ide-tape.c revision 71294cf93d22ceaa75448cc6ebee2c65897be8c2
1/*
2 * IDE ATAPI streaming tape driver.
3 *
4 * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
5 * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
6 *
7 * This driver was constructed as a student project in the software laboratory
8 * of the faculty of electrical engineering in the Technion - Israel's
9 * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
10 *
11 * It is hereby placed under the terms of the GNU general public license.
12 * (See linux/COPYING).
13 *
14 * For a historical changelog see
15 * Documentation/ide/ChangeLog.ide-tape.1995-2002
16 */
17
18#define DRV_NAME "ide-tape"
19
20#define IDETAPE_VERSION "1.20"
21
22#include <linux/module.h>
23#include <linux/types.h>
24#include <linux/string.h>
25#include <linux/kernel.h>
26#include <linux/delay.h>
27#include <linux/timer.h>
28#include <linux/mm.h>
29#include <linux/interrupt.h>
30#include <linux/jiffies.h>
31#include <linux/major.h>
32#include <linux/errno.h>
33#include <linux/genhd.h>
34#include <linux/slab.h>
35#include <linux/pci.h>
36#include <linux/ide.h>
37#include <linux/smp_lock.h>
38#include <linux/completion.h>
39#include <linux/bitops.h>
40#include <linux/mutex.h>
41#include <scsi/scsi.h>
42
43#include <asm/byteorder.h>
44#include <linux/irq.h>
45#include <linux/uaccess.h>
46#include <linux/io.h>
47#include <asm/unaligned.h>
48#include <linux/mtio.h>
49
50enum {
51	/* output errors only */
52	DBG_ERR =		(1 << 0),
53	/* output all sense key/asc */
54	DBG_SENSE =		(1 << 1),
55	/* info regarding all chrdev-related procedures */
56	DBG_CHRDEV =		(1 << 2),
57	/* all remaining procedures */
58	DBG_PROCS =		(1 << 3),
59};
60
61/* define to see debug info */
62#define IDETAPE_DEBUG_LOG		0
63
64#if IDETAPE_DEBUG_LOG
65#define debug_log(lvl, fmt, args...)			\
66{							\
67	if (tape->debug_mask & lvl)			\
68	printk(KERN_INFO "ide-tape: " fmt, ## args);	\
69}
70#else
71#define debug_log(lvl, fmt, args...) do {} while (0)
72#endif
73
74/**************************** Tunable parameters *****************************/
75/*
76 * After each failed packet command we issue a request sense command and retry
77 * the packet command IDETAPE_MAX_PC_RETRIES times.
78 *
79 * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
80 */
81#define IDETAPE_MAX_PC_RETRIES		3
82
83/*
84 * The following parameter is used to select the point in the internal tape fifo
85 * in which we will start to refill the buffer. Decreasing the following
86 * parameter will improve the system's latency and interactive response, while
87 * using a high value might improve system throughput.
88 */
89#define IDETAPE_FIFO_THRESHOLD		2
90
91/*
92 * DSC polling parameters.
93 *
94 * Polling for DSC (a single bit in the status register) is a very important
95 * function in ide-tape. There are two cases in which we poll for DSC:
96 *
97 * 1. Before a read/write packet command, to ensure that we can transfer data
98 * from/to the tape's data buffers, without causing an actual media access.
99 * In case the tape is not ready yet, we take out our request from the device
100 * request queue, so that ide.c could service requests from the other device
101 * on the same interface in the meantime.
102 *
103 * 2. After the successful initialization of a "media access packet command",
104 * which is a command that can take a long time to complete (the interval can
105 * range from several seconds to even an hour). Again, we postpone our request
106 * in the middle to free the bus for the other device. The polling frequency
107 * here should be lower than the read/write frequency since those media access
108 * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
109 * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
110 * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
111 *
112 * We also set a timeout for the timer, in case something goes wrong. The
113 * timeout should be longer then the maximum execution time of a tape operation.
114 */
115
116/* DSC timings. */
117#define IDETAPE_DSC_RW_MIN		5*HZ/100	/* 50 msec */
118#define IDETAPE_DSC_RW_MAX		40*HZ/100	/* 400 msec */
119#define IDETAPE_DSC_RW_TIMEOUT		2*60*HZ		/* 2 minutes */
120#define IDETAPE_DSC_MA_FAST		2*HZ		/* 2 seconds */
121#define IDETAPE_DSC_MA_THRESHOLD	5*60*HZ		/* 5 minutes */
122#define IDETAPE_DSC_MA_SLOW		30*HZ		/* 30 seconds */
123#define IDETAPE_DSC_MA_TIMEOUT		2*60*60*HZ	/* 2 hours */
124
125/*************************** End of tunable parameters ***********************/
126
127/* tape directions */
128enum {
129	IDETAPE_DIR_NONE  = (1 << 0),
130	IDETAPE_DIR_READ  = (1 << 1),
131	IDETAPE_DIR_WRITE = (1 << 2),
132};
133
134/* Tape door status */
135#define DOOR_UNLOCKED			0
136#define DOOR_LOCKED			1
137#define DOOR_EXPLICITLY_LOCKED		2
138
139/* Some defines for the SPACE command */
140#define IDETAPE_SPACE_OVER_FILEMARK	1
141#define IDETAPE_SPACE_TO_EOD		3
142
143/* Some defines for the LOAD UNLOAD command */
144#define IDETAPE_LU_LOAD_MASK		1
145#define IDETAPE_LU_RETENSION_MASK	2
146#define IDETAPE_LU_EOT_MASK		4
147
148/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
149#define IDETAPE_BLOCK_DESCRIPTOR	0
150#define IDETAPE_CAPABILITIES_PAGE	0x2a
151
152/*
153 * Most of our global data which we need to save even as we leave the driver due
154 * to an interrupt or a timer event is stored in the struct defined below.
155 */
156typedef struct ide_tape_obj {
157	ide_drive_t		*drive;
158	struct ide_driver	*driver;
159	struct gendisk		*disk;
160	struct device		dev;
161
162	/* used by REQ_IDETAPE_{READ,WRITE} requests */
163	struct ide_atapi_pc queued_pc;
164
165	/*
166	 * DSC polling variables.
167	 *
168	 * While polling for DSC we use postponed_rq to postpone the current
169	 * request so that ide.c will be able to service pending requests on the
170	 * other device. Note that at most we will have only one DSC (usually
171	 * data transfer) request in the device request queue.
172	 */
173	struct request *postponed_rq;
174	/* The time in which we started polling for DSC */
175	unsigned long dsc_polling_start;
176	/* Timer used to poll for dsc */
177	struct timer_list dsc_timer;
178	/* Read/Write dsc polling frequency */
179	unsigned long best_dsc_rw_freq;
180	unsigned long dsc_poll_freq;
181	unsigned long dsc_timeout;
182
183	/* Read position information */
184	u8 partition;
185	/* Current block */
186	unsigned int first_frame;
187
188	/* Last error information */
189	u8 sense_key, asc, ascq;
190
191	/* Character device operation */
192	unsigned int minor;
193	/* device name */
194	char name[4];
195	/* Current character device data transfer direction */
196	u8 chrdev_dir;
197
198	/* tape block size, usually 512 or 1024 bytes */
199	unsigned short blk_size;
200	int user_bs_factor;
201
202	/* Copy of the tape's Capabilities and Mechanical Page */
203	u8 caps[20];
204
205	/*
206	 * Active data transfer request parameters.
207	 *
208	 * At most, there is only one ide-tape originated data transfer request
209	 * in the device request queue. This allows ide.c to easily service
210	 * requests from the other device when we postpone our active request.
211	 */
212
213	/* Data buffer size chosen based on the tape's recommendation */
214	int buffer_size;
215	/* Staging buffer of buffer_size bytes */
216	void *buf;
217	/* The read/write cursor */
218	void *cur;
219	/* The number of valid bytes in buf */
220	size_t valid;
221
222	/* Measures average tape speed */
223	unsigned long avg_time;
224	int avg_size;
225	int avg_speed;
226
227	/* the door is currently locked */
228	int door_locked;
229	/* the tape hardware is write protected */
230	char drv_write_prot;
231	/* the tape is write protected (hardware or opened as read-only) */
232	char write_prot;
233
234	u32 debug_mask;
235} idetape_tape_t;
236
237static DEFINE_MUTEX(idetape_ref_mutex);
238
239static struct class *idetape_sysfs_class;
240
241static void ide_tape_release(struct device *);
242
243static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
244{
245	struct ide_tape_obj *tape = NULL;
246
247	mutex_lock(&idetape_ref_mutex);
248	tape = ide_drv_g(disk, ide_tape_obj);
249	if (tape) {
250		if (ide_device_get(tape->drive))
251			tape = NULL;
252		else
253			get_device(&tape->dev);
254	}
255	mutex_unlock(&idetape_ref_mutex);
256	return tape;
257}
258
259static void ide_tape_put(struct ide_tape_obj *tape)
260{
261	ide_drive_t *drive = tape->drive;
262
263	mutex_lock(&idetape_ref_mutex);
264	put_device(&tape->dev);
265	ide_device_put(drive);
266	mutex_unlock(&idetape_ref_mutex);
267}
268
269/*
270 * The variables below are used for the character device interface. Additional
271 * state variables are defined in our ide_drive_t structure.
272 */
273static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
274
275static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
276{
277	struct ide_tape_obj *tape = NULL;
278
279	mutex_lock(&idetape_ref_mutex);
280	tape = idetape_devs[i];
281	if (tape)
282		get_device(&tape->dev);
283	mutex_unlock(&idetape_ref_mutex);
284	return tape;
285}
286
287/*
288 * called on each failed packet command retry to analyze the request sense. We
289 * currently do not utilize this information.
290 */
291static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
292{
293	idetape_tape_t *tape = drive->driver_data;
294	struct ide_atapi_pc *pc = drive->failed_pc;
295
296	tape->sense_key = sense[2] & 0xF;
297	tape->asc       = sense[12];
298	tape->ascq      = sense[13];
299
300	debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
301		 pc->c[0], tape->sense_key, tape->asc, tape->ascq);
302
303	/* Correct pc->xferred by asking the tape.	 */
304	if (pc->flags & PC_FLAG_DMA_ERROR)
305		pc->xferred = pc->req_xfer -
306			tape->blk_size *
307			get_unaligned_be32(&sense[3]);
308
309	/*
310	 * If error was the result of a zero-length read or write command,
311	 * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
312	 * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
313	 */
314	if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
315	    /* length == 0 */
316	    && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
317		if (tape->sense_key == 5) {
318			/* don't report an error, everything's ok */
319			pc->error = 0;
320			/* don't retry read/write */
321			pc->flags |= PC_FLAG_ABORT;
322		}
323	}
324	if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
325		pc->error = IDE_DRV_ERROR_FILEMARK;
326		pc->flags |= PC_FLAG_ABORT;
327	}
328	if (pc->c[0] == WRITE_6) {
329		if ((sense[2] & 0x40) || (tape->sense_key == 0xd
330		     && tape->asc == 0x0 && tape->ascq == 0x2)) {
331			pc->error = IDE_DRV_ERROR_EOD;
332			pc->flags |= PC_FLAG_ABORT;
333		}
334	}
335	if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
336		if (tape->sense_key == 8) {
337			pc->error = IDE_DRV_ERROR_EOD;
338			pc->flags |= PC_FLAG_ABORT;
339		}
340		if (!(pc->flags & PC_FLAG_ABORT) &&
341		    pc->xferred)
342			pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
343	}
344}
345
346static void ide_tape_handle_dsc(ide_drive_t *);
347
348static int ide_tape_callback(ide_drive_t *drive, int dsc)
349{
350	idetape_tape_t *tape = drive->driver_data;
351	struct ide_atapi_pc *pc = drive->pc;
352	struct request *rq = drive->hwif->rq;
353	int uptodate = pc->error ? 0 : 1;
354	int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
355
356	debug_log(DBG_PROCS, "Enter %s\n", __func__);
357
358	if (dsc)
359		ide_tape_handle_dsc(drive);
360
361	if (drive->failed_pc == pc)
362		drive->failed_pc = NULL;
363
364	if (pc->c[0] == REQUEST_SENSE) {
365		if (uptodate)
366			idetape_analyze_error(drive, pc->buf);
367		else
368			printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
369					"itself - Aborting request!\n");
370	} else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
371		int blocks = pc->xferred / tape->blk_size;
372
373		tape->avg_size += blocks * tape->blk_size;
374
375		if (time_after_eq(jiffies, tape->avg_time + HZ)) {
376			tape->avg_speed = tape->avg_size * HZ /
377				(jiffies - tape->avg_time) / 1024;
378			tape->avg_size = 0;
379			tape->avg_time = jiffies;
380		}
381
382		tape->first_frame += blocks;
383		rq->data_len -= blocks * tape->blk_size;
384
385		if (pc->error) {
386			uptodate = 0;
387			err = pc->error;
388		}
389	} else if (pc->c[0] == READ_POSITION && uptodate) {
390		u8 *readpos = pc->buf;
391
392		debug_log(DBG_SENSE, "BOP - %s\n",
393				(readpos[0] & 0x80) ? "Yes" : "No");
394		debug_log(DBG_SENSE, "EOP - %s\n",
395				(readpos[0] & 0x40) ? "Yes" : "No");
396
397		if (readpos[0] & 0x4) {
398			printk(KERN_INFO "ide-tape: Block location is unknown"
399					 "to the tape\n");
400			clear_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
401			uptodate = 0;
402			err = IDE_DRV_ERROR_GENERAL;
403		} else {
404			debug_log(DBG_SENSE, "Block Location - %u\n",
405					be32_to_cpup((__be32 *)&readpos[4]));
406
407			tape->partition = readpos[1];
408			tape->first_frame = be32_to_cpup((__be32 *)&readpos[4]);
409			set_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
410		}
411	}
412
413	rq->errors = err;
414
415	return uptodate;
416}
417
418/*
419 * Postpone the current request so that ide.c will be able to service requests
420 * from another device on the same port while we are polling for DSC.
421 */
422static void idetape_postpone_request(ide_drive_t *drive)
423{
424	idetape_tape_t *tape = drive->driver_data;
425
426	debug_log(DBG_PROCS, "Enter %s\n", __func__);
427
428	tape->postponed_rq = drive->hwif->rq;
429
430	ide_stall_queue(drive, tape->dsc_poll_freq);
431}
432
433static void ide_tape_handle_dsc(ide_drive_t *drive)
434{
435	idetape_tape_t *tape = drive->driver_data;
436
437	/* Media access command */
438	tape->dsc_polling_start = jiffies;
439	tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
440	tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
441	/* Allow ide.c to handle other requests */
442	idetape_postpone_request(drive);
443}
444
445/*
446 * Packet Command Interface
447 *
448 * The current Packet Command is available in drive->pc, and will not change
449 * until we finish handling it. Each packet command is associated with a
450 * callback function that will be called when the command is finished.
451 *
452 * The handling will be done in three stages:
453 *
454 * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
455 * the interrupt handler to ide_pc_intr.
456 *
457 * 2. On each interrupt, ide_pc_intr will be called. This step will be
458 * repeated until the device signals us that no more interrupts will be issued.
459 *
460 * 3. ATAPI Tape media access commands have immediate status with a delayed
461 * process. In case of a successful initiation of a media access packet command,
462 * the DSC bit will be set when the actual execution of the command is finished.
463 * Since the tape drive will not issue an interrupt, we have to poll for this
464 * event. In this case, we define the request as "low priority request" by
465 * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
466 * exit the driver.
467 *
468 * ide.c will then give higher priority to requests which originate from the
469 * other device, until will change rq_status to RQ_ACTIVE.
470 *
471 * 4. When the packet command is finished, it will be checked for errors.
472 *
473 * 5. In case an error was found, we queue a request sense packet command in
474 * front of the request queue and retry the operation up to
475 * IDETAPE_MAX_PC_RETRIES times.
476 *
477 * 6. In case no error was found, or we decided to give up and not to retry
478 * again, the callback function will be called and then we will handle the next
479 * request.
480 */
481
482static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
483					 struct ide_cmd *cmd,
484					 struct ide_atapi_pc *pc)
485{
486	idetape_tape_t *tape = drive->driver_data;
487
488	if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
489		drive->failed_pc = pc;
490
491	/* Set the current packet command */
492	drive->pc = pc;
493
494	if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
495		(pc->flags & PC_FLAG_ABORT)) {
496		unsigned int done = blk_rq_bytes(drive->hwif->rq);
497
498		/*
499		 * We will "abort" retrying a packet command in case legitimate
500		 * error code was received (crossing a filemark, or end of the
501		 * media, for example).
502		 */
503		if (!(pc->flags & PC_FLAG_ABORT)) {
504			if (!(pc->c[0] == TEST_UNIT_READY &&
505			      tape->sense_key == 2 && tape->asc == 4 &&
506			     (tape->ascq == 1 || tape->ascq == 8))) {
507				printk(KERN_ERR "ide-tape: %s: I/O error, "
508						"pc = %2x, key = %2x, "
509						"asc = %2x, ascq = %2x\n",
510						tape->name, pc->c[0],
511						tape->sense_key, tape->asc,
512						tape->ascq);
513			}
514			/* Giving up */
515			pc->error = IDE_DRV_ERROR_GENERAL;
516		}
517
518		drive->failed_pc = NULL;
519		drive->pc_callback(drive, 0);
520		ide_complete_rq(drive, -EIO, done);
521		return ide_stopped;
522	}
523	debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
524
525	pc->retries++;
526
527	return ide_issue_pc(drive, cmd);
528}
529
530/* A mode sense command is used to "sense" tape parameters. */
531static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
532{
533	ide_init_pc(pc);
534	pc->c[0] = MODE_SENSE;
535	if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
536		/* DBD = 1 - Don't return block descriptors */
537		pc->c[1] = 8;
538	pc->c[2] = page_code;
539	/*
540	 * Changed pc->c[3] to 0 (255 will at best return unused info).
541	 *
542	 * For SCSI this byte is defined as subpage instead of high byte
543	 * of length and some IDE drives seem to interpret it this way
544	 * and return an error when 255 is used.
545	 */
546	pc->c[3] = 0;
547	/* We will just discard data in that case */
548	pc->c[4] = 255;
549	if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
550		pc->req_xfer = 12;
551	else if (page_code == IDETAPE_CAPABILITIES_PAGE)
552		pc->req_xfer = 24;
553	else
554		pc->req_xfer = 50;
555}
556
557static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
558{
559	ide_hwif_t *hwif = drive->hwif;
560	idetape_tape_t *tape = drive->driver_data;
561	struct ide_atapi_pc *pc = drive->pc;
562	u8 stat;
563
564	stat = hwif->tp_ops->read_status(hwif);
565
566	if (stat & ATA_DSC) {
567		if (stat & ATA_ERR) {
568			/* Error detected */
569			if (pc->c[0] != TEST_UNIT_READY)
570				printk(KERN_ERR "ide-tape: %s: I/O error, ",
571						tape->name);
572			/* Retry operation */
573			ide_retry_pc(drive);
574			return ide_stopped;
575		}
576		pc->error = 0;
577	} else {
578		pc->error = IDE_DRV_ERROR_GENERAL;
579		drive->failed_pc = NULL;
580	}
581	drive->pc_callback(drive, 0);
582	return ide_stopped;
583}
584
585static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
586				   struct ide_atapi_pc *pc, struct request *rq,
587				   u8 opcode)
588{
589	unsigned int length = rq->nr_sectors;
590
591	ide_init_pc(pc);
592	put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
593	pc->c[1] = 1;
594	pc->bh = NULL;
595	pc->buf = NULL;
596	pc->buf_size = length * tape->blk_size;
597	pc->req_xfer = pc->buf_size;
598	if (pc->req_xfer == tape->buffer_size)
599		pc->flags |= PC_FLAG_DMA_OK;
600
601	if (opcode == READ_6)
602		pc->c[0] = READ_6;
603	else if (opcode == WRITE_6) {
604		pc->c[0] = WRITE_6;
605		pc->flags |= PC_FLAG_WRITING;
606	}
607
608	memcpy(rq->cmd, pc->c, 12);
609}
610
611static ide_startstop_t idetape_do_request(ide_drive_t *drive,
612					  struct request *rq, sector_t block)
613{
614	ide_hwif_t *hwif = drive->hwif;
615	idetape_tape_t *tape = drive->driver_data;
616	struct ide_atapi_pc *pc = NULL;
617	struct request *postponed_rq = tape->postponed_rq;
618	struct ide_cmd cmd;
619	u8 stat;
620
621	debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %lu\n"
622		  (unsigned long long)rq->sector, rq->nr_sectors);
623
624	if (!(blk_special_request(rq) || blk_sense_request(rq))) {
625		/* We do not support buffer cache originated requests. */
626		printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
627			"request queue (%d)\n", drive->name, rq->cmd_type);
628		if (blk_fs_request(rq) == 0 && rq->errors == 0)
629			rq->errors = -EIO;
630		ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
631		return ide_stopped;
632	}
633
634	/* Retry a failed packet command */
635	if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
636		pc = drive->failed_pc;
637		goto out;
638	}
639
640	if (postponed_rq != NULL)
641		if (rq != postponed_rq) {
642			printk(KERN_ERR "ide-tape: ide-tape.c bug - "
643					"Two DSC requests were queued\n");
644			drive->failed_pc = NULL;
645			rq->errors = 0;
646			ide_complete_rq(drive, 0, blk_rq_bytes(rq));
647			return ide_stopped;
648		}
649
650	tape->postponed_rq = NULL;
651
652	/*
653	 * If the tape is still busy, postpone our request and service
654	 * the other device meanwhile.
655	 */
656	stat = hwif->tp_ops->read_status(hwif);
657
658	if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
659	    (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
660		set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
661
662	if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
663		set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
664		drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
665	}
666
667	if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) &&
668	    (stat & ATA_DSC) == 0) {
669		if (postponed_rq == NULL) {
670			tape->dsc_polling_start = jiffies;
671			tape->dsc_poll_freq = tape->best_dsc_rw_freq;
672			tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
673		} else if (time_after(jiffies, tape->dsc_timeout)) {
674			printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
675				tape->name);
676			if (rq->cmd[13] & REQ_IDETAPE_PC2) {
677				idetape_media_access_finished(drive);
678				return ide_stopped;
679			} else {
680				return ide_do_reset(drive);
681			}
682		} else if (time_after(jiffies,
683					tape->dsc_polling_start +
684					IDETAPE_DSC_MA_THRESHOLD))
685			tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
686		idetape_postpone_request(drive);
687		return ide_stopped;
688	}
689	if (rq->cmd[13] & REQ_IDETAPE_READ) {
690		pc = &tape->queued_pc;
691		ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
692		goto out;
693	}
694	if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
695		pc = &tape->queued_pc;
696		ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
697		goto out;
698	}
699	if (rq->cmd[13] & REQ_IDETAPE_PC1) {
700		pc = (struct ide_atapi_pc *)rq->special;
701		rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
702		rq->cmd[13] |= REQ_IDETAPE_PC2;
703		goto out;
704	}
705	if (rq->cmd[13] & REQ_IDETAPE_PC2) {
706		idetape_media_access_finished(drive);
707		return ide_stopped;
708	}
709	BUG();
710
711out:
712	/* prepare sense request for this command */
713	ide_prep_sense(drive, rq);
714
715	memset(&cmd, 0, sizeof(cmd));
716
717	if (rq_data_dir(rq))
718		cmd.tf_flags |= IDE_TFLAG_WRITE;
719
720	cmd.rq = rq;
721
722	ide_init_sg_cmd(&cmd, pc->req_xfer);
723	ide_map_sg(drive, &cmd);
724
725	return ide_tape_issue_pc(drive, &cmd, pc);
726}
727
728/*
729 * Write a filemark if write_filemark=1. Flush the device buffers without
730 * writing a filemark otherwise.
731 */
732static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
733		struct ide_atapi_pc *pc, int write_filemark)
734{
735	ide_init_pc(pc);
736	pc->c[0] = WRITE_FILEMARKS;
737	pc->c[4] = write_filemark;
738	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
739}
740
741static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
742{
743	idetape_tape_t *tape = drive->driver_data;
744	struct gendisk *disk = tape->disk;
745	int load_attempted = 0;
746
747	/* Wait for the tape to become ready */
748	set_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
749	timeout += jiffies;
750	while (time_before(jiffies, timeout)) {
751		if (ide_do_test_unit_ready(drive, disk) == 0)
752			return 0;
753		if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
754		    || (tape->asc == 0x3A)) {
755			/* no media */
756			if (load_attempted)
757				return -ENOMEDIUM;
758			ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
759			load_attempted = 1;
760		/* not about to be ready */
761		} else if (!(tape->sense_key == 2 && tape->asc == 4 &&
762			     (tape->ascq == 1 || tape->ascq == 8)))
763			return -EIO;
764		msleep(100);
765	}
766	return -EIO;
767}
768
769static int idetape_flush_tape_buffers(ide_drive_t *drive)
770{
771	struct ide_tape_obj *tape = drive->driver_data;
772	struct ide_atapi_pc pc;
773	int rc;
774
775	idetape_create_write_filemark_cmd(drive, &pc, 0);
776	rc = ide_queue_pc_tail(drive, tape->disk, &pc);
777	if (rc)
778		return rc;
779	idetape_wait_ready(drive, 60 * 5 * HZ);
780	return 0;
781}
782
783static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc)
784{
785	ide_init_pc(pc);
786	pc->c[0] = READ_POSITION;
787	pc->req_xfer = 20;
788}
789
790static int idetape_read_position(ide_drive_t *drive)
791{
792	idetape_tape_t *tape = drive->driver_data;
793	struct ide_atapi_pc pc;
794	int position;
795
796	debug_log(DBG_PROCS, "Enter %s\n", __func__);
797
798	idetape_create_read_position_cmd(&pc);
799	if (ide_queue_pc_tail(drive, tape->disk, &pc))
800		return -1;
801	position = tape->first_frame;
802	return position;
803}
804
805static void idetape_create_locate_cmd(ide_drive_t *drive,
806		struct ide_atapi_pc *pc,
807		unsigned int block, u8 partition, int skip)
808{
809	ide_init_pc(pc);
810	pc->c[0] = POSITION_TO_ELEMENT;
811	pc->c[1] = 2;
812	put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
813	pc->c[8] = partition;
814	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
815}
816
817static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
818{
819	idetape_tape_t *tape = drive->driver_data;
820
821	if (tape->chrdev_dir != IDETAPE_DIR_READ)
822		return;
823
824	clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags);
825	tape->valid = 0;
826	if (tape->buf != NULL) {
827		kfree(tape->buf);
828		tape->buf = NULL;
829	}
830
831	tape->chrdev_dir = IDETAPE_DIR_NONE;
832}
833
834/*
835 * Position the tape to the requested block using the LOCATE packet command.
836 * A READ POSITION command is then issued to check where we are positioned. Like
837 * all higher level operations, we queue the commands at the tail of the request
838 * queue and wait for their completion.
839 */
840static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
841		u8 partition, int skip)
842{
843	idetape_tape_t *tape = drive->driver_data;
844	struct gendisk *disk = tape->disk;
845	int retval;
846	struct ide_atapi_pc pc;
847
848	if (tape->chrdev_dir == IDETAPE_DIR_READ)
849		__ide_tape_discard_merge_buffer(drive);
850	idetape_wait_ready(drive, 60 * 5 * HZ);
851	idetape_create_locate_cmd(drive, &pc, block, partition, skip);
852	retval = ide_queue_pc_tail(drive, disk, &pc);
853	if (retval)
854		return (retval);
855
856	idetape_create_read_position_cmd(&pc);
857	return ide_queue_pc_tail(drive, disk, &pc);
858}
859
860static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
861					  int restore_position)
862{
863	idetape_tape_t *tape = drive->driver_data;
864	int seek, position;
865
866	__ide_tape_discard_merge_buffer(drive);
867	if (restore_position) {
868		position = idetape_read_position(drive);
869		seek = position > 0 ? position : 0;
870		if (idetape_position_tape(drive, seek, 0, 0)) {
871			printk(KERN_INFO "ide-tape: %s: position_tape failed in"
872					 " %s\n", tape->name, __func__);
873			return;
874		}
875	}
876}
877
878/*
879 * Generate a read/write request for the block device interface and wait for it
880 * to be serviced.
881 */
882static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
883{
884	idetape_tape_t *tape = drive->driver_data;
885	struct request *rq;
886	int ret;
887
888	debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
889	BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
890	BUG_ON(size < 0 || size % tape->blk_size);
891
892	rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
893	rq->cmd_type = REQ_TYPE_SPECIAL;
894	rq->cmd[13] = cmd;
895	rq->rq_disk = tape->disk;
896	rq->sector = tape->first_frame;
897
898	if (size) {
899		ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
900				      __GFP_WAIT);
901		if (ret)
902			goto out_put;
903	}
904
905	blk_execute_rq(drive->queue, tape->disk, rq, 0);
906
907	/* calculate the number of transferred bytes and update buffer state */
908	size -= rq->data_len;
909	tape->cur = tape->buf;
910	if (cmd == REQ_IDETAPE_READ)
911		tape->valid = size;
912	else
913		tape->valid = 0;
914
915	ret = size;
916	if (rq->errors == IDE_DRV_ERROR_GENERAL)
917		ret = -EIO;
918out_put:
919	blk_put_request(rq);
920	return ret;
921}
922
923static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
924{
925	ide_init_pc(pc);
926	pc->c[0] = INQUIRY;
927	pc->c[4] = 254;
928	pc->req_xfer = 254;
929}
930
931static void idetape_create_rewind_cmd(ide_drive_t *drive,
932		struct ide_atapi_pc *pc)
933{
934	ide_init_pc(pc);
935	pc->c[0] = REZERO_UNIT;
936	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
937}
938
939static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
940{
941	ide_init_pc(pc);
942	pc->c[0] = ERASE;
943	pc->c[1] = 1;
944	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
945}
946
947static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
948{
949	ide_init_pc(pc);
950	pc->c[0] = SPACE;
951	put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
952	pc->c[1] = cmd;
953	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
954}
955
956/* Queue up a character device originated write request. */
957static int idetape_add_chrdev_write_request(ide_drive_t *drive, int size)
958{
959	debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
960
961	return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, size);
962}
963
964static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
965{
966	idetape_tape_t *tape = drive->driver_data;
967
968	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
969		printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
970				" but we are not writing.\n");
971		return;
972	}
973	if (tape->buf) {
974		size_t aligned = roundup(tape->valid, tape->blk_size);
975
976		memset(tape->cur, 0, aligned - tape->valid);
977		idetape_add_chrdev_write_request(drive, aligned);
978		kfree(tape->buf);
979		tape->buf = NULL;
980	}
981	tape->chrdev_dir = IDETAPE_DIR_NONE;
982}
983
984static int idetape_init_rw(ide_drive_t *drive, int dir)
985{
986	idetape_tape_t *tape = drive->driver_data;
987	int rc;
988
989	BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
990
991	if (tape->chrdev_dir == dir)
992		return 0;
993
994	if (tape->chrdev_dir == IDETAPE_DIR_READ)
995		ide_tape_discard_merge_buffer(drive, 1);
996	else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
997		ide_tape_flush_merge_buffer(drive);
998		idetape_flush_tape_buffers(drive);
999	}
1000
1001	if (tape->buf || tape->valid) {
1002		printk(KERN_ERR "ide-tape: valid should be 0 now\n");
1003		tape->valid = 0;
1004	}
1005
1006	tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1007	if (!tape->buf)
1008		return -ENOMEM;
1009	tape->chrdev_dir = dir;
1010	tape->cur = tape->buf;
1011
1012	/*
1013	 * Issue a 0 rw command to ensure that DSC handshake is
1014	 * switched from completion mode to buffer available mode.  No
1015	 * point in issuing this if DSC overlap isn't supported, some
1016	 * drives (Seagate STT3401A) will return an error.
1017	 */
1018	if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1019		int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
1020						  : REQ_IDETAPE_WRITE;
1021
1022		rc = idetape_queue_rw_tail(drive, cmd, 0);
1023		if (rc < 0) {
1024			kfree(tape->buf);
1025			tape->buf = NULL;
1026			tape->chrdev_dir = IDETAPE_DIR_NONE;
1027			return rc;
1028		}
1029	}
1030
1031	return 0;
1032}
1033
1034/* called from idetape_chrdev_read() to service a chrdev read request. */
1035static int idetape_add_chrdev_read_request(ide_drive_t *drive, int size)
1036{
1037	debug_log(DBG_PROCS, "Enter %s, %d bytes\n", __func__, size);
1038
1039	/* If we are at a filemark, return a read length of 0 */
1040	if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1041		return 0;
1042
1043	idetape_init_rw(drive, IDETAPE_DIR_READ);
1044
1045	return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, size);
1046}
1047
1048static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
1049{
1050	idetape_tape_t *tape = drive->driver_data;
1051
1052	memset(tape->buf, 0, tape->buffer_size);
1053
1054	while (bcount) {
1055		unsigned int count = min(tape->buffer_size, bcount);
1056
1057		idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1058		bcount -= count;
1059	}
1060}
1061
1062/*
1063 * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1064 * currently support only one partition.
1065 */
1066static int idetape_rewind_tape(ide_drive_t *drive)
1067{
1068	struct ide_tape_obj *tape = drive->driver_data;
1069	struct gendisk *disk = tape->disk;
1070	int retval;
1071	struct ide_atapi_pc pc;
1072
1073	debug_log(DBG_SENSE, "Enter %s\n", __func__);
1074
1075	idetape_create_rewind_cmd(drive, &pc);
1076	retval = ide_queue_pc_tail(drive, disk, &pc);
1077	if (retval)
1078		return retval;
1079
1080	idetape_create_read_position_cmd(&pc);
1081	retval = ide_queue_pc_tail(drive, disk, &pc);
1082	if (retval)
1083		return retval;
1084	return 0;
1085}
1086
1087/* mtio.h compatible commands should be issued to the chrdev interface. */
1088static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1089				unsigned long arg)
1090{
1091	idetape_tape_t *tape = drive->driver_data;
1092	void __user *argp = (void __user *)arg;
1093
1094	struct idetape_config {
1095		int dsc_rw_frequency;
1096		int dsc_media_access_frequency;
1097		int nr_stages;
1098	} config;
1099
1100	debug_log(DBG_PROCS, "Enter %s\n", __func__);
1101
1102	switch (cmd) {
1103	case 0x0340:
1104		if (copy_from_user(&config, argp, sizeof(config)))
1105			return -EFAULT;
1106		tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1107		break;
1108	case 0x0350:
1109		config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1110		config.nr_stages = 1;
1111		if (copy_to_user(argp, &config, sizeof(config)))
1112			return -EFAULT;
1113		break;
1114	default:
1115		return -EIO;
1116	}
1117	return 0;
1118}
1119
1120static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1121					int mt_count)
1122{
1123	idetape_tape_t *tape = drive->driver_data;
1124	struct gendisk *disk = tape->disk;
1125	struct ide_atapi_pc pc;
1126	int retval, count = 0;
1127	int sprev = !!(tape->caps[4] & 0x20);
1128
1129	if (mt_count == 0)
1130		return 0;
1131	if (MTBSF == mt_op || MTBSFM == mt_op) {
1132		if (!sprev)
1133			return -EIO;
1134		mt_count = -mt_count;
1135	}
1136
1137	if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1138		tape->valid = 0;
1139		if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1140			++count;
1141		ide_tape_discard_merge_buffer(drive, 0);
1142	}
1143
1144	switch (mt_op) {
1145	case MTFSF:
1146	case MTBSF:
1147		idetape_create_space_cmd(&pc, mt_count - count,
1148					 IDETAPE_SPACE_OVER_FILEMARK);
1149		return ide_queue_pc_tail(drive, disk, &pc);
1150	case MTFSFM:
1151	case MTBSFM:
1152		if (!sprev)
1153			return -EIO;
1154		retval = idetape_space_over_filemarks(drive, MTFSF,
1155						      mt_count - count);
1156		if (retval)
1157			return retval;
1158		count = (MTBSFM == mt_op ? 1 : -1);
1159		return idetape_space_over_filemarks(drive, MTFSF, count);
1160	default:
1161		printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1162				mt_op);
1163		return -EIO;
1164	}
1165}
1166
1167/*
1168 * Our character device read / write functions.
1169 *
1170 * The tape is optimized to maximize throughput when it is transferring an
1171 * integral number of the "continuous transfer limit", which is a parameter of
1172 * the specific tape (26kB on my particular tape, 32kB for Onstream).
1173 *
1174 * As of version 1.3 of the driver, the character device provides an abstract
1175 * continuous view of the media - any mix of block sizes (even 1 byte) on the
1176 * same backup/restore procedure is supported. The driver will internally
1177 * convert the requests to the recommended transfer unit, so that an unmatch
1178 * between the user's block size to the recommended size will only result in a
1179 * (slightly) increased driver overhead, but will no longer hit performance.
1180 * This is not applicable to Onstream.
1181 */
1182static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1183				   size_t count, loff_t *ppos)
1184{
1185	struct ide_tape_obj *tape = file->private_data;
1186	ide_drive_t *drive = tape->drive;
1187	ssize_t bytes_read, temp, actually_read = 0, rc;
1188	ssize_t ret = 0;
1189
1190	debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1191
1192	if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1193		if (test_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags))
1194			if (count > tape->blk_size &&
1195			    (count % tape->blk_size) == 0)
1196				tape->user_bs_factor = count / tape->blk_size;
1197	}
1198	rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1199	if (rc < 0)
1200		return rc;
1201	if (count == 0)
1202		return (0);
1203	if (tape->valid) {
1204		actually_read = min_t(unsigned int, tape->valid, count);
1205		if (copy_to_user(buf, tape->cur, actually_read))
1206			ret = -EFAULT;
1207		buf += actually_read;
1208		count -= actually_read;
1209		tape->cur += actually_read;
1210		tape->valid -= actually_read;
1211	}
1212	while (count >= tape->buffer_size) {
1213		bytes_read = idetape_add_chrdev_read_request(drive,
1214							     tape->buffer_size);
1215		if (bytes_read <= 0)
1216			goto finish;
1217		if (copy_to_user(buf, tape->cur, bytes_read))
1218			ret = -EFAULT;
1219		buf += bytes_read;
1220		count -= bytes_read;
1221		actually_read += bytes_read;
1222	}
1223	if (count) {
1224		bytes_read = idetape_add_chrdev_read_request(drive,
1225							     tape->buffer_size);
1226		if (bytes_read <= 0)
1227			goto finish;
1228		temp = min((unsigned long)count, (unsigned long)bytes_read);
1229		if (copy_to_user(buf, tape->cur, temp))
1230			ret = -EFAULT;
1231		actually_read += temp;
1232		tape->cur += temp;
1233		tape->valid -= temp;
1234	}
1235finish:
1236	if (!actually_read && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) {
1237		debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
1238
1239		idetape_space_over_filemarks(drive, MTFSF, 1);
1240		return 0;
1241	}
1242
1243	return ret ? ret : actually_read;
1244}
1245
1246static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1247				     size_t count, loff_t *ppos)
1248{
1249	struct ide_tape_obj *tape = file->private_data;
1250	ide_drive_t *drive = tape->drive;
1251	ssize_t actually_written = 0;
1252	ssize_t ret = 0;
1253	int rc;
1254
1255	/* The drive is write protected. */
1256	if (tape->write_prot)
1257		return -EACCES;
1258
1259	debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1260
1261	/* Initialize write operation */
1262	rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1263	if (rc < 0)
1264		return rc;
1265	if (count == 0)
1266		return (0);
1267	if (tape->valid < tape->buffer_size) {
1268		actually_written = min_t(unsigned int,
1269					 tape->buffer_size - tape->valid,
1270					 count);
1271		if (copy_from_user(tape->cur, buf, actually_written))
1272			ret = -EFAULT;
1273		buf += actually_written;
1274		count -= actually_written;
1275		tape->cur += actually_written;
1276		tape->valid += actually_written;
1277
1278		if (tape->valid == tape->buffer_size) {
1279			ssize_t retval;
1280			retval = idetape_add_chrdev_write_request(drive,
1281							tape->buffer_size);
1282			if (retval <= 0)
1283				return (retval);
1284		}
1285	}
1286	while (count >= tape->buffer_size) {
1287		ssize_t retval;
1288		if (copy_from_user(tape->cur, buf, tape->buffer_size))
1289			ret = -EFAULT;
1290		buf += tape->buffer_size;
1291		count -= tape->buffer_size;
1292		retval = idetape_add_chrdev_write_request(drive,
1293							  tape->buffer_size);
1294		actually_written += tape->buffer_size;
1295		if (retval <= 0)
1296			return (retval);
1297	}
1298	if (count) {
1299		actually_written += count;
1300		if (copy_from_user(tape->cur, buf, count))
1301			ret = -EFAULT;
1302		tape->cur += count;
1303		tape->valid += count;
1304	}
1305	return ret ? ret : actually_written;
1306}
1307
1308static int idetape_write_filemark(ide_drive_t *drive)
1309{
1310	struct ide_tape_obj *tape = drive->driver_data;
1311	struct ide_atapi_pc pc;
1312
1313	/* Write a filemark */
1314	idetape_create_write_filemark_cmd(drive, &pc, 1);
1315	if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1316		printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1317		return -EIO;
1318	}
1319	return 0;
1320}
1321
1322/*
1323 * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1324 * requested.
1325 *
1326 * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1327 * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1328 * usually not supported.
1329 *
1330 * The following commands are currently not supported:
1331 *
1332 * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1333 * MT_ST_WRITE_THRESHOLD.
1334 */
1335static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1336{
1337	idetape_tape_t *tape = drive->driver_data;
1338	struct gendisk *disk = tape->disk;
1339	struct ide_atapi_pc pc;
1340	int i, retval;
1341
1342	debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
1343			mt_op, mt_count);
1344
1345	switch (mt_op) {
1346	case MTFSF:
1347	case MTFSFM:
1348	case MTBSF:
1349	case MTBSFM:
1350		if (!mt_count)
1351			return 0;
1352		return idetape_space_over_filemarks(drive, mt_op, mt_count);
1353	default:
1354		break;
1355	}
1356
1357	switch (mt_op) {
1358	case MTWEOF:
1359		if (tape->write_prot)
1360			return -EACCES;
1361		ide_tape_discard_merge_buffer(drive, 1);
1362		for (i = 0; i < mt_count; i++) {
1363			retval = idetape_write_filemark(drive);
1364			if (retval)
1365				return retval;
1366		}
1367		return 0;
1368	case MTREW:
1369		ide_tape_discard_merge_buffer(drive, 0);
1370		if (idetape_rewind_tape(drive))
1371			return -EIO;
1372		return 0;
1373	case MTLOAD:
1374		ide_tape_discard_merge_buffer(drive, 0);
1375		return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1376	case MTUNLOAD:
1377	case MTOFFL:
1378		/*
1379		 * If door is locked, attempt to unlock before
1380		 * attempting to eject.
1381		 */
1382		if (tape->door_locked) {
1383			if (!ide_set_media_lock(drive, disk, 0))
1384				tape->door_locked = DOOR_UNLOCKED;
1385		}
1386		ide_tape_discard_merge_buffer(drive, 0);
1387		retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1388		if (!retval)
1389			clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1390		return retval;
1391	case MTNOP:
1392		ide_tape_discard_merge_buffer(drive, 0);
1393		return idetape_flush_tape_buffers(drive);
1394	case MTRETEN:
1395		ide_tape_discard_merge_buffer(drive, 0);
1396		return ide_do_start_stop(drive, disk,
1397			IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1398	case MTEOM:
1399		idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1400		return ide_queue_pc_tail(drive, disk, &pc);
1401	case MTERASE:
1402		(void)idetape_rewind_tape(drive);
1403		idetape_create_erase_cmd(&pc);
1404		return ide_queue_pc_tail(drive, disk, &pc);
1405	case MTSETBLK:
1406		if (mt_count) {
1407			if (mt_count < tape->blk_size ||
1408			    mt_count % tape->blk_size)
1409				return -EIO;
1410			tape->user_bs_factor = mt_count / tape->blk_size;
1411			clear_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1412		} else
1413			set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1414		return 0;
1415	case MTSEEK:
1416		ide_tape_discard_merge_buffer(drive, 0);
1417		return idetape_position_tape(drive,
1418			mt_count * tape->user_bs_factor, tape->partition, 0);
1419	case MTSETPART:
1420		ide_tape_discard_merge_buffer(drive, 0);
1421		return idetape_position_tape(drive, 0, mt_count, 0);
1422	case MTFSR:
1423	case MTBSR:
1424	case MTLOCK:
1425		retval = ide_set_media_lock(drive, disk, 1);
1426		if (retval)
1427			return retval;
1428		tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1429		return 0;
1430	case MTUNLOCK:
1431		retval = ide_set_media_lock(drive, disk, 0);
1432		if (retval)
1433			return retval;
1434		tape->door_locked = DOOR_UNLOCKED;
1435		return 0;
1436	default:
1437		printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1438				mt_op);
1439		return -EIO;
1440	}
1441}
1442
1443/*
1444 * Our character device ioctls. General mtio.h magnetic io commands are
1445 * supported here, and not in the corresponding block interface. Our own
1446 * ide-tape ioctls are supported on both interfaces.
1447 */
1448static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
1449				unsigned int cmd, unsigned long arg)
1450{
1451	struct ide_tape_obj *tape = file->private_data;
1452	ide_drive_t *drive = tape->drive;
1453	struct mtop mtop;
1454	struct mtget mtget;
1455	struct mtpos mtpos;
1456	int block_offset = 0, position = tape->first_frame;
1457	void __user *argp = (void __user *)arg;
1458
1459	debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
1460
1461	if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1462		ide_tape_flush_merge_buffer(drive);
1463		idetape_flush_tape_buffers(drive);
1464	}
1465	if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1466		block_offset = tape->valid /
1467			(tape->blk_size * tape->user_bs_factor);
1468		position = idetape_read_position(drive);
1469		if (position < 0)
1470			return -EIO;
1471	}
1472	switch (cmd) {
1473	case MTIOCTOP:
1474		if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1475			return -EFAULT;
1476		return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1477	case MTIOCGET:
1478		memset(&mtget, 0, sizeof(struct mtget));
1479		mtget.mt_type = MT_ISSCSI2;
1480		mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1481		mtget.mt_dsreg =
1482			((tape->blk_size * tape->user_bs_factor)
1483			 << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1484
1485		if (tape->drv_write_prot)
1486			mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1487
1488		if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1489			return -EFAULT;
1490		return 0;
1491	case MTIOCPOS:
1492		mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1493		if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1494			return -EFAULT;
1495		return 0;
1496	default:
1497		if (tape->chrdev_dir == IDETAPE_DIR_READ)
1498			ide_tape_discard_merge_buffer(drive, 1);
1499		return idetape_blkdev_ioctl(drive, cmd, arg);
1500	}
1501}
1502
1503/*
1504 * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1505 * block size with the reported value.
1506 */
1507static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1508{
1509	idetape_tape_t *tape = drive->driver_data;
1510	struct ide_atapi_pc pc;
1511
1512	idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1513	if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1514		printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1515		if (tape->blk_size == 0) {
1516			printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1517					    "block size, assuming 32k\n");
1518			tape->blk_size = 32768;
1519		}
1520		return;
1521	}
1522	tape->blk_size = (pc.buf[4 + 5] << 16) +
1523				(pc.buf[4 + 6] << 8)  +
1524				 pc.buf[4 + 7];
1525	tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7;
1526}
1527
1528static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1529{
1530	unsigned int minor = iminor(inode), i = minor & ~0xc0;
1531	ide_drive_t *drive;
1532	idetape_tape_t *tape;
1533	int retval;
1534
1535	if (i >= MAX_HWIFS * MAX_DRIVES)
1536		return -ENXIO;
1537
1538	lock_kernel();
1539	tape = ide_tape_chrdev_get(i);
1540	if (!tape) {
1541		unlock_kernel();
1542		return -ENXIO;
1543	}
1544
1545	debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1546
1547	/*
1548	 * We really want to do nonseekable_open(inode, filp); here, but some
1549	 * versions of tar incorrectly call lseek on tapes and bail out if that
1550	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1551	 */
1552	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1553
1554	drive = tape->drive;
1555
1556	filp->private_data = tape;
1557
1558	if (test_and_set_bit(IDE_AFLAG_BUSY, &drive->atapi_flags)) {
1559		retval = -EBUSY;
1560		goto out_put_tape;
1561	}
1562
1563	retval = idetape_wait_ready(drive, 60 * HZ);
1564	if (retval) {
1565		clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1566		printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1567		goto out_put_tape;
1568	}
1569
1570	idetape_read_position(drive);
1571	if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags))
1572		(void)idetape_rewind_tape(drive);
1573
1574	/* Read block size and write protect status from drive. */
1575	ide_tape_get_bsize_from_bdesc(drive);
1576
1577	/* Set write protect flag if device is opened as read-only. */
1578	if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1579		tape->write_prot = 1;
1580	else
1581		tape->write_prot = tape->drv_write_prot;
1582
1583	/* Make sure drive isn't write protected if user wants to write. */
1584	if (tape->write_prot) {
1585		if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1586		    (filp->f_flags & O_ACCMODE) == O_RDWR) {
1587			clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1588			retval = -EROFS;
1589			goto out_put_tape;
1590		}
1591	}
1592
1593	/* Lock the tape drive door so user can't eject. */
1594	if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1595		if (!ide_set_media_lock(drive, tape->disk, 1)) {
1596			if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1597				tape->door_locked = DOOR_LOCKED;
1598		}
1599	}
1600	unlock_kernel();
1601	return 0;
1602
1603out_put_tape:
1604	ide_tape_put(tape);
1605	unlock_kernel();
1606	return retval;
1607}
1608
1609static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1610{
1611	idetape_tape_t *tape = drive->driver_data;
1612
1613	ide_tape_flush_merge_buffer(drive);
1614	tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1615	if (tape->buf != NULL) {
1616		idetape_pad_zeros(drive, tape->blk_size *
1617				(tape->user_bs_factor - 1));
1618		kfree(tape->buf);
1619		tape->buf = NULL;
1620	}
1621	idetape_write_filemark(drive);
1622	idetape_flush_tape_buffers(drive);
1623	idetape_flush_tape_buffers(drive);
1624}
1625
1626static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1627{
1628	struct ide_tape_obj *tape = filp->private_data;
1629	ide_drive_t *drive = tape->drive;
1630	unsigned int minor = iminor(inode);
1631
1632	lock_kernel();
1633	tape = drive->driver_data;
1634
1635	debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1636
1637	if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1638		idetape_write_release(drive, minor);
1639	if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1640		if (minor < 128)
1641			ide_tape_discard_merge_buffer(drive, 1);
1642	}
1643
1644	if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags))
1645		(void) idetape_rewind_tape(drive);
1646	if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1647		if (tape->door_locked == DOOR_LOCKED) {
1648			if (!ide_set_media_lock(drive, tape->disk, 0))
1649				tape->door_locked = DOOR_UNLOCKED;
1650		}
1651	}
1652	clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1653	ide_tape_put(tape);
1654	unlock_kernel();
1655	return 0;
1656}
1657
1658static void idetape_get_inquiry_results(ide_drive_t *drive)
1659{
1660	idetape_tape_t *tape = drive->driver_data;
1661	struct ide_atapi_pc pc;
1662	u8 pc_buf[256];
1663	char fw_rev[4], vendor_id[8], product_id[16];
1664
1665	idetape_create_inquiry_cmd(&pc);
1666	pc.buf = &pc_buf[0];
1667	pc.buf_size = sizeof(pc_buf);
1668
1669	if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1670		printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1671				tape->name);
1672		return;
1673	}
1674	memcpy(vendor_id, &pc.buf[8], 8);
1675	memcpy(product_id, &pc.buf[16], 16);
1676	memcpy(fw_rev, &pc.buf[32], 4);
1677
1678	ide_fixstring(vendor_id, 8, 0);
1679	ide_fixstring(product_id, 16, 0);
1680	ide_fixstring(fw_rev, 4, 0);
1681
1682	printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1683			drive->name, tape->name, vendor_id, product_id, fw_rev);
1684}
1685
1686/*
1687 * Ask the tape about its various parameters. In particular, we will adjust our
1688 * data transfer buffer	size to the recommended value as returned by the tape.
1689 */
1690static void idetape_get_mode_sense_results(ide_drive_t *drive)
1691{
1692	idetape_tape_t *tape = drive->driver_data;
1693	struct ide_atapi_pc pc;
1694	u8 *caps;
1695	u8 speed, max_speed;
1696
1697	idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1698	if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1699		printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1700				" some default values\n");
1701		tape->blk_size = 512;
1702		put_unaligned(52,   (u16 *)&tape->caps[12]);
1703		put_unaligned(540,  (u16 *)&tape->caps[14]);
1704		put_unaligned(6*52, (u16 *)&tape->caps[16]);
1705		return;
1706	}
1707	caps = pc.buf + 4 + pc.buf[3];
1708
1709	/* convert to host order and save for later use */
1710	speed = be16_to_cpup((__be16 *)&caps[14]);
1711	max_speed = be16_to_cpup((__be16 *)&caps[8]);
1712
1713	*(u16 *)&caps[8] = max_speed;
1714	*(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1715	*(u16 *)&caps[14] = speed;
1716	*(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1717
1718	if (!speed) {
1719		printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1720				"(assuming 650KB/sec)\n", drive->name);
1721		*(u16 *)&caps[14] = 650;
1722	}
1723	if (!max_speed) {
1724		printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1725				"(assuming 650KB/sec)\n", drive->name);
1726		*(u16 *)&caps[8] = 650;
1727	}
1728
1729	memcpy(&tape->caps, caps, 20);
1730
1731	/* device lacks locking support according to capabilities page */
1732	if ((caps[6] & 1) == 0)
1733		drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1734
1735	if (caps[7] & 0x02)
1736		tape->blk_size = 512;
1737	else if (caps[7] & 0x04)
1738		tape->blk_size = 1024;
1739}
1740
1741#ifdef CONFIG_IDE_PROC_FS
1742#define ide_tape_devset_get(name, field) \
1743static int get_##name(ide_drive_t *drive) \
1744{ \
1745	idetape_tape_t *tape = drive->driver_data; \
1746	return tape->field; \
1747}
1748
1749#define ide_tape_devset_set(name, field) \
1750static int set_##name(ide_drive_t *drive, int arg) \
1751{ \
1752	idetape_tape_t *tape = drive->driver_data; \
1753	tape->field = arg; \
1754	return 0; \
1755}
1756
1757#define ide_tape_devset_rw_field(_name, _field) \
1758ide_tape_devset_get(_name, _field) \
1759ide_tape_devset_set(_name, _field) \
1760IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1761
1762#define ide_tape_devset_r_field(_name, _field) \
1763ide_tape_devset_get(_name, _field) \
1764IDE_DEVSET(_name, 0, get_##_name, NULL)
1765
1766static int mulf_tdsc(ide_drive_t *drive)	{ return 1000; }
1767static int divf_tdsc(ide_drive_t *drive)	{ return   HZ; }
1768static int divf_buffer(ide_drive_t *drive)	{ return    2; }
1769static int divf_buffer_size(ide_drive_t *drive)	{ return 1024; }
1770
1771ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1772
1773ide_tape_devset_rw_field(debug_mask, debug_mask);
1774ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1775
1776ide_tape_devset_r_field(avg_speed, avg_speed);
1777ide_tape_devset_r_field(speed, caps[14]);
1778ide_tape_devset_r_field(buffer, caps[16]);
1779ide_tape_devset_r_field(buffer_size, buffer_size);
1780
1781static const struct ide_proc_devset idetape_settings[] = {
1782	__IDE_PROC_DEVSET(avg_speed,	0, 0xffff, NULL, NULL),
1783	__IDE_PROC_DEVSET(buffer,	0, 0xffff, NULL, divf_buffer),
1784	__IDE_PROC_DEVSET(buffer_size,	0, 0xffff, NULL, divf_buffer_size),
1785	__IDE_PROC_DEVSET(debug_mask,	0, 0xffff, NULL, NULL),
1786	__IDE_PROC_DEVSET(dsc_overlap,	0,      1, NULL, NULL),
1787	__IDE_PROC_DEVSET(speed,	0, 0xffff, NULL, NULL),
1788	__IDE_PROC_DEVSET(tdsc,		IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1789					mulf_tdsc, divf_tdsc),
1790	{ NULL },
1791};
1792#endif
1793
1794/*
1795 * The function below is called to:
1796 *
1797 * 1. Initialize our various state variables.
1798 * 2. Ask the tape for its capabilities.
1799 * 3. Allocate a buffer which will be used for data transfer. The buffer size
1800 * is chosen based on the recommendation which we received in step 2.
1801 *
1802 * Note that at this point ide.c already assigned us an irq, so that we can
1803 * queue requests here and wait for their completion.
1804 */
1805static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1806{
1807	unsigned long t;
1808	int speed;
1809	int buffer_size;
1810	u16 *ctl = (u16 *)&tape->caps[12];
1811
1812	drive->pc_callback	 = ide_tape_callback;
1813
1814	drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1815
1816	if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1817		printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1818				 tape->name);
1819		drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1820	}
1821
1822	/* Seagate Travan drives do not support DSC overlap. */
1823	if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1824		drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1825
1826	tape->minor = minor;
1827	tape->name[0] = 'h';
1828	tape->name[1] = 't';
1829	tape->name[2] = '0' + minor;
1830	tape->chrdev_dir = IDETAPE_DIR_NONE;
1831
1832	idetape_get_inquiry_results(drive);
1833	idetape_get_mode_sense_results(drive);
1834	ide_tape_get_bsize_from_bdesc(drive);
1835	tape->user_bs_factor = 1;
1836	tape->buffer_size = *ctl * tape->blk_size;
1837	while (tape->buffer_size > 0xffff) {
1838		printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1839		*ctl /= 2;
1840		tape->buffer_size = *ctl * tape->blk_size;
1841	}
1842	buffer_size = tape->buffer_size;
1843
1844	/* select the "best" DSC read/write polling freq */
1845	speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1846
1847	t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1848
1849	/*
1850	 * Ensure that the number we got makes sense; limit it within
1851	 * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1852	 */
1853	tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1854					 IDETAPE_DSC_RW_MAX);
1855	printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1856		"%lums tDSC%s\n",
1857		drive->name, tape->name, *(u16 *)&tape->caps[14],
1858		(*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1859		tape->buffer_size / 1024,
1860		tape->best_dsc_rw_freq * 1000 / HZ,
1861		(drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1862
1863	ide_proc_register_driver(drive, tape->driver);
1864}
1865
1866static void ide_tape_remove(ide_drive_t *drive)
1867{
1868	idetape_tape_t *tape = drive->driver_data;
1869
1870	ide_proc_unregister_driver(drive, tape->driver);
1871	device_del(&tape->dev);
1872	ide_unregister_region(tape->disk);
1873
1874	mutex_lock(&idetape_ref_mutex);
1875	put_device(&tape->dev);
1876	mutex_unlock(&idetape_ref_mutex);
1877}
1878
1879static void ide_tape_release(struct device *dev)
1880{
1881	struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1882	ide_drive_t *drive = tape->drive;
1883	struct gendisk *g = tape->disk;
1884
1885	BUG_ON(tape->valid);
1886
1887	drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1888	drive->driver_data = NULL;
1889	device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1890	device_destroy(idetape_sysfs_class,
1891			MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1892	idetape_devs[tape->minor] = NULL;
1893	g->private_data = NULL;
1894	put_disk(g);
1895	kfree(tape);
1896}
1897
1898#ifdef CONFIG_IDE_PROC_FS
1899static int proc_idetape_read_name
1900	(char *page, char **start, off_t off, int count, int *eof, void *data)
1901{
1902	ide_drive_t	*drive = (ide_drive_t *) data;
1903	idetape_tape_t	*tape = drive->driver_data;
1904	char		*out = page;
1905	int		len;
1906
1907	len = sprintf(out, "%s\n", tape->name);
1908	PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
1909}
1910
1911static ide_proc_entry_t idetape_proc[] = {
1912	{ "capacity",	S_IFREG|S_IRUGO,	proc_ide_read_capacity, NULL },
1913	{ "name",	S_IFREG|S_IRUGO,	proc_idetape_read_name,	NULL },
1914	{ NULL, 0, NULL, NULL }
1915};
1916
1917static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1918{
1919	return idetape_proc;
1920}
1921
1922static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1923{
1924	return idetape_settings;
1925}
1926#endif
1927
1928static int ide_tape_probe(ide_drive_t *);
1929
1930static struct ide_driver idetape_driver = {
1931	.gen_driver = {
1932		.owner		= THIS_MODULE,
1933		.name		= "ide-tape",
1934		.bus		= &ide_bus_type,
1935	},
1936	.probe			= ide_tape_probe,
1937	.remove			= ide_tape_remove,
1938	.version		= IDETAPE_VERSION,
1939	.do_request		= idetape_do_request,
1940#ifdef CONFIG_IDE_PROC_FS
1941	.proc_entries		= ide_tape_proc_entries,
1942	.proc_devsets		= ide_tape_proc_devsets,
1943#endif
1944};
1945
1946/* Our character device supporting functions, passed to register_chrdev. */
1947static const struct file_operations idetape_fops = {
1948	.owner		= THIS_MODULE,
1949	.read		= idetape_chrdev_read,
1950	.write		= idetape_chrdev_write,
1951	.ioctl		= idetape_chrdev_ioctl,
1952	.open		= idetape_chrdev_open,
1953	.release	= idetape_chrdev_release,
1954};
1955
1956static int idetape_open(struct block_device *bdev, fmode_t mode)
1957{
1958	struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk);
1959
1960	if (!tape)
1961		return -ENXIO;
1962
1963	return 0;
1964}
1965
1966static int idetape_release(struct gendisk *disk, fmode_t mode)
1967{
1968	struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1969
1970	ide_tape_put(tape);
1971	return 0;
1972}
1973
1974static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1975			unsigned int cmd, unsigned long arg)
1976{
1977	struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1978	ide_drive_t *drive = tape->drive;
1979	int err = generic_ide_ioctl(drive, bdev, cmd, arg);
1980	if (err == -EINVAL)
1981		err = idetape_blkdev_ioctl(drive, cmd, arg);
1982	return err;
1983}
1984
1985static struct block_device_operations idetape_block_ops = {
1986	.owner		= THIS_MODULE,
1987	.open		= idetape_open,
1988	.release	= idetape_release,
1989	.locked_ioctl	= idetape_ioctl,
1990};
1991
1992static int ide_tape_probe(ide_drive_t *drive)
1993{
1994	idetape_tape_t *tape;
1995	struct gendisk *g;
1996	int minor;
1997
1998	if (!strstr("ide-tape", drive->driver_req))
1999		goto failed;
2000
2001	if (drive->media != ide_tape)
2002		goto failed;
2003
2004	if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
2005	    ide_check_atapi_device(drive, DRV_NAME) == 0) {
2006		printk(KERN_ERR "ide-tape: %s: not supported by this version of"
2007				" the driver\n", drive->name);
2008		goto failed;
2009	}
2010	tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
2011	if (tape == NULL) {
2012		printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
2013				drive->name);
2014		goto failed;
2015	}
2016
2017	g = alloc_disk(1 << PARTN_BITS);
2018	if (!g)
2019		goto out_free_tape;
2020
2021	ide_init_disk(g, drive);
2022
2023	tape->dev.parent = &drive->gendev;
2024	tape->dev.release = ide_tape_release;
2025	dev_set_name(&tape->dev, dev_name(&drive->gendev));
2026
2027	if (device_register(&tape->dev))
2028		goto out_free_disk;
2029
2030	tape->drive = drive;
2031	tape->driver = &idetape_driver;
2032	tape->disk = g;
2033
2034	g->private_data = &tape->driver;
2035
2036	drive->driver_data = tape;
2037
2038	mutex_lock(&idetape_ref_mutex);
2039	for (minor = 0; idetape_devs[minor]; minor++)
2040		;
2041	idetape_devs[minor] = tape;
2042	mutex_unlock(&idetape_ref_mutex);
2043
2044	idetape_setup(drive, tape, minor);
2045
2046	device_create(idetape_sysfs_class, &drive->gendev,
2047		      MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2048	device_create(idetape_sysfs_class, &drive->gendev,
2049		      MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2050		      "n%s", tape->name);
2051
2052	g->fops = &idetape_block_ops;
2053	ide_register_region(g);
2054
2055	return 0;
2056
2057out_free_disk:
2058	put_disk(g);
2059out_free_tape:
2060	kfree(tape);
2061failed:
2062	return -ENODEV;
2063}
2064
2065static void __exit idetape_exit(void)
2066{
2067	driver_unregister(&idetape_driver.gen_driver);
2068	class_destroy(idetape_sysfs_class);
2069	unregister_chrdev(IDETAPE_MAJOR, "ht");
2070}
2071
2072static int __init idetape_init(void)
2073{
2074	int error = 1;
2075	idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2076	if (IS_ERR(idetape_sysfs_class)) {
2077		idetape_sysfs_class = NULL;
2078		printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2079		error = -EBUSY;
2080		goto out;
2081	}
2082
2083	if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2084		printk(KERN_ERR "ide-tape: Failed to register chrdev"
2085				" interface\n");
2086		error = -EBUSY;
2087		goto out_free_class;
2088	}
2089
2090	error = driver_register(&idetape_driver.gen_driver);
2091	if (error)
2092		goto out_free_driver;
2093
2094	return 0;
2095
2096out_free_driver:
2097	driver_unregister(&idetape_driver.gen_driver);
2098out_free_class:
2099	class_destroy(idetape_sysfs_class);
2100out:
2101	return error;
2102}
2103
2104MODULE_ALIAS("ide:*m-tape*");
2105module_init(idetape_init);
2106module_exit(idetape_exit);
2107MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2108MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2109MODULE_LICENSE("GPL");
2110