kernel/drivers/block/rsxx/config.c

   1 /*
   2 * Filename: config.c
   3 *
   4 *
   5 * Authors: Joshua Morris <josh.h.morris@us.ibm.com>
   6 *       Philip Kelleher <pjk1939@linux.vnet.ibm.com>
   7 *
   8 * (C) Copyright 2013 IBM Corporation
   9 *
  10 * This program is free software; you can redistribute it and/or
  11 * modify it under the terms of the GNU General Public License as
  12 * published by the Free Software Foundation; either version 2 of the
  13 * License, or (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful, but
  16 * WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18 * General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software Foundation,
  22 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23 */
  24
  25 #include <linux/types.h>
  26 #include <linux/crc32.h>
  27 #include <linux/swab.h>
  28
  29 #include "rsxx_priv.h"
  30 #include "rsxx_cfg.h"
  31
  32 static void initialize_config(struct rsxx_card_cfg *cfg)
  33 {
  34         cfg->hdr.version = RSXX_CFG_VERSION;
  35
  36         cfg->data.block_size        = RSXX_HW_BLK_SIZE;
  37         cfg->data.stripe_size       = RSXX_HW_BLK_SIZE;
  38         cfg->data.vendor_id         = RSXX_VENDOR_ID_IBM;
  39         cfg->data.cache_order       = (-1);
  40         cfg->data.intr_coal.mode    = RSXX_INTR_COAL_DISABLED;
  41         cfg->data.intr_coal.count   = 0;
  42         cfg->data.intr_coal.latency = 0;
  43 }
  44
  45 static u32 config_data_crc32(struct rsxx_card_cfg *cfg)
  46 {
  47         /*
  48          * Return the compliment of the CRC to ensure compatibility
  49          * (i.e. this is how early rsxx drivers did it.)
  50          */
  51
  52         return ~crc32(~0, &cfg->data, sizeof(cfg->data));
  53 }
  54
  55
  56 /*----------------- Config Byte Swap Functions -------------------*/
  57 static void config_hdr_be_to_cpu(struct card_cfg_hdr *hdr)
  58 {
  59         hdr->version = be32_to_cpu((__force __be32) hdr->version);
  60         hdr->crc     = be32_to_cpu((__force __be32) hdr->crc);
  61 }
  62
  63 static void config_hdr_cpu_to_be(struct card_cfg_hdr *hdr)
  64 {
  65         hdr->version = (__force u32) cpu_to_be32(hdr->version);
  66         hdr->crc     = (__force u32) cpu_to_be32(hdr->crc);
  67 }
  68
  69 static void config_data_swab(struct rsxx_card_cfg *cfg)
  70 {
  71         u32 *data = (u32 *) &cfg->data;
  72         int i;
  73
  74         for (i = 0; i < (sizeof(cfg->data) / 4); i++)
  75                 data[i] = swab32(data[i]);
  76 }
  77
  78 static void config_data_le_to_cpu(struct rsxx_card_cfg *cfg)
  79 {
  80         u32 *data = (u32 *) &cfg->data;
  81         int i;
  82
  83         for (i = 0; i < (sizeof(cfg->data) / 4); i++)
  84                 data[i] = le32_to_cpu((__force __le32) data[i]);
  85 }
  86
  87 static void config_data_cpu_to_le(struct rsxx_card_cfg *cfg)
  88 {
  89         u32 *data = (u32 *) &cfg->data;
  90         int i;
  91
  92         for (i = 0; i < (sizeof(cfg->data) / 4); i++)
  93                 data[i] = (__force u32) cpu_to_le32(data[i]);
  94 }
  95
  96
  97 /*----------------- Config Operations ------------------*/
  98 static int rsxx_save_config(struct rsxx_cardinfo *card)
  99 {
 100         struct rsxx_card_cfg cfg;
 101         int st;
 102
 103         memcpy(&cfg, &card->config, sizeof(cfg));
 104
 105         if (unlikely(cfg.hdr.version != RSXX_CFG_VERSION)) {
 106                 dev_err(CARD_TO_DEV(card),
 107                         "Cannot save config with invalid version %d\n",
 108                         cfg.hdr.version);
 109                 return -EINVAL;
 110         }
 111
 112         /* Convert data to little endian for the CRC calculation. */
 113         config_data_cpu_to_le(&cfg);
 114
 115         cfg.hdr.crc = config_data_crc32(&cfg);
 116
 117         /*
 118          * Swap the data from little endian to big endian so it can be
 119          * stored.
 120          */
 121         config_data_swab(&cfg);
 122         config_hdr_cpu_to_be(&cfg.hdr);
 123
 124         st = rsxx_creg_write(card, CREG_ADD_CONFIG, sizeof(cfg), &cfg, 1);
 125         if (st)
 126                 return st;
 127
 128         return 0;
 129 }
 130
 131 int rsxx_load_config(struct rsxx_cardinfo *card)
 132 {
 133         int st;
 134         u32 crc;
 135
 136         st = rsxx_creg_read(card, CREG_ADD_CONFIG, sizeof(card->config),
 137                                 &card->config, 1);
 138         if (st) {
 139                 dev_err(CARD_TO_DEV(card),
 140                         "Failed reading card config.\n");
 141                 return st;
 142         }
 143
 144         config_hdr_be_to_cpu(&card->config.hdr);
 145
 146         if (card->config.hdr.version == RSXX_CFG_VERSION) {
 147                 /*
 148                  * We calculate the CRC with the data in little endian, because
 149                  * early drivers did not take big endian CPUs into account.
 150                  * The data is always stored in big endian, so we need to byte
 151                  * swap it before calculating the CRC.
 152                  */
 153
 154                 config_data_swab(&card->config);
 155
 156                 /* Check the CRC */
 157                 crc = config_data_crc32(&card->config);
 158                 if (crc != card->config.hdr.crc) {
 159                         dev_err(CARD_TO_DEV(card),
 160                                 "Config corruption detected!\n");
 161                         dev_info(CARD_TO_DEV(card),
 162                                 "CRC (sb x%08x is x%08x)\n",
 163                                 card->config.hdr.crc, crc);
 164                         return -EIO;
 165                 }
 166
 167                 /* Convert the data to CPU byteorder */
 168                 config_data_le_to_cpu(&card->config);
 169
 170         } else if (card->config.hdr.version != 0) {
 171                 dev_err(CARD_TO_DEV(card),
 172                         "Invalid config version %d.\n",
 173                         card->config.hdr.version);
 174                 /*
 175                  * Config version changes require special handling from the
 176                  * user
 177                  */
 178                 return -EINVAL;
 179         } else {
 180                 dev_info(CARD_TO_DEV(card),
 181                         "Initializing card configuration.\n");
 182                 initialize_config(&card->config);
 183                 st = rsxx_save_config(card);
 184                 if (st)
 185                         return st;
 186         }
 187
 188         card->config_valid = 1;
 189
 190         dev_dbg(CARD_TO_DEV(card), "version:     x%08x\n",
 191                 card->config.hdr.version);
 192         dev_dbg(CARD_TO_DEV(card), "crc:         x%08x\n",
 193                 card->config.hdr.crc);
 194         dev_dbg(CARD_TO_DEV(card), "block_size:  x%08x\n",
 195                 card->config.data.block_size);
 196         dev_dbg(CARD_TO_DEV(card), "stripe_size: x%08x\n",
 197                 card->config.data.stripe_size);
 198         dev_dbg(CARD_TO_DEV(card), "vendor_id:   x%08x\n",
 199                 card->config.data.vendor_id);
 200         dev_dbg(CARD_TO_DEV(card), "cache_order: x%08x\n",
 201                 card->config.data.cache_order);
 202         dev_dbg(CARD_TO_DEV(card), "mode:        x%08x\n",
 203                 card->config.data.intr_coal.mode);
 204         dev_dbg(CARD_TO_DEV(card), "count:       x%08x\n",
 205                 card->config.data.intr_coal.count);
 206         dev_dbg(CARD_TO_DEV(card), "latency:     x%08x\n",
 207                  card->config.data.intr_coal.latency);
 208
 209         return 0;
 210 }
 211