Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
[linux-2.6.git] / drivers / ide / ide-tape.c
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/irq.h>
45 #include <linux/uaccess.h>
46 #include <linux/io.h>
47 #include <asm/unaligned.h>
48 #include <linux/mtio.h>
49
50 /* define to see debug info */
51 #undef IDETAPE_DEBUG_LOG
52
53 #ifdef IDETAPE_DEBUG_LOG
54 #define ide_debug_log(lvl, fmt, args...) __ide_debug_log(lvl, fmt, ## args)
55 #else
56 #define ide_debug_log(lvl, fmt, args...) do {} while (0)
57 #endif
58
59 /**************************** Tunable parameters *****************************/
60 /*
61  * After each failed packet command we issue a request sense command and retry
62  * the packet command IDETAPE_MAX_PC_RETRIES times.
63  *
64  * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
65  */
66 #define IDETAPE_MAX_PC_RETRIES          3
67
68 /*
69  * The following parameter is used to select the point in the internal tape fifo
70  * in which we will start to refill the buffer. Decreasing the following
71  * parameter will improve the system's latency and interactive response, while
72  * using a high value might improve system throughput.
73  */
74 #define IDETAPE_FIFO_THRESHOLD          2
75
76 /*
77  * DSC polling parameters.
78  *
79  * Polling for DSC (a single bit in the status register) is a very important
80  * function in ide-tape. There are two cases in which we poll for DSC:
81  *
82  * 1. Before a read/write packet command, to ensure that we can transfer data
83  * from/to the tape's data buffers, without causing an actual media access.
84  * In case the tape is not ready yet, we take out our request from the device
85  * request queue, so that ide.c could service requests from the other device
86  * on the same interface in the meantime.
87  *
88  * 2. After the successful initialization of a "media access packet command",
89  * which is a command that can take a long time to complete (the interval can
90  * range from several seconds to even an hour). Again, we postpone our request
91  * in the middle to free the bus for the other device. The polling frequency
92  * here should be lower than the read/write frequency since those media access
93  * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
94  * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
95  * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
96  *
97  * We also set a timeout for the timer, in case something goes wrong. The
98  * timeout should be longer then the maximum execution time of a tape operation.
99  */
100
101 /* DSC timings. */
102 #define IDETAPE_DSC_RW_MIN              5*HZ/100        /* 50 msec */
103 #define IDETAPE_DSC_RW_MAX              40*HZ/100       /* 400 msec */
104 #define IDETAPE_DSC_RW_TIMEOUT          2*60*HZ         /* 2 minutes */
105 #define IDETAPE_DSC_MA_FAST             2*HZ            /* 2 seconds */
106 #define IDETAPE_DSC_MA_THRESHOLD        5*60*HZ         /* 5 minutes */
107 #define IDETAPE_DSC_MA_SLOW             30*HZ           /* 30 seconds */
108 #define IDETAPE_DSC_MA_TIMEOUT          2*60*60*HZ      /* 2 hours */
109
110 /*************************** End of tunable parameters ***********************/
111
112 /* tape directions */
113 enum {
114         IDETAPE_DIR_NONE  = (1 << 0),
115         IDETAPE_DIR_READ  = (1 << 1),
116         IDETAPE_DIR_WRITE = (1 << 2),
117 };
118
119 /* Tape door status */
120 #define DOOR_UNLOCKED                   0
121 #define DOOR_LOCKED                     1
122 #define DOOR_EXPLICITLY_LOCKED          2
123
124 /* Some defines for the SPACE command */
125 #define IDETAPE_SPACE_OVER_FILEMARK     1
126 #define IDETAPE_SPACE_TO_EOD            3
127
128 /* Some defines for the LOAD UNLOAD command */
129 #define IDETAPE_LU_LOAD_MASK            1
130 #define IDETAPE_LU_RETENSION_MASK       2
131 #define IDETAPE_LU_EOT_MASK             4
132
133 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
134 #define IDETAPE_BLOCK_DESCRIPTOR        0
135 #define IDETAPE_CAPABILITIES_PAGE       0x2a
136
137 /*
138  * Most of our global data which we need to save even as we leave the driver due
139  * to an interrupt or a timer event is stored in the struct defined below.
140  */
141 typedef struct ide_tape_obj {
142         ide_drive_t             *drive;
143         struct ide_driver       *driver;
144         struct gendisk          *disk;
145         struct device           dev;
146
147         /* used by REQ_IDETAPE_{READ,WRITE} requests */
148         struct ide_atapi_pc queued_pc;
149
150         /*
151          * DSC polling variables.
152          *
153          * While polling for DSC we use postponed_rq to postpone the current
154          * request so that ide.c will be able to service pending requests on the
155          * other device. Note that at most we will have only one DSC (usually
156          * data transfer) request in the device request queue.
157          */
158         bool postponed_rq;
159
160         /* The time in which we started polling for DSC */
161         unsigned long dsc_polling_start;
162         /* Timer used to poll for dsc */
163         struct timer_list dsc_timer;
164         /* Read/Write dsc polling frequency */
165         unsigned long best_dsc_rw_freq;
166         unsigned long dsc_poll_freq;
167         unsigned long dsc_timeout;
168
169         /* Read position information */
170         u8 partition;
171         /* Current block */
172         unsigned int first_frame;
173
174         /* Last error information */
175         u8 sense_key, asc, ascq;
176
177         /* Character device operation */
178         unsigned int minor;
179         /* device name */
180         char name[4];
181         /* Current character device data transfer direction */
182         u8 chrdev_dir;
183
184         /* tape block size, usually 512 or 1024 bytes */
185         unsigned short blk_size;
186         int user_bs_factor;
187
188         /* Copy of the tape's Capabilities and Mechanical Page */
189         u8 caps[20];
190
191         /*
192          * Active data transfer request parameters.
193          *
194          * At most, there is only one ide-tape originated data transfer request
195          * in the device request queue. This allows ide.c to easily service
196          * requests from the other device when we postpone our active request.
197          */
198
199         /* Data buffer size chosen based on the tape's recommendation */
200         int buffer_size;
201         /* Staging buffer of buffer_size bytes */
202         void *buf;
203         /* The read/write cursor */
204         void *cur;
205         /* The number of valid bytes in buf */
206         size_t valid;
207
208         /* Measures average tape speed */
209         unsigned long avg_time;
210         int avg_size;
211         int avg_speed;
212
213         /* the door is currently locked */
214         int door_locked;
215         /* the tape hardware is write protected */
216         char drv_write_prot;
217         /* the tape is write protected (hardware or opened as read-only) */
218         char write_prot;
219 } idetape_tape_t;
220
221 static DEFINE_MUTEX(ide_tape_mutex);
222 static DEFINE_MUTEX(idetape_ref_mutex);
223
224 static DEFINE_MUTEX(idetape_chrdev_mutex);
225
226 static struct class *idetape_sysfs_class;
227
228 static void ide_tape_release(struct device *);
229
230 static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
231
232 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk, bool cdev,
233                                          unsigned int i)
234 {
235         struct ide_tape_obj *tape = NULL;
236
237         mutex_lock(&idetape_ref_mutex);
238
239         if (cdev)
240                 tape = idetape_devs[i];
241         else
242                 tape = ide_drv_g(disk, ide_tape_obj);
243
244         if (tape) {
245                 if (ide_device_get(tape->drive))
246                         tape = NULL;
247                 else
248                         get_device(&tape->dev);
249         }
250
251         mutex_unlock(&idetape_ref_mutex);
252         return tape;
253 }
254
255 static void ide_tape_put(struct ide_tape_obj *tape)
256 {
257         ide_drive_t *drive = tape->drive;
258
259         mutex_lock(&idetape_ref_mutex);
260         put_device(&tape->dev);
261         ide_device_put(drive);
262         mutex_unlock(&idetape_ref_mutex);
263 }
264
265 /*
266  * called on each failed packet command retry to analyze the request sense. We
267  * currently do not utilize this information.
268  */
269 static void idetape_analyze_error(ide_drive_t *drive)
270 {
271         idetape_tape_t *tape = drive->driver_data;
272         struct ide_atapi_pc *pc = drive->failed_pc;
273         struct request *rq = drive->hwif->rq;
274         u8 *sense = bio_data(rq->bio);
275
276         tape->sense_key = sense[2] & 0xF;
277         tape->asc       = sense[12];
278         tape->ascq      = sense[13];
279
280         ide_debug_log(IDE_DBG_FUNC,
281                       "cmd: 0x%x, sense key = %x, asc = %x, ascq = %x",
282                       rq->cmd[0], tape->sense_key, tape->asc, tape->ascq);
283
284         /* correct remaining bytes to transfer */
285         if (pc->flags & PC_FLAG_DMA_ERROR)
286                 rq->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
287
288         /*
289          * If error was the result of a zero-length read or write command,
290          * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
291          * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
292          */
293         if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
294             /* length == 0 */
295             && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
296                 if (tape->sense_key == 5) {
297                         /* don't report an error, everything's ok */
298                         pc->error = 0;
299                         /* don't retry read/write */
300                         pc->flags |= PC_FLAG_ABORT;
301                 }
302         }
303         if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
304                 pc->error = IDE_DRV_ERROR_FILEMARK;
305                 pc->flags |= PC_FLAG_ABORT;
306         }
307         if (pc->c[0] == WRITE_6) {
308                 if ((sense[2] & 0x40) || (tape->sense_key == 0xd
309                      && tape->asc == 0x0 && tape->ascq == 0x2)) {
310                         pc->error = IDE_DRV_ERROR_EOD;
311                         pc->flags |= PC_FLAG_ABORT;
312                 }
313         }
314         if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
315                 if (tape->sense_key == 8) {
316                         pc->error = IDE_DRV_ERROR_EOD;
317                         pc->flags |= PC_FLAG_ABORT;
318                 }
319                 if (!(pc->flags & PC_FLAG_ABORT) &&
320                     (blk_rq_bytes(rq) - rq->resid_len))
321                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
322         }
323 }
324
325 static void ide_tape_handle_dsc(ide_drive_t *);
326
327 static int ide_tape_callback(ide_drive_t *drive, int dsc)
328 {
329         idetape_tape_t *tape = drive->driver_data;
330         struct ide_atapi_pc *pc = drive->pc;
331         struct request *rq = drive->hwif->rq;
332         int uptodate = pc->error ? 0 : 1;
333         int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
334
335         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc: %d, err: %d", rq->cmd[0],
336                       dsc, err);
337
338         if (dsc)
339                 ide_tape_handle_dsc(drive);
340
341         if (drive->failed_pc == pc)
342                 drive->failed_pc = NULL;
343
344         if (pc->c[0] == REQUEST_SENSE) {
345                 if (uptodate)
346                         idetape_analyze_error(drive);
347                 else
348                         printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
349                                         "itself - Aborting request!\n");
350         } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
351                 unsigned int blocks =
352                         (blk_rq_bytes(rq) - rq->resid_len) / tape->blk_size;
353
354                 tape->avg_size += blocks * tape->blk_size;
355
356                 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
357                         tape->avg_speed = tape->avg_size * HZ /
358                                 (jiffies - tape->avg_time) / 1024;
359                         tape->avg_size = 0;
360                         tape->avg_time = jiffies;
361                 }
362
363                 tape->first_frame += blocks;
364
365                 if (pc->error) {
366                         uptodate = 0;
367                         err = pc->error;
368                 }
369         }
370         rq->errors = err;
371
372         return uptodate;
373 }
374
375 /*
376  * Postpone the current request so that ide.c will be able to service requests
377  * from another device on the same port while we are polling for DSC.
378  */
379 static void ide_tape_stall_queue(ide_drive_t *drive)
380 {
381         idetape_tape_t *tape = drive->driver_data;
382
383         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc_poll_freq: %lu",
384                       drive->hwif->rq->cmd[0], tape->dsc_poll_freq);
385
386         tape->postponed_rq = true;
387
388         ide_stall_queue(drive, tape->dsc_poll_freq);
389 }
390
391 static void ide_tape_handle_dsc(ide_drive_t *drive)
392 {
393         idetape_tape_t *tape = drive->driver_data;
394
395         /* Media access command */
396         tape->dsc_polling_start = jiffies;
397         tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
398         tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
399         /* Allow ide.c to handle other requests */
400         ide_tape_stall_queue(drive);
401 }
402
403 /*
404  * Packet Command Interface
405  *
406  * The current Packet Command is available in drive->pc, and will not change
407  * until we finish handling it. Each packet command is associated with a
408  * callback function that will be called when the command is finished.
409  *
410  * The handling will be done in three stages:
411  *
412  * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
413  * the interrupt handler to ide_pc_intr.
414  *
415  * 2. On each interrupt, ide_pc_intr will be called. This step will be
416  * repeated until the device signals us that no more interrupts will be issued.
417  *
418  * 3. ATAPI Tape media access commands have immediate status with a delayed
419  * process. In case of a successful initiation of a media access packet command,
420  * the DSC bit will be set when the actual execution of the command is finished.
421  * Since the tape drive will not issue an interrupt, we have to poll for this
422  * event. In this case, we define the request as "low priority request" by
423  * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
424  * exit the driver.
425  *
426  * ide.c will then give higher priority to requests which originate from the
427  * other device, until will change rq_status to RQ_ACTIVE.
428  *
429  * 4. When the packet command is finished, it will be checked for errors.
430  *
431  * 5. In case an error was found, we queue a request sense packet command in
432  * front of the request queue and retry the operation up to
433  * IDETAPE_MAX_PC_RETRIES times.
434  *
435  * 6. In case no error was found, or we decided to give up and not to retry
436  * again, the callback function will be called and then we will handle the next
437  * request.
438  */
439
440 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
441                                          struct ide_cmd *cmd,
442                                          struct ide_atapi_pc *pc)
443 {
444         idetape_tape_t *tape = drive->driver_data;
445         struct request *rq = drive->hwif->rq;
446
447         if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
448                 drive->failed_pc = pc;
449
450         /* Set the current packet command */
451         drive->pc = pc;
452
453         if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
454                 (pc->flags & PC_FLAG_ABORT)) {
455
456                 /*
457                  * We will "abort" retrying a packet command in case legitimate
458                  * error code was received (crossing a filemark, or end of the
459                  * media, for example).
460                  */
461                 if (!(pc->flags & PC_FLAG_ABORT)) {
462                         if (!(pc->c[0] == TEST_UNIT_READY &&
463                               tape->sense_key == 2 && tape->asc == 4 &&
464                              (tape->ascq == 1 || tape->ascq == 8))) {
465                                 printk(KERN_ERR "ide-tape: %s: I/O error, "
466                                                 "pc = %2x, key = %2x, "
467                                                 "asc = %2x, ascq = %2x\n",
468                                                 tape->name, pc->c[0],
469                                                 tape->sense_key, tape->asc,
470                                                 tape->ascq);
471                         }
472                         /* Giving up */
473                         pc->error = IDE_DRV_ERROR_GENERAL;
474                 }
475
476                 drive->failed_pc = NULL;
477                 drive->pc_callback(drive, 0);
478                 ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
479                 return ide_stopped;
480         }
481         ide_debug_log(IDE_DBG_SENSE, "retry #%d, cmd: 0x%02x", pc->retries,
482                       pc->c[0]);
483
484         pc->retries++;
485
486         return ide_issue_pc(drive, cmd);
487 }
488
489 /* A mode sense command is used to "sense" tape parameters. */
490 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
491 {
492         ide_init_pc(pc);
493         pc->c[0] = MODE_SENSE;
494         if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
495                 /* DBD = 1 - Don't return block descriptors */
496                 pc->c[1] = 8;
497         pc->c[2] = page_code;
498         /*
499          * Changed pc->c[3] to 0 (255 will at best return unused info).
500          *
501          * For SCSI this byte is defined as subpage instead of high byte
502          * of length and some IDE drives seem to interpret it this way
503          * and return an error when 255 is used.
504          */
505         pc->c[3] = 0;
506         /* We will just discard data in that case */
507         pc->c[4] = 255;
508         if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
509                 pc->req_xfer = 12;
510         else if (page_code == IDETAPE_CAPABILITIES_PAGE)
511                 pc->req_xfer = 24;
512         else
513                 pc->req_xfer = 50;
514 }
515
516 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
517 {
518         ide_hwif_t *hwif = drive->hwif;
519         idetape_tape_t *tape = drive->driver_data;
520         struct ide_atapi_pc *pc = drive->pc;
521         u8 stat;
522
523         stat = hwif->tp_ops->read_status(hwif);
524
525         if (stat & ATA_DSC) {
526                 if (stat & ATA_ERR) {
527                         /* Error detected */
528                         if (pc->c[0] != TEST_UNIT_READY)
529                                 printk(KERN_ERR "ide-tape: %s: I/O error, ",
530                                                 tape->name);
531                         /* Retry operation */
532                         ide_retry_pc(drive);
533                         return ide_stopped;
534                 }
535                 pc->error = 0;
536         } else {
537                 pc->error = IDE_DRV_ERROR_GENERAL;
538                 drive->failed_pc = NULL;
539         }
540         drive->pc_callback(drive, 0);
541         return ide_stopped;
542 }
543
544 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
545                                    struct ide_atapi_pc *pc, struct request *rq,
546                                    u8 opcode)
547 {
548         unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
549
550         ide_init_pc(pc);
551         put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
552         pc->c[1] = 1;
553
554         if (blk_rq_bytes(rq) == tape->buffer_size)
555                 pc->flags |= PC_FLAG_DMA_OK;
556
557         if (opcode == READ_6)
558                 pc->c[0] = READ_6;
559         else if (opcode == WRITE_6) {
560                 pc->c[0] = WRITE_6;
561                 pc->flags |= PC_FLAG_WRITING;
562         }
563
564         memcpy(rq->cmd, pc->c, 12);
565 }
566
567 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
568                                           struct request *rq, sector_t block)
569 {
570         ide_hwif_t *hwif = drive->hwif;
571         idetape_tape_t *tape = drive->driver_data;
572         struct ide_atapi_pc *pc = NULL;
573         struct ide_cmd cmd;
574         u8 stat;
575
576         ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, sector: %llu, nr_sectors: %u",
577                       rq->cmd[0], (unsigned long long)blk_rq_pos(rq),
578                       blk_rq_sectors(rq));
579
580         BUG_ON(!(rq->cmd_type == REQ_TYPE_SPECIAL ||
581                  rq->cmd_type == REQ_TYPE_SENSE));
582
583         /* Retry a failed packet command */
584         if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
585                 pc = drive->failed_pc;
586                 goto out;
587         }
588
589         /*
590          * If the tape is still busy, postpone our request and service
591          * the other device meanwhile.
592          */
593         stat = hwif->tp_ops->read_status(hwif);
594
595         if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
596             (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
597                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
598
599         if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
600                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
601                 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
602         }
603
604         if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
605             !(stat & ATA_DSC)) {
606                 if (!tape->postponed_rq) {
607                         tape->dsc_polling_start = jiffies;
608                         tape->dsc_poll_freq = tape->best_dsc_rw_freq;
609                         tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
610                 } else if (time_after(jiffies, tape->dsc_timeout)) {
611                         printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
612                                 tape->name);
613                         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
614                                 idetape_media_access_finished(drive);
615                                 return ide_stopped;
616                         } else {
617                                 return ide_do_reset(drive);
618                         }
619                 } else if (time_after(jiffies,
620                                         tape->dsc_polling_start +
621                                         IDETAPE_DSC_MA_THRESHOLD))
622                         tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
623                 ide_tape_stall_queue(drive);
624                 return ide_stopped;
625         } else {
626                 drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
627                 tape->postponed_rq = false;
628         }
629
630         if (rq->cmd[13] & REQ_IDETAPE_READ) {
631                 pc = &tape->queued_pc;
632                 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
633                 goto out;
634         }
635         if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
636                 pc = &tape->queued_pc;
637                 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
638                 goto out;
639         }
640         if (rq->cmd[13] & REQ_IDETAPE_PC1) {
641                 pc = (struct ide_atapi_pc *)rq->special;
642                 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
643                 rq->cmd[13] |= REQ_IDETAPE_PC2;
644                 goto out;
645         }
646         if (rq->cmd[13] & REQ_IDETAPE_PC2) {
647                 idetape_media_access_finished(drive);
648                 return ide_stopped;
649         }
650         BUG();
651
652 out:
653         /* prepare sense request for this command */
654         ide_prep_sense(drive, rq);
655
656         memset(&cmd, 0, sizeof(cmd));
657
658         if (rq_data_dir(rq))
659                 cmd.tf_flags |= IDE_TFLAG_WRITE;
660
661         cmd.rq = rq;
662
663         ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
664         ide_map_sg(drive, &cmd);
665
666         return ide_tape_issue_pc(drive, &cmd, pc);
667 }
668
669 /*
670  * Write a filemark if write_filemark=1. Flush the device buffers without
671  * writing a filemark otherwise.
672  */
673 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
674                 struct ide_atapi_pc *pc, int write_filemark)
675 {
676         ide_init_pc(pc);
677         pc->c[0] = WRITE_FILEMARKS;
678         pc->c[4] = write_filemark;
679         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
680 }
681
682 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
683 {
684         idetape_tape_t *tape = drive->driver_data;
685         struct gendisk *disk = tape->disk;
686         int load_attempted = 0;
687
688         /* Wait for the tape to become ready */
689         set_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT), &drive->atapi_flags);
690         timeout += jiffies;
691         while (time_before(jiffies, timeout)) {
692                 if (ide_do_test_unit_ready(drive, disk) == 0)
693                         return 0;
694                 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
695                     || (tape->asc == 0x3A)) {
696                         /* no media */
697                         if (load_attempted)
698                                 return -ENOMEDIUM;
699                         ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
700                         load_attempted = 1;
701                 /* not about to be ready */
702                 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
703                              (tape->ascq == 1 || tape->ascq == 8)))
704                         return -EIO;
705                 msleep(100);
706         }
707         return -EIO;
708 }
709
710 static int idetape_flush_tape_buffers(ide_drive_t *drive)
711 {
712         struct ide_tape_obj *tape = drive->driver_data;
713         struct ide_atapi_pc pc;
714         int rc;
715
716         idetape_create_write_filemark_cmd(drive, &pc, 0);
717         rc = ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0);
718         if (rc)
719                 return rc;
720         idetape_wait_ready(drive, 60 * 5 * HZ);
721         return 0;
722 }
723
724 static int ide_tape_read_position(ide_drive_t *drive)
725 {
726         idetape_tape_t *tape = drive->driver_data;
727         struct ide_atapi_pc pc;
728         u8 buf[20];
729
730         ide_debug_log(IDE_DBG_FUNC, "enter");
731
732         /* prep cmd */
733         ide_init_pc(&pc);
734         pc.c[0] = READ_POSITION;
735         pc.req_xfer = 20;
736
737         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
738                 return -1;
739
740         if (!pc.error) {
741                 ide_debug_log(IDE_DBG_FUNC, "BOP - %s",
742                                 (buf[0] & 0x80) ? "Yes" : "No");
743                 ide_debug_log(IDE_DBG_FUNC, "EOP - %s",
744                                 (buf[0] & 0x40) ? "Yes" : "No");
745
746                 if (buf[0] & 0x4) {
747                         printk(KERN_INFO "ide-tape: Block location is unknown"
748                                          "to the tape\n");
749                         clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
750                                   &drive->atapi_flags);
751                         return -1;
752                 } else {
753                         ide_debug_log(IDE_DBG_FUNC, "Block Location: %u",
754                                       be32_to_cpup((__be32 *)&buf[4]));
755
756                         tape->partition = buf[1];
757                         tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
758                         set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
759                                 &drive->atapi_flags);
760                 }
761         }
762
763         return tape->first_frame;
764 }
765
766 static void idetape_create_locate_cmd(ide_drive_t *drive,
767                 struct ide_atapi_pc *pc,
768                 unsigned int block, u8 partition, int skip)
769 {
770         ide_init_pc(pc);
771         pc->c[0] = POSITION_TO_ELEMENT;
772         pc->c[1] = 2;
773         put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
774         pc->c[8] = partition;
775         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
776 }
777
778 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
779 {
780         idetape_tape_t *tape = drive->driver_data;
781
782         if (tape->chrdev_dir != IDETAPE_DIR_READ)
783                 return;
784
785         clear_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
786         tape->valid = 0;
787         if (tape->buf != NULL) {
788                 kfree(tape->buf);
789                 tape->buf = NULL;
790         }
791
792         tape->chrdev_dir = IDETAPE_DIR_NONE;
793 }
794
795 /*
796  * Position the tape to the requested block using the LOCATE packet command.
797  * A READ POSITION command is then issued to check where we are positioned. Like
798  * all higher level operations, we queue the commands at the tail of the request
799  * queue and wait for their completion.
800  */
801 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
802                 u8 partition, int skip)
803 {
804         idetape_tape_t *tape = drive->driver_data;
805         struct gendisk *disk = tape->disk;
806         int ret;
807         struct ide_atapi_pc pc;
808
809         if (tape->chrdev_dir == IDETAPE_DIR_READ)
810                 __ide_tape_discard_merge_buffer(drive);
811         idetape_wait_ready(drive, 60 * 5 * HZ);
812         idetape_create_locate_cmd(drive, &pc, block, partition, skip);
813         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
814         if (ret)
815                 return ret;
816
817         ret = ide_tape_read_position(drive);
818         if (ret < 0)
819                 return ret;
820         return 0;
821 }
822
823 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
824                                           int restore_position)
825 {
826         idetape_tape_t *tape = drive->driver_data;
827         int seek, position;
828
829         __ide_tape_discard_merge_buffer(drive);
830         if (restore_position) {
831                 position = ide_tape_read_position(drive);
832                 seek = position > 0 ? position : 0;
833                 if (idetape_position_tape(drive, seek, 0, 0)) {
834                         printk(KERN_INFO "ide-tape: %s: position_tape failed in"
835                                          " %s\n", tape->name, __func__);
836                         return;
837                 }
838         }
839 }
840
841 /*
842  * Generate a read/write request for the block device interface and wait for it
843  * to be serviced.
844  */
845 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
846 {
847         idetape_tape_t *tape = drive->driver_data;
848         struct request *rq;
849         int ret;
850
851         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, size: %d", cmd, size);
852
853         BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
854         BUG_ON(size < 0 || size % tape->blk_size);
855
856         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
857         rq->cmd_type = REQ_TYPE_SPECIAL;
858         rq->cmd[13] = cmd;
859         rq->rq_disk = tape->disk;
860         rq->__sector = tape->first_frame;
861
862         if (size) {
863                 ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
864                                       __GFP_WAIT);
865                 if (ret)
866                         goto out_put;
867         }
868
869         blk_execute_rq(drive->queue, tape->disk, rq, 0);
870
871         /* calculate the number of transferred bytes and update buffer state */
872         size -= rq->resid_len;
873         tape->cur = tape->buf;
874         if (cmd == REQ_IDETAPE_READ)
875                 tape->valid = size;
876         else
877                 tape->valid = 0;
878
879         ret = size;
880         if (rq->errors == IDE_DRV_ERROR_GENERAL)
881                 ret = -EIO;
882 out_put:
883         blk_put_request(rq);
884         return ret;
885 }
886
887 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
888 {
889         ide_init_pc(pc);
890         pc->c[0] = INQUIRY;
891         pc->c[4] = 254;
892         pc->req_xfer = 254;
893 }
894
895 static void idetape_create_rewind_cmd(ide_drive_t *drive,
896                 struct ide_atapi_pc *pc)
897 {
898         ide_init_pc(pc);
899         pc->c[0] = REZERO_UNIT;
900         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
901 }
902
903 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
904 {
905         ide_init_pc(pc);
906         pc->c[0] = ERASE;
907         pc->c[1] = 1;
908         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
909 }
910
911 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
912 {
913         ide_init_pc(pc);
914         pc->c[0] = SPACE;
915         put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
916         pc->c[1] = cmd;
917         pc->flags |= PC_FLAG_WAIT_FOR_DSC;
918 }
919
920 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
921 {
922         idetape_tape_t *tape = drive->driver_data;
923
924         if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
925                 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
926                                 " but we are not writing.\n");
927                 return;
928         }
929         if (tape->buf) {
930                 size_t aligned = roundup(tape->valid, tape->blk_size);
931
932                 memset(tape->cur, 0, aligned - tape->valid);
933                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
934                 kfree(tape->buf);
935                 tape->buf = NULL;
936         }
937         tape->chrdev_dir = IDETAPE_DIR_NONE;
938 }
939
940 static int idetape_init_rw(ide_drive_t *drive, int dir)
941 {
942         idetape_tape_t *tape = drive->driver_data;
943         int rc;
944
945         BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
946
947         if (tape->chrdev_dir == dir)
948                 return 0;
949
950         if (tape->chrdev_dir == IDETAPE_DIR_READ)
951                 ide_tape_discard_merge_buffer(drive, 1);
952         else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
953                 ide_tape_flush_merge_buffer(drive);
954                 idetape_flush_tape_buffers(drive);
955         }
956
957         if (tape->buf || tape->valid) {
958                 printk(KERN_ERR "ide-tape: valid should be 0 now\n");
959                 tape->valid = 0;
960         }
961
962         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
963         if (!tape->buf)
964                 return -ENOMEM;
965         tape->chrdev_dir = dir;
966         tape->cur = tape->buf;
967
968         /*
969          * Issue a 0 rw command to ensure that DSC handshake is
970          * switched from completion mode to buffer available mode.  No
971          * point in issuing this if DSC overlap isn't supported, some
972          * drives (Seagate STT3401A) will return an error.
973          */
974         if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
975                 int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
976                                                   : REQ_IDETAPE_WRITE;
977
978                 rc = idetape_queue_rw_tail(drive, cmd, 0);
979                 if (rc < 0) {
980                         kfree(tape->buf);
981                         tape->buf = NULL;
982                         tape->chrdev_dir = IDETAPE_DIR_NONE;
983                         return rc;
984                 }
985         }
986
987         return 0;
988 }
989
990 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
991 {
992         idetape_tape_t *tape = drive->driver_data;
993
994         memset(tape->buf, 0, tape->buffer_size);
995
996         while (bcount) {
997                 unsigned int count = min(tape->buffer_size, bcount);
998
999                 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);
1000                 bcount -= count;
1001         }
1002 }
1003
1004 /*
1005  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1006  * currently support only one partition.
1007  */
1008 static int idetape_rewind_tape(ide_drive_t *drive)
1009 {
1010         struct ide_tape_obj *tape = drive->driver_data;
1011         struct gendisk *disk = tape->disk;
1012         struct ide_atapi_pc pc;
1013         int ret;
1014
1015         ide_debug_log(IDE_DBG_FUNC, "enter");
1016
1017         idetape_create_rewind_cmd(drive, &pc);
1018         ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1019         if (ret)
1020                 return ret;
1021
1022         ret = ide_tape_read_position(drive);
1023         if (ret < 0)
1024                 return ret;
1025         return 0;
1026 }
1027
1028 /* mtio.h compatible commands should be issued to the chrdev interface. */
1029 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1030                                 unsigned long arg)
1031 {
1032         idetape_tape_t *tape = drive->driver_data;
1033         void __user *argp = (void __user *)arg;
1034
1035         struct idetape_config {
1036                 int dsc_rw_frequency;
1037                 int dsc_media_access_frequency;
1038                 int nr_stages;
1039         } config;
1040
1041         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%04x", cmd);
1042
1043         switch (cmd) {
1044         case 0x0340:
1045                 if (copy_from_user(&config, argp, sizeof(config)))
1046                         return -EFAULT;
1047                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1048                 break;
1049         case 0x0350:
1050                 memset(&config, 0, sizeof(config));
1051                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1052                 config.nr_stages = 1;
1053                 if (copy_to_user(argp, &config, sizeof(config)))
1054                         return -EFAULT;
1055                 break;
1056         default:
1057                 return -EIO;
1058         }
1059         return 0;
1060 }
1061
1062 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1063                                         int mt_count)
1064 {
1065         idetape_tape_t *tape = drive->driver_data;
1066         struct gendisk *disk = tape->disk;
1067         struct ide_atapi_pc pc;
1068         int retval, count = 0;
1069         int sprev = !!(tape->caps[4] & 0x20);
1070
1071
1072         ide_debug_log(IDE_DBG_FUNC, "mt_op: %d, mt_count: %d", mt_op, mt_count);
1073
1074         if (mt_count == 0)
1075                 return 0;
1076         if (MTBSF == mt_op || MTBSFM == mt_op) {
1077                 if (!sprev)
1078                         return -EIO;
1079                 mt_count = -mt_count;
1080         }
1081
1082         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1083                 tape->valid = 0;
1084                 if (test_and_clear_bit(ilog2(IDE_AFLAG_FILEMARK),
1085                                        &drive->atapi_flags))
1086                         ++count;
1087                 ide_tape_discard_merge_buffer(drive, 0);
1088         }
1089
1090         switch (mt_op) {
1091         case MTFSF:
1092         case MTBSF:
1093                 idetape_create_space_cmd(&pc, mt_count - count,
1094                                          IDETAPE_SPACE_OVER_FILEMARK);
1095                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1096         case MTFSFM:
1097         case MTBSFM:
1098                 if (!sprev)
1099                         return -EIO;
1100                 retval = idetape_space_over_filemarks(drive, MTFSF,
1101                                                       mt_count - count);
1102                 if (retval)
1103                         return retval;
1104                 count = (MTBSFM == mt_op ? 1 : -1);
1105                 return idetape_space_over_filemarks(drive, MTFSF, count);
1106         default:
1107                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1108                                 mt_op);
1109                 return -EIO;
1110         }
1111 }
1112
1113 /*
1114  * Our character device read / write functions.
1115  *
1116  * The tape is optimized to maximize throughput when it is transferring an
1117  * integral number of the "continuous transfer limit", which is a parameter of
1118  * the specific tape (26kB on my particular tape, 32kB for Onstream).
1119  *
1120  * As of version 1.3 of the driver, the character device provides an abstract
1121  * continuous view of the media - any mix of block sizes (even 1 byte) on the
1122  * same backup/restore procedure is supported. The driver will internally
1123  * convert the requests to the recommended transfer unit, so that an unmatch
1124  * between the user's block size to the recommended size will only result in a
1125  * (slightly) increased driver overhead, but will no longer hit performance.
1126  * This is not applicable to Onstream.
1127  */
1128 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1129                                    size_t count, loff_t *ppos)
1130 {
1131         struct ide_tape_obj *tape = file->private_data;
1132         ide_drive_t *drive = tape->drive;
1133         size_t done = 0;
1134         ssize_t ret = 0;
1135         int rc;
1136
1137         ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1138
1139         if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1140                 if (test_bit(ilog2(IDE_AFLAG_DETECT_BS), &drive->atapi_flags))
1141                         if (count > tape->blk_size &&
1142                             (count % tape->blk_size) == 0)
1143                                 tape->user_bs_factor = count / tape->blk_size;
1144         }
1145
1146         rc = idetape_init_rw(drive, IDETAPE_DIR_READ);
1147         if (rc < 0)
1148                 return rc;
1149
1150         while (done < count) {
1151                 size_t todo;
1152
1153                 /* refill if staging buffer is empty */
1154                 if (!tape->valid) {
1155                         /* If we are at a filemark, nothing more to read */
1156                         if (test_bit(ilog2(IDE_AFLAG_FILEMARK),
1157                                      &drive->atapi_flags))
1158                                 break;
1159                         /* read */
1160                         if (idetape_queue_rw_tail(drive, REQ_IDETAPE_READ,
1161                                                   tape->buffer_size) <= 0)
1162                                 break;
1163                 }
1164
1165                 /* copy out */
1166                 todo = min_t(size_t, count - done, tape->valid);
1167                 if (copy_to_user(buf + done, tape->cur, todo))
1168                         ret = -EFAULT;
1169
1170                 tape->cur += todo;
1171                 tape->valid -= todo;
1172                 done += todo;
1173         }
1174
1175         if (!done && test_bit(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags)) {
1176                 idetape_space_over_filemarks(drive, MTFSF, 1);
1177                 return 0;
1178         }
1179
1180         return ret ? ret : done;
1181 }
1182
1183 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1184                                      size_t count, loff_t *ppos)
1185 {
1186         struct ide_tape_obj *tape = file->private_data;
1187         ide_drive_t *drive = tape->drive;
1188         size_t done = 0;
1189         ssize_t ret = 0;
1190         int rc;
1191
1192         /* The drive is write protected. */
1193         if (tape->write_prot)
1194                 return -EACCES;
1195
1196         ide_debug_log(IDE_DBG_FUNC, "count %Zd", count);
1197
1198         /* Initialize write operation */
1199         rc = idetape_init_rw(drive, IDETAPE_DIR_WRITE);
1200         if (rc < 0)
1201                 return rc;
1202
1203         while (done < count) {
1204                 size_t todo;
1205
1206                 /* flush if staging buffer is full */
1207                 if (tape->valid == tape->buffer_size &&
1208                     idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1209                                           tape->buffer_size) <= 0)
1210                         return rc;
1211
1212                 /* copy in */
1213                 todo = min_t(size_t, count - done,
1214                              tape->buffer_size - tape->valid);
1215                 if (copy_from_user(tape->cur, buf + done, todo))
1216                         ret = -EFAULT;
1217
1218                 tape->cur += todo;
1219                 tape->valid += todo;
1220                 done += todo;
1221         }
1222
1223         return ret ? ret : done;
1224 }
1225
1226 static int idetape_write_filemark(ide_drive_t *drive)
1227 {
1228         struct ide_tape_obj *tape = drive->driver_data;
1229         struct ide_atapi_pc pc;
1230
1231         /* Write a filemark */
1232         idetape_create_write_filemark_cmd(drive, &pc, 1);
1233         if (ide_queue_pc_tail(drive, tape->disk, &pc, NULL, 0)) {
1234                 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1235                 return -EIO;
1236         }
1237         return 0;
1238 }
1239
1240 /*
1241  * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1242  * requested.
1243  *
1244  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1245  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1246  * usually not supported.
1247  *
1248  * The following commands are currently not supported:
1249  *
1250  * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1251  * MT_ST_WRITE_THRESHOLD.
1252  */
1253 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1254 {
1255         idetape_tape_t *tape = drive->driver_data;
1256         struct gendisk *disk = tape->disk;
1257         struct ide_atapi_pc pc;
1258         int i, retval;
1259
1260         ide_debug_log(IDE_DBG_FUNC, "MTIOCTOP ioctl: mt_op: %d, mt_count: %d",
1261                       mt_op, mt_count);
1262
1263         switch (mt_op) {
1264         case MTFSF:
1265         case MTFSFM:
1266         case MTBSF:
1267         case MTBSFM:
1268                 if (!mt_count)
1269                         return 0;
1270                 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1271         default:
1272                 break;
1273         }
1274
1275         switch (mt_op) {
1276         case MTWEOF:
1277                 if (tape->write_prot)
1278                         return -EACCES;
1279                 ide_tape_discard_merge_buffer(drive, 1);
1280                 for (i = 0; i < mt_count; i++) {
1281                         retval = idetape_write_filemark(drive);
1282                         if (retval)
1283                                 return retval;
1284                 }
1285                 return 0;
1286         case MTREW:
1287                 ide_tape_discard_merge_buffer(drive, 0);
1288                 if (idetape_rewind_tape(drive))
1289                         return -EIO;
1290                 return 0;
1291         case MTLOAD:
1292                 ide_tape_discard_merge_buffer(drive, 0);
1293                 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1294         case MTUNLOAD:
1295         case MTOFFL:
1296                 /*
1297                  * If door is locked, attempt to unlock before
1298                  * attempting to eject.
1299                  */
1300                 if (tape->door_locked) {
1301                         if (!ide_set_media_lock(drive, disk, 0))
1302                                 tape->door_locked = DOOR_UNLOCKED;
1303                 }
1304                 ide_tape_discard_merge_buffer(drive, 0);
1305                 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1306                 if (!retval)
1307                         clear_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1308                                   &drive->atapi_flags);
1309                 return retval;
1310         case MTNOP:
1311                 ide_tape_discard_merge_buffer(drive, 0);
1312                 return idetape_flush_tape_buffers(drive);
1313         case MTRETEN:
1314                 ide_tape_discard_merge_buffer(drive, 0);
1315                 return ide_do_start_stop(drive, disk,
1316                         IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1317         case MTEOM:
1318                 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1319                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1320         case MTERASE:
1321                 (void)idetape_rewind_tape(drive);
1322                 idetape_create_erase_cmd(&pc);
1323                 return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
1324         case MTSETBLK:
1325                 if (mt_count) {
1326                         if (mt_count < tape->blk_size ||
1327                             mt_count % tape->blk_size)
1328                                 return -EIO;
1329                         tape->user_bs_factor = mt_count / tape->blk_size;
1330                         clear_bit(ilog2(IDE_AFLAG_DETECT_BS),
1331                                   &drive->atapi_flags);
1332                 } else
1333                         set_bit(ilog2(IDE_AFLAG_DETECT_BS),
1334                                 &drive->atapi_flags);
1335                 return 0;
1336         case MTSEEK:
1337                 ide_tape_discard_merge_buffer(drive, 0);
1338                 return idetape_position_tape(drive,
1339                         mt_count * tape->user_bs_factor, tape->partition, 0);
1340         case MTSETPART:
1341                 ide_tape_discard_merge_buffer(drive, 0);
1342                 return idetape_position_tape(drive, 0, mt_count, 0);
1343         case MTFSR:
1344         case MTBSR:
1345         case MTLOCK:
1346                 retval = ide_set_media_lock(drive, disk, 1);
1347                 if (retval)
1348                         return retval;
1349                 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1350                 return 0;
1351         case MTUNLOCK:
1352                 retval = ide_set_media_lock(drive, disk, 0);
1353                 if (retval)
1354                         return retval;
1355                 tape->door_locked = DOOR_UNLOCKED;
1356                 return 0;
1357         default:
1358                 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1359                                 mt_op);
1360                 return -EIO;
1361         }
1362 }
1363
1364 /*
1365  * Our character device ioctls. General mtio.h magnetic io commands are
1366  * supported here, and not in the corresponding block interface. Our own
1367  * ide-tape ioctls are supported on both interfaces.
1368  */
1369 static long do_idetape_chrdev_ioctl(struct file *file,
1370                                 unsigned int cmd, unsigned long arg)
1371 {
1372         struct ide_tape_obj *tape = file->private_data;
1373         ide_drive_t *drive = tape->drive;
1374         struct mtop mtop;
1375         struct mtget mtget;
1376         struct mtpos mtpos;
1377         int block_offset = 0, position = tape->first_frame;
1378         void __user *argp = (void __user *)arg;
1379
1380         ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x", cmd);
1381
1382         if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1383                 ide_tape_flush_merge_buffer(drive);
1384                 idetape_flush_tape_buffers(drive);
1385         }
1386         if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1387                 block_offset = tape->valid /
1388                         (tape->blk_size * tape->user_bs_factor);
1389                 position = ide_tape_read_position(drive);
1390                 if (position < 0)
1391                         return -EIO;
1392         }
1393         switch (cmd) {
1394         case MTIOCTOP:
1395                 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1396                         return -EFAULT;
1397                 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1398         case MTIOCGET:
1399                 memset(&mtget, 0, sizeof(struct mtget));
1400                 mtget.mt_type = MT_ISSCSI2;
1401                 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1402                 mtget.mt_dsreg =
1403                         ((tape->blk_size * tape->user_bs_factor)
1404                          << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1405
1406                 if (tape->drv_write_prot)
1407                         mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1408
1409                 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1410                         return -EFAULT;
1411                 return 0;
1412         case MTIOCPOS:
1413                 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1414                 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1415                         return -EFAULT;
1416                 return 0;
1417         default:
1418                 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1419                         ide_tape_discard_merge_buffer(drive, 1);
1420                 return idetape_blkdev_ioctl(drive, cmd, arg);
1421         }
1422 }
1423
1424 static long idetape_chrdev_ioctl(struct file *file,
1425                                 unsigned int cmd, unsigned long arg)
1426 {
1427         long ret;
1428         mutex_lock(&ide_tape_mutex);
1429         ret = do_idetape_chrdev_ioctl(file, cmd, arg);
1430         mutex_unlock(&ide_tape_mutex);
1431         return ret;
1432 }
1433
1434 /*
1435  * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1436  * block size with the reported value.
1437  */
1438 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1439 {
1440         idetape_tape_t *tape = drive->driver_data;
1441         struct ide_atapi_pc pc;
1442         u8 buf[12];
1443
1444         idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1445         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1446                 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1447                 if (tape->blk_size == 0) {
1448                         printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1449                                             "block size, assuming 32k\n");
1450                         tape->blk_size = 32768;
1451                 }
1452                 return;
1453         }
1454         tape->blk_size = (buf[4 + 5] << 16) +
1455                                 (buf[4 + 6] << 8)  +
1456                                  buf[4 + 7];
1457         tape->drv_write_prot = (buf[2] & 0x80) >> 7;
1458
1459         ide_debug_log(IDE_DBG_FUNC, "blk_size: %d, write_prot: %d",
1460                       tape->blk_size, tape->drv_write_prot);
1461 }
1462
1463 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1464 {
1465         unsigned int minor = iminor(inode), i = minor & ~0xc0;
1466         ide_drive_t *drive;
1467         idetape_tape_t *tape;
1468         int retval;
1469
1470         if (i >= MAX_HWIFS * MAX_DRIVES)
1471                 return -ENXIO;
1472
1473         mutex_lock(&idetape_chrdev_mutex);
1474
1475         tape = ide_tape_get(NULL, true, i);
1476         if (!tape) {
1477                 mutex_unlock(&idetape_chrdev_mutex);
1478                 return -ENXIO;
1479         }
1480
1481         drive = tape->drive;
1482         filp->private_data = tape;
1483
1484         ide_debug_log(IDE_DBG_FUNC, "enter");
1485
1486         /*
1487          * We really want to do nonseekable_open(inode, filp); here, but some
1488          * versions of tar incorrectly call lseek on tapes and bail out if that
1489          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1490          */
1491         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1492
1493
1494         if (test_and_set_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags)) {
1495                 retval = -EBUSY;
1496                 goto out_put_tape;
1497         }
1498
1499         retval = idetape_wait_ready(drive, 60 * HZ);
1500         if (retval) {
1501                 clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1502                 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1503                 goto out_put_tape;
1504         }
1505
1506         ide_tape_read_position(drive);
1507         if (!test_bit(ilog2(IDE_AFLAG_ADDRESS_VALID), &drive->atapi_flags))
1508                 (void)idetape_rewind_tape(drive);
1509
1510         /* Read block size and write protect status from drive. */
1511         ide_tape_get_bsize_from_bdesc(drive);
1512
1513         /* Set write protect flag if device is opened as read-only. */
1514         if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1515                 tape->write_prot = 1;
1516         else
1517                 tape->write_prot = tape->drv_write_prot;
1518
1519         /* Make sure drive isn't write protected if user wants to write. */
1520         if (tape->write_prot) {
1521                 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1522                     (filp->f_flags & O_ACCMODE) == O_RDWR) {
1523                         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1524                         retval = -EROFS;
1525                         goto out_put_tape;
1526                 }
1527         }
1528
1529         /* Lock the tape drive door so user can't eject. */
1530         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1531                 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1532                         if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1533                                 tape->door_locked = DOOR_LOCKED;
1534                 }
1535         }
1536         mutex_unlock(&idetape_chrdev_mutex);
1537
1538         return 0;
1539
1540 out_put_tape:
1541         ide_tape_put(tape);
1542
1543         mutex_unlock(&idetape_chrdev_mutex);
1544
1545         return retval;
1546 }
1547
1548 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1549 {
1550         idetape_tape_t *tape = drive->driver_data;
1551
1552         ide_tape_flush_merge_buffer(drive);
1553         tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
1554         if (tape->buf != NULL) {
1555                 idetape_pad_zeros(drive, tape->blk_size *
1556                                 (tape->user_bs_factor - 1));
1557                 kfree(tape->buf);
1558                 tape->buf = NULL;
1559         }
1560         idetape_write_filemark(drive);
1561         idetape_flush_tape_buffers(drive);
1562         idetape_flush_tape_buffers(drive);
1563 }
1564
1565 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1566 {
1567         struct ide_tape_obj *tape = filp->private_data;
1568         ide_drive_t *drive = tape->drive;
1569         unsigned int minor = iminor(inode);
1570
1571         mutex_lock(&idetape_chrdev_mutex);
1572
1573         tape = drive->driver_data;
1574
1575         ide_debug_log(IDE_DBG_FUNC, "enter");
1576
1577         if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1578                 idetape_write_release(drive, minor);
1579         if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1580                 if (minor < 128)
1581                         ide_tape_discard_merge_buffer(drive, 1);
1582         }
1583
1584         if (minor < 128 && test_bit(ilog2(IDE_AFLAG_MEDIUM_PRESENT),
1585                                     &drive->atapi_flags))
1586                 (void) idetape_rewind_tape(drive);
1587
1588         if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1589                 if (tape->door_locked == DOOR_LOCKED) {
1590                         if (!ide_set_media_lock(drive, tape->disk, 0))
1591                                 tape->door_locked = DOOR_UNLOCKED;
1592                 }
1593         }
1594         clear_bit(ilog2(IDE_AFLAG_BUSY), &drive->atapi_flags);
1595         ide_tape_put(tape);
1596
1597         mutex_unlock(&idetape_chrdev_mutex);
1598
1599         return 0;
1600 }
1601
1602 static void idetape_get_inquiry_results(ide_drive_t *drive)
1603 {
1604         idetape_tape_t *tape = drive->driver_data;
1605         struct ide_atapi_pc pc;
1606         u8 pc_buf[256];
1607         char fw_rev[4], vendor_id[8], product_id[16];
1608
1609         idetape_create_inquiry_cmd(&pc);
1610         if (ide_queue_pc_tail(drive, tape->disk, &pc, pc_buf, pc.req_xfer)) {
1611                 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
1612                                 tape->name);
1613                 return;
1614         }
1615         memcpy(vendor_id, &pc_buf[8], 8);
1616         memcpy(product_id, &pc_buf[16], 16);
1617         memcpy(fw_rev, &pc_buf[32], 4);
1618
1619         ide_fixstring(vendor_id, 8, 0);
1620         ide_fixstring(product_id, 16, 0);
1621         ide_fixstring(fw_rev, 4, 0);
1622
1623         printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
1624                         drive->name, tape->name, vendor_id, product_id, fw_rev);
1625 }
1626
1627 /*
1628  * Ask the tape about its various parameters. In particular, we will adjust our
1629  * data transfer buffer size to the recommended value as returned by the tape.
1630  */
1631 static void idetape_get_mode_sense_results(ide_drive_t *drive)
1632 {
1633         idetape_tape_t *tape = drive->driver_data;
1634         struct ide_atapi_pc pc;
1635         u8 buf[24], *caps;
1636         u8 speed, max_speed;
1637
1638         idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
1639         if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer)) {
1640                 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
1641                                 " some default values\n");
1642                 tape->blk_size = 512;
1643                 put_unaligned(52,   (u16 *)&tape->caps[12]);
1644                 put_unaligned(540,  (u16 *)&tape->caps[14]);
1645                 put_unaligned(6*52, (u16 *)&tape->caps[16]);
1646                 return;
1647         }
1648         caps = buf + 4 + buf[3];
1649
1650         /* convert to host order and save for later use */
1651         speed = be16_to_cpup((__be16 *)&caps[14]);
1652         max_speed = be16_to_cpup((__be16 *)&caps[8]);
1653
1654         *(u16 *)&caps[8] = max_speed;
1655         *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
1656         *(u16 *)&caps[14] = speed;
1657         *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
1658
1659         if (!speed) {
1660                 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
1661                                 "(assuming 650KB/sec)\n", drive->name);
1662                 *(u16 *)&caps[14] = 650;
1663         }
1664         if (!max_speed) {
1665                 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
1666                                 "(assuming 650KB/sec)\n", drive->name);
1667                 *(u16 *)&caps[8] = 650;
1668         }
1669
1670         memcpy(&tape->caps, caps, 20);
1671
1672         /* device lacks locking support according to capabilities page */
1673         if ((caps[6] & 1) == 0)
1674                 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
1675
1676         if (caps[7] & 0x02)
1677                 tape->blk_size = 512;
1678         else if (caps[7] & 0x04)
1679                 tape->blk_size = 1024;
1680 }
1681
1682 #ifdef CONFIG_IDE_PROC_FS
1683 #define ide_tape_devset_get(name, field) \
1684 static int get_##name(ide_drive_t *drive) \
1685 { \
1686         idetape_tape_t *tape = drive->driver_data; \
1687         return tape->field; \
1688 }
1689
1690 #define ide_tape_devset_set(name, field) \
1691 static int set_##name(ide_drive_t *drive, int arg) \
1692 { \
1693         idetape_tape_t *tape = drive->driver_data; \
1694         tape->field = arg; \
1695         return 0; \
1696 }
1697
1698 #define ide_tape_devset_rw_field(_name, _field) \
1699 ide_tape_devset_get(_name, _field) \
1700 ide_tape_devset_set(_name, _field) \
1701 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
1702
1703 #define ide_tape_devset_r_field(_name, _field) \
1704 ide_tape_devset_get(_name, _field) \
1705 IDE_DEVSET(_name, 0, get_##_name, NULL)
1706
1707 static int mulf_tdsc(ide_drive_t *drive)        { return 1000; }
1708 static int divf_tdsc(ide_drive_t *drive)        { return   HZ; }
1709 static int divf_buffer(ide_drive_t *drive)      { return    2; }
1710 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
1711
1712 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
1713
1714 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
1715
1716 ide_tape_devset_r_field(avg_speed, avg_speed);
1717 ide_tape_devset_r_field(speed, caps[14]);
1718 ide_tape_devset_r_field(buffer, caps[16]);
1719 ide_tape_devset_r_field(buffer_size, buffer_size);
1720
1721 static const struct ide_proc_devset idetape_settings[] = {
1722         __IDE_PROC_DEVSET(avg_speed,    0, 0xffff, NULL, NULL),
1723         __IDE_PROC_DEVSET(buffer,       0, 0xffff, NULL, divf_buffer),
1724         __IDE_PROC_DEVSET(buffer_size,  0, 0xffff, NULL, divf_buffer_size),
1725         __IDE_PROC_DEVSET(dsc_overlap,  0,      1, NULL, NULL),
1726         __IDE_PROC_DEVSET(speed,        0, 0xffff, NULL, NULL),
1727         __IDE_PROC_DEVSET(tdsc,         IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
1728                                         mulf_tdsc, divf_tdsc),
1729         { NULL },
1730 };
1731 #endif
1732
1733 /*
1734  * The function below is called to:
1735  *
1736  * 1. Initialize our various state variables.
1737  * 2. Ask the tape for its capabilities.
1738  * 3. Allocate a buffer which will be used for data transfer. The buffer size
1739  * is chosen based on the recommendation which we received in step 2.
1740  *
1741  * Note that at this point ide.c already assigned us an irq, so that we can
1742  * queue requests here and wait for their completion.
1743  */
1744 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
1745 {
1746         unsigned long t;
1747         int speed;
1748         int buffer_size;
1749         u16 *ctl = (u16 *)&tape->caps[12];
1750
1751         ide_debug_log(IDE_DBG_FUNC, "minor: %d", minor);
1752
1753         drive->pc_callback = ide_tape_callback;
1754
1755         drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
1756
1757         if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
1758                 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
1759                                  tape->name);
1760                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1761         }
1762
1763         /* Seagate Travan drives do not support DSC overlap. */
1764         if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
1765                 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1766
1767         tape->minor = minor;
1768         tape->name[0] = 'h';
1769         tape->name[1] = 't';
1770         tape->name[2] = '0' + minor;
1771         tape->chrdev_dir = IDETAPE_DIR_NONE;
1772
1773         idetape_get_inquiry_results(drive);
1774         idetape_get_mode_sense_results(drive);
1775         ide_tape_get_bsize_from_bdesc(drive);
1776         tape->user_bs_factor = 1;
1777         tape->buffer_size = *ctl * tape->blk_size;
1778         while (tape->buffer_size > 0xffff) {
1779                 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
1780                 *ctl /= 2;
1781                 tape->buffer_size = *ctl * tape->blk_size;
1782         }
1783         buffer_size = tape->buffer_size;
1784
1785         /* select the "best" DSC read/write polling freq */
1786         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
1787
1788         t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
1789
1790         /*
1791          * Ensure that the number we got makes sense; limit it within
1792          * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
1793          */
1794         tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
1795                                          IDETAPE_DSC_RW_MAX);
1796         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
1797                 "%lums tDSC%s\n",
1798                 drive->name, tape->name, *(u16 *)&tape->caps[14],
1799                 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
1800                 tape->buffer_size / 1024,
1801                 tape->best_dsc_rw_freq * 1000 / HZ,
1802                 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
1803
1804         ide_proc_register_driver(drive, tape->driver);
1805 }
1806
1807 static void ide_tape_remove(ide_drive_t *drive)
1808 {
1809         idetape_tape_t *tape = drive->driver_data;
1810
1811         ide_proc_unregister_driver(drive, tape->driver);
1812         device_del(&tape->dev);
1813         ide_unregister_region(tape->disk);
1814
1815         mutex_lock(&idetape_ref_mutex);
1816         put_device(&tape->dev);
1817         mutex_unlock(&idetape_ref_mutex);
1818 }
1819
1820 static void ide_tape_release(struct device *dev)
1821 {
1822         struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
1823         ide_drive_t *drive = tape->drive;
1824         struct gendisk *g = tape->disk;
1825
1826         BUG_ON(tape->valid);
1827
1828         drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
1829         drive->driver_data = NULL;
1830         device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
1831         device_destroy(idetape_sysfs_class,
1832                         MKDEV(IDETAPE_MAJOR, tape->minor + 128));
1833         idetape_devs[tape->minor] = NULL;
1834         g->private_data = NULL;
1835         put_disk(g);
1836         kfree(tape);
1837 }
1838
1839 #ifdef CONFIG_IDE_PROC_FS
1840 static int idetape_name_proc_show(struct seq_file *m, void *v)
1841 {
1842         ide_drive_t     *drive = (ide_drive_t *) m->private;
1843         idetape_tape_t  *tape = drive->driver_data;
1844
1845         seq_printf(m, "%s\n", tape->name);
1846         return 0;
1847 }
1848
1849 static int idetape_name_proc_open(struct inode *inode, struct file *file)
1850 {
1851         return single_open(file, idetape_name_proc_show, PDE(inode)->data);
1852 }
1853
1854 static const struct file_operations idetape_name_proc_fops = {
1855         .owner          = THIS_MODULE,
1856         .open           = idetape_name_proc_open,
1857         .read           = seq_read,
1858         .llseek         = seq_lseek,
1859         .release        = single_release,
1860 };
1861
1862 static ide_proc_entry_t idetape_proc[] = {
1863         { "capacity",   S_IFREG|S_IRUGO,        &ide_capacity_proc_fops },
1864         { "name",       S_IFREG|S_IRUGO,        &idetape_name_proc_fops },
1865         {}
1866 };
1867
1868 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
1869 {
1870         return idetape_proc;
1871 }
1872
1873 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
1874 {
1875         return idetape_settings;
1876 }
1877 #endif
1878
1879 static int ide_tape_probe(ide_drive_t *);
1880
1881 static struct ide_driver idetape_driver = {
1882         .gen_driver = {
1883                 .owner          = THIS_MODULE,
1884                 .name           = "ide-tape",
1885                 .bus            = &ide_bus_type,
1886         },
1887         .probe                  = ide_tape_probe,
1888         .remove                 = ide_tape_remove,
1889         .version                = IDETAPE_VERSION,
1890         .do_request             = idetape_do_request,
1891 #ifdef CONFIG_IDE_PROC_FS
1892         .proc_entries           = ide_tape_proc_entries,
1893         .proc_devsets           = ide_tape_proc_devsets,
1894 #endif
1895 };
1896
1897 /* Our character device supporting functions, passed to register_chrdev. */
1898 static const struct file_operations idetape_fops = {
1899         .owner          = THIS_MODULE,
1900         .read           = idetape_chrdev_read,
1901         .write          = idetape_chrdev_write,
1902         .unlocked_ioctl = idetape_chrdev_ioctl,
1903         .open           = idetape_chrdev_open,
1904         .release        = idetape_chrdev_release,
1905         .llseek         = noop_llseek,
1906 };
1907
1908 static int idetape_open(struct block_device *bdev, fmode_t mode)
1909 {
1910         struct ide_tape_obj *tape;
1911
1912         mutex_lock(&ide_tape_mutex);
1913         tape = ide_tape_get(bdev->bd_disk, false, 0);
1914         mutex_unlock(&ide_tape_mutex);
1915
1916         if (!tape)
1917                 return -ENXIO;
1918
1919         return 0;
1920 }
1921
1922 static int idetape_release(struct gendisk *disk, fmode_t mode)
1923 {
1924         struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
1925
1926         mutex_lock(&ide_tape_mutex);
1927         ide_tape_put(tape);
1928         mutex_unlock(&ide_tape_mutex);
1929
1930         return 0;
1931 }
1932
1933 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
1934                         unsigned int cmd, unsigned long arg)
1935 {
1936         struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
1937         ide_drive_t *drive = tape->drive;
1938         int err;
1939
1940         mutex_lock(&ide_tape_mutex);
1941         err = generic_ide_ioctl(drive, bdev, cmd, arg);
1942         if (err == -EINVAL)
1943                 err = idetape_blkdev_ioctl(drive, cmd, arg);
1944         mutex_unlock(&ide_tape_mutex);
1945
1946         return err;
1947 }
1948
1949 static const struct block_device_operations idetape_block_ops = {
1950         .owner          = THIS_MODULE,
1951         .open           = idetape_open,
1952         .release        = idetape_release,
1953         .ioctl          = idetape_ioctl,
1954 };
1955
1956 static int ide_tape_probe(ide_drive_t *drive)
1957 {
1958         idetape_tape_t *tape;
1959         struct gendisk *g;
1960         int minor;
1961
1962         ide_debug_log(IDE_DBG_FUNC, "enter");
1963
1964         if (!strstr(DRV_NAME, drive->driver_req))
1965                 goto failed;
1966
1967         if (drive->media != ide_tape)
1968                 goto failed;
1969
1970         if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
1971             ide_check_atapi_device(drive, DRV_NAME) == 0) {
1972                 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
1973                                 " the driver\n", drive->name);
1974                 goto failed;
1975         }
1976         tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
1977         if (tape == NULL) {
1978                 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
1979                                 drive->name);
1980                 goto failed;
1981         }
1982
1983         g = alloc_disk(1 << PARTN_BITS);
1984         if (!g)
1985                 goto out_free_tape;
1986
1987         ide_init_disk(g, drive);
1988
1989         tape->dev.parent = &drive->gendev;
1990         tape->dev.release = ide_tape_release;
1991         dev_set_name(&tape->dev, dev_name(&drive->gendev));
1992
1993         if (device_register(&tape->dev))
1994                 goto out_free_disk;
1995
1996         tape->drive = drive;
1997         tape->driver = &idetape_driver;
1998         tape->disk = g;
1999
2000         g->private_data = &tape->driver;
2001
2002         drive->driver_data = tape;
2003
2004         mutex_lock(&idetape_ref_mutex);
2005         for (minor = 0; idetape_devs[minor]; minor++)
2006                 ;
2007         idetape_devs[minor] = tape;
2008         mutex_unlock(&idetape_ref_mutex);
2009
2010         idetape_setup(drive, tape, minor);
2011
2012         device_create(idetape_sysfs_class, &drive->gendev,
2013                       MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2014         device_create(idetape_sysfs_class, &drive->gendev,
2015                       MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2016                       "n%s", tape->name);
2017
2018         g->fops = &idetape_block_ops;
2019         ide_register_region(g);
2020
2021         return 0;
2022
2023 out_free_disk:
2024         put_disk(g);
2025 out_free_tape:
2026         kfree(tape);
2027 failed:
2028         return -ENODEV;
2029 }
2030
2031 static void __exit idetape_exit(void)
2032 {
2033         driver_unregister(&idetape_driver.gen_driver);
2034         class_destroy(idetape_sysfs_class);
2035         unregister_chrdev(IDETAPE_MAJOR, "ht");
2036 }
2037
2038 static int __init idetape_init(void)
2039 {
2040         int error = 1;
2041         idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2042         if (IS_ERR(idetape_sysfs_class)) {
2043                 idetape_sysfs_class = NULL;
2044                 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2045                 error = -EBUSY;
2046                 goto out;
2047         }
2048
2049         if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2050                 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2051                                 " interface\n");
2052                 error = -EBUSY;
2053                 goto out_free_class;
2054         }
2055
2056         error = driver_register(&idetape_driver.gen_driver);
2057         if (error)
2058                 goto out_free_driver;
2059
2060         return 0;
2061
2062 out_free_driver:
2063         driver_unregister(&idetape_driver.gen_driver);
2064 out_free_class:
2065         class_destroy(idetape_sysfs_class);
2066 out:
2067         return error;
2068 }
2069
2070 MODULE_ALIAS("ide:*m-tape*");
2071 module_init(idetape_init);
2072 module_exit(idetape_exit);
2073 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2074 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2075 MODULE_LICENSE("GPL");