linux/drivers/ide/legacy/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/slab.h>
  38#include <linux/string.h>
  39#include <linux/ioport.h>
  40#include <linux/mc146818rtc.h> /* CMOS defines */
  41#include <linux/init.h>
  42#include <linux/blkpg.h>
  43#include <linux/hdreg.h>
  44
  45#define REALLY_SLOW_IO
  46#include <asm/system.h>
  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;
  99
 100#define MAJOR_NR HD_MAJOR
 101#define QUEUE (hd_queue)
 102#define CURRENT elv_next_request(hd_queue)
 103
 104#define TIMEOUT_VALUE   (6*HZ)
 105#define HD_DELAY        0
 106
 107#define MAX_ERRORS     16       /* Max read/write errors/sector */
 108#define RESET_FREQ      8       /* Reset controller every 8th retry */
 109#define RECAL_FREQ      4       /* Recalibrate every 4th retry */
 110#define MAX_HD          2
 111
 112#define STAT_OK         (READY_STAT|SEEK_STAT)
 113#define OK_STATUS(s)    (((s)&(STAT_OK|(BUSY_STAT|WRERR_STAT|ERR_STAT)))==STAT_OK)
 114
 115static void recal_intr(void);
 116static void bad_rw_intr(void);
 117
 118static int reset;
 119static int hd_error;
 120
 121/*
 122 *  This struct defines the HD's and their types.
 123 */
 124struct hd_i_struct {
 125        unsigned int head,sect,cyl,wpcom,lzone,ctl;
 126        int unit;
 127        int recalibrate;
 128        int special_op;
 129};
 130        
 131#ifdef HD_TYPE
 132static struct hd_i_struct hd_info[] = { HD_TYPE };
 133static int NR_HD = ARRAY_SIZE(hd_info);
 134#else
 135static struct hd_i_struct hd_info[MAX_HD];
 136static int NR_HD;
 137#endif
 138
 139static struct gendisk *hd_gendisk[MAX_HD];
 140
 141static struct timer_list device_timer;
 142
 143#define TIMEOUT_VALUE (6*HZ)
 144
 145#define SET_TIMER                                                       \
 146        do {                                                            \
 147                mod_timer(&device_timer, jiffies + TIMEOUT_VALUE);      \
 148        } while (0)
 149
 150static void (*do_hd)(void) = NULL;
 151#define SET_HANDLER(x) \
 152if ((do_hd = (x)) != NULL) \
 153        SET_TIMER; \
 154else \
 155        del_timer(&device_timer);
 156
 157
 158#if (HD_DELAY > 0)
 159
 160#include <asm/i8253.h>
 161
 162unsigned long last_req;
 163
 164unsigned long read_timer(void)
 165{
 166        unsigned long t, flags;
 167        int i;
 168
 169        spin_lock_irqsave(&i8253_lock, flags);
 170        t = jiffies * 11932;
 171        outb_p(0, 0x43);
 172        i = inb_p(0x40);
 173        i |= inb(0x40) << 8;
 174        spin_unlock_irqrestore(&i8253_lock, flags);
 175        return(t - i);
 176}
 177#endif
 178
 179static void __init hd_setup(char *str, int *ints)
 180{
 181        int hdind = 0;
 182
 183        if (ints[0] != 3)
 184                return;
 185        if (hd_info[0].head != 0)
 186                hdind=1;
 187        hd_info[hdind].head = ints[2];
 188        hd_info[hdind].sect = ints[3];
 189        hd_info[hdind].cyl = ints[1];
 190        hd_info[hdind].wpcom = 0;
 191        hd_info[hdind].lzone = ints[1];
 192        hd_info[hdind].ctl = (ints[2] > 8 ? 8 : 0);
 193        NR_HD = hdind+1;
 194}
 195
 196static void dump_status (const char *msg, unsigned int stat)
 197{
 198        char *name = "hd?";
 199        if (CURRENT)
 200                name = CURRENT->rq_disk->disk_name;
 201
 202#ifdef VERBOSE_ERRORS
 203        printk("%s: %s: status=0x%02x { ", name, msg, stat & 0xff);
 204        if (stat & BUSY_STAT)   printk("Busy ");
 205        if (stat & READY_STAT)  printk("DriveReady ");
 206        if (stat & WRERR_STAT)  printk("WriteFault ");
 207        if (stat & SEEK_STAT)   printk("SeekComplete ");
 208        if (stat & DRQ_STAT)    printk("DataRequest ");
 209        if (stat & ECC_STAT)    printk("CorrectedError ");
 210        if (stat & INDEX_STAT)  printk("Index ");
 211        if (stat & ERR_STAT)    printk("Error ");
 212        printk("}\n");
 213        if ((stat & ERR_STAT) == 0) {
 214                hd_error = 0;
 215        } else {
 216                hd_error = inb(HD_ERROR);
 217                printk("%s: %s: error=0x%02x { ", name, msg, hd_error & 0xff);
 218                if (hd_error & BBD_ERR)         printk("BadSector ");
 219                if (hd_error & ECC_ERR)         printk("UncorrectableError ");
 220                if (hd_error & ID_ERR)          printk("SectorIdNotFound ");
 221                if (hd_error & ABRT_ERR)        printk("DriveStatusError ");
 222                if (hd_error & TRK0_ERR)        printk("TrackZeroNotFound ");
 223                if (hd_error & MARK_ERR)        printk("AddrMarkNotFound ");
 224                printk("}");
 225                if (hd_error & (BBD_ERR|ECC_ERR|ID_ERR|MARK_ERR)) {
 226                        printk(", CHS=%d/%d/%d", (inb(HD_HCYL)<<8) + inb(HD_LCYL),
 227                                inb(HD_CURRENT) & 0xf, inb(HD_SECTOR));
 228                        if (CURRENT)
 229                                printk(", sector=%ld", CURRENT->sector);
 230                }
 231                printk("\n");
 232        }
 233#else
 234        printk("%s: %s: status=0x%02x.\n", name, msg, stat & 0xff);
 235        if ((stat & ERR_STAT) == 0) {
 236                hd_error = 0;
 237        } else {
 238                hd_error = inb(HD_ERROR);
 239                printk("%s: %s: error=0x%02x.\n", name, msg, hd_error & 0xff);
 240        }
 241#endif
 242}
 243
 244static void check_status(void)
 245{
 246        int i = inb_p(HD_STATUS);
 247
 248        if (!OK_STATUS(i)) {
 249                dump_status("check_status", i);
 250                bad_rw_intr();
 251        }
 252}
 253
 254static int controller_busy(void)
 255{
 256        int retries = 100000;
 257        unsigned char status;
 258
 259        do {
 260                status = inb_p(HD_STATUS);
 261        } while ((status & BUSY_STAT) && --retries);
 262        return status;
 263}
 264
 265static int status_ok(void)
 266{
 267        unsigned char status = inb_p(HD_STATUS);
 268
 269        if (status & BUSY_STAT)
 270                return 1;       /* Ancient, but does it make sense??? */
 271        if (status & WRERR_STAT)
 272                return 0;
 273        if (!(status & READY_STAT))
 274                return 0;
 275        if (!(status & SEEK_STAT))
 276                return 0;
 277        return 1;
 278}
 279
 280static int controller_ready(unsigned int drive, unsigned int head)
 281{
 282        int retry = 100;
 283
 284        do {
 285                if (controller_busy() & BUSY_STAT)
 286                        return 0;
 287                outb_p(0xA0 | (drive<<4) | head, HD_CURRENT);
 288                if (status_ok())
 289                        return 1;
 290        } while (--retry);
 291        return 0;
 292}
 293
 294                
 295static void hd_out(struct hd_i_struct *disk,
 296                   unsigned int nsect,
 297                   unsigned int sect,
 298                   unsigned int head,
 299                   unsigned int cyl,
 300                   unsigned int cmd,
 301                   void (*intr_addr)(void))
 302{
 303        unsigned short port;
 304
 305#if (HD_DELAY > 0)
 306        while (read_timer() - last_req < HD_DELAY)
 307                /* nothing */;
 308#endif
 309        if (reset)
 310                return;
 311        if (!controller_ready(disk->unit, head)) {
 312                reset = 1;
 313                return;
 314        }
 315        SET_HANDLER(intr_addr);
 316        outb_p(disk->ctl,HD_CMD);
 317        port=HD_DATA;
 318        outb_p(disk->wpcom>>2,++port);
 319        outb_p(nsect,++port);
 320        outb_p(sect,++port);
 321        outb_p(cyl,++port);
 322        outb_p(cyl>>8,++port);
 323        outb_p(0xA0|(disk->unit<<4)|head,++port);
 324        outb_p(cmd,++port);
 325}
 326
 327static void hd_request (void);
 328
 329static int drive_busy(void)
 330{
 331        unsigned int i;
 332        unsigned char c;
 333
 334        for (i = 0; i < 500000 ; i++) {
 335                c = inb_p(HD_STATUS);
 336                if ((c & (BUSY_STAT | READY_STAT | SEEK_STAT)) == STAT_OK)
 337                        return 0;
 338        }
 339        dump_status("reset timed out", c);
 340        return 1;
 341}
 342
 343static void reset_controller(void)
 344{
 345        int     i;
 346
 347        outb_p(4,HD_CMD);
 348        for(i = 0; i < 1000; i++) barrier();
 349        outb_p(hd_info[0].ctl & 0x0f,HD_CMD);
 350        for(i = 0; i < 1000; i++) barrier();
 351        if (drive_busy())
 352                printk("hd: controller still busy\n");
 353        else if ((hd_error = inb(HD_ERROR)) != 1)
 354                printk("hd: controller reset failed: %02x\n",hd_error);
 355}
 356
 357static void reset_hd(void)
 358{
 359        static int i;
 360
 361repeat:
 362        if (reset) {
 363                reset = 0;
 364                i = -1;
 365                reset_controller();
 366        } else {
 367                check_status();
 368                if (reset)
 369                        goto repeat;
 370        }
 371        if (++i < NR_HD) {
 372                struct hd_i_struct *disk = &hd_info[i];
 373                disk->special_op = disk->recalibrate = 1;
 374                hd_out(disk,disk->sect,disk->sect,disk->head-1,
 375                        disk->cyl,WIN_SPECIFY,&reset_hd);
 376                if (reset)
 377                        goto repeat;
 378        } else
 379                hd_request();
 380}
 381
 382/*
 383 * Ok, don't know what to do with the unexpected interrupts: on some machines
 384 * doing a reset and a retry seems to result in an eternal loop. Right now I
 385 * ignore it, and just set the timeout.
 386 *
 387 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
 388 * drive enters "idle", "standby", or "sleep" mode, so if the status looks
 389 * "good", we just ignore the interrupt completely.
 390 */
 391static void unexpected_hd_interrupt(void)
 392{
 393        unsigned int stat = inb_p(HD_STATUS);
 394
 395        if (stat & (BUSY_STAT|DRQ_STAT|ECC_STAT|ERR_STAT)) {
 396                dump_status ("unexpected interrupt", stat);
 397                SET_TIMER;
 398        }
 399}
 400
 401/*
 402 * bad_rw_intr() now tries to be a bit smarter and does things
 403 * according to the error returned by the controller.
 404 * -Mika Liljeberg (liljeber@cs.Helsinki.FI)
 405 */
 406static void bad_rw_intr(void)
 407{
 408        struct request *req = CURRENT;
 409        if (req != NULL) {
 410                struct hd_i_struct *disk = req->rq_disk->private_data;
 411                if (++req->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) {
 412                        end_request(req, 0);
 413                        disk->special_op = disk->recalibrate = 1;
 414                } else if (req->errors % RESET_FREQ == 0)
 415                        reset = 1;
 416                else if ((hd_error & TRK0_ERR) || req->errors % RECAL_FREQ == 0)
 417                        disk->special_op = disk->recalibrate = 1;
 418                /* Otherwise just retry */
 419        }
 420}
 421
 422static inline int wait_DRQ(void)
 423{
 424        int retries = 100000, stat;
 425
 426        while (--retries > 0)
 427                if ((stat = inb_p(HD_STATUS)) & DRQ_STAT)
 428                        return 0;
 429        dump_status("wait_DRQ", stat);
 430        return -1;
 431}
 432
 433static void read_intr(void)
 434{
 435        struct request *req;
 436        int i, retries = 100000;
 437
 438        do {
 439                i = (unsigned) inb_p(HD_STATUS);
 440                if (i & BUSY_STAT)
 441                        continue;
 442                if (!OK_STATUS(i))
 443                        break;
 444                if (i & DRQ_STAT)
 445                        goto ok_to_read;
 446        } while (--retries > 0);
 447        dump_status("read_intr", i);
 448        bad_rw_intr();
 449        hd_request();
 450        return;
 451ok_to_read:
 452        req = CURRENT;
 453        insw(HD_DATA,req->buffer,256);
 454        req->sector++;
 455        req->buffer += 512;
 456        req->errors = 0;
 457        i = --req->nr_sectors;
 458        --req->current_nr_sectors;
 459#ifdef DEBUG
 460        printk("%s: read: sector %ld, remaining = %ld, buffer=%p\n",
 461                req->rq_disk->disk_name, req->sector, req->nr_sectors,
 462                req->buffer+512);
 463#endif
 464        if (req->current_nr_sectors <= 0)
 465                end_request(req, 1);
 466        if (i > 0) {
 467                SET_HANDLER(&read_intr);
 468                return;
 469        }
 470        (void) inb_p(HD_STATUS);
 471#if (HD_DELAY > 0)
 472        last_req = read_timer();
 473#endif
 474        if (elv_next_request(QUEUE))
 475                hd_request();
 476        return;
 477}
 478
 479static void write_intr(void)
 480{
 481        struct request *req = CURRENT;
 482        int i;
 483        int retries = 100000;
 484
 485        do {
 486                i = (unsigned) inb_p(HD_STATUS);
 487                if (i & BUSY_STAT)
 488                        continue;
 489                if (!OK_STATUS(i))
 490                        break;
 491                if ((req->nr_sectors <= 1) || (i & DRQ_STAT))
 492                        goto ok_to_write;
 493        } while (--retries > 0);
 494        dump_status("write_intr", i);
 495        bad_rw_intr();
 496        hd_request();
 497        return;
 498ok_to_write:
 499        req->sector++;
 500        i = --req->nr_sectors;
 501        --req->current_nr_sectors;
 502        req->buffer += 512;
 503        if (!i || (req->bio && req->current_nr_sectors <= 0))
 504                end_request(req, 1);
 505        if (i > 0) {
 506                SET_HANDLER(&write_intr);
 507                outsw(HD_DATA,req->buffer,256);
 508                local_irq_enable();
 509        } else {
 510#if (HD_DELAY > 0)
 511                last_req = read_timer();
 512#endif
 513                hd_request();
 514        }
 515        return;
 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 (!CURRENT)
 538                return;
 539
 540        disable_irq(HD_IRQ);
 541        local_irq_enable();
 542        reset = 1;
 543        name = CURRENT->rq_disk->disk_name;
 544        printk("%s: timeout\n", name);
 545        if (++CURRENT->errors >= MAX_ERRORS) {
 546#ifdef DEBUG
 547                printk("%s: too many errors\n", name);
 548#endif
 549                end_request(CURRENT, 0);
 550        }
 551        local_irq_disable();
 552        hd_request();
 553        enable_irq(HD_IRQ);
 554}
 555
 556static int do_special_op(struct hd_i_struct *disk, struct request *req)
 557{
 558        if (disk->recalibrate) {
 559                disk->recalibrate = 0;
 560                hd_out(disk,disk->sect,0,0,0,WIN_RESTORE,&recal_intr);
 561                return reset;
 562        }
 563        if (disk->head > 16) {
 564                printk ("%s: cannot handle device with more than 16 heads - giving up\n", req->rq_disk->disk_name);
 565                end_request(req, 0);
 566        }
 567        disk->special_op = 0;
 568        return 1;
 569}
 570
 571/*
 572 * The driver enables interrupts as much as possible.  In order to do this,
 573 * (a) the device-interrupt is disabled before entering hd_request(),
 574 * and (b) the timeout-interrupt is disabled before the sti().
 575 *
 576 * Interrupts are still masked (by default) whenever we are exchanging
 577 * data/cmds with a drive, because some drives seem to have very poor
 578 * tolerance for latency during I/O. The IDE driver has support to unmask
 579 * interrupts for non-broken hardware, so use that driver if required.
 580 */
 581static void hd_request(void)
 582{
 583        unsigned int block, nsect, sec, track, head, cyl;
 584        struct hd_i_struct *disk;
 585        struct request *req;
 586
 587        if (do_hd)
 588                return;
 589repeat:
 590        del_timer(&device_timer);
 591        local_irq_enable();
 592
 593        req = CURRENT;
 594        if (!req) {
 595                do_hd = NULL;
 596                return;
 597        }
 598
 599        if (reset) {
 600                local_irq_disable();
 601                reset_hd();
 602                return;
 603        }
 604        disk = req->rq_disk->private_data;
 605        block = req->sector;
 606        nsect = req->nr_sectors;
 607        if (block >= get_capacity(req->rq_disk) ||
 608            ((block+nsect) > get_capacity(req->rq_disk))) {
 609                printk("%s: bad access: block=%d, count=%d\n",
 610                        req->rq_disk->disk_name, block, nsect);
 611                end_request(req, 0);
 612                goto repeat;
 613        }
 614
 615        if (disk->special_op) {
 616                if (do_special_op(disk, req))
 617                        goto repeat;
 618                return;
 619        }
 620        sec   = block % disk->sect + 1;
 621        track = block / disk->sect;
 622        head  = track % disk->head;
 623        cyl   = track / disk->head;
 624#ifdef DEBUG
 625        printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
 626                req->rq_disk->disk_name,
 627                req_data_dir(req) == READ ? "read" : "writ",
 628                cyl, head, sec, nsect, req->buffer);
 629#endif
 630        if (blk_fs_request(req)) {
 631                switch (rq_data_dir(req)) {
 632                case READ:
 633                        hd_out(disk,nsect,sec,head,cyl,WIN_READ,&read_intr);
 634                        if (reset)
 635                                goto repeat;
 636                        break;
 637                case WRITE:
 638                        hd_out(disk,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
 639                        if (reset)
 640                                goto repeat;
 641                        if (wait_DRQ()) {
 642                                bad_rw_intr();
 643                                goto repeat;
 644                        }
 645                        outsw(HD_DATA,req->buffer,256);
 646                        break;
 647                default:
 648                        printk("unknown hd-command\n");
 649                        end_request(req, 0);
 650                        break;
 651                }
 652        }
 653}
 654
 655static void do_hd_request (struct request_queue * q)
 656{
 657        disable_irq(HD_IRQ);
 658        hd_request();
 659        enable_irq(HD_IRQ);
 660}
 661
 662static int hd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 663{
 664        struct hd_i_struct *disk = bdev->bd_disk->private_data;
 665
 666        geo->heads = disk->head;
 667        geo->sectors = disk->sect;
 668        geo->cylinders = disk->cyl;
 669        return 0;
 670}
 671
 672/*
 673 * Releasing a block device means we sync() it, so that it can safely
 674 * be forgotten about...
 675 */
 676
 677static irqreturn_t hd_interrupt(int irq, void *dev_id)
 678{
 679        void (*handler)(void) = do_hd;
 680
 681        do_hd = NULL;
 682        del_timer(&device_timer);
 683        if (!handler)
 684                handler = unexpected_hd_interrupt;
 685        handler();
 686        local_irq_enable();
 687        return IRQ_HANDLED;
 688}
 689
 690static struct block_device_operations hd_fops = {
 691        .getgeo =       hd_getgeo,
 692};
 693
 694/*
 695 * This is the hard disk IRQ description. The IRQF_DISABLED in sa_flags
 696 * means we run the IRQ-handler with interrupts disabled:  this is bad for
 697 * interrupt latency, but anything else has led to problems on some
 698 * machines.
 699 *
 700 * We enable interrupts in some of the routines after making sure it's
 701 * safe.
 702 */
 703
 704static int __init hd_init(void)
 705{
 706        int drive;
 707
 708        if (register_blkdev(MAJOR_NR,"hd"))
 709                return -1;
 710
 711        hd_queue = blk_init_queue(do_hd_request, &hd_lock);
 712        if (!hd_queue) {
 713                unregister_blkdev(MAJOR_NR,"hd");
 714                return -ENOMEM;
 715        }
 716
 717        blk_queue_max_sectors(hd_queue, 255);
 718        init_timer(&device_timer);
 719        device_timer.function = hd_times_out;
 720        blk_queue_hardsect_size(hd_queue, 512);
 721
 722        if (!NR_HD) {
 723                /*
 724                 * We don't know anything about the drive.  This means
 725                 * that you *MUST* specify the drive parameters to the
 726                 * kernel yourself.
 727                 *
 728                 * If we were on an i386, we used to read this info from
 729                 * the BIOS or CMOS.  This doesn't work all that well,
 730                 * since this assumes that this is a primary or secondary
 731                 * drive, and if we're using this legacy driver, it's
 732                 * probably an auxilliary controller added to recover
 733                 * legacy data off an ST-506 drive.  Either way, it's
 734                 * definitely safest to have the user explicitly specify
 735                 * the information.
 736                 */
 737                printk("hd: no drives specified - use hd=cyl,head,sectors"
 738                        " on kernel command line\n");
 739                goto out;
 740        }
 741
 742        for (drive=0 ; drive < NR_HD ; drive++) {
 743                struct gendisk *disk = alloc_disk(64);
 744                struct hd_i_struct *p = &hd_info[drive];
 745                if (!disk)
 746                        goto Enomem;
 747                disk->major = MAJOR_NR;
 748                disk->first_minor = drive << 6;
 749                disk->fops = &hd_fops;
 750                sprintf(disk->disk_name, "hd%c", 'a'+drive);
 751                disk->private_data = p;
 752                set_capacity(disk, p->head * p->sect * p->cyl);
 753                disk->queue = hd_queue;
 754                p->unit = drive;
 755                hd_gendisk[drive] = disk;
 756                printk ("%s: %luMB, CHS=%d/%d/%d\n",
 757                        disk->disk_name, (unsigned long)get_capacity(disk)/2048,
 758                        p->cyl, p->head, p->sect);
 759        }
 760
 761        if (request_irq(HD_IRQ, hd_interrupt, IRQF_DISABLED, "hd", NULL)) {
 762                printk("hd: unable to get IRQ%d for the hard disk driver\n",
 763                        HD_IRQ);
 764                goto out1;
 765        }
 766        if (!request_region(HD_DATA, 8, "hd")) {
 767                printk(KERN_WARNING "hd: port 0x%x busy\n", HD_DATA);
 768                goto out2;
 769        }
 770        if (!request_region(HD_CMD, 1, "hd(cmd)")) {
 771                printk(KERN_WARNING "hd: port 0x%x busy\n", HD_CMD);
 772                goto out3;
 773        }
 774
 775        /* Let them fly */
 776        for(drive=0; drive < NR_HD; drive++)
 777                add_disk(hd_gendisk[drive]);
 778
 779        return 0;
 780
 781out3:
 782        release_region(HD_DATA, 8);
 783out2:
 784        free_irq(HD_IRQ, NULL);
 785out1:
 786        for (drive = 0; drive < NR_HD; drive++)
 787                put_disk(hd_gendisk[drive]);
 788        NR_HD = 0;
 789out:
 790        del_timer(&device_timer);
 791        unregister_blkdev(MAJOR_NR,"hd");
 792        blk_cleanup_queue(hd_queue);
 793        return -1;
 794Enomem:
 795        while (drive--)
 796                put_disk(hd_gendisk[drive]);
 797        goto out;
 798}
 799
 800static int __init parse_hd_setup (char *line) {
 801        int ints[6];
 802
 803        (void) get_options(line, ARRAY_SIZE(ints), ints);
 804        hd_setup(NULL, ints);
 805
 806        return 1;
 807}
 808__setup("hd=", parse_hd_setup);
 809
 810module_init(hd_init);
 811
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