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/export.h>
  35 #include <linux/string.h>
  36
  37 #include <rdma/ib_pack.h>
  38
  39 static 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                 pr_warn("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  */
  62 void 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                                 pr_warn("Structure field %s of size %d 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 }
 124 EXPORT_SYMBOL(ib_pack);
 125
 126 static 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                 pr_warn("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  */
 148 void 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                                 pr_warn("Structure field %s of size %d 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);