drivers/block/hd.c

/* */
This source file includes following definitions.
CMOS_READ
read_timer
hd_setup
dump_status
check_status
controller_busy
status_ok
controller_ready
hd_out
fixstring
identify_intr
set_multmode_intr
drive_busy
reset_controller
reset_hd
unexpected_hd_interrupt
bad_rw_intr
wait_DRQ
read_intr
multwrite
multwrite_intr
write_intr
recal_intr
hd_times_out
do_special_op
hd_request
do_hd_request
hd_ioctl
hd_open
hd_release
hd_interrupt
hd_geninit
hd_init
revalidate_hddisk
   1 /*
   2  *  linux/kernel/hd.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6 
   7 /*
   8  * This is the low-level hd interrupt support. It traverses the
   9  * request-list, using interrupts to jump between functions. As
  10  * all the functions are called within interrupts, we may not
  11  * sleep. Special care is recommended.
  12  * 
  13  *  modified by Drew Eckhardt to check nr of hd's from the CMOS.
  14  *
  15  *  Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
  16  *  in the early extended-partition checks and added DM partitions
  17  *
  18  *  IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
  19  *  and general streamlining by mlord@bnr.ca (Mark Lord).
  20  */
  21 
  22 #define DEFAULT_MULT_COUNT  0   /* set to 0 to disable multiple mode at boot */
  23 #define DEFAULT_UNMASK_INTR 0   /* set to 0 to *NOT* unmask irq's more often */
  24 
  25 #include <asm/irq.h>
  26 #include <linux/errno.h>
  27 #include <linux/signal.h>
  28 #include <linux/sched.h>
  29 #include <linux/timer.h>
  30 #include <linux/fs.h>
  31 #include <linux/kernel.h>
  32 #include <linux/hdreg.h>
  33 #include <linux/genhd.h>
  34 #include <linux/config.h>
  35 #include <linux/malloc.h>
  36 #include <linux/string.h>
  37 
  38 #define REALLY_SLOW_IO
  39 #include <asm/system.h>
  40 #include <asm/io.h>
  41 #include <asm/segment.h>
  42 
  43 #define MAJOR_NR HD_MAJOR
  44 #include "blk.h"
  45 
  46 #define HD_IRQ 14
  47 
  48 static int revalidate_hddisk(int, int);
  49 
  50 static inline unsigned char CMOS_READ(unsigned char addr)
     /*  */
  51 {
  52         outb_p(addr,0x70);
  53         return inb_p(0x71);
  54 }
  55 
  56 #define HD_DELAY        0
  57 
  58 #define MAX_ERRORS     16       /* Max read/write errors/sector */
  59 #define RESET_FREQ      8       /* Reset controller every 8th retry */
  60 #define RECAL_FREQ      4       /* Recalibrate every 4th retry */
  61 #define MAX_HD          2
  62 
  63 #define STAT_OK         (READY_STAT|SEEK_STAT)
  64 #define OK_STATUS(s)    (((s)&(STAT_OK|(BUSY_STAT|WRERR_STAT|ERR_STAT)))==STAT_OK)
  65 
  66 static void recal_intr(void);
  67 static void bad_rw_intr(void);
  68 
  69 static char recalibrate[MAX_HD] = { 0, };
  70 static char special_op[MAX_HD] = { 0, };
  71 static int access_count[MAX_HD] = {0, };
  72 static char busy[MAX_HD] = {0, };
  73 static struct wait_queue * busy_wait = NULL;
  74 
  75 static int reset = 0;
  76 static int hd_error = 0;
  77 
  78 /*
  79  *  This struct defines the HD's and their types.
  80  */
  81 struct hd_i_struct {
  82         unsigned int head,sect,cyl,wpcom,lzone,ctl;
  83         };
  84 static struct hd_driveid *hd_ident_info[MAX_HD] = {0, };
  85         
  86 #ifdef HD_TYPE
  87 static struct hd_i_struct hd_info[] = { HD_TYPE };
  88 struct hd_i_struct bios_info[] = { HD_TYPE };
  89 static int NR_HD = ((sizeof (hd_info))/(sizeof (struct hd_i_struct)));
  90 #else
  91 static struct hd_i_struct hd_info[] = { {0,0,0,0,0,0},{0,0,0,0,0,0} };
  92 struct hd_i_struct bios_info[] = { {0,0,0,0,0,0},{0,0,0,0,0,0} };
  93 static int NR_HD = 0;
  94 #endif
  95 
  96 static struct hd_struct hd[MAX_HD<<6]={{0,0},};
  97 static int hd_sizes[MAX_HD<<6] = {0, };
  98 static int hd_blocksizes[MAX_HD<<6] = {0, };
  99 
 100 #if (HD_DELAY > 0)
 101 unsigned long last_req;
 102 
 103 unsigned long read_timer(void)
     /*  */
 104 {
 105         unsigned long t, flags;
 106         int i;
 107 
 108         save_flags(flags);
 109         cli();
 110         t = jiffies * 11932;
 111         outb_p(0, 0x43);
 112         i = inb_p(0x40);
 113         i |= inb(0x40) << 8;
 114         restore_flags(flags);
 115         return(t - i);
 116 }
 117 #endif
 118 
 119 void hd_setup(char *str, int *ints)
     /*  */
 120 {
 121         int hdind = 0;
 122 
 123         if (ints[0] != 3)
 124                 return;
 125         if (bios_info[0].head != 0)
 126                 hdind=1;
 127         bios_info[hdind].head  = hd_info[hdind].head = ints[2];
 128         bios_info[hdind].sect  = hd_info[hdind].sect = ints[3];
 129         bios_info[hdind].cyl   = hd_info[hdind].cyl = ints[1];
 130         bios_info[hdind].wpcom = hd_info[hdind].wpcom = 0;
 131         bios_info[hdind].lzone = hd_info[hdind].lzone = ints[1];
 132         bios_info[hdind].ctl   = hd_info[hdind].ctl = (ints[2] > 8 ? 8 : 0);
 133         NR_HD = hdind+1;
 134 }
 135 
 136 static void dump_status (char *msg, unsigned int stat)
     /*  */
 137 {
 138         unsigned long flags;
 139         char devc;
 140 
 141         devc = CURRENT ? 'a' + DEVICE_NR(CURRENT->dev) : '?';
 142         save_flags (flags);
 143         sti();
 144         printk("hd%c: %s: status=0x%02x { ", devc, msg, stat & 0xff);
 145         if (stat & BUSY_STAT)   printk("Busy ");
 146         if (stat & READY_STAT)  printk("DriveReady ");
 147         if (stat & WRERR_STAT)  printk("WriteFault ");
 148         if (stat & SEEK_STAT)   printk("SeekComplete ");
 149         if (stat & DRQ_STAT)    printk("DataRequest ");
 150         if (stat & ECC_STAT)    printk("CorrectedError ");
 151         if (stat & INDEX_STAT)  printk("Index ");
 152         if (stat & ERR_STAT)    printk("Error ");
 153         printk("}\n");
 154         if ((stat & ERR_STAT) == 0) {
 155                 hd_error = 0;
 156         } else {
 157                 hd_error = inb(HD_ERROR);
 158                 printk("hd%c: %s: error=0x%02x { ", devc, msg, hd_error & 0xff);
 159                 if (hd_error & BBD_ERR)         printk("BadSector ");
 160                 if (hd_error & ECC_ERR)         printk("UncorrectableError ");
 161                 if (hd_error & ID_ERR)          printk("SectorIdNotFound ");
 162                 if (hd_error & ABRT_ERR)        printk("DriveStatusError ");
 163                 if (hd_error & TRK0_ERR)        printk("TrackZeroNotFound ");
 164                 if (hd_error & MARK_ERR)        printk("AddrMarkNotFound ");
 165                 printk("}");
 166                 if (hd_error & (BBD_ERR|ECC_ERR|ID_ERR|MARK_ERR)) {
 167                         printk(", CHS=%d/%d/%d", (inb(HD_HCYL)<<8) + inb(HD_LCYL),
 168                                 inb(HD_CURRENT) & 0xf, inb(HD_SECTOR));
 169                         if (CURRENT)
 170                                 printk(", sector=%ld", CURRENT->sector);
 171                 }
 172                 printk("\n");
 173         }
 174         restore_flags (flags);
 175 }
 176 
 177 void check_status(void)
     /*  */
 178 {
 179         int i = inb_p(HD_STATUS);
 180 
 181         if (!OK_STATUS(i)) {
 182                 dump_status("check_status", i);
 183                 bad_rw_intr();
 184         }
 185 }
 186 
 187 static int controller_busy(void)
     /*  */
 188 {
 189         int retries = 100000;
 190         unsigned char status;
 191 
 192         do {
 193                 status = inb_p(HD_STATUS);
 194         } while ((status & BUSY_STAT) && --retries);
 195         return status;
 196 }
 197 
 198 static int status_ok(void)
     /*  */
 199 {
 200         unsigned char status = inb_p(HD_STATUS);
 201 
 202         if (status & BUSY_STAT)
 203                 return 1;       /* Ancient, but does it make sense??? */
 204         if (status & WRERR_STAT)
 205                 return 0;
 206         if (!(status & READY_STAT))
 207                 return 0;
 208         if (!(status & SEEK_STAT))
 209                 return 0;
 210         return 1;
 211 }
 212 
 213 static int controller_ready(unsigned int drive, unsigned int head)
     /*  */
 214 {
 215         int retry = 100;
 216 
 217         do {
 218                 if (controller_busy() & BUSY_STAT)
 219                         return 0;
 220                 outb_p(0xA0 | (drive<<4) | head, HD_CURRENT);
 221                 if (status_ok())
 222                         return 1;
 223         } while (--retry);
 224         return 0;
 225 }
 226 
 227 static void hd_out(unsigned int drive,unsigned int nsect,unsigned int sect,
     /*  */
 228                 unsigned int head,unsigned int cyl,unsigned int cmd,
 229                 void (*intr_addr)(void))
 230 {
 231         unsigned short port;
 232 
 233 #if (HD_DELAY > 0)
 234         while (read_timer() - last_req < HD_DELAY)
 235                 /* nothing */;
 236 #endif
 237         if (reset)
 238                 return;
 239         if (!controller_ready(drive, head)) {
 240                 reset = 1;
 241                 return;
 242         }
 243         SET_INTR(intr_addr);
 244         outb_p(hd_info[drive].ctl,HD_CMD);
 245         port=HD_DATA;
 246         outb_p(hd_info[drive].wpcom>>2,++port);
 247         outb_p(nsect,++port);
 248         outb_p(sect,++port);
 249         outb_p(cyl,++port);
 250         outb_p(cyl>>8,++port);
 251         outb_p(0xA0|(drive<<4)|head,++port);
 252         outb_p(cmd,++port);
 253 }
 254 
 255 static void hd_request (void);
 256 static unsigned int identified  [MAX_HD] = {0,}; /* 1 = drive ID already displayed   */
 257 static unsigned int unmask_intr [MAX_HD] = {0,}; /* 1 = unmask IRQs during I/O       */
 258 static unsigned int max_mult    [MAX_HD] = {0,}; /* max sectors for MultMode         */
 259 static unsigned int mult_req    [MAX_HD] = {0,}; /* requested MultMode count         */
 260 static unsigned int mult_count  [MAX_HD] = {0,}; /* currently enabled MultMode count */
 261 static struct request WCURRENT;
 262 
 263 static void fixstring (unsigned char *s, int bytecount)
     /*  */
 264 {
 265         unsigned char *p, *end = &s[bytecount &= ~1];   /* bytecount must be even */
 266 
 267         /* convert from big-endian to little-endian */
 268         for (p = end ; p != s;) {
 269                 unsigned short *pp = (unsigned short *) (p -= 2);
 270                 *pp = (*pp >> 8) | (*pp << 8);
 271         }
 272 
 273         /* strip leading blanks */
 274         while (s != end && *s == ' ')
 275                 ++s;
 276 
 277         /* compress internal blanks and strip trailing blanks */
 278         while (s != end && *s) {
 279                 if (*s++ != ' ' || (s != end && *s && *s != ' '))
 280                         *p++ = *(s-1);
 281         }
 282 
 283         /* wipe out trailing garbage */
 284         while (p != end)
 285                 *p++ = '\0';
 286 }
 287 
 288 static void identify_intr(void)
     /*  */
 289 {
 290         unsigned int dev = DEVICE_NR(CURRENT->dev);
 291         unsigned short stat = inb_p(HD_STATUS);
 292         struct hd_driveid *id = hd_ident_info[dev];
 293 
 294         if (unmask_intr[dev])
 295                 sti();
 296         if (stat & (BUSY_STAT|ERR_STAT)) {
 297                 printk ("  hd%c: non-IDE device, %dMB, CHS=%d/%d/%d\n", dev+'a',
 298                         hd_info[dev].cyl*hd_info[dev].head*hd_info[dev].sect / 2048,
 299                         hd_info[dev].cyl, hd_info[dev].head, hd_info[dev].sect);
 300                 if (id != NULL) {
 301                         hd_ident_info[dev] = NULL;
 302                         kfree_s (id, 512);
 303                 }
 304         } else {
 305                 insw(HD_DATA, id, 256); /* get ID info */
 306                 max_mult[dev] = id->max_multsect;
 307                 if ((id->field_valid&1) && id->cur_cyls && id->cur_heads && (id->cur_heads <= 16) && id->cur_sectors) {
 308                         /*
 309                          * Extract the physical drive geometry for our use.
 310                          * Note that we purposely do *not* update the bios_info.
 311                          * This way, programs that use it (like fdisk) will 
 312                          * still have the same logical view as the BIOS does,
 313                          * which keeps the partition table from being screwed.
 314                          */
 315                         hd_info[dev].cyl  = id->cur_cyls;
 316                         hd_info[dev].head = id->cur_heads;
 317                         hd_info[dev].sect = id->cur_sectors; 
 318                 }
 319                 fixstring (id->serial_no, sizeof(id->serial_no));
 320                 fixstring (id->fw_rev, sizeof(id->fw_rev));
 321                 fixstring (id->model, sizeof(id->model));
 322                 printk ("  hd%c: %.40s, %dMB w/%dKB Cache, CHS=%d/%d/%d, MaxMult=%d\n",
 323                         dev+'a', id->model, id->cyls*id->heads*id->sectors/2048,
 324                         id->buf_size/2, bios_info[dev].cyl, bios_info[dev].head,
 325                         bios_info[dev].sect, id->max_multsect);
 326                 /*
 327                  * Early model Quantum drives go weird at this point,
 328                  *   but doing a recalibrate seems to "fix" them.
 329                  * (Doing a full reset confuses some other model Quantums)
 330                  */
 331                 if (!strncmp(id->model, "QUANTUM", 7))
 332                         special_op[dev] = recalibrate[dev] = 1;
 333         }
 334 #if (HD_DELAY > 0)
 335         last_req = read_timer();
 336 #endif
 337         hd_request();
 338         return;
 339 }
 340 
 341 static void set_multmode_intr(void)
     /*  */
 342 {
 343         unsigned int dev = DEVICE_NR(CURRENT->dev), stat = inb_p(HD_STATUS);
 344 
 345         if (unmask_intr[dev])
 346                 sti();
 347         if (stat & (BUSY_STAT|ERR_STAT)) {
 348                 mult_req[dev] = mult_count[dev] = 0;
 349                 dump_status("set multmode failed", stat);
 350         } else {
 351                 if ((mult_count[dev] = mult_req[dev]))
 352                         printk ("  hd%c: enabled %d-sector multiple mode\n",
 353                                 dev+'a', mult_count[dev]);
 354                 else
 355                         printk ("  hd%c: disabled multiple mode\n", dev+'a');
 356         }
 357 #if (HD_DELAY > 0)
 358         last_req = read_timer();
 359 #endif
 360         hd_request();
 361         return;
 362 }
 363 
 364 static int drive_busy(void)
     /*  */
 365 {
 366         unsigned int i;
 367         unsigned char c;
 368 
 369         for (i = 0; i < 500000 ; i++) {
 370                 c = inb_p(HD_STATUS);
 371                 if ((c & (BUSY_STAT | READY_STAT | SEEK_STAT)) == STAT_OK)
 372                         return 0;
 373         }
 374         dump_status("reset timed out", c);
 375         return 1;
 376 }
 377 
 378 static void reset_controller(void)
     /*  */
 379 {
 380         int     i;
 381 
 382         outb_p(4,HD_CMD);
 383         for(i = 0; i < 1000; i++) nop();
 384         outb_p(hd_info[0].ctl & 0x0f,HD_CMD);
 385         for(i = 0; i < 1000; i++) nop();
 386         if (drive_busy())
 387                 printk("hd: controller still busy\n");
 388         else if ((hd_error = inb(HD_ERROR)) != 1)
 389                 printk("hd: controller reset failed: %02x\n",hd_error);
 390 }
 391 
 392 static void reset_hd(void)
     /*  */
 393 {
 394         static int i;
 395 
 396 repeat:
 397         if (reset) {
 398                 reset = 0;
 399                 i = -1;
 400                 reset_controller();
 401         } else {
 402                 check_status();
 403                 if (reset)
 404                         goto repeat;
 405         }
 406         if (++i < NR_HD) {
 407                 special_op[i] = recalibrate[i] = 1;
 408                 if (unmask_intr[i]) {
 409                         unmask_intr[i] = DEFAULT_UNMASK_INTR;
 410                         printk("hd%c: reset irq-unmasking to %d\n",i+'a',
 411                                 DEFAULT_UNMASK_INTR);
 412                 }
 413                 if (mult_req[i] || mult_count[i]) {
 414                         mult_count[i] = 0;
 415                         mult_req[i] = DEFAULT_MULT_COUNT;
 416                         printk("hd%c: reset multiple mode to %d\n",i+'a',
 417                                 DEFAULT_MULT_COUNT);
 418                 }
 419                 hd_out(i,hd_info[i].sect,hd_info[i].sect,hd_info[i].head-1,
 420                         hd_info[i].cyl,WIN_SPECIFY,&reset_hd);
 421                 if (reset)
 422                         goto repeat;
 423         } else
 424                 hd_request();
 425 }
 426 
 427 /*
 428  * Ok, don't know what to do with the unexpected interrupts: on some machines
 429  * doing a reset and a retry seems to result in an eternal loop. Right now I
 430  * ignore it, and just set the timeout.
 431  *
 432  * On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
 433  * drive enters "idle", "standby", or "sleep" mode, so if the status looks
 434  * "good", we just ignore the interrupt completely.
 435  */
 436 void unexpected_hd_interrupt(void)
     /*  */
 437 {
 438         unsigned int stat = inb_p(HD_STATUS);
 439 
 440         if (stat & (BUSY_STAT|DRQ_STAT|ECC_STAT|ERR_STAT)) {
 441                 dump_status ("unexpected interrupt", stat);
 442                 SET_TIMER;
 443         }
 444 }
 445 
 446 /*
 447  * bad_rw_intr() now tries to be a bit smarter and does things
 448  * according to the error returned by the controller.
 449  * -Mika Liljeberg (liljeber@cs.Helsinki.FI)
 450  */
 451 static void bad_rw_intr(void)
     /*  */
 452 {
 453         int dev;
 454 
 455         if (!CURRENT)
 456                 return;
 457         dev = DEVICE_NR(CURRENT->dev);
 458         if (++CURRENT->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) {
 459                 end_request(0);
 460                 special_op[dev] = recalibrate[dev] = 1;
 461         } else if (CURRENT->errors % RESET_FREQ == 0)
 462                 reset = 1;
 463         else if ((hd_error & TRK0_ERR) || CURRENT->errors % RECAL_FREQ == 0)
 464                 special_op[dev] = recalibrate[dev] = 1;
 465         /* Otherwise just retry */
 466 }
 467 
 468 static inline int wait_DRQ(void)
     /*  */
 469 {
 470         int retries = 100000, stat;
 471 
 472         while (--retries > 0)
 473                 if ((stat = inb_p(HD_STATUS)) & DRQ_STAT)
 474                         return 0;
 475         dump_status("wait_DRQ", stat);
 476         return -1;
 477 }
 478 
 479 static void read_intr(void)
     /*  */
 480 {
 481         unsigned int dev = DEVICE_NR(CURRENT->dev);
 482         int i, retries = 100000, msect = mult_count[dev], nsect;
 483 
 484         if (unmask_intr[dev])
 485                 sti();                  /* permit other IRQs during xfer */
 486         do {
 487                 i = (unsigned) inb_p(HD_STATUS);
 488                 if (i & BUSY_STAT)
 489                         continue;
 490                 if (!OK_STATUS(i))
 491                         break;
 492                 if (i & DRQ_STAT)
 493                         goto ok_to_read;
 494         } while (--retries > 0);
 495         dump_status("read_intr", i);
 496         bad_rw_intr();
 497         hd_request();
 498         return;
 499 ok_to_read:
 500         if (msect) {
 501                 if ((nsect = CURRENT->current_nr_sectors) > msect)
 502                         nsect = msect;
 503                 msect -= nsect;
 504         } else
 505                 nsect = 1;
 506         insw(HD_DATA,CURRENT->buffer,nsect<<8);
 507         CURRENT->sector += nsect;
 508         CURRENT->buffer += nsect<<9;
 509         CURRENT->errors = 0;
 510         i = (CURRENT->nr_sectors -= nsect);
 511 
 512 #ifdef DEBUG
 513         printk("hd%c: read: sectors(%ld-%ld), remaining=%ld, buffer=0x%08lx\n",
 514                 dev+'a', CURRENT->sector, CURRENT->sector+nsect,
 515                 CURRENT->nr_sectors, (unsigned long) CURRENT->buffer+(nsect<<9));
 516 #endif
 517         if ((CURRENT->current_nr_sectors -= nsect) <= 0)
 518                 end_request(1);
 519         if (i > 0) {
 520                 if (msect)
 521                         goto ok_to_read;
 522                 SET_INTR(&read_intr);
 523                 return;
 524         }
 525         (void) inb_p(HD_STATUS);
 526 #if (HD_DELAY > 0)
 527         last_req = read_timer();
 528 #endif
 529         if (CURRENT)
 530                 hd_request();
 531         return;
 532 }
 533 
 534 static inline void multwrite (unsigned int dev)
     /*  */
 535 {
 536         unsigned int mcount = mult_count[dev];
 537 
 538         while (mcount--) {
 539                 outsw(HD_DATA,WCURRENT.buffer,256);
 540                 if (!--WCURRENT.nr_sectors)
 541                         return;
 542                 WCURRENT.buffer += 512;
 543                 if (!--WCURRENT.current_nr_sectors) {
 544                         WCURRENT.bh = WCURRENT.bh->b_reqnext;
 545                         if (WCURRENT.bh == NULL)
 546                                 panic("buffer list corrupted\n");
 547                         WCURRENT.current_nr_sectors = WCURRENT.bh->b_size>>9;
 548                         WCURRENT.buffer             = WCURRENT.bh->b_data;
 549                 }
 550         }
 551 }
 552 
 553 static void multwrite_intr(void)
     /*  */
 554 {
 555         int i;
 556         unsigned int dev = DEVICE_NR(WCURRENT.dev);
 557 
 558         if (unmask_intr[dev])
 559                 sti();
 560         if (OK_STATUS(i=inb_p(HD_STATUS))) {
 561                 if (i & DRQ_STAT) {
 562                         if (WCURRENT.nr_sectors) {
 563                                 multwrite(dev);
 564                                 SET_INTR(&multwrite_intr);
 565                                 return;
 566                         }
 567                 } else {
 568                         if (!WCURRENT.nr_sectors) {     /* all done? */
 569                                 for (i = CURRENT->nr_sectors; i > 0;){
 570                                         i -= CURRENT->current_nr_sectors;
 571                                         end_request(1);
 572                                 }
 573 #if (HD_DELAY > 0)
 574                                 last_req = read_timer();
 575 #endif
 576                                 if (CURRENT)
 577                                         hd_request();
 578                                 return;
 579                         }
 580                 }
 581         }
 582         dump_status("multwrite_intr", i);
 583         bad_rw_intr();
 584         hd_request();
 585 }
 586 
 587 static void write_intr(void)
     /*  */
 588 {
 589         int i;
 590         int retries = 100000;
 591 
 592         if (unmask_intr[DEVICE_NR(WCURRENT.dev)])
 593                 sti();
 594         do {
 595                 i = (unsigned) inb_p(HD_STATUS);
 596                 if (i & BUSY_STAT)
 597                         continue;
 598                 if (!OK_STATUS(i))
 599                         break;
 600                 if ((CURRENT->nr_sectors <= 1) || (i & DRQ_STAT))
 601                         goto ok_to_write;
 602         } while (--retries > 0);
 603         dump_status("write_intr", i);
 604         bad_rw_intr();
 605         hd_request();
 606         return;
 607 ok_to_write:
 608         CURRENT->sector++;
 609         i = --CURRENT->nr_sectors;
 610         --CURRENT->current_nr_sectors;
 611         CURRENT->buffer += 512;
 612         if (!i || (CURRENT->bh && !SUBSECTOR(i)))
 613                 end_request(1);
 614         if (i > 0) {
 615                 SET_INTR(&write_intr);
 616                 outsw(HD_DATA,CURRENT->buffer,256);
 617                 sti();
 618         } else {
 619 #if (HD_DELAY > 0)
 620                 last_req = read_timer();
 621 #endif
 622                 hd_request();
 623         }
 624         return;
 625 }
 626 
 627 static void recal_intr(void)
     /*  */
 628 {
 629         check_status();
 630 #if (HD_DELAY > 0)
 631         last_req = read_timer();
 632 #endif
 633         hd_request();
 634 }
 635 
 636 /*
 637  * This is another of the error-routines I don't know what to do with. The
 638  * best idea seems to just set reset, and start all over again.
 639  */
 640 static void hd_times_out(void)
     /*  */
 641 {
 642         unsigned int dev;
 643 
 644         DEVICE_INTR = NULL;
 645         if (!CURRENT)
 646                 return;
 647         disable_irq(HD_IRQ);
 648         sti();
 649         reset = 1;
 650         dev = DEVICE_NR(CURRENT->dev);
 651         printk("hd%c: timeout\n", dev+'a');
 652         if (++CURRENT->errors >= MAX_ERRORS) {
 653 #ifdef DEBUG
 654                 printk("hd%c: too many errors\n", dev+'a');
 655 #endif
 656                 end_request(0);
 657         }
 658         cli();
 659         hd_request();
 660         enable_irq(HD_IRQ);
 661 }
 662 
 663 int do_special_op (unsigned int dev)
     /*  */
 664 {
 665         if (recalibrate[dev]) {
 666                 recalibrate[dev] = 0;
 667                 hd_out(dev,hd_info[dev].sect,0,0,0,WIN_RESTORE,&recal_intr);
 668                 return reset;
 669         }
 670         if (!identified[dev]) {
 671                 identified[dev]  = 1;
 672                 unmask_intr[dev] = DEFAULT_UNMASK_INTR;
 673                 mult_req[dev]    = DEFAULT_MULT_COUNT;
 674                 hd_out(dev,0,0,0,0,WIN_IDENTIFY,&identify_intr);
 675                 return reset;
 676         }
 677         if (mult_req[dev] != mult_count[dev]) {
 678                 hd_out(dev,mult_req[dev],0,0,0,WIN_SETMULT,&set_multmode_intr);
 679                 return reset;
 680         }
 681         if (hd_info[dev].head > 16) {
 682                 printk ("hd%c: cannot handle device with more than 16 heads - giving up\n", dev+'a');
 683                 end_request(0);
 684         }
 685         special_op[dev] = 0;
 686         return 1;
 687 }
 688 
 689 /*
 690  * The driver enables interrupts as much as possible.  In order to do this,
 691  * (a) the device-interrupt is disabled before entering hd_request(),
 692  * and (b) the timeout-interrupt is disabled before the sti().
 693  *
 694  * Interrupts are still masked (by default) whenever we are exchanging
 695  * data/cmds with a drive, because some drives seem to have very poor
 696  * tolerance for latency during I/O.  For devices which don't suffer from
 697  * that problem (most don't), the unmask_intr[] flag can be set to unmask
 698  * other interrupts during data/cmd transfers (by defining DEFAULT_UNMASK_INTR
 699  * to 1, or by using "hdparm -u1 /dev/hd?" from the shell).
 700  */
 701 static void hd_request(void)
     /*  */
 702 {
 703         unsigned int dev, block, nsect, sec, track, head, cyl;
 704 
 705         if (CURRENT && CURRENT->dev < 0) return;
 706         if (DEVICE_INTR)
 707                 return;
 708 repeat:
 709         timer_active &= ~(1<<HD_TIMER);
 710         sti();
 711         INIT_REQUEST;
 712         if (reset) {
 713                 cli();
 714                 reset_hd();
 715                 return;
 716         }
 717         dev = MINOR(CURRENT->dev);
 718         block = CURRENT->sector;
 719         nsect = CURRENT->nr_sectors;
 720         if (dev >= (NR_HD<<6) || block >= hd[dev].nr_sects || ((block+nsect) > hd[dev].nr_sects)) {
 721 #ifdef DEBUG
 722                 if (dev >= (NR_HD<<6))
 723                         printk("hd: bad minor number: device=0x%04x\n", CURRENT->dev);
 724                 else
 725                         printk("hd%c: bad access: block=%d, count=%d\n",
 726                                 (CURRENT->dev>>6)+'a', block, nsect);
 727 #endif
 728                 end_request(0);
 729                 goto repeat;
 730         }
 731         block += hd[dev].start_sect;
 732         dev >>= 6;
 733         if (special_op[dev]) {
 734                 if (do_special_op(dev))
 735                         goto repeat;
 736                 return;
 737         }
 738         sec   = block % hd_info[dev].sect + 1;
 739         track = block / hd_info[dev].sect;
 740         head  = track % hd_info[dev].head;
 741         cyl   = track / hd_info[dev].head;
 742 #ifdef DEBUG
 743         printk("hd%c: %sing: CHS=%d/%d/%d, sectors=%d, buffer=0x%08lx\n",
 744                 dev+'a', (CURRENT->cmd == READ)?"read":"writ",
 745                 cyl, head, sec, nsect, (unsigned long) CURRENT->buffer);
 746 #endif
 747         if (!unmask_intr[dev])
 748                 cli();
 749         if (CURRENT->cmd == READ) {
 750                 unsigned int cmd = mult_count[dev] > 1 ? WIN_MULTREAD : WIN_READ;
 751                 hd_out(dev,nsect,sec,head,cyl,cmd,&read_intr);
 752                 if (reset)
 753                         goto repeat;
 754                 return;
 755         }
 756         if (CURRENT->cmd == WRITE) {
 757                 if (mult_count[dev])
 758                         hd_out(dev,nsect,sec,head,cyl,WIN_MULTWRITE,&multwrite_intr);
 759                 else
 760                         hd_out(dev,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
 761                 if (reset)
 762                         goto repeat;
 763                 if (wait_DRQ()) {
 764                         bad_rw_intr();
 765                         goto repeat;
 766                 }
 767                 if (mult_count[dev]) {
 768                         WCURRENT = *CURRENT;
 769                         multwrite(dev);
 770                 } else
 771                         outsw(HD_DATA,CURRENT->buffer,256);
 772                 return;
 773         }
 774         panic("unknown hd-command");
 775 }
 776 
 777 static void do_hd_request (void)
     /*  */
 778 {
 779         disable_irq(HD_IRQ);
 780         hd_request();
 781         enable_irq(HD_IRQ);
 782 }
 783 
 784 static int hd_ioctl(struct inode * inode, struct file * file,
     /*  */
 785         unsigned int cmd, unsigned long arg)
 786 {
 787         struct hd_geometry *loc = (struct hd_geometry *) arg;
 788         int dev, err;
 789         unsigned long flags;
 790 
 791         if ((!inode) || (!inode->i_rdev))
 792                 return -EINVAL;
 793         dev = DEVICE_NR(inode->i_rdev);
 794         if (dev >= NR_HD)
 795                 return -EINVAL;
 796         switch (cmd) {
 797                 case HDIO_GETGEO:
 798                         if (!loc)  return -EINVAL;
 799                         err = verify_area(VERIFY_WRITE, loc, sizeof(*loc));
 800                         if (err)
 801                                 return err;
 802                         put_fs_byte(bios_info[dev].head,
 803                                 (char *) &loc->heads);
 804                         put_fs_byte(bios_info[dev].sect,
 805                                 (char *) &loc->sectors);
 806                         put_fs_word(bios_info[dev].cyl,
 807                                 (short *) &loc->cylinders);
 808                         put_fs_long(hd[MINOR(inode->i_rdev)].start_sect,
 809                                 (long *) &loc->start);
 810                         return 0;
 811                 case BLKRASET:
 812                         if(!suser())  return -EACCES;
 813                         if(arg > 0xff) return -EINVAL;
 814                         read_ahead[MAJOR(inode->i_rdev)] = arg;
 815                         return 0;
 816                 case BLKRAGET:
 817                         if (!arg)  return -EINVAL;
 818                         err = verify_area(VERIFY_WRITE, (long *) arg, sizeof(long));
 819                         if (err)
 820                                 return err;
 821                         put_fs_long(read_ahead[MAJOR(inode->i_rdev)],(long *) arg);
 822                         return 0;
 823                 case BLKGETSIZE:   /* Return device size */
 824                         if (!arg)  return -EINVAL;
 825                         err = verify_area(VERIFY_WRITE, (long *) arg, sizeof(long));
 826                         if (err)
 827                                 return err;
 828                         put_fs_long(hd[MINOR(inode->i_rdev)].nr_sects, (long *) arg);
 829                         return 0;
 830                 case BLKFLSBUF:
 831                         if(!suser())  return -EACCES;
 832                         fsync_dev(inode->i_rdev);
 833                         invalidate_buffers(inode->i_rdev);
 834                         return 0;
 835 
 836                 case BLKRRPART: /* Re-read partition tables */
 837                         return revalidate_hddisk(inode->i_rdev, 1);
 838 
 839                 case HDIO_SETUNMASKINTR:        /* obsolete */
 840                         printk("hd: obsolete syscall: HDIO_SETUNMASKINTR\n");
 841                         if (!arg)  return -EINVAL;
 842                         err = verify_area(VERIFY_READ, (long *) arg, sizeof(long));
 843                         if (err)
 844                                 return err;
 845                         arg = get_fs_long((long *) arg);
 846                         /* drop into HDIO_SET_UNMASKINTR */
 847                 case HDIO_SET_UNMASKINTR:
 848                         if (!suser()) return -EACCES;
 849                         if ((arg > 1) || (MINOR(inode->i_rdev) & 0x3F))
 850                                 return -EINVAL;
 851                         unmask_intr[dev] = arg;
 852                         return 0;
 853 
 854                 case HDIO_GET_UNMASKINTR:
 855                         if (!arg)  return -EINVAL;
 856                         err = verify_area(VERIFY_WRITE, (long *) arg, sizeof(long));
 857                         if (err)
 858                                 return err;
 859                         put_fs_long(unmask_intr[dev], (long *) arg);
 860                         return 0;
 861 
 862                 case HDIO_GET_MULTCOUNT:
 863                         if (!arg)  return -EINVAL;
 864                         err = verify_area(VERIFY_WRITE, (long *) arg, sizeof(long));
 865                         if (err)
 866                                 return err;
 867                         put_fs_long(mult_count[dev], (long *) arg);
 868                         return 0;
 869 
 870                 case HDIO_SETMULTCOUNT:         /* obsolete */
 871                         printk("hd: obsolete syscall: HDIO_SETMULTCOUNT\n");
 872                         if (!arg)  return -EINVAL;
 873                         err = verify_area(VERIFY_READ, (long *) arg, sizeof(long));
 874                         if (err)
 875                                 return err;
 876                         arg = get_fs_long((long *) arg);
 877                         /* drop into HDIO_SET_MULTCOUNT */
 878                 case HDIO_SET_MULTCOUNT:
 879                         if (!suser()) return -EACCES;
 880                         if (MINOR(inode->i_rdev) & 0x3F) return -EINVAL;
 881                         save_flags(flags);
 882                         cli();  /* a prior request might still be in progress */
 883                         if (arg > max_mult[dev])
 884                                 err = -EINVAL;  /* out of range for device */
 885                         else if (mult_req[dev] != mult_count[dev]) {
 886                                 special_op[dev] = 1;
 887                                 err = -EBUSY;   /* busy, try again */
 888                         } else {
 889                                 mult_req[dev] = arg;
 890                                 special_op[dev] = 1;
 891                                 err = 0;
 892                         }
 893                         restore_flags(flags);
 894                         return err;
 895 
 896                 case HDIO_GET_IDENTITY:
 897                         if (!arg)  return -EINVAL;
 898                         if (MINOR(inode->i_rdev) & 0x3F) return -EINVAL;
 899                         if (hd_ident_info[dev] == NULL)  return -ENOMSG;
 900                         err = verify_area(VERIFY_WRITE, (char *) arg, sizeof(struct hd_driveid));
 901                         if (err)
 902                                 return err;
 903                         memcpy_tofs((char *)arg, (char *) hd_ident_info[dev], sizeof(struct hd_driveid));
 904                         return 0;
 905 
 906                 RO_IOCTLS(inode->i_rdev,arg);
 907                 default:
 908                         return -EINVAL;
 909         }
 910 }
 911 
 912 static int hd_open(struct inode * inode, struct file * filp)
     /*  */
 913 {
 914         int target;
 915         target =  DEVICE_NR(inode->i_rdev);
 916 
 917         while (busy[target])
 918                 sleep_on(&busy_wait);
 919         access_count[target]++;
 920         return 0;
 921 }
 922 
 923 /*
 924  * Releasing a block device means we sync() it, so that it can safely
 925  * be forgotten about...
 926  */
 927 static void hd_release(struct inode * inode, struct file * file)
     /*  */
 928 {
 929         int target;
 930         sync_dev(inode->i_rdev);
 931 
 932         target =  DEVICE_NR(inode->i_rdev);
 933         access_count[target]--;
 934 
 935 }
 936 
 937 static void hd_geninit(void);
 938 
 939 static struct gendisk hd_gendisk = {
 940         MAJOR_NR,       /* Major number */      
 941         "hd",           /* Major name */
 942         6,              /* Bits to shift to get real from partition */
 943         1 << 6,         /* Number of partitions per real */
 944         MAX_HD,         /* maximum number of real */
 945         hd_geninit,     /* init function */
 946         hd,             /* hd struct */
 947         hd_sizes,       /* block sizes */
 948         0,              /* number */
 949         (void *) bios_info,     /* internal */
 950         NULL            /* next */
 951 };
 952         
 953 static void hd_interrupt(int unused)
     /*  */
 954 {
 955         void (*handler)(void) = DEVICE_INTR;
 956 
 957         DEVICE_INTR = NULL;
 958         timer_active &= ~(1<<HD_TIMER);
 959         if (!handler)
 960                 handler = unexpected_hd_interrupt;
 961         handler();
 962         sti();
 963 }
 964 
 965 /*
 966  * This is the harddisk IRQ description. The SA_INTERRUPT in sa_flags
 967  * means we run the IRQ-handler with interrupts disabled: this is bad for
 968  * interrupt latency, but anything else has led to problems on some
 969  * machines...
 970  *
 971  * We enable interrupts in some of the routines after making sure it's
 972  * safe.
 973  */
 974 static void hd_geninit(void)
     /*  */
 975 {
 976         int drive, i;
 977         extern struct drive_info drive_info;
 978         unsigned char *BIOS = (unsigned char *) &drive_info;
 979         int cmos_disks;
 980 
 981         if (!NR_HD) {      
 982                 for (drive=0 ; drive<2 ; drive++) {
 983                         bios_info[drive].cyl   = hd_info[drive].cyl = *(unsigned short *) BIOS;
 984                         bios_info[drive].head  = hd_info[drive].head = *(2+BIOS);
 985                         bios_info[drive].wpcom = hd_info[drive].wpcom = *(unsigned short *) (5+BIOS);
 986                         bios_info[drive].ctl   = hd_info[drive].ctl = *(8+BIOS);
 987                         bios_info[drive].lzone = hd_info[drive].lzone = *(unsigned short *) (12+BIOS);
 988                         bios_info[drive].sect  = hd_info[drive].sect = *(14+BIOS);
 989 #ifdef does_not_work_for_everybody_with_scsi_but_helps_ibm_vp
 990                         if (hd_info[drive].cyl && NR_HD == drive)
 991                                 NR_HD++;
 992 #endif
 993                         BIOS += 16;
 994                 }
 995 
 996         /*
 997                 We query CMOS about hard disks : it could be that 
 998                 we have a SCSI/ESDI/etc controller that is BIOS
 999                 compatible with ST-506, and thus showing up in our
1000                 BIOS table, but not register compatible, and therefore
1001                 not present in CMOS.
1002 
1003                 Furthermore, we will assume that our ST-506 drives
1004                 <if any> are the primary drives in the system, and 
1005                 the ones reflected as drive 1 or 2.
1006 
1007                 The first drive is stored in the high nibble of CMOS
1008                 byte 0x12, the second in the low nibble.  This will be
1009                 either a 4 bit drive type or 0xf indicating use byte 0x19 
1010                 for an 8 bit type, drive 1, 0x1a for drive 2 in CMOS.
1011 
1012                 Needless to say, a non-zero value means we have 
1013                 an AT controller hard disk for that drive.
1014 
1015                 
1016         */
1017 
1018                 if ((cmos_disks = CMOS_READ(0x12)) & 0xf0)
1019                         if (cmos_disks & 0x0f)
1020                                 NR_HD = 2;
1021                         else
1022                                 NR_HD = 1;
1023         }
1024         i = NR_HD;
1025         while (i-- > 0) {
1026                 /*
1027                  * The newer E-IDE BIOSs handle drives larger than 1024
1028                  * cylinders by increasing the number of logical heads
1029                  * to keep the number of logical cylinders below the
1030                  * sacred INT13 limit of 1024 (10 bits).  If that is
1031                  * what's happening here, we'll find out and correct
1032                  * it later when "identifying" the drive.
1033                  */
1034                 hd[i<<6].nr_sects = bios_info[i].head *
1035                                 bios_info[i].sect * bios_info[i].cyl;
1036                 hd_ident_info[i] = (struct hd_driveid *) kmalloc(512,GFP_KERNEL);
1037                 special_op[i] = 1;
1038         }
1039         if (NR_HD) {
1040                 if (request_irq(HD_IRQ, hd_interrupt, SA_INTERRUPT, "hd")) {
1041                         printk("hd: unable to get IRQ%d for the harddisk driver\n",HD_IRQ);
1042                         NR_HD = 0;
1043                 }
1044         }
1045         hd_gendisk.nr_real = NR_HD;
1046 
1047         for(i=0;i<(MAX_HD << 6);i++) hd_blocksizes[i] = 1024;
1048         blksize_size[MAJOR_NR] = hd_blocksizes;
1049 }
1050 
1051 static struct file_operations hd_fops = {
1052         NULL,                   /* lseek - default */
1053         block_read,             /* read - general block-dev read */
1054         block_write,            /* write - general block-dev write */
1055         NULL,                   /* readdir - bad */
1056         NULL,                   /* select */
1057         hd_ioctl,               /* ioctl */
1058         NULL,                   /* mmap */
1059         hd_open,                /* open */
1060         hd_release,             /* release */
1061         block_fsync             /* fsync */
1062 };
1063 
1064 unsigned long hd_init(unsigned long mem_start, unsigned long mem_end)
     /*  */
1065 {
1066         if (register_blkdev(MAJOR_NR,"hd",&hd_fops)) {
1067                 printk("hd: unable to get major %d for harddisk\n",MAJOR_NR);
1068                 return mem_start;
1069         }
1070         blk_dev[MAJOR_NR].request_fn = DEVICE_REQUEST;
1071         read_ahead[MAJOR_NR] = 8;               /* 8 sector (4kB) read-ahead */
1072         hd_gendisk.next = gendisk_head;
1073         gendisk_head = &hd_gendisk;
1074         timer_table[HD_TIMER].fn = hd_times_out;
1075         return mem_start;
1076 }
1077 
1078 #define DEVICE_BUSY busy[target]
1079 #define USAGE access_count[target]
1080 #define CAPACITY (bios_info[target].head*bios_info[target].sect*bios_info[target].cyl)
1081 /* We assume that the the bios parameters do not change, so the disk capacity
1082    will not change */
1083 #undef MAYBE_REINIT
1084 #define GENDISK_STRUCT hd_gendisk
1085 
1086 /*
1087  * This routine is called to flush all partitions and partition tables
1088  * for a changed scsi disk, and then re-read the new partition table.
1089  * If we are revalidating a disk because of a media change, then we
1090  * enter with usage == 0.  If we are using an ioctl, we automatically have
1091  * usage == 1 (we need an open channel to use an ioctl :-), so this
1092  * is our limit.
1093  */
1094 static int revalidate_hddisk(int dev, int maxusage)
     /*  */
1095 {
1096         int target, major;
1097         struct gendisk * gdev;
1098         int max_p;
1099         int start;
1100         int i;
1101         long flags;
1102 
1103         target =  DEVICE_NR(dev);
1104         gdev = &GENDISK_STRUCT;
1105 
1106         save_flags(flags);
1107         cli();
1108         if (DEVICE_BUSY || USAGE > maxusage) {
1109                 restore_flags(flags);
1110                 return -EBUSY;
1111         };
1112         DEVICE_BUSY = 1;
1113         restore_flags(flags);
1114 
1115         max_p = gdev->max_p;
1116         start = target << gdev->minor_shift;
1117         major = MAJOR_NR << 8;
1118 
1119         for (i=max_p - 1; i >=0 ; i--) {
1120                 sync_dev(major | start | i);
1121                 invalidate_inodes(major | start | i);
1122                 invalidate_buffers(major | start | i);
1123                 gdev->part[start+i].start_sect = 0;
1124                 gdev->part[start+i].nr_sects = 0;
1125         };
1126 
1127 #ifdef MAYBE_REINIT
1128         MAYBE_REINIT;
1129 #endif
1130 
1131         gdev->part[start].nr_sects = CAPACITY;
1132         resetup_one_dev(gdev, target);
1133 
1134         DEVICE_BUSY = 0;
1135         wake_up(&busy_wait);
1136         return 0;
1137 }
1138
/* */
root/drivers/block/hd.c

DEFINITIONS
