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
 202         if (driver_byte(result) == DRIVER_SENSE) {
 203                 if (debug)
 204                         scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
 205                 errno = ch_find_errno(&sshdr);
 206
 207                 switch(sshdr.sense_key) {
 208                 case UNIT_ATTENTION:
 209                         ch->unit_attention = 1;
 210                         if (retries++ < 3)
 211                                 goto retry;
 212                         break;
 213                 }
 214         }
 215         return errno;
 216 }
 217
 218 /* ------------------------------------------------------------------------ */
 219
 220 static int
 221 ch_elem_to_typecode(scsi_changer *ch, u_int elem)
 222 {
 223         int i;
 224
 225         for (i = 0; i < CH_TYPES; i++) {
 226                 if (elem >= ch->firsts[i]  &&
 227                     elem <  ch->firsts[i] +
 228                     ch->counts[i])
 229                         return i+1;
 230         }
 231         return 0;
 232 }
 233
 234 static int
 235 ch_read_element_status(scsi_changer *ch, u_int elem, char *data)
 236 {
 237         u_char  cmd[12];
 238         u_char  *buffer;
 239         int     result;
 240
 241         buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
 242         if(!buffer)
 243                 return -ENOMEM;
 244
 245  retry:
 246         memset(cmd,0,sizeof(cmd));
 247         cmd[0] = READ_ELEMENT_STATUS;
 248         cmd[1] = ((ch->device->lun & 0x7) << 5) |
 249                 (ch->voltags ? 0x10 : 0) |
 250                 ch_elem_to_typecode(ch,elem);
 251         cmd[2] = (elem >> 8) & 0xff;
 252         cmd[3] = elem        & 0xff;
 253         cmd[5] = 1;
 254         cmd[9] = 255;
 255         if (0 == (result = ch_do_scsi(ch, cmd, 12,
 256                                       buffer, 256, DMA_FROM_DEVICE))) {
 257                 if (((buffer[16] << 8) | buffer[17]) != elem) {
 258                         DPRINTK("asked for element 0x%02x, got 0x%02x\n",
 259                                 elem,(buffer[16] << 8) | buffer[17]);
 260                         kfree(buffer);
 261                         return -EIO;
 262                 }
 263                 memcpy(data,buffer+16,16);
 264         } else {
 265                 if (ch->voltags) {
 266                         ch->voltags = 0;
 267                         VPRINTK(KERN_INFO, "device has no volume tag support\n");
 268                         goto retry;
 269                 }
 270                 DPRINTK("READ ELEMENT STATUS for element 0x%x failed\n",elem);
 271         }
 272         kfree(buffer);
 273         return result;
 274 }
 275
 276 static int
 277 ch_init_elem(scsi_changer *ch)
 278 {
 279         int err;
 280         u_char cmd[6];
 281
 282         VPRINTK(KERN_INFO, "INITIALIZE ELEMENT STATUS, may take some time ...\n");
 283         memset(cmd,0,sizeof(cmd));
 284         cmd[0] = INITIALIZE_ELEMENT_STATUS;
 285         cmd[1] = (ch->device->lun & 0x7) << 5;
 286         err = ch_do_scsi(ch, cmd, 6, NULL, 0, DMA_NONE);
 287         VPRINTK(KERN_INFO, "... finished\n");
 288         return err;
 289 }
 290
 291 static int
 292 ch_readconfig(scsi_changer *ch)
 293 {
 294         u_char  cmd[10], data[16];
 295         u_char  *buffer;
 296         int     result,id,lun,i;
 297         u_int   elem;
 298
 299         buffer = kzalloc(512, GFP_KERNEL | GFP_DMA);
 300         if (!buffer)
 301                 return -ENOMEM;
 302
 303         memset(cmd,0,sizeof(cmd));
 304         cmd[0] = MODE_SENSE;
 305         cmd[1] = (ch->device->lun & 0x7) << 5;
 306         cmd[2] = 0x1d;
 307         cmd[4] = 255;
 308         result = ch_do_scsi(ch, cmd, 10, buffer, 255, DMA_FROM_DEVICE);
 309         if (0 != result) {
 310                 cmd[1] |= (1<<3);
 311                 result  = ch_do_scsi(ch, cmd, 10, buffer, 255, DMA_FROM_DEVICE);
 312         }
 313         if (0 == result) {
 314                 ch->firsts[CHET_MT] =
 315                         (buffer[buffer[3]+ 6] << 8) | buffer[buffer[3]+ 7];
 316                 ch->counts[CHET_MT] =
 317                         (buffer[buffer[3]+ 8] << 8) | buffer[buffer[3]+ 9];
 318                 ch->firsts[CHET_ST] =
 319                         (buffer[buffer[3]+10] << 8) | buffer[buffer[3]+11];
 320                 ch->counts[CHET_ST] =
 321                         (buffer[buffer[3]+12] << 8) | buffer[buffer[3]+13];
 322                 ch->firsts[CHET_IE] =
 323                         (buffer[buffer[3]+14] << 8) | buffer[buffer[3]+15];
 324                 ch->counts[CHET_IE] =
 325                         (buffer[buffer[3]+16] << 8) | buffer[buffer[3]+17];
 326                 ch->firsts[CHET_DT] =
 327                         (buffer[buffer[3]+18] << 8) | buffer[buffer[3]+19];
 328                 ch->counts[CHET_DT] =
 329                         (buffer[buffer[3]+20] << 8) | buffer[buffer[3]+21];
 330                 VPRINTK(KERN_INFO, "type #1 (mt): 0x%x+%d [medium transport]\n",
 331                         ch->firsts[CHET_MT],
 332                         ch->counts[CHET_MT]);
 333                 VPRINTK(KERN_INFO, "type #2 (st): 0x%x+%d [storage]\n",
 334                         ch->firsts[CHET_ST],
 335                         ch->counts[CHET_ST]);
 336                 VPRINTK(KERN_INFO, "type #3 (ie): 0x%x+%d [import/export]\n",
 337                         ch->firsts[CHET_IE],
 338                         ch->counts[CHET_IE]);
 339                 VPRINTK(KERN_INFO, "type #4 (dt): 0x%x+%d [data transfer]\n",
 340                         ch->firsts[CHET_DT],
 341                         ch->counts[CHET_DT]);
 342         } else {
 343                 VPRINTK(KERN_INFO, "reading element address assignment page failed!\n");
 344         }
 345
 346         /* vendor specific element types */
 347         for (i = 0; i < 4; i++) {
 348                 if (0 == vendor_counts[i])
 349                         continue;
 350                 if (NULL == vendor_labels[i])
 351                         continue;
 352                 ch->firsts[CHET_V1+i] = vendor_firsts[i];
 353                 ch->counts[CHET_V1+i] = vendor_counts[i];
 354                 VPRINTK(KERN_INFO, "type #%d (v%d): 0x%x+%d [%s, vendor specific]\n",
 355                         i+5,i+1,vendor_firsts[i],vendor_counts[i],
 356                         vendor_labels[i]);
 357         }
 358
 359         /* look up the devices of the data transfer elements */
 360         ch->dt = kcalloc(ch->counts[CHET_DT], sizeof(*ch->dt),
 361                          GFP_KERNEL);
 362
 363         if (!ch->dt) {
 364                 kfree(buffer);
 365                 return -ENOMEM;
 366         }
 367
 368         for (elem = 0; elem < ch->counts[CHET_DT]; elem++) {
 369                 id  = -1;
 370                 lun = 0;
 371                 if (elem < CH_DT_MAX  &&  -1 != dt_id[elem]) {
 372                         id  = dt_id[elem];
 373                         lun = dt_lun[elem];
 374                         VPRINTK(KERN_INFO, "dt 0x%x: [insmod option] ",
 375                                 elem+ch->firsts[CHET_DT]);
 376                 } else if (0 != ch_read_element_status
 377                            (ch,elem+ch->firsts[CHET_DT],data)) {
 378                         VPRINTK(KERN_INFO, "dt 0x%x: READ ELEMENT STATUS failed\n",
 379                                 elem+ch->firsts[CHET_DT]);
 380                 } else {
 381                         VPRINTK(KERN_INFO, "dt 0x%x: ",elem+ch->firsts[CHET_DT]);
 382                         if (data[6] & 0x80) {
 383                                 VPRINTK(KERN_CONT, "not this SCSI bus\n");
 384                                 ch->dt[elem] = NULL;
 385                         } else if (0 == (data[6] & 0x30)) {
 386                                 VPRINTK(KERN_CONT, "ID/LUN unknown\n");
 387                                 ch->dt[elem] = NULL;
 388                         } else {
 389                                 id  = ch->device->id;
 390                                 lun = 0;
 391                                 if (data[6] & 0x20) id  = data[7];
 392                                 if (data[6] & 0x10) lun = data[6] & 7;
 393                         }
 394                 }
 395                 if (-1 != id) {
 396                         VPRINTK(KERN_CONT, "ID %i, LUN %i, ",id,lun);
 397                         ch->dt[elem] =
 398                                 scsi_device_lookup(ch->device->host,
 399                                                    ch->device->channel,
 400                                                    id,lun);
 401                         if (!ch->dt[elem]) {
 402                                 /* should not happen */
 403                                 VPRINTK(KERN_CONT, "Huh? device not found!\n");
 404                         } else {
 405                                 VPRINTK(KERN_CONT, "name: %8.8s %16.16s %4.4s\n",
 406                                         ch->dt[elem]->vendor,
 407                                         ch->dt[elem]->model,
 408                                         ch->dt[elem]->rev);
 409                         }
 410                 }
 411         }
 412         ch->voltags = 1;
 413         kfree(buffer);
 414
 415         return 0;
 416 }
 417
 418 /* ------------------------------------------------------------------------ */
 419
 420 static int
 421 ch_position(scsi_changer *ch, u_int trans, u_int elem, int rotate)
 422 {
 423         u_char  cmd[10];
 424
 425         DPRINTK("position: 0x%x\n",elem);
 426         if (0 == trans)
 427                 trans = ch->firsts[CHET_MT];
 428         memset(cmd,0,sizeof(cmd));
 429         cmd[0]  = POSITION_TO_ELEMENT;
 430         cmd[1]  = (ch->device->lun & 0x7) << 5;
 431         cmd[2]  = (trans >> 8) & 0xff;
 432         cmd[3]  =  trans       & 0xff;
 433         cmd[4]  = (elem  >> 8) & 0xff;
 434         cmd[5]  =  elem        & 0xff;
 435         cmd[8]  = rotate ? 1 : 0;
 436         return ch_do_scsi(ch, cmd, 10, NULL, 0, DMA_NONE);
 437 }
 438
 439 static int
 440 ch_move(scsi_changer *ch, u_int trans, u_int src, u_int dest, int rotate)
 441 {
 442         u_char  cmd[12];
 443
 444         DPRINTK("move: 0x%x => 0x%x\n",src,dest);
 445         if (0 == trans)
 446                 trans = ch->firsts[CHET_MT];
 447         memset(cmd,0,sizeof(cmd));
 448         cmd[0]  = MOVE_MEDIUM;
 449         cmd[1]  = (ch->device->lun & 0x7) << 5;
 450         cmd[2]  = (trans >> 8) & 0xff;
 451         cmd[3]  =  trans       & 0xff;
 452         cmd[4]  = (src   >> 8) & 0xff;
 453         cmd[5]  =  src         & 0xff;
 454         cmd[6]  = (dest  >> 8) & 0xff;
 455         cmd[7]  =  dest        & 0xff;
 456         cmd[10] = rotate ? 1 : 0;
 457         return ch_do_scsi(ch, cmd, 12, NULL,0, DMA_NONE);
 458 }
 459
 460 static int
 461 ch_exchange(scsi_changer *ch, u_int trans, u_int src,
 462             u_int dest1, u_int dest2, int rotate1, int rotate2)
 463 {
 464         u_char  cmd[12];
 465
 466         DPRINTK("exchange: 0x%x => 0x%x => 0x%x\n",
 467                 src,dest1,dest2);
 468         if (0 == trans)
 469                 trans = ch->firsts[CHET_MT];
 470         memset(cmd,0,sizeof(cmd));
 471         cmd[0]  = EXCHANGE_MEDIUM;
 472         cmd[1]  = (ch->device->lun & 0x7) << 5;
 473         cmd[2]  = (trans >> 8) & 0xff;
 474         cmd[3]  =  trans       & 0xff;
 475         cmd[4]  = (src   >> 8) & 0xff;
 476         cmd[5]  =  src         & 0xff;
 477         cmd[6]  = (dest1 >> 8) & 0xff;
 478         cmd[7]  =  dest1       & 0xff;
 479         cmd[8]  = (dest2 >> 8) & 0xff;
 480         cmd[9]  =  dest2       & 0xff;
 481         cmd[10] = (rotate1 ? 1 : 0) | (rotate2 ? 2 : 0);
 482
 483         return ch_do_scsi(ch, cmd, 12, NULL, 0, DMA_NONE);
 484 }
 485
 486 static void
 487 ch_check_voltag(char *tag)
 488 {
 489         int i;
 490
 491         for (i = 0; i < 32; i++) {
 492                 /* restrict to ascii */
 493                 if (tag[i] >= 0x7f || tag[i] < 0x20)
 494                         tag[i] = ' ';
 495                 /* don't allow search wildcards */
 496                 if (tag[i] == '?' ||
 497                     tag[i] == '*')
 498                         tag[i] = ' ';
 499         }
 500 }
 501
 502 static int
 503 ch_set_voltag(scsi_changer *ch, u_int elem,
 504               int alternate, int clear, u_char *tag)
 505 {
 506         u_char  cmd[12];
 507         u_char  *buffer;
 508         int result;
 509
 510         buffer = kzalloc(512, GFP_KERNEL);
 511         if (!buffer)
 512                 return -ENOMEM;
 513
 514         DPRINTK("%s %s voltag: 0x%x => \"%s\"\n",
 515                 clear     ? "clear"     : "set",
 516                 alternate ? "alternate" : "primary",
 517                 elem, tag);
 518         memset(cmd,0,sizeof(cmd));
 519         cmd[0]  = SEND_VOLUME_TAG;
 520         cmd[1] = ((ch->device->lun & 0x7) << 5) |
 521                 ch_elem_to_typecode(ch,elem);
 522         cmd[2] = (elem >> 8) & 0xff;
 523         cmd[3] = elem        & 0xff;
 524         cmd[5] = clear
 525                 ? (alternate ? 0x0d : 0x0c)
 526                 : (alternate ? 0x0b : 0x0a);
 527
 528         cmd[9] = 255;
 529
 530         memcpy(buffer,tag,32);
 531         ch_check_voltag(buffer);
 532
 533         result = ch_do_scsi(ch, cmd, 12, buffer, 256, DMA_TO_DEVICE);
 534         kfree(buffer);
 535         return result;
 536 }
 537
 538 static int ch_gstatus(scsi_changer *ch, int type, unsigned char __user *dest)
 539 {
 540         int retval = 0;
 541         u_char data[16];
 542         unsigned int i;
 543
 544         mutex_lock(&ch->lock);
 545         for (i = 0; i < ch->counts[type]; i++) {
 546                 if (0 != ch_read_element_status
 547                     (ch, ch->firsts[type]+i,data)) {
 548                         retval = -EIO;
 549                         break;
 550                 }
 551                 put_user(data[2], dest+i);
 552                 if (data[2] & CESTATUS_EXCEPT)
 553                         VPRINTK(KERN_INFO, "element 0x%x: asc=0x%x, ascq=0x%x\n",
 554                                 ch->firsts[type]+i,
 555                                 (int)data[4],(int)data[5]);
 556                 retval = ch_read_element_status
 557                         (ch, ch->firsts[type]+i,data);
 558                 if (0 != retval)
 559                         break;
 560         }
 561         mutex_unlock(&ch->lock);
 562         return retval;
 563 }
 564
 565 /* ------------------------------------------------------------------------ */
 566
 567 static void ch_destroy(struct kref *ref)
 568 {
 569         scsi_changer *ch = container_of(ref, scsi_changer, ref);
 570
 571         ch->device = NULL;
 572         kfree(ch->dt);
 573         kfree(ch);
 574 }
 575
 576 static int
 577 ch_release(struct inode *inode, struct file *file)
 578 {
 579         scsi_changer *ch = file->private_data;
 580
 581         scsi_device_put(ch->device);
 582         file->private_data = NULL;
 583         kref_put(&ch->ref, ch_destroy);
 584         return 0;
 585 }
 586
 587 static int
 588 ch_open(struct inode *inode, struct file *file)
 589 {
 590         scsi_changer *ch;
 591         int minor = iminor(inode);
 592
 593         spin_lock(&ch_index_lock);
 594         ch = idr_find(&ch_index_idr, minor);
 595
 596         if (ch == NULL || !kref_get_unless_zero(&ch->ref)) {
 597                 spin_unlock(&ch_index_lock);
 598                 return -ENXIO;
 599         }
 600         spin_unlock(&ch_index_lock);
 601         if (scsi_device_get(ch->device)) {
 602                 kref_put(&ch->ref, ch_destroy);
 603                 return -ENXIO;
 604         }
 605         /* Synchronize with ch_probe() */
 606         mutex_lock(&ch->lock);
 607         file->private_data = ch;
 608         mutex_unlock(&ch->lock);
 609         return 0;
 610 }
 611
 612 static int
 613 ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
 614 {
 615         if (type >= CH_TYPES  ||  unit >= ch->counts[type])
 616                 return -1;
 617         return 0;
 618 }
 619
 620 static long ch_ioctl(struct file *file,
 621                     unsigned int cmd, unsigned long arg)
 622 {
 623         scsi_changer *ch = file->private_data;
 624         int retval;
 625         void __user *argp = (void __user *)arg;
 626
 627         retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
 628                         file->f_flags & O_NDELAY);
 629         if (retval)
 630                 return retval;
 631
 632         switch (cmd) {
 633         case CHIOGPARAMS:
 634         {
 635                 struct changer_params params;
 636
 637                 params.cp_curpicker = 0;
 638                 params.cp_npickers  = ch->counts[CHET_MT];
 639                 params.cp_nslots    = ch->counts[CHET_ST];
 640                 params.cp_nportals  = ch->counts[CHET_IE];
 641                 params.cp_ndrives   = ch->counts[CHET_DT];
 642
 643                 if (copy_to_user(argp, &params, sizeof(params)))
 644                         return -EFAULT;
 645                 return 0;
 646         }
 647         case CHIOGVPARAMS:
 648         {
 649                 struct changer_vendor_params vparams;
 650
 651                 memset(&vparams,0,sizeof(vparams));
 652                 if (ch->counts[CHET_V1]) {
 653                         vparams.cvp_n1  = ch->counts[CHET_V1];
 654                         strncpy(vparams.cvp_label1,vendor_labels[0],16);
 655                 }
 656                 if (ch->counts[CHET_V2]) {
 657                         vparams.cvp_n2  = ch->counts[CHET_V2];
 658                         strncpy(vparams.cvp_label2,vendor_labels[1],16);
 659                 }
 660                 if (ch->counts[CHET_V3]) {
 661                         vparams.cvp_n3  = ch->counts[CHET_V3];
 662                         strncpy(vparams.cvp_label3,vendor_labels[2],16);
 663                 }
 664                 if (ch->counts[CHET_V4]) {
 665                         vparams.cvp_n4  = ch->counts[CHET_V4];
 666                         strncpy(vparams.cvp_label4,vendor_labels[3],16);
 667                 }
 668                 if (copy_to_user(argp, &vparams, sizeof(vparams)))
 669                         return -EFAULT;
 670                 return 0;
 671         }
 672
 673         case CHIOPOSITION:
 674         {
 675                 struct changer_position pos;
 676
 677                 if (copy_from_user(&pos, argp, sizeof (pos)))
 678                         return -EFAULT;
 679
 680                 if (0 != ch_checkrange(ch, pos.cp_type, pos.cp_unit)) {
 681                         DPRINTK("CHIOPOSITION: invalid parameter\n");
 682                         return -EBADSLT;
 683                 }
 684                 mutex_lock(&ch->lock);
 685                 retval = ch_position(ch,0,
 686                                      ch->firsts[pos.cp_type] + pos.cp_unit,
 687                                      pos.cp_flags & CP_INVERT);
 688                 mutex_unlock(&ch->lock);
 689                 return retval;
 690         }
 691
 692         case CHIOMOVE:
 693         {
 694                 struct changer_move mv;
 695
 696                 if (copy_from_user(&mv, argp, sizeof (mv)))
 697                         return -EFAULT;
 698
 699                 if (0 != ch_checkrange(ch, mv.cm_fromtype, mv.cm_fromunit) ||
 700                     0 != ch_checkrange(ch, mv.cm_totype,   mv.cm_tounit  )) {
 701                         DPRINTK("CHIOMOVE: invalid parameter\n");
 702                         return -EBADSLT;
 703                 }
 704
 705                 mutex_lock(&ch->lock);
 706                 retval = ch_move(ch,0,
 707                                  ch->firsts[mv.cm_fromtype] + mv.cm_fromunit,
 708                                  ch->firsts[mv.cm_totype]   + mv.cm_tounit,
 709                                  mv.cm_flags & CM_INVERT);
 710                 mutex_unlock(&ch->lock);
 711                 return retval;
 712         }
 713
 714         case CHIOEXCHANGE:
 715         {
 716                 struct changer_exchange mv;
 717
 718                 if (copy_from_user(&mv, argp, sizeof (mv)))
 719                         return -EFAULT;
 720
 721                 if (0 != ch_checkrange(ch, mv.ce_srctype,  mv.ce_srcunit ) ||
 722                     0 != ch_checkrange(ch, mv.ce_fdsttype, mv.ce_fdstunit) ||
 723                     0 != ch_checkrange(ch, mv.ce_sdsttype, mv.ce_sdstunit)) {
 724                         DPRINTK("CHIOEXCHANGE: invalid parameter\n");
 725                         return -EBADSLT;
 726                 }
 727
 728                 mutex_lock(&ch->lock);
 729                 retval = ch_exchange
 730                         (ch,0,
 731                          ch->firsts[mv.ce_srctype]  + mv.ce_srcunit,
 732                          ch->firsts[mv.ce_fdsttype] + mv.ce_fdstunit,
 733                          ch->firsts[mv.ce_sdsttype] + mv.ce_sdstunit,
 734                          mv.ce_flags & CE_INVERT1, mv.ce_flags & CE_INVERT2);
 735                 mutex_unlock(&ch->lock);
 736                 return retval;
 737         }
 738
 739         case CHIOGSTATUS:
 740         {
 741                 struct changer_element_status ces;
 742
 743                 if (copy_from_user(&ces, argp, sizeof (ces)))
 744                         return -EFAULT;
 745                 if (ces.ces_type < 0 || ces.ces_type >= CH_TYPES)
 746                         return -EINVAL;
 747
 748                 return ch_gstatus(ch, ces.ces_type, ces.ces_data);
 749         }
 750
 751         case CHIOGELEM:
 752         {
 753                 struct changer_get_element cge;
 754                 u_char ch_cmd[12];
 755                 u_char *buffer;
 756                 unsigned int elem;
 757                 int     result,i;
 758
 759                 if (copy_from_user(&cge, argp, sizeof (cge)))
 760                         return -EFAULT;
 761
 762                 if (0 != ch_checkrange(ch, cge.cge_type, cge.cge_unit))
 763                         return -EINVAL;
 764                 elem = ch->firsts[cge.cge_type] + cge.cge_unit;
 765
 766                 buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
 767                 if (!buffer)
 768                         return -ENOMEM;
 769                 mutex_lock(&ch->lock);
 770
 771         voltag_retry:
 772                 memset(ch_cmd, 0, sizeof(ch_cmd));
 773                 ch_cmd[0] = READ_ELEMENT_STATUS;
 774                 ch_cmd[1] = ((ch->device->lun & 0x7) << 5) |
 775                         (ch->voltags ? 0x10 : 0) |
 776                         ch_elem_to_typecode(ch,elem);
 777                 ch_cmd[2] = (elem >> 8) & 0xff;
 778                 ch_cmd[3] = elem        & 0xff;
 779                 ch_cmd[5] = 1;
 780                 ch_cmd[9] = 255;
 781
 782                 result = ch_do_scsi(ch, ch_cmd, 12,
 783                                     buffer, 256, DMA_FROM_DEVICE);
 784                 if (!result) {
 785                         cge.cge_status = buffer[18];
 786                         cge.cge_flags = 0;
 787                         if (buffer[18] & CESTATUS_EXCEPT) {
 788                                 cge.cge_errno = EIO;
 789                         }
 790                         if (buffer[25] & 0x80) {
 791                                 cge.cge_flags |= CGE_SRC;
 792                                 if (buffer[25] & 0x40)
 793                                         cge.cge_flags |= CGE_INVERT;
 794                                 elem = (buffer[26]<<8) | buffer[27];
 795                                 for (i = 0; i < 4; i++) {
 796                                         if (elem >= ch->firsts[i] &&
 797                                             elem <  ch->firsts[i] + ch->counts[i]) {
 798                                                 cge.cge_srctype = i;
 799                                                 cge.cge_srcunit = elem-ch->firsts[i];
 800                                         }
 801                                 }
 802                         }
 803                         if ((buffer[22] & 0x30) == 0x30) {
 804                                 cge.cge_flags |= CGE_IDLUN;
 805                                 cge.cge_id  = buffer[23];
 806                                 cge.cge_lun = buffer[22] & 7;
 807                         }
 808                         if (buffer[9] & 0x80) {
 809                                 cge.cge_flags |= CGE_PVOLTAG;
 810                                 memcpy(cge.cge_pvoltag,buffer+28,36);
 811                         }
 812                         if (buffer[9] & 0x40) {
 813                                 cge.cge_flags |= CGE_AVOLTAG;
 814                                 memcpy(cge.cge_avoltag,buffer+64,36);
 815                         }
 816                 } else if (ch->voltags) {
 817                         ch->voltags = 0;
 818                         VPRINTK(KERN_INFO, "device has no volume tag support\n");
 819                         goto voltag_retry;
 820                 }
 821                 kfree(buffer);
 822                 mutex_unlock(&ch->lock);
 823
 824                 if (copy_to_user(argp, &cge, sizeof (cge)))
 825                         return -EFAULT;
 826                 return result;
 827         }
 828
 829         case CHIOINITELEM:
 830         {
 831                 mutex_lock(&ch->lock);
 832                 retval = ch_init_elem(ch);
 833                 mutex_unlock(&ch->lock);
 834                 return retval;
 835         }
 836
 837         case CHIOSVOLTAG:
 838         {
 839                 struct changer_set_voltag csv;
 840                 int elem;
 841
 842                 if (copy_from_user(&csv, argp, sizeof(csv)))
 843                         return -EFAULT;
 844
 845                 if (0 != ch_checkrange(ch, csv.csv_type, csv.csv_unit)) {
 846                         DPRINTK("CHIOSVOLTAG: invalid parameter\n");
 847                         return -EBADSLT;
 848                 }
 849                 elem = ch->firsts[csv.csv_type] + csv.csv_unit;
 850                 mutex_lock(&ch->lock);
 851                 retval = ch_set_voltag(ch, elem,
 852                                        csv.csv_flags & CSV_AVOLTAG,
 853                                        csv.csv_flags & CSV_CLEARTAG,
 854                                        csv.csv_voltag);
 855                 mutex_unlock(&ch->lock);
 856                 return retval;
 857         }
 858
 859         default:
 860                 return scsi_ioctl(ch->device, cmd, argp);
 861
 862         }
 863 }
 864
 865 #ifdef CONFIG_COMPAT
 866
 867 struct changer_element_status32 {
 868         int             ces_type;
 869         compat_uptr_t   ces_data;
 870 };
 871 #define CHIOGSTATUS32  _IOW('c', 8,struct changer_element_status32)
 872
 873 static long ch_ioctl_compat(struct file * file,
 874                             unsigned int cmd, unsigned long arg)
 875 {
 876         scsi_changer *ch = file->private_data;
 877         int retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
 878                                                         file->f_flags & O_NDELAY);
 879         if (retval)
 880                 return retval;
 881
 882         switch (cmd) {
 883         case CHIOGPARAMS:
 884         case CHIOGVPARAMS:
 885         case CHIOPOSITION:
 886         case CHIOMOVE:
 887         case CHIOEXCHANGE:
 888         case CHIOGELEM:
 889         case CHIOINITELEM:
 890         case CHIOSVOLTAG:
 891                 /* compatible */
 892                 return ch_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 893         case CHIOGSTATUS32:
 894         {
 895                 struct changer_element_status32 ces32;
 896                 unsigned char __user *data;
 897
 898                 if (copy_from_user(&ces32, (void __user *)arg, sizeof (ces32)))
 899                         return -EFAULT;
 900                 if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
 901                         return -EINVAL;
 902
 903                 data = compat_ptr(ces32.ces_data);
 904                 return ch_gstatus(ch, ces32.ces_type, data);
 905         }
 906         default:
 907                 return scsi_compat_ioctl(ch->device, cmd, compat_ptr(arg));
 908
 909         }
 910 }
 911 #endif
 912
 913 /* ------------------------------------------------------------------------ */
 914
 915 static int ch_probe(struct device *dev)
 916 {
 917         struct scsi_device *sd = to_scsi_device(dev);
 918         struct device *class_dev;
 919         int ret;
 920         scsi_changer *ch;
 921
 922         if (sd->type != TYPE_MEDIUM_CHANGER)
 923                 return -ENODEV;
 924
 925         ch = kzalloc(sizeof(*ch), GFP_KERNEL);
 926         if (NULL == ch)
 927                 return -ENOMEM;
 928
 929         idr_preload(GFP_KERNEL);
 930         spin_lock(&ch_index_lock);
 931         ret = idr_alloc(&ch_index_idr, ch, 0, CH_MAX_DEVS + 1, GFP_NOWAIT);
 932         spin_unlock(&ch_index_lock);
 933         idr_preload_end();
 934
 935         if (ret < 0) {
 936                 if (ret == -ENOSPC)
 937                         ret = -ENODEV;
 938                 goto free_ch;
 939         }
 940
 941         ch->minor = ret;
 942         sprintf(ch->name,"ch%d",ch->minor);
 943         ret = scsi_device_get(sd);
 944         if (ret) {
 945                 sdev_printk(KERN_WARNING, sd, "ch%d: failed to get device\n",
 946                             ch->minor);
 947                 goto remove_idr;
 948         }
 949
 950         mutex_init(&ch->lock);
 951         kref_init(&ch->ref);
 952         ch->device = sd;
 953         class_dev = device_create(ch_sysfs_class, dev,
 954                                   MKDEV(SCSI_CHANGER_MAJOR, ch->minor), ch,
 955                                   "s%s", ch->name);
 956         if (IS_ERR(class_dev)) {
 957                 sdev_printk(KERN_WARNING, sd, "ch%d: device_create failed\n",
 958                             ch->minor);
 959                 ret = PTR_ERR(class_dev);
 960                 goto put_device;
 961         }
 962
 963         mutex_lock(&ch->lock);
 964         ret = ch_readconfig(ch);
 965         if (ret) {
 966                 mutex_unlock(&ch->lock);
 967                 goto destroy_dev;
 968         }
 969         if (init)
 970                 ch_init_elem(ch);
 971
 972         mutex_unlock(&ch->lock);
 973         dev_set_drvdata(dev, ch);
 974         sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
 975
 976         return 0;
 977 destroy_dev:
 978         device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
 979 put_device:
 980         scsi_device_put(sd);
 981 remove_idr:
 982         idr_remove(&ch_index_idr, ch->minor);
 983 free_ch:
 984         kfree(ch);
 985         return ret;
 986 }
 987
 988 static int ch_remove(struct device *dev)
 989 {
 990         scsi_changer *ch = dev_get_drvdata(dev);
 991
 992         spin_lock(&ch_index_lock);
 993         idr_remove(&ch_index_idr, ch->minor);
 994         dev_set_drvdata(dev, NULL);
 995         spin_unlock(&ch_index_lock);
 996
 997         device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR,ch->minor));
 998         scsi_device_put(ch->device);
 999         kref_put(&ch->ref, ch_destroy);
1000         return 0;
1001 }
1002
1003 static struct scsi_driver ch_template = {
1004         .gendrv         = {
1005                 .name   = "ch",
1006                 .owner  = THIS_MODULE,
1007                 .probe  = ch_probe,
1008                 .remove = ch_remove,
1009         },
1010 };
1011
1012 static const struct file_operations changer_fops = {
1013         .owner          = THIS_MODULE,
1014         .open           = ch_open,
1015         .release        = ch_release,
1016         .unlocked_ioctl = ch_ioctl,
1017 #ifdef CONFIG_COMPAT
1018         .compat_ioctl   = ch_ioctl_compat,
1019 #endif
1020         .llseek         = noop_llseek,
1021 };
1022
1023 static int __init init_ch_module(void)
1024 {
1025         int rc;
1026
1027         printk(KERN_INFO "SCSI Media Changer driver v" VERSION " \n");
1028         ch_sysfs_class = class_create(THIS_MODULE, "scsi_changer");
1029         if (IS_ERR(ch_sysfs_class)) {
1030                 rc = PTR_ERR(ch_sysfs_class);
1031                 return rc;
1032         }
1033         rc = register_chrdev(SCSI_CHANGER_MAJOR,"ch",&changer_fops);
1034         if (rc < 0) {
1035                 printk("Unable to get major %d for SCSI-Changer\n",
1036                        SCSI_CHANGER_MAJOR);
1037                 goto fail1;
1038         }
1039         rc = scsi_register_driver(&ch_template.gendrv);
1040         if (rc < 0)
1041                 goto fail2;
1042         return 0;
1043
1044  fail2:
1045         unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1046  fail1:
1047         class_destroy(ch_sysfs_class);
1048         return rc;
1049 }
1050
1051 static void __exit exit_ch_module(void)
1052 {
1053         scsi_unregister_driver(&ch_template.gendrv);
1054         unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1055         class_destroy(ch_sysfs_class);
1056         idr_destroy(&ch_index_idr);
1057 }
1058
1059 module_init(init_ch_module);
1060 module_exit(exit_ch_module);