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ocfs2: Fix possible deadlock in quota recovery
[linux-2.6/linux-2.6-openrd.git] / drivers / ide / ide-tape.c
blobcb942a9b580f6ee66bd9f6d50998a664719625c8
1 /*
2 * IDE ATAPI streaming tape driver.
3 *
4 * Copyright (C) 1995-1999 Gadi Oxman <gadio@netvision.net.il>
5 * Copyright (C) 2003-2005 Bartlomiej Zolnierkiewicz
6 *
7 * This driver was constructed as a student project in the software laboratory
8 * of the faculty of electrical engineering in the Technion - Israel's
9 * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
10 *
11 * It is hereby placed under the terms of the GNU general public license.
12 * (See linux/COPYING).
13 *
14 * For a historical changelog see
15 * Documentation/ide/ChangeLog.ide-tape.1995-2002
16 */
17
18 #define DRV_NAME "ide-tape"
19
20 #define IDETAPE_VERSION "1.20"
21
22 #include <linux/module.h>
23 #include <linux/types.h>
24 #include <linux/string.h>
25 #include <linux/kernel.h>
26 #include <linux/delay.h>
27 #include <linux/timer.h>
28 #include <linux/mm.h>
29 #include <linux/interrupt.h>
30 #include <linux/jiffies.h>
31 #include <linux/major.h>
32 #include <linux/errno.h>
33 #include <linux/genhd.h>
34 #include <linux/slab.h>
35 #include <linux/pci.h>
36 #include <linux/ide.h>
37 #include <linux/smp_lock.h>
38 #include <linux/completion.h>
39 #include <linux/bitops.h>
40 #include <linux/mutex.h>
41 #include <scsi/scsi.h>
42
43 #include <asm/byteorder.h>
44 #include <linux/irq.h>
45 #include <linux/uaccess.h>
46 #include <linux/io.h>
47 #include <asm/unaligned.h>
48 #include <linux/mtio.h>
49
50 enum {
51 /* output errors only */
52 DBG_ERR = (1 << 0),
53 /* output all sense key/asc */
54 DBG_SENSE = (1 << 1),
55 /* info regarding all chrdev-related procedures */
56 DBG_CHRDEV = (1 << 2),
57 /* all remaining procedures */
58 DBG_PROCS = (1 << 3),
59 };
60
61 /* define to see debug info */
62 #define IDETAPE_DEBUG_LOG 0
63
64 #if IDETAPE_DEBUG_LOG
65 #define debug_log(lvl, fmt, args...) \
66 { \
67 if (tape->debug_mask & lvl) \
68 printk(KERN_INFO "ide-tape: " fmt, ## args); \
69 }
70 #else
71 #define debug_log(lvl, fmt, args...) do {} while (0)
72 #endif
73
74 /**************************** Tunable parameters *****************************/
75 /*
76 * After each failed packet command we issue a request sense command and retry
77 * the packet command IDETAPE_MAX_PC_RETRIES times.
78 *
79 * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
80 */
81 #define IDETAPE_MAX_PC_RETRIES 3
82
83 /*
84 * The following parameter is used to select the point in the internal tape fifo
85 * in which we will start to refill the buffer. Decreasing the following
86 * parameter will improve the system's latency and interactive response, while
87 * using a high value might improve system throughput.
88 */
89 #define IDETAPE_FIFO_THRESHOLD 2
90
91 /*
92 * DSC polling parameters.
93 *
94 * Polling for DSC (a single bit in the status register) is a very important
95 * function in ide-tape. There are two cases in which we poll for DSC:
96 *
97 * 1. Before a read/write packet command, to ensure that we can transfer data
98 * from/to the tape's data buffers, without causing an actual media access.
99 * In case the tape is not ready yet, we take out our request from the device
100 * request queue, so that ide.c could service requests from the other device
101 * on the same interface in the meantime.
102 *
103 * 2. After the successful initialization of a "media access packet command",
104 * which is a command that can take a long time to complete (the interval can
105 * range from several seconds to even an hour). Again, we postpone our request
106 * in the middle to free the bus for the other device. The polling frequency
107 * here should be lower than the read/write frequency since those media access
108 * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
109 * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
110 * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
111 *
112 * We also set a timeout for the timer, in case something goes wrong. The
113 * timeout should be longer then the maximum execution time of a tape operation.
114 */
115
116 /* DSC timings. */
117 #define IDETAPE_DSC_RW_MIN 5*HZ/100 /* 50 msec */
118 #define IDETAPE_DSC_RW_MAX 40*HZ/100 /* 400 msec */
119 #define IDETAPE_DSC_RW_TIMEOUT 2*60*HZ /* 2 minutes */
120 #define IDETAPE_DSC_MA_FAST 2*HZ /* 2 seconds */
121 #define IDETAPE_DSC_MA_THRESHOLD 5*60*HZ /* 5 minutes */
122 #define IDETAPE_DSC_MA_SLOW 30*HZ /* 30 seconds */
123 #define IDETAPE_DSC_MA_TIMEOUT 2*60*60*HZ /* 2 hours */
124
125 /*************************** End of tunable parameters ***********************/
126
127 /* tape directions */
128 enum {
129 IDETAPE_DIR_NONE = (1 << 0),
130 IDETAPE_DIR_READ = (1 << 1),
131 IDETAPE_DIR_WRITE = (1 << 2),
132 };
133
134 struct idetape_bh {
135 u32 b_size;
136 atomic_t b_count;
137 struct idetape_bh *b_reqnext;
138 char *b_data;
139 };
140
141 /* Tape door status */
142 #define DOOR_UNLOCKED 0
143 #define DOOR_LOCKED 1
144 #define DOOR_EXPLICITLY_LOCKED 2
145
146 /* Some defines for the SPACE command */
147 #define IDETAPE_SPACE_OVER_FILEMARK 1
148 #define IDETAPE_SPACE_TO_EOD 3
149
150 /* Some defines for the LOAD UNLOAD command */
151 #define IDETAPE_LU_LOAD_MASK 1
152 #define IDETAPE_LU_RETENSION_MASK 2
153 #define IDETAPE_LU_EOT_MASK 4
154
155 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
156 #define IDETAPE_BLOCK_DESCRIPTOR 0
157 #define IDETAPE_CAPABILITIES_PAGE 0x2a
158
159 /*
160 * Most of our global data which we need to save even as we leave the driver due
161 * to an interrupt or a timer event is stored in the struct defined below.
162 */
163 typedef struct ide_tape_obj {
164 ide_drive_t *drive;
165 struct ide_driver *driver;
166 struct gendisk *disk;
167 struct device dev;
168
169 /* used by REQ_IDETAPE_{READ,WRITE} requests */
170 struct ide_atapi_pc queued_pc;
171
172 /*
173 * DSC polling variables.
174 *
175 * While polling for DSC we use postponed_rq to postpone the current
176 * request so that ide.c will be able to service pending requests on the
177 * other device. Note that at most we will have only one DSC (usually
178 * data transfer) request in the device request queue.
179 */
180 struct request *postponed_rq;
181 /* The time in which we started polling for DSC */
182 unsigned long dsc_polling_start;
183 /* Timer used to poll for dsc */
184 struct timer_list dsc_timer;
185 /* Read/Write dsc polling frequency */
186 unsigned long best_dsc_rw_freq;
187 unsigned long dsc_poll_freq;
188 unsigned long dsc_timeout;
189
190 /* Read position information */
191 u8 partition;
192 /* Current block */
193 unsigned int first_frame;
194
195 /* Last error information */
196 u8 sense_key, asc, ascq;
197
198 /* Character device operation */
199 unsigned int minor;
200 /* device name */
201 char name[4];
202 /* Current character device data transfer direction */
203 u8 chrdev_dir;
204
205 /* tape block size, usually 512 or 1024 bytes */
206 unsigned short blk_size;
207 int user_bs_factor;
208
209 /* Copy of the tape's Capabilities and Mechanical Page */
210 u8 caps[20];
211
212 /*
213 * Active data transfer request parameters.
214 *
215 * At most, there is only one ide-tape originated data transfer request
216 * in the device request queue. This allows ide.c to easily service
217 * requests from the other device when we postpone our active request.
218 */
219
220 /* Data buffer size chosen based on the tape's recommendation */
221 int buffer_size;
222 /* merge buffer */
223 struct idetape_bh *merge_bh;
224 /* size of the merge buffer */
225 int merge_bh_size;
226 /* pointer to current buffer head within the merge buffer */
227 struct idetape_bh *bh;
228 char *b_data;
229 int b_count;
230
231 int pages_per_buffer;
232 /* Wasted space in each stage */
233 int excess_bh_size;
234
235 /* Measures average tape speed */
236 unsigned long avg_time;
237 int avg_size;
238 int avg_speed;
239
240 /* the door is currently locked */
241 int door_locked;
242 /* the tape hardware is write protected */
243 char drv_write_prot;
244 /* the tape is write protected (hardware or opened as read-only) */
245 char write_prot;
246
247 u32 debug_mask;
248 } idetape_tape_t;
249
250 static DEFINE_MUTEX(idetape_ref_mutex);
251
252 static struct class *idetape_sysfs_class;
253
254 static void ide_tape_release(struct device *);
255
256 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
257 {
258 struct ide_tape_obj *tape = NULL;
259
260 mutex_lock(&idetape_ref_mutex);
261 tape = ide_drv_g(disk, ide_tape_obj);
262 if (tape) {
263 if (ide_device_get(tape->drive))
264 tape = NULL;
265 else
266 get_device(&tape->dev);
267 }
268 mutex_unlock(&idetape_ref_mutex);
269 return tape;
270 }
271
272 static void ide_tape_put(struct ide_tape_obj *tape)
273 {
274 ide_drive_t *drive = tape->drive;
275
276 mutex_lock(&idetape_ref_mutex);
277 put_device(&tape->dev);
278 ide_device_put(drive);
279 mutex_unlock(&idetape_ref_mutex);
280 }
281
282 /*
283 * The variables below are used for the character device interface. Additional
284 * state variables are defined in our ide_drive_t structure.
285 */
286 static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
287
288 static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
289 {
290 struct ide_tape_obj *tape = NULL;
291
292 mutex_lock(&idetape_ref_mutex);
293 tape = idetape_devs[i];
294 if (tape)
295 get_device(&tape->dev);
296 mutex_unlock(&idetape_ref_mutex);
297 return tape;
298 }
299
300 static int idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
301 unsigned int bcount)
302 {
303 struct idetape_bh *bh = pc->bh;
304 int count;
305
306 while (bcount) {
307 if (bh == NULL)
308 break;
309 count = min(
310 (unsigned int)(bh->b_size - atomic_read(&bh->b_count)),
311 bcount);
312 drive->hwif->tp_ops->input_data(drive, NULL, bh->b_data +
313 atomic_read(&bh->b_count), count);
314 bcount -= count;
315 atomic_add(count, &bh->b_count);
316 if (atomic_read(&bh->b_count) == bh->b_size) {
317 bh = bh->b_reqnext;
318 if (bh)
319 atomic_set(&bh->b_count, 0);
320 }
321 }
322
323 pc->bh = bh;
324
325 return bcount;
326 }
327
328 static int idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
329 unsigned int bcount)
330 {
331 struct idetape_bh *bh = pc->bh;
332 int count;
333
334 while (bcount) {
335 if (bh == NULL)
336 break;
337 count = min((unsigned int)pc->b_count, (unsigned int)bcount);
338 drive->hwif->tp_ops->output_data(drive, NULL, pc->b_data, count);
339 bcount -= count;
340 pc->b_data += count;
341 pc->b_count -= count;
342 if (!pc->b_count) {
343 bh = bh->b_reqnext;
344 pc->bh = bh;
345 if (bh) {
346 pc->b_data = bh->b_data;
347 pc->b_count = atomic_read(&bh->b_count);
348 }
349 }
350 }
351
352 return bcount;
353 }
354
355 static void idetape_update_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc)
356 {
357 struct idetape_bh *bh = pc->bh;
358 int count;
359 unsigned int bcount = pc->xferred;
360
361 if (pc->flags & PC_FLAG_WRITING)
362 return;
363 while (bcount) {
364 if (bh == NULL) {
365 printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
366 __func__);
367 return;
368 }
369 count = min((unsigned int)bh->b_size, (unsigned int)bcount);
370 atomic_set(&bh->b_count, count);
371 if (atomic_read(&bh->b_count) == bh->b_size)
372 bh = bh->b_reqnext;
373 bcount -= count;
374 }
375 pc->bh = bh;
376 }
377
378 /*
379 * called on each failed packet command retry to analyze the request sense. We
380 * currently do not utilize this information.
381 */
382 static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
383 {
384 idetape_tape_t *tape = drive->driver_data;
385 struct ide_atapi_pc *pc = drive->failed_pc;
386
387 tape->sense_key = sense[2] & 0xF;
388 tape->asc = sense[12];
389 tape->ascq = sense[13];
390
391 debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
392 pc->c[0], tape->sense_key, tape->asc, tape->ascq);
393
394 /* Correct pc->xferred by asking the tape. */
395 if (pc->flags & PC_FLAG_DMA_ERROR) {
396 pc->xferred = pc->req_xfer -
397 tape->blk_size *
398 get_unaligned_be32(&sense[3]);
399 idetape_update_buffers(drive, pc);
400 }
401
402 /*
403 * If error was the result of a zero-length read or write command,
404 * with sense key=5, asc=0x22, ascq=0, let it slide. Some drives
405 * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
406 */
407 if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
408 /* length == 0 */
409 && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
410 if (tape->sense_key == 5) {
411 /* don't report an error, everything's ok */
412 pc->error = 0;
413 /* don't retry read/write */
414 pc->flags |= PC_FLAG_ABORT;
415 }
416 }
417 if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
418 pc->error = IDE_DRV_ERROR_FILEMARK;
419 pc->flags |= PC_FLAG_ABORT;
420 }
421 if (pc->c[0] == WRITE_6) {
422 if ((sense[2] & 0x40) || (tape->sense_key == 0xd
423 && tape->asc == 0x0 && tape->ascq == 0x2)) {
424 pc->error = IDE_DRV_ERROR_EOD;
425 pc->flags |= PC_FLAG_ABORT;
426 }
427 }
428 if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
429 if (tape->sense_key == 8) {
430 pc->error = IDE_DRV_ERROR_EOD;
431 pc->flags |= PC_FLAG_ABORT;
432 }
433 if (!(pc->flags & PC_FLAG_ABORT) &&
434 pc->xferred)
435 pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
436 }
437 }
438
439 /* Free data buffers completely. */
440 static void ide_tape_kfree_buffer(idetape_tape_t *tape)
441 {
442 struct idetape_bh *prev_bh, *bh = tape->merge_bh;
443
444 while (bh) {
445 u32 size = bh->b_size;
446
447 while (size) {
448 unsigned int order = fls(size >> PAGE_SHIFT)-1;
449
450 if (bh->b_data)
451 free_pages((unsigned long)bh->b_data, order);
452
453 size &= (order-1);
454 bh->b_data += (1 << order) * PAGE_SIZE;
455 }
456 prev_bh = bh;
457 bh = bh->b_reqnext;
458 kfree(prev_bh);
459 }
460 }
461
462 static void ide_tape_handle_dsc(ide_drive_t *);
463
464 static int ide_tape_callback(ide_drive_t *drive, int dsc)
465 {
466 idetape_tape_t *tape = drive->driver_data;
467 struct ide_atapi_pc *pc = drive->pc;
468 struct request *rq = drive->hwif->rq;
469 int uptodate = pc->error ? 0 : 1;
470 int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
471
472 debug_log(DBG_PROCS, "Enter %s\n", __func__);
473
474 if (dsc)
475 ide_tape_handle_dsc(drive);
476
477 if (drive->failed_pc == pc)
478 drive->failed_pc = NULL;
479
480 if (pc->c[0] == REQUEST_SENSE) {
481 if (uptodate)
482 idetape_analyze_error(drive, pc->buf);
483 else
484 printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
485 "itself - Aborting request!\n");
486 } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
487 int blocks = pc->xferred / tape->blk_size;
488
489 tape->avg_size += blocks * tape->blk_size;
490
491 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
492 tape->avg_speed = tape->avg_size * HZ /
493 (jiffies - tape->avg_time) / 1024;
494 tape->avg_size = 0;
495 tape->avg_time = jiffies;
496 }
497
498 tape->first_frame += blocks;
499 rq->current_nr_sectors -= blocks;
500
501 if (pc->error) {
502 uptodate = 0;
503 err = pc->error;
504 }
505 } else if (pc->c[0] == READ_POSITION && uptodate) {
506 u8 *readpos = pc->buf;
507
508 debug_log(DBG_SENSE, "BOP - %s\n",
509 (readpos[0] & 0x80) ? "Yes" : "No");
510 debug_log(DBG_SENSE, "EOP - %s\n",
511 (readpos[0] & 0x40) ? "Yes" : "No");
512
513 if (readpos[0] & 0x4) {
514 printk(KERN_INFO "ide-tape: Block location is unknown"
515 "to the tape\n");
516 clear_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
517 uptodate = 0;
518 err = IDE_DRV_ERROR_GENERAL;
519 } else {
520 debug_log(DBG_SENSE, "Block Location - %u\n",
521 be32_to_cpup((__be32 *)&readpos[4]));
522
523 tape->partition = readpos[1];
524 tape->first_frame = be32_to_cpup((__be32 *)&readpos[4]);
525 set_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
526 }
527 }
528
529 rq->errors = err;
530
531 return uptodate;
532 }
533
534 /*
535 * Postpone the current request so that ide.c will be able to service requests
536 * from another device on the same port while we are polling for DSC.
537 */
538 static void idetape_postpone_request(ide_drive_t *drive)
539 {
540 idetape_tape_t *tape = drive->driver_data;
541
542 debug_log(DBG_PROCS, "Enter %s\n", __func__);
543
544 tape->postponed_rq = drive->hwif->rq;
545
546 ide_stall_queue(drive, tape->dsc_poll_freq);
547 }
548
549 static void ide_tape_handle_dsc(ide_drive_t *drive)
550 {
551 idetape_tape_t *tape = drive->driver_data;
552
553 /* Media access command */
554 tape->dsc_polling_start = jiffies;
555 tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
556 tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
557 /* Allow ide.c to handle other requests */
558 idetape_postpone_request(drive);
559 }
560
561 static int ide_tape_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
562 unsigned int bcount, int write)
563 {
564 unsigned int bleft;
565
566 if (write)
567 bleft = idetape_output_buffers(drive, pc, bcount);
568 else
569 bleft = idetape_input_buffers(drive, pc, bcount);
570
571 return bcount - bleft;
572 }
573
574 /*
575 * Packet Command Interface
576 *
577 * The current Packet Command is available in drive->pc, and will not change
578 * until we finish handling it. Each packet command is associated with a
579 * callback function that will be called when the command is finished.
580 *
581 * The handling will be done in three stages:
582 *
583 * 1. ide_tape_issue_pc will send the packet command to the drive, and will set
584 * the interrupt handler to ide_pc_intr.
585 *
586 * 2. On each interrupt, ide_pc_intr will be called. This step will be
587 * repeated until the device signals us that no more interrupts will be issued.
588 *
589 * 3. ATAPI Tape media access commands have immediate status with a delayed
590 * process. In case of a successful initiation of a media access packet command,
591 * the DSC bit will be set when the actual execution of the command is finished.
592 * Since the tape drive will not issue an interrupt, we have to poll for this
593 * event. In this case, we define the request as "low priority request" by
594 * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
595 * exit the driver.
596 *
597 * ide.c will then give higher priority to requests which originate from the
598 * other device, until will change rq_status to RQ_ACTIVE.
599 *
600 * 4. When the packet command is finished, it will be checked for errors.
601 *
602 * 5. In case an error was found, we queue a request sense packet command in
603 * front of the request queue and retry the operation up to
604 * IDETAPE_MAX_PC_RETRIES times.
605 *
606 * 6. In case no error was found, or we decided to give up and not to retry
607 * again, the callback function will be called and then we will handle the next
608 * request.
609 */
610
611 static ide_startstop_t ide_tape_issue_pc(ide_drive_t *drive,
612 struct ide_cmd *cmd,
613 struct ide_atapi_pc *pc)
614 {
615 idetape_tape_t *tape = drive->driver_data;
616
617 if (drive->pc->c[0] == REQUEST_SENSE &&
618 pc->c[0] == REQUEST_SENSE) {
619 printk(KERN_ERR "ide-tape: possible ide-tape.c bug - "
620 "Two request sense in serial were issued\n");
621 }
622
623 if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
624 drive->failed_pc = pc;
625
626 /* Set the current packet command */
627 drive->pc = pc;
628
629 if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
630 (pc->flags & PC_FLAG_ABORT)) {
631 /*
632 * We will "abort" retrying a packet command in case legitimate
633 * error code was received (crossing a filemark, or end of the
634 * media, for example).
635 */
636 if (!(pc->flags & PC_FLAG_ABORT)) {
637 if (!(pc->c[0] == TEST_UNIT_READY &&
638 tape->sense_key == 2 && tape->asc == 4 &&
639 (tape->ascq == 1 || tape->ascq == 8))) {
640 printk(KERN_ERR "ide-tape: %s: I/O error, "
641 "pc = %2x, key = %2x, "
642 "asc = %2x, ascq = %2x\n",
643 tape->name, pc->c[0],
644 tape->sense_key, tape->asc,
645 tape->ascq);
646 }
647 /* Giving up */
648 pc->error = IDE_DRV_ERROR_GENERAL;
649 }
650 drive->failed_pc = NULL;
651 drive->pc_callback(drive, 0);
652 return ide_stopped;
653 }
654 debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
655
656 pc->retries++;
657
658 return ide_issue_pc(drive, cmd);
659 }
660
661 /* A mode sense command is used to "sense" tape parameters. */
662 static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
663 {
664 ide_init_pc(pc);
665 pc->c[0] = MODE_SENSE;
666 if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
667 /* DBD = 1 - Don't return block descriptors */
668 pc->c[1] = 8;
669 pc->c[2] = page_code;
670 /*
671 * Changed pc->c[3] to 0 (255 will at best return unused info).
672 *
673 * For SCSI this byte is defined as subpage instead of high byte
674 * of length and some IDE drives seem to interpret it this way
675 * and return an error when 255 is used.
676 */
677 pc->c[3] = 0;
678 /* We will just discard data in that case */
679 pc->c[4] = 255;
680 if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
681 pc->req_xfer = 12;
682 else if (page_code == IDETAPE_CAPABILITIES_PAGE)
683 pc->req_xfer = 24;
684 else
685 pc->req_xfer = 50;
686 }
687
688 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
689 {
690 ide_hwif_t *hwif = drive->hwif;
691 idetape_tape_t *tape = drive->driver_data;
692 struct ide_atapi_pc *pc = drive->pc;
693 u8 stat;
694
695 stat = hwif->tp_ops->read_status(hwif);
696
697 if (stat & ATA_DSC) {
698 if (stat & ATA_ERR) {
699 /* Error detected */
700 if (pc->c[0] != TEST_UNIT_READY)
701 printk(KERN_ERR "ide-tape: %s: I/O error, ",
702 tape->name);
703 /* Retry operation */
704 ide_retry_pc(drive, tape->disk);
705 return ide_stopped;
706 }
707 pc->error = 0;
708 } else {
709 pc->error = IDE_DRV_ERROR_GENERAL;
710 drive->failed_pc = NULL;
711 }
712 drive->pc_callback(drive, 0);
713 return ide_stopped;
714 }
715
716 static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
717 struct ide_atapi_pc *pc, struct request *rq,
718 u8 opcode)
719 {
720 struct idetape_bh *bh = (struct idetape_bh *)rq->special;
721 unsigned int length = rq->current_nr_sectors;
722
723 ide_init_pc(pc);
724 put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
725 pc->c[1] = 1;
726 pc->bh = bh;
727 pc->buf = NULL;
728 pc->buf_size = length * tape->blk_size;
729 pc->req_xfer = pc->buf_size;
730 if (pc->req_xfer == tape->buffer_size)
731 pc->flags |= PC_FLAG_DMA_OK;
732
733 if (opcode == READ_6) {
734 pc->c[0] = READ_6;
735 atomic_set(&bh->b_count, 0);
736 } else if (opcode == WRITE_6) {
737 pc->c[0] = WRITE_6;
738 pc->flags |= PC_FLAG_WRITING;
739 pc->b_data = bh->b_data;
740 pc->b_count = atomic_read(&bh->b_count);
741 }
742
743 memcpy(rq->cmd, pc->c, 12);
744 }
745
746 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
747 struct request *rq, sector_t block)
748 {
749 ide_hwif_t *hwif = drive->hwif;
750 idetape_tape_t *tape = drive->driver_data;
751 struct ide_atapi_pc *pc = NULL;
752 struct request *postponed_rq = tape->postponed_rq;
753 struct ide_cmd cmd;
754 u8 stat;
755
756 debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %lu,"
757 " current_nr_sectors: %u\n",
758 (unsigned long long)rq->sector, rq->nr_sectors,
759 rq->current_nr_sectors);
760
761 if (!blk_special_request(rq)) {
762 /* We do not support buffer cache originated requests. */
763 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
764 "request queue (%d)\n", drive->name, rq->cmd_type);
765 if (blk_fs_request(rq) == 0 && rq->errors == 0)
766 rq->errors = -EIO;
767 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
768 return ide_stopped;
769 }
770
771 /* Retry a failed packet command */
772 if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
773 pc = drive->failed_pc;
774 goto out;
775 }
776
777 if (postponed_rq != NULL)
778 if (rq != postponed_rq) {
779 printk(KERN_ERR "ide-tape: ide-tape.c bug - "
780 "Two DSC requests were queued\n");
781 drive->failed_pc = NULL;
782 rq->errors = 0;
783 ide_complete_rq(drive, 0, blk_rq_bytes(rq));
784 return ide_stopped;
785 }
786
787 tape->postponed_rq = NULL;
788
789 /*
790 * If the tape is still busy, postpone our request and service
791 * the other device meanwhile.
792 */
793 stat = hwif->tp_ops->read_status(hwif);
794
795 if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 &&
796 (rq->cmd[13] & REQ_IDETAPE_PC2) == 0)
797 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
798
799 if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
800 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
801 drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
802 }
803
804 if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) &&
805 (stat & ATA_DSC) == 0) {
806 if (postponed_rq == NULL) {
807 tape->dsc_polling_start = jiffies;
808 tape->dsc_poll_freq = tape->best_dsc_rw_freq;
809 tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
810 } else if (time_after(jiffies, tape->dsc_timeout)) {
811 printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
812 tape->name);
813 if (rq->cmd[13] & REQ_IDETAPE_PC2) {
814 idetape_media_access_finished(drive);
815 return ide_stopped;
816 } else {
817 return ide_do_reset(drive);
818 }
819 } else if (time_after(jiffies,
820 tape->dsc_polling_start +
821 IDETAPE_DSC_MA_THRESHOLD))
822 tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
823 idetape_postpone_request(drive);
824 return ide_stopped;
825 }
826 if (rq->cmd[13] & REQ_IDETAPE_READ) {
827 pc = &tape->queued_pc;
828 ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
829 goto out;
830 }
831 if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
832 pc = &tape->queued_pc;
833 ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
834 goto out;
835 }
836 if (rq->cmd[13] & REQ_IDETAPE_PC1) {
837 pc = (struct ide_atapi_pc *) rq->buffer;
838 rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
839 rq->cmd[13] |= REQ_IDETAPE_PC2;
840 goto out;
841 }
842 if (rq->cmd[13] & REQ_IDETAPE_PC2) {
843 idetape_media_access_finished(drive);
844 return ide_stopped;
845 }
846 BUG();
847
848 out:
849 memset(&cmd, 0, sizeof(cmd));
850
851 if (rq_data_dir(rq))
852 cmd.tf_flags |= IDE_TFLAG_WRITE;
853
854 cmd.rq = rq;
855
856 return ide_tape_issue_pc(drive, &cmd, pc);
857 }
858
859 /*
860 * The function below uses __get_free_pages to allocate a data buffer of size
861 * tape->buffer_size (or a bit more). We attempt to combine sequential pages as
862 * much as possible.
863 *
864 * It returns a pointer to the newly allocated buffer, or NULL in case of
865 * failure.
866 */
867 static struct idetape_bh *ide_tape_kmalloc_buffer(idetape_tape_t *tape,
868 int full, int clear)
869 {
870 struct idetape_bh *prev_bh, *bh, *merge_bh;
871 int pages = tape->pages_per_buffer;
872 unsigned int order, b_allocd;
873 char *b_data = NULL;
874
875 merge_bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
876 bh = merge_bh;
877 if (bh == NULL)
878 goto abort;
879
880 order = fls(pages) - 1;
881 bh->b_data = (char *) __get_free_pages(GFP_KERNEL, order);
882 if (!bh->b_data)
883 goto abort;
884 b_allocd = (1 << order) * PAGE_SIZE;
885 pages &= (order-1);
886
887 if (clear)
888 memset(bh->b_data, 0, b_allocd);
889 bh->b_reqnext = NULL;
890 bh->b_size = b_allocd;
891 atomic_set(&bh->b_count, full ? bh->b_size : 0);
892
893 while (pages) {
894 order = fls(pages) - 1;
895 b_data = (char *) __get_free_pages(GFP_KERNEL, order);
896 if (!b_data)
897 goto abort;
898 b_allocd = (1 << order) * PAGE_SIZE;
899
900 if (clear)
901 memset(b_data, 0, b_allocd);
902
903 /* newly allocated page frames below buffer header or ...*/
904 if (bh->b_data == b_data + b_allocd) {
905 bh->b_size += b_allocd;
906 bh->b_data -= b_allocd;
907 if (full)
908 atomic_add(b_allocd, &bh->b_count);
909 continue;
910 }
911 /* they are above the header */
912 if (b_data == bh->b_data + bh->b_size) {
913 bh->b_size += b_allocd;
914 if (full)
915 atomic_add(b_allocd, &bh->b_count);
916 continue;
917 }
918 prev_bh = bh;
919 bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
920 if (!bh) {
921 free_pages((unsigned long) b_data, order);
922 goto abort;
923 }
924 bh->b_reqnext = NULL;
925 bh->b_data = b_data;
926 bh->b_size = b_allocd;
927 atomic_set(&bh->b_count, full ? bh->b_size : 0);
928 prev_bh->b_reqnext = bh;
929
930 pages &= (order-1);
931 }
932
933 bh->b_size -= tape->excess_bh_size;
934 if (full)
935 atomic_sub(tape->excess_bh_size, &bh->b_count);
936 return merge_bh;
937 abort:
938 ide_tape_kfree_buffer(tape);
939 return NULL;
940 }
941
942 static int idetape_copy_stage_from_user(idetape_tape_t *tape,
943 const char __user *buf, int n)
944 {
945 struct idetape_bh *bh = tape->bh;
946 int count;
947 int ret = 0;
948
949 while (n) {
950 if (bh == NULL) {
951 printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
952 __func__);
953 return 1;
954 }
955 count = min((unsigned int)
956 (bh->b_size - atomic_read(&bh->b_count)),
957 (unsigned int)n);
958 if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf,
959 count))
960 ret = 1;
961 n -= count;
962 atomic_add(count, &bh->b_count);
963 buf += count;
964 if (atomic_read(&bh->b_count) == bh->b_size) {
965 bh = bh->b_reqnext;
966 if (bh)
967 atomic_set(&bh->b_count, 0);
968 }
969 }
970 tape->bh = bh;
971 return ret;
972 }
973
974 static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf,
975 int n)
976 {
977 struct idetape_bh *bh = tape->bh;
978 int count;
979 int ret = 0;
980
981 while (n) {
982 if (bh == NULL) {
983 printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
984 __func__);
985 return 1;
986 }
987 count = min(tape->b_count, n);
988 if (copy_to_user(buf, tape->b_data, count))
989 ret = 1;
990 n -= count;
991 tape->b_data += count;
992 tape->b_count -= count;
993 buf += count;
994 if (!tape->b_count) {
995 bh = bh->b_reqnext;
996 tape->bh = bh;
997 if (bh) {
998 tape->b_data = bh->b_data;
999 tape->b_count = atomic_read(&bh->b_count);
1000 }
1001 }
1002 }
1003 return ret;
1004 }
1005
1006 static void idetape_init_merge_buffer(idetape_tape_t *tape)
1007 {
1008 struct idetape_bh *bh = tape->merge_bh;
1009 tape->bh = tape->merge_bh;
1010
1011 if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1012 atomic_set(&bh->b_count, 0);
1013 else {
1014 tape->b_data = bh->b_data;
1015 tape->b_count = atomic_read(&bh->b_count);
1016 }
1017 }
1018
1019 /*
1020 * Write a filemark if write_filemark=1. Flush the device buffers without
1021 * writing a filemark otherwise.
1022 */
1023 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
1024 struct ide_atapi_pc *pc, int write_filemark)
1025 {
1026 ide_init_pc(pc);
1027 pc->c[0] = WRITE_FILEMARKS;
1028 pc->c[4] = write_filemark;
1029 pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1030 }
1031
1032 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
1033 {
1034 idetape_tape_t *tape = drive->driver_data;
1035 struct gendisk *disk = tape->disk;
1036 int load_attempted = 0;
1037
1038 /* Wait for the tape to become ready */
1039 set_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1040 timeout += jiffies;
1041 while (time_before(jiffies, timeout)) {
1042 if (ide_do_test_unit_ready(drive, disk) == 0)
1043 return 0;
1044 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
1045 || (tape->asc == 0x3A)) {
1046 /* no media */
1047 if (load_attempted)
1048 return -ENOMEDIUM;
1049 ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1050 load_attempted = 1;
1051 /* not about to be ready */
1052 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
1053 (tape->ascq == 1 || tape->ascq == 8)))
1054 return -EIO;
1055 msleep(100);
1056 }
1057 return -EIO;
1058 }
1059
1060 static int idetape_flush_tape_buffers(ide_drive_t *drive)
1061 {
1062 struct ide_tape_obj *tape = drive->driver_data;
1063 struct ide_atapi_pc pc;
1064 int rc;
1065
1066 idetape_create_write_filemark_cmd(drive, &pc, 0);
1067 rc = ide_queue_pc_tail(drive, tape->disk, &pc);
1068 if (rc)
1069 return rc;
1070 idetape_wait_ready(drive, 60 * 5 * HZ);
1071 return 0;
1072 }
1073
1074 static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc)
1075 {
1076 ide_init_pc(pc);
1077 pc->c[0] = READ_POSITION;
1078 pc->req_xfer = 20;
1079 }
1080
1081 static int idetape_read_position(ide_drive_t *drive)
1082 {
1083 idetape_tape_t *tape = drive->driver_data;
1084 struct ide_atapi_pc pc;
1085 int position;
1086
1087 debug_log(DBG_PROCS, "Enter %s\n", __func__);
1088
1089 idetape_create_read_position_cmd(&pc);
1090 if (ide_queue_pc_tail(drive, tape->disk, &pc))
1091 return -1;
1092 position = tape->first_frame;
1093 return position;
1094 }
1095
1096 static void idetape_create_locate_cmd(ide_drive_t *drive,
1097 struct ide_atapi_pc *pc,
1098 unsigned int block, u8 partition, int skip)
1099 {
1100 ide_init_pc(pc);
1101 pc->c[0] = POSITION_TO_ELEMENT;
1102 pc->c[1] = 2;
1103 put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
1104 pc->c[8] = partition;
1105 pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1106 }
1107
1108 static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
1109 {
1110 idetape_tape_t *tape = drive->driver_data;
1111
1112 if (tape->chrdev_dir != IDETAPE_DIR_READ)
1113 return;
1114
1115 clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags);
1116 tape->merge_bh_size = 0;
1117 if (tape->merge_bh != NULL) {
1118 ide_tape_kfree_buffer(tape);
1119 tape->merge_bh = NULL;
1120 }
1121
1122 tape->chrdev_dir = IDETAPE_DIR_NONE;
1123 }
1124
1125 /*
1126 * Position the tape to the requested block using the LOCATE packet command.
1127 * A READ POSITION command is then issued to check where we are positioned. Like
1128 * all higher level operations, we queue the commands at the tail of the request
1129 * queue and wait for their completion.
1130 */
1131 static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
1132 u8 partition, int skip)
1133 {
1134 idetape_tape_t *tape = drive->driver_data;
1135 struct gendisk *disk = tape->disk;
1136 int retval;
1137 struct ide_atapi_pc pc;
1138
1139 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1140 __ide_tape_discard_merge_buffer(drive);
1141 idetape_wait_ready(drive, 60 * 5 * HZ);
1142 idetape_create_locate_cmd(drive, &pc, block, partition, skip);
1143 retval = ide_queue_pc_tail(drive, disk, &pc);
1144 if (retval)
1145 return (retval);
1146
1147 idetape_create_read_position_cmd(&pc);
1148 return ide_queue_pc_tail(drive, disk, &pc);
1149 }
1150
1151 static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
1152 int restore_position)
1153 {
1154 idetape_tape_t *tape = drive->driver_data;
1155 int seek, position;
1156
1157 __ide_tape_discard_merge_buffer(drive);
1158 if (restore_position) {
1159 position = idetape_read_position(drive);
1160 seek = position > 0 ? position : 0;
1161 if (idetape_position_tape(drive, seek, 0, 0)) {
1162 printk(KERN_INFO "ide-tape: %s: position_tape failed in"
1163 " %s\n", tape->name, __func__);
1164 return;
1165 }
1166 }
1167 }
1168
1169 /*
1170 * Generate a read/write request for the block device interface and wait for it
1171 * to be serviced.
1172 */
1173 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks,
1174 struct idetape_bh *bh)
1175 {
1176 idetape_tape_t *tape = drive->driver_data;
1177 struct request *rq;
1178 int ret, errors;
1179
1180 debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
1181
1182 rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
1183 rq->cmd_type = REQ_TYPE_SPECIAL;
1184 rq->cmd[13] = cmd;
1185 rq->rq_disk = tape->disk;
1186 rq->special = (void *)bh;
1187 rq->sector = tape->first_frame;
1188 rq->nr_sectors = blocks;
1189 rq->current_nr_sectors = blocks;
1190 blk_execute_rq(drive->queue, tape->disk, rq, 0);
1191
1192 errors = rq->errors;
1193 ret = tape->blk_size * (blocks - rq->current_nr_sectors);
1194 blk_put_request(rq);
1195
1196 if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
1197 return 0;
1198
1199 if (tape->merge_bh)
1200 idetape_init_merge_buffer(tape);
1201 if (errors == IDE_DRV_ERROR_GENERAL)
1202 return -EIO;
1203 return ret;
1204 }
1205
1206 static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
1207 {
1208 ide_init_pc(pc);
1209 pc->c[0] = INQUIRY;
1210 pc->c[4] = 254;
1211 pc->req_xfer = 254;
1212 }
1213
1214 static void idetape_create_rewind_cmd(ide_drive_t *drive,
1215 struct ide_atapi_pc *pc)
1216 {
1217 ide_init_pc(pc);
1218 pc->c[0] = REZERO_UNIT;
1219 pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1220 }
1221
1222 static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
1223 {
1224 ide_init_pc(pc);
1225 pc->c[0] = ERASE;
1226 pc->c[1] = 1;
1227 pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1228 }
1229
1230 static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
1231 {
1232 ide_init_pc(pc);
1233 pc->c[0] = SPACE;
1234 put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
1235 pc->c[1] = cmd;
1236 pc->flags |= PC_FLAG_WAIT_FOR_DSC;
1237 }
1238
1239 /* Queue up a character device originated write request. */
1240 static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks)
1241 {
1242 idetape_tape_t *tape = drive->driver_data;
1243
1244 debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1245
1246 return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
1247 blocks, tape->merge_bh);
1248 }
1249
1250 static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
1251 {
1252 idetape_tape_t *tape = drive->driver_data;
1253 int blocks, min;
1254 struct idetape_bh *bh;
1255
1256 if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
1257 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
1258 " but we are not writing.\n");
1259 return;
1260 }
1261 if (tape->merge_bh_size > tape->buffer_size) {
1262 printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
1263 tape->merge_bh_size = tape->buffer_size;
1264 }
1265 if (tape->merge_bh_size) {
1266 blocks = tape->merge_bh_size / tape->blk_size;
1267 if (tape->merge_bh_size % tape->blk_size) {
1268 unsigned int i;
1269
1270 blocks++;
1271 i = tape->blk_size - tape->merge_bh_size %
1272 tape->blk_size;
1273 bh = tape->bh->b_reqnext;
1274 while (bh) {
1275 atomic_set(&bh->b_count, 0);
1276 bh = bh->b_reqnext;
1277 }
1278 bh = tape->bh;
1279 while (i) {
1280 if (bh == NULL) {
1281 printk(KERN_INFO "ide-tape: bug,"
1282 " bh NULL\n");
1283 break;
1284 }
1285 min = min(i, (unsigned int)(bh->b_size -
1286 atomic_read(&bh->b_count)));
1287 memset(bh->b_data + atomic_read(&bh->b_count),
1288 0, min);
1289 atomic_add(min, &bh->b_count);
1290 i -= min;
1291 bh = bh->b_reqnext;
1292 }
1293 }
1294 (void) idetape_add_chrdev_write_request(drive, blocks);
1295 tape->merge_bh_size = 0;
1296 }
1297 if (tape->merge_bh != NULL) {
1298 ide_tape_kfree_buffer(tape);
1299 tape->merge_bh = NULL;
1300 }
1301 tape->chrdev_dir = IDETAPE_DIR_NONE;
1302 }
1303
1304 static int idetape_init_read(ide_drive_t *drive)
1305 {
1306 idetape_tape_t *tape = drive->driver_data;
1307 int bytes_read;
1308
1309 /* Initialize read operation */
1310 if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1311 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1312 ide_tape_flush_merge_buffer(drive);
1313 idetape_flush_tape_buffers(drive);
1314 }
1315 if (tape->merge_bh || tape->merge_bh_size) {
1316 printk(KERN_ERR "ide-tape: merge_bh_size should be"
1317 " 0 now\n");
1318 tape->merge_bh_size = 0;
1319 }
1320 tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
1321 if (!tape->merge_bh)
1322 return -ENOMEM;
1323 tape->chrdev_dir = IDETAPE_DIR_READ;
1324
1325 /*
1326 * Issue a read 0 command to ensure that DSC handshake is
1327 * switched from completion mode to buffer available mode.
1328 * No point in issuing this if DSC overlap isn't supported, some
1329 * drives (Seagate STT3401A) will return an error.
1330 */
1331 if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1332 bytes_read = idetape_queue_rw_tail(drive,
1333 REQ_IDETAPE_READ, 0,
1334 tape->merge_bh);
1335 if (bytes_read < 0) {
1336 ide_tape_kfree_buffer(tape);
1337 tape->merge_bh = NULL;
1338 tape->chrdev_dir = IDETAPE_DIR_NONE;
1339 return bytes_read;
1340 }
1341 }
1342 }
1343
1344 return 0;
1345 }
1346
1347 /* called from idetape_chrdev_read() to service a chrdev read request. */
1348 static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
1349 {
1350 idetape_tape_t *tape = drive->driver_data;
1351
1352 debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks);
1353
1354 /* If we are at a filemark, return a read length of 0 */
1355 if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1356 return 0;
1357
1358 idetape_init_read(drive);
1359
1360 return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
1361 tape->merge_bh);
1362 }
1363
1364 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
1365 {
1366 idetape_tape_t *tape = drive->driver_data;
1367 struct idetape_bh *bh;
1368 int blocks;
1369
1370 while (bcount) {
1371 unsigned int count;
1372
1373 bh = tape->merge_bh;
1374 count = min(tape->buffer_size, bcount);
1375 bcount -= count;
1376 blocks = count / tape->blk_size;
1377 while (count) {
1378 atomic_set(&bh->b_count,
1379 min(count, (unsigned int)bh->b_size));
1380 memset(bh->b_data, 0, atomic_read(&bh->b_count));
1381 count -= atomic_read(&bh->b_count);
1382 bh = bh->b_reqnext;
1383 }
1384 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks,
1385 tape->merge_bh);
1386 }
1387 }
1388
1389 /*
1390 * Rewinds the tape to the Beginning Of the current Partition (BOP). We
1391 * currently support only one partition.
1392 */
1393 static int idetape_rewind_tape(ide_drive_t *drive)
1394 {
1395 struct ide_tape_obj *tape = drive->driver_data;
1396 struct gendisk *disk = tape->disk;
1397 int retval;
1398 struct ide_atapi_pc pc;
1399
1400 debug_log(DBG_SENSE, "Enter %s\n", __func__);
1401
1402 idetape_create_rewind_cmd(drive, &pc);
1403 retval = ide_queue_pc_tail(drive, disk, &pc);
1404 if (retval)
1405 return retval;
1406
1407 idetape_create_read_position_cmd(&pc);
1408 retval = ide_queue_pc_tail(drive, disk, &pc);
1409 if (retval)
1410 return retval;
1411 return 0;
1412 }
1413
1414 /* mtio.h compatible commands should be issued to the chrdev interface. */
1415 static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
1416 unsigned long arg)
1417 {
1418 idetape_tape_t *tape = drive->driver_data;
1419 void __user *argp = (void __user *)arg;
1420
1421 struct idetape_config {
1422 int dsc_rw_frequency;
1423 int dsc_media_access_frequency;
1424 int nr_stages;
1425 } config;
1426
1427 debug_log(DBG_PROCS, "Enter %s\n", __func__);
1428
1429 switch (cmd) {
1430 case 0x0340:
1431 if (copy_from_user(&config, argp, sizeof(config)))
1432 return -EFAULT;
1433 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
1434 break;
1435 case 0x0350:
1436 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
1437 config.nr_stages = 1;
1438 if (copy_to_user(argp, &config, sizeof(config)))
1439 return -EFAULT;
1440 break;
1441 default:
1442 return -EIO;
1443 }
1444 return 0;
1445 }
1446
1447 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
1448 int mt_count)
1449 {
1450 idetape_tape_t *tape = drive->driver_data;
1451 struct gendisk *disk = tape->disk;
1452 struct ide_atapi_pc pc;
1453 int retval, count = 0;
1454 int sprev = !!(tape->caps[4] & 0x20);
1455
1456 if (mt_count == 0)
1457 return 0;
1458 if (MTBSF == mt_op || MTBSFM == mt_op) {
1459 if (!sprev)
1460 return -EIO;
1461 mt_count = -mt_count;
1462 }
1463
1464 if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1465 tape->merge_bh_size = 0;
1466 if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
1467 ++count;
1468 ide_tape_discard_merge_buffer(drive, 0);
1469 }
1470
1471 switch (mt_op) {
1472 case MTFSF:
1473 case MTBSF:
1474 idetape_create_space_cmd(&pc, mt_count - count,
1475 IDETAPE_SPACE_OVER_FILEMARK);
1476 return ide_queue_pc_tail(drive, disk, &pc);
1477 case MTFSFM:
1478 case MTBSFM:
1479 if (!sprev)
1480 return -EIO;
1481 retval = idetape_space_over_filemarks(drive, MTFSF,
1482 mt_count - count);
1483 if (retval)
1484 return retval;
1485 count = (MTBSFM == mt_op ? 1 : -1);
1486 return idetape_space_over_filemarks(drive, MTFSF, count);
1487 default:
1488 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1489 mt_op);
1490 return -EIO;
1491 }
1492 }
1493
1494 /*
1495 * Our character device read / write functions.
1496 *
1497 * The tape is optimized to maximize throughput when it is transferring an
1498 * integral number of the "continuous transfer limit", which is a parameter of
1499 * the specific tape (26kB on my particular tape, 32kB for Onstream).
1500 *
1501 * As of version 1.3 of the driver, the character device provides an abstract
1502 * continuous view of the media - any mix of block sizes (even 1 byte) on the
1503 * same backup/restore procedure is supported. The driver will internally
1504 * convert the requests to the recommended transfer unit, so that an unmatch
1505 * between the user's block size to the recommended size will only result in a
1506 * (slightly) increased driver overhead, but will no longer hit performance.
1507 * This is not applicable to Onstream.
1508 */
1509 static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
1510 size_t count, loff_t *ppos)
1511 {
1512 struct ide_tape_obj *tape = file->private_data;
1513 ide_drive_t *drive = tape->drive;
1514 ssize_t bytes_read, temp, actually_read = 0, rc;
1515 ssize_t ret = 0;
1516 u16 ctl = *(u16 *)&tape->caps[12];
1517
1518 debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1519
1520 if (tape->chrdev_dir != IDETAPE_DIR_READ) {
1521 if (test_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags))
1522 if (count > tape->blk_size &&
1523 (count % tape->blk_size) == 0)
1524 tape->user_bs_factor = count / tape->blk_size;
1525 }
1526 rc = idetape_init_read(drive);
1527 if (rc < 0)
1528 return rc;
1529 if (count == 0)
1530 return (0);
1531 if (tape->merge_bh_size) {
1532 actually_read = min((unsigned int)(tape->merge_bh_size),
1533 (unsigned int)count);
1534 if (idetape_copy_stage_to_user(tape, buf, actually_read))
1535 ret = -EFAULT;
1536 buf += actually_read;
1537 tape->merge_bh_size -= actually_read;
1538 count -= actually_read;
1539 }
1540 while (count >= tape->buffer_size) {
1541 bytes_read = idetape_add_chrdev_read_request(drive, ctl);
1542 if (bytes_read <= 0)
1543 goto finish;
1544 if (idetape_copy_stage_to_user(tape, buf, bytes_read))
1545 ret = -EFAULT;
1546 buf += bytes_read;
1547 count -= bytes_read;
1548 actually_read += bytes_read;
1549 }
1550 if (count) {
1551 bytes_read = idetape_add_chrdev_read_request(drive, ctl);
1552 if (bytes_read <= 0)
1553 goto finish;
1554 temp = min((unsigned long)count, (unsigned long)bytes_read);
1555 if (idetape_copy_stage_to_user(tape, buf, temp))
1556 ret = -EFAULT;
1557 actually_read += temp;
1558 tape->merge_bh_size = bytes_read-temp;
1559 }
1560 finish:
1561 if (!actually_read && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) {
1562 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
1563
1564 idetape_space_over_filemarks(drive, MTFSF, 1);
1565 return 0;
1566 }
1567
1568 return ret ? ret : actually_read;
1569 }
1570
1571 static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
1572 size_t count, loff_t *ppos)
1573 {
1574 struct ide_tape_obj *tape = file->private_data;
1575 ide_drive_t *drive = tape->drive;
1576 ssize_t actually_written = 0;
1577 ssize_t ret = 0;
1578 u16 ctl = *(u16 *)&tape->caps[12];
1579
1580 /* The drive is write protected. */
1581 if (tape->write_prot)
1582 return -EACCES;
1583
1584 debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
1585
1586 /* Initialize write operation */
1587 if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
1588 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1589 ide_tape_discard_merge_buffer(drive, 1);
1590 if (tape->merge_bh || tape->merge_bh_size) {
1591 printk(KERN_ERR "ide-tape: merge_bh_size "
1592 "should be 0 now\n");
1593 tape->merge_bh_size = 0;
1594 }
1595 tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
1596 if (!tape->merge_bh)
1597 return -ENOMEM;
1598 tape->chrdev_dir = IDETAPE_DIR_WRITE;
1599 idetape_init_merge_buffer(tape);
1600
1601 /*
1602 * Issue a write 0 command to ensure that DSC handshake is
1603 * switched from completion mode to buffer available mode. No
1604 * point in issuing this if DSC overlap isn't supported, some
1605 * drives (Seagate STT3401A) will return an error.
1606 */
1607 if (drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) {
1608 ssize_t retval = idetape_queue_rw_tail(drive,
1609 REQ_IDETAPE_WRITE, 0,
1610 tape->merge_bh);
1611 if (retval < 0) {
1612 ide_tape_kfree_buffer(tape);
1613 tape->merge_bh = NULL;
1614 tape->chrdev_dir = IDETAPE_DIR_NONE;
1615 return retval;
1616 }
1617 }
1618 }
1619 if (count == 0)
1620 return (0);
1621 if (tape->merge_bh_size) {
1622 if (tape->merge_bh_size >= tape->buffer_size) {
1623 printk(KERN_ERR "ide-tape: bug: merge buf too big\n");
1624 tape->merge_bh_size = 0;
1625 }
1626 actually_written = min((unsigned int)
1627 (tape->buffer_size - tape->merge_bh_size),
1628 (unsigned int)count);
1629 if (idetape_copy_stage_from_user(tape, buf, actually_written))
1630 ret = -EFAULT;
1631 buf += actually_written;
1632 tape->merge_bh_size += actually_written;
1633 count -= actually_written;
1634
1635 if (tape->merge_bh_size == tape->buffer_size) {
1636 ssize_t retval;
1637 tape->merge_bh_size = 0;
1638 retval = idetape_add_chrdev_write_request(drive, ctl);
1639 if (retval <= 0)
1640 return (retval);
1641 }
1642 }
1643 while (count >= tape->buffer_size) {
1644 ssize_t retval;
1645 if (idetape_copy_stage_from_user(tape, buf, tape->buffer_size))
1646 ret = -EFAULT;
1647 buf += tape->buffer_size;
1648 count -= tape->buffer_size;
1649 retval = idetape_add_chrdev_write_request(drive, ctl);
1650 actually_written += tape->buffer_size;
1651 if (retval <= 0)
1652 return (retval);
1653 }
1654 if (count) {
1655 actually_written += count;
1656 if (idetape_copy_stage_from_user(tape, buf, count))
1657 ret = -EFAULT;
1658 tape->merge_bh_size += count;
1659 }
1660 return ret ? ret : actually_written;
1661 }
1662
1663 static int idetape_write_filemark(ide_drive_t *drive)
1664 {
1665 struct ide_tape_obj *tape = drive->driver_data;
1666 struct ide_atapi_pc pc;
1667
1668 /* Write a filemark */
1669 idetape_create_write_filemark_cmd(drive, &pc, 1);
1670 if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1671 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
1672 return -EIO;
1673 }
1674 return 0;
1675 }
1676
1677 /*
1678 * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
1679 * requested.
1680 *
1681 * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
1682 * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
1683 * usually not supported.
1684 *
1685 * The following commands are currently not supported:
1686 *
1687 * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
1688 * MT_ST_WRITE_THRESHOLD.
1689 */
1690 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
1691 {
1692 idetape_tape_t *tape = drive->driver_data;
1693 struct gendisk *disk = tape->disk;
1694 struct ide_atapi_pc pc;
1695 int i, retval;
1696
1697 debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
1698 mt_op, mt_count);
1699
1700 switch (mt_op) {
1701 case MTFSF:
1702 case MTFSFM:
1703 case MTBSF:
1704 case MTBSFM:
1705 if (!mt_count)
1706 return 0;
1707 return idetape_space_over_filemarks(drive, mt_op, mt_count);
1708 default:
1709 break;
1710 }
1711
1712 switch (mt_op) {
1713 case MTWEOF:
1714 if (tape->write_prot)
1715 return -EACCES;
1716 ide_tape_discard_merge_buffer(drive, 1);
1717 for (i = 0; i < mt_count; i++) {
1718 retval = idetape_write_filemark(drive);
1719 if (retval)
1720 return retval;
1721 }
1722 return 0;
1723 case MTREW:
1724 ide_tape_discard_merge_buffer(drive, 0);
1725 if (idetape_rewind_tape(drive))
1726 return -EIO;
1727 return 0;
1728 case MTLOAD:
1729 ide_tape_discard_merge_buffer(drive, 0);
1730 return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK);
1731 case MTUNLOAD:
1732 case MTOFFL:
1733 /*
1734 * If door is locked, attempt to unlock before
1735 * attempting to eject.
1736 */
1737 if (tape->door_locked) {
1738 if (!ide_set_media_lock(drive, disk, 0))
1739 tape->door_locked = DOOR_UNLOCKED;
1740 }
1741 ide_tape_discard_merge_buffer(drive, 0);
1742 retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK);
1743 if (!retval)
1744 clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
1745 return retval;
1746 case MTNOP:
1747 ide_tape_discard_merge_buffer(drive, 0);
1748 return idetape_flush_tape_buffers(drive);
1749 case MTRETEN:
1750 ide_tape_discard_merge_buffer(drive, 0);
1751 return ide_do_start_stop(drive, disk,
1752 IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
1753 case MTEOM:
1754 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
1755 return ide_queue_pc_tail(drive, disk, &pc);
1756 case MTERASE:
1757 (void)idetape_rewind_tape(drive);
1758 idetape_create_erase_cmd(&pc);
1759 return ide_queue_pc_tail(drive, disk, &pc);
1760 case MTSETBLK:
1761 if (mt_count) {
1762 if (mt_count < tape->blk_size ||
1763 mt_count % tape->blk_size)
1764 return -EIO;
1765 tape->user_bs_factor = mt_count / tape->blk_size;
1766 clear_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1767 } else
1768 set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
1769 return 0;
1770 case MTSEEK:
1771 ide_tape_discard_merge_buffer(drive, 0);
1772 return idetape_position_tape(drive,
1773 mt_count * tape->user_bs_factor, tape->partition, 0);
1774 case MTSETPART:
1775 ide_tape_discard_merge_buffer(drive, 0);
1776 return idetape_position_tape(drive, 0, mt_count, 0);
1777 case MTFSR:
1778 case MTBSR:
1779 case MTLOCK:
1780 retval = ide_set_media_lock(drive, disk, 1);
1781 if (retval)
1782 return retval;
1783 tape->door_locked = DOOR_EXPLICITLY_LOCKED;
1784 return 0;
1785 case MTUNLOCK:
1786 retval = ide_set_media_lock(drive, disk, 0);
1787 if (retval)
1788 return retval;
1789 tape->door_locked = DOOR_UNLOCKED;
1790 return 0;
1791 default:
1792 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
1793 mt_op);
1794 return -EIO;
1795 }
1796 }
1797
1798 /*
1799 * Our character device ioctls. General mtio.h magnetic io commands are
1800 * supported here, and not in the corresponding block interface. Our own
1801 * ide-tape ioctls are supported on both interfaces.
1802 */
1803 static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
1804 unsigned int cmd, unsigned long arg)
1805 {
1806 struct ide_tape_obj *tape = file->private_data;
1807 ide_drive_t *drive = tape->drive;
1808 struct mtop mtop;
1809 struct mtget mtget;
1810 struct mtpos mtpos;
1811 int block_offset = 0, position = tape->first_frame;
1812 void __user *argp = (void __user *)arg;
1813
1814 debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
1815
1816 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
1817 ide_tape_flush_merge_buffer(drive);
1818 idetape_flush_tape_buffers(drive);
1819 }
1820 if (cmd == MTIOCGET || cmd == MTIOCPOS) {
1821 block_offset = tape->merge_bh_size /
1822 (tape->blk_size * tape->user_bs_factor);
1823 position = idetape_read_position(drive);
1824 if (position < 0)
1825 return -EIO;
1826 }
1827 switch (cmd) {
1828 case MTIOCTOP:
1829 if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
1830 return -EFAULT;
1831 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
1832 case MTIOCGET:
1833 memset(&mtget, 0, sizeof(struct mtget));
1834 mtget.mt_type = MT_ISSCSI2;
1835 mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
1836 mtget.mt_dsreg =
1837 ((tape->blk_size * tape->user_bs_factor)
1838 << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
1839
1840 if (tape->drv_write_prot)
1841 mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
1842
1843 if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
1844 return -EFAULT;
1845 return 0;
1846 case MTIOCPOS:
1847 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
1848 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
1849 return -EFAULT;
1850 return 0;
1851 default:
1852 if (tape->chrdev_dir == IDETAPE_DIR_READ)
1853 ide_tape_discard_merge_buffer(drive, 1);
1854 return idetape_blkdev_ioctl(drive, cmd, arg);
1855 }
1856 }
1857
1858 /*
1859 * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
1860 * block size with the reported value.
1861 */
1862 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
1863 {
1864 idetape_tape_t *tape = drive->driver_data;
1865 struct ide_atapi_pc pc;
1866
1867 idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
1868 if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
1869 printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
1870 if (tape->blk_size == 0) {
1871 printk(KERN_WARNING "ide-tape: Cannot deal with zero "
1872 "block size, assuming 32k\n");
1873 tape->blk_size = 32768;
1874 }
1875 return;
1876 }
1877 tape->blk_size = (pc.buf[4 + 5] << 16) +
1878 (pc.buf[4 + 6] << 8) +
1879 pc.buf[4 + 7];
1880 tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7;
1881 }
1882
1883 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
1884 {
1885 unsigned int minor = iminor(inode), i = minor & ~0xc0;
1886 ide_drive_t *drive;
1887 idetape_tape_t *tape;
1888 int retval;
1889
1890 if (i >= MAX_HWIFS * MAX_DRIVES)
1891 return -ENXIO;
1892
1893 lock_kernel();
1894 tape = ide_tape_chrdev_get(i);
1895 if (!tape) {
1896 unlock_kernel();
1897 return -ENXIO;
1898 }
1899
1900 debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1901
1902 /*
1903 * We really want to do nonseekable_open(inode, filp); here, but some
1904 * versions of tar incorrectly call lseek on tapes and bail out if that
1905 * fails. So we disallow pread() and pwrite(), but permit lseeks.
1906 */
1907 filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1908
1909 drive = tape->drive;
1910
1911 filp->private_data = tape;
1912
1913 if (test_and_set_bit(IDE_AFLAG_BUSY, &drive->atapi_flags)) {
1914 retval = -EBUSY;
1915 goto out_put_tape;
1916 }
1917
1918 retval = idetape_wait_ready(drive, 60 * HZ);
1919 if (retval) {
1920 clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1921 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
1922 goto out_put_tape;
1923 }
1924
1925 idetape_read_position(drive);
1926 if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags))
1927 (void)idetape_rewind_tape(drive);
1928
1929 /* Read block size and write protect status from drive. */
1930 ide_tape_get_bsize_from_bdesc(drive);
1931
1932 /* Set write protect flag if device is opened as read-only. */
1933 if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
1934 tape->write_prot = 1;
1935 else
1936 tape->write_prot = tape->drv_write_prot;
1937
1938 /* Make sure drive isn't write protected if user wants to write. */
1939 if (tape->write_prot) {
1940 if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
1941 (filp->f_flags & O_ACCMODE) == O_RDWR) {
1942 clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
1943 retval = -EROFS;
1944 goto out_put_tape;
1945 }
1946 }
1947
1948 /* Lock the tape drive door so user can't eject. */
1949 if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
1950 if (!ide_set_media_lock(drive, tape->disk, 1)) {
1951 if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
1952 tape->door_locked = DOOR_LOCKED;
1953 }
1954 }
1955 unlock_kernel();
1956 return 0;
1957
1958 out_put_tape:
1959 ide_tape_put(tape);
1960 unlock_kernel();
1961 return retval;
1962 }
1963
1964 static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
1965 {
1966 idetape_tape_t *tape = drive->driver_data;
1967
1968 ide_tape_flush_merge_buffer(drive);
1969 tape->merge_bh = ide_tape_kmalloc_buffer(tape, 1, 0);
1970 if (tape->merge_bh != NULL) {
1971 idetape_pad_zeros(drive, tape->blk_size *
1972 (tape->user_bs_factor - 1));
1973 ide_tape_kfree_buffer(tape);
1974 tape->merge_bh = NULL;
1975 }
1976 idetape_write_filemark(drive);
1977 idetape_flush_tape_buffers(drive);
1978 idetape_flush_tape_buffers(drive);
1979 }
1980
1981 static int idetape_chrdev_release(struct inode *inode, struct file *filp)
1982 {
1983 struct ide_tape_obj *tape = filp->private_data;
1984 ide_drive_t *drive = tape->drive;
1985 unsigned int minor = iminor(inode);
1986
1987 lock_kernel();
1988 tape = drive->driver_data;
1989
1990 debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
1991
1992 if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
1993 idetape_write_release(drive, minor);
1994 if (tape->chrdev_dir == IDETAPE_DIR_READ) {
1995 if (minor < 128)
1996 ide_tape_discard_merge_buffer(drive, 1);
1997 }
1998
1999 if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags))
2000 (void) idetape_rewind_tape(drive);
2001 if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
2002 if (tape->door_locked == DOOR_LOCKED) {
2003 if (!ide_set_media_lock(drive, tape->disk, 0))
2004 tape->door_locked = DOOR_UNLOCKED;
2005 }
2006 }
2007 clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
2008 ide_tape_put(tape);
2009 unlock_kernel();
2010 return 0;
2011 }
2012
2013 static void idetape_get_inquiry_results(ide_drive_t *drive)
2014 {
2015 idetape_tape_t *tape = drive->driver_data;
2016 struct ide_atapi_pc pc;
2017 u8 pc_buf[256];
2018 char fw_rev[4], vendor_id[8], product_id[16];
2019
2020 idetape_create_inquiry_cmd(&pc);
2021 pc.buf = &pc_buf[0];
2022 pc.buf_size = sizeof(pc_buf);
2023
2024 if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
2025 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
2026 tape->name);
2027 return;
2028 }
2029 memcpy(vendor_id, &pc.buf[8], 8);
2030 memcpy(product_id, &pc.buf[16], 16);
2031 memcpy(fw_rev, &pc.buf[32], 4);
2032
2033 ide_fixstring(vendor_id, 8, 0);
2034 ide_fixstring(product_id, 16, 0);
2035 ide_fixstring(fw_rev, 4, 0);
2036
2037 printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\n",
2038 drive->name, tape->name, vendor_id, product_id, fw_rev);
2039 }
2040
2041 /*
2042 * Ask the tape about its various parameters. In particular, we will adjust our
2043 * data transfer buffer size to the recommended value as returned by the tape.
2044 */
2045 static void idetape_get_mode_sense_results(ide_drive_t *drive)
2046 {
2047 idetape_tape_t *tape = drive->driver_data;
2048 struct ide_atapi_pc pc;
2049 u8 *caps;
2050 u8 speed, max_speed;
2051
2052 idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
2053 if (ide_queue_pc_tail(drive, tape->disk, &pc)) {
2054 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
2055 " some default values\n");
2056 tape->blk_size = 512;
2057 put_unaligned(52, (u16 *)&tape->caps[12]);
2058 put_unaligned(540, (u16 *)&tape->caps[14]);
2059 put_unaligned(6*52, (u16 *)&tape->caps[16]);
2060 return;
2061 }
2062 caps = pc.buf + 4 + pc.buf[3];
2063
2064 /* convert to host order and save for later use */
2065 speed = be16_to_cpup((__be16 *)&caps[14]);
2066 max_speed = be16_to_cpup((__be16 *)&caps[8]);
2067
2068 *(u16 *)&caps[8] = max_speed;
2069 *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
2070 *(u16 *)&caps[14] = speed;
2071 *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
2072
2073 if (!speed) {
2074 printk(KERN_INFO "ide-tape: %s: invalid tape speed "
2075 "(assuming 650KB/sec)\n", drive->name);
2076 *(u16 *)&caps[14] = 650;
2077 }
2078 if (!max_speed) {
2079 printk(KERN_INFO "ide-tape: %s: invalid max_speed "
2080 "(assuming 650KB/sec)\n", drive->name);
2081 *(u16 *)&caps[8] = 650;
2082 }
2083
2084 memcpy(&tape->caps, caps, 20);
2085
2086 /* device lacks locking support according to capabilities page */
2087 if ((caps[6] & 1) == 0)
2088 drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;
2089
2090 if (caps[7] & 0x02)
2091 tape->blk_size = 512;
2092 else if (caps[7] & 0x04)
2093 tape->blk_size = 1024;
2094 }
2095
2096 #ifdef CONFIG_IDE_PROC_FS
2097 #define ide_tape_devset_get(name, field) \
2098 static int get_##name(ide_drive_t *drive) \
2099 { \
2100 idetape_tape_t *tape = drive->driver_data; \
2101 return tape->field; \
2102 }
2103
2104 #define ide_tape_devset_set(name, field) \
2105 static int set_##name(ide_drive_t *drive, int arg) \
2106 { \
2107 idetape_tape_t *tape = drive->driver_data; \
2108 tape->field = arg; \
2109 return 0; \
2110 }
2111
2112 #define ide_tape_devset_rw_field(_name, _field) \
2113 ide_tape_devset_get(_name, _field) \
2114 ide_tape_devset_set(_name, _field) \
2115 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name)
2116
2117 #define ide_tape_devset_r_field(_name, _field) \
2118 ide_tape_devset_get(_name, _field) \
2119 IDE_DEVSET(_name, 0, get_##_name, NULL)
2120
2121 static int mulf_tdsc(ide_drive_t *drive) { return 1000; }
2122 static int divf_tdsc(ide_drive_t *drive) { return HZ; }
2123 static int divf_buffer(ide_drive_t *drive) { return 2; }
2124 static int divf_buffer_size(ide_drive_t *drive) { return 1024; }
2125
2126 ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
2127
2128 ide_tape_devset_rw_field(debug_mask, debug_mask);
2129 ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq);
2130
2131 ide_tape_devset_r_field(avg_speed, avg_speed);
2132 ide_tape_devset_r_field(speed, caps[14]);
2133 ide_tape_devset_r_field(buffer, caps[16]);
2134 ide_tape_devset_r_field(buffer_size, buffer_size);
2135
2136 static const struct ide_proc_devset idetape_settings[] = {
2137 __IDE_PROC_DEVSET(avg_speed, 0, 0xffff, NULL, NULL),
2138 __IDE_PROC_DEVSET(buffer, 0, 0xffff, NULL, divf_buffer),
2139 __IDE_PROC_DEVSET(buffer_size, 0, 0xffff, NULL, divf_buffer_size),
2140 __IDE_PROC_DEVSET(debug_mask, 0, 0xffff, NULL, NULL),
2141 __IDE_PROC_DEVSET(dsc_overlap, 0, 1, NULL, NULL),
2142 __IDE_PROC_DEVSET(speed, 0, 0xffff, NULL, NULL),
2143 __IDE_PROC_DEVSET(tdsc, IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX,
2144 mulf_tdsc, divf_tdsc),
2145 { NULL },
2146 };
2147 #endif
2148
2149 /*
2150 * The function below is called to:
2151 *
2152 * 1. Initialize our various state variables.
2153 * 2. Ask the tape for its capabilities.
2154 * 3. Allocate a buffer which will be used for data transfer. The buffer size
2155 * is chosen based on the recommendation which we received in step 2.
2156 *
2157 * Note that at this point ide.c already assigned us an irq, so that we can
2158 * queue requests here and wait for their completion.
2159 */
2160 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
2161 {
2162 unsigned long t;
2163 int speed;
2164 int buffer_size;
2165 u16 *ctl = (u16 *)&tape->caps[12];
2166
2167 drive->pc_callback = ide_tape_callback;
2168 drive->pc_update_buffers = idetape_update_buffers;
2169 drive->pc_io_buffers = ide_tape_io_buffers;
2170
2171 drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
2172
2173 if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
2174 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
2175 tape->name);
2176 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
2177 }
2178
2179 /* Seagate Travan drives do not support DSC overlap. */
2180 if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401"))
2181 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
2182
2183 tape->minor = minor;
2184 tape->name[0] = 'h';
2185 tape->name[1] = 't';
2186 tape->name[2] = '0' + minor;
2187 tape->chrdev_dir = IDETAPE_DIR_NONE;
2188
2189 idetape_get_inquiry_results(drive);
2190 idetape_get_mode_sense_results(drive);
2191 ide_tape_get_bsize_from_bdesc(drive);
2192 tape->user_bs_factor = 1;
2193 tape->buffer_size = *ctl * tape->blk_size;
2194 while (tape->buffer_size > 0xffff) {
2195 printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
2196 *ctl /= 2;
2197 tape->buffer_size = *ctl * tape->blk_size;
2198 }
2199 buffer_size = tape->buffer_size;
2200 tape->pages_per_buffer = buffer_size / PAGE_SIZE;
2201 if (buffer_size % PAGE_SIZE) {
2202 tape->pages_per_buffer++;
2203 tape->excess_bh_size = PAGE_SIZE - buffer_size % PAGE_SIZE;
2204 }
2205
2206 /* select the "best" DSC read/write polling freq */
2207 speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
2208
2209 t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
2210
2211 /*
2212 * Ensure that the number we got makes sense; limit it within
2213 * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
2214 */
2215 tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
2216 IDETAPE_DSC_RW_MAX);
2217 printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
2218 "%lums tDSC%s\n",
2219 drive->name, tape->name, *(u16 *)&tape->caps[14],
2220 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
2221 tape->buffer_size / 1024,
2222 tape->best_dsc_rw_freq * 1000 / HZ,
2223 (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : "");
2224
2225 ide_proc_register_driver(drive, tape->driver);
2226 }
2227
2228 static void ide_tape_remove(ide_drive_t *drive)
2229 {
2230 idetape_tape_t *tape = drive->driver_data;
2231
2232 ide_proc_unregister_driver(drive, tape->driver);
2233 device_del(&tape->dev);
2234 ide_unregister_region(tape->disk);
2235
2236 mutex_lock(&idetape_ref_mutex);
2237 put_device(&tape->dev);
2238 mutex_unlock(&idetape_ref_mutex);
2239 }
2240
2241 static void ide_tape_release(struct device *dev)
2242 {
2243 struct ide_tape_obj *tape = to_ide_drv(dev, ide_tape_obj);
2244 ide_drive_t *drive = tape->drive;
2245 struct gendisk *g = tape->disk;
2246
2247 BUG_ON(tape->merge_bh_size);
2248
2249 drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
2250 drive->driver_data = NULL;
2251 device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
2252 device_destroy(idetape_sysfs_class,
2253 MKDEV(IDETAPE_MAJOR, tape->minor + 128));
2254 idetape_devs[tape->minor] = NULL;
2255 g->private_data = NULL;
2256 put_disk(g);
2257 kfree(tape);
2258 }
2259
2260 #ifdef CONFIG_IDE_PROC_FS
2261 static int proc_idetape_read_name
2262 (char *page, char **start, off_t off, int count, int *eof, void *data)
2263 {
2264 ide_drive_t *drive = (ide_drive_t *) data;
2265 idetape_tape_t *tape = drive->driver_data;
2266 char *out = page;
2267 int len;
2268
2269 len = sprintf(out, "%s\n", tape->name);
2270 PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
2271 }
2272
2273 static ide_proc_entry_t idetape_proc[] = {
2274 { "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL },
2275 { "name", S_IFREG|S_IRUGO, proc_idetape_read_name, NULL },
2276 { NULL, 0, NULL, NULL }
2277 };
2278
2279 static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive)
2280 {
2281 return idetape_proc;
2282 }
2283
2284 static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive)
2285 {
2286 return idetape_settings;
2287 }
2288 #endif
2289
2290 static int ide_tape_probe(ide_drive_t *);
2291
2292 static struct ide_driver idetape_driver = {
2293 .gen_driver = {
2294 .owner = THIS_MODULE,
2295 .name = "ide-tape",
2296 .bus = &ide_bus_type,
2297 },
2298 .probe = ide_tape_probe,
2299 .remove = ide_tape_remove,
2300 .version = IDETAPE_VERSION,
2301 .do_request = idetape_do_request,
2302 #ifdef CONFIG_IDE_PROC_FS
2303 .proc_entries = ide_tape_proc_entries,
2304 .proc_devsets = ide_tape_proc_devsets,
2305 #endif
2306 };
2307
2308 /* Our character device supporting functions, passed to register_chrdev. */
2309 static const struct file_operations idetape_fops = {
2310 .owner = THIS_MODULE,
2311 .read = idetape_chrdev_read,
2312 .write = idetape_chrdev_write,
2313 .ioctl = idetape_chrdev_ioctl,
2314 .open = idetape_chrdev_open,
2315 .release = idetape_chrdev_release,
2316 };
2317
2318 static int idetape_open(struct block_device *bdev, fmode_t mode)
2319 {
2320 struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk);
2321
2322 if (!tape)
2323 return -ENXIO;
2324
2325 return 0;
2326 }
2327
2328 static int idetape_release(struct gendisk *disk, fmode_t mode)
2329 {
2330 struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj);
2331
2332 ide_tape_put(tape);
2333 return 0;
2334 }
2335
2336 static int idetape_ioctl(struct block_device *bdev, fmode_t mode,
2337 unsigned int cmd, unsigned long arg)
2338 {
2339 struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj);
2340 ide_drive_t *drive = tape->drive;
2341 int err = generic_ide_ioctl(drive, bdev, cmd, arg);
2342 if (err == -EINVAL)
2343 err = idetape_blkdev_ioctl(drive, cmd, arg);
2344 return err;
2345 }
2346
2347 static struct block_device_operations idetape_block_ops = {
2348 .owner = THIS_MODULE,
2349 .open = idetape_open,
2350 .release = idetape_release,
2351 .locked_ioctl = idetape_ioctl,
2352 };
2353
2354 static int ide_tape_probe(ide_drive_t *drive)
2355 {
2356 idetape_tape_t *tape;
2357 struct gendisk *g;
2358 int minor;
2359
2360 if (!strstr("ide-tape", drive->driver_req))
2361 goto failed;
2362
2363 if (drive->media != ide_tape)
2364 goto failed;
2365
2366 if ((drive->dev_flags & IDE_DFLAG_ID_READ) &&
2367 ide_check_atapi_device(drive, DRV_NAME) == 0) {
2368 printk(KERN_ERR "ide-tape: %s: not supported by this version of"
2369 " the driver\n", drive->name);
2370 goto failed;
2371 }
2372 tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
2373 if (tape == NULL) {
2374 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
2375 drive->name);
2376 goto failed;
2377 }
2378
2379 g = alloc_disk(1 << PARTN_BITS);
2380 if (!g)
2381 goto out_free_tape;
2382
2383 ide_init_disk(g, drive);
2384
2385 tape->dev.parent = &drive->gendev;
2386 tape->dev.release = ide_tape_release;
2387 dev_set_name(&tape->dev, dev_name(&drive->gendev));
2388
2389 if (device_register(&tape->dev))
2390 goto out_free_disk;
2391
2392 tape->drive = drive;
2393 tape->driver = &idetape_driver;
2394 tape->disk = g;
2395
2396 g->private_data = &tape->driver;
2397
2398 drive->driver_data = tape;
2399
2400 mutex_lock(&idetape_ref_mutex);
2401 for (minor = 0; idetape_devs[minor]; minor++)
2402 ;
2403 idetape_devs[minor] = tape;
2404 mutex_unlock(&idetape_ref_mutex);
2405
2406 idetape_setup(drive, tape, minor);
2407
2408 device_create(idetape_sysfs_class, &drive->gendev,
2409 MKDEV(IDETAPE_MAJOR, minor), NULL, "%s", tape->name);
2410 device_create(idetape_sysfs_class, &drive->gendev,
2411 MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
2412 "n%s", tape->name);
2413
2414 g->fops = &idetape_block_ops;
2415 ide_register_region(g);
2416
2417 return 0;
2418
2419 out_free_disk:
2420 put_disk(g);
2421 out_free_tape:
2422 kfree(tape);
2423 failed:
2424 return -ENODEV;
2425 }
2426
2427 static void __exit idetape_exit(void)
2428 {
2429 driver_unregister(&idetape_driver.gen_driver);
2430 class_destroy(idetape_sysfs_class);
2431 unregister_chrdev(IDETAPE_MAJOR, "ht");
2432 }
2433
2434 static int __init idetape_init(void)
2435 {
2436 int error = 1;
2437 idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
2438 if (IS_ERR(idetape_sysfs_class)) {
2439 idetape_sysfs_class = NULL;
2440 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
2441 error = -EBUSY;
2442 goto out;
2443 }
2444
2445 if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
2446 printk(KERN_ERR "ide-tape: Failed to register chrdev"
2447 " interface\n");
2448 error = -EBUSY;
2449 goto out_free_class;
2450 }
2451
2452 error = driver_register(&idetape_driver.gen_driver);
2453 if (error)
2454 goto out_free_driver;
2455
2456 return 0;
2457
2458 out_free_driver:
2459 driver_unregister(&idetape_driver.gen_driver);
2460 out_free_class:
2461 class_destroy(idetape_sysfs_class);
2462 out:
2463 return error;
2464 }
2465
2466 MODULE_ALIAS("ide:*m-tape*");
2467 module_init(idetape_init);
2468 module_exit(idetape_exit);
2469 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
2470 MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
2471 MODULE_LICENSE("GPL");
linux 2.6 git repository for openrd