1 /*
2 * linux/drivers/ide/ide-tape.c Version 1.19 Nov, 2003
3 *
4 * Copyright (C) 1995 - 1999 Gadi Oxman <gadio@netvision.net.il>
5 *
6 * $Header$
7 *
8 * This driver was constructed as a student project in the software laboratory
9 * of the faculty of electrical engineering in the Technion - Israel's
10 * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
11 *
12 * It is hereby placed under the terms of the GNU general public license.
13 * (See linux/COPYING).
14 */
15
16 /*
17 * IDE ATAPI streaming tape driver.
18 *
19 * This driver is a part of the Linux ide driver and works in co-operation
20 * with linux/drivers/block/ide.c.
21 *
22 * The driver, in co-operation with ide.c, basically traverses the
23 * request-list for the block device interface. The character device
24 * interface, on the other hand, creates new requests, adds them
25 * to the request-list of the block device, and waits for their completion.
26 *
27 * Pipelined operation mode is now supported on both reads and writes.
28 *
29 * The block device major and minor numbers are determined from the
30 * tape's relative position in the ide interfaces, as explained in ide.c.
31 *
32 * The character device interface consists of the following devices:
33 *
34 * ht0 major 37, minor 0 first IDE tape, rewind on close.
35 * ht1 major 37, minor 1 second IDE tape, rewind on close.
36 * ...
37 * nht0 major 37, minor 128 first IDE tape, no rewind on close.
38 * nht1 major 37, minor 129 second IDE tape, no rewind on close.
39 * ...
40 *
41 * Run linux/scripts/MAKEDEV.ide to create the above entries.
42 *
43 * The general magnetic tape commands compatible interface, as defined by
44 * include/linux/mtio.h, is accessible through the character device.
45 *
46 * General ide driver configuration options, such as the interrupt-unmask
47 * flag, can be configured by issuing an ioctl to the block device interface,
48 * as any other ide device.
49 *
50 * Our own ide-tape ioctl's can be issued to either the block device or
51 * the character device interface.
52 *
53 * Maximal throughput with minimal bus load will usually be achieved in the
54 * following scenario:
55 *
56 * 1. ide-tape is operating in the pipelined operation mode.
57 * 2. No buffering is performed by the user backup program.
58 *
59 * Testing was done with a 2 GB CONNER CTMA 4000 IDE ATAPI Streaming Tape Drive.
60 *
61 * Ver 0.1 Nov 1 95 Pre-working code :-)
62 * Ver 0.2 Nov 23 95 A short backup (few megabytes) and restore procedure
63 * was successful ! (Using tar cvf ... on the block
64 * device interface).
65 * A longer backup resulted in major swapping, bad
66 * overall Linux performance and eventually failed as
67 * we received non serial read-ahead requests from the
68 * buffer cache.
69 * Ver 0.3 Nov 28 95 Long backups are now possible, thanks to the
70 * character device interface. Linux's responsiveness
71 * and performance doesn't seem to be much affected
72 * from the background backup procedure.
73 * Some general mtio.h magnetic tape operations are
74 * now supported by our character device. As a result,
75 * popular tape utilities are starting to work with
76 * ide tapes :-)
77 * The following configurations were tested:
78 * 1. An IDE ATAPI TAPE shares the same interface
79 * and irq with an IDE ATAPI CDROM.
80 * 2. An IDE ATAPI TAPE shares the same interface
81 * and irq with a normal IDE disk.
82 * Both configurations seemed to work just fine !
83 * However, to be on the safe side, it is meanwhile
84 * recommended to give the IDE TAPE its own interface
85 * and irq.
86 * The one thing which needs to be done here is to
87 * add a "request postpone" feature to ide.c,
88 * so that we won't have to wait for the tape to finish
89 * performing a long media access (DSC) request (such
90 * as a rewind) before we can access the other device
91 * on the same interface. This effect doesn't disturb
92 * normal operation most of the time because read/write
93 * requests are relatively fast, and once we are
94 * performing one tape r/w request, a lot of requests
95 * from the other device can be queued and ide.c will
96 * service all of them after this single tape request.
97 * Ver 1.0 Dec 11 95 Integrated into Linux 1.3.46 development tree.
98 * On each read / write request, we now ask the drive
99 * if we can transfer a constant number of bytes
100 * (a parameter of the drive) only to its buffers,
101 * without causing actual media access. If we can't,
102 * we just wait until we can by polling the DSC bit.
103 * This ensures that while we are not transferring
104 * more bytes than the constant referred to above, the
105 * interrupt latency will not become too high and
106 * we won't cause an interrupt timeout, as happened
107 * occasionally in the previous version.
108 * While polling for DSC, the current request is
109 * postponed and ide.c is free to handle requests from
110 * the other device. This is handled transparently to
111 * ide.c. The hwgroup locking method which was used
112 * in the previous version was removed.
113 * Use of new general features which are provided by
114 * ide.c for use with atapi devices.
115 * (Programming done by Mark Lord)
116 * Few potential bug fixes (Again, suggested by Mark)
117 * Single character device data transfers are now
118 * not limited in size, as they were before.
119 * We are asking the tape about its recommended
120 * transfer unit and send a larger data transfer
121 * as several transfers of the above size.
122 * For best results, use an integral number of this
123 * basic unit (which is shown during driver
124 * initialization). I will soon add an ioctl to get
125 * this important parameter.
126 * Our data transfer buffer is allocated on startup,
127 * rather than before each data transfer. This should
128 * ensure that we will indeed have a data buffer.
129 * Ver 1.1 Dec 14 95 Fixed random problems which occurred when the tape
130 * shared an interface with another device.
131 * (poll_for_dsc was a complete mess).
132 * Removed some old (non-active) code which had
133 * to do with supporting buffer cache originated
134 * requests.
135 * The block device interface can now be opened, so
136 * that general ide driver features like the unmask
137 * interrupts flag can be selected with an ioctl.
138 * This is the only use of the block device interface.
139 * New fast pipelined operation mode (currently only on
140 * writes). When using the pipelined mode, the
141 * throughput can potentially reach the maximum
142 * tape supported throughput, regardless of the
143 * user backup program. On my tape drive, it sometimes
144 * boosted performance by a factor of 2. Pipelined
145 * mode is enabled by default, but since it has a few
146 * downfalls as well, you may want to disable it.
147 * A short explanation of the pipelined operation mode
148 * is available below.
149 * Ver 1.2 Jan 1 96 Eliminated pipelined mode race condition.
150 * Added pipeline read mode. As a result, restores
151 * are now as fast as backups.
152 * Optimized shared interface behavior. The new behavior
153 * typically results in better IDE bus efficiency and
154 * higher tape throughput.
155 * Pre-calculation of the expected read/write request
156 * service time, based on the tape's parameters. In
157 * the pipelined operation mode, this allows us to
158 * adjust our polling frequency to a much lower value,
159 * and thus to dramatically reduce our load on Linux,
160 * without any decrease in performance.
161 * Implemented additional mtio.h operations.
162 * The recommended user block size is returned by
163 * the MTIOCGET ioctl.
164 * Additional minor changes.
165 * Ver 1.3 Feb 9 96 Fixed pipelined read mode bug which prevented the
166 * use of some block sizes during a restore procedure.
167 * The character device interface will now present a
168 * continuous view of the media - any mix of block sizes
169 * during a backup/restore procedure is supported. The
170 * driver will buffer the requests internally and
171 * convert them to the tape's recommended transfer
172 * unit, making performance almost independent of the
173 * chosen user block size.
174 * Some improvements in error recovery.
175 * By cooperating with ide-dma.c, bus mastering DMA can
176 * now sometimes be used with IDE tape drives as well.
177 * Bus mastering DMA has the potential to dramatically
178 * reduce the CPU's overhead when accessing the device,
179 * and can be enabled by using hdparm -d1 on the tape's
180 * block device interface. For more info, read the
181 * comments in ide-dma.c.
182 * Ver 1.4 Mar 13 96 Fixed serialize support.
183 * Ver 1.5 Apr 12 96 Fixed shared interface operation, broken in 1.3.85.
184 * Fixed pipelined read mode inefficiency.
185 * Fixed nasty null dereferencing bug.
186 * Ver 1.6 Aug 16 96 Fixed FPU usage in the driver.
187 * Fixed end of media bug.
188 * Ver 1.7 Sep 10 96 Minor changes for the CONNER CTT8000-A model.
189 * Ver 1.8 Sep 26 96 Attempt to find a better balance between good
190 * interactive response and high system throughput.
191 * Ver 1.9 Nov 5 96 Automatically cross encountered filemarks rather
192 * than requiring an explicit FSF command.
193 * Abort pending requests at end of media.
194 * MTTELL was sometimes returning incorrect results.
195 * Return the real block size in the MTIOCGET ioctl.
196 * Some error recovery bug fixes.
197 * Ver 1.10 Nov 5 96 Major reorganization.
198 * Reduced CPU overhead a bit by eliminating internal
199 * bounce buffers.
200 * Added module support.
201 * Added multiple tape drives support.
202 * Added partition support.
203 * Rewrote DSC handling.
204 * Some portability fixes.
205 * Removed ide-tape.h.
206 * Additional minor changes.
207 * Ver 1.11 Dec 2 96 Bug fix in previous DSC timeout handling.
208 * Use ide_stall_queue() for DSC overlap.
209 * Use the maximum speed rather than the current speed
210 * to compute the request service time.
211 * Ver 1.12 Dec 7 97 Fix random memory overwriting and/or last block data
212 * corruption, which could occur if the total number
213 * of bytes written to the tape was not an integral
214 * number of tape blocks.
215 * Add support for INTERRUPT DRQ devices.
216 * Ver 1.13 Jan 2 98 Add "speed == 0" work-around for HP COLORADO 5GB
217 * Ver 1.14 Dec 30 98 Partial fixes for the Sony/AIWA tape drives.
218 * Replace cli()/sti() with hwgroup spinlocks.
219 * Ver 1.15 Mar 25 99 Fix SMP race condition by replacing hwgroup
220 * spinlock with private per-tape spinlock.
221 * Ver 1.16 Sep 1 99 Add OnStream tape support.
222 * Abort read pipeline on EOD.
223 * Wait for the tape to become ready in case it returns
224 * "in the process of becoming ready" on open().
225 * Fix zero padding of the last written block in
226 * case the tape block size is larger than PAGE_SIZE.
227 * Decrease the default disconnection time to tn.
228 * Ver 1.16e Oct 3 99 Minor fixes.
229 * Ver 1.16e1 Oct 13 99 Patches by Arnold Niessen,
230 * niessen@iae.nl / arnold.niessen@philips.com
231 * GO-1) Undefined code in idetape_read_position
232 * according to Gadi's email
233 * AJN-1) Minor fix asc == 11 should be asc == 0x11
234 * in idetape_issue_packet_command (did effect
235 * debugging output only)
236 * AJN-2) Added more debugging output, and
237 * added ide-tape: where missing. I would also
238 * like to add tape->name where possible
239 * AJN-3) Added different debug_level's
240 * via /proc/ide/hdc/settings
241 * "debug_level" determines amount of debugging output;
242 * can be changed using /proc/ide/hdx/settings
243 * 0 : almost no debugging output
244 * 1 : 0+output errors only
245 * 2 : 1+output all sensekey/asc
246 * 3 : 2+follow all chrdev related procedures
247 * 4 : 3+follow all procedures
248 * 5 : 4+include pc_stack rq_stack info
249 * 6 : 5+USE_COUNT updates
250 * AJN-4) Fixed timeout for retension in idetape_queue_pc_tail
251 * from 5 to 10 minutes
252 * AJN-5) Changed maximum number of blocks to skip when
253 * reading tapes with multiple consecutive write
254 * errors from 100 to 1000 in idetape_get_logical_blk
255 * Proposed changes to code:
256 * 1) output "logical_blk_num" via /proc
257 * 2) output "current_operation" via /proc
258 * 3) Either solve or document the fact that `mt rewind' is
259 * required after reading from /dev/nhtx to be
260 * able to rmmod the idetape module;
261 * Also, sometimes an application finishes but the
262 * device remains `busy' for some time. Same cause ?
263 * Proposed changes to release-notes:
264 * 4) write a simple `quickstart' section in the
265 * release notes; I volunteer if you don't want to
266 * 5) include a pointer to video4linux in the doc
267 * to stimulate video applications
268 * 6) release notes lines 331 and 362: explain what happens
269 * if the application data rate is higher than 1100 KB/s;
270 * similar approach to lower-than-500 kB/s ?
271 * 7) 6.6 Comparison; wouldn't it be better to allow different
272 * strategies for read and write ?
273 * Wouldn't it be better to control the tape buffer
274 * contents instead of the bandwidth ?
275 * 8) line 536: replace will by would (if I understand
276 * this section correctly, a hypothetical and unwanted situation
277 * is being described)
278 * Ver 1.16f Dec 15 99 Change place of the secondary OnStream header frames.
279 * Ver 1.17 Nov 2000 / Jan 2001 Marcel Mol, marcel@mesa.nl
280 * - Add idetape_onstream_mode_sense_tape_parameter_page
281 * function to get tape capacity in frames: tape->capacity.
282 * - Add support for DI-50 drives( or any DI- drive).
283 * - 'workaround' for read error/blank block around block 3000.
284 * - Implement Early warning for end of media for Onstream.
285 * - Cosmetic code changes for readability.
286 * - Idetape_position_tape should not use SKIP bit during
287 * Onstream read recovery.
288 * - Add capacity, logical_blk_num and first/last_frame_position
289 * to /proc/ide/hd?/settings.
290 * - Module use count was gone in the Linux 2.4 driver.
291 * Ver 1.17a Apr 2001 Willem Riede osst@riede.org
292 * - Get drive's actual block size from mode sense block descriptor
293 * - Limit size of pipeline
294 * Ver 1.17b Oct 2002 Alan Stern <stern@rowland.harvard.edu>
295 * Changed IDETAPE_MIN_PIPELINE_STAGES to 1 and actually used
296 * it in the code!
297 * Actually removed aborted stages in idetape_abort_pipeline
298 * instead of just changing the command code.
299 * Made the transfer byte count for Request Sense equal to the
300 * actual length of the data transfer.
301 * Changed handling of partial data transfers: they do not
302 * cause DMA errors.
303 * Moved initiation of DMA transfers to the correct place.
304 * Removed reference to unallocated memory.
305 * Made __idetape_discard_read_pipeline return the number of
306 * sectors skipped, not the number of stages.
307 * Replaced errant kfree() calls with __idetape_kfree_stage().
308 * Fixed off-by-one error in testing the pipeline length.
309 * Fixed handling of filemarks in the read pipeline.
310 * Small code optimization for MTBSF and MTBSFM ioctls.
311 * Don't try to unlock the door during device close if is
312 * already unlocked!
313 * Cosmetic fixes to miscellaneous debugging output messages.
314 * Set the minimum /proc/ide/hd?/settings values for "pipeline",
315 * "pipeline_min", and "pipeline_max" to 1.
316 *
317 * Here are some words from the first releases of hd.c, which are quoted
318 * in ide.c and apply here as well:
319 *
320 * | Special care is recommended. Have Fun!
321 *
322 */
323
324 /*
325 * An overview of the pipelined operation mode.
326 *
327 * In the pipelined write mode, we will usually just add requests to our
328 * pipeline and return immediately, before we even start to service them. The
329 * user program will then have enough time to prepare the next request while
330 * we are still busy servicing previous requests. In the pipelined read mode,
331 * the situation is similar - we add read-ahead requests into the pipeline,
332 * before the user even requested them.
333 *
334 * The pipeline can be viewed as a "safety net" which will be activated when
335 * the system load is high and prevents the user backup program from keeping up
336 * with the current tape speed. At this point, the pipeline will get
337 * shorter and shorter but the tape will still be streaming at the same speed.
338 * Assuming we have enough pipeline stages, the system load will hopefully
339 * decrease before the pipeline is completely empty, and the backup program
340 * will be able to "catch up" and refill the pipeline again.
341 *
342 * When using the pipelined mode, it would be best to disable any type of
343 * buffering done by the user program, as ide-tape already provides all the
344 * benefits in the kernel, where it can be done in a more efficient way.
345 * As we will usually not block the user program on a request, the most
346 * efficient user code will then be a simple read-write-read-... cycle.
347 * Any additional logic will usually just slow down the backup process.
348 *
349 * Using the pipelined mode, I get a constant over 400 KBps throughput,
350 * which seems to be the maximum throughput supported by my tape.
351 *
352 * However, there are some downfalls:
353 *
354 * 1. We use memory (for data buffers) in proportional to the number
355 * of pipeline stages (each stage is about 26 KB with my tape).
356 * 2. In the pipelined write mode, we cheat and postpone error codes
357 * to the user task. In read mode, the actual tape position
358 * will be a bit further than the last requested block.
359 *
360 * Concerning (1):
361 *
362 * 1. We allocate stages dynamically only when we need them. When
363 * we don't need them, we don't consume additional memory. In
364 * case we can't allocate stages, we just manage without them
365 * (at the expense of decreased throughput) so when Linux is
366 * tight in memory, we will not pose additional difficulties.
367 *
368 * 2. The maximum number of stages (which is, in fact, the maximum
369 * amount of memory) which we allocate is limited by the compile
370 * time parameter IDETAPE_MAX_PIPELINE_STAGES.
371 *
372 * 3. The maximum number of stages is a controlled parameter - We
373 * don't start from the user defined maximum number of stages
374 * but from the lower IDETAPE_MIN_PIPELINE_STAGES (again, we
375 * will not even allocate this amount of stages if the user
376 * program can't handle the speed). We then implement a feedback
377 * loop which checks if the pipeline is empty, and if it is, we
378 * increase the maximum number of stages as necessary until we
379 * reach the optimum value which just manages to keep the tape
380 * busy with minimum allocated memory or until we reach
381 * IDETAPE_MAX_PIPELINE_STAGES.
382 *
383 * Concerning (2):
384 *
385 * In pipelined write mode, ide-tape can not return accurate error codes
386 * to the user program since we usually just add the request to the
387 * pipeline without waiting for it to be serviced. In case an error
388 * occurs, I will report it on the next user request.
389 *
390 * In the pipelined read mode, subsequent read requests or forward
391 * filemark spacing will perform correctly, as we preserve all blocks
392 * and filemarks which we encountered during our excess read-ahead.
393 *
394 * For accurate tape positioning and error reporting, disabling
395 * pipelined mode might be the best option.
396 *
397 * You can enable/disable/tune the pipelined operation mode by adjusting
398 * the compile time parameters below.
399 */
400
401 /*
402 * Possible improvements.
403 *
404 * 1. Support for the ATAPI overlap protocol.
405 *
406 * In order to maximize bus throughput, we currently use the DSC
407 * overlap method which enables ide.c to service requests from the
408 * other device while the tape is busy executing a command. The
409 * DSC overlap method involves polling the tape's status register
410 * for the DSC bit, and servicing the other device while the tape
411 * isn't ready.
412 *
413 * In the current QIC development standard (December 1995),
414 * it is recommended that new tape drives will *in addition*
415 * implement the ATAPI overlap protocol, which is used for the
416 * same purpose - efficient use of the IDE bus, but is interrupt
417 * driven and thus has much less CPU overhead.
418 *
419 * ATAPI overlap is likely to be supported in most new ATAPI
420 * devices, including new ATAPI cdroms, and thus provides us
421 * a method by which we can achieve higher throughput when
422 * sharing a (fast) ATA-2 disk with any (slow) new ATAPI device.
423 */
424
425 #define IDETAPE_VERSION "1.19"
426
427 #include <linux/config.h>
428 #include <linux/module.h>
429 #include <linux/types.h>
430 #include <linux/string.h>
431 #include <linux/kernel.h>
432 #include <linux/delay.h>
433 #include <linux/timer.h>
434 #include <linux/mm.h>
435 #include <linux/interrupt.h>
436 #include <linux/jiffies.h>
437 #include <linux/major.h>
438 #include <linux/devfs_fs_kernel.h>
439 #include <linux/errno.h>
440 #include <linux/genhd.h>
441 #include <linux/slab.h>
442 #include <linux/pci.h>
443 #include <linux/ide.h>
444 #include <linux/smp_lock.h>
445 #include <linux/completion.h>
446 #include <linux/bitops.h>
447 #include <linux/mutex.h>
448
449 #include <asm/byteorder.h>
450 #include <asm/irq.h>
451 #include <asm/uaccess.h>
452 #include <asm/io.h>
453 #include <asm/unaligned.h>
454
455 /*
456 * partition
457 */
458 typedef struct os_partition_s {
459 __u8 partition_num;
460 __u8 par_desc_ver;
461 __u16 wrt_pass_cntr;
462 __u32 first_frame_addr;
463 __u32 last_frame_addr;
464 __u32 eod_frame_addr;
465 } os_partition_t;
466
467 /*
468 * DAT entry
469 */
470 typedef struct os_dat_entry_s {
471 __u32 blk_sz;
472 __u16 blk_cnt;
473 __u8 flags;
474 __u8 reserved;
475 } os_dat_entry_t;
476
477 /*
478 * DAT
479 */
480 #define OS_DAT_FLAGS_DATA (0xc)
481 #define OS_DAT_FLAGS_MARK (0x1)
482
483 typedef struct os_dat_s {
484 __u8 dat_sz;
485 __u8 reserved1;
486 __u8 entry_cnt;
487 __u8 reserved3;
488 os_dat_entry_t dat_list[16];
489 } os_dat_t;
490
491 #include <linux/mtio.h>
492
493 /**************************** Tunable parameters *****************************/
494
495
496 /*
497 * Pipelined mode parameters.
498 *
499 * We try to use the minimum number of stages which is enough to
500 * keep the tape constantly streaming. To accomplish that, we implement
501 * a feedback loop around the maximum number of stages:
502 *
503 * We start from MIN maximum stages (we will not even use MIN stages
504 * if we don't need them), increment it by RATE*(MAX-MIN)
505 * whenever we sense that the pipeline is empty, until we reach
506 * the optimum value or until we reach MAX.
507 *
508 * Setting the following parameter to 0 is illegal: the pipelined mode
509 * cannot be disabled (calculate_speeds() divides by tape->max_stages.)
510 */
511 #define IDETAPE_MIN_PIPELINE_STAGES 1
512 #define IDETAPE_MAX_PIPELINE_STAGES 400
513 #define IDETAPE_INCREASE_STAGES_RATE 20
514
515 /*
516 * The following are used to debug the driver:
517 *
518 * Setting IDETAPE_DEBUG_INFO to 1 will report device capabilities.
519 * Setting IDETAPE_DEBUG_LOG to 1 will log driver flow control.
520 * Setting IDETAPE_DEBUG_BUGS to 1 will enable self-sanity checks in
521 * some places.
522 *
523 * Setting them to 0 will restore normal operation mode:
524 *
525 * 1. Disable logging normal successful operations.
526 * 2. Disable self-sanity checks.
527 * 3. Errors will still be logged, of course.
528 *
529 * All the #if DEBUG code will be removed some day, when the driver
530 * is verified to be stable enough. This will make it much more
531 * esthetic.
532 */
533 #define IDETAPE_DEBUG_INFO 0
534 #define IDETAPE_DEBUG_LOG 0
535 #define IDETAPE_DEBUG_BUGS 1
536
537 /*
538 * After each failed packet command we issue a request sense command
539 * and retry the packet command IDETAPE_MAX_PC_RETRIES times.
540 *
541 * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
542 */
543 #define IDETAPE_MAX_PC_RETRIES 3
544
545 /*
546 * With each packet command, we allocate a buffer of
547 * IDETAPE_PC_BUFFER_SIZE bytes. This is used for several packet
548 * commands (Not for READ/WRITE commands).
549 */
550 #define IDETAPE_PC_BUFFER_SIZE 256
551
552 /*
553 * In various places in the driver, we need to allocate storage
554 * for packet commands and requests, which will remain valid while
555 * we leave the driver to wait for an interrupt or a timeout event.
556 */
557 #define IDETAPE_PC_STACK (10 + IDETAPE_MAX_PC_RETRIES)
558
559 /*
560 * Some drives (for example, Seagate STT3401A Travan) require a very long
561 * timeout, because they don't return an interrupt or clear their busy bit
562 * until after the command completes (even retension commands).
563 */
564 #define IDETAPE_WAIT_CMD (900*HZ)
565
566 /*
567 * The following parameter is used to select the point in the internal
568 * tape fifo in which we will start to refill the buffer. Decreasing
569 * the following parameter will improve the system's latency and
570 * interactive response, while using a high value might improve sytem
571 * throughput.
572 */
573 #define IDETAPE_FIFO_THRESHOLD 2
574
575 /*
576 * DSC polling parameters.
577 *
578 * Polling for DSC (a single bit in the status register) is a very
579 * important function in ide-tape. There are two cases in which we
580 * poll for DSC:
581 *
582 * 1. Before a read/write packet command, to ensure that we
583 * can transfer data from/to the tape's data buffers, without
584 * causing an actual media access. In case the tape is not
585 * ready yet, we take out our request from the device
586 * request queue, so that ide.c will service requests from
587 * the other device on the same interface meanwhile.
588 *
589 * 2. After the successful initialization of a "media access
590 * packet command", which is a command which can take a long
591 * time to complete (it can be several seconds or even an hour).
592 *
593 * Again, we postpone our request in the middle to free the bus
594 * for the other device. The polling frequency here should be
595 * lower than the read/write frequency since those media access
596 * commands are slow. We start from a "fast" frequency -
597 * IDETAPE_DSC_MA_FAST (one second), and if we don't receive DSC
598 * after IDETAPE_DSC_MA_THRESHOLD (5 minutes), we switch it to a
599 * lower frequency - IDETAPE_DSC_MA_SLOW (1 minute).
600 *
601 * We also set a timeout for the timer, in case something goes wrong.
602 * The timeout should be longer then the maximum execution time of a
603 * tape operation.
604 */
605
606 /*
607 * DSC timings.
608 */
609 #define IDETAPE_DSC_RW_MIN 5*HZ/100 /* 50 msec */
610 #define IDETAPE_DSC_RW_MAX 40*HZ/100 /* 400 msec */
611 #define IDETAPE_DSC_RW_TIMEOUT 2*60*HZ /* 2 minutes */
612 #define IDETAPE_DSC_MA_FAST 2*HZ /* 2 seconds */
613 #define IDETAPE_DSC_MA_THRESHOLD 5*60*HZ /* 5 minutes */
614 #define IDETAPE_DSC_MA_SLOW 30*HZ /* 30 seconds */
615 #define IDETAPE_DSC_MA_TIMEOUT 2*60*60*HZ /* 2 hours */
616
617 /*************************** End of tunable parameters ***********************/
618
619 /*
620 * Debugging/Performance analysis
621 *
622 * I/O trace support
623 */
624 #define USE_IOTRACE 0
625 #if USE_IOTRACE
626 #include <linux/io_trace.h>
627 #define IO_IDETAPE_FIFO 500
628 #endif
629
630 /*
631 * Read/Write error simulation
632 */
633 #define SIMULATE_ERRORS 0
634
635 /*
636 * For general magnetic tape device compatibility.
637 */
638 typedef enum {
639 idetape_direction_none,
640 idetape_direction_read,
641 idetape_direction_write
642 } idetape_chrdev_direction_t;
643
644 struct idetape_bh {
645 unsigned short b_size;
646 atomic_t b_count;
647 struct idetape_bh *b_reqnext;
648 char *b_data;
649 };
650
651 /*
652 * Our view of a packet command.
653 */
654 typedef struct idetape_packet_command_s {
655 u8 c[12]; /* Actual packet bytes */
656 int retries; /* On each retry, we increment retries */
657 int error; /* Error code */
658 int request_transfer; /* Bytes to transfer */
659 int actually_transferred; /* Bytes actually transferred */
660 int buffer_size; /* Size of our data buffer */
661 struct idetape_bh *bh;
662 char *b_data;
663 int b_count;
664 u8 *buffer; /* Data buffer */
665 u8 *current_position; /* Pointer into the above buffer */
666 ide_startstop_t (*callback) (ide_drive_t *); /* Called when this packet command is completed */
667 u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE]; /* Temporary buffer */
668 unsigned long flags; /* Status/Action bit flags: long for set_bit */
669 } idetape_pc_t;
670
671 /*
672 * Packet command flag bits.
673 */
674 /* Set when an error is considered normal - We won't retry */
675 #define PC_ABORT 0
676 /* 1 When polling for DSC on a media access command */
677 #define PC_WAIT_FOR_DSC 1
678 /* 1 when we prefer to use DMA if possible */
679 #define PC_DMA_RECOMMENDED 2
680 /* 1 while DMA in progress */
681 #define PC_DMA_IN_PROGRESS 3
682 /* 1 when encountered problem during DMA */
683 #define PC_DMA_ERROR 4
684 /* Data direction */
685 #define PC_WRITING 5
686
687 /*
688 * Capabilities and Mechanical Status Page
689 */
690 typedef struct {
691 unsigned page_code :6; /* Page code - Should be 0x2a */
692 __u8 reserved0_6 :1;
693 __u8 ps :1; /* parameters saveable */
694 __u8 page_length; /* Page Length - Should be 0x12 */
695 __u8 reserved2, reserved3;
696 unsigned ro :1; /* Read Only Mode */
697 unsigned reserved4_1234 :4;
698 unsigned sprev :1; /* Supports SPACE in the reverse direction */
699 unsigned reserved4_67 :2;
700 unsigned reserved5_012 :3;
701 unsigned efmt :1; /* Supports ERASE command initiated formatting */
702 unsigned reserved5_4 :1;
703 unsigned qfa :1; /* Supports the QFA two partition formats */
704 unsigned reserved5_67 :2;
705 unsigned lock :1; /* Supports locking the volume */
706 unsigned locked :1; /* The volume is locked */
707 unsigned prevent :1; /* The device defaults in the prevent state after power up */
708 unsigned eject :1; /* The device can eject the volume */
709 __u8 disconnect :1; /* The device can break request > ctl */
710 __u8 reserved6_5 :1;
711 unsigned ecc :1; /* Supports error correction */
712 unsigned cmprs :1; /* Supports data compression */
713 unsigned reserved7_0 :1;
714 unsigned blk512 :1; /* Supports 512 bytes block size */
715 unsigned blk1024 :1; /* Supports 1024 bytes block size */
716 unsigned reserved7_3_6 :4;
717 unsigned blk32768 :1; /* slowb - the device restricts the byte count for PIO */
718 /* transfers for slow buffer memory ??? */
719 /* Also 32768 block size in some cases */
720 __u16 max_speed; /* Maximum speed supported in KBps */
721 __u8 reserved10, reserved11;
722 __u16 ctl; /* Continuous Transfer Limit in blocks */
723 __u16 speed; /* Current Speed, in KBps */
724 __u16 buffer_size; /* Buffer Size, in 512 bytes */
725 __u8 reserved18, reserved19;
726 } idetape_capabilities_page_t;
727
728 /*
729 * Block Size Page
730 */
731 typedef struct {
732 unsigned page_code :6; /* Page code - Should be 0x30 */
733 unsigned reserved1_6 :1;
734 unsigned ps :1;
735 __u8 page_length; /* Page Length - Should be 2 */
736 __u8 reserved2;
737 unsigned play32 :1;
738 unsigned play32_5 :1;
739 unsigned reserved2_23 :2;
740 unsigned record32 :1;
741 unsigned record32_5 :1;
742 unsigned reserved2_6 :1;
743 unsigned one :1;
744 } idetape_block_size_page_t;
745
746 /*
747 * A pipeline stage.
748 */
749 typedef struct idetape_stage_s {
750 struct request rq; /* The corresponding request */
751 struct idetape_bh *bh; /* The data buffers */
752 struct idetape_stage_s *next; /* Pointer to the next stage */
753 } idetape_stage_t;
754
755 /*
756 * REQUEST SENSE packet command result - Data Format.
757 */
758 typedef struct {
759 unsigned error_code :7; /* Current of deferred errors */
760 unsigned valid :1; /* The information field conforms to QIC-157C */
761 __u8 reserved1 :8; /* Segment Number - Reserved */
762 unsigned sense_key :4; /* Sense Key */
763 unsigned reserved2_4 :1; /* Reserved */
764 unsigned ili :1; /* Incorrect Length Indicator */
765 unsigned eom :1; /* End Of Medium */
766 unsigned filemark :1; /* Filemark */
767 __u32 information __attribute__ ((packed));
768 __u8 asl; /* Additional sense length (n-7) */
769 __u32 command_specific; /* Additional command specific information */
770 __u8 asc; /* Additional Sense Code */
771 __u8 ascq; /* Additional Sense Code Qualifier */
772 __u8 replaceable_unit_code; /* Field Replaceable Unit Code */
773 unsigned sk_specific1 :7; /* Sense Key Specific */
774 unsigned sksv :1; /* Sense Key Specific information is valid */
775 __u8 sk_specific2; /* Sense Key Specific */
776 __u8 sk_specific3; /* Sense Key Specific */
777 __u8 pad[2]; /* Padding to 20 bytes */
778 } idetape_request_sense_result_t;
779
780
781 /*
782 * Most of our global data which we need to save even as we leave the
783 * driver due to an interrupt or a timer event is stored in a variable
784 * of type idetape_tape_t, defined below.
785 */
786 typedef struct ide_tape_obj {
787 ide_drive_t *drive;
788 ide_driver_t *driver;
789 struct gendisk *disk;
790 struct kref kref;
791
792 /*
793 * Since a typical character device operation requires more
794 * than one packet command, we provide here enough memory
795 * for the maximum of interconnected packet commands.
796 * The packet commands are stored in the circular array pc_stack.
797 * pc_stack_index points to the last used entry, and warps around
798 * to the start when we get to the last array entry.
799 *
800 * pc points to the current processed packet command.
801 *
802 * failed_pc points to the last failed packet command, or contains
803 * NULL if we do not need to retry any packet command. This is
804 * required since an additional packet command is needed before the
805 * retry, to get detailed information on what went wrong.
806 */
807 /* Current packet command */
808 idetape_pc_t *pc;
809 /* Last failed packet command */
810 idetape_pc_t *failed_pc;
811 /* Packet command stack */
812 idetape_pc_t pc_stack[IDETAPE_PC_STACK];
813 /* Next free packet command storage space */
814 int pc_stack_index;
815 struct request rq_stack[IDETAPE_PC_STACK];
816 /* We implement a circular array */
817 int rq_stack_index;
818
819 /*
820 * DSC polling variables.
821 *
822 * While polling for DSC we use postponed_rq to postpone the
823 * current request so that ide.c will be able to service
824 * pending requests on the other device. Note that at most
825 * we will have only one DSC (usually data transfer) request
826 * in the device request queue. Additional requests can be
827 * queued in our internal pipeline, but they will be visible
828 * to ide.c only one at a time.
829 */
830 struct request *postponed_rq;
831 /* The time in which we started polling for DSC */
832 unsigned long dsc_polling_start;
833 /* Timer used to poll for dsc */
834 struct timer_list dsc_timer;
835 /* Read/Write dsc polling frequency */
836 unsigned long best_dsc_rw_frequency;
837 /* The current polling frequency */
838 unsigned long dsc_polling_frequency;
839 /* Maximum waiting time */
840 unsigned long dsc_timeout;
841
842 /*
843 * Read position information
844 */
845 u8 partition;
846 /* Current block */
847 unsigned int first_frame_position;
848 unsigned int last_frame_position;
849 unsigned int blocks_in_buffer;
850
851 /*
852 * Last error information
853 */
854 u8 sense_key, asc, ascq;
855
856 /*
857 * Character device operation
858 */
859 unsigned int minor;
860 /* device name */
861 char name[4];
862 /* Current character device data transfer direction */
863 idetape_chrdev_direction_t chrdev_direction;
864
865 /*
866 * Device information
867 */
868 /* Usually 512 or 1024 bytes */
869 unsigned short tape_block_size;
870 int user_bs_factor;
871 /* Copy of the tape's Capabilities and Mechanical Page */
872 idetape_capabilities_page_t capabilities;
873
874 /*
875 * Active data transfer request parameters.
876 *
877 * At most, there is only one ide-tape originated data transfer
878 * request in the device request queue. This allows ide.c to
879 * easily service requests from the other device when we
880 * postpone our active request. In the pipelined operation
881 * mode, we use our internal pipeline structure to hold
882 * more data requests.
883 *
884 * The data buffer size is chosen based on the tape's
885 * recommendation.
886 */
887 /* Pointer to the request which is waiting in the device request queue */
888 struct request *active_data_request;
889 /* Data buffer size (chosen based on the tape's recommendation */
890 int stage_size;
891 idetape_stage_t *merge_stage;
892 int merge_stage_size;
893 struct idetape_bh *bh;
894 char *b_data;
895 int b_count;
896
897 /*
898 * Pipeline parameters.
899 *
900 * To accomplish non-pipelined mode, we simply set the following
901 * variables to zero (or NULL, where appropriate).
902 */
903 /* Number of currently used stages */
904 int nr_stages;
905 /* Number of pending stages */
906 int nr_pending_stages;
907 /* We will not allocate more than this number of stages */
908 int max_stages, min_pipeline, max_pipeline;
909 /* The first stage which will be removed from the pipeline */
910 idetape_stage_t *first_stage;
911 /* The currently active stage */
912 idetape_stage_t *active_stage;
913 /* Will be serviced after the currently active request */
914 idetape_stage_t *next_stage;
915 /* New requests will be added to the pipeline here */
916 idetape_stage_t *last_stage;
917 /* Optional free stage which we can use */
918 idetape_stage_t *cache_stage;
919 int pages_per_stage;
920 /* Wasted space in each stage */
921 int excess_bh_size;
922
923 /* Status/Action flags: long for set_bit */
924 unsigned long flags;
925 /* protects the ide-tape queue */
926 spinlock_t spinlock;
927
928 /*
929 * Measures average tape speed
930 */
931 unsigned long avg_time;
932 int avg_size;
933 int avg_speed;
934
935 /* last sense information */
936 idetape_request_sense_result_t sense;
937
938 char vendor_id[10];
939 char product_id[18];
940 char firmware_revision[6];
941 int firmware_revision_num;
942
943 /* the door is currently locked */
944 int door_locked;
945 /* the tape hardware is write protected */
946 char drv_write_prot;
947 /* the tape is write protected (hardware or opened as read-only) */
948 char write_prot;
949
950 /*
951 * Limit the number of times a request can
952 * be postponed, to avoid an infinite postpone
953 * deadlock.
954 */
955 /* request postpone count limit */
956 int postpone_cnt;
957
958 /*
959 * Measures number of frames:
960 *
961 * 1. written/read to/from the driver pipeline (pipeline_head).
962 * 2. written/read to/from the tape buffers (idetape_bh).
963 * 3. written/read by the tape to/from the media (tape_head).
964 */
965 int pipeline_head;
966 int buffer_head;
967 int tape_head;
968 int last_tape_head;
969
970 /*
971 * Speed control at the tape buffers input/output
972 */
973 unsigned long insert_time;
974 int insert_size;
975 int insert_speed;
976 int max_insert_speed;
977 int measure_insert_time;
978
979 /*
980 * Measure tape still time, in milliseconds
981 */
982 unsigned long tape_still_time_begin;
983 int tape_still_time;
984
985 /*
986 * Speed regulation negative feedback loop
987 */
988 int speed_control;
989 int pipeline_head_speed;
990 int controlled_pipeline_head_speed;
991 int uncontrolled_pipeline_head_speed;
992 int controlled_last_pipeline_head;
993 int uncontrolled_last_pipeline_head;
994 unsigned long uncontrolled_pipeline_head_time;
995 unsigned long controlled_pipeline_head_time;
996 int controlled_previous_pipeline_head;
997 int uncontrolled_previous_pipeline_head;
998 unsigned long controlled_previous_head_time;
999 unsigned long uncontrolled_previous_head_time;
1000 int restart_speed_control_req;
1001
1002 /*
1003 * Debug_level determines amount of debugging output;
1004 * can be changed using /proc/ide/hdx/settings
1005 * 0 : almost no debugging output
1006 * 1 : 0+output errors only
1007 * 2 : 1+output all sensekey/asc
1008 * 3 : 2+follow all chrdev related procedures
1009 * 4 : 3+follow all procedures
1010 * 5 : 4+include pc_stack rq_stack info
1011 * 6 : 5+USE_COUNT updates
1012 */
1013 int debug_level;
1014 } idetape_tape_t;
1015
1016 static DEFINE_MUTEX(idetape_ref_mutex);
1017
1018 static struct class *idetape_sysfs_class;
1019
1020 #define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref)
1021
1022 #define ide_tape_g(disk) \
1023 container_of((disk)->private_data, struct ide_tape_obj, driver)
1024
1025 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
1026 {
1027 struct ide_tape_obj *tape = NULL;
1028
1029 mutex_lock(&idetape_ref_mutex);
1030 tape = ide_tape_g(disk);
1031 if (tape)
1032 kref_get(&tape->kref);
1033 mutex_unlock(&idetape_ref_mutex);
1034 return tape;
1035 }
1036
1037 static void ide_tape_release(struct kref *);
1038
1039 static void ide_tape_put(struct ide_tape_obj *tape)
1040 {
1041 mutex_lock(&idetape_ref_mutex);
1042 kref_put(&tape->kref, ide_tape_release);
1043 mutex_unlock(&idetape_ref_mutex);
1044 }
1045
1046 /*
1047 * Tape door status
1048 */
1049 #define DOOR_UNLOCKED 0
1050 #define DOOR_LOCKED 1
1051 #define DOOR_EXPLICITLY_LOCKED 2
1052
1053 /*
1054 * Tape flag bits values.
1055 */
1056 #define IDETAPE_IGNORE_DSC 0
1057 #define IDETAPE_ADDRESS_VALID 1 /* 0 When the tape position is unknown */
1058 #define IDETAPE_BUSY 2 /* Device already opened */
1059 #define IDETAPE_PIPELINE_ERROR 3 /* Error detected in a pipeline stage */
1060 #define IDETAPE_DETECT_BS 4 /* Attempt to auto-detect the current user block size */
1061 #define IDETAPE_FILEMARK 5 /* Currently on a filemark */
1062 #define IDETAPE_DRQ_INTERRUPT 6 /* DRQ interrupt device */
1063 #define IDETAPE_READ_ERROR 7
1064 #define IDETAPE_PIPELINE_ACTIVE 8 /* pipeline active */
1065 /* 0 = no tape is loaded, so we don't rewind after ejecting */
1066 #define IDETAPE_MEDIUM_PRESENT 9
1067
1068 /*
1069 * Supported ATAPI tape drives packet commands
1070 */
1071 #define IDETAPE_TEST_UNIT_READY_CMD 0x00
1072 #define IDETAPE_REWIND_CMD 0x01
1073 #define IDETAPE_REQUEST_SENSE_CMD 0x03
1074 #define IDETAPE_READ_CMD 0x08
1075 #define IDETAPE_WRITE_CMD 0x0a
1076 #define IDETAPE_WRITE_FILEMARK_CMD 0x10
1077 #define IDETAPE_SPACE_CMD 0x11
1078 #define IDETAPE_INQUIRY_CMD 0x12
1079 #define IDETAPE_ERASE_CMD 0x19
1080 #define IDETAPE_MODE_SENSE_CMD 0x1a
1081 #define IDETAPE_MODE_SELECT_CMD 0x15
1082 #define IDETAPE_LOAD_UNLOAD_CMD 0x1b
1083 #define IDETAPE_PREVENT_CMD 0x1e
1084 #define IDETAPE_LOCATE_CMD 0x2b
1085 #define IDETAPE_READ_POSITION_CMD 0x34
1086 #define IDETAPE_READ_BUFFER_CMD 0x3c
1087 #define IDETAPE_SET_SPEED_CMD 0xbb
1088
1089 /*
1090 * Some defines for the READ BUFFER command
1091 */
1092 #define IDETAPE_RETRIEVE_FAULTY_BLOCK 6
1093
1094 /*
1095 * Some defines for the SPACE command
1096 */
1097 #define IDETAPE_SPACE_OVER_FILEMARK 1
1098 #define IDETAPE_SPACE_TO_EOD 3
1099
1100 /*
1101 * Some defines for the LOAD UNLOAD command
1102 */
1103 #define IDETAPE_LU_LOAD_MASK 1
1104 #define IDETAPE_LU_RETENSION_MASK 2
1105 #define IDETAPE_LU_EOT_MASK 4
1106
1107 /*
1108 * Special requests for our block device strategy routine.
1109 *
1110 * In order to service a character device command, we add special
1111 * requests to the tail of our block device request queue and wait
1112 * for their completion.
1113 */
1114
1115 enum {
1116 REQ_IDETAPE_PC1 = (1 << 0), /* packet command (first stage) */
1117 REQ_IDETAPE_PC2 = (1 << 1), /* packet command (second stage) */
1118 REQ_IDETAPE_READ = (1 << 2),
1119 REQ_IDETAPE_WRITE = (1 << 3),
1120 REQ_IDETAPE_READ_BUFFER = (1 << 4),
1121 };
1122
1123 /*
1124 * Error codes which are returned in rq->errors to the higher part
1125 * of the driver.
1126 */
1127 #define IDETAPE_ERROR_GENERAL 101
1128 #define IDETAPE_ERROR_FILEMARK 102
1129 #define IDETAPE_ERROR_EOD 103
1130
1131 /*
1132 * The following is used to format the general configuration word of
1133 * the ATAPI IDENTIFY DEVICE command.
1134 */
1135 struct idetape_id_gcw {
1136 unsigned packet_size :2; /* Packet Size */
1137 unsigned reserved234 :3; /* Reserved */
1138 unsigned drq_type :2; /* Command packet DRQ type */
1139 unsigned removable :1; /* Removable media */
1140 unsigned device_type :5; /* Device type */
1141 unsigned reserved13 :1; /* Reserved */
1142 unsigned protocol :2; /* Protocol type */
1143 };
1144
1145 /*
1146 * INQUIRY packet command - Data Format (From Table 6-8 of QIC-157C)
1147 */
1148 typedef struct {
1149 unsigned device_type :5; /* Peripheral Device Type */
1150 unsigned reserved0_765 :3; /* Peripheral Qualifier - Reserved */
1151 unsigned reserved1_6t0 :7; /* Reserved */
1152 unsigned rmb :1; /* Removable Medium Bit */
1153 unsigned ansi_version :3; /* ANSI Version */
1154 unsigned ecma_version :3; /* ECMA Version */
1155 unsigned iso_version :2; /* ISO Version */
1156 unsigned response_format :4; /* Response Data Format */
1157 unsigned reserved3_45 :2; /* Reserved */
1158 unsigned reserved3_6 :1; /* TrmIOP - Reserved */
1159 unsigned reserved3_7 :1; /* AENC - Reserved */
1160 __u8 additional_length; /* Additional Length (total_length-4) */
1161 __u8 rsv5, rsv6, rsv7; /* Reserved */
1162 __u8 vendor_id[8]; /* Vendor Identification */
1163 __u8 product_id[16]; /* Product Identification */
1164 __u8 revision_level[4]; /* Revision Level */
1165 __u8 vendor_specific[20]; /* Vendor Specific - Optional */
1166 __u8 reserved56t95[40]; /* Reserved - Optional */
1167 /* Additional information may be returned */
1168 } idetape_inquiry_result_t;
1169
1170 /*
1171 * READ POSITION packet command - Data Format (From Table 6-57)
1172 */
1173 typedef struct {
1174 unsigned reserved0_10 :2; /* Reserved */
1175 unsigned bpu :1; /* Block Position Unknown */
1176 unsigned reserved0_543 :3; /* Reserved */
1177 unsigned eop :1; /* End Of Partition */
1178 unsigned bop :1; /* Beginning Of Partition */
1179 u8 partition; /* Partition Number */
1180 u8 reserved2, reserved3; /* Reserved */
1181 u32 first_block; /* First Block Location */
1182 u32 last_block; /* Last Block Location (Optional) */
1183 u8 reserved12; /* Reserved */
1184 u8 blocks_in_buffer[3]; /* Blocks In Buffer - (Optional) */
1185 u32 bytes_in_buffer; /* Bytes In Buffer (Optional) */
1186 } idetape_read_position_result_t;
1187
1188 /*
1189 * Follows structures which are related to the SELECT SENSE / MODE SENSE
1190 * packet commands. Those packet commands are still not supported
1191 * by ide-tape.
1192 */
1193 #define IDETAPE_BLOCK_DESCRIPTOR 0
1194 #define IDETAPE_CAPABILITIES_PAGE 0x2a
1195 #define IDETAPE_PARAMTR_PAGE 0x2b /* Onstream DI-x0 only */
1196 #define IDETAPE_BLOCK_SIZE_PAGE 0x30
1197 #define IDETAPE_BUFFER_FILLING_PAGE 0x33
1198
1199 /*
1200 * Mode Parameter Header for the MODE SENSE packet command
1201 */
1202 typedef struct {
1203 __u8 mode_data_length; /* Length of the following data transfer */
1204 __u8 medium_type; /* Medium Type */
1205 __u8 dsp; /* Device Specific Parameter */
1206 __u8 bdl; /* Block Descriptor Length */
1207 #if 0
1208 /* data transfer page */
1209 __u8 page_code :6;
1210 __u8 reserved0_6 :1;
1211 __u8 ps :1; /* parameters saveable */
1212 __u8 page_length; /* page Length == 0x02 */
1213 __u8 reserved2;
1214 __u8 read32k :1; /* 32k blk size (data only) */
1215 __u8 read32k5 :1; /* 32.5k blk size (data&AUX) */
1216 __u8 reserved3_23 :2;
1217 __u8 write32k :1; /* 32k blk size (data only) */
1218 __u8 write32k5 :1; /* 32.5k blk size (data&AUX) */
1219 __u8 reserved3_6 :1;
1220 __u8 streaming :1; /* streaming mode enable */
1221 #endif
1222 } idetape_mode_parameter_header_t;
1223
1224 /*
1225 * Mode Parameter Block Descriptor the MODE SENSE packet command
1226 *
1227 * Support for block descriptors is optional.
1228 */
1229 typedef struct {
1230 __u8 density_code; /* Medium density code */
1231 __u8 blocks[3]; /* Number of blocks */
1232 __u8 reserved4; /* Reserved */
1233 __u8 length[3]; /* Block Length */
1234 } idetape_parameter_block_descriptor_t;
1235
1236 /*
1237 * The Data Compression Page, as returned by the MODE SENSE packet command.
1238 */
1239 typedef struct {
1240 unsigned page_code :6; /* Page Code - Should be 0xf */
1241 unsigned reserved0 :1; /* Reserved */
1242 unsigned ps :1;
1243 __u8 page_length; /* Page Length - Should be 14 */
1244 unsigned reserved2 :6; /* Reserved */
1245 unsigned dcc :1; /* Data Compression Capable */
1246 unsigned dce :1; /* Data Compression Enable */
1247 unsigned reserved3 :5; /* Reserved */
1248 unsigned red :2; /* Report Exception on Decompression */
1249 unsigned dde :1; /* Data Decompression Enable */
1250 __u32 ca; /* Compression Algorithm */
1251 __u32 da; /* Decompression Algorithm */
1252 __u8 reserved[4]; /* Reserved */
1253 } idetape_data_compression_page_t;
1254
1255 /*
1256 * The Medium Partition Page, as returned by the MODE SENSE packet command.
1257 */
1258 typedef struct {
1259 unsigned page_code :6; /* Page Code - Should be 0x11 */
1260 unsigned reserved1_6 :1; /* Reserved */
1261 unsigned ps :1;
1262 __u8 page_length; /* Page Length - Should be 6 */
1263 __u8 map; /* Maximum Additional Partitions - Should be 0 */
1264 __u8 apd; /* Additional Partitions Defined - Should be 0 */
1265 unsigned reserved4_012 :3; /* Reserved */
1266 unsigned psum :2; /* Should be 0 */
1267 unsigned idp :1; /* Should be 0 */
1268 unsigned sdp :1; /* Should be 0 */
1269 unsigned fdp :1; /* Fixed Data Partitions */
1270 __u8 mfr; /* Medium Format Recognition */
1271 __u8 reserved[2]; /* Reserved */
1272 } idetape_medium_partition_page_t;
1273
1274 /*
1275 * Run time configurable parameters.
1276 */
1277 typedef struct {
1278 int dsc_rw_frequency;
1279 int dsc_media_access_frequency;
1280 int nr_stages;
1281 } idetape_config_t;
1282
1283 /*
1284 * The variables below are used for the character device interface.
1285 * Additional state variables are defined in our ide_drive_t structure.
1286 */
1287 static struct ide_tape_obj * idetape_devs[MAX_HWIFS * MAX_DRIVES];
1288
1289 #define ide_tape_f(file) ((file)->private_data)
1290
1291 static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
1292 {
1293 struct ide_tape_obj *tape = NULL;
1294
1295 mutex_lock(&idetape_ref_mutex);
1296 tape = idetape_devs[i];
1297 if (tape)
1298 kref_get(&tape->kref);
1299 mutex_unlock(&idetape_ref_mutex);
1300 return tape;
1301 }
1302
1303 /*
1304 * Function declarations
1305 *
1306 */
1307 static int idetape_chrdev_release (struct inode *inode, struct file *filp);
1308 static void idetape_write_release (ide_drive_t *drive, unsigned int minor);
1309
1310 /*
1311 * Too bad. The drive wants to send us data which we are not ready to accept.
1312 * Just throw it away.
1313 */
1314 static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount)
1315 {
1316 while (bcount--)
1317 (void) HWIF(drive)->INB(IDE_DATA_REG);
1318 }
1319
1320 static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
1321 {
1322 struct idetape_bh *bh = pc->bh;
1323 int count;
1324
1325 while (bcount) {
1326 #if IDETAPE_DEBUG_BUGS
1327 if (bh == NULL) {
1328 printk(KERN_ERR "ide-tape: bh == NULL in "
1329 "idetape_input_buffers\n");
1330 idetape_discard_data(drive, bcount);
1331 return;
1332 }
1333 #endif /* IDETAPE_DEBUG_BUGS */
1334 count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount);
1335 HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count);
1336 bcount -= count;
1337 atomic_add(count, &bh->b_count);
1338 if (atomic_read(&bh->b_count) == bh->b_size) {
1339 bh = bh->b_reqnext;
1340 if (bh)
1341 atomic_set(&bh->b_count, 0);
1342 }
1343 }
1344 pc->bh = bh;
1345 }
1346
1347 static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
1348 {
1349 struct idetape_bh *bh = pc->bh;
1350 int count;
1351
1352 while (bcount) {
1353 #if IDETAPE_DEBUG_BUGS
1354 if (bh == NULL) {
1355 printk(KERN_ERR "ide-tape: bh == NULL in "
1356 "idetape_output_buffers\n");
1357 return;
1358 }
1359 #endif /* IDETAPE_DEBUG_BUGS */
1360 count = min((unsigned int)pc->b_count, (unsigned int)bcount);
1361 HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count);
1362 bcount -= count;
1363 pc->b_data += count;
1364 pc->b_count -= count;
1365 if (!pc->b_count) {
1366 pc->bh = bh = bh->b_reqnext;
1367 if (bh) {
1368 pc->b_data = bh->b_data;
1369 pc->b_count = atomic_read(&bh->b_count);
1370 }
1371 }
1372 }
1373 }
1374
1375 static void idetape_update_buffers (idetape_pc_t *pc)
1376 {
1377 struct idetape_bh *bh = pc->bh;
1378 int count;
1379 unsigned int bcount = pc->actually_transferred;
1380
1381 if (test_bit(PC_WRITING, &pc->flags))
1382 return;
1383 while (bcount) {
1384 #if IDETAPE_DEBUG_BUGS
1385 if (bh == NULL) {
1386 printk(KERN_ERR "ide-tape: bh == NULL in "
1387 "idetape_update_buffers\n");
1388 return;
1389 }
1390 #endif /* IDETAPE_DEBUG_BUGS */
1391 count = min((unsigned int)bh->b_size, (unsigned int)bcount);
1392 atomic_set(&bh->b_count, count);
1393 if (atomic_read(&bh->b_count) == bh->b_size)
1394 bh = bh->b_reqnext;
1395 bcount -= count;
1396 }
1397 pc->bh = bh;
1398 }
1399
1400 /*
1401 * idetape_next_pc_storage returns a pointer to a place in which we can
1402 * safely store a packet command, even though we intend to leave the
1403 * driver. A storage space for a maximum of IDETAPE_PC_STACK packet
1404 * commands is allocated at initialization time.
1405 */
1406 static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive)
1407 {
1408 idetape_tape_t *tape = drive->driver_data;
1409
1410 #if IDETAPE_DEBUG_LOG
1411 if (tape->debug_level >= 5)
1412 printk(KERN_INFO "ide-tape: pc_stack_index=%d\n",
1413 tape->pc_stack_index);
1414 #endif /* IDETAPE_DEBUG_LOG */
1415 if (tape->pc_stack_index == IDETAPE_PC_STACK)
1416 tape->pc_stack_index=0;
1417 return (&tape->pc_stack[tape->pc_stack_index++]);
1418 }
1419
1420 /*
1421 * idetape_next_rq_storage is used along with idetape_next_pc_storage.
1422 * Since we queue packet commands in the request queue, we need to
1423 * allocate a request, along with the allocation of a packet command.
1424 */
1425
1426 /**************************************************************
1427 * *
1428 * This should get fixed to use kmalloc(.., GFP_ATOMIC) *
1429 * followed later on by kfree(). -ml *
1430 * *
1431 **************************************************************/
1432
1433 static struct request *idetape_next_rq_storage (ide_drive_t *drive)
1434 {
1435 idetape_tape_t *tape = drive->driver_data;
1436
1437 #if IDETAPE_DEBUG_LOG
1438 if (tape->debug_level >= 5)
1439 printk(KERN_INFO "ide-tape: rq_stack_index=%d\n",
1440 tape->rq_stack_index);
1441 #endif /* IDETAPE_DEBUG_LOG */
1442 if (tape->rq_stack_index == IDETAPE_PC_STACK)
1443 tape->rq_stack_index=0;
1444 return (&tape->rq_stack[tape->rq_stack_index++]);
1445 }
1446
1447 /*
1448 * idetape_init_pc initializes a packet command.
1449 */
1450 static void idetape_init_pc (idetape_pc_t *pc)
1451 {
1452 memset(pc->c, 0, 12);
1453 pc->retries = 0;
1454 pc->flags = 0;
1455 pc->request_transfer = 0;
1456 pc->buffer = pc->pc_buffer;
1457 pc->buffer_size = IDETAPE_PC_BUFFER_SIZE;
1458 pc->bh = NULL;
1459 pc->b_data = NULL;
1460 }
1461
1462 /*
1463 * idetape_analyze_error is called on each failed packet command retry
1464 * to analyze the request sense. We currently do not utilize this
1465 * information.
1466 */
1467 static void idetape_analyze_error (ide_drive_t *drive, idetape_request_sense_result_t *result)
1468 {
1469 idetape_tape_t *tape = drive->driver_data;
1470 idetape_pc_t *pc = tape->failed_pc;
1471
1472 tape->sense = *result;
1473 tape->sense_key = result->sense_key;
1474 tape->asc = result->asc;
1475 tape->ascq = result->ascq;
1476 #if IDETAPE_DEBUG_LOG
1477 /*
1478 * Without debugging, we only log an error if we decided to
1479 * give up retrying.
1480 */
1481 if (tape->debug_level >= 1)
1482 printk(KERN_INFO "ide-tape: pc = %x, sense key = %x, "
1483 "asc = %x, ascq = %x\n",
1484 pc->c[0], result->sense_key,
1485 result->asc, result->ascq);
1486 #endif /* IDETAPE_DEBUG_LOG */
1487
1488 /*
1489 * Correct pc->actually_transferred by asking the tape.
1490 */
1491 if (test_bit(PC_DMA_ERROR, &pc->flags)) {
1492 pc->actually_transferred = pc->request_transfer - tape->tape_block_size * ntohl(get_unaligned(&result->information));
1493 idetape_update_buffers(pc);
1494 }
1495
1496 /*
1497 * If error was the result of a zero-length read or write command,
1498 * with sense key=5, asc=0x22, ascq=0, let it slide. Some drives
1499 * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
1500 */
1501 if ((pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD)
1502 && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { /* length==0 */
1503 if (result->sense_key == 5) {
1504 /* don't report an error, everything's ok */
1505 pc->error = 0;
1506 /* don't retry read/write */
1507 set_bit(PC_ABORT, &pc->flags);
1508 }
1509 }
1510 if (pc->c[0] == IDETAPE_READ_CMD && result->filemark) {
1511 pc->error = IDETAPE_ERROR_FILEMARK;
1512 set_bit(PC_ABORT, &pc->flags);
1513 }
1514 if (pc->c[0] == IDETAPE_WRITE_CMD) {
1515 if (result->eom ||
1516 (result->sense_key == 0xd && result->asc == 0x0 &&
1517 result->ascq == 0x2)) {
1518 pc->error = IDETAPE_ERROR_EOD;
1519 set_bit(PC_ABORT, &pc->flags);
1520 }
1521 }
1522 if (pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD) {
1523 if (result->sense_key == 8) {
1524 pc->error = IDETAPE_ERROR_EOD;
1525 set_bit(PC_ABORT, &pc->flags);
1526 }
1527 if (!test_bit(PC_ABORT, &pc->flags) &&
1528 pc->actually_transferred)
1529 pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
1530 }
1531 }
1532
1533 /*
1534 * idetape_active_next_stage will declare the next stage as "active".
1535 */
1536 static void idetape_active_next_stage (ide_drive_t *drive)
1537 {
1538 idetape_tape_t *tape = drive->driver_data;
1539 idetape_stage_t *stage = tape->next_stage;
1540 struct request *rq = &stage->rq;
1541
1542 #if IDETAPE_DEBUG_LOG
1543 if (tape->debug_level >= 4)
1544 printk(KERN_INFO "ide-tape: Reached idetape_active_next_stage\n");
1545 #endif /* IDETAPE_DEBUG_LOG */
1546 #if IDETAPE_DEBUG_BUGS
1547 if (stage == NULL) {
1548 printk(KERN_ERR "ide-tape: bug: Trying to activate a non existing stage\n");
1549 return;
1550 }
1551 #endif /* IDETAPE_DEBUG_BUGS */
1552
1553 rq->rq_disk = tape->disk;
1554 rq->buffer = NULL;
1555 rq->special = (void *)stage->bh;
1556 tape->active_data_request = rq;
1557 tape->active_stage = stage;
1558 tape->next_stage = stage->next;
1559 }
1560
1561 /*
1562 * idetape_increase_max_pipeline_stages is a part of the feedback
1563 * loop which tries to find the optimum number of stages. In the
1564 * feedback loop, we are starting from a minimum maximum number of
1565 * stages, and if we sense that the pipeline is empty, we try to
1566 * increase it, until we reach the user compile time memory limit.
1567 */
1568 static void idetape_increase_max_pipeline_stages (ide_drive_t *drive)
1569 {
1570 idetape_tape_t *tape = drive->driver_data;
1571 int increase = (tape->max_pipeline - tape->min_pipeline) / 10;
1572
1573 #if IDETAPE_DEBUG_LOG
1574 if (tape->debug_level >= 4)
1575 printk (KERN_INFO "ide-tape: Reached idetape_increase_max_pipeline_stages\n");
1576 #endif /* IDETAPE_DEBUG_LOG */
1577
1578 tape->max_stages += max(increase, 1);
1579 tape->max_stages = max(tape->max_stages, tape->min_pipeline);
1580 tape->max_stages = min(tape->max_stages, tape->max_pipeline);
1581 }
1582
1583 /*
1584 * idetape_kfree_stage calls kfree to completely free a stage, along with
1585 * its related buffers.
1586 */
1587 static void __idetape_kfree_stage (idetape_stage_t *stage)
1588 {
1589 struct idetape_bh *prev_bh, *bh = stage->bh;
1590 int size;
1591
1592 while (bh != NULL) {
1593 if (bh->b_data != NULL) {
1594 size = (int) bh->b_size;
1595 while (size > 0) {
1596 free_page((unsigned long) bh->b_data);
1597 size -= PAGE_SIZE;
1598 bh->b_data += PAGE_SIZE;
1599 }
1600 }
1601 prev_bh = bh;
1602 bh = bh->b_reqnext;
1603 kfree(prev_bh);
1604 }
1605 kfree(stage);
1606 }
1607
1608 static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage)
1609 {
1610 __idetape_kfree_stage(stage);
1611 }
1612
1613 /*
1614 * idetape_remove_stage_head removes tape->first_stage from the pipeline.
1615 * The caller should avoid race conditions.
1616 */
1617 static void idetape_remove_stage_head (ide_drive_t *drive)
1618 {
1619 idetape_tape_t *tape = drive->driver_data;
1620 idetape_stage_t *stage;
1621
1622 #if IDETAPE_DEBUG_LOG
1623 if (tape->debug_level >= 4)
1624 printk(KERN_INFO "ide-tape: Reached idetape_remove_stage_head\n");
1625 #endif /* IDETAPE_DEBUG_LOG */
1626 #if IDETAPE_DEBUG_BUGS
1627 if (tape->first_stage == NULL) {
1628 printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n");
1629 return;
1630 }
1631 if (tape->active_stage == tape->first_stage) {
1632 printk(KERN_ERR "ide-tape: bug: Trying to free our active pipeline stage\n");
1633 return;
1634 }
1635 #endif /* IDETAPE_DEBUG_BUGS */
1636 stage = tape->first_stage;
1637 tape->first_stage = stage->next;
1638 idetape_kfree_stage(tape, stage);
1639 tape->nr_stages--;
1640 if (tape->first_stage == NULL) {
1641 tape->last_stage = NULL;
1642 #if IDETAPE_DEBUG_BUGS
1643 if (tape->next_stage != NULL)
1644 printk(KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n");
1645 if (tape->nr_stages)
1646 printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n");
1647 #endif /* IDETAPE_DEBUG_BUGS */
1648 }
1649 }
1650
1651 /*
1652 * This will free all the pipeline stages starting from new_last_stage->next
1653 * to the end of the list, and point tape->last_stage to new_last_stage.
1654 */
1655 static void idetape_abort_pipeline(ide_drive_t *drive,
1656 idetape_stage_t *new_last_stage)
1657 {
1658 idetape_tape_t *tape = drive->driver_data;
1659 idetape_stage_t *stage = new_last_stage->next;
1660 idetape_stage_t *nstage;
1661
1662 #if IDETAPE_DEBUG_LOG
1663 if (tape->debug_level >= 4)
1664 printk(KERN_INFO "ide-tape: %s: idetape_abort_pipeline called\n", tape->name);
1665 #endif
1666 while (stage) {
1667 nstage = stage->next;
1668 idetape_kfree_stage(tape, stage);
1669 --tape->nr_stages;
1670 --tape->nr_pending_stages;
1671 stage = nstage;
1672 }
1673 if (new_last_stage)
1674 new_last_stage->next = NULL;
1675 tape->last_stage = new_last_stage;
1676 tape->next_stage = NULL;
1677 }
1678
1679 /*
1680 * idetape_end_request is used to finish servicing a request, and to
1681 * insert a pending pipeline request into the main device queue.
1682 */
1683 static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
1684 {
1685 struct request *rq = HWGROUP(drive)->rq;
1686 idetape_tape_t *tape = drive->driver_data;
1687 unsigned long flags;
1688 int error;
1689 int remove_stage = 0;
1690 idetape_stage_t *active_stage;
1691
1692 #if IDETAPE_DEBUG_LOG
1693 if (tape->debug_level >= 4)
1694 printk(KERN_INFO "ide-tape: Reached idetape_end_request\n");
1695 #endif /* IDETAPE_DEBUG_LOG */
1696
1697 switch (uptodate) {
1698 case 0: error = IDETAPE_ERROR_GENERAL; break;
1699 case 1: error = 0; break;
1700 default: error = uptodate;
1701 }
1702 rq->errors = error;
1703 if (error)
1704 tape->failed_pc = NULL;
1705
1706 spin_lock_irqsave(&tape->spinlock, flags);
1707
1708 /* The request was a pipelined data transfer request */
1709 if (tape->active_data_request == rq) {
1710 active_stage = tape->active_stage;
1711 tape->active_stage = NULL;
1712 tape->active_data_request = NULL;
1713 tape->nr_pending_stages--;
1714 if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
1715 remove_stage = 1;
1716 if (error) {
1717 set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
1718 if (error == IDETAPE_ERROR_EOD)
1719 idetape_abort_pipeline(drive, active_stage);
1720 }
1721 } else if (rq->cmd[0] & REQ_IDETAPE_READ) {
1722 if (error == IDETAPE_ERROR_EOD) {
1723 set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
1724 idetape_abort_pipeline(drive, active_stage);
1725 }
1726 }
1727 if (tape->next_stage != NULL) {
1728 idetape_active_next_stage(drive);
1729
1730 /*
1731 * Insert the next request into the request queue.
1732 */
1733 (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
1734 } else if (!error) {
1735 idetape_increase_max_pipeline_stages(drive);
1736 }
1737 }
1738 ide_end_drive_cmd(drive, 0, 0);
1739 // blkdev_dequeue_request(rq);
1740 // drive->rq = NULL;
1741 // end_that_request_last(rq);
1742
1743 if (remove_stage)
1744 idetape_remove_stage_head(drive);
1745 if (tape->active_data_request == NULL)
1746 clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
1747 spin_unlock_irqrestore(&tape->spinlock, flags);
1748 return 0;
1749 }
1750
1751 static ide_startstop_t idetape_request_sense_callback (ide_drive_t *drive)
1752 {
1753 idetape_tape_t *tape = drive->driver_data;
1754
1755 #if IDETAPE_DEBUG_LOG
1756 if (tape->debug_level >= 4)
1757 printk(KERN_INFO "ide-tape: Reached idetape_request_sense_callback\n");
1758 #endif /* IDETAPE_DEBUG_LOG */
1759 if (!tape->pc->error) {
1760 idetape_analyze_error(drive, (idetape_request_sense_result_t *) tape->pc->buffer);
1761 idetape_end_request(drive, 1, 0);
1762 } else {
1763 printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - Aborting request!\n");
1764 idetape_end_request(drive, 0, 0);
1765 }
1766 return ide_stopped;
1767 }
1768
1769 static void idetape_create_request_sense_cmd (idetape_pc_t *pc)
1770 {
1771 idetape_init_pc(pc);
1772 pc->c[0] = IDETAPE_REQUEST_SENSE_CMD;
1773 pc->c[4] = 20;
1774 pc->request_transfer = 20;
1775 pc->callback = &idetape_request_sense_callback;
1776 }
1777
1778 static void idetape_init_rq(struct request *rq, u8 cmd)
1779 {
1780 memset(rq, 0, sizeof(*rq));
1781 rq->flags = REQ_SPECIAL;
1782 rq->cmd[0] = cmd;
1783 }
1784
1785 /*
1786 * idetape_queue_pc_head generates a new packet command request in front
1787 * of the request queue, before the current request, so that it will be
1788 * processed immediately, on the next pass through the driver.
1789 *
1790 * idetape_queue_pc_head is called from the request handling part of
1791 * the driver (the "bottom" part). Safe storage for the request should
1792 * be allocated with idetape_next_pc_storage and idetape_next_rq_storage
1793 * before calling idetape_queue_pc_head.
1794 *
1795 * Memory for those requests is pre-allocated at initialization time, and
1796 * is limited to IDETAPE_PC_STACK requests. We assume that we have enough
1797 * space for the maximum possible number of inter-dependent packet commands.
1798 *
1799 * The higher level of the driver - The ioctl handler and the character
1800 * device handling functions should queue request to the lower level part
1801 * and wait for their completion using idetape_queue_pc_tail or
1802 * idetape_queue_rw_tail.
1803 */
1804 static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct request *rq)
1805 {
1806 struct ide_tape_obj *tape = drive->driver_data;
1807
1808 idetape_init_rq(rq, REQ_IDETAPE_PC1);
1809 rq->buffer = (char *) pc;
1810 rq->rq_disk = tape->disk;
1811 (void) ide_do_drive_cmd(drive, rq, ide_preempt);
1812 }
1813
1814 /*
1815 * idetape_retry_pc is called when an error was detected during the
1816 * last packet command. We queue a request sense packet command in
1817 * the head of the request list.
1818 */
1819 static ide_startstop_t idetape_retry_pc (ide_drive_t *drive)
1820 {
1821 idetape_tape_t *tape = drive->driver_data;
1822 idetape_pc_t *pc;
1823 struct request *rq;
1824 atapi_error_t error;
1825
1826 error.all = HWIF(drive)->INB(IDE_ERROR_REG);
1827 pc = idetape_next_pc_storage(drive);
1828 rq = idetape_next_rq_storage(drive);
1829 idetape_create_request_sense_cmd(pc);
1830 set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
1831 idetape_queue_pc_head(drive, pc, rq);
1832 return ide_stopped;
1833 }
1834
1835 /*
1836 * idetape_postpone_request postpones the current request so that
1837 * ide.c will be able to service requests from another device on
1838 * the same hwgroup while we are polling for DSC.
1839 */
1840 static void idetape_postpone_request (ide_drive_t *drive)
1841 {
1842 idetape_tape_t *tape = drive->driver_data;
1843
1844 #if IDETAPE_DEBUG_LOG
1845 if (tape->debug_level >= 4)
1846 printk(KERN_INFO "ide-tape: idetape_postpone_request\n");
1847 #endif
1848 tape->postponed_rq = HWGROUP(drive)->rq;
1849 ide_stall_queue(drive, tape->dsc_polling_frequency);
1850 }
1851
1852 /*
1853 * idetape_pc_intr is the usual interrupt handler which will be called
1854 * during a packet command. We will transfer some of the data (as
1855 * requested by the drive) and will re-point interrupt handler to us.
1856 * When data transfer is finished, we will act according to the
1857 * algorithm described before idetape_issue_packet_command.
1858 *
1859 */
1860 static ide_startstop_t idetape_pc_intr (ide_drive_t *drive)
1861 {
1862 ide_hwif_t *hwif = drive->hwif;
1863 idetape_tape_t *tape = drive->driver_data;
1864 atapi_status_t status;
1865 atapi_bcount_t bcount;
1866 atapi_ireason_t ireason;
1867 idetape_pc_t *pc = tape->pc;
1868
1869 unsigned int temp;
1870 #if SIMULATE_ERRORS
1871 static int error_sim_count = 0;
1872 #endif
1873
1874 #if IDETAPE_DEBUG_LOG
1875 if (tape->debug_level >= 4)
1876 printk(KERN_INFO "ide-tape: Reached idetape_pc_intr "
1877 "interrupt handler\n");
1878 #endif /* IDETAPE_DEBUG_LOG */
1879
1880 /* Clear the interrupt */
1881 status.all = HWIF(drive)->INB(IDE_STATUS_REG);
1882
1883 if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
1884 if (HWIF(drive)->ide_dma_end(drive) || status.b.check) {
1885 /*
1886 * A DMA error is sometimes expected. For example,
1887 * if the tape is crossing a filemark during a
1888 * READ command, it will issue an irq and position
1889 * itself before the filemark, so that only a partial
1890 * data transfer will occur (which causes the DMA
1891 * error). In that case, we will later ask the tape
1892 * how much bytes of the original request were
1893 * actually transferred (we can't receive that
1894 * information from the DMA engine on most chipsets).
1895 */
1896
1897 /*
1898 * On the contrary, a DMA error is never expected;
1899 * it usually indicates a hardware error or abort.
1900 * If the tape crosses a filemark during a READ
1901 * command, it will issue an irq and position itself
1902 * after the filemark (not before). Only a partial
1903 * data transfer will occur, but no DMA error.
1904 * (AS, 19 Apr 2001)
1905 */
1906 set_bit(PC_DMA_ERROR, &pc->flags);
1907 } else {
1908 pc->actually_transferred = pc->request_transfer;
1909 idetape_update_buffers(pc);
1910 }
1911 #if IDETAPE_DEBUG_LOG
1912 if (tape->debug_level >= 4)
1913 printk(KERN_INFO "ide-tape: DMA finished\n");
1914 #endif /* IDETAPE_DEBUG_LOG */
1915 }
1916
1917 /* No more interrupts */
1918 if (!status.b.drq) {
1919 #if IDETAPE_DEBUG_LOG
1920 if (tape->debug_level >= 2)
1921 printk(KERN_INFO "ide-tape: Packet command completed, %d bytes transferred\n", pc->actually_transferred);
1922 #endif /* IDETAPE_DEBUG_LOG */
1923 clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
1924
1925 local_irq_enable();
1926
1927 #if SIMULATE_ERRORS
1928 if ((pc->c[0] == IDETAPE_WRITE_CMD ||
1929 pc->c[0] == IDETAPE_READ_CMD) &&
1930 (++error_sim_count % 100) == 0) {
1931 printk(KERN_INFO "ide-tape: %s: simulating error\n",
1932 tape->name);
1933 status.b.check = 1;
1934 }
1935 #endif
1936 if (status.b.check && pc->c[0] == IDETAPE_REQUEST_SENSE_CMD)
1937 status.b.check = 0;
1938 if (status.b.check || test_bit(PC_DMA_ERROR, &pc->flags)) { /* Error detected */
1939 #if IDETAPE_DEBUG_LOG
1940 if (tape->debug_level >= 1)
1941 printk(KERN_INFO "ide-tape: %s: I/O error\n",
1942 tape->name);
1943 #endif /* IDETAPE_DEBUG_LOG */
1944 if (pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
1945 printk(KERN_ERR "ide-tape: I/O error in request sense command\n");
1946 return ide_do_reset(drive);
1947 }
1948 #if IDETAPE_DEBUG_LOG
1949 if (tape->debug_level >= 1)
1950 printk(KERN_INFO "ide-tape: [cmd %x]: check condition\n", pc->c[0]);
1951 #endif
1952 /* Retry operation */
1953 return idetape_retry_pc(drive);
1954 }
1955 pc->error = 0;
1956 if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
1957 !status.b.dsc) {
1958 /* Media access command */
1959 tape->dsc_polling_start = jiffies;
1960 tape->dsc_polling_frequency = IDETAPE_DSC_MA_FAST;
1961 tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
1962 /* Allow ide.c to handle other requests */
1963 idetape_postpone_request(drive);
1964 return ide_stopped;
1965 }
1966 if (tape->failed_pc == pc)
1967 tape->failed_pc = NULL;
1968 /* Command finished - Call the callback function */
1969 return pc->callback(drive);
1970 }
1971 if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
1972 printk(KERN_ERR "ide-tape: The tape wants to issue more "
1973 "interrupts in DMA mode\n");
1974 printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
1975 (void)__ide_dma_off(drive);
1976 return ide_do_reset(drive);
1977 }
1978 /* Get the number of bytes to transfer on this interrupt. */
1979 bcount.b.high = hwif->INB(IDE_BCOUNTH_REG);
1980 bcount.b.low = hwif->INB(IDE_BCOUNTL_REG);
1981
1982 ireason.all = hwif->INB(IDE_IREASON_REG);
1983
1984 if (ireason.b.cod) {
1985 printk(KERN_ERR "ide-tape: CoD != 0 in idetape_pc_intr\n");
1986 return ide_do_reset(drive);
1987 }
1988 if (ireason.b.io == test_bit(PC_WRITING, &pc->flags)) {
1989 /* Hopefully, we will never get here */
1990 printk(KERN_ERR "ide-tape: We wanted to %s, ",
1991 ireason.b.io ? "Write":"Read");
1992 printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n",
1993 ireason.b.io ? "Read":"Write");
1994 return ide_do_reset(drive);
1995 }
1996 if (!test_bit(PC_WRITING, &pc->flags)) {
1997 /* Reading - Check that we have enough space */
1998 temp = pc->actually_transferred + bcount.all;
1999 if (temp > pc->request_transfer) {
2000 if (temp > pc->buffer_size) {
2001 printk(KERN_ERR "ide-tape: The tape wants to send us more data than expected - discarding data\n");
2002 idetape_discard_data(drive, bcount.all);
2003 ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
2004 return ide_started;
2005 }
2006 #if IDETAPE_DEBUG_LOG
2007 if (tape->debug_level >= 2)
2008 printk(KERN_NOTICE "ide-tape: The tape wants to send us more data than expected - allowing transfer\n");
2009 #endif /* IDETAPE_DEBUG_LOG */
2010 }
2011 }
2012 if (test_bit(PC_WRITING, &pc->flags)) {
2013 if (pc->bh != NULL)
2014 idetape_output_buffers(drive, pc, bcount.all);
2015 else
2016 /* Write the current buffer */
2017 HWIF(drive)->atapi_output_bytes(drive, pc->current_position, bcount.all);
2018 } else {
2019 if (pc->bh != NULL)
2020 idetape_input_buffers(drive, pc, bcount.all);
2021 else
2022 /* Read the current buffer */
2023 HWIF(drive)->atapi_input_bytes(drive, pc->current_position, bcount.all);
2024 }
2025 /* Update the current position */
2026 pc->actually_transferred += bcount.all;
2027 pc->current_position += bcount.all;
2028 #if IDETAPE_DEBUG_LOG
2029 if (tape->debug_level >= 2)
2030 printk(KERN_INFO "ide-tape: [cmd %x] transferred %d bytes on that interrupt\n", pc->c[0], bcount.all);
2031 #endif
2032 /* And set the interrupt handler again */
2033 ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
2034 return ide_started;
2035 }
2036
2037 /*
2038 * Packet Command Interface
2039 *
2040 * The current Packet Command is available in tape->pc, and will not
2041 * change until we finish handling it. Each packet command is associated
2042 * with a callback function that will be called when the command is
2043 * finished.
2044 *
2045 * The handling will be done in three stages:
2046 *
2047 * 1. idetape_issue_packet_command will send the packet command to the
2048 * drive, and will set the interrupt handler to idetape_pc_intr.
2049 *
2050 * 2. On each interrupt, idetape_pc_intr will be called. This step
2051 * will be repeated until the device signals us that no more
2052 * interrupts will be issued.
2053 *
2054 * 3. ATAPI Tape media access commands have immediate status with a
2055 * delayed process. In case of a successful initiation of a
2056 * media access packet command, the DSC bit will be set when the
2057 * actual execution of the command is finished.
2058 * Since the tape drive will not issue an interrupt, we have to
2059 * poll for this event. In this case, we define the request as
2060 * "low priority request" by setting rq_status to
2061 * IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and exit
2062 * the driver.
2063 *
2064 * ide.c will then give higher priority to requests which
2065 * originate from the other device, until will change rq_status
2066 * to RQ_ACTIVE.
2067 *
2068 * 4. When the packet command is finished, it will be checked for errors.
2069 *
2070 * 5. In case an error was found, we queue a request sense packet
2071 * command in front of the request queue and retry the operation
2072 * up to IDETAPE_MAX_PC_RETRIES times.
2073 *
2074 * 6. In case no error was found, or we decided to give up and not
2075 * to retry again, the callback function will be called and then
2076 * we will handle the next request.
2077 *
2078 */
2079 static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
2080 {
2081 ide_hwif_t *hwif = drive->hwif;
2082 idetape_tape_t *tape = drive->driver_data;
2083 idetape_pc_t *pc = tape->pc;
2084 atapi_ireason_t ireason;
2085 int retries = 100;
2086 ide_startstop_t startstop;
2087
2088 if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
2089 printk(KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n");
2090 return startstop;
2091 }
2092 ireason.all = hwif->INB(IDE_IREASON_REG);
2093 while (retries-- && (!ireason.b.cod || ireason.b.io)) {
2094 printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing "
2095 "a packet command, retrying\n");
2096 udelay(100);
2097 ireason.all = hwif->INB(IDE_IREASON_REG);
2098 if (retries == 0) {
2099 printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while "
2100 "issuing a packet command, ignoring\n");
2101 ireason.b.cod = 1;
2102 ireason.b.io = 0;
2103 }
2104 }
2105 if (!ireason.b.cod || ireason.b.io) {
2106 printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing "
2107 "a packet command\n");
2108 return ide_do_reset(drive);
2109 }
2110 /* Set the interrupt routine */
2111 ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
2112 #ifdef CONFIG_BLK_DEV_IDEDMA
2113 /* Begin DMA, if necessary */
2114 if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags))
2115 hwif->dma_start(drive);
2116 #endif
2117 /* Send the actual packet */
2118 HWIF(drive)->atapi_output_bytes(drive, pc->c, 12);
2119 return ide_started;
2120 }
2121
2122 static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape_pc_t *pc)
2123 {
2124 ide_hwif_t *hwif = drive->hwif;
2125 idetape_tape_t *tape = drive->driver_data;
2126 atapi_bcount_t bcount;
2127 int dma_ok = 0;
2128
2129 #if IDETAPE_DEBUG_BUGS
2130 if (tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD &&
2131 pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
2132 printk(KERN_ERR "ide-tape: possible ide-tape.c bug - "
2133 "Two request sense in serial were issued\n");
2134 }
2135 #endif /* IDETAPE_DEBUG_BUGS */
2136
2137 if (tape->failed_pc == NULL && pc->c[0] != IDETAPE_REQUEST_SENSE_CMD)
2138 tape->failed_pc = pc;
2139 /* Set the current packet command */
2140 tape->pc = pc;
2141
2142 if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
2143 test_bit(PC_ABORT, &pc->flags)) {
2144 /*
2145 * We will "abort" retrying a packet command in case
2146 * a legitimate error code was received (crossing a
2147 * filemark, or end of the media, for example).
2148 */
2149 if (!test_bit(PC_ABORT, &pc->flags)) {
2150 if (!(pc->c[0] == IDETAPE_TEST_UNIT_READY_CMD &&
2151 tape->sense_key == 2 && tape->asc == 4 &&
2152 (tape->ascq == 1 || tape->ascq == 8))) {
2153 printk(KERN_ERR "ide-tape: %s: I/O error, "
2154 "pc = %2x, key = %2x, "
2155 "asc = %2x, ascq = %2x\n",
2156 tape->name, pc->c[0],
2157 tape->sense_key, tape->asc,
2158 tape->ascq);
2159 }
2160 /* Giving up */
2161 pc->error = IDETAPE_ERROR_GENERAL;
2162 }
2163 tape->failed_pc = NULL;
2164 return pc->callback(drive);
2165 }
2166 #if IDETAPE_DEBUG_LOG
2167 if (tape->debug_level >= 2)
2168 printk(KERN_INFO "ide-tape: Retry number - %d, cmd = %02X\n", pc->retries, pc->c[0]);
2169 #endif /* IDETAPE_DEBUG_LOG */
2170
2171 pc->retries++;
2172 /* We haven't transferred any data yet */
2173 pc->actually_transferred = 0;
2174 pc->current_position = pc->buffer;
2175 /* Request to transfer the entire buffer at once */
2176 bcount.all = pc->request_transfer;
2177
2178 if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) {
2179 printk(KERN_WARNING "ide-tape: DMA disabled, "
2180 "reverting to PIO\n");
2181 (void)__ide_dma_off(drive);
2182 }
2183 if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma)
2184 dma_ok = !hwif->dma_setup(drive);
2185
2186 if (IDE_CONTROL_REG)
2187 hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
2188 hwif->OUTB(dma_ok ? 1 : 0, IDE_FEATURE_REG); /* Use PIO/DMA */
2189 hwif->OUTB(bcount.b.high, IDE_BCOUNTH_REG);
2190 hwif->OUTB(bcount.b.low, IDE_BCOUNTL_REG);
2191 hwif->OUTB(drive->select.all, IDE_SELECT_REG);
2192 if (dma_ok) /* Will begin DMA later */
2193 set_bit(PC_DMA_IN_PROGRESS, &pc->flags);
2194 if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) {
2195 ide_set_handler(drive, &idetape_transfer_pc, IDETAPE_WAIT_CMD, NULL);
2196 hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
2197 return ide_started;
2198 } else {
2199 hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
2200 return idetape_transfer_pc(drive);
2201 }
2202 }
2203
2204 /*
2205 * General packet command callback function.
2206 */
2207 static ide_startstop_t idetape_pc_callback (ide_drive_t *drive)
2208 {
2209 idetape_tape_t *tape = drive->driver_data;
2210
2211 #if IDETAPE_DEBUG_LOG
2212 if (tape->debug_level >= 4)
2213 printk(KERN_INFO "ide-tape: Reached idetape_pc_callback\n");
2214 #endif /* IDETAPE_DEBUG_LOG */
2215
2216 idetape_end_request(drive, tape->pc->error ? 0 : 1, 0);
2217 return ide_stopped;
2218 }
2219
2220 /*
2221 * A mode sense command is used to "sense" tape parameters.
2222 */
2223 static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code)
2224 {
2225 idetape_init_pc(pc);
2226 pc->c[0] = IDETAPE_MODE_SENSE_CMD;
2227 if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
2228 pc->c[1] = 8; /* DBD = 1 - Don't return block descriptors */
2229 pc->c[2] = page_code;
2230 /*
2231 * Changed pc->c[3] to 0 (255 will at best return unused info).
2232 *
2233 * For SCSI this byte is defined as subpage instead of high byte
2234 * of length and some IDE drives seem to interpret it this way
2235 * and return an error when 255 is used.
2236 */
2237 pc->c[3] = 0;
2238 pc->c[4] = 255; /* (We will just discard data in that case) */
2239 if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
2240 pc->request_transfer = 12;
2241 else if (page_code == IDETAPE_CAPABILITIES_PAGE)
2242 pc->request_transfer = 24;
2243 else
2244 pc->request_transfer = 50;
2245 pc->callback = &idetape_pc_callback;
2246 }
2247
2248 static void calculate_speeds(ide_drive_t *drive)
2249 {
2250 idetape_tape_t *tape = drive->driver_data;
2251 int full = 125, empty = 75;
2252
2253 if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) {
2254 tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head;
2255 tape->controlled_previous_head_time = tape->controlled_pipeline_head_time;
2256 tape->controlled_last_pipeline_head = tape->pipeline_head;
2257 tape->controlled_pipeline_head_time = jiffies;
2258 }
2259 if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
2260 tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time);
2261 else if (time_after(jiffies, tape->controlled_previous_head_time))
2262 tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time);
2263
2264 if (tape->nr_pending_stages < tape->max_stages /*- 1 */) {
2265 /* -1 for read mode error recovery */
2266 if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) {
2267 tape->uncontrolled_pipeline_head_time = jiffies;
2268 tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time);
2269 }
2270 } else {
2271 tape->uncontrolled_previous_head_time = jiffies;
2272 tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
2273 if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) {
2274 tape->uncontrolled_pipeline_head_time = jiffies;
2275 }
2276 }
2277 tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed);
2278 if (tape->speed_control == 0) {
2279 tape->max_insert_speed = 5000;
2280 } else if (tape->speed_control == 1) {
2281 if (tape->nr_pending_stages >= tape->max_stages / 2)
2282 tape->max_insert_speed = tape->pipeline_head_speed +
2283 (1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages;
2284 else
2285 tape->max_insert_speed = 500 +
2286 (tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages;
2287 if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
2288 tape->max_insert_speed = 5000;
2289 } else if (tape->speed_control == 2) {
2290 tape->max_insert_speed = tape->pipeline_head_speed * empty / 100 +
2291 (tape->pipeline_head_speed * full / 100 - tape->pipeline_head_speed * empty / 100) * tape->nr_pending_stages / tape->max_stages;
2292 } else
2293 tape->max_insert_speed = tape->speed_control;
2294 tape->max_insert_speed = max(tape->max_insert_speed, 500);
2295 }
2296
2297 static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive)
2298 {
2299 idetape_tape_t *tape = drive->driver_data;
2300 idetape_pc_t *pc = tape->pc;
2301 atapi_status_t status;
2302
2303 status.all = HWIF(drive)->INB(IDE_STATUS_REG);
2304 if (status.b.dsc) {
2305 if (status.b.check) {
2306 /* Error detected */
2307 if (pc->c[0] != IDETAPE_TEST_UNIT_READY_CMD)
2308 printk(KERN_ERR "ide-tape: %s: I/O error, ",
2309 tape->name);
2310 /* Retry operation */
2311 return idetape_retry_pc(drive);
2312 }
2313 pc->error = 0;
2314 if (tape->failed_pc == pc)
2315 tape->failed_pc = NULL;
2316 } else {
2317 pc->error = IDETAPE_ERROR_GENERAL;
2318 tape->failed_pc = NULL;
2319 }
2320 return pc->callback(drive);
2321 }
2322
2323 static ide_startstop_t idetape_rw_callback (ide_drive_t *drive)
2324 {
2325 idetape_tape_t *tape = drive->driver_data;
2326 struct request *rq = HWGROUP(drive)->rq;
2327 int blocks = tape->pc->actually_transferred / tape->tape_block_size;
2328
2329 tape->avg_size += blocks * tape->tape_block_size;
2330 tape->insert_size += blocks * tape->tape_block_size;
2331 if (tape->insert_size > 1024 * 1024)
2332 tape->measure_insert_time = 1;
2333 if (tape->measure_insert_time) {
2334 tape->measure_insert_time = 0;
2335 tape->insert_time = jiffies;
2336 tape->insert_size = 0;
2337 }
2338 if (time_after(jiffies, tape->insert_time))
2339 tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
2340 if (time_after_eq(jiffies, tape->avg_time + HZ)) {
2341 tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024;
2342 tape->avg_size = 0;
2343 tape->avg_time = jiffies;
2344 }
2345
2346 #if IDETAPE_DEBUG_LOG
2347 if (tape->debug_level >= 4)
2348 printk(KERN_INFO "ide-tape: Reached idetape_rw_callback\n");
2349 #endif /* IDETAPE_DEBUG_LOG */
2350
2351 tape->first_frame_position += blocks;
2352 rq->current_nr_sectors -= blocks;
2353
2354 if (!tape->pc->error)
2355 idetape_end_request(drive, 1, 0);
2356 else
2357 idetape_end_request(drive, tape->pc->error, 0);
2358 return ide_stopped;
2359 }
2360
2361 static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
2362 {
2363 idetape_init_pc(pc);
2364 pc->c[0] = IDETAPE_READ_CMD;
2365 put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
2366 pc->c[1] = 1;
2367 pc->callback = &idetape_rw_callback;
2368 pc->bh = bh;
2369 atomic_set(&bh->b_count, 0);
2370 pc->buffer = NULL;
2371 pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
2372 if (pc->request_transfer == tape->stage_size)
2373 set_bit(PC_DMA_RECOMMENDED, &pc->flags);
2374 }
2375
2376 static void idetape_create_read_buffer_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
2377 {
2378 int size = 32768;
2379 struct idetape_bh *p = bh;
2380
2381 idetape_init_pc(pc);
2382 pc->c[0] = IDETAPE_READ_BUFFER_CMD;
2383 pc->c[1] = IDETAPE_RETRIEVE_FAULTY_BLOCK;
2384 pc->c[7] = size >> 8;
2385 pc->c[8] = size & 0xff;
2386 pc->callback = &idetape_pc_callback;
2387 pc->bh = bh;
2388 atomic_set(&bh->b_count, 0);
2389 pc->buffer = NULL;
2390 while (p) {
2391 atomic_set(&p->b_count, 0);
2392 p = p->b_reqnext;
2393 }
2394 pc->request_transfer = pc->buffer_size = size;
2395 }
2396
2397 static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
2398 {
2399 idetape_init_pc(pc);
2400 pc->c[0] = IDETAPE_WRITE_CMD;
2401 put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
2402 pc->c[1] = 1;
2403 pc->callback = &idetape_rw_callback;
2404 set_bit(PC_WRITING, &pc->flags);
2405 pc->bh = bh;
2406 pc->b_data = bh->b_data;
2407 pc->b_count = atomic_read(&bh->b_count);
2408 pc->buffer = NULL;
2409 pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
2410 if (pc->request_transfer == tape->stage_size)
2411 set_bit(PC_DMA_RECOMMENDED, &pc->flags);
2412 }
2413
2414 /*
2415 * idetape_do_request is our request handling function.
2416 */
2417 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
2418 struct request *rq, sector_t block)
2419 {
2420 idetape_tape_t *tape = drive->driver_data;
2421 idetape_pc_t *pc = NULL;
2422 struct request *postponed_rq = tape->postponed_rq;
2423 atapi_status_t status;
2424
2425 #if IDETAPE_DEBUG_LOG
2426 #if 0
2427 if (tape->debug_level >= 5)
2428 printk(KERN_INFO "ide-tape: rq_status: %d, "
2429 "dev: %s, cmd: %ld, errors: %d\n", rq->rq_status,
2430 rq->rq_disk->disk_name, rq->cmd[0], rq->errors);
2431 #endif
2432 if (tape->debug_level >= 2)
2433 printk(KERN_INFO "ide-tape: sector: %ld, "
2434 "nr_sectors: %ld, current_nr_sectors: %d\n",
2435 rq->sector, rq->nr_sectors, rq->current_nr_sectors);
2436 #endif /* IDETAPE_DEBUG_LOG */
2437
2438 if ((rq->flags & REQ_SPECIAL) == 0) {
2439 /*
2440 * We do not support buffer cache originated requests.
2441 */
2442 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
2443 "request queue (%ld)\n", drive->name, rq->flags);
2444 ide_end_request(drive, 0, 0);
2445 return ide_stopped;
2446 }
2447
2448 /*
2449 * Retry a failed packet command
2450 */
2451 if (tape->failed_pc != NULL &&
2452 tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
2453 return idetape_issue_packet_command(drive, tape->failed_pc);
2454 }
2455 #if IDETAPE_DEBUG_BUGS
2456 if (postponed_rq != NULL)
2457 if (rq != postponed_rq) {
2458 printk(KERN_ERR "ide-tape: ide-tape.c bug - "
2459 "Two DSC requests were queued\n");
2460 idetape_end_request(drive, 0, 0);
2461 return ide_stopped;
2462 }
2463 #endif /* IDETAPE_DEBUG_BUGS */
2464
2465 tape->postponed_rq = NULL;
2466
2467 /*
2468 * If the tape is still busy, postpone our request and service
2469 * the other device meanwhile.
2470 */
2471 status.all = HWIF(drive)->INB(IDE_STATUS_REG);
2472
2473 if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2))
2474 set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
2475
2476 if (drive->post_reset == 1) {
2477 set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
2478 drive->post_reset = 0;
2479 }
2480
2481 if (tape->tape_still_time > 100 && tape->tape_still_time < 200)
2482 tape->measure_insert_time = 1;
2483 if (time_after(jiffies, tape->insert_time))
2484 tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
2485 calculate_speeds(drive);
2486 if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) &&
2487 !status.b.dsc) {
2488 if (postponed_rq == NULL) {
2489 tape->dsc_polling_start = jiffies;
2490 tape->dsc_polling_frequency = tape->best_dsc_rw_frequency;
2491 tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
2492 } else if (time_after(jiffies, tape->dsc_timeout)) {
2493 printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
2494 tape->name);
2495 if (rq->cmd[0] & REQ_IDETAPE_PC2) {
2496 idetape_media_access_finished(drive);
2497 return ide_stopped;
2498 } else {
2499 return ide_do_reset(drive);
2500 }
2501 } else if (time_after(jiffies, tape->dsc_polling_start + IDETAPE_DSC_MA_THRESHOLD))
2502 tape->dsc_polling_frequency = IDETAPE_DSC_MA_SLOW;
2503 idetape_postpone_request(drive);
2504 return ide_stopped;
2505 }
2506 if (rq->cmd[0] & REQ_IDETAPE_READ) {
2507 tape->buffer_head++;
2508 #if USE_IOTRACE
2509 IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
2510 #endif
2511 tape->postpone_cnt = 0;
2512 pc = idetape_next_pc_storage(drive);
2513 idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
2514 goto out;
2515 }
2516 if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
2517 tape->buffer_head++;
2518 #if USE_IOTRACE
2519 IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
2520 #endif
2521 tape->postpone_cnt = 0;
2522 pc = idetape_next_pc_storage(drive);
2523 idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
2524 goto out;
2525 }
2526 if (rq->cmd[0] & REQ_IDETAPE_READ_BUFFER) {
2527 tape->postpone_cnt = 0;
2528 pc = idetape_next_pc_storage(drive);
2529 idetape_create_read_buffer_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
2530 goto out;
2531 }
2532 if (rq->cmd[0] & REQ_IDETAPE_PC1) {
2533 pc = (idetape_pc_t *) rq->buffer;
2534 rq->cmd[0] &= ~(REQ_IDETAPE_PC1);
2535 rq->cmd[0] |= REQ_IDETAPE_PC2;
2536 goto out;
2537 }
2538 if (rq->cmd[0] & REQ_IDETAPE_PC2) {
2539 idetape_media_access_finished(drive);
2540 return ide_stopped;
2541 }
2542 BUG();
2543 out:
2544 return idetape_issue_packet_command(drive, pc);
2545 }
2546
2547 /*
2548 * Pipeline related functions
2549 */
2550 static inline int idetape_pipeline_active (idetape_tape_t *tape)
2551 {
2552 int rc1, rc2;
2553
2554 rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
2555 rc2 = (tape->active_data_request != NULL);
2556 return rc1;
2557 }
2558
2559 /*
2560 * idetape_kmalloc_stage uses __get_free_page to allocate a pipeline
2561 * stage, along with all the necessary small buffers which together make
2562 * a buffer of size tape->stage_size (or a bit more). We attempt to
2563 * combine sequential pages as much as possible.
2564 *
2565 * Returns a pointer to the new allocated stage, or NULL if we
2566 * can't (or don't want to) allocate a stage.
2567 *
2568 * Pipeline stages are optional and are used to increase performance.
2569 * If we can't allocate them, we'll manage without them.
2570 */
2571 static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape, int full, int clear)
2572 {
2573 idetape_stage_t *stage;
2574 struct idetape_bh *prev_bh, *bh;
2575 int pages = tape->pages_per_stage;
2576 char *b_data = NULL;
2577
2578 if ((stage = (idetape_stage_t *) kmalloc (sizeof (idetape_stage_t),GFP_KERNEL)) == NULL)
2579 return NULL;
2580 stage->next = NULL;
2581
2582 bh = stage->bh = (struct idetape_bh *)kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
2583 if (bh == NULL)
2584 goto abort;
2585 bh->b_reqnext = NULL;
2586 if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
2587 goto abort;
2588 if (clear)
2589 memset(bh->b_data, 0, PAGE_SIZE);
2590 bh->b_size = PAGE_SIZE;
2591 atomic_set(&bh->b_count, full ? bh->b_size : 0);
2592
2593 while (--pages) {
2594 if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
2595 goto abort;
2596 if (clear)
2597 memset(b_data, 0, PAGE_SIZE);
2598 if (bh->b_data == b_data + PAGE_SIZE) {
2599 bh->b_size += PAGE_SIZE;
2600 bh->b_data -= PAGE_SIZE;
2601 if (full)
2602 atomic_add(PAGE_SIZE, &bh->b_count);
2603 continue;
2604 }
2605 if (b_data == bh->b_data + bh->b_size) {
2606 bh->b_size += PAGE_SIZE;
2607 if (full)
2608 atomic_add(PAGE_SIZE, &bh->b_count);
2609 continue;
2610 }
2611 prev_bh = bh;
2612 if ((bh = (struct idetape_bh *)kmalloc(sizeof(struct idetape_bh), GFP_KERNEL)) == NULL) {
2613 free_page((unsigned long) b_data);
2614 goto abort;
2615 }
2616 bh->b_reqnext = NULL;
2617 bh->b_data = b_data;
2618 bh->b_size = PAGE_SIZE;
2619 atomic_set(&bh->b_count, full ? bh->b_size : 0);
2620 prev_bh->b_reqnext = bh;
2621 }
2622 bh->b_size -= tape->excess_bh_size;
2623 if (full)
2624 atomic_sub(tape->excess_bh_size, &bh->b_count);
2625 return stage;
2626 abort:
2627 __idetape_kfree_stage(stage);
2628 return NULL;
2629 }
2630
2631 static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape)
2632 {
2633 idetape_stage_t *cache_stage = tape->cache_stage;
2634
2635 #if IDETAPE_DEBUG_LOG
2636 if (tape->debug_level >= 4)
2637 printk(KERN_INFO "ide-tape: Reached idetape_kmalloc_stage\n");
2638 #endif /* IDETAPE_DEBUG_LOG */
2639
2640 if (tape->nr_stages >= tape->max_stages)
2641 return NULL;
2642 if (cache_stage != NULL) {
2643 tape->cache_stage = NULL;
2644 return cache_stage;
2645 }
2646 return __idetape_kmalloc_stage(tape, 0, 0);
2647 }
2648
2649 static void idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
2650 {
2651 struct idetape_bh *bh = tape->bh;
2652 int count;
2653
2654 while (n) {
2655 #if IDETAPE_DEBUG_BUGS
2656 if (bh == NULL) {
2657 printk(KERN_ERR "ide-tape: bh == NULL in "
2658 "idetape_copy_stage_from_user\n");
2659 return;
2660 }
2661 #endif /* IDETAPE_DEBUG_BUGS */
2662 count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
2663 copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count);
2664 n -= count;
2665 atomic_add(count, &bh->b_count);
2666 buf += count;
2667 if (atomic_read(&bh->b_count) == bh->b_size) {
2668 bh = bh->b_reqnext;
2669 if (bh)
2670 atomic_set(&bh->b_count, 0);
2671 }
2672 }
2673 tape->bh = bh;
2674 }
2675
2676 static void idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
2677 {
2678 struct idetape_bh *bh = tape->bh;
2679 int count;
2680
2681 while (n) {
2682 #if IDETAPE_DEBUG_BUGS
2683 if (bh == NULL) {
2684 printk(KERN_ERR "ide-tape: bh == NULL in "
2685 "idetape_copy_stage_to_user\n");
2686 return;
2687 }
2688 #endif /* IDETAPE_DEBUG_BUGS */
2689 count = min(tape->b_count, n);
2690 copy_to_user(buf, tape->b_data, count);
2691 n -= count;
2692 tape->b_data += count;
2693 tape->b_count -= count;
2694 buf += count;
2695 if (!tape->b_count) {
2696 tape->bh = bh = bh->b_reqnext;
2697 if (bh) {
2698 tape->b_data = bh->b_data;
2699 tape->b_count = atomic_read(&bh->b_count);
2700 }
2701 }
2702 }
2703 }
2704
2705 static void idetape_init_merge_stage (idetape_tape_t *tape)
2706 {
2707 struct idetape_bh *bh = tape->merge_stage->bh;
2708
2709 tape->bh = bh;
2710 if (tape->chrdev_direction == idetape_direction_write)
2711 atomic_set(&bh->b_count, 0);
2712 else {
2713 tape->b_data = bh->b_data;
2714 tape->b_count = atomic_read(&bh->b_count);
2715 }
2716 }
2717
2718 static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage)
2719 {
2720 struct idetape_bh *tmp;
2721
2722 tmp = stage->bh;
2723 stage->bh = tape->merge_stage->bh;
2724 tape->merge_stage->bh = tmp;
2725 idetape_init_merge_stage(tape);
2726 }
2727
2728 /*
2729 * idetape_add_stage_tail adds a new stage at the end of the pipeline.
2730 */
2731 static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage)
2732 {
2733 idetape_tape_t *tape = drive->driver_data;
2734 unsigned long flags;
2735
2736 #if IDETAPE_DEBUG_LOG
2737 if (tape->debug_level >= 4)
2738 printk (KERN_INFO "ide-tape: Reached idetape_add_stage_tail\n");
2739 #endif /* IDETAPE_DEBUG_LOG */
2740 spin_lock_irqsave(&tape->spinlock, flags);
2741 stage->next = NULL;
2742 if (tape->last_stage != NULL)
2743 tape->last_stage->next=stage;
2744 else
2745 tape->first_stage = tape->next_stage=stage;
2746 tape->last_stage = stage;
2747 if (tape->next_stage == NULL)
2748 tape->next_stage = tape->last_stage;
2749 tape->nr_stages++;
2750 tape->nr_pending_stages++;
2751 spin_unlock_irqrestore(&tape->spinlock, flags);
2752 }
2753
2754 /*
2755 * idetape_wait_for_request installs a completion in a pending request
2756 * and sleeps until it is serviced.
2757 *
2758 * The caller should ensure that the request will not be serviced
2759 * before we install the completion (usually by disabling interrupts).
2760 */
2761 static void idetape_wait_for_request (ide_drive_t *drive, struct request *rq)
2762 {
2763 DECLARE_COMPLETION(wait);
2764 idetape_tape_t *tape = drive->driver_data;
2765
2766 #if IDETAPE_DEBUG_BUGS
2767 if (rq == NULL || (rq->flags & REQ_SPECIAL) == 0) {
2768 printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n");
2769 return;
2770 }
2771 #endif /* IDETAPE_DEBUG_BUGS */
2772 rq->waiting = &wait;
2773 rq->end_io = blk_end_sync_rq;
2774 spin_unlock_irq(&tape->spinlock);
2775 wait_for_completion(&wait);
2776 /* The stage and its struct request have been deallocated */
2777 spin_lock_irq(&tape->spinlock);
2778 }
2779
2780 static ide_startstop_t idetape_read_position_callback (ide_drive_t *drive)
2781 {
2782 idetape_tape_t *tape = drive->driver_data;
2783 idetape_read_position_result_t *result;
2784
2785 #if IDETAPE_DEBUG_LOG
2786 if (tape->debug_level >= 4)
2787 printk(KERN_INFO "ide-tape: Reached idetape_read_position_callback\n");
2788 #endif /* IDETAPE_DEBUG_LOG */
2789
2790 if (!tape->pc->error) {
2791 result = (idetape_read_position_result_t *) tape->pc->buffer;
2792 #if IDETAPE_DEBUG_LOG
2793 if (tape->debug_level >= 2)
2794 printk(KERN_INFO "ide-tape: BOP - %s\n",result->bop ? "Yes":"No");
2795 if (tape->debug_level >= 2)
2796 printk(KERN_INFO "ide-tape: EOP - %s\n",result->eop ? "Yes":"No");
2797 #endif /* IDETAPE_DEBUG_LOG */
2798 if (result->bpu) {
2799 printk(KERN_INFO "ide-tape: Block location is unknown to the tape\n");
2800 clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
2801 idetape_end_request(drive, 0, 0);
2802 } else {
2803 #if IDETAPE_DEBUG_LOG
2804 if (tape->debug_level >= 2)
2805 printk(KERN_INFO "ide-tape: Block Location - %u\n", ntohl(result->first_block));
2806 #endif /* IDETAPE_DEBUG_LOG */
2807 tape->partition = result->partition;
2808 tape->first_frame_position = ntohl(result->first_block);
2809 tape->last_frame_position = ntohl(result->last_block);
2810 tape->blocks_in_buffer = result->blocks_in_buffer[2];
2811 set_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
2812 idetape_end_request(drive, 1, 0);
2813 }
2814 } else {
2815 idetape_end_request(drive, 0, 0);
2816 }
2817 return ide_stopped;
2818 }
2819
2820 /*
2821 * idetape_create_write_filemark_cmd will:
2822 *
2823 * 1. Write a filemark if write_filemark=1.
2824 * 2. Flush the device buffers without writing a filemark
2825 * if write_filemark=0.
2826 *
2827 */
2828 static void idetape_create_write_filemark_cmd (ide_drive_t *drive, idetape_pc_t *pc,int write_filemark)
2829 {
2830 idetape_init_pc(pc);
2831 pc->c[0] = IDETAPE_WRITE_FILEMARK_CMD;
2832 pc->c[4] = write_filemark;
2833 set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2834 pc->callback = &idetape_pc_callback;
2835 }
2836
2837 static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc)
2838 {
2839 idetape_init_pc(pc);
2840 pc->c[0] = IDETAPE_TEST_UNIT_READY_CMD;
2841 pc->callback = &idetape_pc_callback;
2842 }
2843
2844 /*
2845 * idetape_queue_pc_tail is based on the following functions:
2846 *
2847 * ide_do_drive_cmd from ide.c
2848 * cdrom_queue_request and cdrom_queue_packet_command from ide-cd.c
2849 *
2850 * We add a special packet command request to the tail of the request
2851 * queue, and wait for it to be serviced.
2852 *
2853 * This is not to be called from within the request handling part
2854 * of the driver ! We allocate here data in the stack, and it is valid
2855 * until the request is finished. This is not the case for the bottom
2856 * part of the driver, where we are always leaving the functions to wait
2857 * for an interrupt or a timer event.
2858 *
2859 * From the bottom part of the driver, we should allocate safe memory
2860 * using idetape_next_pc_storage and idetape_next_rq_storage, and add
2861 * the request to the request list without waiting for it to be serviced !
2862 * In that case, we usually use idetape_queue_pc_head.
2863 */
2864 static int __idetape_queue_pc_tail (ide_drive_t *drive, idetape_pc_t *pc)
2865 {
2866 struct ide_tape_obj *tape = drive->driver_data;
2867 struct request rq;
2868
2869 idetape_init_rq(&rq, REQ_IDETAPE_PC1);
2870 rq.buffer = (char *) pc;
2871 rq.rq_disk = tape->disk;
2872 return ide_do_drive_cmd(drive, &rq, ide_wait);
2873 }
2874
2875 static void idetape_create_load_unload_cmd (ide_drive_t *drive, idetape_pc_t *pc,int cmd)
2876 {
2877 idetape_init_pc(pc);
2878 pc->c[0] = IDETAPE_LOAD_UNLOAD_CMD;
2879 pc->c[4] = cmd;
2880 set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2881 pc->callback = &idetape_pc_callback;
2882 }
2883
2884 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
2885 {
2886 idetape_tape_t *tape = drive->driver_data;
2887 idetape_pc_t pc;
2888 int load_attempted = 0;
2889
2890 /*
2891 * Wait for the tape to become ready
2892 */
2893 set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
2894 timeout += jiffies;
2895 while (time_before(jiffies, timeout)) {
2896 idetape_create_test_unit_ready_cmd(&pc);
2897 if (!__idetape_queue_pc_tail(drive, &pc))
2898 return 0;
2899 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
2900 || (tape->asc == 0x3A)) { /* no media */
2901 if (load_attempted)
2902 return -ENOMEDIUM;
2903 idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
2904 __idetape_queue_pc_tail(drive, &pc);
2905 load_attempted = 1;
2906 /* not about to be ready */
2907 } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
2908 (tape->ascq == 1 || tape->ascq == 8)))
2909 return -EIO;
2910 msleep(100);
2911 }
2912 return -EIO;
2913 }
2914
2915 static int idetape_queue_pc_tail (ide_drive_t *drive,idetape_pc_t *pc)
2916 {
2917 return __idetape_queue_pc_tail(drive, pc);
2918 }
2919
2920 static int idetape_flush_tape_buffers (ide_drive_t *drive)
2921 {
2922 idetape_pc_t pc;
2923 int rc;
2924
2925 idetape_create_write_filemark_cmd(drive, &pc, 0);
2926 if ((rc = idetape_queue_pc_tail(drive, &pc)))
2927 return rc;
2928 idetape_wait_ready(drive, 60 * 5 * HZ);
2929 return 0;
2930 }
2931
2932 static void idetape_create_read_position_cmd (idetape_pc_t *pc)
2933 {
2934 idetape_init_pc(pc);
2935 pc->c[0] = IDETAPE_READ_POSITION_CMD;
2936 pc->request_transfer = 20;
2937 pc->callback = &idetape_read_position_callback;
2938 }
2939
2940 static int idetape_read_position (ide_drive_t *drive)
2941 {
2942 idetape_tape_t *tape = drive->driver_data;
2943 idetape_pc_t pc;
2944 int position;
2945
2946 #if IDETAPE_DEBUG_LOG
2947 if (tape->debug_level >= 4)
2948 printk(KERN_INFO "ide-tape: Reached idetape_read_position\n");
2949 #endif /* IDETAPE_DEBUG_LOG */
2950
2951 idetape_create_read_position_cmd(&pc);
2952 if (idetape_queue_pc_tail(drive, &pc))
2953 return -1;
2954 position = tape->first_frame_position;
2955 return position;
2956 }
2957
2958 static void idetape_create_locate_cmd (ide_drive_t *drive, idetape_pc_t *pc, unsigned int block, u8 partition, int skip)
2959 {
2960 idetape_init_pc(pc);
2961 pc->c[0] = IDETAPE_LOCATE_CMD;
2962 pc->c[1] = 2;
2963 put_unaligned(htonl(block), (unsigned int *) &pc->c[3]);
2964 pc->c[8] = partition;
2965 set_bit(PC_WAIT_FOR_DSC, &pc->flags);
2966 pc->callback = &idetape_pc_callback;
2967 }
2968
2969 static int idetape_create_prevent_cmd (ide_drive_t *drive, idetape_pc_t *pc, int prevent)
2970 {
2971 idetape_tape_t *tape = drive->driver_data;
2972
2973 if (!tape->capabilities.lock)
2974 return 0;
2975
2976 idetape_init_pc(pc);
2977 pc->c[0] = IDETAPE_PREVENT_CMD;
2978 pc->c[4] = prevent;
2979 pc->callback = &idetape_pc_callback;
2980 return 1;
2981 }
2982
2983 static int __idetape_discard_read_pipeline (ide_drive_t *drive)
2984 {
2985 idetape_tape_t *tape = drive->driver_data;
2986 unsigned long flags;
2987 int cnt;
2988
2989 if (tape->chrdev_direction != idetape_direction_read)
2990 return 0;
2991
2992 /* Remove merge stage. */
2993 cnt = tape->merge_stage_size / tape->tape_block_size;
2994 if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
2995 ++cnt; /* Filemarks count as 1 sector */
2996 tape->merge_stage_size = 0;
2997 if (tape->merge_stage != NULL) {
2998 __idetape_kfree_stage(tape->merge_stage);
2999 tape->merge_stage = NULL;
3000 }
3001
3002 /* Clear pipeline flags. */
3003 clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
3004 tape->chrdev_direction = idetape_direction_none;
3005
3006 /* Remove pipeline stages. */
3007 if (tape->first_stage == NULL)
3008 return 0;
3009
3010 spin_lock_irqsave(&tape->spinlock, flags);
3011 tape->next_stage = NULL;
3012 if (idetape_pipeline_active(tape))
3013 idetape_wait_for_request(drive, tape->active_data_request);
3014 spin_unlock_irqrestore(&tape->spinlock, flags);
3015
3016 while (tape->first_stage != NULL) {
3017 struct request *rq_ptr = &tape->first_stage->rq;
3018
3019 cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors;
3020 if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
3021 ++cnt;
3022 idetape_remove_stage_head(drive);
3023 }
3024 tape->nr_pending_stages = 0;
3025 tape->max_stages = tape->min_pipeline;
3026 return cnt;
3027 }
3028
3029 /*
3030 * idetape_position_tape positions the tape to the requested block
3031 * using the LOCATE packet command. A READ POSITION command is then
3032 * issued to check where we are positioned.
3033 *
3034 * Like all higher level operations, we queue the commands at the tail
3035 * of the request queue and wait for their completion.
3036 *
3037 */
3038 static int idetape_position_tape (ide_drive_t *drive, unsigned int block, u8 partition, int skip)
3039 {
3040 idetape_tape_t *tape = drive->driver_data;
3041 int retval;
3042 idetape_pc_t pc;
3043
3044 if (tape->chrdev_direction == idetape_direction_read)
3045 __idetape_discard_read_pipeline(drive);
3046 idetape_wait_ready(drive, 60 * 5 * HZ);
3047 idetape_create_locate_cmd(drive, &pc, block, partition, skip);
3048 retval = idetape_queue_pc_tail(drive, &pc);
3049 if (retval)
3050 return (retval);
3051
3052 idetape_create_read_position_cmd(&pc);
3053 return (idetape_queue_pc_tail(drive, &pc));
3054 }
3055
3056 static void idetape_discard_read_pipeline (ide_drive_t *drive, int restore_position)
3057 {
3058 idetape_tape_t *tape = drive->driver_data;
3059 int cnt;
3060 int seek, position;
3061
3062 cnt = __idetape_discard_read_pipeline(drive);
3063 if (restore_position) {
3064 position = idetape_read_position(drive);
3065 seek = position > cnt ? position - cnt : 0;
3066 if (idetape_position_tape(drive, seek, 0, 0)) {
3067 printk(KERN_INFO "ide-tape: %s: position_tape failed in discard_pipeline()\n", tape->name);
3068 return;
3069 }
3070 }
3071 }
3072
3073 /*
3074 * idetape_queue_rw_tail generates a read/write request for the block
3075 * device interface and wait for it to be serviced.
3076 */
3077 static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, struct idetape_bh *bh)
3078 {
3079 idetape_tape_t *tape = drive->driver_data;
3080 struct request rq;
3081
3082 #if IDETAPE_DEBUG_LOG
3083 if (tape->debug_level >= 2)
3084 printk(KERN_INFO "ide-tape: idetape_queue_rw_tail: cmd=%d\n",cmd);
3085 #endif /* IDETAPE_DEBUG_LOG */
3086 #if IDETAPE_DEBUG_BUGS
3087 if (idetape_pipeline_active(tape)) {
3088 printk(KERN_ERR "ide-tape: bug: the pipeline is active in idetape_queue_rw_tail\n");
3089 return (0);
3090 }
3091 #endif /* IDETAPE_DEBUG_BUGS */
3092
3093 idetape_init_rq(&rq, cmd);
3094 rq.rq_disk = tape->disk;
3095 rq.special = (void *)bh;
3096 rq.sector = tape->first_frame_position;
3097 rq.nr_sectors = rq.current_nr_sectors = blocks;
3098 (void) ide_do_drive_cmd(drive, &rq, ide_wait);
3099
3100 if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
3101 return 0;
3102
3103 if (tape->merge_stage)
3104 idetape_init_merge_stage(tape);
3105 if (rq.errors == IDETAPE_ERROR_GENERAL)
3106 return -EIO;
3107 return (tape->tape_block_size * (blocks-rq.current_nr_sectors));
3108 }
3109
3110 /*
3111 * idetape_insert_pipeline_into_queue is used to start servicing the
3112 * pipeline stages, starting from tape->next_stage.
3113 */
3114 static void idetape_insert_pipeline_into_queue (ide_drive_t *drive)
3115 {
3116 idetape_tape_t *tape = drive->driver_data;
3117
3118 if (tape->next_stage == NULL)
3119 return;
3120 if (!idetape_pipeline_active(tape)) {
3121 set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
3122 idetape_active_next_stage(drive);
3123 (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
3124 }
3125 }
3126
3127 static void idetape_create_inquiry_cmd (idetape_pc_t *pc)
3128 {
3129 idetape_init_pc(pc);
3130 pc->c[0] = IDETAPE_INQUIRY_CMD;
3131 pc->c[4] = pc->request_transfer = 254;
3132 pc->callback = &idetape_pc_callback;
3133 }
3134
3135 static void idetape_create_rewind_cmd (ide_drive_t *drive, idetape_pc_t *pc)
3136 {
3137 idetape_init_pc(pc);
3138 pc->c[0] = IDETAPE_REWIND_CMD;
3139 set_bit(PC_WAIT_FOR_DSC, &pc->flags);
3140 pc->callback = &idetape_pc_callback;
3141 }
3142
3143 #if 0
3144 static void idetape_create_mode_select_cmd (idetape_pc_t *pc, int length)
3145 {
3146 idetape_init_pc(pc);
3147 set_bit(PC_WRITING, &pc->flags);
3148 pc->c[0] = IDETAPE_MODE_SELECT_CMD;
3149 pc->c[1] = 0x10;
3150 put_unaligned(htons(length), (unsigned short *) &pc->c[3]);
3151 pc->request_transfer = 255;
3152 pc->callback = &idetape_pc_callback;
3153 }
3154 #endif
3155
3156 static void idetape_create_erase_cmd (idetape_pc_t *pc)
3157 {
3158 idetape_init_pc(pc);
3159 pc->c[0] = IDETAPE_ERASE_CMD;
3160 pc->c[1] = 1;
3161 set_bit(PC_WAIT_FOR_DSC, &pc->flags);
3162 pc->callback = &idetape_pc_callback;
3163 }
3164
3165 static void idetape_create_space_cmd (idetape_pc_t *pc,int count, u8 cmd)
3166 {
3167 idetape_init_pc(pc);
3168 pc->c[0] = IDETAPE_SPACE_CMD;
3169 put_unaligned(htonl(count), (unsigned int *) &pc->c[1]);
3170 pc->c[1] = cmd;
3171 set_bit(PC_WAIT_FOR_DSC, &pc->flags);
3172 pc->callback = &idetape_pc_callback;
3173 }
3174
3175 static void idetape_wait_first_stage (ide_drive_t *drive)
3176 {
3177 idetape_tape_t *tape = drive->driver_data;
3178 unsigned long flags;
3179
3180 if (tape->first_stage == NULL)
3181 return;
3182 spin_lock_irqsave(&tape->spinlock, flags);
3183 if (tape->active_stage == tape->first_stage)
3184 idetape_wait_for_request(drive, tape->active_data_request);
3185 spin_unlock_irqrestore(&tape->spinlock, flags);
3186 }
3187
3188 /*
3189 * idetape_add_chrdev_write_request tries to add a character device
3190 * originated write request to our pipeline. In case we don't succeed,
3191 * we revert to non-pipelined operation mode for this request.
3192 *
3193 * 1. Try to allocate a new pipeline stage.
3194 * 2. If we can't, wait for more and more requests to be serviced
3195 * and try again each time.
3196 * 3. If we still can't allocate a stage, fallback to
3197 * non-pipelined operation mode for this request.
3198 */
3199 static int idetape_add_chrdev_write_request (ide_drive_t *drive, int blocks)
3200 {
3201 idetape_tape_t *tape = drive->driver_data;
3202 idetape_stage_t *new_stage;
3203 unsigned long flags;
3204 struct request *rq;
3205
3206 #if IDETAPE_DEBUG_LOG
3207 if (tape->debug_level >= 3)
3208 printk(KERN_INFO "ide-tape: Reached idetape_add_chrdev_write_request\n");
3209 #endif /* IDETAPE_DEBUG_LOG */
3210
3211 /*
3212 * Attempt to allocate a new stage.
3213 * Pay special attention to possible race conditions.
3214 */
3215 while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) {
3216 spin_lock_irqsave(&tape->spinlock, flags);
3217 if (idetape_pipeline_active(tape)) {
3218 idetape_wait_for_request(drive, tape->active_data_request);
3219 spin_unlock_irqrestore(&tape->spinlock, flags);
3220 } else {
3221 spin_unlock_irqrestore(&tape->spinlock, flags);
3222 idetape_insert_pipeline_into_queue(drive);
3223 if (idetape_pipeline_active(tape))
3224 continue;
3225 /*
3226 * Linux is short on memory. Fallback to
3227 * non-pipelined operation mode for this request.
3228 */
3229 return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
3230 }
3231 }
3232 rq = &new_stage->rq;
3233 idetape_init_rq(rq, REQ_IDETAPE_WRITE);
3234 /* Doesn't actually matter - We always assume sequential access */
3235 rq->sector = tape->first_frame_position;
3236 rq->nr_sectors = rq->current_nr_sectors = blocks;
3237
3238 idetape_switch_buffers(tape, new_stage);
3239 idetape_add_stage_tail(drive, new_stage);
3240 tape->pipeline_head++;
3241 #if USE_IOTRACE
3242 IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
3243 #endif
3244 calculate_speeds(drive);
3245
3246 /*
3247 * Estimate whether the tape has stopped writing by checking
3248 * if our write pipeline is currently empty. If we are not
3249 * writing anymore, wait for the pipeline to be full enough
3250 * (90%) before starting to service requests, so that we will
3251 * be able to keep up with the higher speeds of the tape.
3252 */
3253 if (!idetape_pipeline_active(tape)) {
3254 if (tape->nr_stages >= tape->max_stages * 9 / 10 ||
3255 tape->nr_stages >= tape->max_stages - tape->uncontrolled_pipeline_head_speed * 3 * 1024 / tape->tape_block_size) {
3256 tape->measure_insert_time = 1;
3257 tape->insert_time = jiffies;
3258 tape->insert_size = 0;
3259 tape->insert_speed = 0;
3260 idetape_insert_pipeline_into_queue(drive);
3261 }
3262 }
3263 if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
3264 /* Return a deferred error */
3265 return -EIO;
3266 return blocks;
3267 }
3268
3269 /*
3270 * idetape_wait_for_pipeline will wait until all pending pipeline
3271 * requests are serviced. Typically called on device close.
3272 */
3273 static void idetape_wait_for_pipeline (ide_drive_t *drive)
3274 {
3275 idetape_tape_t *tape = drive->driver_data;
3276 unsigned long flags;
3277
3278 while (tape->next_stage || idetape_pipeline_active(tape)) {
3279 idetape_insert_pipeline_into_queue(drive);
3280 spin_lock_irqsave(&tape->spinlock, flags);
3281 if (idetape_pipeline_active(tape))
3282 idetape_wait_for_request(drive, tape->active_data_request);
3283 spin_unlock_irqrestore(&tape->spinlock, flags);
3284 }
3285 }
3286
3287 static void idetape_empty_write_pipeline (ide_drive_t *drive)
3288 {
3289 idetape_tape_t *tape = drive->driver_data;
3290 int blocks, min;
3291 struct idetape_bh *bh;
3292
3293 #if IDETAPE_DEBUG_BUGS
3294 if (tape->chrdev_direction != idetape_direction_write) {
3295 printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline, but we are not writing.\n");
3296 return;
3297 }
3298 if (tape->merge_stage_size > tape->stage_size) {
3299 printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
3300 tape->merge_stage_size = tape->stage_size;
3301 }
3302 #endif /* IDETAPE_DEBUG_BUGS */
3303 if (tape->merge_stage_size) {
3304 blocks = tape->merge_stage_size / tape->tape_block_size;
3305 if (tape->merge_stage_size % tape->tape_block_size) {
3306 unsigned int i;
3307
3308 blocks++;
3309