LXR linux/drivers/infiniband/core/packer.c

   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/string.h>
  35
  36#include <rdma/ib_pack.h>
  37
  38static u64 value_read(int offset, int size, void *structure)
  39{
  40        switch (size) {
  41        case 1: return                *(u8  *) (structure + offset);
  42        case 2: return be16_to_cpup((__be16 *) (structure + offset));
  43        case 4: return be32_to_cpup((__be32 *) (structure + offset));
  44        case 8: return be64_to_cpup((__be64 *) (structure + offset));
  45        default:
  46                printk(KERN_WARNING "Field size %d bits not handled\n", size * 8);
  47                return 0;
  48        }
  49}
  50
  51/**
  52 * ib_pack - Pack a structure into a buffer
  53 * @desc:Array of structure field descriptions
  54 * @desc_len:Number of entries in @desc
  55 * @structure:Structure to pack from
  56 * @buf:Buffer to pack into
  57 *
  58 * ib_pack() packs a list of structure fields into a buffer,
  59 * controlled by the array of fields in @desc.
  60 */
  61void ib_pack(const struct ib_field        *desc,
  62             int                           desc_len,
  63             void                         *structure,
  64             void                         *buf)
  65{
  66        int i;
  67
  68        for (i = 0; i < desc_len; ++i) {
  69                if (desc[i].size_bits <= 32) {
  70                        int shift;
  71                        u32 val;
  72                        __be32 mask;
  73                        __be32 *addr;
  74
  75                        shift = 32 - desc[i].offset_bits - desc[i].size_bits;
  76                        if (desc[i].struct_size_bytes)
  77                                val = value_read(desc[i].struct_offset_bytes,
  78                                                 desc[i].struct_size_bytes,
  79                                                 structure) << shift;
  80                        else
  81                                val = 0;
  82
  83                        mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
  84                        addr = (__be32 *) buf + desc[i].offset_words;
  85                        *addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
  86                } else if (desc[i].size_bits <= 64) {
  87                        int shift;
  88                        u64 val;
  89                        __be64 mask;
  90                        __be64 *addr;
  91
  92                        shift = 64 - desc[i].offset_bits - desc[i].size_bits;
  93                        if (desc[i].struct_size_bytes)
  94                                val = value_read(desc[i].struct_offset_bytes,
  95                                                 desc[i].struct_size_bytes,
  96                                                 structure) << shift;
  97                        else
  98                                val = 0;
  99
 100                        mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
 101                        addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
 102                        *addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
 103                } else {
 104                        if (desc[i].offset_bits % 8 ||
 105                            desc[i].size_bits   % 8) {
 106                                printk(KERN_WARNING "Structure field %s of size %d "
 107                                       "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                printk(KERN_WARNING "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                                printk(KERN_WARNING "Structure field %s of size %d "
 191                                       "bits is not byte-aligned\n",
 192                                       desc[i].field_name, desc[i].size_bits);
 193                        }
 194
 195                        memcpy(structure + desc[i].struct_offset_bytes,
 196                               buf + desc[i].offset_words * 4 +
 197                               desc[i].offset_bits / 8,
 198                               desc[i].size_bits / 8);
 199                }
 200        }
 201}
 202EXPORT_SYMBOL(ib_unpack);
 203