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;
  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 int buflength, enum req_op op)
 188 {
 189         int errno, retries = 0, timeout, result;
 190         struct scsi_sense_hdr sshdr;
 191         const struct scsi_exec_args exec_args = {
 192                 .sshdr = &sshdr,
 193         };
 194
 195         timeout = (cmd[0] == INITIALIZE_ELEMENT_STATUS)
 196                 ? timeout_init : timeout_move;
 197
 198  retry:
 199         errno = 0;
 200         result = scsi_execute_cmd(ch->device, cmd, op, buffer, buflength,
 201                                   timeout * HZ, MAX_RETRIES, &exec_args);
 202         if (result < 0)
 203                 return result;
 204         if (scsi_sense_valid(&sshdr)) {
 205                 if (debug)
 206                         scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
 207                 errno = ch_find_errno(&sshdr);
 208
 209                 switch(sshdr.sense_key) {
 210                 case UNIT_ATTENTION:
 211                         ch->unit_attention = 1;
 212                         if (retries++ < 3)
 213                                 goto retry;
 214                         break;
 215                 }
 216         }
 217         return errno;
 218 }
 219
 220 /* ------------------------------------------------------------------------ */
 221
 222 static int
 223 ch_elem_to_typecode(scsi_changer *ch, u_int elem)
 224 {
 225         int i;
 226
 227         for (i = 0; i < CH_TYPES; i++) {
 228                 if (elem >= ch->firsts[i]  &&
 229                     elem <  ch->firsts[i] +
 230                     ch->counts[i])
 231                         return i+1;
 232         }
 233         return 0;
 234 }
 235
 236 static int
 237 ch_read_element_status(scsi_changer *ch, u_int elem, char *data)
 238 {
 239         u_char  cmd[12];
 240         u_char  *buffer;
 241         int     result;
 242
 243         buffer = kmalloc(512, GFP_KERNEL);
 244         if(!buffer)
 245                 return -ENOMEM;
 246
 247  retry:
 248         memset(cmd,0,sizeof(cmd));
 249         cmd[0] = READ_ELEMENT_STATUS;
 250         cmd[1] = ((ch->device->lun & 0x7) << 5) |
 251                 (ch->voltags ? 0x10 : 0) |
 252                 ch_elem_to_typecode(ch,elem);
 253         cmd[2] = (elem >> 8) & 0xff;
 254         cmd[3] = elem        & 0xff;
 255         cmd[5] = 1;
 256         cmd[9] = 255;
 257         if (0 == (result = ch_do_scsi(ch, cmd, 12,
 258                                       buffer, 256, REQ_OP_DRV_IN))) {
 259                 if (((buffer[16] << 8) | buffer[17]) != elem) {
 260                         DPRINTK("asked for element 0x%02x, got 0x%02x\n",
 261                                 elem,(buffer[16] << 8) | buffer[17]);
 262                         kfree(buffer);
 263                         return -EIO;
 264                 }
 265                 memcpy(data,buffer+16,16);
 266         } else {
 267                 if (ch->voltags) {
 268                         ch->voltags = 0;
 269                         VPRINTK(KERN_INFO, "device has no volume tag support\n");
 270                         goto retry;
 271                 }
 272                 DPRINTK("READ ELEMENT STATUS for element 0x%x failed\n",elem);
 273         }
 274         kfree(buffer);
 275         return result;
 276 }
 277
 278 static int
 279 ch_init_elem(scsi_changer *ch)
 280 {
 281         int err;
 282         u_char cmd[6];
 283
 284         VPRINTK(KERN_INFO, "INITIALIZE ELEMENT STATUS, may take some time ...\n");
 285         memset(cmd,0,sizeof(cmd));
 286         cmd[0] = INITIALIZE_ELEMENT_STATUS;
 287         cmd[1] = (ch->device->lun & 0x7) << 5;
 288         err = ch_do_scsi(ch, cmd, 6, NULL, 0, REQ_OP_DRV_IN);
 289         VPRINTK(KERN_INFO, "... finished\n");
 290         return err;
 291 }
 292
 293 static int
 294 ch_readconfig(scsi_changer *ch)
 295 {
 296         u_char  cmd[10], data[16];
 297         u_char  *buffer;
 298         int     result,id,lun,i;
 299         u_int   elem;
 300
 301         buffer = kzalloc(512, GFP_KERNEL);
 302         if (!buffer)
 303                 return -ENOMEM;
 304
 305         memset(cmd,0,sizeof(cmd));
 306         cmd[0] = MODE_SENSE;
 307         cmd[1] = (ch->device->lun & 0x7) << 5;
 308         cmd[2] = 0x1d;
 309         cmd[4] = 255;
 310         result = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
 311         if (0 != result) {
 312                 cmd[1] |= (1<<3);
 313                 result  = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
 314         }
 315         if (0 == result) {
 316                 ch->firsts[CHET_MT] =
 317                         (buffer[buffer[3]+ 6] << 8) | buffer[buffer[3]+ 7];
 318                 ch->counts[CHET_MT] =
 319                         (buffer[buffer[3]+ 8] << 8) | buffer[buffer[3]+ 9];
 320                 ch->firsts[CHET_ST] =
 321                         (buffer[buffer[3]+10] << 8) | buffer[buffer[3]+11];
 322                 ch->counts[CHET_ST] =
 323                         (buffer[buffer[3]+12] << 8) | buffer[buffer[3]+13];
 324                 ch->firsts[CHET_IE] =
 325                         (buffer[buffer[3]+14] << 8) | buffer[buffer[3]+15];
 326                 ch->counts[CHET_IE] =
 327                         (buffer[buffer[3]+16] << 8) | buffer[buffer[3]+17];
 328                 ch->firsts[CHET_DT] =
 329                         (buffer[buffer[3]+18] << 8) | buffer[buffer[3]+19];
 330                 ch->counts[CHET_DT] =
 331                         (buffer[buffer[3]+20] << 8) | buffer[buffer[3]+21];
 332                 VPRINTK(KERN_INFO, "type #1 (mt): 0x%x+%d [medium transport]\n",
 333                         ch->firsts[CHET_MT],
 334                         ch->counts[CHET_MT]);
 335                 VPRINTK(KERN_INFO, "type #2 (st): 0x%x+%d [storage]\n",
 336                         ch->firsts[CHET_ST],
 337                         ch->counts[CHET_ST]);
 338                 VPRINTK(KERN_INFO, "type #3 (ie): 0x%x+%d [import/export]\n",
 339                         ch->firsts[CHET_IE],
 340                         ch->counts[CHET_IE]);
 341                 VPRINTK(KERN_INFO, "type #4 (dt): 0x%x+%d [data transfer]\n",
 342                         ch->firsts[CHET_DT],
 343                         ch->counts[CHET_DT]);
 344         } else {
 345                 VPRINTK(KERN_INFO, "reading element address assignment page failed!\n");
 346         }
 347
 348         /* vendor specific element types */
 349         for (i = 0; i < 4; i++) {
 350                 if (0 == vendor_counts[i])
 351                         continue;
 352                 if (NULL == vendor_labels[i])
 353                         continue;
 354                 ch->firsts[CHET_V1+i] = vendor_firsts[i];
 355                 ch->counts[CHET_V1+i] = vendor_counts[i];
 356                 VPRINTK(KERN_INFO, "type #%d (v%d): 0x%x+%d [%s, vendor specific]\n",
 357                         i+5,i+1,vendor_firsts[i],vendor_counts[i],
 358                         vendor_labels[i]);
 359         }
 360
 361         /* look up the devices of the data transfer elements */
 362         ch->dt = kcalloc(ch->counts[CHET_DT], sizeof(*ch->dt),
 363                          GFP_KERNEL);
 364
 365         if (!ch->dt) {
 366                 kfree(buffer);
 367                 return -ENOMEM;
 368         }
 369
 370         for (elem = 0; elem < ch->counts[CHET_DT]; elem++) {
 371                 id  = -1;
 372                 lun = 0;
 373                 if (elem < CH_DT_MAX  &&  -1 != dt_id[elem]) {
 374                         id  = dt_id[elem];
 375                         lun = dt_lun[elem];
 376                         VPRINTK(KERN_INFO, "dt 0x%x: [insmod option] ",
 377                                 elem+ch->firsts[CHET_DT]);
 378                 } else if (0 != ch_read_element_status
 379                            (ch,elem+ch->firsts[CHET_DT],data)) {
 380                         VPRINTK(KERN_INFO, "dt 0x%x: READ ELEMENT STATUS failed\n",
 381                                 elem+ch->firsts[CHET_DT]);
 382                 } else {
 383                         VPRINTK(KERN_INFO, "dt 0x%x: ",elem+ch->firsts[CHET_DT]);
 384                         if (data[6] & 0x80) {
 385                                 VPRINTK(KERN_CONT, "not this SCSI bus\n");
 386                                 ch->dt[elem] = NULL;
 387                         } else if (0 == (data[6] & 0x30)) {
 388                                 VPRINTK(KERN_CONT, "ID/LUN unknown\n");
 389                                 ch->dt[elem] = NULL;
 390                         } else {
 391                                 id  = ch->device->id;
 392                                 lun = 0;
 393                                 if (data[6] & 0x20) id  = data[7];
 394                                 if (data[6] & 0x10) lun = data[6] & 7;
 395                         }
 396                 }
 397                 if (-1 != id) {
 398                         VPRINTK(KERN_CONT, "ID %i, LUN %i, ",id,lun);
 399                         ch->dt[elem] =
 400                                 scsi_device_lookup(ch->device->host,
 401                                                    ch->device->channel,
 402                                                    id,lun);
 403                         if (!ch->dt[elem]) {
 404                                 /* should not happen */
 405                                 VPRINTK(KERN_CONT, "Huh? device not found!\n");
 406                         } else {
 407                                 VPRINTK(KERN_CONT, "name: %8.8s %16.16s %4.4s\n",
 408                                         ch->dt[elem]->vendor,
 409                                         ch->dt[elem]->model,
 410                                         ch->dt[elem]->rev);
 411                         }
 412                 }
 413         }
 414         ch->voltags = 1;
 415         kfree(buffer);
 416
 417         return 0;
 418 }
 419
 420 /* ------------------------------------------------------------------------ */
 421
 422 static int
 423 ch_position(scsi_changer *ch, u_int trans, u_int elem, int rotate)
 424 {
 425         u_char  cmd[10];
 426
 427         DPRINTK("position: 0x%x\n",elem);
 428         if (0 == trans)
 429                 trans = ch->firsts[CHET_MT];
 430         memset(cmd,0,sizeof(cmd));
 431         cmd[0]  = POSITION_TO_ELEMENT;
 432         cmd[1]  = (ch->device->lun & 0x7) << 5;
 433         cmd[2]  = (trans >> 8) & 0xff;
 434         cmd[3]  =  trans       & 0xff;
 435         cmd[4]  = (elem  >> 8) & 0xff;
 436         cmd[5]  =  elem        & 0xff;
 437         cmd[8]  = rotate ? 1 : 0;
 438         return ch_do_scsi(ch, cmd, 10, NULL, 0, REQ_OP_DRV_IN);
 439 }
 440
 441 static int
 442 ch_move(scsi_changer *ch, u_int trans, u_int src, u_int dest, int rotate)
 443 {
 444         u_char  cmd[12];
 445
 446         DPRINTK("move: 0x%x => 0x%x\n",src,dest);
 447         if (0 == trans)
 448                 trans = ch->firsts[CHET_MT];
 449         memset(cmd,0,sizeof(cmd));
 450         cmd[0]  = MOVE_MEDIUM;
 451         cmd[1]  = (ch->device->lun & 0x7) << 5;
 452         cmd[2]  = (trans >> 8) & 0xff;
 453         cmd[3]  =  trans       & 0xff;
 454         cmd[4]  = (src   >> 8) & 0xff;
 455         cmd[5]  =  src         & 0xff;
 456         cmd[6]  = (dest  >> 8) & 0xff;
 457         cmd[7]  =  dest        & 0xff;
 458         cmd[10] = rotate ? 1 : 0;
 459         return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
 460 }
 461
 462 static int
 463 ch_exchange(scsi_changer *ch, u_int trans, u_int src,
 464             u_int dest1, u_int dest2, int rotate1, int rotate2)
 465 {
 466         u_char  cmd[12];
 467
 468         DPRINTK("exchange: 0x%x => 0x%x => 0x%x\n",
 469                 src,dest1,dest2);
 470         if (0 == trans)
 471                 trans = ch->firsts[CHET_MT];
 472         memset(cmd,0,sizeof(cmd));
 473         cmd[0]  = EXCHANGE_MEDIUM;
 474         cmd[1]  = (ch->device->lun & 0x7) << 5;
 475         cmd[2]  = (trans >> 8) & 0xff;
 476         cmd[3]  =  trans       & 0xff;
 477         cmd[4]  = (src   >> 8) & 0xff;
 478         cmd[5]  =  src         & 0xff;
 479         cmd[6]  = (dest1 >> 8) & 0xff;
 480         cmd[7]  =  dest1       & 0xff;
 481         cmd[8]  = (dest2 >> 8) & 0xff;
 482         cmd[9]  =  dest2       & 0xff;
 483         cmd[10] = (rotate1 ? 1 : 0) | (rotate2 ? 2 : 0);
 484
 485         return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
 486 }
 487
 488 static void
 489 ch_check_voltag(char *tag)
 490 {
 491         int i;
 492
 493         for (i = 0; i < 32; i++) {
 494                 /* restrict to ascii */
 495                 if (tag[i] >= 0x7f || tag[i] < 0x20)
 496                         tag[i] = ' ';
 497                 /* don't allow search wildcards */
 498                 if (tag[i] == '?' ||
 499                     tag[i] == '*')
 500                         tag[i] = ' ';
 501         }
 502 }
 503
 504 static int
 505 ch_set_voltag(scsi_changer *ch, u_int elem,
 506               int alternate, int clear, u_char *tag)
 507 {
 508         u_char  cmd[12];
 509         u_char  *buffer;
 510         int result;
 511
 512         buffer = kzalloc(512, GFP_KERNEL);
 513         if (!buffer)
 514                 return -ENOMEM;
 515
 516         DPRINTK("%s %s voltag: 0x%x => \"%s\"\n",
 517                 clear     ? "clear"     : "set",
 518                 alternate ? "alternate" : "primary",
 519                 elem, tag);
 520         memset(cmd,0,sizeof(cmd));
 521         cmd[0]  = SEND_VOLUME_TAG;
 522         cmd[1] = ((ch->device->lun & 0x7) << 5) |
 523                 ch_elem_to_typecode(ch,elem);
 524         cmd[2] = (elem >> 8) & 0xff;
 525         cmd[3] = elem        & 0xff;
 526         cmd[5] = clear
 527                 ? (alternate ? 0x0d : 0x0c)
 528                 : (alternate ? 0x0b : 0x0a);
 529
 530         cmd[9] = 255;
 531
 532         memcpy(buffer,tag,32);
 533         ch_check_voltag(buffer);
 534
 535         result = ch_do_scsi(ch, cmd, 12, buffer, 256, REQ_OP_DRV_OUT);
 536         kfree(buffer);
 537         return result;
 538 }
 539
 540 static int ch_gstatus(scsi_changer *ch, int type, unsigned char __user *dest)
 541 {
 542         int retval = 0;
 543         u_char data[16];
 544         unsigned int i;
 545
 546         mutex_lock(&ch->lock);
 547         for (i = 0; i < ch->counts[type]; i++) {
 548                 if (0 != ch_read_element_status
 549                     (ch, ch->firsts[type]+i,data)) {
 550                         retval = -EIO;
 551                         break;
 552                 }
 553                 put_user(data[2], dest+i);
 554                 if (data[2] & CESTATUS_EXCEPT)
 555                         VPRINTK(KERN_INFO, "element 0x%x: asc=0x%x, ascq=0x%x\n",
 556                                 ch->firsts[type]+i,
 557                                 (int)data[4],(int)data[5]);
 558                 retval = ch_read_element_status
 559                         (ch, ch->firsts[type]+i,data);
 560                 if (0 != retval)
 561                         break;
 562         }
 563         mutex_unlock(&ch->lock);
 564         return retval;
 565 }
 566
 567 /* ------------------------------------------------------------------------ */
 568
 569 static void ch_destroy(struct kref *ref)
 570 {
 571         scsi_changer *ch = container_of(ref, scsi_changer, ref);
 572
 573         ch->device = NULL;
 574         kfree(ch->dt);
 575         kfree(ch);
 576 }
 577
 578 static int
 579 ch_release(struct inode *inode, struct file *file)
 580 {
 581         scsi_changer *ch = file->private_data;
 582
 583         scsi_device_put(ch->device);
 584         file->private_data = NULL;
 585         kref_put(&ch->ref, ch_destroy);
 586         return 0;
 587 }
 588
 589 static int
 590 ch_open(struct inode *inode, struct file *file)
 591 {
 592         scsi_changer *ch;
 593         int minor = iminor(inode);
 594
 595         spin_lock(&ch_index_lock);
 596         ch = idr_find(&ch_index_idr, minor);
 597
 598         if (ch == NULL || !kref_get_unless_zero(&ch->ref)) {
 599                 spin_unlock(&ch_index_lock);
 600                 return -ENXIO;
 601         }
 602         spin_unlock(&ch_index_lock);
 603         if (scsi_device_get(ch->device)) {
 604                 kref_put(&ch->ref, ch_destroy);
 605                 return -ENXIO;
 606         }
 607         /* Synchronize with ch_probe() */
 608         mutex_lock(&ch->lock);
 609         file->private_data = ch;
 610         mutex_unlock(&ch->lock);
 611         return 0;
 612 }
 613
 614 static int
 615 ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
 616 {
 617         if (type >= CH_TYPES  ||  unit >= ch->counts[type])
 618                 return -1;
 619         return 0;
 620 }
 621
 622 struct changer_element_status32 {
 623         int             ces_type;
 624         compat_uptr_t   ces_data;
 625 };
 626 #define CHIOGSTATUS32  _IOW('c', 8, struct changer_element_status32)
 627
 628 static long ch_ioctl(struct file *file,
 629                     unsigned int cmd, unsigned long arg)
 630 {
 631         scsi_changer *ch = file->private_data;
 632         int retval;
 633         void __user *argp = (void __user *)arg;
 634
 635         retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
 636                         file->f_flags & O_NDELAY);
 637         if (retval)
 638                 return retval;
 639
 640         switch (cmd) {
 641         case CHIOGPARAMS:
 642         {
 643                 struct changer_params params;
 644
 645                 params.cp_curpicker = 0;
 646                 params.cp_npickers  = ch->counts[CHET_MT];
 647                 params.cp_nslots    = ch->counts[CHET_ST];
 648                 params.cp_nportals  = ch->counts[CHET_IE];
 649                 params.cp_ndrives   = ch->counts[CHET_DT];
 650
 651                 if (copy_to_user(argp, &params, sizeof(params)))
 652                         return -EFAULT;
 653                 return 0;
 654         }
 655         case CHIOGVPARAMS:
 656         {
 657                 struct changer_vendor_params vparams;
 658
 659                 memset(&vparams,0,sizeof(vparams));
 660                 if (ch->counts[CHET_V1]) {
 661                         vparams.cvp_n1  = ch->counts[CHET_V1];
 662                         strncpy(vparams.cvp_label1,vendor_labels[0],16);
 663                 }
 664                 if (ch->counts[CHET_V2]) {
 665                         vparams.cvp_n2  = ch->counts[CHET_V2];
 666                         strncpy(vparams.cvp_label2,vendor_labels[1],16);
 667                 }
 668                 if (ch->counts[CHET_V3]) {
 669                         vparams.cvp_n3  = ch->counts[CHET_V3];
 670                         strncpy(vparams.cvp_label3,vendor_labels[2],16);
 671                 }
 672                 if (ch->counts[CHET_V4]) {
 673                         vparams.cvp_n4  = ch->counts[CHET_V4];
 674                         strncpy(vparams.cvp_label4,vendor_labels[3],16);
 675                 }
 676                 if (copy_to_user(argp, &vparams, sizeof(vparams)))
 677                         return -EFAULT;
 678                 return 0;
 679         }
 680
 681         case CHIOPOSITION:
 682         {
 683                 struct changer_position pos;
 684
 685                 if (copy_from_user(&pos, argp, sizeof (pos)))
 686                         return -EFAULT;
 687
 688                 if (0 != ch_checkrange(ch, pos.cp_type, pos.cp_unit)) {
 689                         DPRINTK("CHIOPOSITION: invalid parameter\n");
 690                         return -EBADSLT;
 691                 }
 692                 mutex_lock(&ch->lock);
 693                 retval = ch_position(ch,0,
 694                                      ch->firsts[pos.cp_type] + pos.cp_unit,
 695                                      pos.cp_flags & CP_INVERT);
 696                 mutex_unlock(&ch->lock);
 697                 return retval;
 698         }
 699
 700         case CHIOMOVE:
 701         {
 702                 struct changer_move mv;
 703
 704                 if (copy_from_user(&mv, argp, sizeof (mv)))
 705                         return -EFAULT;
 706
 707                 if (0 != ch_checkrange(ch, mv.cm_fromtype, mv.cm_fromunit) ||
 708                     0 != ch_checkrange(ch, mv.cm_totype,   mv.cm_tounit  )) {
 709                         DPRINTK("CHIOMOVE: invalid parameter\n");
 710                         return -EBADSLT;
 711                 }
 712
 713                 mutex_lock(&ch->lock);
 714                 retval = ch_move(ch,0,
 715                                  ch->firsts[mv.cm_fromtype] + mv.cm_fromunit,
 716                                  ch->firsts[mv.cm_totype]   + mv.cm_tounit,
 717                                  mv.cm_flags & CM_INVERT);
 718                 mutex_unlock(&ch->lock);
 719                 return retval;
 720         }
 721
 722         case CHIOEXCHANGE:
 723         {
 724                 struct changer_exchange mv;
 725
 726                 if (copy_from_user(&mv, argp, sizeof (mv)))
 727                         return -EFAULT;
 728
 729                 if (0 != ch_checkrange(ch, mv.ce_srctype,  mv.ce_srcunit ) ||
 730                     0 != ch_checkrange(ch, mv.ce_fdsttype, mv.ce_fdstunit) ||
 731                     0 != ch_checkrange(ch, mv.ce_sdsttype, mv.ce_sdstunit)) {
 732                         DPRINTK("CHIOEXCHANGE: invalid parameter\n");
 733                         return -EBADSLT;
 734                 }
 735
 736                 mutex_lock(&ch->lock);
 737                 retval = ch_exchange
 738                         (ch,0,
 739                          ch->firsts[mv.ce_srctype]  + mv.ce_srcunit,
 740                          ch->firsts[mv.ce_fdsttype] + mv.ce_fdstunit,
 741                          ch->firsts[mv.ce_sdsttype] + mv.ce_sdstunit,
 742                          mv.ce_flags & CE_INVERT1, mv.ce_flags & CE_INVERT2);
 743                 mutex_unlock(&ch->lock);
 744                 return retval;
 745         }
 746
 747         case CHIOGSTATUS:
 748         {
 749                 struct changer_element_status ces;
 750
 751                 if (copy_from_user(&ces, argp, sizeof (ces)))
 752                         return -EFAULT;
 753                 if (ces.ces_type < 0 || ces.ces_type >= CH_TYPES)
 754                         return -EINVAL;
 755
 756                 return ch_gstatus(ch, ces.ces_type, ces.ces_data);
 757         }
 758 #ifdef CONFIG_COMPAT
 759         case CHIOGSTATUS32:
 760         {
 761                 struct changer_element_status32 ces32;
 762
 763                 if (copy_from_user(&ces32, argp, sizeof(ces32)))
 764                         return -EFAULT;
 765                 if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
 766                         return -EINVAL;
 767
 768                 return ch_gstatus(ch, ces32.ces_type,
 769                                   compat_ptr(ces32.ces_data));
 770         }
 771 #endif
 772         case CHIOGELEM:
 773         {
 774                 struct changer_get_element cge;
 775                 u_char ch_cmd[12];
 776                 u_char *buffer;
 777                 unsigned int elem;
 778                 int     result,i;
 779
 780                 if (copy_from_user(&cge, argp, sizeof (cge)))
 781                         return -EFAULT;
 782
 783                 if (0 != ch_checkrange(ch, cge.cge_type, cge.cge_unit))
 784                         return -EINVAL;
 785                 elem = ch->firsts[cge.cge_type] + cge.cge_unit;
 786
 787                 buffer = kmalloc(512, GFP_KERNEL);
 788                 if (!buffer)
 789                         return -ENOMEM;
 790                 mutex_lock(&ch->lock);
 791
 792         voltag_retry:
 793                 memset(ch_cmd, 0, sizeof(ch_cmd));
 794                 ch_cmd[0] = READ_ELEMENT_STATUS;
 795                 ch_cmd[1] = ((ch->device->lun & 0x7) << 5) |
 796                         (ch->voltags ? 0x10 : 0) |
 797                         ch_elem_to_typecode(ch,elem);
 798                 ch_cmd[2] = (elem >> 8) & 0xff;
 799                 ch_cmd[3] = elem        & 0xff;
 800                 ch_cmd[5] = 1;
 801                 ch_cmd[9] = 255;
 802
 803                 result = ch_do_scsi(ch, ch_cmd, 12, buffer, 256, REQ_OP_DRV_IN);
 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, file->f_mode & FMODE_WRITE, cmd,
 881                                   argp);
 882
 883         }
 884 }
 885
 886 /* ------------------------------------------------------------------------ */
 887
 888 static int ch_probe(struct device *dev)
 889 {
 890         struct scsi_device *sd = to_scsi_device(dev);
 891         struct device *class_dev;
 892         int ret;
 893         scsi_changer *ch;
 894
 895         if (sd->type != TYPE_MEDIUM_CHANGER)
 896                 return -ENODEV;
 897
 898         ch = kzalloc(sizeof(*ch), GFP_KERNEL);
 899         if (NULL == ch)
 900                 return -ENOMEM;
 901
 902         idr_preload(GFP_KERNEL);
 903         spin_lock(&ch_index_lock);
 904         ret = idr_alloc(&ch_index_idr, ch, 0, CH_MAX_DEVS + 1, GFP_NOWAIT);
 905         spin_unlock(&ch_index_lock);
 906         idr_preload_end();
 907
 908         if (ret < 0) {
 909                 if (ret == -ENOSPC)
 910                         ret = -ENODEV;
 911                 goto free_ch;
 912         }
 913
 914         ch->minor = ret;
 915         sprintf(ch->name,"ch%d",ch->minor);
 916         ret = scsi_device_get(sd);
 917         if (ret) {
 918                 sdev_printk(KERN_WARNING, sd, "ch%d: failed to get device\n",
 919                             ch->minor);
 920                 goto remove_idr;
 921         }
 922
 923         mutex_init(&ch->lock);
 924         kref_init(&ch->ref);
 925         ch->device = sd;
 926         class_dev = device_create(ch_sysfs_class, dev,
 927                                   MKDEV(SCSI_CHANGER_MAJOR, ch->minor), ch,
 928                                   "s%s", ch->name);
 929         if (IS_ERR(class_dev)) {
 930                 sdev_printk(KERN_WARNING, sd, "ch%d: device_create failed\n",
 931                             ch->minor);
 932                 ret = PTR_ERR(class_dev);
 933                 goto put_device;
 934         }
 935
 936         mutex_lock(&ch->lock);
 937         ret = ch_readconfig(ch);
 938         if (ret) {
 939                 mutex_unlock(&ch->lock);
 940                 goto destroy_dev;
 941         }
 942         if (init)
 943                 ch_init_elem(ch);
 944
 945         mutex_unlock(&ch->lock);
 946         dev_set_drvdata(dev, ch);
 947         sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
 948
 949         return 0;
 950 destroy_dev:
 951         device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
 952 put_device:
 953         scsi_device_put(sd);
 954 remove_idr:
 955         idr_remove(&ch_index_idr, ch->minor);
 956 free_ch:
 957         kfree(ch);
 958         return ret;
 959 }
 960
 961 static int ch_remove(struct device *dev)
 962 {
 963         scsi_changer *ch = dev_get_drvdata(dev);
 964
 965         spin_lock(&ch_index_lock);
 966         idr_remove(&ch_index_idr, ch->minor);
 967         dev_set_drvdata(dev, NULL);
 968         spin_unlock(&ch_index_lock);
 969
 970         device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR,ch->minor));
 971         scsi_device_put(ch->device);
 972         kref_put(&ch->ref, ch_destroy);
 973         return 0;
 974 }
 975
 976 static struct scsi_driver ch_template = {
 977         .gendrv         = {
 978                 .name   = "ch",
 979                 .owner  = THIS_MODULE,
 980                 .probe  = ch_probe,
 981                 .remove = ch_remove,
 982         },
 983 };
 984
 985 static const struct file_operations changer_fops = {
 986         .owner          = THIS_MODULE,
 987         .open           = ch_open,
 988         .release        = ch_release,
 989         .unlocked_ioctl = ch_ioctl,
 990         .compat_ioctl   = compat_ptr_ioctl,
 991         .llseek         = noop_llseek,
 992 };
 993
 994 static int __init init_ch_module(void)
 995 {
 996         int rc;
 997
 998         printk(KERN_INFO "SCSI Media Changer driver v" VERSION " \n");
 999         ch_sysfs_class = class_create("scsi_changer");
1000         if (IS_ERR(ch_sysfs_class)) {
1001                 rc = PTR_ERR(ch_sysfs_class);
1002                 return rc;
1003         }
1004         rc = register_chrdev(SCSI_CHANGER_MAJOR,"ch",&changer_fops);
1005         if (rc < 0) {
1006                 printk("Unable to get major %d for SCSI-Changer\n",
1007                        SCSI_CHANGER_MAJOR);
1008                 goto fail1;
1009         }
1010         rc = scsi_register_driver(&ch_template.gendrv);
1011         if (rc < 0)
1012                 goto fail2;
1013         return 0;
1014
1015  fail2:
1016         unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1017  fail1:
1018         class_destroy(ch_sysfs_class);
1019         return rc;
1020 }
1021
1022 static void __exit exit_ch_module(void)
1023 {
1024         scsi_unregister_driver(&ch_template.gendrv);
1025         unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1026         class_destroy(ch_sysfs_class);
1027         idr_destroy(&ch_index_idr);
1028 }
1029
1030 module_init(init_ch_module);
1031 module_exit(exit_ch_module);