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  * $Id: packer.c 1349 2004-12-16 21:09:43Z roland $
  34  */
  35
  36 #include <linux/string.h>
  37
  38 #include <rdma/ib_pack.h>
  39
  40 static u64 value_read(int offset, int size, void *structure)
  41 {
  42         switch (size) {
  43         case 1: return                *(u8  *) (structure + offset);
  44         case 2: return be16_to_cpup((__be16 *) (structure + offset));
  45         case 4: return be32_to_cpup((__be32 *) (structure + offset));
  46         case 8: return be64_to_cpup((__be64 *) (structure + offset));
  47         default:
  48                 printk(KERN_WARNING "Field size %d bits not handled\n", size * 8);
  49                 return 0;
  50         }
  51 }
  52
  53 /**
  54  * ib_pack - Pack a structure into a buffer
  55  * @desc:Array of structure field descriptions
  56  * @desc_len:Number of entries in @desc
  57  * @structure:Structure to pack from
  58  * @buf:Buffer to pack into
  59  *
  60  * ib_pack() packs a list of structure fields into a buffer,
  61  * controlled by the array of fields in @desc.
  62  */
  63 void ib_pack(const struct ib_field        *desc,
  64              int                           desc_len,
  65              void                         *structure,
  66              void                         *buf)
  67 {
  68         int i;
  69
  70         for (i = 0; i < desc_len; ++i) {
  71                 if (desc[i].size_bits <= 32) {
  72                         int shift;
  73                         u32 val;
  74                         __be32 mask;
  75                         __be32 *addr;
  76
  77                         shift = 32 - desc[i].offset_bits - desc[i].size_bits;
  78                         if (desc[i].struct_size_bytes)
  79                                 val = value_read(desc[i].struct_offset_bytes,
  80                                                  desc[i].struct_size_bytes,
  81                                                  structure) << shift;
  82                         else
  83                                 val = 0;
  84
  85                         mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
  86                         addr = (__be32 *) buf + desc[i].offset_words;
  87                         *addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
  88                 } else if (desc[i].size_bits <= 64) {
  89                         int shift;
  90                         u64 val;
  91                         __be64 mask;
  92                         __be64 *addr;
  93
  94                         shift = 64 - desc[i].offset_bits - desc[i].size_bits;
  95                         if (desc[i].struct_size_bytes)
  96                                 val = value_read(desc[i].struct_offset_bytes,
  97                                                  desc[i].struct_size_bytes,
  98                                                  structure) << shift;
  99                         else
 100                                 val = 0;
 101
 102                         mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
 103                         addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
 104                         *addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
 105                 } else {
 106                         if (desc[i].offset_bits % 8 ||
 107                             desc[i].size_bits   % 8) {
 108                                 printk(KERN_WARNING "Structure field %s of size %d "
 109                                        "bits is not byte-aligned\n",
 110                                        desc[i].field_name, desc[i].size_bits);
 111                         }
 112
 113                         if (desc[i].struct_size_bytes)
 114                                 memcpy(buf + desc[i].offset_words * 4 +
 115                                        desc[i].offset_bits / 8,
 116                                        structure + desc[i].struct_offset_bytes,
 117                                        desc[i].size_bits / 8);
 118                         else
 119                                 memset(buf + desc[i].offset_words * 4 +
 120                                        desc[i].offset_bits / 8,
 121                                        0,
 122                                        desc[i].size_bits / 8);
 123                 }
 124         }
 125 }
 126 EXPORT_SYMBOL(ib_pack);
 127
 128 static void value_write(int offset, int size, u64 val, void *structure)
 129 {
 130         switch (size * 8) {
 131         case 8:  *(    u8 *) (structure + offset) = val; break;
 132         case 16: *(__be16 *) (structure + offset) = cpu_to_be16(val); break;
 133         case 32: *(__be32 *) (structure + offset) = cpu_to_be32(val); break;
 134         case 64: *(__be64 *) (structure + offset) = cpu_to_be64(val); break;
 135         default:
 136                 printk(KERN_WARNING "Field size %d bits not handled\n", size * 8);
 137         }
 138 }
 139
 140 /**
 141  * ib_unpack - Unpack a buffer into a structure
 142  * @desc:Array of structure field descriptions
 143  * @desc_len:Number of entries in @desc
 144  * @buf:Buffer to unpack from
 145  * @structure:Structure to unpack into
 146  *
 147  * ib_pack() unpacks a list of structure fields from a buffer,
 148  * controlled by the array of fields in @desc.
 149  */
 150 void ib_unpack(const struct ib_field        *desc,
 151                int                           desc_len,
 152                void                         *buf,
 153                void                         *structure)
 154 {
 155         int i;
 156
 157         for (i = 0; i < desc_len; ++i) {
 158                 if (!desc[i].struct_size_bytes)
 159                         continue;
 160
 161                 if (desc[i].size_bits <= 32) {
 162                         int shift;
 163                         u32  val;
 164                         u32  mask;
 165                         __be32 *addr;
 166
 167                         shift = 32 - desc[i].offset_bits - desc[i].size_bits;
 168                         mask = ((1ull << desc[i].size_bits) - 1) << shift;
 169                         addr = (__be32 *) buf + desc[i].offset_words;
 170                         val = (be32_to_cpup(addr) & mask) >> shift;
 171                         value_write(desc[i].struct_offset_bytes,
 172                                     desc[i].struct_size_bytes,
 173                                     val,
 174                                     structure);
 175                 } else if (desc[i].size_bits <= 64) {
 176                         int shift;
 177                         u64  val;
 178                         u64  mask;
 179                         __be64 *addr;
 180
 181                         shift = 64 - desc[i].offset_bits - desc[i].size_bits;
 182                         mask = (~0ull >> (64 - desc[i].size_bits)) << shift;
 183                         addr = (__be64 *) buf + desc[i].offset_words;
 184                         val = (be64_to_cpup(addr) & mask) >> shift;
 185                         value_write(desc[i].struct_offset_bytes,
 186                                     desc[i].struct_size_bytes,
 187                                     val,
 188                                     structure);
 189                 } else {
 190                         if (desc[i].offset_bits % 8 ||
 191                             desc[i].size_bits   % 8) {
 192                                 printk(KERN_WARNING "Structure field %s of size %d "
 193                                        "bits is not byte-aligned\n",
 194                                        desc[i].field_name, desc[i].size_bits);
 195                         }
 196
 197                         memcpy(structure + desc[i].struct_offset_bytes,
 198                                buf + desc[i].offset_words * 4 +
 199                                desc[i].offset_bits / 8,
 200                                desc[i].size_bits / 8);
 201                 }
 202         }
 203 }
 204 EXPORT_SYMBOL(ib_unpack);