drivers/infiniband/core/packer.c

   1 /*
   2  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  *
  32  * $Id: packer.c 1349 2004-12-16 21:09:43Z roland $
  33  */
  34
  35 #include <ib_pack.h>
  36
  37 static u64 value_read(int offset, int size, void *structure)
  38 {
  39         switch (size) {
  40         case 1: return                *(u8  *) (structure + offset);
  41         case 2: return be16_to_cpup((__be16 *) (structure + offset));
  42         case 4: return be32_to_cpup((__be32 *) (structure + offset));
  43         case 8: return be64_to_cpup((__be64 *) (structure + offset));
  44         default:
  45                 printk(KERN_WARNING "Field size %d bits not handled\n", size * 8);
  46                 return 0;
  47         }
  48 }
  49
  50 /**
  51  * ib_pack - Pack a structure into a buffer
  52  * @desc:Array of structure field descriptions
  53  * @desc_len:Number of entries in @desc
  54  * @structure:Structure to pack from
  55  * @buf:Buffer to pack into
  56  *
  57  * ib_pack() packs a list of structure fields into a buffer,
  58  * controlled by the array of fields in @desc.
  59  */
  60 void ib_pack(const struct ib_field        *desc,
  61              int                           desc_len,
  62              void                         *structure,
  63              void                         *buf)
  64 {
  65         int i;
  66
  67         for (i = 0; i < desc_len; ++i) {
  68                 if (desc[i].size_bits <= 32) {
  69                         int shift;
  70                         u32 val;
  71                         __be32 mask;
  72                         __be32 *addr;
  73
  74                         shift = 32 - desc[i].offset_bits - desc[i].size_bits;
  75                         if (desc[i].struct_size_bytes)
  76                                 val = value_read(desc[i].struct_offset_bytes,
  77                                                  desc[i].struct_size_bytes,
  78                                                  structure) << shift;
  79                         else
  80                                 val = 0;
  81
  82                         mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
  83                         addr = (__be32 *) buf + desc[i].offset_words;
  84                         *addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
  85                 } else if (desc[i].size_bits <= 64) {
  86                         int shift;
  87                         u64 val;
  88                         __be64 mask;
  89                         __be64 *addr;
  90
  91                         shift = 64 - desc[i].offset_bits - desc[i].size_bits;
  92                         if (desc[i].struct_size_bytes)
  93                                 val = value_read(desc[i].struct_offset_bytes,
  94                                                  desc[i].struct_size_bytes,
  95                                                  structure) << shift;
  96                         else
  97                                 val = 0;
  98
  99                         mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
 100                         addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
 101                         *addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
 102                 } else {
 103                         if (desc[i].offset_bits % 8 ||
 104                             desc[i].size_bits   % 8) {
 105                                 printk(KERN_WARNING "Structure field %s of size %d "
 106                                        "bits is not byte-aligned\n",
 107                                        desc[i].field_name, desc[i].size_bits);
 108                         }
 109
 110                         if (desc[i].struct_size_bytes)
 111                                 memcpy(buf + desc[i].offset_words * 4 +
 112                                        desc[i].offset_bits / 8,
 113                                        structure + desc[i].struct_offset_bytes,
 114                                        desc[i].size_bits / 8);
 115                         else
 116                                 memset(buf + desc[i].offset_words * 4 +
 117                                        desc[i].offset_bits / 8,
 118                                        0,
 119                                        desc[i].size_bits / 8);
 120                 }
 121         }
 122 }
 123 EXPORT_SYMBOL(ib_pack);
 124
 125 static void value_write(int offset, int size, u64 val, void *structure)
 126 {
 127         switch (size * 8) {
 128         case 8:  *(    u8 *) (structure + offset) = val; break;
 129         case 16: *(__be16 *) (structure + offset) = cpu_to_be16(val); break;
 130         case 32: *(__be32 *) (structure + offset) = cpu_to_be32(val); break;
 131         case 64: *(__be64 *) (structure + offset) = cpu_to_be64(val); break;
 132         default:
 133                 printk(KERN_WARNING "Field size %d bits not handled\n", size * 8);
 134         }
 135 }
 136
 137 /**
 138  * ib_unpack - Unpack a buffer into a structure
 139  * @desc:Array of structure field descriptions
 140  * @desc_len:Number of entries in @desc
 141  * @buf:Buffer to unpack from
 142  * @structure:Structure to unpack into
 143  *
 144  * ib_pack() unpacks a list of structure fields from a buffer,
 145  * controlled by the array of fields in @desc.
 146  */
 147 void ib_unpack(const struct ib_field        *desc,
 148                int                           desc_len,
 149                void                         *buf,
 150                void                         *structure)
 151 {
 152         int i;
 153
 154         for (i = 0; i < desc_len; ++i) {
 155                 if (!desc[i].struct_size_bytes)
 156                         continue;
 157
 158                 if (desc[i].size_bits <= 32) {
 159                         int shift;
 160                         u32  val;
 161                         u32  mask;
 162                         __be32 *addr;
 163
 164                         shift = 32 - desc[i].offset_bits - desc[i].size_bits;
 165                         mask = ((1ull << desc[i].size_bits) - 1) << shift;
 166                         addr = (__be32 *) buf + desc[i].offset_words;
 167                         val = (be32_to_cpup(addr) & mask) >> shift;
 168                         value_write(desc[i].struct_offset_bytes,
 169                                     desc[i].struct_size_bytes,
 170                                     val,
 171                                     structure);
 172                 } else if (desc[i].size_bits <= 64) {
 173                         int shift;
 174                         u64  val;
 175                         u64  mask;
 176                         __be64 *addr;
 177
 178                         shift = 64 - desc[i].offset_bits - desc[i].size_bits;
 179                         mask = (~0ull >> (64 - desc[i].size_bits)) << shift;
 180                         addr = (__be64 *) buf + desc[i].offset_words;
 181                         val = (be64_to_cpup(addr) & mask) >> shift;
 182                         value_write(desc[i].struct_offset_bytes,
 183                                     desc[i].struct_size_bytes,
 184                                     val,
 185                                     structure);
 186                 } else {
 187                         if (desc[i].offset_bits % 8 ||
 188                             desc[i].size_bits   % 8) {
 189                                 printk(KERN_WARNING "Structure field %s of size %d "
 190                                        "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 }
 201 EXPORT_SYMBOL(ib_unpack);