kernel/drivers/scsi/device_handler/scsi_dh_hp_sw.c

   1 /*
   2  * Basic HP/COMPAQ MSA 1000 support. This is only needed if your HW cannot be
   3  * upgraded.
   4  *
   5  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   6  * Copyright (C) 2006 Mike Christie
   7  * Copyright (C) 2008 Hannes Reinecke <hare@suse.de>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2, or (at your option)
  12  * any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; see the file COPYING.  If not, write to
  21  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #include <linux/slab.h>
  25 #include <linux/module.h>
  26 #include <scsi/scsi.h>
  27 #include <scsi/scsi_dbg.h>
  28 #include <scsi/scsi_eh.h>
  29 #include <scsi/scsi_dh.h>
  30
  31 #define HP_SW_NAME                      "hp_sw"
  32
  33 #define HP_SW_TIMEOUT                   (60 * HZ)
  34 #define HP_SW_RETRIES                   3
  35
  36 #define HP_SW_PATH_UNINITIALIZED        -1
  37 #define HP_SW_PATH_ACTIVE               0
  38 #define HP_SW_PATH_PASSIVE              1
  39
  40 struct hp_sw_dh_data {
  41         unsigned char sense[SCSI_SENSE_BUFFERSIZE];
  42         int path_state;
  43         int retries;
  44         int retry_cnt;
  45         struct scsi_device *sdev;
  46         activate_complete       callback_fn;
  47         void                    *callback_data;
  48 };
  49
  50 static int hp_sw_start_stop(struct hp_sw_dh_data *);
  51
  52 /*
  53  * tur_done - Handle TEST UNIT READY return status
  54  * @sdev: sdev the command has been sent to
  55  * @errors: blk error code
  56  *
  57  * Returns SCSI_DH_DEV_OFFLINED if the sdev is on the passive path
  58  */
  59 static int tur_done(struct scsi_device *sdev, unsigned char *sense)
  60 {
  61         struct scsi_sense_hdr sshdr;
  62         int ret;
  63
  64         ret = scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
  65         if (!ret) {
  66                 sdev_printk(KERN_WARNING, sdev,
  67                             "%s: sending tur failed, no sense available\n",
  68                             HP_SW_NAME);
  69                 ret = SCSI_DH_IO;
  70                 goto done;
  71         }
  72         switch (sshdr.sense_key) {
  73         case UNIT_ATTENTION:
  74                 ret = SCSI_DH_IMM_RETRY;
  75                 break;
  76         case NOT_READY:
  77                 if ((sshdr.asc == 0x04) && (sshdr.ascq == 2)) {
  78                         /*
  79                          * LUN not ready - Initialization command required
  80                          *
  81                          * This is the passive path
  82                          */
  83                         ret = SCSI_DH_DEV_OFFLINED;
  84                         break;
  85                 }
  86                 /* Fallthrough */
  87         default:
  88                 sdev_printk(KERN_WARNING, sdev,
  89                            "%s: sending tur failed, sense %x/%x/%x\n",
  90                            HP_SW_NAME, sshdr.sense_key, sshdr.asc,
  91                            sshdr.ascq);
  92                 break;
  93         }
  94
  95 done:
  96         return ret;
  97 }
  98
  99 /*
 100  * hp_sw_tur - Send TEST UNIT READY
 101  * @sdev: sdev command should be sent to
 102  *
 103  * Use the TEST UNIT READY command to determine
 104  * the path state.
 105  */
 106 static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
 107 {
 108         struct request *req;
 109         int ret;
 110
 111 retry:
 112         req = blk_get_request(sdev->request_queue, WRITE, GFP_NOIO);
 113         if (IS_ERR(req))
 114                 return SCSI_DH_RES_TEMP_UNAVAIL;
 115
 116         blk_rq_set_block_pc(req);
 117         req->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 118                           REQ_FAILFAST_DRIVER;
 119         req->cmd_len = COMMAND_SIZE(TEST_UNIT_READY);
 120         req->cmd[0] = TEST_UNIT_READY;
 121         req->timeout = HP_SW_TIMEOUT;
 122         req->sense = h->sense;
 123         memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
 124         req->sense_len = 0;
 125
 126         ret = blk_execute_rq(req->q, NULL, req, 1);
 127         if (ret == -EIO) {
 128                 if (req->sense_len > 0) {
 129                         ret = tur_done(sdev, h->sense);
 130                 } else {
 131                         sdev_printk(KERN_WARNING, sdev,
 132                                     "%s: sending tur failed with %x\n",
 133                                     HP_SW_NAME, req->errors);
 134                         ret = SCSI_DH_IO;
 135                 }
 136         } else {
 137                 h->path_state = HP_SW_PATH_ACTIVE;
 138                 ret = SCSI_DH_OK;
 139         }
 140         if (ret == SCSI_DH_IMM_RETRY) {
 141                 blk_put_request(req);
 142                 goto retry;
 143         }
 144         if (ret == SCSI_DH_DEV_OFFLINED) {
 145                 h->path_state = HP_SW_PATH_PASSIVE;
 146                 ret = SCSI_DH_OK;
 147         }
 148
 149         blk_put_request(req);
 150
 151         return ret;
 152 }
 153
 154 /*
 155  * start_done - Handle START STOP UNIT return status
 156  * @sdev: sdev the command has been sent to
 157  * @errors: blk error code
 158  */
 159 static int start_done(struct scsi_device *sdev, unsigned char *sense)
 160 {
 161         struct scsi_sense_hdr sshdr;
 162         int rc;
 163
 164         rc = scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr);
 165         if (!rc) {
 166                 sdev_printk(KERN_WARNING, sdev,
 167                             "%s: sending start_stop_unit failed, "
 168                             "no sense available\n",
 169                             HP_SW_NAME);
 170                 return SCSI_DH_IO;
 171         }
 172         switch (sshdr.sense_key) {
 173         case NOT_READY:
 174                 if ((sshdr.asc == 0x04) && (sshdr.ascq == 3)) {
 175                         /*
 176                          * LUN not ready - manual intervention required
 177                          *
 178                          * Switch-over in progress, retry.
 179                          */
 180                         rc = SCSI_DH_RETRY;
 181                         break;
 182                 }
 183                 /* fall through */
 184         default:
 185                 sdev_printk(KERN_WARNING, sdev,
 186                            "%s: sending start_stop_unit failed, sense %x/%x/%x\n",
 187                            HP_SW_NAME, sshdr.sense_key, sshdr.asc,
 188                            sshdr.ascq);
 189                 rc = SCSI_DH_IO;
 190         }
 191
 192         return rc;
 193 }
 194
 195 static void start_stop_endio(struct request *req, int error)
 196 {
 197         struct hp_sw_dh_data *h = req->end_io_data;
 198         unsigned err = SCSI_DH_OK;
 199
 200         if (error || host_byte(req->errors) != DID_OK ||
 201                         msg_byte(req->errors) != COMMAND_COMPLETE) {
 202                 sdev_printk(KERN_WARNING, h->sdev,
 203                             "%s: sending start_stop_unit failed with %x\n",
 204                             HP_SW_NAME, req->errors);
 205                 err = SCSI_DH_IO;
 206                 goto done;
 207         }
 208
 209         if (req->sense_len > 0) {
 210                 err = start_done(h->sdev, h->sense);
 211                 if (err == SCSI_DH_RETRY) {
 212                         err = SCSI_DH_IO;
 213                         if (--h->retry_cnt) {
 214                                 blk_put_request(req);
 215                                 err = hp_sw_start_stop(h);
 216                                 if (err == SCSI_DH_OK)
 217                                         return;
 218                         }
 219                 }
 220         }
 221 done:
 222         req->end_io_data = NULL;
 223         __blk_put_request(req->q, req);
 224         if (h->callback_fn) {
 225                 h->callback_fn(h->callback_data, err);
 226                 h->callback_fn = h->callback_data = NULL;
 227         }
 228         return;
 229
 230 }
 231
 232 /*
 233  * hp_sw_start_stop - Send START STOP UNIT command
 234  * @sdev: sdev command should be sent to
 235  *
 236  * Sending START STOP UNIT activates the SP.
 237  */
 238 static int hp_sw_start_stop(struct hp_sw_dh_data *h)
 239 {
 240         struct request *req;
 241
 242         req = blk_get_request(h->sdev->request_queue, WRITE, GFP_ATOMIC);
 243         if (IS_ERR(req))
 244                 return SCSI_DH_RES_TEMP_UNAVAIL;
 245
 246         blk_rq_set_block_pc(req);
 247         req->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 248                           REQ_FAILFAST_DRIVER;
 249         req->cmd_len = COMMAND_SIZE(START_STOP);
 250         req->cmd[0] = START_STOP;
 251         req->cmd[4] = 1;        /* Start spin cycle */
 252         req->timeout = HP_SW_TIMEOUT;
 253         req->sense = h->sense;
 254         memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE);
 255         req->sense_len = 0;
 256         req->end_io_data = h;
 257
 258         blk_execute_rq_nowait(req->q, NULL, req, 1, start_stop_endio);
 259         return SCSI_DH_OK;
 260 }
 261
 262 static int hp_sw_prep_fn(struct scsi_device *sdev, struct request *req)
 263 {
 264         struct hp_sw_dh_data *h = sdev->handler_data;
 265         int ret = BLKPREP_OK;
 266
 267         if (h->path_state != HP_SW_PATH_ACTIVE) {
 268                 ret = BLKPREP_KILL;
 269                 req->cmd_flags |= REQ_QUIET;
 270         }
 271         return ret;
 272
 273 }
 274
 275 /*
 276  * hp_sw_activate - Activate a path
 277  * @sdev: sdev on the path to be activated
 278  *
 279  * The HP Active/Passive firmware is pretty simple;
 280  * the passive path reports NOT READY with sense codes
 281  * 0x04/0x02; a START STOP UNIT command will then
 282  * activate the passive path (and deactivate the
 283  * previously active one).
 284  */
 285 static int hp_sw_activate(struct scsi_device *sdev,
 286                                 activate_complete fn, void *data)
 287 {
 288         int ret = SCSI_DH_OK;
 289         struct hp_sw_dh_data *h = sdev->handler_data;
 290
 291         ret = hp_sw_tur(sdev, h);
 292
 293         if (ret == SCSI_DH_OK && h->path_state == HP_SW_PATH_PASSIVE) {
 294                 h->retry_cnt = h->retries;
 295                 h->callback_fn = fn;
 296                 h->callback_data = data;
 297                 ret = hp_sw_start_stop(h);
 298                 if (ret == SCSI_DH_OK)
 299                         return 0;
 300                 h->callback_fn = h->callback_data = NULL;
 301         }
 302
 303         if (fn)
 304                 fn(data, ret);
 305         return 0;
 306 }
 307
 308 static int hp_sw_bus_attach(struct scsi_device *sdev)
 309 {
 310         struct hp_sw_dh_data *h;
 311         int ret;
 312
 313         h = kzalloc(sizeof(*h), GFP_KERNEL);
 314         if (!h)
 315                 return -ENOMEM;
 316         h->path_state = HP_SW_PATH_UNINITIALIZED;
 317         h->retries = HP_SW_RETRIES;
 318         h->sdev = sdev;
 319
 320         ret = hp_sw_tur(sdev, h);
 321         if (ret != SCSI_DH_OK || h->path_state == HP_SW_PATH_UNINITIALIZED)
 322                 goto failed;
 323
 324         sdev_printk(KERN_INFO, sdev, "%s: attached to %s path\n",
 325                     HP_SW_NAME, h->path_state == HP_SW_PATH_ACTIVE?
 326                     "active":"passive");
 327
 328         sdev->handler_data = h;
 329         return 0;
 330 failed:
 331         kfree(h);
 332         return -EINVAL;
 333 }
 334
 335 static void hp_sw_bus_detach( struct scsi_device *sdev )
 336 {
 337         kfree(sdev->handler_data);
 338         sdev->handler_data = NULL;
 339 }
 340
 341 static struct scsi_device_handler hp_sw_dh = {
 342         .name           = HP_SW_NAME,
 343         .module         = THIS_MODULE,
 344         .attach         = hp_sw_bus_attach,
 345         .detach         = hp_sw_bus_detach,
 346         .activate       = hp_sw_activate,
 347         .prep_fn        = hp_sw_prep_fn,
 348 };
 349
 350 static int __init hp_sw_init(void)
 351 {
 352         return scsi_register_device_handler(&hp_sw_dh);
 353 }
 354
 355 static void __exit hp_sw_exit(void)
 356 {
 357         scsi_unregister_device_handler(&hp_sw_dh);
 358 }
 359
 360 module_init(hp_sw_init);
 361 module_exit(hp_sw_exit);
 362
 363 MODULE_DESCRIPTION("HP Active/Passive driver");
 364 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu");
 365 MODULE_LICENSE("GPL");