linux/drivers/block/hd.c
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   1/*
   2 *  Copyright (C) 1991, 1992  Linus Torvalds
   3 *
   4 * This is the low-level hd interrupt support. It traverses the
   5 * request-list, using interrupts to jump between functions. As
   6 * all the functions are called within interrupts, we may not
   7 * sleep. Special care is recommended.
   8 *
   9 *  modified by Drew Eckhardt to check nr of hd's from the CMOS.
  10 *
  11 *  Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
  12 *  in the early extended-partition checks and added DM partitions
  13 *
  14 *  IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
  15 *  and general streamlining by Mark Lord.
  16 *
  17 *  Removed 99% of above. Use Mark's ide driver for those options.
  18 *  This is now a lightweight ST-506 driver. (Paul Gortmaker)
  19 *
  20 *  Modified 1995 Russell King for ARM processor.
  21 *
  22 *  Bugfix: max_sectors must be <= 255 or the wheels tend to come
  23 *  off in a hurry once you queue things up - Paul G. 02/2001
  24 */
  25
  26/* Uncomment the following if you want verbose error reports. */
  27/* #define VERBOSE_ERRORS */
  28
  29#include <linux/blkdev.h>
  30#include <linux/errno.h>
  31#include <linux/signal.h>
  32#include <linux/interrupt.h>
  33#include <linux/timer.h>
  34#include <linux/fs.h>
  35#include <linux/kernel.h>
  36#include <linux/genhd.h>
  37#include <linux/string.h>
  38#include <linux/ioport.h>
  39#include <linux/init.h>
  40#include <linux/blkpg.h>
  41#include <linux/ata.h>
  42#include <linux/hdreg.h>
  43
  44#define HD_IRQ 14
  45
  46#define REALLY_SLOW_IO
  47#include <asm/io.h>
  48#include <asm/uaccess.h>
  49
  50#ifdef __arm__
  51#undef  HD_IRQ
  52#endif
  53#include <asm/irq.h>
  54#ifdef __arm__
  55#define HD_IRQ IRQ_HARDDISK
  56#endif
  57
  58/* Hd controller regster ports */
  59
  60#define HD_DATA         0x1f0           /* _CTL when writing */
  61#define HD_ERROR        0x1f1           /* see err-bits */
  62#define HD_NSECTOR      0x1f2           /* nr of sectors to read/write */
  63#define HD_SECTOR       0x1f3           /* starting sector */
  64#define HD_LCYL         0x1f4           /* starting cylinder */
  65#define HD_HCYL         0x1f5           /* high byte of starting cyl */
  66#define HD_CURRENT      0x1f6           /* 101dhhhh , d=drive, hhhh=head */
  67#define HD_STATUS       0x1f7           /* see status-bits */
  68#define HD_FEATURE      HD_ERROR        /* same io address, read=error, write=feature */
  69#define HD_PRECOMP      HD_FEATURE      /* obsolete use of this port - predates IDE */
  70#define HD_COMMAND      HD_STATUS       /* same io address, read=status, write=cmd */
  71
  72#define HD_CMD          0x3f6           /* used for resets */
  73#define HD_ALTSTATUS    0x3f6           /* same as HD_STATUS but doesn't clear irq */
  74
  75/* Bits of HD_STATUS */
  76#define ERR_STAT                0x01
  77#define INDEX_STAT              0x02
  78#define ECC_STAT                0x04    /* Corrected error */
  79#define DRQ_STAT                0x08
  80#define SEEK_STAT               0x10
  81#define SERVICE_STAT            SEEK_STAT
  82#define WRERR_STAT              0x20
  83#define READY_STAT              0x40
  84#define BUSY_STAT               0x80
  85
  86/* Bits for HD_ERROR */
  87#define MARK_ERR                0x01    /* Bad address mark */
  88#define TRK0_ERR                0x02    /* couldn't find track 0 */
  89#define ABRT_ERR                0x04    /* Command aborted */
  90#define MCR_ERR                 0x08    /* media change request */
  91#define ID_ERR                  0x10    /* ID field not found */
  92#define MC_ERR                  0x20    /* media changed */
  93#define ECC_ERR                 0x40    /* Uncorrectable ECC error */
  94#define BBD_ERR                 0x80    /* pre-EIDE meaning:  block marked bad */
  95#define ICRC_ERR                0x80    /* new meaning:  CRC error during transfer */
  96
  97static DEFINE_SPINLOCK(hd_lock);
  98static struct request_queue *hd_queue;
  99static struct request *hd_req;
 100
 101#define TIMEOUT_VALUE   (6*HZ)
 102#define HD_DELAY        0
 103
 104#define MAX_ERRORS     16       /* Max read/write errors/sector */
 105#define RESET_FREQ      8       /* Reset controller every 8th retry */
 106#define RECAL_FREQ      4       /* Recalibrate every 4th retry */
 107#define MAX_HD          2
 108
 109#define STAT_OK         (READY_STAT|SEEK_STAT)
 110#define OK_STATUS(s)    (((s)&(STAT_OK|(BUSY_STAT|WRERR_STAT|ERR_STAT)))==STAT_OK)
 111
 112static void recal_intr(void);
 113static void bad_rw_intr(void);
 114
 115static int reset;
 116static int hd_error;
 117
 118/*
 119 *  This struct defines the HD's and their types.
 120 */
 121struct hd_i_struct {
 122        unsigned int head, sect, cyl, wpcom, lzone, ctl;
 123        int unit;
 124        int recalibrate;
 125        int special_op;
 126};
 127
 128#ifdef HD_TYPE
 129static struct hd_i_struct hd_info[] = { HD_TYPE };
 130static int NR_HD = ARRAY_SIZE(hd_info);
 131#else
 132static struct hd_i_struct hd_info[MAX_HD];
 133static int NR_HD;
 134#endif
 135
 136static struct gendisk *hd_gendisk[MAX_HD];
 137
 138static struct timer_list device_timer;
 139
 140#define TIMEOUT_VALUE (6*HZ)
 141
 142#define SET_TIMER                                                       \
 143        do {                                                            \
 144                mod_timer(&device_timer, jiffies + TIMEOUT_VALUE);      \
 145        } while (0)
 146
 147static void (*do_hd)(void) = NULL;
 148#define SET_HANDLER(x) \
 149if ((do_hd = (x)) != NULL) \
 150        SET_TIMER; \
 151else \
 152        del_timer(&device_timer);
 153
 154
 155#if (HD_DELAY > 0)
 156
 157#include <linux/i8253.h>
 158
 159unsigned long last_req;
 160
 161unsigned long read_timer(void)
 162{
 163        unsigned long t, flags;
 164        int i;
 165
 166        raw_spin_lock_irqsave(&i8253_lock, flags);
 167        t = jiffies * 11932;
 168        outb_p(0, 0x43);
 169        i = inb_p(0x40);
 170        i |= inb(0x40) << 8;
 171        raw_spin_unlock_irqrestore(&i8253_lock, flags);
 172        return(t - i);
 173}
 174#endif
 175
 176static void __init hd_setup(char *str, int *ints)
 177{
 178        int hdind = 0;
 179
 180        if (ints[0] != 3)
 181                return;
 182        if (hd_info[0].head != 0)
 183                hdind = 1;
 184        hd_info[hdind].head = ints[2];
 185        hd_info[hdind].sect = ints[3];
 186        hd_info[hdind].cyl = ints[1];
 187        hd_info[hdind].wpcom = 0;
 188        hd_info[hdind].lzone = ints[1];
 189        hd_info[hdind].ctl = (ints[2] > 8 ? 8 : 0);
 190        NR_HD = hdind+1;
 191}
 192
 193static bool hd_end_request(int err, unsigned int bytes)
 194{
 195        if (__blk_end_request(hd_req, err, bytes))
 196                return true;
 197        hd_req = NULL;
 198        return false;
 199}
 200
 201static bool hd_end_request_cur(int err)
 202{
 203        return hd_end_request(err, blk_rq_cur_bytes(hd_req));
 204}
 205
 206static void dump_status(const char *msg, unsigned int stat)
 207{
 208        char *name = "hd?";
 209        if (hd_req)
 210                name = hd_req->rq_disk->disk_name;
 211
 212#ifdef VERBOSE_ERRORS
 213        printk("%s: %s: status=0x%02x { ", name, msg, stat & 0xff);
 214        if (stat & BUSY_STAT)   printk("Busy ");
 215        if (stat & READY_STAT)  printk("DriveReady ");
 216        if (stat & WRERR_STAT)  printk("WriteFault ");
 217        if (stat & SEEK_STAT)   printk("SeekComplete ");
 218        if (stat & DRQ_STAT)    printk("DataRequest ");
 219        if (stat & ECC_STAT)    printk("CorrectedError ");
 220        if (stat & INDEX_STAT)  printk("Index ");
 221        if (stat & ERR_STAT)    printk("Error ");
 222        printk("}\n");
 223        if ((stat & ERR_STAT) == 0) {
 224                hd_error = 0;
 225        } else {
 226                hd_error = inb(HD_ERROR);
 227                printk("%s: %s: error=0x%02x { ", name, msg, hd_error & 0xff);
 228                if (hd_error & BBD_ERR)         printk("BadSector ");
 229                if (hd_error & ECC_ERR)         printk("UncorrectableError ");
 230                if (hd_error & ID_ERR)          printk("SectorIdNotFound ");
 231                if (hd_error & ABRT_ERR)        printk("DriveStatusError ");
 232                if (hd_error & TRK0_ERR)        printk("TrackZeroNotFound ");
 233                if (hd_error & MARK_ERR)        printk("AddrMarkNotFound ");
 234                printk("}");
 235                if (hd_error & (BBD_ERR|ECC_ERR|ID_ERR|MARK_ERR)) {
 236                        printk(", CHS=%d/%d/%d", (inb(HD_HCYL)<<8) + inb(HD_LCYL),
 237                                inb(HD_CURRENT) & 0xf, inb(HD_SECTOR));
 238                        if (hd_req)
 239                                printk(", sector=%ld", blk_rq_pos(hd_req));
 240                }
 241                printk("\n");
 242        }
 243#else
 244        printk("%s: %s: status=0x%02x.\n", name, msg, stat & 0xff);
 245        if ((stat & ERR_STAT) == 0) {
 246                hd_error = 0;
 247        } else {
 248                hd_error = inb(HD_ERROR);
 249                printk("%s: %s: error=0x%02x.\n", name, msg, hd_error & 0xff);
 250        }
 251#endif
 252}
 253
 254static void check_status(void)
 255{
 256        int i = inb_p(HD_STATUS);
 257
 258        if (!OK_STATUS(i)) {
 259                dump_status("check_status", i);
 260                bad_rw_intr();
 261        }
 262}
 263
 264static int controller_busy(void)
 265{
 266        int retries = 100000;
 267        unsigned char status;
 268
 269        do {
 270                status = inb_p(HD_STATUS);
 271        } while ((status & BUSY_STAT) && --retries);
 272        return status;
 273}
 274
 275static int status_ok(void)
 276{
 277        unsigned char status = inb_p(HD_STATUS);
 278
 279        if (status & BUSY_STAT)
 280                return 1;       /* Ancient, but does it make sense??? */
 281        if (status & WRERR_STAT)
 282                return 0;
 283        if (!(status & READY_STAT))
 284                return 0;
 285        if (!(status & SEEK_STAT))
 286                return 0;
 287        return 1;
 288}
 289
 290static int controller_ready(unsigned int drive, unsigned int head)
 291{
 292        int retry = 100;
 293
 294        do {
 295                if (controller_busy() & BUSY_STAT)
 296                        return 0;
 297                outb_p(0xA0 | (drive<<4) | head, HD_CURRENT);
 298                if (status_ok())
 299                        return 1;
 300        } while (--retry);
 301        return 0;
 302}
 303
 304static void hd_out(struct hd_i_struct *disk,
 305                   unsigned int nsect,
 306                   unsigned int sect,
 307                   unsigned int head,
 308                   unsigned int cyl,
 309                   unsigned int cmd,
 310                   void (*intr_addr)(void))
 311{
 312        unsigned short port;
 313
 314#if (HD_DELAY > 0)
 315        while (read_timer() - last_req < HD_DELAY)
 316                /* nothing */;
 317#endif
 318        if (reset)
 319                return;
 320        if (!controller_ready(disk->unit, head)) {
 321                reset = 1;
 322                return;
 323        }
 324        SET_HANDLER(intr_addr);
 325        outb_p(disk->ctl, HD_CMD);
 326        port = HD_DATA;
 327        outb_p(disk->wpcom >> 2, ++port);
 328        outb_p(nsect, ++port);
 329        outb_p(sect, ++port);
 330        outb_p(cyl, ++port);
 331        outb_p(cyl >> 8, ++port);
 332        outb_p(0xA0 | (disk->unit << 4) | head, ++port);
 333        outb_p(cmd, ++port);
 334}
 335
 336static void hd_request (void);
 337
 338static int drive_busy(void)
 339{
 340        unsigned int i;
 341        unsigned char c;
 342
 343        for (i = 0; i < 500000 ; i++) {
 344                c = inb_p(HD_STATUS);
 345                if ((c & (BUSY_STAT | READY_STAT | SEEK_STAT)) == STAT_OK)
 346                        return 0;
 347        }
 348        dump_status("reset timed out", c);
 349        return 1;
 350}
 351
 352static void reset_controller(void)
 353{
 354        int     i;
 355
 356        outb_p(4, HD_CMD);
 357        for (i = 0; i < 1000; i++) barrier();
 358        outb_p(hd_info[0].ctl & 0x0f, HD_CMD);
 359        for (i = 0; i < 1000; i++) barrier();
 360        if (drive_busy())
 361                printk("hd: controller still busy\n");
 362        else if ((hd_error = inb(HD_ERROR)) != 1)
 363                printk("hd: controller reset failed: %02x\n", hd_error);
 364}
 365
 366static void reset_hd(void)
 367{
 368        static int i;
 369
 370repeat:
 371        if (reset) {
 372                reset = 0;
 373                i = -1;
 374                reset_controller();
 375        } else {
 376                check_status();
 377                if (reset)
 378                        goto repeat;
 379        }
 380        if (++i < NR_HD) {
 381                struct hd_i_struct *disk = &hd_info[i];
 382                disk->special_op = disk->recalibrate = 1;
 383                hd_out(disk, disk->sect, disk->sect, disk->head-1,
 384                        disk->cyl, ATA_CMD_INIT_DEV_PARAMS, &reset_hd);
 385                if (reset)
 386                        goto repeat;
 387        } else
 388                hd_request();
 389}
 390
 391/*
 392 * Ok, don't know what to do with the unexpected interrupts: on some machines
 393 * doing a reset and a retry seems to result in an eternal loop. Right now I
 394 * ignore it, and just set the timeout.
 395 *
 396 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
 397 * drive enters "idle", "standby", or "sleep" mode, so if the status looks
 398 * "good", we just ignore the interrupt completely.
 399 */
 400static void unexpected_hd_interrupt(void)
 401{
 402        unsigned int stat = inb_p(HD_STATUS);
 403
 404        if (stat & (BUSY_STAT|DRQ_STAT|ECC_STAT|ERR_STAT)) {
 405                dump_status("unexpected interrupt", stat);
 406                SET_TIMER;
 407        }
 408}
 409
 410/*
 411 * bad_rw_intr() now tries to be a bit smarter and does things
 412 * according to the error returned by the controller.
 413 * -Mika Liljeberg (liljeber@cs.Helsinki.FI)
 414 */
 415static void bad_rw_intr(void)
 416{
 417        struct request *req = hd_req;
 418
 419        if (req != NULL) {
 420                struct hd_i_struct *disk = req->rq_disk->private_data;
 421                if (++req->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) {
 422                        hd_end_request_cur(-EIO);
 423                        disk->special_op = disk->recalibrate = 1;
 424                } else if (req->errors % RESET_FREQ == 0)
 425                        reset = 1;
 426                else if ((hd_error & TRK0_ERR) || req->errors % RECAL_FREQ == 0)
 427                        disk->special_op = disk->recalibrate = 1;
 428                /* Otherwise just retry */
 429        }
 430}
 431
 432static inline int wait_DRQ(void)
 433{
 434        int retries;
 435        int stat;
 436
 437        for (retries = 0; retries < 100000; retries++) {
 438                stat = inb_p(HD_STATUS);
 439                if (stat & DRQ_STAT)
 440                        return 0;
 441        }
 442        dump_status("wait_DRQ", stat);
 443        return -1;
 444}
 445
 446static void read_intr(void)
 447{
 448        struct request *req;
 449        int i, retries = 100000;
 450
 451        do {
 452                i = (unsigned) inb_p(HD_STATUS);
 453                if (i & BUSY_STAT)
 454                        continue;
 455                if (!OK_STATUS(i))
 456                        break;
 457                if (i & DRQ_STAT)
 458                        goto ok_to_read;
 459        } while (--retries > 0);
 460        dump_status("read_intr", i);
 461        bad_rw_intr();
 462        hd_request();
 463        return;
 464
 465ok_to_read:
 466        req = hd_req;
 467        insw(HD_DATA, bio_data(req->bio), 256);
 468#ifdef DEBUG
 469        printk("%s: read: sector %ld, remaining = %u, buffer=%p\n",
 470               req->rq_disk->disk_name, blk_rq_pos(req) + 1,
 471               blk_rq_sectors(req) - 1, bio_data(req->bio)+512);
 472#endif
 473        if (hd_end_request(0, 512)) {
 474                SET_HANDLER(&read_intr);
 475                return;
 476        }
 477
 478        (void) inb_p(HD_STATUS);
 479#if (HD_DELAY > 0)
 480        last_req = read_timer();
 481#endif
 482        hd_request();
 483}
 484
 485static void write_intr(void)
 486{
 487        struct request *req = hd_req;
 488        int i;
 489        int retries = 100000;
 490
 491        do {
 492                i = (unsigned) inb_p(HD_STATUS);
 493                if (i & BUSY_STAT)
 494                        continue;
 495                if (!OK_STATUS(i))
 496                        break;
 497                if ((blk_rq_sectors(req) <= 1) || (i & DRQ_STAT))
 498                        goto ok_to_write;
 499        } while (--retries > 0);
 500        dump_status("write_intr", i);
 501        bad_rw_intr();
 502        hd_request();
 503        return;
 504
 505ok_to_write:
 506        if (hd_end_request(0, 512)) {
 507                SET_HANDLER(&write_intr);
 508                outsw(HD_DATA, bio_data(req->bio), 256);
 509                return;
 510        }
 511
 512#if (HD_DELAY > 0)
 513        last_req = read_timer();
 514#endif
 515        hd_request();
 516}
 517
 518static void recal_intr(void)
 519{
 520        check_status();
 521#if (HD_DELAY > 0)
 522        last_req = read_timer();
 523#endif
 524        hd_request();
 525}
 526
 527/*
 528 * This is another of the error-routines I don't know what to do with. The
 529 * best idea seems to just set reset, and start all over again.
 530 */
 531static void hd_times_out(unsigned long dummy)
 532{
 533        char *name;
 534
 535        do_hd = NULL;
 536
 537        if (!hd_req)
 538                return;
 539
 540        spin_lock_irq(hd_queue->queue_lock);
 541        reset = 1;
 542        name = hd_req->rq_disk->disk_name;
 543        printk("%s: timeout\n", name);
 544        if (++hd_req->errors >= MAX_ERRORS) {
 545#ifdef DEBUG
 546                printk("%s: too many errors\n", name);
 547#endif
 548                hd_end_request_cur(-EIO);
 549        }
 550        hd_request();
 551        spin_unlock_irq(hd_queue->queue_lock);
 552}
 553
 554static int do_special_op(struct hd_i_struct *disk, struct request *req)
 555{
 556        if (disk->recalibrate) {
 557                disk->recalibrate = 0;
 558                hd_out(disk, disk->sect, 0, 0, 0, ATA_CMD_RESTORE, &recal_intr);
 559                return reset;
 560        }
 561        if (disk->head > 16) {
 562                printk("%s: cannot handle device with more than 16 heads - giving up\n", req->rq_disk->disk_name);
 563                hd_end_request_cur(-EIO);
 564        }
 565        disk->special_op = 0;
 566        return 1;
 567}
 568
 569/*
 570 * The driver enables interrupts as much as possible.  In order to do this,
 571 * (a) the device-interrupt is disabled before entering hd_request(),
 572 * and (b) the timeout-interrupt is disabled before the sti().
 573 *
 574 * Interrupts are still masked (by default) whenever we are exchanging
 575 * data/cmds with a drive, because some drives seem to have very poor
 576 * tolerance for latency during I/O. The IDE driver has support to unmask
 577 * interrupts for non-broken hardware, so use that driver if required.
 578 */
 579static void hd_request(void)
 580{
 581        unsigned int block, nsect, sec, track, head, cyl;
 582        struct hd_i_struct *disk;
 583        struct request *req;
 584
 585        if (do_hd)
 586                return;
 587repeat:
 588        del_timer(&device_timer);
 589
 590        if (!hd_req) {
 591                hd_req = blk_fetch_request(hd_queue);
 592                if (!hd_req) {
 593                        do_hd = NULL;
 594                        return;
 595                }
 596        }
 597        req = hd_req;
 598
 599        if (reset) {
 600                reset_hd();
 601                return;
 602        }
 603        disk = req->rq_disk->private_data;
 604        block = blk_rq_pos(req);
 605        nsect = blk_rq_sectors(req);
 606        if (block >= get_capacity(req->rq_disk) ||
 607            ((block+nsect) > get_capacity(req->rq_disk))) {
 608                printk("%s: bad access: block=%d, count=%d\n",
 609                        req->rq_disk->disk_name, block, nsect);
 610                hd_end_request_cur(-EIO);
 611                goto repeat;
 612        }
 613
 614        if (disk->special_op) {
 615                if (do_special_op(disk, req))
 616                        goto repeat;
 617                return;
 618        }
 619        sec   = block % disk->sect + 1;
 620        track = block / disk->sect;
 621        head  = track % disk->head;
 622        cyl   = track / disk->head;
 623#ifdef DEBUG
 624        printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
 625                req->rq_disk->disk_name,
 626                req_data_dir(req) == READ ? "read" : "writ",
 627                cyl, head, sec, nsect, bio_data(req->bio));
 628#endif
 629        if (req->cmd_type == REQ_TYPE_FS) {
 630                switch (rq_data_dir(req)) {
 631                case READ:
 632                        hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_READ,
 633                                &read_intr);
 634                        if (reset)
 635                                goto repeat;
 636                        break;
 637                case WRITE:
 638                        hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_WRITE,
 639                                &write_intr);
 640                        if (reset)
 641                                goto repeat;
 642                        if (wait_DRQ()) {
 643                                bad_rw_intr();
 644                                goto repeat;
 645                        }
 646                        outsw(HD_DATA, bio_data(req->bio), 256);
 647                        break;
 648                default:
 649                        printk("unknown hd-command\n");
 650                        hd_end_request_cur(-EIO);
 651                        break;
 652                }
 653        }
 654}
 655
 656static void do_hd_request(struct request_queue *q)
 657{
 658        hd_request();
 659}
 660
 661static int hd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 662{
 663        struct hd_i_struct *disk = bdev->bd_disk->private_data;
 664
 665        geo->heads = disk->head;
 666        geo->sectors = disk->sect;
 667        geo->cylinders = disk->cyl;
 668        return 0;
 669}
 670
 671/*
 672 * Releasing a block device means we sync() it, so that it can safely
 673 * be forgotten about...
 674 */
 675
 676static irqreturn_t hd_interrupt(int irq, void *dev_id)
 677{
 678        void (*handler)(void) = do_hd;
 679
 680        spin_lock(hd_queue->queue_lock);
 681
 682        do_hd = NULL;
 683        del_timer(&device_timer);
 684        if (!handler)
 685                handler = unexpected_hd_interrupt;
 686        handler();
 687
 688        spin_unlock(hd_queue->queue_lock);
 689
 690        return IRQ_HANDLED;
 691}
 692
 693static const struct block_device_operations hd_fops = {
 694        .getgeo =       hd_getgeo,
 695};
 696
 697static int __init hd_init(void)
 698{
 699        int drive;
 700
 701        if (register_blkdev(HD_MAJOR, "hd"))
 702                return -1;
 703
 704        hd_queue = blk_init_queue(do_hd_request, &hd_lock);
 705        if (!hd_queue) {
 706                unregister_blkdev(HD_MAJOR, "hd");
 707                return -ENOMEM;
 708        }
 709
 710        blk_queue_max_hw_sectors(hd_queue, 255);
 711        init_timer(&device_timer);
 712        device_timer.function = hd_times_out;
 713        blk_queue_logical_block_size(hd_queue, 512);
 714
 715        if (!NR_HD) {
 716                /*
 717                 * We don't know anything about the drive.  This means
 718                 * that you *MUST* specify the drive parameters to the
 719                 * kernel yourself.
 720                 *
 721                 * If we were on an i386, we used to read this info from
 722                 * the BIOS or CMOS.  This doesn't work all that well,
 723                 * since this assumes that this is a primary or secondary
 724                 * drive, and if we're using this legacy driver, it's
 725                 * probably an auxiliary controller added to recover
 726                 * legacy data off an ST-506 drive.  Either way, it's
 727                 * definitely safest to have the user explicitly specify
 728                 * the information.
 729                 */
 730                printk("hd: no drives specified - use hd=cyl,head,sectors"
 731                        " on kernel command line\n");
 732                goto out;
 733        }
 734
 735        for (drive = 0 ; drive < NR_HD ; drive++) {
 736                struct gendisk *disk = alloc_disk(64);
 737                struct hd_i_struct *p = &hd_info[drive];
 738                if (!disk)
 739                        goto Enomem;
 740                disk->major = HD_MAJOR;
 741                disk->first_minor = drive << 6;
 742                disk->fops = &hd_fops;
 743                sprintf(disk->disk_name, "hd%c", 'a'+drive);
 744                disk->private_data = p;
 745                set_capacity(disk, p->head * p->sect * p->cyl);
 746                disk->queue = hd_queue;
 747                p->unit = drive;
 748                hd_gendisk[drive] = disk;
 749                printk("%s: %luMB, CHS=%d/%d/%d\n",
 750                        disk->disk_name, (unsigned long)get_capacity(disk)/2048,
 751                        p->cyl, p->head, p->sect);
 752        }
 753
 754        if (request_irq(HD_IRQ, hd_interrupt, 0, "hd", NULL)) {
 755                printk("hd: unable to get IRQ%d for the hard disk driver\n",
 756                        HD_IRQ);
 757                goto out1;
 758        }
 759        if (!request_region(HD_DATA, 8, "hd")) {
 760                printk(KERN_WARNING "hd: port 0x%x busy\n", HD_DATA);
 761                goto out2;
 762        }
 763        if (!request_region(HD_CMD, 1, "hd(cmd)")) {
 764                printk(KERN_WARNING "hd: port 0x%x busy\n", HD_CMD);
 765                goto out3;
 766        }
 767
 768        /* Let them fly */
 769        for (drive = 0; drive < NR_HD; drive++)
 770                add_disk(hd_gendisk[drive]);
 771
 772        return 0;
 773
 774out3:
 775        release_region(HD_DATA, 8);
 776out2:
 777        free_irq(HD_IRQ, NULL);
 778out1:
 779        for (drive = 0; drive < NR_HD; drive++)
 780                put_disk(hd_gendisk[drive]);
 781        NR_HD = 0;
 782out:
 783        del_timer(&device_timer);
 784        unregister_blkdev(HD_MAJOR, "hd");
 785        blk_cleanup_queue(hd_queue);
 786        return -1;
 787Enomem:
 788        while (drive--)
 789                put_disk(hd_gendisk[drive]);
 790        goto out;
 791}
 792
 793static int __init parse_hd_setup(char *line)
 794{
 795        int ints[6];
 796
 797        (void) get_options(line, ARRAY_SIZE(ints), ints);
 798        hd_setup(NULL, ints);
 799
 800        return 1;
 801}
 802__setup("hd=", parse_hd_setup);
 803
 804late_initcall(hd_init);
 805