drivers/scsi/ch.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * SCSI Media Changer device driver for Linux 2.6
   4  *
   5  *     (c) 1996-2003 Gerd Knorr <kraxel@bytesex.org>
   6  *
   7  */
   8
   9 #define VERSION "0.25"
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/fs.h>
  14 #include <linux/kernel.h>
  15 #include <linux/mm.h>
  16 #include <linux/major.h>
  17 #include <linux/string.h>
  18 #include <linux/errno.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/completion.h>
  22 #include <linux/compat.h>
  23 #include <linux/chio.h>                 /* here are all the ioctls */
  24 #include <linux/mutex.h>
  25 #include <linux/idr.h>
  26 #include <linux/slab.h>
  27
  28 #include <scsi/scsi.h>
  29 #include <scsi/scsi_cmnd.h>
  30 #include <scsi/scsi_driver.h>
  31 #include <scsi/scsi_ioctl.h>
  32 #include <scsi/scsi_host.h>
  33 #include <scsi/scsi_device.h>
  34 #include <scsi/scsi_eh.h>
  35 #include <scsi/scsi_dbg.h>
  36
  37 #define CH_DT_MAX       16
  38 #define CH_TYPES        8
  39 #define CH_MAX_DEVS     128
  40
  41 MODULE_DESCRIPTION("device driver for scsi media changer devices");
  42 MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org>");
  43 MODULE_LICENSE("GPL");
  44 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_CHANGER_MAJOR);
  45 MODULE_ALIAS_SCSI_DEVICE(TYPE_MEDIUM_CHANGER);
  46
  47 static int init = 1;
  48 module_param(init, int, 0444);
  49 MODULE_PARM_DESC(init, \
  50     "initialize element status on driver load (default: on)");
  51
  52 static int timeout_move = 300;
  53 module_param(timeout_move, int, 0644);
  54 MODULE_PARM_DESC(timeout_move,"timeout for move commands "
  55                  "(default: 300 seconds)");
  56
  57 static int timeout_init = 3600;
  58 module_param(timeout_init, int, 0644);
  59 MODULE_PARM_DESC(timeout_init,"timeout for INITIALIZE ELEMENT STATUS "
  60                  "(default: 3600 seconds)");
  61
  62 static int verbose = 1;
  63 module_param(verbose, int, 0644);
  64 MODULE_PARM_DESC(verbose,"be verbose (default: on)");
  65
  66 static int debug = 0;
  67 module_param(debug, int, 0644);
  68 MODULE_PARM_DESC(debug,"enable/disable debug messages, also prints more "
  69                  "detailed sense codes on scsi errors (default: off)");
  70
  71 static int dt_id[CH_DT_MAX] = { [ 0 ... (CH_DT_MAX-1) ] = -1 };
  72 static int dt_lun[CH_DT_MAX];
  73 module_param_array(dt_id,  int, NULL, 0444);
  74 module_param_array(dt_lun, int, NULL, 0444);
  75
  76 /* tell the driver about vendor-specific slots */
  77 static int vendor_firsts[CH_TYPES-4];
  78 static int vendor_counts[CH_TYPES-4];
  79 module_param_array(vendor_firsts, int, NULL, 0444);
  80 module_param_array(vendor_counts, int, NULL, 0444);
  81
  82 static const char * vendor_labels[CH_TYPES-4] = {
  83         "v0", "v1", "v2", "v3"
  84 };
  85 // module_param_string_array(vendor_labels, NULL, 0444);
  86
  87 #define ch_printk(prefix, ch, fmt, a...) \
  88         sdev_prefix_printk(prefix, (ch)->device, (ch)->name, fmt, ##a)
  89
  90 #define DPRINTK(fmt, arg...)                                            \
  91 do {                                                                    \
  92         if (debug)                                                      \
  93                 ch_printk(KERN_DEBUG, ch, fmt, ##arg);                  \
  94 } while (0)
  95 #define VPRINTK(level, fmt, arg...)                                     \
  96 do {                                                                    \
  97         if (verbose)                                                    \
  98                 ch_printk(level, ch, fmt, ##arg);                       \
  99 } while (0)
 100
 101 /* ------------------------------------------------------------------- */
 102
 103 #define MAX_RETRIES   1
 104
 105 static struct class * ch_sysfs_class;
 106
 107 typedef struct {
 108         struct kref         ref;
 109         struct list_head    list;
 110         int                 minor;
 111         char                name[8];
 112         struct scsi_device  *device;
 113         struct scsi_device  **dt;        /* ptrs to data transfer elements */
 114         u_int               firsts[CH_TYPES];
 115         u_int               counts[CH_TYPES];
 116         u_int               unit_attention;
 117         u_int               voltags;
 118         struct mutex        lock;
 119 } scsi_changer;
 120
 121 static DEFINE_IDR(ch_index_idr);
 122 static DEFINE_SPINLOCK(ch_index_lock);
 123
 124 static const struct {
 125         unsigned char  sense;
 126         unsigned char  asc;
 127         unsigned char  ascq;
 128         int            errno;
 129 } ch_err[] = {
 130 /* Just filled in what looks right. Hav'nt checked any standard paper for
 131    these errno assignments, so they may be wrong... */
 132         {
 133                 .sense  = ILLEGAL_REQUEST,
 134                 .asc    = 0x21,
 135                 .ascq   = 0x01,
 136                 .errno  = EBADSLT, /* Invalid element address */
 137         },{
 138                 .sense  = ILLEGAL_REQUEST,
 139                 .asc    = 0x28,
 140                 .ascq   = 0x01,
 141                 .errno  = EBADE,   /* Import or export element accessed */
 142         },{
 143                 .sense  = ILLEGAL_REQUEST,
 144                 .asc    = 0x3B,
 145                 .ascq   = 0x0D,
 146                 .errno  = EXFULL,  /* Medium destination element full */
 147         },{
 148                 .sense  = ILLEGAL_REQUEST,
 149                 .asc    = 0x3B,
 150                 .ascq   = 0x0E,
 151                 .errno  = EBADE,   /* Medium source element empty */
 152         },{
 153                 .sense  = ILLEGAL_REQUEST,
 154                 .asc    = 0x20,
 155                 .ascq   = 0x00,
 156                 .errno  = EBADRQC, /* Invalid command operation code */
 157         },{
 158                 /* end of list */
 159         }
 160 };
 161
 162 /* ------------------------------------------------------------------- */
 163
 164 static int ch_find_errno(struct scsi_sense_hdr *sshdr)
 165 {
 166         int i,errno = 0;
 167
 168         /* Check to see if additional sense information is available */
 169         if (scsi_sense_valid(sshdr) &&
 170             sshdr->asc != 0) {
 171                 for (i = 0; ch_err[i].errno != 0; i++) {
 172                         if (ch_err[i].sense == sshdr->sense_key &&
 173                             ch_err[i].asc   == sshdr->asc &&
 174                             ch_err[i].ascq  == sshdr->ascq) {
 175                                 errno = -ch_err[i].errno;
 176                                 break;
 177                         }
 178                 }
 179         }
 180         if (errno == 0)
 181                 errno = -EIO;
 182         return errno;
 183 }
 184
 185 static int
 186 ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
 187            void *buffer, unsigned buflength,
 188            enum dma_data_direction direction)
 189 {
 190         int errno, retries = 0, timeout, result;
 191         struct scsi_sense_hdr sshdr;
 192
 193         timeout = (cmd[0] == INITIALIZE_ELEMENT_STATUS)
 194                 ? timeout_init : timeout_move;
 195
 196  retry:
 197         errno = 0;
 198         result = scsi_execute_req(ch->device, cmd, direction, buffer,
 199                                   buflength, &sshdr, timeout * HZ,
 200                                   MAX_RETRIES, NULL);
 201         if (result < 0)
 202                 return result;
 203         if (scsi_sense_valid(&sshdr)) {
 204                 if (debug)
 205                         scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
 206                 errno = ch_find_errno(&sshdr);
 207
 208                 switch(sshdr.sense_key) {
 209                 case UNIT_ATTENTION:
 210                         ch->unit_attention = 1;
 211                         if (retries++ < 3)
 212                                 goto retry;
 213                         break;
 214                 }
 215         }
 216         return errno;
 217 }
 218
 219 /* ------------------------------------------------------------------------ */
 220
 221 static int
 222 ch_elem_to_typecode(scsi_changer *ch, u_int elem)
 223 {
 224         int i;
 225
 226         for (i = 0; i < CH_TYPES; i++) {
 227                 if (elem >= ch->firsts[i]  &&
 228                     elem <  ch->firsts[i] +
 229                     ch->counts[i])
 230                         return i+1;
 231         }
 232         return 0;
 233 }
 234
 235 static int
 236 ch_read_element_status(scsi_changer *ch, u_int elem, char *data)
 237 {
 238         u_char  cmd[12];
 239         u_char  *buffer;
 240         int     result;
 241
 242         buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
 243         if(!buffer)
 244                 return -ENOMEM;
 245
 246  retry:
 247         memset(cmd,0,sizeof(cmd));
 248         cmd[0] = READ_ELEMENT_STATUS;
 249         cmd[1] = ((ch->device->lun & 0x7) << 5) |
 250                 (ch->voltags ? 0x10 : 0) |
 251                 ch_elem_to_typecode(ch,elem);
 252         cmd[2] = (elem >> 8) & 0xff;
 253         cmd[3] = elem        & 0xff;
 254         cmd[5] = 1;
 255         cmd[9] = 255;
 256         if (0 == (result = ch_do_scsi(ch, cmd, 12,
 257                                       buffer, 256, DMA_FROM_DEVICE))) {
 258                 if (((buffer[16] << 8) | buffer[17]) != elem) {
 259                         DPRINTK("asked for element 0x%02x, got 0x%02x\n",
 260                                 elem,(buffer[16] << 8) | buffer[17]);
 261                         kfree(buffer);
 262                         return -EIO;
 263                 }
 264                 memcpy(data,buffer+16,16);
 265         } else {
 266                 if (ch->voltags) {
 267                         ch->voltags = 0;
 268                         VPRINTK(KERN_INFO, "device has no volume tag support\n");
 269                         goto retry;
 270                 }
 271                 DPRINTK("READ ELEMENT STATUS for element 0x%x failed\n",elem);
 272         }
 273         kfree(buffer);
 274         return result;
 275 }
 276
 277 static int
 278 ch_init_elem(scsi_changer *ch)
 279 {
 280         int err;
 281         u_char cmd[6];
 282
 283         VPRINTK(KERN_INFO, "INITIALIZE ELEMENT STATUS, may take some time ...\n");
 284         memset(cmd,0,sizeof(cmd));
 285         cmd[0] = INITIALIZE_ELEMENT_STATUS;
 286         cmd[1] = (ch->device->lun & 0x7) << 5;
 287         err = ch_do_scsi(ch, cmd, 6, NULL, 0, DMA_NONE);
 288         VPRINTK(KERN_INFO, "... finished\n");
 289         return err;
 290 }
 291
 292 static int
 293 ch_readconfig(scsi_changer *ch)
 294 {
 295         u_char  cmd[10], data[16];
 296         u_char  *buffer;
 297         int     result,id,lun,i;
 298         u_int   elem;
 299
 300         buffer = kzalloc(512, GFP_KERNEL | GFP_DMA);
 301         if (!buffer)
 302                 return -ENOMEM;
 303
 304         memset(cmd,0,sizeof(cmd));
 305         cmd[0] = MODE_SENSE;
 306         cmd[1] = (ch->device->lun & 0x7) << 5;
 307         cmd[2] = 0x1d;
 308         cmd[4] = 255;
 309         result = ch_do_scsi(ch, cmd, 10, buffer, 255, DMA_FROM_DEVICE);
 310         if (0 != result) {
 311                 cmd[1] |= (1<<3);
 312                 result  = ch_do_scsi(ch, cmd, 10, buffer, 255, DMA_FROM_DEVICE);
 313         }
 314         if (0 == result) {
 315                 ch->firsts[CHET_MT] =
 316                         (buffer[buffer[3]+ 6] << 8) | buffer[buffer[3]+ 7];
 317                 ch->counts[CHET_MT] =
 318                         (buffer[buffer[3]+ 8] << 8) | buffer[buffer[3]+ 9];
 319                 ch->firsts[CHET_ST] =
 320                         (buffer[buffer[3]+10] << 8) | buffer[buffer[3]+11];
 321                 ch->counts[CHET_ST] =
 322                         (buffer[buffer[3]+12] << 8) | buffer[buffer[3]+13];
 323                 ch->firsts[CHET_IE] =
 324                         (buffer[buffer[3]+14] << 8) | buffer[buffer[3]+15];
 325                 ch->counts[CHET_IE] =
 326                         (buffer[buffer[3]+16] << 8) | buffer[buffer[3]+17];
 327                 ch->firsts[CHET_DT] =
 328                         (buffer[buffer[3]+18] << 8) | buffer[buffer[3]+19];
 329                 ch->counts[CHET_DT] =
 330                         (buffer[buffer[3]+20] << 8) | buffer[buffer[3]+21];
 331                 VPRINTK(KERN_INFO, "type #1 (mt): 0x%x+%d [medium transport]\n",
 332                         ch->firsts[CHET_MT],
 333                         ch->counts[CHET_MT]);
 334                 VPRINTK(KERN_INFO, "type #2 (st): 0x%x+%d [storage]\n",
 335                         ch->firsts[CHET_ST],
 336                         ch->counts[CHET_ST]);
 337                 VPRINTK(KERN_INFO, "type #3 (ie): 0x%x+%d [import/export]\n",
 338                         ch->firsts[CHET_IE],
 339                         ch->counts[CHET_IE]);
 340                 VPRINTK(KERN_INFO, "type #4 (dt): 0x%x+%d [data transfer]\n",
 341                         ch->firsts[CHET_DT],
 342                         ch->counts[CHET_DT]);
 343         } else {
 344                 VPRINTK(KERN_INFO, "reading element address assignment page failed!\n");
 345         }
 346
 347         /* vendor specific element types */
 348         for (i = 0; i < 4; i++) {
 349                 if (0 == vendor_counts[i])
 350                         continue;
 351                 if (NULL == vendor_labels[i])
 352                         continue;
 353                 ch->firsts[CHET_V1+i] = vendor_firsts[i];
 354                 ch->counts[CHET_V1+i] = vendor_counts[i];
 355                 VPRINTK(KERN_INFO, "type #%d (v%d): 0x%x+%d [%s, vendor specific]\n",
 356                         i+5,i+1,vendor_firsts[i],vendor_counts[i],
 357                         vendor_labels[i]);
 358         }
 359
 360         /* look up the devices of the data transfer elements */
 361         ch->dt = kcalloc(ch->counts[CHET_DT], sizeof(*ch->dt),
 362                          GFP_KERNEL);
 363
 364         if (!ch->dt) {
 365                 kfree(buffer);
 366                 return -ENOMEM;
 367         }
 368
 369         for (elem = 0; elem < ch->counts[CHET_DT]; elem++) {
 370                 id  = -1;
 371                 lun = 0;
 372                 if (elem < CH_DT_MAX  &&  -1 != dt_id[elem]) {
 373                         id  = dt_id[elem];
 374                         lun = dt_lun[elem];
 375                         VPRINTK(KERN_INFO, "dt 0x%x: [insmod option] ",
 376                                 elem+ch->firsts[CHET_DT]);
 377                 } else if (0 != ch_read_element_status
 378                            (ch,elem+ch->firsts[CHET_DT],data)) {
 379                         VPRINTK(KERN_INFO, "dt 0x%x: READ ELEMENT STATUS failed\n",
 380                                 elem+ch->firsts[CHET_DT]);
 381                 } else {
 382                         VPRINTK(KERN_INFO, "dt 0x%x: ",elem+ch->firsts[CHET_DT]);
 383                         if (data[6] & 0x80) {
 384                                 VPRINTK(KERN_CONT, "not this SCSI bus\n");
 385                                 ch->dt[elem] = NULL;
 386                         } else if (0 == (data[6] & 0x30)) {
 387                                 VPRINTK(KERN_CONT, "ID/LUN unknown\n");
 388                                 ch->dt[elem] = NULL;
 389                         } else {
 390                                 id  = ch->device->id;
 391                                 lun = 0;
 392                                 if (data[6] & 0x20) id  = data[7];
 393                                 if (data[6] & 0x10) lun = data[6] & 7;
 394                         }
 395                 }
 396                 if (-1 != id) {
 397                         VPRINTK(KERN_CONT, "ID %i, LUN %i, ",id,lun);
 398                         ch->dt[elem] =
 399                                 scsi_device_lookup(ch->device->host,
 400                                                    ch->device->channel,
 401                                                    id,lun);
 402                         if (!ch->dt[elem]) {
 403                                 /* should not happen */
 404                                 VPRINTK(KERN_CONT, "Huh? device not found!\n");
 405                         } else {
 406                                 VPRINTK(KERN_CONT, "name: %8.8s %16.16s %4.4s\n",
 407                                         ch->dt[elem]->vendor,
 408                                         ch->dt[elem]->model,
 409                                         ch->dt[elem]->rev);
 410                         }
 411                 }
 412         }
 413         ch->voltags = 1;
 414         kfree(buffer);
 415
 416         return 0;
 417 }
 418
 419 /* ------------------------------------------------------------------------ */
 420
 421 static int
 422 ch_position(scsi_changer *ch, u_int trans, u_int elem, int rotate)
 423 {
 424         u_char  cmd[10];
 425
 426         DPRINTK("position: 0x%x\n",elem);
 427         if (0 == trans)
 428                 trans = ch->firsts[CHET_MT];
 429         memset(cmd,0,sizeof(cmd));
 430         cmd[0]  = POSITION_TO_ELEMENT;
 431         cmd[1]  = (ch->device->lun & 0x7) << 5;
 432         cmd[2]  = (trans >> 8) & 0xff;
 433         cmd[3]  =  trans       & 0xff;
 434         cmd[4]  = (elem  >> 8) & 0xff;
 435         cmd[5]  =  elem        & 0xff;
 436         cmd[8]  = rotate ? 1 : 0;
 437         return ch_do_scsi(ch, cmd, 10, NULL, 0, DMA_NONE);
 438 }
 439
 440 static int
 441 ch_move(scsi_changer *ch, u_int trans, u_int src, u_int dest, int rotate)
 442 {
 443         u_char  cmd[12];
 444
 445         DPRINTK("move: 0x%x => 0x%x\n",src,dest);
 446         if (0 == trans)
 447                 trans = ch->firsts[CHET_MT];
 448         memset(cmd,0,sizeof(cmd));
 449         cmd[0]  = MOVE_MEDIUM;
 450         cmd[1]  = (ch->device->lun & 0x7) << 5;
 451         cmd[2]  = (trans >> 8) & 0xff;
 452         cmd[3]  =  trans       & 0xff;
 453         cmd[4]  = (src   >> 8) & 0xff;
 454         cmd[5]  =  src         & 0xff;
 455         cmd[6]  = (dest  >> 8) & 0xff;
 456         cmd[7]  =  dest        & 0xff;
 457         cmd[10] = rotate ? 1 : 0;
 458         return ch_do_scsi(ch, cmd, 12, NULL,0, DMA_NONE);
 459 }
 460
 461 static int
 462 ch_exchange(scsi_changer *ch, u_int trans, u_int src,
 463             u_int dest1, u_int dest2, int rotate1, int rotate2)
 464 {
 465         u_char  cmd[12];
 466
 467         DPRINTK("exchange: 0x%x => 0x%x => 0x%x\n",
 468                 src,dest1,dest2);
 469         if (0 == trans)
 470                 trans = ch->firsts[CHET_MT];
 471         memset(cmd,0,sizeof(cmd));
 472         cmd[0]  = EXCHANGE_MEDIUM;
 473         cmd[1]  = (ch->device->lun & 0x7) << 5;
 474         cmd[2]  = (trans >> 8) & 0xff;
 475         cmd[3]  =  trans       & 0xff;
 476         cmd[4]  = (src   >> 8) & 0xff;
 477         cmd[5]  =  src         & 0xff;
 478         cmd[6]  = (dest1 >> 8) & 0xff;
 479         cmd[7]  =  dest1       & 0xff;
 480         cmd[8]  = (dest2 >> 8) & 0xff;
 481         cmd[9]  =  dest2       & 0xff;
 482         cmd[10] = (rotate1 ? 1 : 0) | (rotate2 ? 2 : 0);
 483
 484         return ch_do_scsi(ch, cmd, 12, NULL, 0, DMA_NONE);
 485 }
 486
 487 static void
 488 ch_check_voltag(char *tag)
 489 {
 490         int i;
 491
 492         for (i = 0; i < 32; i++) {
 493                 /* restrict to ascii */
 494                 if (tag[i] >= 0x7f || tag[i] < 0x20)
 495                         tag[i] = ' ';
 496                 /* don't allow search wildcards */
 497                 if (tag[i] == '?' ||
 498                     tag[i] == '*')
 499                         tag[i] = ' ';
 500         }
 501 }
 502
 503 static int
 504 ch_set_voltag(scsi_changer *ch, u_int elem,
 505               int alternate, int clear, u_char *tag)
 506 {
 507         u_char  cmd[12];
 508         u_char  *buffer;
 509         int result;
 510
 511         buffer = kzalloc(512, GFP_KERNEL);
 512         if (!buffer)
 513                 return -ENOMEM;
 514
 515         DPRINTK("%s %s voltag: 0x%x => \"%s\"\n",
 516                 clear     ? "clear"     : "set",
 517                 alternate ? "alternate" : "primary",
 518                 elem, tag);
 519         memset(cmd,0,sizeof(cmd));
 520         cmd[0]  = SEND_VOLUME_TAG;
 521         cmd[1] = ((ch->device->lun & 0x7) << 5) |
 522                 ch_elem_to_typecode(ch,elem);
 523         cmd[2] = (elem >> 8) & 0xff;
 524         cmd[3] = elem        & 0xff;
 525         cmd[5] = clear
 526                 ? (alternate ? 0x0d : 0x0c)
 527                 : (alternate ? 0x0b : 0x0a);
 528
 529         cmd[9] = 255;
 530
 531         memcpy(buffer,tag,32);
 532         ch_check_voltag(buffer);
 533
 534         result = ch_do_scsi(ch, cmd, 12, buffer, 256, DMA_TO_DEVICE);
 535         kfree(buffer);
 536         return result;
 537 }
 538
 539 static int ch_gstatus(scsi_changer *ch, int type, unsigned char __user *dest)
 540 {
 541         int retval = 0;
 542         u_char data[16];
 543         unsigned int i;
 544
 545         mutex_lock(&ch->lock);
 546         for (i = 0; i < ch->counts[type]; i++) {
 547                 if (0 != ch_read_element_status
 548                     (ch, ch->firsts[type]+i,data)) {
 549                         retval = -EIO;
 550                         break;
 551                 }
 552                 put_user(data[2], dest+i);
 553                 if (data[2] & CESTATUS_EXCEPT)
 554                         VPRINTK(KERN_INFO, "element 0x%x: asc=0x%x, ascq=0x%x\n",
 555                                 ch->firsts[type]+i,
 556                                 (int)data[4],(int)data[5]);
 557                 retval = ch_read_element_status
 558                         (ch, ch->firsts[type]+i,data);
 559                 if (0 != retval)
 560                         break;
 561         }
 562         mutex_unlock(&ch->lock);
 563         return retval;
 564 }
 565
 566 /* ------------------------------------------------------------------------ */
 567
 568 static void ch_destroy(struct kref *ref)
 569 {
 570         scsi_changer *ch = container_of(ref, scsi_changer, ref);
 571
 572         ch->device = NULL;
 573         kfree(ch->dt);
 574         kfree(ch);
 575 }
 576
 577 static int
 578 ch_release(struct inode *inode, struct file *file)
 579 {
 580         scsi_changer *ch = file->private_data;
 581
 582         scsi_device_put(ch->device);
 583         file->private_data = NULL;
 584         kref_put(&ch->ref, ch_destroy);
 585         return 0;
 586 }
 587
 588 static int
 589 ch_open(struct inode *inode, struct file *file)
 590 {
 591         scsi_changer *ch;
 592         int minor = iminor(inode);
 593
 594         spin_lock(&ch_index_lock);
 595         ch = idr_find(&ch_index_idr, minor);
 596
 597         if (ch == NULL || !kref_get_unless_zero(&ch->ref)) {
 598                 spin_unlock(&ch_index_lock);
 599                 return -ENXIO;
 600         }
 601         spin_unlock(&ch_index_lock);
 602         if (scsi_device_get(ch->device)) {
 603                 kref_put(&ch->ref, ch_destroy);
 604                 return -ENXIO;
 605         }
 606         /* Synchronize with ch_probe() */
 607         mutex_lock(&ch->lock);
 608         file->private_data = ch;
 609         mutex_unlock(&ch->lock);
 610         return 0;
 611 }
 612
 613 static int
 614 ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
 615 {
 616         if (type >= CH_TYPES  ||  unit >= ch->counts[type])
 617                 return -1;
 618         return 0;
 619 }
 620
 621 struct changer_element_status32 {
 622         int             ces_type;
 623         compat_uptr_t   ces_data;
 624 };
 625 #define CHIOGSTATUS32  _IOW('c', 8, struct changer_element_status32)
 626
 627 static long ch_ioctl(struct file *file,
 628                     unsigned int cmd, unsigned long arg)
 629 {
 630         scsi_changer *ch = file->private_data;
 631         int retval;
 632         void __user *argp = (void __user *)arg;
 633
 634         retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
 635                         file->f_flags & O_NDELAY);
 636         if (retval)
 637                 return retval;
 638
 639         switch (cmd) {
 640         case CHIOGPARAMS:
 641         {
 642                 struct changer_params params;
 643
 644                 params.cp_curpicker = 0;
 645                 params.cp_npickers  = ch->counts[CHET_MT];
 646                 params.cp_nslots    = ch->counts[CHET_ST];
 647                 params.cp_nportals  = ch->counts[CHET_IE];
 648                 params.cp_ndrives   = ch->counts[CHET_DT];
 649
 650                 if (copy_to_user(argp, &params, sizeof(params)))
 651                         return -EFAULT;
 652                 return 0;
 653         }
 654         case CHIOGVPARAMS:
 655         {
 656                 struct changer_vendor_params vparams;
 657
 658                 memset(&vparams,0,sizeof(vparams));
 659                 if (ch->counts[CHET_V1]) {
 660                         vparams.cvp_n1  = ch->counts[CHET_V1];
 661                         strncpy(vparams.cvp_label1,vendor_labels[0],16);
 662                 }
 663                 if (ch->counts[CHET_V2]) {
 664                         vparams.cvp_n2  = ch->counts[CHET_V2];
 665                         strncpy(vparams.cvp_label2,vendor_labels[1],16);
 666                 }
 667                 if (ch->counts[CHET_V3]) {
 668                         vparams.cvp_n3  = ch->counts[CHET_V3];
 669                         strncpy(vparams.cvp_label3,vendor_labels[2],16);
 670                 }
 671                 if (ch->counts[CHET_V4]) {
 672                         vparams.cvp_n4  = ch->counts[CHET_V4];
 673                         strncpy(vparams.cvp_label4,vendor_labels[3],16);
 674                 }
 675                 if (copy_to_user(argp, &vparams, sizeof(vparams)))
 676                         return -EFAULT;
 677                 return 0;
 678         }
 679
 680         case CHIOPOSITION:
 681         {
 682                 struct changer_position pos;
 683
 684                 if (copy_from_user(&pos, argp, sizeof (pos)))
 685                         return -EFAULT;
 686
 687                 if (0 != ch_checkrange(ch, pos.cp_type, pos.cp_unit)) {
 688                         DPRINTK("CHIOPOSITION: invalid parameter\n");
 689                         return -EBADSLT;
 690                 }
 691                 mutex_lock(&ch->lock);
 692                 retval = ch_position(ch,0,
 693                                      ch->firsts[pos.cp_type] + pos.cp_unit,
 694                                      pos.cp_flags & CP_INVERT);
 695                 mutex_unlock(&ch->lock);
 696                 return retval;
 697         }
 698
 699         case CHIOMOVE:
 700         {
 701                 struct changer_move mv;
 702
 703                 if (copy_from_user(&mv, argp, sizeof (mv)))
 704                         return -EFAULT;
 705
 706                 if (0 != ch_checkrange(ch, mv.cm_fromtype, mv.cm_fromunit) ||
 707                     0 != ch_checkrange(ch, mv.cm_totype,   mv.cm_tounit  )) {
 708                         DPRINTK("CHIOMOVE: invalid parameter\n");
 709                         return -EBADSLT;
 710                 }
 711
 712                 mutex_lock(&ch->lock);
 713                 retval = ch_move(ch,0,
 714                                  ch->firsts[mv.cm_fromtype] + mv.cm_fromunit,
 715                                  ch->firsts[mv.cm_totype]   + mv.cm_tounit,
 716                                  mv.cm_flags & CM_INVERT);
 717                 mutex_unlock(&ch->lock);
 718                 return retval;
 719         }
 720
 721         case CHIOEXCHANGE:
 722         {
 723                 struct changer_exchange mv;
 724
 725                 if (copy_from_user(&mv, argp, sizeof (mv)))
 726                         return -EFAULT;
 727
 728                 if (0 != ch_checkrange(ch, mv.ce_srctype,  mv.ce_srcunit ) ||
 729                     0 != ch_checkrange(ch, mv.ce_fdsttype, mv.ce_fdstunit) ||
 730                     0 != ch_checkrange(ch, mv.ce_sdsttype, mv.ce_sdstunit)) {
 731                         DPRINTK("CHIOEXCHANGE: invalid parameter\n");
 732                         return -EBADSLT;
 733                 }
 734
 735                 mutex_lock(&ch->lock);
 736                 retval = ch_exchange
 737                         (ch,0,
 738                          ch->firsts[mv.ce_srctype]  + mv.ce_srcunit,
 739                          ch->firsts[mv.ce_fdsttype] + mv.ce_fdstunit,
 740                          ch->firsts[mv.ce_sdsttype] + mv.ce_sdstunit,
 741                          mv.ce_flags & CE_INVERT1, mv.ce_flags & CE_INVERT2);
 742                 mutex_unlock(&ch->lock);
 743                 return retval;
 744         }
 745
 746         case CHIOGSTATUS:
 747         {
 748                 struct changer_element_status ces;
 749
 750                 if (copy_from_user(&ces, argp, sizeof (ces)))
 751                         return -EFAULT;
 752                 if (ces.ces_type < 0 || ces.ces_type >= CH_TYPES)
 753                         return -EINVAL;
 754
 755                 return ch_gstatus(ch, ces.ces_type, ces.ces_data);
 756         }
 757 #ifdef CONFIG_COMPAT
 758         case CHIOGSTATUS32:
 759         {
 760                 struct changer_element_status32 ces32;
 761
 762                 if (copy_from_user(&ces32, argp, sizeof(ces32)))
 763                         return -EFAULT;
 764                 if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
 765                         return -EINVAL;
 766
 767                 return ch_gstatus(ch, ces32.ces_type,
 768                                   compat_ptr(ces32.ces_data));
 769         }
 770 #endif
 771         case CHIOGELEM:
 772         {
 773                 struct changer_get_element cge;
 774                 u_char ch_cmd[12];
 775                 u_char *buffer;
 776                 unsigned int elem;
 777                 int     result,i;
 778
 779                 if (copy_from_user(&cge, argp, sizeof (cge)))
 780                         return -EFAULT;
 781
 782                 if (0 != ch_checkrange(ch, cge.cge_type, cge.cge_unit))
 783                         return -EINVAL;
 784                 elem = ch->firsts[cge.cge_type] + cge.cge_unit;
 785
 786                 buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
 787                 if (!buffer)
 788                         return -ENOMEM;
 789                 mutex_lock(&ch->lock);
 790
 791         voltag_retry:
 792                 memset(ch_cmd, 0, sizeof(ch_cmd));
 793                 ch_cmd[0] = READ_ELEMENT_STATUS;
 794                 ch_cmd[1] = ((ch->device->lun & 0x7) << 5) |
 795                         (ch->voltags ? 0x10 : 0) |
 796                         ch_elem_to_typecode(ch,elem);
 797                 ch_cmd[2] = (elem >> 8) & 0xff;
 798                 ch_cmd[3] = elem        & 0xff;
 799                 ch_cmd[5] = 1;
 800                 ch_cmd[9] = 255;
 801
 802                 result = ch_do_scsi(ch, ch_cmd, 12,
 803                                     buffer, 256, DMA_FROM_DEVICE);
 804                 if (!result) {
 805                         cge.cge_status = buffer[18];
 806                         cge.cge_flags = 0;
 807                         if (buffer[18] & CESTATUS_EXCEPT) {
 808                                 cge.cge_errno = EIO;
 809                         }
 810                         if (buffer[25] & 0x80) {
 811                                 cge.cge_flags |= CGE_SRC;
 812                                 if (buffer[25] & 0x40)
 813                                         cge.cge_flags |= CGE_INVERT;
 814                                 elem = (buffer[26]<<8) | buffer[27];
 815                                 for (i = 0; i < 4; i++) {
 816                                         if (elem >= ch->firsts[i] &&
 817                                             elem <  ch->firsts[i] + ch->counts[i]) {
 818                                                 cge.cge_srctype = i;
 819                                                 cge.cge_srcunit = elem-ch->firsts[i];
 820                                         }
 821                                 }
 822                         }
 823                         if ((buffer[22] & 0x30) == 0x30) {
 824                                 cge.cge_flags |= CGE_IDLUN;
 825                                 cge.cge_id  = buffer[23];
 826                                 cge.cge_lun = buffer[22] & 7;
 827                         }
 828                         if (buffer[9] & 0x80) {
 829                                 cge.cge_flags |= CGE_PVOLTAG;
 830                                 memcpy(cge.cge_pvoltag,buffer+28,36);
 831                         }
 832                         if (buffer[9] & 0x40) {
 833                                 cge.cge_flags |= CGE_AVOLTAG;
 834                                 memcpy(cge.cge_avoltag,buffer+64,36);
 835                         }
 836                 } else if (ch->voltags) {
 837                         ch->voltags = 0;
 838                         VPRINTK(KERN_INFO, "device has no volume tag support\n");
 839                         goto voltag_retry;
 840                 }
 841                 kfree(buffer);
 842                 mutex_unlock(&ch->lock);
 843
 844                 if (copy_to_user(argp, &cge, sizeof (cge)))
 845                         return -EFAULT;
 846                 return result;
 847         }
 848
 849         case CHIOINITELEM:
 850         {
 851                 mutex_lock(&ch->lock);
 852                 retval = ch_init_elem(ch);
 853                 mutex_unlock(&ch->lock);
 854                 return retval;
 855         }
 856
 857         case CHIOSVOLTAG:
 858         {
 859                 struct changer_set_voltag csv;
 860                 int elem;
 861
 862                 if (copy_from_user(&csv, argp, sizeof(csv)))
 863                         return -EFAULT;
 864
 865                 if (0 != ch_checkrange(ch, csv.csv_type, csv.csv_unit)) {
 866                         DPRINTK("CHIOSVOLTAG: invalid parameter\n");
 867                         return -EBADSLT;
 868                 }
 869                 elem = ch->firsts[csv.csv_type] + csv.csv_unit;
 870                 mutex_lock(&ch->lock);
 871                 retval = ch_set_voltag(ch, elem,
 872                                        csv.csv_flags & CSV_AVOLTAG,
 873                                        csv.csv_flags & CSV_CLEARTAG,
 874                                        csv.csv_voltag);
 875                 mutex_unlock(&ch->lock);
 876                 return retval;
 877         }
 878
 879         default:
 880                 return scsi_ioctl(ch->device, NULL, file->f_mode, cmd, argp);
 881
 882         }
 883 }
 884
 885 /* ------------------------------------------------------------------------ */
 886
 887 static int ch_probe(struct device *dev)
 888 {
 889         struct scsi_device *sd = to_scsi_device(dev);
 890         struct device *class_dev;
 891         int ret;
 892         scsi_changer *ch;
 893
 894         if (sd->type != TYPE_MEDIUM_CHANGER)
 895                 return -ENODEV;
 896
 897         ch = kzalloc(sizeof(*ch), GFP_KERNEL);
 898         if (NULL == ch)
 899                 return -ENOMEM;
 900
 901         idr_preload(GFP_KERNEL);
 902         spin_lock(&ch_index_lock);
 903         ret = idr_alloc(&ch_index_idr, ch, 0, CH_MAX_DEVS + 1, GFP_NOWAIT);
 904         spin_unlock(&ch_index_lock);
 905         idr_preload_end();
 906
 907         if (ret < 0) {
 908                 if (ret == -ENOSPC)
 909                         ret = -ENODEV;
 910                 goto free_ch;
 911         }
 912
 913         ch->minor = ret;
 914         sprintf(ch->name,"ch%d",ch->minor);
 915         ret = scsi_device_get(sd);
 916         if (ret) {
 917                 sdev_printk(KERN_WARNING, sd, "ch%d: failed to get device\n",
 918                             ch->minor);
 919                 goto remove_idr;
 920         }
 921
 922         mutex_init(&ch->lock);
 923         kref_init(&ch->ref);
 924         ch->device = sd;
 925         class_dev = device_create(ch_sysfs_class, dev,
 926                                   MKDEV(SCSI_CHANGER_MAJOR, ch->minor), ch,
 927                                   "s%s", ch->name);
 928         if (IS_ERR(class_dev)) {
 929                 sdev_printk(KERN_WARNING, sd, "ch%d: device_create failed\n",
 930                             ch->minor);
 931                 ret = PTR_ERR(class_dev);
 932                 goto put_device;
 933         }
 934
 935         mutex_lock(&ch->lock);
 936         ret = ch_readconfig(ch);
 937         if (ret) {
 938                 mutex_unlock(&ch->lock);
 939                 goto destroy_dev;
 940         }
 941         if (init)
 942                 ch_init_elem(ch);
 943
 944         mutex_unlock(&ch->lock);
 945         dev_set_drvdata(dev, ch);
 946         sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
 947
 948         return 0;
 949 destroy_dev:
 950         device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
 951 put_device:
 952         scsi_device_put(sd);
 953 remove_idr:
 954         idr_remove(&ch_index_idr, ch->minor);
 955 free_ch:
 956         kfree(ch);
 957         return ret;
 958 }
 959
 960 static int ch_remove(struct device *dev)
 961 {
 962         scsi_changer *ch = dev_get_drvdata(dev);
 963
 964         spin_lock(&ch_index_lock);
 965         idr_remove(&ch_index_idr, ch->minor);
 966         dev_set_drvdata(dev, NULL);
 967         spin_unlock(&ch_index_lock);
 968
 969         device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR,ch->minor));
 970         scsi_device_put(ch->device);
 971         kref_put(&ch->ref, ch_destroy);
 972         return 0;
 973 }
 974
 975 static struct scsi_driver ch_template = {
 976         .gendrv         = {
 977                 .name   = "ch",
 978                 .owner  = THIS_MODULE,
 979                 .probe  = ch_probe,
 980                 .remove = ch_remove,
 981         },
 982 };
 983
 984 static const struct file_operations changer_fops = {
 985         .owner          = THIS_MODULE,
 986         .open           = ch_open,
 987         .release        = ch_release,
 988         .unlocked_ioctl = ch_ioctl,
 989         .compat_ioctl   = compat_ptr_ioctl,
 990         .llseek         = noop_llseek,
 991 };
 992
 993 static int __init init_ch_module(void)
 994 {
 995         int rc;
 996
 997         printk(KERN_INFO "SCSI Media Changer driver v" VERSION " \n");
 998         ch_sysfs_class = class_create(THIS_MODULE, "scsi_changer");
 999         if (IS_ERR(ch_sysfs_class)) {
1000                 rc = PTR_ERR(ch_sysfs_class);
1001                 return rc;
1002         }
1003         rc = register_chrdev(SCSI_CHANGER_MAJOR,"ch",&changer_fops);
1004         if (rc < 0) {
1005                 printk("Unable to get major %d for SCSI-Changer\n",
1006                        SCSI_CHANGER_MAJOR);
1007                 goto fail1;
1008         }
1009         rc = scsi_register_driver(&ch_template.gendrv);
1010         if (rc < 0)
1011                 goto fail2;
1012         return 0;
1013
1014  fail2:
1015         unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1016  fail1:
1017         class_destroy(ch_sysfs_class);
1018         return rc;
1019 }
1020
1021 static void __exit exit_ch_module(void)
1022 {
1023         scsi_unregister_driver(&ch_template.gendrv);
1024         unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1025         class_destroy(ch_sysfs_class);
1026         idr_destroy(&ch_index_idr);
1027 }
1028
1029 module_init(init_ch_module);
1030 module_exit(exit_ch_module);