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