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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/seq_file.h>
35#include <linux/slab.h>
36#include <linux/pci.h>
37#include <linux/ide.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/uaccess.h>
45#include <linux/io.h>
46#include <asm/unaligned.h>
47#include <linux/mtio.h>
48
49/* define to see debug info */
50#undef IDETAPE_DEBUG_LOG
51
52#ifdef IDETAPE_DEBUG_LOG
53#define ide_debug_log(lvl, fmt, args...) __ide_debug_log(lvl, fmt, ## args)
54#else
55#define ide_debug_log(lvl, fmt, args...) do {} while (0)
56#endif
57
58/**************************** Tunable parameters *****************************/
59/*
60 * After each failed packet command we issue a request sense command and retry
61 * the packet command IDETAPE_MAX_PC_RETRIES times.
62 *
63 * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
64 */
65#define IDETAPE_MAX_PC_RETRIES		3
66
67/*
68 * The following parameter is used to select the point in the internal tape fifo
69 * in which we will start to refill the buffer. Decreasing the following
70 * parameter will improve the system's latency and interactive response, while
71 * using a high value might improve system throughput.
72 */
73#define IDETAPE_FIFO_THRESHOLD		2
74
75/*
76 * DSC polling parameters.
77 *
78 * Polling for DSC (a single bit in the status register) is a very important
79 * function in ide-tape. There are two cases in which we poll for DSC:
80 *
81 * 1. Before a read/write packet command, to ensure that we can transfer data
82 * from/to the tape's data buffers, without causing an actual media access.
83 * In case the tape is not ready yet, we take out our request from the device
84 * request queue, so that ide.c could service requests from the other device
85 * on the same interface in the meantime.
86 *
87 * 2. After the successful initialization of a "media access packet command",
88 * which is a command that can take a long time to complete (the interval can
89 * range from several seconds to even an hour). Again, we postpone our request
90 * in the middle to free the bus for the other device. The polling frequency
91 * here should be lower than the read/write frequency since those media access
92 * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
93 * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
94 * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
95 *
96 * We also set a timeout for the timer, in case something goes wrong. The
97 * timeout should be longer then the maximum execution time of a tape operation.
98 */
99
100/* DSC timings. */
101#define IDETAPE_DSC_RW_MIN		5*HZ/100	/* 50 msec */
102#define IDETAPE_DSC_RW_MAX		40*HZ/100	/* 400 msec */
103#define IDETAPE_DSC_RW_TIMEOUT		2*60*HZ		/* 2 minutes */
104#define IDETAPE_DSC_MA_FAST		2*HZ		/* 2 seconds */
105#define IDETAPE_DSC_MA_THRESHOLD	5*60*HZ		/* 5 minutes */
106#define IDETAPE_DSC_MA_SLOW		30*HZ		/* 30 seconds */
107#define IDETAPE_DSC_MA_TIMEOUT		2*60*60*HZ	/* 2 hours */
108
109/*************************** End of tunable parameters ***********************/
110
111/* tape directions */
112enum {
113	IDETAPE_DIR_NONE  = (1 << 0),
114	IDETAPE_DIR_READ  = (1 << 1),
115	IDETAPE_DIR_WRITE = (1 << 2),
116};
117
118/* Tape door status */
119#define DOOR_UNLOCKED			0
120#define DOOR_LOCKED			1
121#define DOOR_EXPLICITLY_LOCKED		2
122
123/* Some defines for the SPACE command */
124#define IDETAPE_SPACE_OVER_FILEMARK	1
125#define IDETAPE_SPACE_TO_EOD		3
126
127/* Some defines for the LOAD UNLOAD command */
128#define IDETAPE_LU_LOAD_MASK		1
129#define IDETAPE_LU_RETENSION_MASK	2
130#define IDETAPE_LU_EOT_MASK		4
131
132/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
133#define IDETAPE_BLOCK_DESCRIPTOR	0
134#define IDETAPE_CAPABILITIES_PAGE	0x2a
135
136/*
137 * Most of our global data which we need to save even as we leave the driver due
138 * to an interrupt or a timer event is stored in the struct defined below.
139 */
140typedef struct ide_tape_obj {
141	ide_drive_t		*drive;
142	struct ide_driver	*driver;
143	struct gendisk		*disk;
144	struct device		dev;
145
146	/* used by REQ_IDETAPE_{READ,WRITE} requests */
147	struct ide_atapi_pc queued_pc;
148
149	/*
150	 * DSC polling variables.
151	 *
152	 * While polling for DSC we use postponed_rq to postpone the current
153	 * request so that ide.c will be able to service pending requests on the
154	 * other device. Note that at most we will have only one DSC (usually
155	 * data transfer) request in the device request queue.
156	 */
157	bool postponed_rq;
158
159	/* The time in which we started polling for DSC */
160	unsigned long dsc_polling_start;
161	/* Timer used to poll for dsc */
162	struct timer_list dsc_timer;
163	/* Read/Write dsc polling frequency */
164	unsigned long best_dsc_rw_freq;
165	unsigned long dsc_poll_freq;
166	unsigned long dsc_timeout;
167
168	/* Read position information */
169	u8 partition;
170	/* Current block */
171	unsigned int first_frame;
172
173	/* Last error information */
174	u8 sense_key, asc, ascq;
175
176	/* Character device operation */
177	unsigned int minor;
178	/* device name */
179	char name[4];
180	/* Current character device data transfer direction */
181	u8 chrdev_dir;
182
183	/* tape block size, usually 512 or 1024 bytes */
184	unsigned short blk_size;
185	int user_bs_factor;
186
187	/* Copy of the tape's Capabilities and Mechanical Page */
188	u8 caps[20];
189
190	/*
191	 * Active data transfer request parameters.
192	 *
193	 * At most, there is only one ide-tape originated data transfer request
194	 * in the device request queue. This allows ide.c to easily service
195	 * requests from the other device when we postpone our active request.
196	 */
197
198	/* Data buffer size chosen based on the tape's recommendation */
199	int buffer_size;
200	/* Staging buffer of buffer_size bytes */
201	void *buf;
202	/* The read/write cursor */
203	void *cur;
204	/* The number of valid bytes in buf */
205	size_t valid;
206
207	/* Measures average tape speed */
208	unsigned long avg_time;
209	int avg_size;
210	int avg_speed;
211
212	/* the door is currently locked */
213	int door_locked;
214	/* the tape hardware is write protected */
215	char drv_write_prot;
216	/* the tape is write protected (hardware or opened as read-only) */
217	char write_prot;
218} idetape_tape_t;
219
220static DEFINE_MUTEX(ide_tape_mutex);
221static DEFINE_MUTEX(idetape_ref_mutex);
222
223static DEFINE_MUTEX(idetape_chrdev_mutex);
224
225static struct class *idetape_sysfs_class;
226
227static void ide_tape_release(struct device *);
228
229static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
230
231static struct ide_tape_obj *ide_tape_get(struct gendisk *disk, bool cdev,
232					 unsigned int i)
233{
234	struct ide_tape_obj *tape = NULL;
235
236	mutex_lock(&idetape_ref_mutex);
237
238	if (cdev)
239		tape = idetape_devs[i];
240	else
241		tape = ide_drv_g(disk, ide_tape_obj);
242
243	if (tape) {
244		if (ide_device_get(tape->drive))
245			tape = NULL;
246		else
247			get_device(&tape->dev);
248	}
249
250	mutex_unlock(&idetape_ref_mutex);
251	return tape;
252}
253
254static void ide_tape_put(struct ide_tape_obj *tape)
255{
256	ide_drive_t *drive = tape->drive;
257
258	mutex_lock(&idetape_ref_mutex);
259	put_device(&tape->dev);
260	ide_device_put(drive);
261	mutex_unlock(&idetape_ref_mutex);
262}
263
264/*
265 * called on each failed packet command retry to analyze the request sense. We
266 * currently do not utilize this information.
267 */
268static void idetape_analyze_error(ide_drive_t *drive)
269{
270	idetape_tape_t *tape = drive->driver_data;
271	struct ide_atapi_pc *pc = drive->failed_pc;
272	struct request *rq = drive->hwif->rq;
273	u8 *sense = bio_data(rq->bio);
274
275	tape->sense_key = sense[2] & 0xF;
276	tape->asc       = sense[12];
277	tape->ascq      = sense[13];
278
279	ide_debug_log(IDE_DBG_FUNC,
280		      "cmd: 0x%x, sense key = %x, asc = %x, ascq = %x",
281		      rq->cmd[0], tape->sense_key, tape->asc, tape->ascq);
282
283	/* correct remaining bytes to transfer */
284	if (pc->flags & PC_FLAG_DMA_ERROR)
285		rq->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
286
287	/*
288	 * If error was the result of a zero-length read or write command,
289	 * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
290	 * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
291	 */
292	if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
293	    /* length == 0 */
294	    && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
295		if (tape->sense_key == 5) {
296			/* don't report an error, everything's ok */
297			pc->error = 0;
298			/* don't retry read/write */
299			pc->flags |= PC_FLAG_ABORT;
300		}
301	}
302	if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
303		pc->error = IDE_DRV_ERROR_FILEMARK;
304		pc->flags |= PC_FLAG_ABORT;
305	}
306	if (pc->c[0] == WRITE_6) {
307		if ((sense[2] & 0x40) || (tape->sense_key == 0xd
308		     && tape->asc == 0x0 && tape->ascq == 0x2)) {
309			pc->error = IDE_DRV_ERROR_EOD;
310			pc->flags |= PC_FLAG_ABORT;
311		}
312	}
313	if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
314		if (tape->sense_key == 8) {
315			pc->error = IDE_DRV_ERROR_EOD;
316			pc->flags |= PC_FLAG_ABORT;
317		}
318		if (!(pc->flags & PC_FLAG_ABORT) &&
319		    (blk_rq_bytes(rq) - rq->resid_len))
320			pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
321	}
322}
323
324static void ide_tape_handle_dsc(ide_drive_t *);
325
326static int ide_tape_callback(ide_drive_t *drive, int dsc)
327{
328	idetape_tape_t *tape = drive->driver_data;
329	struct ide_atapi_pc *pc = drive->pc;
330	struct request *rq = drive->hwif->rq;
331	int uptodate = pc->error ? 0 : 1;
332	int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
333
334	ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc: %d, err: %d", rq->cmd[0],
335		      dsc, err);
336
337	if (dsc)
338		ide_tape_handle_dsc(drive);
339
340	if (drive->failed_pc == pc)
341		drive->failed_pc = NULL;
342
343	if (pc->c[0] == REQUEST_SENSE) {
344		if (uptodate)
345			idetape_analyze_error(drive);
346		else
347			printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
348					"itself - Aborting request!\n");
349	} else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
350		unsigned int blocks =
351			(blk_rq_bytes(rq) - rq->resid_len) / tape->blk_size;
352
353		tape->avg_size += blocks * tape->blk_size;
354
355		if (time_after_eq(jiffies, tape->avg_time + HZ)) {
356			tape->avg_speed = tape->avg_size * HZ /
357				(jiffies - tape->avg_time) / 1024;
358			tape->avg_size = 0;
359			tape->avg_time = jiffies;
360		}
361
362		tape->first_frame += blocks;
363
364		if (pc->error) {
365			uptodate = 0;
366			err = pc->error;
367		}
368	}
369	rq->errors = err;
370
371	return uptodate;
372}
373
374/*
375 * Postpone the current request so that ide.c will be able to service requests
376 * from another device on the same port while we are polling for DSC.
377 */
378static void ide_tape_stall_queue(ide_drive_t *drive)
379{
380	idetape_tape_t *tape = drive->driver_data;
381
382	ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc_poll_freq: %lu",
383		      drive->hwif->rq->cmd[0], tape->dsc_poll_freq);
384
385	tape->postponed_rq = true;
386
387	ide_stall_queue(drive, tape->dsc_poll_freq);
388}
389
390static void ide_tape_handle_dsc(ide_drive_t *drive)
391{
392	idetape_tape_t *tape = drive->driver_data;
393
394	/* Media access command */
395	tape->dsc_polling_start = jiffies;
396	tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
397	tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
398	/* Allow ide.c to handle other requests */
399	ide_tape_stall_queue(drive);
400}
401
402/*
403 * Packet Command Interface
404 *
405 * The current Packet Command is available in drive->pc, and will not change
406 * until we finish handling it. Each packet command is associated with a
407 * callback function that will be called when the command is finished.
408 *
409 * The handling will be done in three stages:
410 *
411 * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
412 * the interrupt handler to ide_pc_intr.
413 *
414 * 2. On each interrupt, ide_pc_intr will be called. This step will be
415 * repeated until the device signals us that no more interrupts will be issued.
416 *
417 * 3. ATAPI Tape media access commands have immediate status with a delayed
418 * process. In case of a successful initiation of a media access packet command,
419 * the DSC bit will be set when the actual execution of the command is finished.
420 * Since the tape drive will not issue an interrupt, we have to poll for this
421 * event. In this case, we define the request as "low priority request" by
422 * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
423 * exit the driver.
424 *
425 * ide.c will then give higher priority to requests which originate from the
426 * other device, until will change rq_status to RQ_ACTIVE.
427 *
428 * 4. When the packet command is finished, it will be checked for errors.
429 *
430 * 5. In case an error was found, we queue a request sense packet command in
431 * front of the request queue and retry the operation up to
432 * IDETAPE_MAX_PC_RETRIES times.
433 *
434 * 6. In case no error was found, or we decided to give up and not to retry
435 * again, the callback function will be called and then we will handle the next
436 * request.
437 */
438
439static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
440					 struct ide_cmd *cmd,
441					 struct ide_atapi_pc *pc)
442{
443	idetape_tape_t *tape = drive->driver_data;
444	struct request *rq = drive->hwif->rq;
445
446	if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
447		drive->failed_pc = pc;
448
449	/* Set the current packet command */
450	drive->pc = pc;
451
452	if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
453		(pc->flags & PC_FLAG_ABORT)) {
454
455		/*
456		 * We will "abort" retrying a packet command in case legitimate
457		 * error code was received (crossing a filemark, or end of the
458		 * media, for example).
459		 */
460		if (!(pc->flags & PC_FLAG_ABORT)) {
461			if (!(pc->c[0] == TEST_UNIT_READY &&
462			      tape->sense_key == 2 && tape->asc == 4 &&
463			     (tape->ascq == 1 || tape->ascq == 8))) {
464				printk(KERN_ERR "ide-tape: %s: I/O error, "
465						"pc = %2x, key = %2x, "
466						"asc = %2x, ascq = %2x\n",
467						tape->name, pc->c[0],
468						tape->sense_key, tape->asc,
469						tape->ascq);
470			}
471			/* Giving up */
472			pc->error = IDE_DRV_ERROR_GENERAL;
473		}
474
475		drive->failed_pc = NULL;
476		drive->pc_callback(drive, 0);
477		ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
478		return ide_stopped;
479	}
480	ide_debug_log(IDE_DBG_SENSE, "retry #%d, cmd: 0x%02x", pc->retries,
481		      pc->c[0]);
482
483	pc->retries++;
484
485	return ide_issue_pc(drive, cmd);
486}
487
488/* A mode sense command is used to "sense" tape parameters. */
489static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
490{
491	ide_init_pc(pc);
492	pc->c[0] = MODE_SENSE;
493	if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
494		/* DBD = 1 - Don't return block descriptors */
495		pc->c[1] = 8;
496	pc->c[2] = page_code;
497	/*
498	 * Changed pc->c[3] to 0 (255 will at best return unused info).
499	 *
500	 * For SCSI this byte is defined as subpage instead of high byte
501	 * of length and some IDE drives seem to interpret it this way
502	 * and return an error when 255 is used.
503	 */
504	pc->c[3] = 0;
505	/* We will just discard data in that case */
506	pc->c[4] = 255;
507	if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
508		pc->req_xfer = 12;
509	else if (page_code == IDETAPE_CAPABILITIES_PAGE)
510		pc->req_xfer = 24;
511	else
512		pc->req_xfer = 50;
513}
514
515static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
516{
517	ide_hwif_t *hwif = drive->hwif;
518	idetape_tape_t *tape = drive->driver_data;
519	struct ide_atapi_pc *pc = drive->pc;
520	u8 stat;
521
522	stat = hwif->tp_ops->read_status(hwif);
523
524	if (stat & ATA_DSC) {
525		if (stat & ATA_ERR) {
526			/* Error detected */
527			if (pc->c[0] != TEST_UNIT_READY)
528				printk(KERN_ERR "ide-tape: %s: I/O error, ",
529						tape->name);
530			/* Retry operation */
531			ide_retry_pc(drive);
532			return ide_stopped;
533		}
534		pc->error = 0;
535	} else {
536		pc->error = IDE_DRV_ERROR_GENERAL;
537		drive->failed_pc = NULL;
538	}
539	drive->pc_callback(drive, 0);
540	return ide_stopped;
541}
542
543static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
544				   struct ide_atapi_pc *pc, struct request *rq,
545				   u8 opcode)
546{
547	unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
548
549	ide_init_pc(pc);
550	put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
551	pc->c[1] = 1;
552
553	if (blk_rq_bytes(rq) == tape->buffer_size)
554		pc->flags |= PC_FLAG_DMA_OK;
555
556	if (opcode == READ_6)
557		pc->c[0] = READ_6;
558	else if (opcode == WRITE_6) {
559		pc->c[0] = WRITE_6;
560		pc->flags |= PC_FLAG_WRITING;
561	}
562
563	memcpy(rq->cmd, pc->c, 12);
564}
565
566static ide_startstop_t idetape_do_request(ide_drive_t *drive,
567					  struct request *rq, sector_t block)
568{
569	ide_hwif_t *hwif = drive->hwif;
570	idetape_tape_t *tape = drive->driver_data;
571	struct ide_atapi_pc *pc = NULL;
572	struct ide_cmd cmd;
573	u8 stat;
574
575	ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, sector: %llu, nr_sectors: %u",
576		      rq->cmd[0], (unsigned long long)blk_rq_pos(rq),
577		      blk_rq_sectors(rq));
578
579	BUG_ON(!(rq->cmd_type == REQ_TYPE_SPECIAL ||
580		 rq->cmd_type == REQ_TYPE_SENSE));
581
582	/* Retry a failed packet command */
583	if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
584		pc = drive->failed_pc;
585		goto out;
586	}
587
588	/*
589	 * If the tape is still busy, postpone our request and service
590	 * the other device meanwhile.
591	 */
592	stat = hwif->tp_ops->read_status(hwif);
593
594	if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
595	    (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
596		drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
597
598	if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
599		drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
600		drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
601	}
602
603	if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
604	    !(stat & ATA_DSC)) {
605		if (!tape->postponed_rq) {
606			tape->dsc_polling_start = jiffies;
607			tape->dsc_poll_freq = tape->best_dsc_rw_freq;
608			tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
609		} else if (time_after(jiffies, tape->dsc_timeout)) {
610			printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
611				tape->name);
612			if (rq->cmd[13] & REQ_IDETAPE_PC2) {
613				idetape_media_access_finished(drive);
614				return ide_stopped;
615			} else {
616				return ide_do_reset(drive);
617			}
618		} else if (time_after(jiffies,
619					tape->dsc_polling_start +
620					IDETAPE_DSC_MA_THRESHOLD))
621			tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
622		ide_tape_stall_queue(drive);
623		return ide_stopped;
624	} else {
625		drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
626		tape->postponed_rq = false;
627	}
628
629	if (rq->cmd[13] & REQ_IDETAPE_READ) {
630		pc = &tape->queued_pc;
631		ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
632		goto out;
633	}
634	if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
635		pc = &tape->queued_pc;
636		ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
637		goto out;
638	}
639	if (rq->cmd[13] & REQ_IDETAPE_PC1) {
640		pc = (struct ide_atapi_pc *)rq->special;
641		rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
642		rq->cmd[13] |= REQ_IDETAPE_PC2;
643		goto out;
644	}
645	if (rq->cmd[13] & REQ_IDETAPE_PC2) {
646		idetape_media_access_finished(drive);
647		return ide_stopped;
648	}
649	BUG();
650
651out:
652	/* prepare sense request for this command */
653	ide_prep_sense(drive, rq);
654
655	memset(&cmd, 0, sizeof(cmd));
656
657	if (rq_data_dir(rq))
658		cmd.tf_flags |= IDE_TFLAG_WRITE;
659
660	cmd.rq = rq;
661
662	ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
663	ide_map_sg(drive, &cmd);
664
665	return ide_tape_issue_pc(drive, &cmd, pc);
666}
667
668/*
669 * Write a filemark if write_filemark=1. Flush the device buffers without
670 * writing a filemark otherwise.
671 */
672static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
673		struct ide_atapi_pc *pc, int write_filemark)
674{
675	ide_init_pc(pc);
676	pc->c[0] = WRITE_FILEMARKS;
677	pc->c[4] = write_filemark;
678	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
679}
680
681static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
682{
683	idetape_tape_t *tape = drive->driver_data;
684	struct gendisk *disk = tape->disk;
685	int load_attempted = 0;
686
687	/* Wait for the tape to become ready */
688	set_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT), &drive->atapi_flags);
689	timeout += jiffies;
690	while (time_before(jiffies, timeout)) {
691		if (ide_do_test_unit_ready(drive, disk) == 0)
692			return 0;
693		if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
694		    || (tape->asc == 0x3A)) {
695			/* no media */
696			if (load_attempted)
697				return -ENOMEDIUM;
698			ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
699			load_attempted = 1;
700		/* not about to be ready */
701		} else if (!(tape->sense_key == 2 && tape->asc == 4 &&
702			     (tape->ascq == 1 || tape->ascq == 8)))
703			return -EIO;
704		msleep(100);
705	}
706	return -EIO;
707}
708
709static int idetape_flush_tape_buffers(ide_drive_t *drive)
710{
711	struct ide_tape_obj *tape = drive->driver_data;
712	struct ide_atapi_pc pc;
713	int rc;
714
715	idetape_create_write_filemark_cmd(drive, &pc, 0);
716	rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
717	if (rc)
718		return rc;
719	idetape_wait_ready(drive, 60 * 5 * HZ);
720	return 0;
721}
722
723static int ide_tape_read_position(ide_drive_t *drive)
724{
725	idetape_tape_t *tape = drive->driver_data;
726	struct ide_atapi_pc pc;
727	u8 buf[20];
728
729	ide_debug_log(IDE_DBG_FUNC, "enter");
730
731	/* prep cmd */
732	ide_init_pc(&pc);
733	pc.c[0] = READ_POSITION;
734	pc.req_xfer = 20;
735
736	if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
737		return -1;
738
739	if (!pc.error) {
740		ide_debug_log(IDE_DBG_FUNC, "BOP - %s",
741				(buf[0] & 0x80) ? "Yes" : "No");
742		ide_debug_log(IDE_DBG_FUNC, "EOP - %s",
743				(buf[0] & 0x40) ? "Yes" : "No");
744
745		if (buf[0] & 0x4) {
746			printk(KERN_INFO "ide-tape: Block location is unknown"
747					 "to the tape\n");
748			clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
749				  &drive->atapi_flags);
750			return -1;
751		} else {
752			ide_debug_log(IDE_DBG_FUNC, "Block Location: %u",
753				      be32_to_cpup((__be32 *)&buf[4]));
754
755			tape->partition = buf[1];
756			tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
757			set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
758				&drive->atapi_flags);
759		}
760	}
761
762	return tape->first_frame;
763}
764
765static void idetape_create_locate_cmd(ide_drive_t *drive,
766		struct ide_atapi_pc *pc,
767		unsigned int block, u8 partition, int skip)
768{
769	ide_init_pc(pc);
770	pc->c[0] = POSITION_TO_ELEMENT;
771	pc->c[1] = 2;
772	put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
773	pc->c[8] = partition;
774	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
775}
776
777static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
778{
779	idetape_tape_t *tape = drive->driver_data;
780
781	if (tape->chrdev_dir != IDETAPE_DIR_READ)
782		return;
783
784	clear_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
785	tape->valid = 0;
786	if (tape->buf != NULL) {
787		kfree(tape->buf);
788		tape->buf = NULL;
789	}
790
791	tape->chrdev_dir = IDETAPE_DIR_NONE;
792}
793
794/*
795 * Position the tape to the requested block using the LOCATE packet command.
796 * A READ POSITION command is then issued to check where we are positioned. Like
797 * all higher level operations, we queue the commands at the tail of the request
798 * queue and wait for their completion.
799 */
800static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
801		u8 partition, int skip)
802{
803	idetape_tape_t *tape = drive->driver_data;
804	struct gendisk *disk = tape->disk;
805	int ret;
806	struct ide_atapi_pc pc;
807
808	if (tape->chrdev_dir == IDETAPE_DIR_READ)
809		__ide_tape_discard_merge_buffer(drive);
810	idetape_wait_ready(drive, 60 * 5 * HZ);
811	idetape_create_locate_cmd(drive, &pc, block, partition, skip);
812	ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
813	if (ret)
814		return ret;
815
816	ret = ide_tape_read_position(drive);
817	if (ret < 0)
818		return ret;
819	return 0;
820}
821
822static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
823					  int restore_position)
824{
825	idetape_tape_t *tape = drive->driver_data;
826	int seek, position;
827
828	__ide_tape_discard_merge_buffer(drive);
829	if (restore_position) {
830		position = ide_tape_read_position(drive);
831		seek = position > 0 ? position : 0;
832		if (idetape_position_tape(drive, seek, 0, 0)) {
833			printk(KERN_INFO "ide-tape: %s: position_tape failed in"
834					 " %s\n", tape->name, __func__);
835			return;
836		}
837	}
838}
839
840/*
841 * Generate a read/write request for the block device interface and wait for it
842 * to be serviced.
843 */
844static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
845{
846	idetape_tape_t *tape = drive->driver_data;
847	struct request *rq;
848	int ret;
849
850	ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, size: %d", cmd, size);
851
852	BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
853	BUG_ON(size < 0 || size % tape->blk_size);
854
855	rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
856	rq->cmd_type = REQ_TYPE_SPECIAL;
857	rq->cmd[13] = cmd;
858	rq->rq_disk = tape->disk;
859	rq->__sector = tape->first_frame;
860
861	if (size) {
862		ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
863				      __GFP_WAIT);
864		if (ret)
865			goto out_put;
866	}
867
868	blk_execute_rq(drive->queue, tape->disk, rq, 0);
869
870	/* calculate the number of transferred bytes and update buffer state */
871	size -= rq->resid_len;
872	tape->cur = tape->buf;
873	if (cmd == REQ_IDETAPE_READ)
874		tape->valid = size;
875	else
876		tape->valid = 0;
877
878	ret = size;
879	if (rq->errors == IDE_DRV_ERROR_GENERAL)
880		ret = -EIO;
881out_put:
882	blk_put_request(rq);
883	return ret;
884}
885
886static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
887{
888	ide_init_pc(pc);
889	pc->c[0] = INQUIRY;
890	pc->c[4] = 254;
891	pc->req_xfer = 254;
892}
893
894static void idetape_create_rewind_cmd(ide_drive_t *drive,
895		struct ide_atapi_pc *pc)
896{
897	ide_init_pc(pc);
898	pc->c[0] = REZERO_UNIT;
899	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
900}
901
902static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
903{
904	ide_init_pc(pc);
905	pc->c[0] = ERASE;
906	pc->c[1] = 1;
907	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
908}
909
910static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
911{
912	ide_init_pc(pc);
913	pc->c[0] = SPACE;
914	put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
915	pc->c[1] = cmd;
916	pc->flags |= PC_FLAG_WAIT_FOR_DSC;
917}
918
919static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
920{
921	idetape_tape_t *tape = drive->driver_data;
922
923	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
924		printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
925				" but we are not writing.\n");
926		return;
927	}
928	if (tape->buf) {
929		size_t aligned = roundup(tape->valid, tape->blk_size);
930
931		memset(tape->cur, 0, aligned - tape->valid);
932		idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
933		kfree(tape->buf);
934		tape->buf = NULL;
935	}
936	tape->chrdev_dir = IDETAPE_DIR_NONE;
937}
938
939static int idetape_init_rw(ide_drive_t *drive, int dir)
940{
941	idetape_tape_t *tape = drive->driver_data;
942	int rc;
943
944	BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
945
946	if (tape->chrdev_dir == dir)
947		return 0;
948
949	if (tape->chrdev_dir == IDETAPE_DIR_READ)
950		ide_tape_discard_merge_buffer(drive, 1);
951	else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
952		ide_tape_flush_merge_buffer(drive);
953		idetape_flush_tape_buffers(drive);
954	}
955
956	if (tape->buf || tape->valid) {
957		printk(KERN_ERR "ide-tape: valid should be 0 now\n");
958		tape->valid = 0;
959	}
960
961	tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
962	if (!tape->buf)
963		return -ENOMEM;
964	tape->chrdev_dir = dir;
965	tape->cur = tape->buf;
966
967	/*
968	 * Issue a 0 rw command to ensure that DSC handshake is
969	 * switched from completion mode to buffer available mode.  No
970	 * point in issuing this if DSC overlap isn't supported, some
971	 * drives (Seagate STT3401A) will return an error.
972	 */
973	if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
974		int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
975						  : REQ_IDETAPE_WRITE;
976
977		rc = idetape_queue_rw_tail(drive, cmd, 0);
978		if (rc < 0) {
979			kfree(tape->buf);
980			tape->buf = NULL;
981			tape->chrdev_dir = IDETAPE_DIR_NONE;
982			return rc;
983		}
984	}
985
986	return 0;
987}
988
989static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
990{
991	idetape_tape_t *tape = drive->driver_data;
992
993	memset(tape->buf, 0, tape->buffer_size);
994
995	while (bcount) {
996		unsigned int count = min(tape->buffer_size, bcount);
997
998		idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
999		bcount -= count;
1000	}
1001}
1002
1003/*
1004 * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1005 * currently support only one partition.
1006 */
1007static int idetape_rewind_tape(ide_drive_t *drive)
1008{
1009	struct ide_tape_obj *tape = drive->driver_data;
1010	struct gendisk *disk = tape->disk;
1011	struct ide_atapi_pc pc;
1012	int ret;
1013
1014	ide_debug_log(IDE_DBG_FUNC, "enter");
1015
1016	idetape_create_rewind_cmd(drive, &pc);
1017	ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1018	if (ret)
1019		return ret;
1020
1021	ret = ide_tape_read_position(drive);
1022	if (ret < 0)
1023		return ret;
1024	return 0;
1025}
1026
1027/* mtio.h compatible commands should be issued to the chrdev interface. */
1028static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1029				unsigned long arg)
1030{
1031	idetape_tape_t *tape = drive->driver_data;
1032	void __user *argp = (void __user *)arg;
1033
1034	struct idetape_config {
1035		int dsc_rw_frequency;
1036		int dsc_media_access_frequency;
1037		int nr_stages;
1038	} config;
1039
1040	ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%04x", cmd);
1041
1042	switch (cmd) {
1043	case 0x0340:
1044		if (copy_from_user(&config, argp, sizeof(config)))
1045			return -EFAULT;
1046		tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1047		break;
1048	case 0x0350:
1049		memset(&config, 0, sizeof(config));
1050		config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1051		config.nr_stages = 1;
1052		if (copy_to_user(argp, &config, sizeof(config)))
1053			return -EFAULT;
1054		break;
1055	default:
1056		return -EIO;
1057	}
1058	return 0;
1059}
1060
1061static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1062					int mt_count)
1063{
1064	idetape_tape_t *tape = drive->driver_data;
1065	struct gendisk *disk = tape->disk;
1066	struct ide_atapi_pc pc;
1067	int retval, count = 0;
1068	int sprev = !!(tape->caps[4] & 0x20);
1069
1070
1071	ide_debug_log(IDE_DBG_FUNC, "mt_op: %d, mt_count: %d", mt_op, mt_count);
1072
1073	if (mt_count == 0)
1074		return 0;
1075	if (MTBSF == mt_op || MTBSFM == mt_op) {
1076		if (!sprev)
1077			return -EIO;
1078		mt_count = -mt_count;
1079	}
1080
1081	if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1082		tape->valid = 0;
1083		if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1084				       &drive->atapi_flags))
1085			++count;
1086		ide_tape_discard_merge_buffer(drive, 0);
1087	}
1088
1089	switch (mt_op) {
1090	case MTFSF:
1091	case MTBSF:
1092		idetape_create_space_cmd(&pc, mt_count - count,
1093					 IDETAPE_SPACE_OVER_FILEMARK);
1094		return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1095	case MTFSFM:
1096	case MTBSFM:
1097		if (!sprev)
1098			return -EIO;
1099		retval = idetape_space_over_filemarks(drive, MTFSF,
1100						      mt_count - count);
1101		if (retval)
1102			return retval;
1103		count = (MTBSFM == mt_op ? 1 : -1);
1104		return idetape_space_over_filemarks(drive, MTFSF, count);
1105	default:
1106		printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1107				mt_op);
1108		return -EIO;
1109	}
1110}
1111
1112/*
1113 * Our character device read / write functions.
1114 *
1115 * The tape is optimized to maximize throughput when it is transferring an
1116 * integral number of the "continuous transfer limit", which is a parameter of
1117 * the specific tape (26kB on my particular tape, 32kB for Onstream).
1118 *
1119 * As of version 1.3 of the driver, the character device provides an abstract
1120 * continuous view of the media - any mix of block sizes (even 1 byte) on the
1121 * same backup/restore procedure is supported. The driver will internally
1122 * convert the requests to the recommended transfer unit, so that an unmatch
1123 * between the user's block size to the recommended size will only result in a
1124 * (slightly) increased driver overhead, but will no longer hit performance.
1125 * This is not applicable to Onstream.
1126 */
1127static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1128				   size_t count, loff_t *ppos)
1129{
1130	struct ide_tape_obj *tape = file->private_data;
1131	ide_drive_t *drive = tape->drive;
1132	size_t done = 0;
1133	ssize_t ret = 0;
1134	int rc;
1135
1136	ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1137
1138	if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1139		if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1140			if (count > tape->blk_size &&
1141			    (count % tape->blk_size) == 0)
1142				tape->user_bs_factor = count / tape->blk_size;
1143	}
1144
1145	rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1146	if (rc < 0)
1147		return rc;
1148
1149	while (done < count) {
1150		size_t todo;
1151
1152		/* refill if staging buffer is empty */
1153		if (!tape->valid) {
1154			/* If we are at a filemark, nothing more to read */
1155			if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1156				     &drive->atapi_flags))
1157				break;
1158			/* read */
1159			if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1160						  tape->buffer_size) <= 0)
1161				break;
1162		}
1163
1164		/* copy out */
1165		todo = min_t(size_t, count - done, tape->valid);
1166		if (copy_to_user(buf + done, tape->cur, todo))
1167			ret = -EFAULT;
1168
1169		tape->cur += todo;
1170		tape->valid -= todo;
1171		done += todo;
1172	}
1173
1174	if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1175		idetape_space_over_filemarks(drive, MTFSF, 1);
1176		return 0;
1177	}
1178
1179	return ret ? ret : done;
1180}
1181
1182static ssize_t idetape_chrdev_write(struct file *file, const 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	size_t done = 0;
1188	ssize_t ret = 0;
1189	int rc;
1190
1191	/* The drive is write protected. */
1192	if (tape->write_prot)
1193		return -EACCES;
1194
1195	ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1196
1197	/* Initialize write operation */
1198	rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1199	if (rc < 0)
1200		return rc;
1201
1202	while (done < count) {
1203		size_t todo;
1204
1205		/* flush if staging buffer is full */
1206		if (tape->valid == tape->buffer_size &&
1207		    idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1208					  tape->buffer_size) <= 0)
1209			return rc;
1210
1211		/* copy in */
1212		todo = min_t(size_t, count - done,
1213			     tape->buffer_size - tape->valid);
1214		if (copy_from_user(tape->cur, buf + done, todo))
1215			ret = -EFAULT;
1216
1217		tape->cur += todo;
1218		tape->valid += todo;
1219		done += todo;
1220	}
1221
1222	return ret ? ret : done;
1223}
1224
1225static int idetape_write_filemark(ide_drive_t *drive)
1226{
1227	struct ide_tape_obj *tape = drive->driver_data;
1228	struct ide_atapi_pc pc;
1229
1230	/* Write a filemark */
1231	idetape_create_write_filemark_cmd(drive, &pc, 1);
1232	if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1233		printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1234		return -EIO;
1235	}
1236	return 0;
1237}
1238
1239/*
1240 * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1241 * requested.
1242 *
1243 * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1244 * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1245 * usually not supported.
1246 *
1247 * The following commands are currently not supported:
1248 *
1249 * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1250 * MT_ST_WRITE_THRESHOLD.
1251 */
1252static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1253{
1254	idetape_tape_t *tape = drive->driver_data;
1255	struct gendisk *disk = tape->disk;
1256	struct ide_atapi_pc pc;
1257	int i, retval;
1258
1259	ide_debug_log(IDE_DBG_FUNC, "MTIOCTOP ioctl: mt_op: %d, mt_count: %d",
1260		      mt_op, mt_count);
1261
1262	switch (mt_op) {
1263	case MTFSF:
1264	case MTFSFM:
1265	case MTBSF:
1266	case MTBSFM:
1267		if (!mt_count)
1268			return 0;
1269		return idetape_space_over_filemarks(drive, mt_op, mt_count);
1270	default:
1271		break;
1272	}
1273
1274	switch (mt_op) {
1275	case MTWEOF:
1276		if (tape->write_prot)
1277			return -EACCES;
1278		ide_tape_discard_merge_buffer(drive, 1);
1279		for (i = 0; i < mt_count; i++) {
1280			retval = idetape_write_filemark(drive);
1281			if (retval)
1282				return retval;
1283		}
1284		return 0;
1285	case MTREW:
1286		ide_tape_discard_merge_buffer(drive, 0);
1287		if (idetape_rewind_tape(drive))
1288			return -EIO;
1289		return 0;
1290	case MTLOAD:
1291		ide_tape_discard_merge_buffer(drive, 0);
1292		return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1293	case MTUNLOAD:
1294	case MTOFFL:
1295		/*
1296		 * If door is locked, attempt to unlock before
1297		 * attempting to eject.
1298		 */
1299		if (tape->door_locked) {
1300			if (!ide_set_media_lock(drive, disk, 0))
1301				tape->door_locked = DOOR_UNLOCKED;
1302		}
1303		ide_tape_discard_merge_buffer(drive, 0);
1304		retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1305		if (!retval)
1306			clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1307				  &drive->atapi_flags);
1308		return retval;
1309	case MTNOP:
1310		ide_tape_discard_merge_buffer(drive, 0);
1311		return idetape_flush_tape_buffers(drive);
1312	case MTRETEN:
1313		ide_tape_discard_merge_buffer(drive, 0);
1314		return ide_do_start_stop(drive, disk,
1315			IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1316	case MTEOM:
1317		idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1318		return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1319	case MTERASE:
1320		(void)idetape_rewind_tape(drive);
1321		idetape_create_erase_cmd(&pc);
1322		return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1323	case MTSETBLK:
1324		if (mt_count) {
1325			if (mt_count < tape->blk_size ||
1326			    mt_count % tape->blk_size)
1327				return -EIO;
1328			tape->user_bs_factor = mt_count / tape->blk_size;
1329			clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1330				  &drive->atapi_flags);
1331		} else
1332			set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1333				&drive->atapi_flags);
1334		return 0;
1335	case MTSEEK:
1336		ide_tape_discard_merge_buffer(drive, 0);
1337		return idetape_position_tape(drive,
1338			mt_count * tape->user_bs_factor, tape->partition, 0);
1339	case MTSETPART:
1340		ide_tape_discard_merge_buffer(drive, 0);
1341		return idetape_position_tape(drive, 0, mt_count, 0);
1342	case MTFSR:
1343	case MTBSR:
1344	case MTLOCK:
1345		retval = ide_set_media_lock(drive, disk, 1);
1346		if (retval)
1347			return retval;
1348		tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1349		return 0;
1350	case MTUNLOCK:
1351		retval = ide_set_media_lock(drive, disk, 0);
1352		if (retval)
1353			return retval;
1354		tape->door_locked = DOOR_UNLOCKED;
1355		return 0;
1356	default:
1357		printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1358				mt_op);
1359		return -EIO;
1360	}
1361}
1362
1363/*
1364 * Our character device ioctls. General mtio.h magnetic io commands are
1365 * supported here, and not in the corresponding block interface. Our own
1366 * ide-tape ioctls are supported on both interfaces.
1367 */
1368static long do_idetape_chrdev_ioctl(struct file *file,
1369				unsigned int cmd, unsigned long arg)
1370{
1371	struct ide_tape_obj *tape = file->private_data;
1372	ide_drive_t *drive = tape->drive;
1373	struct mtop mtop;
1374	struct mtget mtget;
1375	struct mtpos mtpos;
1376	int block_offset = 0, position = tape->first_frame;
1377	void __user *argp = (void __user *)arg;
1378
1379	ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x", cmd);
1380
1381	if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1382		ide_tape_flush_merge_buffer(drive);
1383		idetape_flush_tape_buffers(drive);
1384	}
1385	if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1386		block_offset = tape->valid /
1387			(tape->blk_size * tape->user_bs_factor);
1388		position = ide_tape_read_position(drive);
1389		if (position < 0)
1390			return -EIO;
1391	}
1392	switch (cmd) {
1393	case MTIOCTOP:
1394		if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1395			return -EFAULT;
1396		return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1397	case MTIOCGET:
1398		memset(&mtget, 0, sizeof(struct mtget));
1399		mtget.mt_type = MT_ISSCSI2;
1400		mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1401		mtget.mt_dsreg =
1402			((tape->blk_size * tape->user_bs_factor)
1403			 << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1404
1405		if (tape->drv_write_prot)
1406			mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1407
1408		if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1409			return -EFAULT;
1410		return 0;
1411	case MTIOCPOS:
1412		mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1413		if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1414			return -EFAULT;
1415		return 0;
1416	default:
1417		if (tape->chrdev_dir == IDETAPE_DIR_READ)
1418			ide_tape_discard_merge_buffer(drive, 1);
1419		return idetape_blkdev_ioctl(drive, cmd, arg);
1420	}
1421}
1422
1423static long idetape_chrdev_ioctl(struct file *file,
1424				unsigned int cmd, unsigned long arg)
1425{
1426	long ret;
1427	mutex_lock(&ide_tape_mutex);
1428	ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1429	mutex_unlock(&ide_tape_mutex);
1430	return ret;
1431}
1432
1433/*
1434 * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1435 * block size with the reported value.
1436 */
1437static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1438{
1439	idetape_tape_t *tape = drive->driver_data;
1440	struct ide_atapi_pc pc;
1441	u8 buf[12];
1442
1443	idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1444	if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1445		printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1446		if (tape->blk_size == 0) {
1447			printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1448					    "block size, assuming 32k\n");
1449			tape->blk_size = 32768;
1450		}
1451		return;
1452	}
1453	tape->blk_size = (buf[4 + 5] << 16) +
1454				(buf[4 + 6] << 8)  +
1455				 buf[4 + 7];
1456	tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1457
1458	ide_debug_log(IDE_DBG_FUNC, "blk_size: %d, write_prot: %d",
1459		      tape->blk_size, tape->drv_write_prot);
1460}
1461
1462static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1463{
1464	unsigned int minor = iminor(inode), i = minor & ~0xc0;
1465	ide_drive_t *drive;
1466	idetape_tape_t *tape;
1467	int retval;
1468
1469	if (i >= MAX_HWIFS * MAX_DRIVES)
1470		return -ENXIO;
1471
1472	mutex_lock(&idetape_chrdev_mutex);
1473
1474	tape = ide_tape_get(NULL, true, i);
1475	if (!tape) {
1476		mutex_unlock(&idetape_chrdev_mutex);
1477		return -ENXIO;
1478	}
1479
1480	drive = tape->drive;
1481	filp->private_data = tape;
1482
1483	ide_debug_log(IDE_DBG_FUNC, "enter");
1484
1485	/*
1486	 * We really want to do nonseekable_open(inode, filp); here, but some
1487	 * versions of tar incorrectly call lseek on tapes and bail out if that
1488	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1489	 */
1490	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1491
1492
1493	if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1494		retval = -EBUSY;
1495		goto out_put_tape;
1496	}
1497
1498	retval = idetape_wait_ready(drive, 60 * HZ);
1499	if (retval) {
1500		clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1501		printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1502		goto out_put_tape;
1503	}
1504
1505	ide_tape_read_position(drive);
1506	if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1507		(void)idetape_rewind_tape(drive);
1508
1509	/* Read block size and write protect status from drive. */
1510	ide_tape_get_bsize_from_bdesc(drive);
1511
1512	/* Set write protect flag if device is opened as read-only. */
1513	if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1514		tape->write_prot = 1;
1515	else
1516		tape->write_prot = tape->drv_write_prot;
1517
1518	/* Make sure drive isn't write protected if user wants to write. */
1519	if (tape->write_prot) {
1520		if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1521		    (filp->f_flags & O_ACCMODE) == O_RDWR) {
1522			clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1523			retval = -EROFS;
1524			goto out_put_tape;
1525		}
1526	}
1527
1528	/* Lock the tape drive door so user can't eject. */
1529	if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1530		if (!ide_set_media_lock(drive, tape->disk, 1)) {
1531			if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1532				tape->door_locked = DOOR_LOCKED;
1533		}
1534	}
1535	mutex_unlock(&idetape_chrdev_mutex);
1536
1537	return 0;
1538
1539out_put_tape:
1540	ide_tape_put(tape);
1541
1542	mutex_unlock(&idetape_chrdev_mutex);
1543
1544	return retval;
1545}
1546
1547static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1548{
1549	idetape_tape_t *tape = drive->driver_data;
1550
1551	ide_tape_flush_merge_buffer(drive);
1552	tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1553	if (tape->buf != NULL) {
1554		idetape_pad_zeros(drive, tape->blk_size *
1555				(tape->user_bs_factor - 1));
1556		kfree(tape->buf);
1557		tape->buf = NULL;
1558	}
1559	idetape_write_filemark(drive);
1560	idetape_flush_tape_buffers(drive);
1561	idetape_flush_tape_buffers(drive);
1562}
1563
1564static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1565{
1566	struct ide_tape_obj *tape = filp->private_data;
1567	ide_drive_t *drive = tape->drive;
1568	unsigned int minor = iminor(inode);
1569
1570	mutex_lock(&idetape_chrdev_mutex);
1571
1572	tape = drive->driver_data;
1573
1574	ide_debug_log(IDE_DBG_FUNC, "enter");
1575
1576	if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1577		idetape_write_release(drive, minor);
1578	if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1579		if (minor < 128)
1580			ide_tape_discard_merge_buffer(drive, 1);
1581	}
1582
1583	if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1584				    &drive->atapi_flags))
1585		(void) idetape_rewind_tape(drive);
1586
1587	if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1588		if (tape->door_locked == DOOR_LOCKED) {
1589			if (!ide_set_media_lock(drive, tape->disk, 0))
1590				tape->door_locked = DOOR_UNLOCKED;
1591		}
1592	}
1593	clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1594	ide_tape_put(tape);
1595
1596	mutex_unlock(&idetape_chrdev_mutex);
1597
1598	return 0;
1599}
1600
1601static void idetape_get_inquiry_results(ide_drive_t *drive)
1602{
1603	idetape_tape_t *tape = drive->driver_data;
1604	struct ide_atapi_pc pc;
1605	u8 pc_buf[256];
1606	char fw_rev[4], vendor_id[8], product_id[16];
1607
1608	idetape_create_inquiry_cmd(&pc);
1609	if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1610		printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1611				tape->name);
1612		return;
1613	}
1614	memcpy(vendor_id, &pc_buf[8], 8);
1615	memcpy(product_id, &pc_buf[16], 16);
1616	memcpy(fw_rev, &pc_buf[32], 4);
1617
1618	ide_fixstring(vendor_id, 8, 0);
1619	ide_fixstring(product_id, 16, 0);
1620	ide_fixstring(fw_rev, 4, 0);
1621
1622	printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1623			drive->name, tape->name, vendor_id, product_id, fw_rev);
1624}
1625
1626/*
1627 * Ask the tape about its various parameters. In particular, we will adjust our
1628 * data transfer buffer	size to the recommended value as returned by the tape.
1629 */
1630static void idetape_get_mode_sense_results(ide_drive_t *drive)
1631{
1632	idetape_tape_t *tape = drive->driver_data;
1633	struct ide_atapi_pc pc;
1634	u8 buf[24], *caps;
1635	u8 speed, max_speed;
1636
1637	idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1638	if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1639		printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1640				" some default values\n");
1641		tape->blk_size = 512;
1642		put_unaligned(52,   (u16 *)&tape->caps[12]);
1643		put_unaligned(540,  (u16 *)&tape->caps[14]);
1644		put_unaligned(6*52, (u16 *)&tape->caps[16]);
1645		return;
1646	}
1647	caps = buf + 4 + buf[3];
1648
1649	/* convert to host order and save for later use */
1650	speed = be16_to_cpup((__be16 *)&caps[14]);
1651	max_speed = be16_to_cpup((__be16 *)&caps[8]);
1652
1653	*(u16 *)&caps[8] = max_speed;
1654	*(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1655	*(u16 *)&caps[14] = speed;
1656	*(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1657
1658	if (!speed) {
1659		printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1660				"(assuming 650KB/sec)\n", drive->name);
1661		*(u16 *)&caps[14] = 650;
1662	}
1663	if (!max_speed) {
1664		printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1665				"(assuming 650KB/sec)\n", drive->name);
1666		*(u16 *)&caps[8] = 650;
1667	}
1668
1669	memcpy(&tape->caps, caps, 20);
1670
1671	/* device lacks locking support according to capabilities page */
1672	if ((caps[6] & 1) == 0)
1673		drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1674
1675	if (caps[7] & 0x02)
1676		tape->blk_size = 512;
1677	else if (caps[7] & 0x04)
1678		tape->blk_size = 1024;
1679}
1680
1681#ifdef CONFIG_IDE_PROC_FS
1682#define ide_tape_devset_get(name, field) \
1683static int get_##name(ide_drive_t *drive) \
1684{ \
1685	idetape_tape_t *tape = drive->driver_data; \
1686	return tape->field; \
1687}
1688
1689#define ide_tape_devset_set(name, field) \
1690static int set_##name(ide_drive_t *drive, int arg) \
1691{ \
1692	idetape_tape_t *tape = drive->driver_data; \
1693	tape->field = arg; \
1694	return 0; \
1695}
1696
1697#define ide_tape_devset_rw_field(_name, _field) \
1698ide_tape_devset_get(_name, _field) \
1699ide_tape_devset_set(_name, _field) \
1700IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1701
1702#define ide_tape_devset_r_field(_name, _field) \
1703ide_tape_devset_get(_name, _field) \
1704IDE_DEVSET(_name, 0, get_##_name, NULL)
1705
1706static int mulf_tdsc(ide_drive_t *drive)	{ return 1000; }
1707static int divf_tdsc(ide_drive_t *drive)	{ return   HZ; }
1708static int divf_buffer(ide_drive_t *drive)	{ return    2; }
1709static int divf_buffer_size(ide_drive_t *drive)	{ return 1024; }
1710
1711ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1712
1713ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1714
1715ide_tape_devset_r_field(avg_speed, avg_speed);
1716ide_tape_devset_r_field(speed, caps[14]);
1717ide_tape_devset_r_field(buffer, caps[16]);
1718ide_tape_devset_r_field(buffer_size, buffer_size);
1719
1720static const struct ide_proc_devset idetape_settings[] = {
1721	__IDE_PROC_DEVSET(avg_speed,	0, 0xffff, NULL, NULL),
1722	__IDE_PROC_DEVSET(buffer,	0, 0xffff, NULL, divf_buffer),
1723	__IDE_PROC_DEVSET(buffer_size,	0, 0xffff, NULL, divf_buffer_size),
1724	__IDE_PROC_DEVSET(dsc_overlap,	0,      1, NULL, NULL),
1725	__IDE_PROC_DEVSET(speed,	0, 0xffff, NULL, NULL),
1726	__IDE_PROC_DEVSET(tdsc,		IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1727					mulf_tdsc, divf_tdsc),
1728	{ NULL },
1729};
1730#endif
1731
1732/*
1733 * The function below is called to:
1734 *
1735 * 1. Initialize our various state variables.
1736 * 2. Ask the tape for its capabilities.
1737 * 3. Allocate a buffer which will be used for data transfer. The buffer size
1738 * is chosen based on the recommendation which we received in step 2.
1739 *
1740 * Note that at this point ide.c already assigned us an irq, so that we can
1741 * queue requests here and wait for their completion.
1742 */
1743static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1744{
1745	unsigned long t;
1746	int speed;
1747	int buffer_size;
1748	u16 *ctl = (u16 *)&tape->caps[12];
1749
1750	ide_debug_log(IDE_DBG_FUNC, "minor: %d", minor);
1751
1752	drive->pc_callback = ide_tape_callback;
1753
1754	drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1755
1756	if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1757		printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1758				 tape->name);
1759		drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1760	}
1761
1762	/* Seagate Travan drives do not support DSC overlap. */
1763	if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1764		drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1765
1766	tape->minor = minor;
1767	tape->name[0] = 'h';
1768	tape->name[1] = 't';
1769	tape->name[2] = '0' + minor;
1770	tape->chrdev_dir = IDETAPE_DIR_NONE;
1771
1772	idetape_get_inquiry_results(drive);
1773	idetape_get_mode_sense_results(drive);
1774	ide_tape_get_bsize_from_bdesc(drive);
1775	tape->user_bs_factor = 1;
1776	tape->buffer_size = *ctl * tape->blk_size;
1777	while (tape->buffer_size > 0xffff) {
1778		printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1779		*ctl /= 2;
1780		tape->buffer_size = *ctl * tape->blk_size;
1781	}
1782	buffer_size = tape->buffer_size;
1783
1784	/* select the "best" DSC read/write polling freq */
1785	speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1786
1787	t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1788
1789	/*
1790	 * Ensure that the number we got makes sense; limit it within
1791	 * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1792	 */
1793	tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1794					 IDETAPE_DSC_RW_MAX);
1795	printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1796		"%lums tDSC%s\n",
1797		drive->name, tape->name, *(u16 *)&tape->caps[14],
1798		(*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1799		tape->buffer_size / 1024,
1800		tape->best_dsc_rw_freq * 1000 / HZ,
1801		(drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1802
1803	ide_proc_register_driver(drive, tape->driver);
1804}
1805
1806static void ide_tape_remove(ide_drive_t *drive)
1807{
1808	idetape_tape_t *tape = drive->driver_data;
1809
1810	ide_proc_unregister_driver(drive, tape->driver);
1811	device_del(&tape->dev);
1812	ide_unregister_region(tape->disk);
1813
1814	mutex_lock(&idetape_ref_mutex);
1815	put_device(&tape->dev);
1816	mutex_unlock(&idetape_ref_mutex);
1817}
1818
1819static void ide_tape_release(struct device *dev)
1820{
1821	struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1822	ide_drive_t *drive = tape->drive;
1823	struct gendisk *g = tape->disk;
1824
1825	BUG_ON(tape->valid);
1826
1827	drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1828	drive->driver_data = NULL;
1829	device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1830	device_destroy(idetape_sysfs_class,
1831			MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1832	idetape_devs[tape->minor] = NULL;
1833	g->private_data = NULL;
1834	put_disk(g);
1835	kfree(tape);
1836}
1837
1838#ifdef CONFIG_IDE_PROC_FS
1839static int idetape_name_proc_show(struct seq_file *m, void *v)
1840{
1841	ide_drive_t	*drive = (ide_drive_t *) m->private;
1842	idetape_tape_t	*tape = drive->driver_data;
1843
1844	seq_printf(m, "%s\n", tape->name);
1845	return 0;
1846}
1847
1848static int idetape_name_proc_open(struct inode *inode, struct file *file)
1849{
1850	return single_open(file, idetape_name_proc_show, PDE_DATA(inode));
1851}
1852
1853static const struct file_operations idetape_name_proc_fops = {
1854	.owner		= THIS_MODULE,
1855	.open		= idetape_name_proc_open,
1856	.read		= seq_read,
1857	.llseek		= seq_lseek,
1858	.release	= single_release,
1859};
1860
1861static ide_proc_entry_t idetape_proc[] = {
1862	{ "capacity",	S_IFREG|S_IRUGO,	&ide_capacity_proc_fops	},
1863	{ "name",	S_IFREG|S_IRUGO,	&idetape_name_proc_fops	},
1864	{}
1865};
1866
1867static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1868{
1869	return idetape_proc;
1870}
1871
1872static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1873{
1874	return idetape_settings;
1875}
1876#endif
1877
1878static int ide_tape_probe(ide_drive_t *);
1879
1880static struct ide_driver idetape_driver = {
1881	.gen_driver = {
1882		.owner		= THIS_MODULE,
1883		.name		= "ide-tape",
1884		.bus		= &ide_bus_type,
1885	},
1886	.probe			= ide_tape_probe,
1887	.remove			= ide_tape_remove,
1888	.version		= IDETAPE_VERSION,
1889	.do_request		= idetape_do_request,
1890#ifdef CONFIG_IDE_PROC_FS
1891	.proc_entries		= ide_tape_proc_entries,
1892	.proc_devsets		= ide_tape_proc_devsets,
1893#endif
1894};
1895
1896/* Our character device supporting functions, passed to register_chrdev. */
1897static const struct file_operations idetape_fops = {
1898	.owner		= THIS_MODULE,
1899	.read		= idetape_chrdev_read,
1900	.write		= idetape_chrdev_write,
1901	.unlocked_ioctl	= idetape_chrdev_ioctl,
1902	.open		= idetape_chrdev_open,
1903	.release	= idetape_chrdev_release,
1904	.llseek		= noop_llseek,
1905};
1906
1907static int idetape_open(struct block_device *bdev, fmode_t mode)
1908{
1909	struct ide_tape_obj *tape;
1910
1911	mutex_lock(&ide_tape_mutex);
1912	tape = ide_tape_get(bdev->bd_disk, false, 0);
1913	mutex_unlock(&ide_tape_mutex);
1914
1915	if (!tape)
1916		return -ENXIO;
1917
1918	return 0;
1919}
1920
1921static void idetape_release(struct gendisk *disk, fmode_t mode)
1922{
1923	struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1924
1925	mutex_lock(&ide_tape_mutex);
1926	ide_tape_put(tape);
1927	mutex_unlock(&ide_tape_mutex);
1928}
1929
1930static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1931			unsigned int cmd, unsigned long arg)
1932{
1933	struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1934	ide_drive_t *drive = tape->drive;
1935	int err;
1936
1937	mutex_lock(&ide_tape_mutex);
1938	err = generic_ide_ioctl(drive, bdev, cmd, arg);
1939	if (err == -EINVAL)
1940		err = idetape_blkdev_ioctl(drive, cmd, arg);
1941	mutex_unlock(&ide_tape_mutex);
1942
1943	return err;
1944}
1945
1946static const struct block_device_operations idetape_block_ops = {
1947	.owner		= THIS_MODULE,
1948	.open		= idetape_open,
1949	.release	= idetape_release,
1950	.ioctl		= idetape_ioctl,
1951};
1952
1953static int ide_tape_probe(ide_drive_t *drive)
1954{
1955	idetape_tape_t *tape;
1956	struct gendisk *g;
1957	int minor;
1958
1959	ide_debug_log(IDE_DBG_FUNC, "enter");
1960
1961	if (!strstr(DRV_NAME, drive->driver_req))
1962		goto failed;
1963
1964	if (drive->media != ide_tape)
1965		goto failed;
1966
1967	if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1968	    ide_check_atapi_device(drive, DRV_NAME) == 0) {
1969		printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1970				" the driver\n", drive->name);
1971		goto failed;
1972	}
1973	tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1974	if (tape == NULL) {
1975		printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1976				drive->name);
1977		goto failed;
1978	}
1979
1980	g = alloc_disk(1 << PARTN_BITS);
1981	if (!g)
1982		goto out_free_tape;
1983
1984	ide_init_disk(g, drive);
1985
1986	tape->dev.parent = &drive->gendev;
1987	tape->dev.release = ide_tape_release;
1988	dev_set_name(&tape->dev, "%s", dev_name(&drive->gendev));
1989
1990	if (device_register(&tape->dev))
1991		goto out_free_disk;
1992
1993	tape->drive = drive;
1994	tape->driver = &idetape_driver;
1995	tape->disk = g;
1996
1997	g->private_data = &tape->driver;
1998
1999	drive->driver_data = tape;
2000
2001	mutex_lock(&idetape_ref_mutex);
2002	for (minor = 0; idetape_devs[minor]; minor++)
2003		;
2004	idetape_devs[minor] = tape;
2005	mutex_unlock(&idetape_ref_mutex);
2006
2007	idetape_setup(drive, tape, minor);
2008
2009	device_create(idetape_sysfs_class, &drive->gendev,
2010		      MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2011	device_create(idetape_sysfs_class, &drive->gendev,
2012		      MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2013		      "n%s", tape->name);
2014
2015	g->fops = &idetape_block_ops;
2016	ide_register_region(g);
2017
2018	return 0;
2019
2020out_free_disk:
2021	put_disk(g);
2022out_free_tape:
2023	kfree(tape);
2024failed:
2025	return -ENODEV;
2026}
2027
2028static void __exit idetape_exit(void)
2029{
2030	driver_unregister(&idetape_driver.gen_driver);
2031	class_destroy(idetape_sysfs_class);
2032	unregister_chrdev(IDETAPE_MAJOR, "ht");
2033}
2034
2035static int __init idetape_init(void)
2036{
2037	int error = 1;
2038	idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2039	if (IS_ERR(idetape_sysfs_class)) {
2040		idetape_sysfs_class = NULL;
2041		printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2042		error = -EBUSY;
2043		goto out;
2044	}
2045
2046	if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2047		printk(KERN_ERR "ide-tape: Failed to register chrdev"
2048				" interface\n");
2049		error = -EBUSY;
2050		goto out_free_class;
2051	}
2052
2053	error = driver_register(&idetape_driver.gen_driver);
2054	if (error)
2055		goto out_free_driver;
2056
2057	return 0;
2058
2059out_free_driver:
2060	driver_unregister(&idetape_driver.gen_driver);
2061out_free_class:
2062	class_destroy(idetape_sysfs_class);
2063out:
2064	return error;
2065}
2066
2067MODULE_ALIAS("ide:*m-tape*");
2068module_init(idetape_init);
2069module_exit(idetape_exit);
2070MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2071MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2072MODULE_LICENSE("GPL");
2073