {
0067     int i;
0068
0069     for (i = 0; i < desc_len; ++i) {
0070         if (desc[i].size_bits <= 32) {
0071             int shift;
0072             u32 val;
0073             __be32 mask;
0074             __be32 *addr;
0075
0076             shift = 32 - desc[i].offset_bits - desc[i].size_bits;
0077             if (desc[i].struct_size_bytes)
0078                 val = value_read(desc[i].struct_offset_bytes,
0079                          desc[i].struct_size_bytes,
0080                          structure) << shift;
0081             else
0082                 val = 0;
0083
0084             mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
0085             addr = (__be32 *) buf + desc[i].offset_words;
0086             *addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
0087         } else if (desc[i].size_bits <= 64) {
0088             int shift;
0089             u64 val;
0090             __be64 mask;
0091             __be64 *addr;
0092
0093             shift = 64 - desc[i].offset_bits - desc[i].size_bits;
0094             if (desc[i].struct_size_bytes)
0095                 val = value_read(desc[i].struct_offset_bytes,
0096                          desc[i].struct_size_bytes,
0097                          structure) << shift;
0098             else
0099                 val = 0;
0100
0101             mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
0102             addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
0103             *addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
0104         } else {
0105             if (desc[i].offset_bits % 8 ||
0106                 desc[i].size_bits   % 8) {
0107                 pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
0108                     desc[i].field_name, desc[i].size_bits);
0109             }
0110
0111             if (desc[i].struct_size_bytes)
0112                 memcpy(buf + desc[i].offset_words * 4 +
0113                        desc[i].offset_bits / 8,
0114                        structure + desc[i].struct_offset_bytes,
0115                        desc[i].size_bits / 8);
0116             else
0117                 memset(buf + desc[i].offset_words * 4 +
0118                        desc[i].offset_bits / 8,
0119                        0,
0120                        desc[i].size_bits / 8);
0121         }
0122     }
0123 }
0124 EXPORT_SYMBOL(ib_pack);
0125
0126 static void value_write(int offset, int size, u64 val, void *structure)
0127 {
0128     switch (size * 8) {
0129     case 8:  *(    u8 *) (structure + offset) = val; break;
0130     case 16: *(__be16 *) (structure + offset) = cpu_to_be16(val); break;
0131     case 32: *(__be32 *) (structure + offset) = cpu_to_be32(val); break;
0132     case 64: *(__be64 *) (structure + offset) = cpu_to_be64(val); break;
0133     default:
0134         pr_warn("Field size %d bits not handled\n", size * 8);
0135     }
0136 }
0137
0138 /**
0139  * ib_unpack - Unpack a buffer into a structure
0140  * @desc:Array of structure field descriptions
0141  * @desc_len:Number of entries in @desc
0142  * @buf:Buffer to unpack from
0143  * @structure:Structure to unpack into
0144  *
0145  * ib_pack() unpacks a list of structure fields from a buffer,
0146  * controlled by the array of fields in @desc.
0147  */
0148 void ib_unpack(const struct ib_field        *desc,
0149            int                           desc_len,
0150            void                         *buf,
0151            void                         *structure)
0152 {
0153     int i;
0154
0155     for (i = 0; i < desc_len; ++i) {
0156         if (!desc[i].struct_size_bytes)
0157             continue;
0158
0159         if (desc[i].size_bits <= 32) {
0160             int shift;
0161             u32  val;
0162             u32  mask;
0163             __be32 *addr;
0164
0165             shift = 32 - desc[i].offset_bits - desc[i].size_bits;
0166             mask = ((1ull << desc[i].size_bits) - 1) << shift;
0167             addr = (__be32 *) buf + desc[i].offset_words;
0168             val = (be32_to_cpup(addr) & mask) >> shift;
0169             value_write(desc[i].struct_offset_bytes,
0170                     desc[i].struct_size_bytes,
0171                     val,
0172                     structure);
0173         } else if (desc[i].size_bits <= 64) {
0174             int shift;
0175             u64  val;
0176             u64  mask;
0177             __be64 *addr;
0178
0179             shift = 64 - desc[i].offset_bits - desc[i].size_bits;
0180             mask = (~0ull >> (64 - desc[i].size_bits)) << shift;
0181             addr = (__be64 *) buf + desc[i].offset_words;
0182             val = (be64_to_cpup(addr) & mask) >> shift;
0183             value_write(desc[i].struct_offset_bytes,
0184                     desc[i].struct_size_bytes,
0185                     val,
0186                     structure);
0187         } else {
0188             if (desc[i].offset_bits % 8 ||
0189                 desc[i].size_bits   % 8) {
0190                 pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
0191                     desc[i].field_name, desc[i].size_bits);
0192             }
0193
0194             memcpy(structure + desc[i].struct_offset_bytes,
0195                    buf + desc[i].offset_words * 4 +
0196                    desc[i].offset_bits / 8,
0197                    desc[i].size_bits / 8);
0198         }
0199     }
0200 }
0201 EXPORT_SYMBOL(ib_unpack);