hw/scsi-generic.c

   1 /*
   2  * Generic SCSI Device support
   3  *
   4  * Copyright (c) 2007 Bull S.A.S.
   5  * Based on code by Paul Brook
   6  * Based on code by Fabrice Bellard
   7  *
   8  * Written by Laurent Vivier <Laurent.Vivier@bull.net>
   9  *
  10  * This code is licenced under the LGPL.
  11  *
  12  */
  13
  14 #include "qemu-common.h"
  15 #include "block.h"
  16 #include "scsi-disk.h"
  17
  18 #ifndef __linux__
  19
  20 SCSIDevice *scsi_generic_init(BlockDriverState *bdrv, int tcq,
  21                               scsi_completionfn completion, void *opaque)
  22 {
  23     return NULL;
  24 }
  25
  26 #else /* __linux__ */
  27
  28 //#define DEBUG_SCSI
  29
  30 #ifdef DEBUG_SCSI
  31 #define DPRINTF(fmt, args...) \
  32 do { printf("scsi-generic: " fmt , ##args); } while (0)
  33 #else
  34 #define DPRINTF(fmt, args...) do {} while(0)
  35 #endif
  36
  37 #define BADF(fmt, args...) \
  38 do { fprintf(stderr, "scsi-generic: " fmt , ##args); } while (0)
  39
  40 #include <stdio.h>
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <unistd.h>
  44 #include <scsi/sg.h>
  45 #include <scsi/scsi.h>
  46
  47 #define REWIND 0x01
  48 #define REPORT_DENSITY_SUPPORT 0x44
  49 #define LOAD_UNLOAD 0xa6
  50 #define SET_CD_SPEED 0xbb
  51 #define BLANK 0xa1
  52
  53 #define SCSI_CMD_BUF_SIZE     16
  54 #define SCSI_SENSE_BUF_SIZE 96
  55
  56 #define SG_ERR_DRIVER_TIMEOUT 0x06
  57 #define SG_ERR_DRIVER_SENSE 0x08
  58
  59 #ifndef MAX_UINT
  60 #define MAX_UINT ((unsigned int)-1)
  61 #endif
  62
  63 typedef struct SCSIRequest {
  64     BlockDriverAIOCB *aiocb;
  65     struct SCSIRequest *next;
  66     SCSIDeviceState *dev;
  67     uint32_t tag;
  68     uint8_t cmd[SCSI_CMD_BUF_SIZE];
  69     int cmdlen;
  70     uint8_t *buf;
  71     int buflen;
  72     int len;
  73     sg_io_hdr_t io_header;
  74 } SCSIRequest;
  75
  76 struct SCSIDeviceState
  77 {
  78     SCSIRequest *requests;
  79     BlockDriverState *bdrv;
  80     int type;
  81     int blocksize;
  82     int lun;
  83     scsi_completionfn completion;
  84     void *opaque;
  85     int driver_status;
  86     uint8_t sensebuf[SCSI_SENSE_BUF_SIZE];
  87     uint8_t senselen;
  88 };
  89
  90 /* Global pool of SCSIRequest structures.  */
  91 static SCSIRequest *free_requests = NULL;
  92
  93 static SCSIRequest *scsi_new_request(SCSIDeviceState *s, uint32_t tag)
  94 {
  95     SCSIRequest *r;
  96
  97     if (free_requests) {
  98         r = free_requests;
  99         free_requests = r->next;
 100     } else {
 101         r = qemu_malloc(sizeof(SCSIRequest));
 102         r->buf = NULL;
 103         r->buflen = 0;
 104     }
 105     r->dev = s;
 106     r->tag = tag;
 107     memset(r->cmd, 0, sizeof(r->cmd));
 108     memset(&r->io_header, 0, sizeof(r->io_header));
 109     r->cmdlen = 0;
 110     r->len = 0;
 111     r->aiocb = NULL;
 112
 113     /* link */
 114
 115     r->next = s->requests;
 116     s->requests = r;
 117     return r;
 118 }
 119
 120 static void scsi_remove_request(SCSIRequest *r)
 121 {
 122     SCSIRequest *last;
 123     SCSIDeviceState *s = r->dev;
 124
 125     if (s->requests == r) {
 126         s->requests = r->next;
 127     } else {
 128         last = s->requests;
 129         while (last && last->next != r)
 130             last = last->next;
 131         if (last) {
 132             last->next = r->next;
 133         } else {
 134             BADF("Orphaned request\n");
 135         }
 136     }
 137     r->next = free_requests;
 138     free_requests = r;
 139 }
 140
 141 static SCSIRequest *scsi_find_request(SCSIDeviceState *s, uint32_t tag)
 142 {
 143     SCSIRequest *r;
 144
 145     r = s->requests;
 146     while (r && r->tag != tag)
 147         r = r->next;
 148
 149     return r;
 150 }
 151
 152 /* Helper function for command completion.  */
 153 static void scsi_command_complete(void *opaque, int ret)
 154 {
 155     SCSIRequest *r = (SCSIRequest *)opaque;
 156     SCSIDeviceState *s = r->dev;
 157     uint32_t tag;
 158     int status;
 159
 160     s->driver_status = r->io_header.driver_status;
 161     if (s->driver_status & SG_ERR_DRIVER_SENSE)
 162         s->senselen = r->io_header.sb_len_wr;
 163
 164     if (ret != 0)
 165         status = BUSY << 1;
 166     else {
 167         if (s->driver_status & SG_ERR_DRIVER_TIMEOUT) {
 168             status = BUSY << 1;
 169             BADF("Driver Timeout\n");
 170         } else if (r->io_header.status)
 171             status = r->io_header.status;
 172         else if (s->driver_status & SG_ERR_DRIVER_SENSE)
 173             status = CHECK_CONDITION << 1;
 174         else
 175             status = GOOD << 1;
 176     }
 177     DPRINTF("Command complete 0x%p tag=0x%x status=%d\n",
 178             r, r->tag, status);
 179     tag = r->tag;
 180     scsi_remove_request(r);
 181     s->completion(s->opaque, SCSI_REASON_DONE, tag, status);
 182 }
 183
 184 /* Cancel a pending data transfer.  */
 185 static void scsi_cancel_io(SCSIDevice *d, uint32_t tag)
 186 {
 187     DPRINTF("scsi_cancel_io 0x%x\n", tag);
 188     SCSIDeviceState *s = d->state;
 189     SCSIRequest *r;
 190     DPRINTF("Cancel tag=0x%x\n", tag);
 191     r = scsi_find_request(s, tag);
 192     if (r) {
 193         if (r->aiocb)
 194             bdrv_aio_cancel(r->aiocb);
 195         r->aiocb = NULL;
 196         scsi_remove_request(r);
 197     }
 198 }
 199
 200 static int execute_command(BlockDriverState *bdrv,
 201                            SCSIRequest *r, int direction,
 202                            BlockDriverCompletionFunc *complete)
 203 {
 204
 205     r->io_header.interface_id = 'S';
 206     r->io_header.dxfer_direction = direction;
 207     r->io_header.dxferp = r->buf;
 208     r->io_header.dxfer_len = r->buflen;
 209     r->io_header.cmdp = r->cmd;
 210     r->io_header.cmd_len = r->cmdlen;
 211     r->io_header.mx_sb_len = sizeof(r->dev->sensebuf);
 212     r->io_header.sbp = r->dev->sensebuf;
 213     r->io_header.timeout = MAX_UINT;
 214     r->io_header.usr_ptr = r;
 215     r->io_header.flags |= SG_FLAG_DIRECT_IO;
 216
 217     if (bdrv_pwrite(bdrv, -1, &r->io_header, sizeof(r->io_header)) == -1) {
 218         BADF("execute_command: write failed ! (%d)\n", errno);
 219         return -1;
 220     }
 221     if (complete == NULL) {
 222         int ret;
 223         r->aiocb = NULL;
 224         while ((ret = bdrv_pread(bdrv, -1, &r->io_header,
 225                                            sizeof(r->io_header))) == -1 &&
 226                       errno == EINTR);
 227         if (ret == -1) {
 228             BADF("execute_command: read failed !\n");
 229             return -1;
 230         }
 231         return 0;
 232     }
 233
 234     r->aiocb = bdrv_aio_read(bdrv, 0, (uint8_t*)&r->io_header,
 235                           -(int64_t)sizeof(r->io_header), complete, r);
 236     if (r->aiocb == NULL) {
 237         BADF("execute_command: read failed !\n");
 238         return -1;
 239     }
 240
 241     return 0;
 242 }
 243
 244 static void scsi_read_complete(void * opaque, int ret)
 245 {
 246     SCSIRequest *r = (SCSIRequest *)opaque;
 247     SCSIDeviceState *s = r->dev;
 248     int len;
 249
 250     if (ret) {
 251         DPRINTF("IO error\n");
 252         scsi_command_complete(r, ret);
 253         return;
 254     }
 255     len = r->io_header.dxfer_len - r->io_header.resid;
 256     DPRINTF("Data ready tag=0x%x len=%d\n", r->tag, len);
 257
 258     r->len = -1;
 259     s->completion(s->opaque, SCSI_REASON_DATA, r->tag, len);
 260     if (len == 0)
 261         scsi_command_complete(r, 0);
 262 }
 263
 264 /* Read more data from scsi device into buffer.  */
 265 static void scsi_read_data(SCSIDevice *d, uint32_t tag)
 266 {
 267     SCSIDeviceState *s = d->state;
 268     SCSIRequest *r;
 269     int ret;
 270
 271     DPRINTF("scsi_read_data 0x%x\n", tag);
 272     r = scsi_find_request(s, tag);
 273     if (!r) {
 274         BADF("Bad read tag 0x%x\n", tag);
 275         /* ??? This is the wrong error.  */
 276         scsi_command_complete(r, -EINVAL);
 277         return;
 278     }
 279
 280     if (r->len == -1) {
 281         scsi_command_complete(r, 0);
 282         return;
 283     }
 284
 285     if (r->cmd[0] == REQUEST_SENSE && s->driver_status & SG_ERR_DRIVER_SENSE)
 286     {
 287         s->senselen = MIN(r->len, s->senselen);
 288         memcpy(r->buf, s->sensebuf, s->senselen);
 289         r->io_header.driver_status = 0;
 290         r->io_header.status = 0;
 291         r->io_header.dxfer_len  = s->senselen;
 292         r->len = -1;
 293         DPRINTF("Data ready tag=0x%x len=%d\n", r->tag, s->senselen);
 294         DPRINTF("Sense: %d %d %d %d %d %d %d %d\n",
 295                 r->buf[0], r->buf[1], r->buf[2], r->buf[3],
 296                 r->buf[4], r->buf[5], r->buf[6], r->buf[7]);
 297         s->completion(s->opaque, SCSI_REASON_DATA, r->tag, s->senselen);
 298         return;
 299     }
 300
 301     ret = execute_command(s->bdrv, r, SG_DXFER_FROM_DEV, scsi_read_complete);
 302     if (ret == -1) {
 303         scsi_command_complete(r, -EINVAL);
 304         return;
 305     }
 306 }
 307
 308 static void scsi_write_complete(void * opaque, int ret)
 309 {
 310     SCSIRequest *r = (SCSIRequest *)opaque;
 311
 312     DPRINTF("scsi_write_complete() ret = %d\n", ret);
 313     if (ret) {
 314         DPRINTF("IO error\n");
 315         scsi_command_complete(r, ret);
 316         return;
 317     }
 318
 319     if (r->cmd[0] == MODE_SELECT && r->cmd[4] == 12 &&
 320         r->dev->type == TYPE_TAPE) {
 321         r->dev->blocksize = (r->buf[9] << 16) | (r->buf[10] << 8) | r->buf[11];
 322         DPRINTF("block size %d\n", r->dev->blocksize);
 323     }
 324
 325     scsi_command_complete(r, ret);
 326 }
 327
 328 /* Write data to a scsi device.  Returns nonzero on failure.
 329    The transfer may complete asynchronously.  */
 330 static int scsi_write_data(SCSIDevice *d, uint32_t tag)
 331 {
 332     SCSIDeviceState *s = d->state;
 333     SCSIRequest *r;
 334     int ret;
 335
 336     DPRINTF("scsi_write_data 0x%x\n", tag);
 337     r = scsi_find_request(s, tag);
 338     if (!r) {
 339         BADF("Bad write tag 0x%x\n", tag);
 340         /* ??? This is the wrong error.  */
 341         scsi_command_complete(r, -EINVAL);
 342         return 0;
 343     }
 344
 345     if (r->len == 0) {
 346         r->len = r->buflen;
 347         s->completion(s->opaque, SCSI_REASON_DATA, r->tag, r->len);
 348         return 0;
 349     }
 350
 351     ret = execute_command(s->bdrv, r, SG_DXFER_TO_DEV, scsi_write_complete);
 352     if (ret == -1) {
 353         scsi_command_complete(r, -EINVAL);
 354         return 1;
 355     }
 356
 357     return 0;
 358 }
 359
 360 /* Return a pointer to the data buffer.  */
 361 static uint8_t *scsi_get_buf(SCSIDevice *d, uint32_t tag)
 362 {
 363     SCSIDeviceState *s = d->state;
 364     SCSIRequest *r;
 365     r = scsi_find_request(s, tag);
 366     if (!r) {
 367         BADF("Bad buffer tag 0x%x\n", tag);
 368         return NULL;
 369     }
 370     return r->buf;
 371 }
 372
 373 static int scsi_length(uint8_t *cmd, int blocksize, int *cmdlen, uint32_t *len)
 374 {
 375     switch (cmd[0] >> 5) {
 376     case 0:
 377         *len = cmd[4];
 378         *cmdlen = 6;
 379         /* length 0 means 256 blocks */
 380         if (*len == 0)
 381             *len = 256;
 382         break;
 383     case 1:
 384     case 2:
 385         *len = cmd[8] | (cmd[7] << 8);
 386         *cmdlen = 10;
 387         break;
 388     case 4:
 389         *len = cmd[13] | (cmd[12] << 8) | (cmd[11] << 16) | (cmd[10] << 24);
 390         *cmdlen = 16;
 391         break;
 392     case 5:
 393         *len = cmd[9] | (cmd[8] << 8) | (cmd[7] << 16) | (cmd[6] << 24);
 394         *cmdlen = 12;
 395         break;
 396     default:
 397         return -1;
 398     }
 399
 400     switch(cmd[0]) {
 401     case TEST_UNIT_READY:
 402     case REZERO_UNIT:
 403     case START_STOP:
 404     case SEEK_6:
 405     case WRITE_FILEMARKS:
 406     case SPACE:
 407     case ERASE:
 408     case ALLOW_MEDIUM_REMOVAL:
 409     case VERIFY:
 410     case SEEK_10:
 411     case SYNCHRONIZE_CACHE:
 412     case LOCK_UNLOCK_CACHE:
 413     case LOAD_UNLOAD:
 414     case SET_CD_SPEED:
 415     case SET_LIMITS:
 416     case WRITE_LONG:
 417     case MOVE_MEDIUM:
 418     case UPDATE_BLOCK:
 419         *len = 0;
 420         break;
 421     case MODE_SENSE:
 422         break;
 423     case WRITE_SAME:
 424         *len = 1;
 425         break;
 426     case READ_CAPACITY:
 427         *len = 8;
 428         break;
 429     case READ_BLOCK_LIMITS:
 430         *len = 6;
 431         break;
 432     case READ_POSITION:
 433         *len = 20;
 434         break;
 435     case SEND_VOLUME_TAG:
 436         *len *= 40;
 437         break;
 438     case MEDIUM_SCAN:
 439         *len *= 8;
 440         break;
 441     case WRITE_10:
 442         cmd[1] &= ~0x08;        /* disable FUA */
 443     case WRITE_VERIFY:
 444     case WRITE_6:
 445     case WRITE_12:
 446     case WRITE_VERIFY_12:
 447         *len *= blocksize;
 448         break;
 449     case READ_10:
 450         cmd[1] &= ~0x08;        /* disable FUA */
 451     case READ_6:
 452     case READ_REVERSE:
 453     case RECOVER_BUFFERED_DATA:
 454     case READ_12:
 455         *len *= blocksize;
 456         break;
 457     case INQUIRY:
 458         *len = cmd[4] | (cmd[3] << 8);
 459         break;
 460     }
 461     return 0;
 462 }
 463
 464 static int scsi_stream_length(uint8_t *cmd, int blocksize, int *cmdlen, uint32_t *len)
 465 {
 466     switch(cmd[0]) {
 467     /* stream commands */
 468     case READ_6:
 469     case READ_REVERSE:
 470     case RECOVER_BUFFERED_DATA:
 471     case WRITE_6:
 472         *cmdlen = 6;
 473         *len = cmd[4] | (cmd[3] << 8) | (cmd[2] << 16);
 474         if (cmd[1] & 0x01) /* fixed */
 475             *len *= blocksize;
 476         break;
 477     case REWIND:
 478     case START_STOP:
 479         *cmdlen = 6;
 480         *len = 0;
 481         cmd[1] = 0x01;  /* force IMMED, otherwise qemu waits end of command */
 482         break;
 483     /* generic commands */
 484     default:
 485         return scsi_length(cmd, blocksize, cmdlen, len);
 486     }
 487     return 0;
 488 }
 489
 490 static int is_write(int command)
 491 {
 492     switch (command) {
 493     case COPY:
 494     case COPY_VERIFY:
 495     case COMPARE:
 496     case CHANGE_DEFINITION:
 497     case LOG_SELECT:
 498     case MODE_SELECT:
 499     case MODE_SELECT_10:
 500     case SEND_DIAGNOSTIC:
 501     case WRITE_BUFFER:
 502     case FORMAT_UNIT:
 503     case REASSIGN_BLOCKS:
 504     case RESERVE:
 505     case SEARCH_EQUAL:
 506     case SEARCH_HIGH:
 507     case SEARCH_LOW:
 508     case WRITE_6:
 509     case WRITE_10:
 510     case WRITE_VERIFY:
 511     case UPDATE_BLOCK:
 512     case WRITE_LONG:
 513     case WRITE_SAME:
 514     case SEARCH_HIGH_12:
 515     case SEARCH_EQUAL_12:
 516     case SEARCH_LOW_12:
 517     case WRITE_12:
 518     case WRITE_VERIFY_12:
 519     case SET_WINDOW:
 520     case MEDIUM_SCAN:
 521     case SEND_VOLUME_TAG:
 522     case WRITE_LONG_2:
 523         return 1;
 524     }
 525     return 0;
 526 }
 527
 528 /* Execute a scsi command.  Returns the length of the data expected by the
 529    command.  This will be Positive for data transfers from the device
 530    (eg. disk reads), negative for transfers to the device (eg. disk writes),
 531    and zero if the command does not transfer any data.  */
 532
 533 static int32_t scsi_send_command(SCSIDevice *d, uint32_t tag,
 534                                  uint8_t *cmd, int lun)
 535 {
 536     SCSIDeviceState *s = d->state;
 537     uint32_t len=0;
 538     int cmdlen=0;
 539     SCSIRequest *r;
 540     int ret;
 541
 542     if (s->type == TYPE_TAPE) {
 543         if (scsi_stream_length(cmd, s->blocksize, &cmdlen, &len) == -1) {
 544             BADF("Unsupported command length, command %x\n", cmd[0]);
 545             return 0;
 546         }
 547      } else {
 548         if (scsi_length(cmd, s->blocksize, &cmdlen, &len) == -1) {
 549             BADF("Unsupported command length, command %x\n", cmd[0]);
 550             return 0;
 551         }
 552     }
 553
 554     DPRINTF("Command: lun=%d tag=0x%x data=0x%02x len %d\n", lun, tag,
 555             cmd[0], len);
 556
 557     if (cmd[0] != REQUEST_SENSE &&
 558         (lun != s->lun || (cmd[1] >> 5) != s->lun)) {
 559         DPRINTF("Unimplemented LUN %d\n", lun ? lun : cmd[1] >> 5);
 560
 561         s->sensebuf[0] = 0x70;
 562         s->sensebuf[1] = 0x00;
 563         s->sensebuf[2] = ILLEGAL_REQUEST;
 564         s->sensebuf[3] = 0x00;
 565         s->sensebuf[4] = 0x00;
 566         s->sensebuf[5] = 0x00;
 567         s->sensebuf[6] = 0x00;
 568         s->senselen = 7;
 569         s->driver_status = SG_ERR_DRIVER_SENSE;
 570         s->completion(s->opaque, SCSI_REASON_DONE, tag, CHECK_CONDITION << 1);
 571         return 0;
 572     }
 573
 574     r = scsi_find_request(s, tag);
 575     if (r) {
 576         BADF("Tag 0x%x already in use %p\n", tag, r);
 577         scsi_cancel_io(d, tag);
 578     }
 579     r = scsi_new_request(s, tag);
 580
 581     memcpy(r->cmd, cmd, cmdlen);
 582     r->cmdlen = cmdlen;
 583
 584     if (len == 0) {
 585         if (r->buf != NULL)
 586             free(r->buf);
 587         r->buflen = 0;
 588         r->buf = NULL;
 589         ret = execute_command(s->bdrv, r, SG_DXFER_NONE, scsi_command_complete);
 590         if (ret == -1) {
 591             scsi_command_complete(r, -EINVAL);
 592             return 0;
 593         }
 594         return 0;
 595     }
 596
 597     if (r->buflen != len) {
 598         if (r->buf != NULL)
 599             free(r->buf);
 600         r->buf = qemu_malloc(len);
 601         r->buflen = len;
 602     }
 603
 604     memset(r->buf, 0, r->buflen);
 605     r->len = len;
 606     if (is_write(cmd[0])) {
 607         r->len = 0;
 608         return -len;
 609     }
 610
 611     return len;
 612 }
 613
 614 static int get_blocksize(BlockDriverState *bdrv)
 615 {
 616     uint8_t cmd[10];
 617     uint8_t buf[8];
 618     uint8_t sensebuf[8];
 619     sg_io_hdr_t io_header;
 620     int ret;
 621
 622     memset(cmd, 0, sizeof(cmd));
 623     memset(buf, 0, sizeof(buf));
 624     cmd[0] = READ_CAPACITY;
 625
 626     memset(&io_header, 0, sizeof(io_header));
 627     io_header.interface_id = 'S';
 628     io_header.dxfer_direction = SG_DXFER_FROM_DEV;
 629     io_header.dxfer_len = sizeof(buf);
 630     io_header.dxferp = buf;
 631     io_header.cmdp = cmd;
 632     io_header.cmd_len = sizeof(cmd);
 633     io_header.mx_sb_len = sizeof(sensebuf);
 634     io_header.sbp = sensebuf;
 635     io_header.timeout = 6000; /* XXX */
 636
 637     ret = bdrv_pwrite(bdrv, -1, &io_header, sizeof(io_header));
 638     if (ret == -1)
 639         return -1;
 640
 641     while ((ret = bdrv_pread(bdrv, -1, &io_header, sizeof(io_header))) == -1 &&
 642            errno == EINTR);
 643
 644     if (ret == -1)
 645         return -1;
 646
 647     return (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7];
 648 }
 649
 650 static int get_stream_blocksize(BlockDriverState *bdrv)
 651 {
 652     uint8_t cmd[6];
 653     uint8_t buf[12];
 654     uint8_t sensebuf[8];
 655     sg_io_hdr_t io_header;
 656     int ret;
 657
 658     memset(cmd, 0, sizeof(cmd));
 659     memset(buf, 0, sizeof(buf));
 660     cmd[0] = MODE_SENSE;
 661     cmd[4] = sizeof(buf);
 662
 663     memset(&io_header, 0, sizeof(io_header));
 664     io_header.interface_id = 'S';
 665     io_header.dxfer_direction = SG_DXFER_FROM_DEV;
 666     io_header.dxfer_len = sizeof(buf);
 667     io_header.dxferp = buf;
 668     io_header.cmdp = cmd;
 669     io_header.cmd_len = sizeof(cmd);
 670     io_header.mx_sb_len = sizeof(sensebuf);
 671     io_header.sbp = sensebuf;
 672     io_header.timeout = 6000; /* XXX */
 673
 674     ret = bdrv_pwrite(bdrv, -1, &io_header, sizeof(io_header));
 675     if (ret == -1)
 676         return -1;
 677
 678     while ((ret = bdrv_pread(bdrv, -1, &io_header, sizeof(io_header))) == -1 &&
 679            errno == EINTR);
 680
 681     if (ret == -1)
 682         return -1;
 683
 684     return (buf[9] << 16) | (buf[10] << 8) | buf[11];
 685 }
 686
 687 static void scsi_destroy(SCSIDevice *d)
 688 {
 689     SCSIRequest *r, *n;
 690
 691     r = d->state->requests;
 692     while (r) {
 693         n = r->next;
 694         qemu_free(r);
 695         r = n;
 696     }
 697
 698     r = free_requests;
 699     while (r) {
 700         n = r->next;
 701         qemu_free(r);
 702         r = n;
 703     }
 704
 705     qemu_free(d->state);
 706     qemu_free(d);
 707 }
 708
 709 SCSIDevice *scsi_generic_init(BlockDriverState *bdrv, int tcq,
 710                               scsi_completionfn completion, void *opaque)
 711 {
 712     int sg_version;
 713     SCSIDevice *d;
 714     SCSIDeviceState *s;
 715     struct sg_scsi_id scsiid;
 716
 717     /* check we are really using a /dev/sg* file */
 718
 719     if (!bdrv_is_sg(bdrv))
 720         return NULL;
 721
 722     /* check we are using a driver managing SG_IO (version 3 and after */
 723
 724     if (bdrv_ioctl(bdrv, SG_GET_VERSION_NUM, &sg_version) < 0 ||
 725         sg_version < 30000)
 726         return NULL;
 727
 728     /* get LUN of the /dev/sg? */
 729
 730     if (bdrv_ioctl(bdrv, SG_GET_SCSI_ID, &scsiid))
 731         return NULL;
 732
 733     /* define device state */
 734
 735     s = (SCSIDeviceState *)qemu_mallocz(sizeof(SCSIDeviceState));
 736     s->bdrv = bdrv;
 737     s->requests = NULL;
 738     s->completion = completion;
 739     s->opaque = opaque;
 740     s->lun = scsiid.lun;
 741     DPRINTF("LUN %d\n", s->lun);
 742     s->type = scsiid.scsi_type;
 743     DPRINTF("device type %d\n", s->type);
 744     if (s->type == TYPE_TAPE) {
 745         s->blocksize = get_stream_blocksize(s->bdrv);
 746         if (s->blocksize == -1)
 747             s->blocksize = 0;
 748     } else {
 749         s->blocksize = get_blocksize(s->bdrv);
 750         /* removable media returns 0 if not present */
 751         if (s->blocksize <= 0) {
 752             if (s->type == TYPE_ROM || s->type  == TYPE_WORM)
 753                 s->blocksize = 2048;
 754             else
 755                 s->blocksize = 512;
 756         }
 757     }
 758     DPRINTF("block size %d\n", s->blocksize);
 759     s->driver_status = 0;
 760     memset(s->sensebuf, 0, sizeof(s->sensebuf));
 761
 762     /* define function to manage device */
 763
 764     d = (SCSIDevice *)qemu_mallocz(sizeof(SCSIDevice));
 765     d->state = s;
 766     d->destroy = scsi_destroy;
 767     d->send_command = scsi_send_command;
 768     d->read_data = scsi_read_data;
 769     d->write_data = scsi_write_data;
 770     d->cancel_io = scsi_cancel_io;
 771     d->get_buf = scsi_get_buf;
 772
 773     return d;
 774 }
 775 #endif /* __linux__ */