1/* 2 * ATAPI support. 3 */ 4 5#include <linux/kernel.h> 6#include <linux/cdrom.h> 7#include <linux/delay.h> 8#include <linux/export.h> 9#include <linux/ide.h> 10#include <linux/scatterlist.h> 11#include <linux/gfp.h> 12 13#include <scsi/scsi.h> 14 15#define DRV_NAME "ide-atapi" 16#define PFX DRV_NAME ": " 17 18#ifdef DEBUG 19#define debug_log(fmt, args...) \ 20 printk(KERN_INFO "ide: " fmt, ## args) 21#else 22#define debug_log(fmt, args...) do {} while (0) 23#endif 24 25#define ATAPI_MIN_CDB_BYTES 12 26 27static inline int dev_is_idecd(ide_drive_t *drive) 28{ 29 return drive->media == ide_cdrom || drive->media == ide_optical; 30} 31 32/* 33 * Check whether we can support a device, 34 * based on the ATAPI IDENTIFY command results. 35 */ 36int ide_check_atapi_device(ide_drive_t *drive, const char *s) 37{ 38 u16 *id = drive->id; 39 u8 gcw[2], protocol, device_type, removable, drq_type, packet_size; 40 41 *((u16 *)&gcw) = id[ATA_ID_CONFIG]; 42 43 protocol = (gcw[1] & 0xC0) >> 6; 44 device_type = gcw[1] & 0x1F; 45 removable = (gcw[0] & 0x80) >> 7; 46 drq_type = (gcw[0] & 0x60) >> 5; 47 packet_size = gcw[0] & 0x03; 48 49#ifdef CONFIG_PPC 50 /* kludge for Apple PowerBook internal zip */ 51 if (drive->media == ide_floppy && device_type == 5 && 52 !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") && 53 strstr((char *)&id[ATA_ID_PROD], "ZIP")) 54 device_type = 0; 55#endif 56 57 if (protocol != 2) 58 printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n", 59 s, drive->name, protocol); 60 else if ((drive->media == ide_floppy && device_type != 0) || 61 (drive->media == ide_tape && device_type != 1)) 62 printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n", 63 s, drive->name, device_type); 64 else if (removable == 0) 65 printk(KERN_ERR "%s: %s: the removable flag is not set\n", 66 s, drive->name); 67 else if (drive->media == ide_floppy && drq_type == 3) 68 printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not " 69 "supported\n", s, drive->name, drq_type); 70 else if (packet_size != 0) 71 printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 " 72 "bytes\n", s, drive->name, packet_size); 73 else 74 return 1; 75 return 0; 76} 77EXPORT_SYMBOL_GPL(ide_check_atapi_device); 78 79void ide_init_pc(struct ide_atapi_pc *pc) 80{ 81 memset(pc, 0, sizeof(*pc)); 82} 83EXPORT_SYMBOL_GPL(ide_init_pc); 84 85/* 86 * Add a special packet command request to the tail of the request queue, 87 * and wait for it to be serviced. 88 */ 89int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk, 90 struct ide_atapi_pc *pc, void *buf, unsigned int bufflen) 91{ 92 struct request *rq; 93 int error; 94 95 rq = blk_get_request(drive->queue, READ, __GFP_WAIT); 96 rq->cmd_type = REQ_TYPE_SPECIAL; 97 rq->special = (char *)pc; 98 99 if (buf && bufflen) { 100 error = blk_rq_map_kern(drive->queue, rq, buf, bufflen, 101 GFP_NOIO); 102 if (error) 103 goto put_req; 104 } 105 106 memcpy(rq->cmd, pc->c, 12); 107 if (drive->media == ide_tape) 108 rq->cmd[13] = REQ_IDETAPE_PC1; 109 error = blk_execute_rq(drive->queue, disk, rq, 0); 110put_req: 111 blk_put_request(rq); 112 return error; 113} 114EXPORT_SYMBOL_GPL(ide_queue_pc_tail); 115 116int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk) 117{ 118 struct ide_atapi_pc pc; 119 120 ide_init_pc(&pc); 121 pc.c[0] = TEST_UNIT_READY; 122 123 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0); 124} 125EXPORT_SYMBOL_GPL(ide_do_test_unit_ready); 126 127int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start) 128{ 129 struct ide_atapi_pc pc; 130 131 ide_init_pc(&pc); 132 pc.c[0] = START_STOP; 133 pc.c[4] = start; 134 135 if (drive->media == ide_tape) 136 pc.flags |= PC_FLAG_WAIT_FOR_DSC; 137 138 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0); 139} 140EXPORT_SYMBOL_GPL(ide_do_start_stop); 141 142int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on) 143{ 144 struct ide_atapi_pc pc; 145 146 if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0) 147 return 0; 148 149 ide_init_pc(&pc); 150 pc.c[0] = ALLOW_MEDIUM_REMOVAL; 151 pc.c[4] = on; 152 153 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0); 154} 155EXPORT_SYMBOL_GPL(ide_set_media_lock); 156 157void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc) 158{ 159 ide_init_pc(pc); 160 pc->c[0] = REQUEST_SENSE; 161 if (drive->media == ide_floppy) { 162 pc->c[4] = 255; 163 pc->req_xfer = 18; 164 } else { 165 pc->c[4] = 20; 166 pc->req_xfer = 20; 167 } 168} 169EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd); 170 171void ide_prep_sense(ide_drive_t *drive, struct request *rq) 172{ 173 struct request_sense *sense = &drive->sense_data; 174 struct request *sense_rq = &drive->sense_rq; 175 unsigned int cmd_len, sense_len; 176 int err; 177 178 switch (drive->media) { 179 case ide_floppy: 180 cmd_len = 255; 181 sense_len = 18; 182 break; 183 case ide_tape: 184 cmd_len = 20; 185 sense_len = 20; 186 break; 187 default: 188 cmd_len = 18; 189 sense_len = 18; 190 } 191 192 BUG_ON(sense_len > sizeof(*sense)); 193 194 if (rq->cmd_type == REQ_TYPE_SENSE || drive->sense_rq_armed) 195 return; 196 197 memset(sense, 0, sizeof(*sense)); 198 199 blk_rq_init(rq->q, sense_rq); 200 201 err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len, 202 GFP_NOIO); 203 if (unlikely(err)) { 204 if (printk_ratelimit()) 205 printk(KERN_WARNING PFX "%s: failed to map sense " 206 "buffer\n", drive->name); 207 return; 208 } 209 210 sense_rq->rq_disk = rq->rq_disk; 211 sense_rq->cmd[0] = GPCMD_REQUEST_SENSE; 212 sense_rq->cmd[4] = cmd_len; 213 sense_rq->cmd_type = REQ_TYPE_SENSE; 214 sense_rq->cmd_flags |= REQ_PREEMPT; 215 216 if (drive->media == ide_tape) 217 sense_rq->cmd[13] = REQ_IDETAPE_PC1; 218 219 drive->sense_rq_armed = true; 220} 221EXPORT_SYMBOL_GPL(ide_prep_sense); 222 223int ide_queue_sense_rq(ide_drive_t *drive, void *special) 224{ 225 /* deferred failure from ide_prep_sense() */ 226 if (!drive->sense_rq_armed) { 227 printk(KERN_WARNING PFX "%s: error queuing a sense request\n", 228 drive->name); 229 return -ENOMEM; 230 } 231 232 drive->sense_rq.special = special; 233 drive->sense_rq_armed = false; 234 235 drive->hwif->rq = NULL; 236 237 elv_add_request(drive->queue, &drive->sense_rq, ELEVATOR_INSERT_FRONT); 238 return 0; 239} 240EXPORT_SYMBOL_GPL(ide_queue_sense_rq); 241 242/* 243 * Called when an error was detected during the last packet command. 244 * We queue a request sense packet command at the head of the request 245 * queue. 246 */ 247void ide_retry_pc(ide_drive_t *drive) 248{ 249 struct request *failed_rq = drive->hwif->rq; 250 struct request *sense_rq = &drive->sense_rq; 251 struct ide_atapi_pc *pc = &drive->request_sense_pc; 252 253 (void)ide_read_error(drive); 254 255 /* init pc from sense_rq */ 256 ide_init_pc(pc); 257 memcpy(pc->c, sense_rq->cmd, 12); 258 259 if (drive->media == ide_tape) 260 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC; 261 262 /* 263 * Push back the failed request and put request sense on top 264 * of it. The failed command will be retried after sense data 265 * is acquired. 266 */ 267 drive->hwif->rq = NULL; 268 ide_requeue_and_plug(drive, failed_rq); 269 if (ide_queue_sense_rq(drive, pc)) { 270 blk_start_request(failed_rq); 271 ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq)); 272 } 273} 274EXPORT_SYMBOL_GPL(ide_retry_pc); 275 276int ide_cd_expiry(ide_drive_t *drive) 277{ 278 struct request *rq = drive->hwif->rq; 279 unsigned long wait = 0; 280 281 debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]); 282 283 /* 284 * Some commands are *slow* and normally take a long time to complete. 285 * Usually we can use the ATAPI "disconnect" to bypass this, but not all 286 * commands/drives support that. Let ide_timer_expiry keep polling us 287 * for these. 288 */ 289 switch (rq->cmd[0]) { 290 case GPCMD_BLANK: 291 case GPCMD_FORMAT_UNIT: 292 case GPCMD_RESERVE_RZONE_TRACK: 293 case GPCMD_CLOSE_TRACK: 294 case GPCMD_FLUSH_CACHE: 295 wait = ATAPI_WAIT_PC; 296 break; 297 default: 298 if (!(rq->cmd_flags & REQ_QUIET)) 299 printk(KERN_INFO PFX "cmd 0x%x timed out\n", 300 rq->cmd[0]); 301 wait = 0; 302 break; 303 } 304 return wait; 305} 306EXPORT_SYMBOL_GPL(ide_cd_expiry); 307 308int ide_cd_get_xferlen(struct request *rq) 309{ 310 switch (rq->cmd_type) { 311 case REQ_TYPE_FS: 312 return 32768; 313 case REQ_TYPE_SENSE: 314 case REQ_TYPE_BLOCK_PC: 315 case REQ_TYPE_ATA_PC: 316 return blk_rq_bytes(rq); 317 default: 318 return 0; 319 } 320} 321EXPORT_SYMBOL_GPL(ide_cd_get_xferlen); 322 323void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason) 324{ 325 struct ide_taskfile tf; 326 327 drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT | 328 IDE_VALID_LBAM | IDE_VALID_LBAH); 329 330 *bcount = (tf.lbah << 8) | tf.lbam; 331 *ireason = tf.nsect & 3; 332} 333EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason); 334 335/* 336 * Check the contents of the interrupt reason register and attempt to recover if 337 * there are problems. 338 * 339 * Returns: 340 * - 0 if everything's ok 341 * - 1 if the request has to be terminated. 342 */ 343int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len, 344 int ireason, int rw) 345{ 346 ide_hwif_t *hwif = drive->hwif; 347 348 debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw); 349 350 if (ireason == (!rw << 1)) 351 return 0; 352 else if (ireason == (rw << 1)) { 353 printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n", 354 drive->name, __func__); 355 356 if (dev_is_idecd(drive)) 357 ide_pad_transfer(drive, rw, len); 358 } else if (!rw && ireason == ATAPI_COD) { 359 if (dev_is_idecd(drive)) { 360 /* 361 * Some drives (ASUS) seem to tell us that status info 362 * is available. Just get it and ignore. 363 */ 364 (void)hwif->tp_ops->read_status(hwif); 365 return 0; 366 } 367 } else { 368 if (ireason & ATAPI_COD) 369 printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name, 370 __func__); 371 372 /* drive wants a command packet, or invalid ireason... */ 373 printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n", 374 drive->name, __func__, ireason); 375 } 376 377 if (dev_is_idecd(drive) && rq->cmd_type == REQ_TYPE_ATA_PC) 378 rq->cmd_flags |= REQ_FAILED; 379 380 return 1; 381} 382EXPORT_SYMBOL_GPL(ide_check_ireason); 383 384/* 385 * This is the usual interrupt handler which will be called during a packet 386 * command. We will transfer some of the data (as requested by the drive) 387 * and will re-point interrupt handler to us. 388 */ 389static ide_startstop_t ide_pc_intr(ide_drive_t *drive) 390{ 391 struct ide_atapi_pc *pc = drive->pc; 392 ide_hwif_t *hwif = drive->hwif; 393 struct ide_cmd *cmd = &hwif->cmd; 394 struct request *rq = hwif->rq; 395 const struct ide_tp_ops *tp_ops = hwif->tp_ops; 396 unsigned int timeout, done; 397 u16 bcount; 398 u8 stat, ireason, dsc = 0; 399 u8 write = !!(pc->flags & PC_FLAG_WRITING); 400 401 debug_log("Enter %s - interrupt handler\n", __func__); 402 403 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD 404 : WAIT_TAPE_CMD; 405 406 /* Clear the interrupt */ 407 stat = tp_ops->read_status(hwif); 408 409 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 410 int rc; 411 412 drive->waiting_for_dma = 0; 413 rc = hwif->dma_ops->dma_end(drive); 414 ide_dma_unmap_sg(drive, cmd); 415 416 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) { 417 if (drive->media == ide_floppy) 418 printk(KERN_ERR PFX "%s: DMA %s error\n", 419 drive->name, rq_data_dir(pc->rq) 420 ? "write" : "read"); 421 pc->flags |= PC_FLAG_DMA_ERROR; 422 } else 423 rq->resid_len = 0; 424 debug_log("%s: DMA finished\n", drive->name); 425 } 426 427 /* No more interrupts */ 428 if ((stat & ATA_DRQ) == 0) { 429 int uptodate, error; 430 431 debug_log("Packet command completed, %d bytes transferred\n", 432 blk_rq_bytes(rq)); 433 434 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 435 436 local_irq_enable_in_hardirq(); 437 438 if (drive->media == ide_tape && 439 (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE) 440 stat &= ~ATA_ERR; 441 442 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) { 443 /* Error detected */ 444 debug_log("%s: I/O error\n", drive->name); 445 446 if (drive->media != ide_tape) 447 pc->rq->errors++; 448 449 if (rq->cmd[0] == REQUEST_SENSE) { 450 printk(KERN_ERR PFX "%s: I/O error in request " 451 "sense command\n", drive->name); 452 return ide_do_reset(drive); 453 } 454 455 debug_log("[cmd %x]: check condition\n", rq->cmd[0]); 456 457 /* Retry operation */ 458 ide_retry_pc(drive); 459 460 /* queued, but not started */ 461 return ide_stopped; 462 } 463 pc->error = 0; 464 465 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0) 466 dsc = 1; 467 468 /* 469 * ->pc_callback() might change rq->data_len for 470 * residual count, cache total length. 471 */ 472 done = blk_rq_bytes(rq); 473 474 /* Command finished - Call the callback function */ 475 uptodate = drive->pc_callback(drive, dsc); 476 477 if (uptodate == 0) 478 drive->failed_pc = NULL; 479 480 if (rq->cmd_type == REQ_TYPE_SPECIAL) { 481 rq->errors = 0; 482 error = 0; 483 } else { 484 485 if (rq->cmd_type != REQ_TYPE_FS && uptodate <= 0) { 486 if (rq->errors == 0) 487 rq->errors = -EIO; 488 } 489 490 error = uptodate ? 0 : -EIO; 491 } 492 493 ide_complete_rq(drive, error, blk_rq_bytes(rq)); 494 return ide_stopped; 495 } 496 497 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 498 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 499 printk(KERN_ERR PFX "%s: The device wants to issue more " 500 "interrupts in DMA mode\n", drive->name); 501 ide_dma_off(drive); 502 return ide_do_reset(drive); 503 } 504 505 /* Get the number of bytes to transfer on this interrupt. */ 506 ide_read_bcount_and_ireason(drive, &bcount, &ireason); 507 508 if (ide_check_ireason(drive, rq, bcount, ireason, write)) 509 return ide_do_reset(drive); 510 511 done = min_t(unsigned int, bcount, cmd->nleft); 512 ide_pio_bytes(drive, cmd, write, done); 513 514 /* Update transferred byte count */ 515 rq->resid_len -= done; 516 517 bcount -= done; 518 519 if (bcount) 520 ide_pad_transfer(drive, write, bcount); 521 522 debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n", 523 rq->cmd[0], done, bcount, rq->resid_len); 524 525 /* And set the interrupt handler again */ 526 ide_set_handler(drive, ide_pc_intr, timeout); 527 return ide_started; 528} 529 530static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf, 531 u16 bcount, u8 dma) 532{ 533 cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO; 534 cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM | 535 IDE_VALID_FEATURE | valid_tf; 536 cmd->tf.command = ATA_CMD_PACKET; 537 cmd->tf.feature = dma; /* Use PIO/DMA */ 538 cmd->tf.lbam = bcount & 0xff; 539 cmd->tf.lbah = (bcount >> 8) & 0xff; 540} 541 542static u8 ide_read_ireason(ide_drive_t *drive) 543{ 544 struct ide_taskfile tf; 545 546 drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT); 547 548 return tf.nsect & 3; 549} 550 551static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason) 552{ 553 int retries = 100; 554 555 while (retries-- && ((ireason & ATAPI_COD) == 0 || 556 (ireason & ATAPI_IO))) { 557 printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing " 558 "a packet command, retrying\n", drive->name); 559 udelay(100); 560 ireason = ide_read_ireason(drive); 561 if (retries == 0) { 562 printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing" 563 " a packet command, ignoring\n", 564 drive->name); 565 ireason |= ATAPI_COD; 566 ireason &= ~ATAPI_IO; 567 } 568 } 569 570 return ireason; 571} 572 573static int ide_delayed_transfer_pc(ide_drive_t *drive) 574{ 575 /* Send the actual packet */ 576 drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12); 577 578 /* Timeout for the packet command */ 579 return WAIT_FLOPPY_CMD; 580} 581 582static ide_startstop_t ide_transfer_pc(ide_drive_t *drive) 583{ 584 struct ide_atapi_pc *uninitialized_var(pc); 585 ide_hwif_t *hwif = drive->hwif; 586 struct request *rq = hwif->rq; 587 ide_expiry_t *expiry; 588 unsigned int timeout; 589 int cmd_len; 590 ide_startstop_t startstop; 591 u8 ireason; 592 593 if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) { 594 printk(KERN_ERR PFX "%s: Strange, packet command initiated yet " 595 "DRQ isn't asserted\n", drive->name); 596 return startstop; 597 } 598 599 if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) { 600 if (drive->dma) 601 drive->waiting_for_dma = 1; 602 } 603 604 if (dev_is_idecd(drive)) { 605 /* ATAPI commands get padded out to 12 bytes minimum */ 606 cmd_len = COMMAND_SIZE(rq->cmd[0]); 607 if (cmd_len < ATAPI_MIN_CDB_BYTES) 608 cmd_len = ATAPI_MIN_CDB_BYTES; 609 610 timeout = rq->timeout; 611 expiry = ide_cd_expiry; 612 } else { 613 pc = drive->pc; 614 615 cmd_len = ATAPI_MIN_CDB_BYTES; 616 617 /* 618 * If necessary schedule the packet transfer to occur 'timeout' 619 * milliseconds later in ide_delayed_transfer_pc() after the 620 * device says it's ready for a packet. 621 */ 622 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) { 623 timeout = drive->pc_delay; 624 expiry = &ide_delayed_transfer_pc; 625 } else { 626 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD 627 : WAIT_TAPE_CMD; 628 expiry = NULL; 629 } 630 631 ireason = ide_read_ireason(drive); 632 if (drive->media == ide_tape) 633 ireason = ide_wait_ireason(drive, ireason); 634 635 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) { 636 printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while " 637 "issuing a packet command\n", drive->name); 638 639 return ide_do_reset(drive); 640 } 641 } 642 643 hwif->expiry = expiry; 644 645 /* Set the interrupt routine */ 646 ide_set_handler(drive, 647 (dev_is_idecd(drive) ? drive->irq_handler 648 : ide_pc_intr), 649 timeout); 650 651 /* Send the actual packet */ 652 if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0) 653 hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len); 654 655 /* Begin DMA, if necessary */ 656 if (dev_is_idecd(drive)) { 657 if (drive->dma) 658 hwif->dma_ops->dma_start(drive); 659 } else { 660 if (pc->flags & PC_FLAG_DMA_OK) { 661 pc->flags |= PC_FLAG_DMA_IN_PROGRESS; 662 hwif->dma_ops->dma_start(drive); 663 } 664 } 665 666 return ide_started; 667} 668 669ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd) 670{ 671 struct ide_atapi_pc *pc; 672 ide_hwif_t *hwif = drive->hwif; 673 ide_expiry_t *expiry = NULL; 674 struct request *rq = hwif->rq; 675 unsigned int timeout, bytes; 676 u16 bcount; 677 u8 valid_tf; 678 u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT); 679 680 if (dev_is_idecd(drive)) { 681 valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL; 682 bcount = ide_cd_get_xferlen(rq); 683 expiry = ide_cd_expiry; 684 timeout = ATAPI_WAIT_PC; 685 686 if (drive->dma) 687 drive->dma = !ide_dma_prepare(drive, cmd); 688 } else { 689 pc = drive->pc; 690 691 valid_tf = IDE_VALID_DEVICE; 692 bytes = blk_rq_bytes(rq); 693 bcount = ((drive->media == ide_tape) ? bytes 694 : min_t(unsigned int, 695 bytes, 63 * 1024)); 696 697 /* We haven't transferred any data yet */ 698 rq->resid_len = bcount; 699 700 if (pc->flags & PC_FLAG_DMA_ERROR) { 701 pc->flags &= ~PC_FLAG_DMA_ERROR; 702 ide_dma_off(drive); 703 } 704 705 if (pc->flags & PC_FLAG_DMA_OK) 706 drive->dma = !ide_dma_prepare(drive, cmd); 707 708 if (!drive->dma) 709 pc->flags &= ~PC_FLAG_DMA_OK; 710 711 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD 712 : WAIT_TAPE_CMD; 713 } 714 715 ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma); 716 717 (void)do_rw_taskfile(drive, cmd); 718 719 if (drq_int) { 720 if (drive->dma) 721 drive->waiting_for_dma = 0; 722 hwif->expiry = expiry; 723 } 724 725 ide_execute_command(drive, cmd, ide_transfer_pc, timeout); 726 727 return drq_int ? ide_started : ide_transfer_pc(drive); 728} 729EXPORT_SYMBOL_GPL(ide_issue_pc); 730