1 /*
2 * linux/drivers/ide/legacy/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 Mark Lord.
20 *
21 * Removed 99% of above. Use Mark's ide driver for those options.
22 * This is now a lightweight ST-506 driver. (Paul Gortmaker)
23 *
24 * Modified 1995 Russell King for ARM processor.
25 *
26 * Bugfix: max_sectors must be <= 255 or the wheels tend to come
27 * off in a hurry once you queue things up - Paul G. 02/2001
28 */
29
30 /* Uncomment the following if you want verbose error reports. */
31 /* #define VERBOSE_ERRORS */
32
33 #include <linux/errno.h>
34 #include <linux/signal.h>
35 #include <linux/sched.h>
36 #include <linux/timer.h>
37 #include <linux/fs.h>
38 #include <linux/devfs_fs_kernel.h>
39 #include <linux/kernel.h>
40 #include <linux/hdreg.h>
41 #include <linux/genhd.h>
42 #include <linux/slab.h>
43 #include <linux/string.h>
44 #include <linux/ioport.h>
45 #include <linux/mc146818rtc.h> /* CMOS defines */
46 #include <linux/init.h>
47 #include <linux/blkpg.h>
48
49 #define REALLY_SLOW_IO
50 #include <asm/system.h>
51 #include <asm/io.h>
52 #include <asm/uaccess.h>
53
54 #define MAJOR_NR HD_MAJOR
55 #include <linux/blk.h>
56
57 #ifdef __arm__
58 #undef HD_IRQ
59 #endif
60 #include <asm/irq.h>
61 #ifdef __arm__
62 #define HD_IRQ IRQ_HARDDISK
63 #endif
64
65 static int revalidate_hddisk(kdev_t, int);
66
67 #define HD_DELAY 0
68
69 #define MAX_ERRORS 16 /* Max read/write errors/sector */
70 #define RESET_FREQ 8 /* Reset controller every 8th retry */
71 #define RECAL_FREQ 4 /* Recalibrate every 4th retry */
72 #define MAX_HD 2
73
74 #define STAT_OK (READY_STAT|SEEK_STAT)
75 #define OK_STATUS(s) (((s)&(STAT_OK|(BUSY_STAT|WRERR_STAT|ERR_STAT)))==STAT_OK)
76
77 static void recal_intr(void);
78 static void bad_rw_intr(void);
79
80 static char recalibrate[MAX_HD];
81 static char special_op[MAX_HD];
82 static int access_count[MAX_HD];
83 static char busy[MAX_HD];
84 static DECLARE_WAIT_QUEUE_HEAD(busy_wait);
85
86 static int reset;
87 static int hd_error;
88
89 #define SUBSECTOR(block) (CURRENT->current_nr_sectors > 0)
90
91 /*
92 * This struct defines the HD's and their types.
93 */
94 struct hd_i_struct {
95 unsigned int head,sect,cyl,wpcom,lzone,ctl;
96 };
97
98 #ifdef HD_TYPE
99 static struct hd_i_struct hd_info[] = { HD_TYPE };
100 static int NR_HD = ((sizeof (hd_info))/(sizeof (struct hd_i_struct)));
101 #else
102 static struct hd_i_struct hd_info[MAX_HD];
103 static int NR_HD;
104 #endif
105
106 static struct hd_struct hd[MAX_HD<<6];
107 static int hd_sizes[MAX_HD<<6];
108 static int hd_blocksizes[MAX_HD<<6];
109 static int hd_hardsectsizes[MAX_HD<<6];
110 static int hd_maxsect[MAX_HD<<6];
111
112 static struct timer_list device_timer;
113
114 #define SET_TIMER \
115 do { \
116 mod_timer(&device_timer, jiffies + TIMEOUT_VALUE); \
117 } while (0)
118
119 #define CLEAR_TIMER del_timer(&device_timer);
120
121 #undef SET_INTR
122
123 #define SET_INTR(x) \
124 if ((DEVICE_INTR = (x)) != NULL) \
125 SET_TIMER; \
126 else \
127 CLEAR_TIMER;
128
129
130 #if (HD_DELAY > 0)
131 unsigned long last_req;
132
read_timer(void)133 unsigned long read_timer(void)
134 {
135 unsigned long t, flags;
136 int i;
137
138 spin_lock_irqsave(&io_request_lock, flags);
139 t = jiffies * 11932;
140 outb_p(0, 0x43);
141 i = inb_p(0x40);
142 i |= inb(0x40) << 8;
143 spin_unlock_irqrestore(&io_request_lock, flags);
144 return(t - i);
145 }
146 #endif
147
hd_setup(char * str,int * ints)148 void __init hd_setup(char *str, int *ints)
149 {
150 int hdind = 0;
151
152 if (ints[0] != 3)
153 return;
154 if (hd_info[0].head != 0)
155 hdind=1;
156 hd_info[hdind].head = ints[2];
157 hd_info[hdind].sect = ints[3];
158 hd_info[hdind].cyl = ints[1];
159 hd_info[hdind].wpcom = 0;
160 hd_info[hdind].lzone = ints[1];
161 hd_info[hdind].ctl = (ints[2] > 8 ? 8 : 0);
162 NR_HD = hdind+1;
163 }
164
dump_status(const char * msg,unsigned int stat)165 static void dump_status (const char *msg, unsigned int stat)
166 {
167 unsigned long flags;
168 char devc;
169
170 devc = !QUEUE_EMPTY ? 'a' + DEVICE_NR(CURRENT->rq_dev) : '?';
171 save_flags (flags);
172 sti();
173 #ifdef VERBOSE_ERRORS
174 printk("hd%c: %s: status=0x%02x { ", devc, msg, stat & 0xff);
175 if (stat & BUSY_STAT) printk("Busy ");
176 if (stat & READY_STAT) printk("DriveReady ");
177 if (stat & WRERR_STAT) printk("WriteFault ");
178 if (stat & SEEK_STAT) printk("SeekComplete ");
179 if (stat & DRQ_STAT) printk("DataRequest ");
180 if (stat & ECC_STAT) printk("CorrectedError ");
181 if (stat & INDEX_STAT) printk("Index ");
182 if (stat & ERR_STAT) printk("Error ");
183 printk("}\n");
184 if ((stat & ERR_STAT) == 0) {
185 hd_error = 0;
186 } else {
187 hd_error = inb(HD_ERROR);
188 printk("hd%c: %s: error=0x%02x { ", devc, msg, hd_error & 0xff);
189 if (hd_error & BBD_ERR) printk("BadSector ");
190 if (hd_error & ECC_ERR) printk("UncorrectableError ");
191 if (hd_error & ID_ERR) printk("SectorIdNotFound ");
192 if (hd_error & ABRT_ERR) printk("DriveStatusError ");
193 if (hd_error & TRK0_ERR) printk("TrackZeroNotFound ");
194 if (hd_error & MARK_ERR) printk("AddrMarkNotFound ");
195 printk("}");
196 if (hd_error & (BBD_ERR|ECC_ERR|ID_ERR|MARK_ERR)) {
197 printk(", CHS=%d/%d/%d",
198 (inb(HD_HCYL)<<8) + inb(HD_LCYL),
199 inb(HD_CURRENT) & 0xf, inb(HD_SECTOR));
200 if (!QUEUE_EMPTY)
201 printk(", sector=%ld", CURRENT->sector);
202 }
203 printk("\n");
204 }
205 #else
206 printk("hd%c: %s: status=0x%02x.\n", devc, msg, stat & 0xff);
207 if ((stat & ERR_STAT) == 0) {
208 hd_error = 0;
209 } else {
210 hd_error = inb(HD_ERROR);
211 printk("hd%c: %s: error=0x%02x.\n", devc, msg, hd_error & 0xff);
212 }
213 #endif /* verbose errors */
214 restore_flags (flags);
215 }
216
check_status(void)217 void check_status(void)
218 {
219 int i = inb_p(HD_STATUS);
220
221 if (!OK_STATUS(i)) {
222 dump_status("check_status", i);
223 bad_rw_intr();
224 }
225 }
226
controller_busy(void)227 static int controller_busy(void)
228 {
229 int retries = 100000;
230 unsigned char status;
231
232 do {
233 status = inb_p(HD_STATUS);
234 } while ((status & BUSY_STAT) && --retries);
235 return status;
236 }
237
status_ok(void)238 static int status_ok(void)
239 {
240 unsigned char status = inb_p(HD_STATUS);
241
242 if (status & BUSY_STAT)
243 return 1; /* Ancient, but does it make sense??? */
244 if (status & WRERR_STAT)
245 return 0;
246 if (!(status & READY_STAT))
247 return 0;
248 if (!(status & SEEK_STAT))
249 return 0;
250 return 1;
251 }
252
controller_ready(unsigned int drive,unsigned int head)253 static int controller_ready(unsigned int drive, unsigned int head)
254 {
255 int retry = 100;
256
257 do {
258 if (controller_busy() & BUSY_STAT)
259 return 0;
260 outb_p(0xA0 | (drive<<4) | head, HD_CURRENT);
261 if (status_ok())
262 return 1;
263 } while (--retry);
264 return 0;
265 }
266
hd_out(unsigned int drive,unsigned int nsect,unsigned int sect,unsigned int head,unsigned int cyl,unsigned int cmd,void (* intr_addr)(void))267 static void hd_out(unsigned int drive,unsigned int nsect,unsigned int sect,
268 unsigned int head,unsigned int cyl,unsigned int cmd,
269 void (*intr_addr)(void))
270 {
271 unsigned short port;
272
273 #if (HD_DELAY > 0)
274 while (read_timer() - last_req < HD_DELAY)
275 /* nothing */;
276 #endif
277 if (reset)
278 return;
279 if (!controller_ready(drive, head)) {
280 reset = 1;
281 return;
282 }
283 SET_INTR(intr_addr);
284 outb_p(hd_info[drive].ctl,HD_CMD);
285 port=HD_DATA;
286 outb_p(hd_info[drive].wpcom>>2,++port);
287 outb_p(nsect,++port);
288 outb_p(sect,++port);
289 outb_p(cyl,++port);
290 outb_p(cyl>>8,++port);
291 outb_p(0xA0|(drive<<4)|head,++port);
292 outb_p(cmd,++port);
293 }
294
295 static void hd_request (void);
296
drive_busy(void)297 static int drive_busy(void)
298 {
299 unsigned int i;
300 unsigned char c;
301
302 for (i = 0; i < 500000 ; i++) {
303 c = inb_p(HD_STATUS);
304 if ((c & (BUSY_STAT | READY_STAT | SEEK_STAT)) == STAT_OK)
305 return 0;
306 }
307 dump_status("reset timed out", c);
308 return 1;
309 }
310
reset_controller(void)311 static void reset_controller(void)
312 {
313 int i;
314
315 outb_p(4,HD_CMD);
316 for(i = 0; i < 1000; i++) barrier();
317 outb_p(hd_info[0].ctl & 0x0f,HD_CMD);
318 for(i = 0; i < 1000; i++) barrier();
319 if (drive_busy())
320 printk("hd: controller still busy\n");
321 else if ((hd_error = inb(HD_ERROR)) != 1)
322 printk("hd: controller reset failed: %02x\n",hd_error);
323 }
324
reset_hd(void)325 static void reset_hd(void)
326 {
327 static int i;
328
329 repeat:
330 if (reset) {
331 reset = 0;
332 i = -1;
333 reset_controller();
334 } else {
335 check_status();
336 if (reset)
337 goto repeat;
338 }
339 if (++i < NR_HD) {
340 special_op[i] = recalibrate[i] = 1;
341 hd_out(i,hd_info[i].sect,hd_info[i].sect,hd_info[i].head-1,
342 hd_info[i].cyl,WIN_SPECIFY,&reset_hd);
343 if (reset)
344 goto repeat;
345 } else
346 hd_request();
347 }
348
do_reset_hd(void)349 void do_reset_hd(void)
350 {
351 DEVICE_INTR = NULL;
352 reset = 1;
353 reset_hd();
354 }
355
356 /*
357 * Ok, don't know what to do with the unexpected interrupts: on some machines
358 * doing a reset and a retry seems to result in an eternal loop. Right now I
359 * ignore it, and just set the timeout.
360 *
361 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
362 * drive enters "idle", "standby", or "sleep" mode, so if the status looks
363 * "good", we just ignore the interrupt completely.
364 */
unexpected_hd_interrupt(void)365 void unexpected_hd_interrupt(void)
366 {
367 unsigned int stat = inb_p(HD_STATUS);
368
369 if (stat & (BUSY_STAT|DRQ_STAT|ECC_STAT|ERR_STAT)) {
370 dump_status ("unexpected interrupt", stat);
371 SET_TIMER;
372 }
373 }
374
375 /*
376 * bad_rw_intr() now tries to be a bit smarter and does things
377 * according to the error returned by the controller.
378 * -Mika Liljeberg (liljeber@cs.Helsinki.FI)
379 */
bad_rw_intr(void)380 static void bad_rw_intr(void)
381 {
382 int dev;
383
384 if (QUEUE_EMPTY)
385 return;
386 dev = DEVICE_NR(CURRENT->rq_dev);
387 if (++CURRENT->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) {
388 end_request(0);
389 special_op[dev] = recalibrate[dev] = 1;
390 } else if (CURRENT->errors % RESET_FREQ == 0)
391 reset = 1;
392 else if ((hd_error & TRK0_ERR) || CURRENT->errors % RECAL_FREQ == 0)
393 special_op[dev] = recalibrate[dev] = 1;
394 /* Otherwise just retry */
395 }
396
wait_DRQ(void)397 static inline int wait_DRQ(void)
398 {
399 int retries = 100000, stat;
400
401 while (--retries > 0)
402 if ((stat = inb_p(HD_STATUS)) & DRQ_STAT)
403 return 0;
404 dump_status("wait_DRQ", stat);
405 return -1;
406 }
407
read_intr(void)408 static void read_intr(void)
409 {
410 int i, retries = 100000;
411
412 do {
413 i = (unsigned) inb_p(HD_STATUS);
414 if (i & BUSY_STAT)
415 continue;
416 if (!OK_STATUS(i))
417 break;
418 if (i & DRQ_STAT)
419 goto ok_to_read;
420 } while (--retries > 0);
421 dump_status("read_intr", i);
422 bad_rw_intr();
423 hd_request();
424 return;
425 ok_to_read:
426 insw(HD_DATA,CURRENT->buffer,256);
427 CURRENT->sector++;
428 CURRENT->buffer += 512;
429 CURRENT->errors = 0;
430 i = --CURRENT->nr_sectors;
431 --CURRENT->current_nr_sectors;
432 #ifdef DEBUG
433 printk("hd%c: read: sector %ld, remaining = %ld, buffer=0x%08lx\n",
434 dev+'a', CURRENT->sector, CURRENT->nr_sectors,
435 (unsigned long) CURRENT->buffer+512);
436 #endif
437 if (CURRENT->current_nr_sectors <= 0)
438 end_request(1);
439 if (i > 0) {
440 SET_INTR(&read_intr);
441 return;
442 }
443 (void) inb_p(HD_STATUS);
444 #if (HD_DELAY > 0)
445 last_req = read_timer();
446 #endif
447 if (!QUEUE_EMPTY)
448 hd_request();
449 return;
450 }
451
write_intr(void)452 static void write_intr(void)
453 {
454 int i;
455 int retries = 100000;
456
457 do {
458 i = (unsigned) inb_p(HD_STATUS);
459 if (i & BUSY_STAT)
460 continue;
461 if (!OK_STATUS(i))
462 break;
463 if ((CURRENT->nr_sectors <= 1) || (i & DRQ_STAT))
464 goto ok_to_write;
465 } while (--retries > 0);
466 dump_status("write_intr", i);
467 bad_rw_intr();
468 hd_request();
469 return;
470 ok_to_write:
471 CURRENT->sector++;
472 i = --CURRENT->nr_sectors;
473 --CURRENT->current_nr_sectors;
474 CURRENT->buffer += 512;
475 if (!i || (CURRENT->bh && !SUBSECTOR(i)))
476 end_request(1);
477 if (i > 0) {
478 SET_INTR(&write_intr);
479 outsw(HD_DATA,CURRENT->buffer,256);
480 sti();
481 } else {
482 #if (HD_DELAY > 0)
483 last_req = read_timer();
484 #endif
485 hd_request();
486 }
487 return;
488 }
489
recal_intr(void)490 static void recal_intr(void)
491 {
492 check_status();
493 #if (HD_DELAY > 0)
494 last_req = read_timer();
495 #endif
496 hd_request();
497 }
498
499 /*
500 * This is another of the error-routines I don't know what to do with. The
501 * best idea seems to just set reset, and start all over again.
502 */
hd_times_out(unsigned long dummy)503 static void hd_times_out(unsigned long dummy)
504 {
505 unsigned int dev;
506
507 DEVICE_INTR = NULL;
508 if (QUEUE_EMPTY)
509 return;
510 disable_irq(HD_IRQ);
511 sti();
512 reset = 1;
513 dev = DEVICE_NR(CURRENT->rq_dev);
514 printk("hd%c: timeout\n", dev+'a');
515 if (++CURRENT->errors >= MAX_ERRORS) {
516 #ifdef DEBUG
517 printk("hd%c: too many errors\n", dev+'a');
518 #endif
519 end_request(0);
520 }
521 cli();
522 hd_request();
523 enable_irq(HD_IRQ);
524 }
525
do_special_op(unsigned int dev)526 int do_special_op (unsigned int dev)
527 {
528 if (recalibrate[dev]) {
529 recalibrate[dev] = 0;
530 hd_out(dev,hd_info[dev].sect,0,0,0,WIN_RESTORE,&recal_intr);
531 return reset;
532 }
533 if (hd_info[dev].head > 16) {
534 printk ("hd%c: cannot handle device with more than 16 heads - giving up\n", dev+'a');
535 end_request(0);
536 }
537 special_op[dev] = 0;
538 return 1;
539 }
540
541 /*
542 * The driver enables interrupts as much as possible. In order to do this,
543 * (a) the device-interrupt is disabled before entering hd_request(),
544 * and (b) the timeout-interrupt is disabled before the sti().
545 *
546 * Interrupts are still masked (by default) whenever we are exchanging
547 * data/cmds with a drive, because some drives seem to have very poor
548 * tolerance for latency during I/O. The IDE driver has support to unmask
549 * interrupts for non-broken hardware, so use that driver if required.
550 */
hd_request(void)551 static void hd_request(void)
552 {
553 unsigned int dev, block, nsect, sec, track, head, cyl;
554
555 if (!QUEUE_EMPTY && CURRENT->rq_status == RQ_INACTIVE) return;
556 if (DEVICE_INTR)
557 return;
558 repeat:
559 del_timer(&device_timer);
560 sti();
561 INIT_REQUEST;
562 if (reset) {
563 cli();
564 reset_hd();
565 return;
566 }
567 dev = MINOR(CURRENT->rq_dev);
568 block = CURRENT->sector;
569 nsect = CURRENT->nr_sectors;
570 if (dev >= (NR_HD<<6) || block >= hd[dev].nr_sects || ((block+nsect) > hd[dev].nr_sects)) {
571 #ifdef DEBUG
572 if (dev >= (NR_HD<<6))
573 printk("hd: bad minor number: device=%s\n",
574 kdevname(CURRENT->rq_dev));
575 else
576 printk("hd%c: bad access: block=%d, count=%d\n",
577 (MINOR(CURRENT->rq_dev)>>6)+'a', block, nsect);
578 #endif
579 end_request(0);
580 goto repeat;
581 }
582 block += hd[dev].start_sect;
583 dev >>= 6;
584 if (special_op[dev]) {
585 if (do_special_op(dev))
586 goto repeat;
587 return;
588 }
589 sec = block % hd_info[dev].sect + 1;
590 track = block / hd_info[dev].sect;
591 head = track % hd_info[dev].head;
592 cyl = track / hd_info[dev].head;
593 #ifdef DEBUG
594 printk("hd%c: %sing: CHS=%d/%d/%d, sectors=%d, buffer=0x%08lx\n",
595 dev+'a', (CURRENT->cmd == READ)?"read":"writ",
596 cyl, head, sec, nsect, (unsigned long) CURRENT->buffer);
597 #endif
598 if (CURRENT->cmd == READ) {
599 hd_out(dev,nsect,sec,head,cyl,WIN_READ,&read_intr);
600 if (reset)
601 goto repeat;
602 return;
603 }
604 if (CURRENT->cmd == WRITE) {
605 hd_out(dev,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
606 if (reset)
607 goto repeat;
608 if (wait_DRQ()) {
609 bad_rw_intr();
610 goto repeat;
611 }
612 outsw(HD_DATA,CURRENT->buffer,256);
613 return;
614 }
615 panic("unknown hd-command");
616 }
617
do_hd_request(request_queue_t * q)618 static void do_hd_request (request_queue_t * q)
619 {
620 disable_irq(HD_IRQ);
621 hd_request();
622 enable_irq(HD_IRQ);
623 }
624
hd_ioctl(struct inode * inode,struct file * file,unsigned int cmd,unsigned long arg)625 static int hd_ioctl(struct inode * inode, struct file * file,
626 unsigned int cmd, unsigned long arg)
627 {
628 struct hd_geometry *loc = (struct hd_geometry *) arg;
629 int dev;
630
631 if ((!inode) || !(inode->i_rdev))
632 return -EINVAL;
633 dev = DEVICE_NR(inode->i_rdev);
634 if (dev >= NR_HD)
635 return -EINVAL;
636 switch (cmd) {
637 case HDIO_GETGEO:
638 {
639 struct hd_geometry g;
640 if (!loc) return -EINVAL;
641 g.heads = hd_info[dev].head;
642 g.sectors = hd_info[dev].sect;
643 g.cylinders = hd_info[dev].cyl;
644 g.start = hd[MINOR(inode->i_rdev)].start_sect;
645 return copy_to_user(loc, &g, sizeof g) ? -EFAULT : 0;
646 }
647
648 case BLKGETSIZE: /* Return device size */
649 return put_user(hd[MINOR(inode->i_rdev)].nr_sects,
650 (unsigned long *) arg);
651 case BLKGETSIZE64:
652 return put_user((u64)hd[MINOR(inode->i_rdev)].nr_sects << 9,
653 (u64 *) arg);
654
655 case BLKRRPART: /* Re-read partition tables */
656 if (!capable(CAP_SYS_ADMIN))
657 return -EACCES;
658 return revalidate_hddisk(inode->i_rdev, 1);
659
660 case BLKROSET:
661 case BLKROGET:
662 case BLKRASET:
663 case BLKRAGET:
664 case BLKFLSBUF:
665 case BLKPG:
666 return blk_ioctl(inode->i_rdev, cmd, arg);
667
668 default:
669 return -EINVAL;
670 }
671 }
672
hd_open(struct inode * inode,struct file * filp)673 static int hd_open(struct inode * inode, struct file * filp)
674 {
675 int target;
676 target = DEVICE_NR(inode->i_rdev);
677
678 if (target >= NR_HD)
679 return -ENODEV;
680 while (busy[target])
681 sleep_on(&busy_wait);
682 access_count[target]++;
683 return 0;
684 }
685
686 /*
687 * Releasing a block device means we sync() it, so that it can safely
688 * be forgotten about...
689 */
hd_release(struct inode * inode,struct file * file)690 static int hd_release(struct inode * inode, struct file * file)
691 {
692 int target = DEVICE_NR(inode->i_rdev);
693 access_count[target]--;
694 return 0;
695 }
696
697 static struct block_device_operations hd_fops = {
698 open: hd_open,
699 release: hd_release,
700 ioctl: hd_ioctl,
701 };
702
703 static struct gendisk hd_gendisk = {
704 major: MAJOR_NR,
705 major_name: "hd",
706 minor_shift: 6,
707 max_p: 1 << 6,
708 part: hd,
709 sizes: hd_sizes,
710 fops: &hd_fops,
711 };
712
hd_interrupt(int irq,void * dev_id,struct pt_regs * regs)713 static void hd_interrupt(int irq, void *dev_id, struct pt_regs *regs)
714 {
715 void (*handler)(void) = DEVICE_INTR;
716
717 DEVICE_INTR = NULL;
718 del_timer(&device_timer);
719 if (!handler)
720 handler = unexpected_hd_interrupt;
721 handler();
722 sti();
723 }
724
725 /*
726 * This is the hard disk IRQ description. The SA_INTERRUPT in sa_flags
727 * means we run the IRQ-handler with interrupts disabled: this is bad for
728 * interrupt latency, but anything else has led to problems on some
729 * machines.
730 *
731 * We enable interrupts in some of the routines after making sure it's
732 * safe.
733 */
hd_geninit(void)734 static void __init hd_geninit(void)
735 {
736 int drive;
737
738 for(drive=0; drive < (MAX_HD << 6); drive++) {
739 hd_blocksizes[drive] = 1024;
740 hd_hardsectsizes[drive] = 512;
741 hd_maxsect[drive]=255;
742 }
743 blksize_size[MAJOR_NR] = hd_blocksizes;
744 hardsect_size[MAJOR_NR] = hd_hardsectsizes;
745 max_sectors[MAJOR_NR] = hd_maxsect;
746
747 #ifdef __i386__
748 if (!NR_HD) {
749 extern struct drive_info drive_info;
750 unsigned char *BIOS = (unsigned char *) &drive_info;
751 unsigned long flags;
752 int cmos_disks;
753
754 for (drive=0 ; drive<2 ; drive++) {
755 hd_info[drive].cyl = *(unsigned short *) BIOS;
756 hd_info[drive].head = *(2+BIOS);
757 hd_info[drive].wpcom = *(unsigned short *) (5+BIOS);
758 hd_info[drive].ctl = *(8+BIOS);
759 hd_info[drive].lzone = *(unsigned short *) (12+BIOS);
760 hd_info[drive].sect = *(14+BIOS);
761 #ifdef does_not_work_for_everybody_with_scsi_but_helps_ibm_vp
762 if (hd_info[drive].cyl && NR_HD == drive)
763 NR_HD++;
764 #endif
765 BIOS += 16;
766 }
767
768 /*
769 We query CMOS about hard disks : it could be that
770 we have a SCSI/ESDI/etc controller that is BIOS
771 compatible with ST-506, and thus showing up in our
772 BIOS table, but not register compatible, and therefore
773 not present in CMOS.
774
775 Furthermore, we will assume that our ST-506 drives
776 <if any> are the primary drives in the system, and
777 the ones reflected as drive 1 or 2.
778
779 The first drive is stored in the high nibble of CMOS
780 byte 0x12, the second in the low nibble. This will be
781 either a 4 bit drive type or 0xf indicating use byte 0x19
782 for an 8 bit type, drive 1, 0x1a for drive 2 in CMOS.
783
784 Needless to say, a non-zero value means we have
785 an AT controller hard disk for that drive.
786
787 Currently the rtc_lock is a bit academic since this
788 driver is non-modular, but someday... ? Paul G.
789 */
790
791 spin_lock_irqsave(&rtc_lock, flags);
792 cmos_disks = CMOS_READ(0x12);
793 spin_unlock_irqrestore(&rtc_lock, flags);
794
795 if (cmos_disks & 0xf0) {
796 if (cmos_disks & 0x0f)
797 NR_HD = 2;
798 else
799 NR_HD = 1;
800 }
801 }
802 #endif /* __i386__ */
803 #ifdef __arm__
804 if (!NR_HD) {
805 /* We don't know anything about the drive. This means
806 * that you *MUST* specify the drive parameters to the
807 * kernel yourself.
808 */
809 printk("hd: no drives specified - use hd=cyl,head,sectors"
810 " on kernel command line\n");
811 }
812 #endif
813
814 for (drive=0 ; drive < NR_HD ; drive++) {
815 hd[drive<<6].nr_sects = hd_info[drive].head *
816 hd_info[drive].sect * hd_info[drive].cyl;
817 printk ("hd%c: %ldMB, CHS=%d/%d/%d\n", drive+'a',
818 hd[drive<<6].nr_sects / 2048, hd_info[drive].cyl,
819 hd_info[drive].head, hd_info[drive].sect);
820 }
821 if (!NR_HD)
822 return;
823
824 if (request_irq(HD_IRQ, hd_interrupt, SA_INTERRUPT, "hd", NULL)) {
825 printk("hd: unable to get IRQ%d for the hard disk driver\n",
826 HD_IRQ);
827 NR_HD = 0;
828 return;
829 }
830 request_region(HD_DATA, 8, "hd");
831 request_region(HD_CMD, 1, "hd(cmd)");
832
833 hd_gendisk.nr_real = NR_HD;
834
835 for(drive=0; drive < NR_HD; drive++)
836 register_disk(&hd_gendisk, MKDEV(MAJOR_NR,drive<<6), 1<<6,
837 &hd_fops, hd_info[drive].head * hd_info[drive].sect *
838 hd_info[drive].cyl);
839 }
840
hd_init(void)841 int __init hd_init(void)
842 {
843 if (devfs_register_blkdev(MAJOR_NR,"hd",&hd_fops)) {
844 printk("hd: unable to get major %d for hard disk\n",MAJOR_NR);
845 return -1;
846 }
847 blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), DEVICE_REQUEST);
848 read_ahead[MAJOR_NR] = 8; /* 8 sector (4kB) read-ahead */
849 add_gendisk(&hd_gendisk);
850 init_timer(&device_timer);
851 device_timer.function = hd_times_out;
852 hd_geninit();
853 return 0;
854 }
855
856 #define DEVICE_BUSY busy[target]
857 #define USAGE access_count[target]
858 #define CAPACITY (hd_info[target].head*hd_info[target].sect*hd_info[target].cyl)
859 /* We assume that the BIOS parameters do not change, so the disk capacity
860 will not change */
861 #undef MAYBE_REINIT
862 #define GENDISK_STRUCT hd_gendisk
863
864 /*
865 * This routine is called to flush all partitions and partition tables
866 * for a changed disk, and then re-read the new partition table.
867 * If we are revalidating a disk because of a media change, then we
868 * enter with usage == 0. If we are using an ioctl, we automatically have
869 * usage == 1 (we need an open channel to use an ioctl :-), so this
870 * is our limit.
871 */
revalidate_hddisk(kdev_t dev,int maxusage)872 static int revalidate_hddisk(kdev_t dev, int maxusage)
873 {
874 int target;
875 struct gendisk * gdev;
876 int max_p;
877 int start;
878 int i;
879 long flags;
880
881 target = DEVICE_NR(dev);
882 gdev = &GENDISK_STRUCT;
883
884 spin_lock_irqsave(&io_request_lock, flags);
885 if (DEVICE_BUSY || USAGE > maxusage) {
886 spin_unlock_irqrestore(&io_request_lock, flags);
887 return -EBUSY;
888 }
889 DEVICE_BUSY = 1;
890 spin_unlock_irqrestore(&io_request_lock, flags);
891
892 max_p = gdev->max_p;
893 start = target << gdev->minor_shift;
894
895 for (i=max_p - 1; i >=0 ; i--) {
896 int minor = start + i;
897 invalidate_device(MKDEV(MAJOR_NR, minor), 1);
898 gdev->part[minor].start_sect = 0;
899 gdev->part[minor].nr_sects = 0;
900 }
901
902 #ifdef MAYBE_REINIT
903 MAYBE_REINIT;
904 #endif
905
906 grok_partitions(gdev, target, 1<<6, CAPACITY);
907
908 DEVICE_BUSY = 0;
909 wake_up(&busy_wait);
910 return 0;
911 }
912
parse_hd_setup(char * line)913 static int parse_hd_setup (char *line) {
914 int ints[6];
915
916 (void) get_options(line, ARRAY_SIZE(ints), ints);
917 hd_setup(NULL, ints);
918
919 return 1;
920 }
921 __setup("hd=", parse_hd_setup);
922
923 module_init(hd_init);
924