ide-tape.c 71.2 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1
/*
2 3
 * IDE ATAPI streaming tape driver.
 *
4 5
 * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
 * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
Linus Torvalds's avatar
Linus Torvalds committed
6 7 8 9 10 11 12 13
 *
 * This driver was constructed as a student project in the software laboratory
 * of the faculty of electrical engineering in the Technion - Israel's
 * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
 *
 * It is hereby placed under the terms of the GNU general public license.
 * (See linux/COPYING).
 *
14 15
 * For a historical changelog see
 * Documentation/ide/ChangeLog.ide-tape.1995-2002
Linus Torvalds's avatar
Linus Torvalds committed
16 17
 */

18 19
#define DRV_NAME "ide-tape"

20
#define IDETAPE_VERSION "1.20"
Linus Torvalds's avatar
Linus Torvalds committed
21 22 23 24 25 26 27 28 29

#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
30
#include <linux/jiffies.h>
Linus Torvalds's avatar
Linus Torvalds committed
31 32 33 34 35 36 37 38 39
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/ide.h>
#include <linux/smp_lock.h>
#include <linux/completion.h>
#include <linux/bitops.h>
40
#include <linux/mutex.h>
41
#include <scsi/scsi.h>
Linus Torvalds's avatar
Linus Torvalds committed
42 43

#include <asm/byteorder.h>
44 45 46
#include <linux/irq.h>
#include <linux/uaccess.h>
#include <linux/io.h>
Linus Torvalds's avatar
Linus Torvalds committed
47 48 49
#include <asm/unaligned.h>
#include <linux/mtio.h>

50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73
enum {
	/* output errors only */
	DBG_ERR =		(1 << 0),
	/* output all sense key/asc */
	DBG_SENSE =		(1 << 1),
	/* info regarding all chrdev-related procedures */
	DBG_CHRDEV =		(1 << 2),
	/* all remaining procedures */
	DBG_PROCS =		(1 << 3),
};

/* define to see debug info */
#define IDETAPE_DEBUG_LOG		0

#if IDETAPE_DEBUG_LOG
#define debug_log(lvl, fmt, args...)			\
{							\
	if (tape->debug_mask & lvl)			\
	printk(KERN_INFO "ide-tape: " fmt, ## args);	\
}
#else
#define debug_log(lvl, fmt, args...) do {} while (0)
#endif

Linus Torvalds's avatar
Linus Torvalds committed
74 75
/**************************** Tunable parameters *****************************/
/*
76 77
 * After each failed packet command we issue a request sense command and retry
 * the packet command IDETAPE_MAX_PC_RETRIES times.
Linus Torvalds's avatar
Linus Torvalds committed
78
 *
79
 * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
Linus Torvalds's avatar
Linus Torvalds committed
80 81 82 83
 */
#define IDETAPE_MAX_PC_RETRIES		3

/*
84 85
 * With each packet command, we allocate a buffer of IDETAPE_PC_BUFFER_SIZE
 * bytes. This is used for several packet commands (Not for READ/WRITE commands)
Linus Torvalds's avatar
Linus Torvalds committed
86 87 88 89 90 91 92 93 94 95 96
 */
#define IDETAPE_PC_BUFFER_SIZE		256

/*
 * Some drives (for example, Seagate STT3401A Travan) require a very long
 * timeout, because they don't return an interrupt or clear their busy bit
 * until after the command completes (even retension commands).
 */
#define IDETAPE_WAIT_CMD		(900*HZ)

/*
97 98 99 100
 * The following parameter is used to select the point in the internal tape fifo
 * in which we will start to refill the buffer. Decreasing the following
 * parameter will improve the system's latency and interactive response, while
 * using a high value might improve system throughput.
Linus Torvalds's avatar
Linus Torvalds committed
101
 */
102
#define IDETAPE_FIFO_THRESHOLD		2
Linus Torvalds's avatar
Linus Torvalds committed
103 104

/*
105
 * DSC polling parameters.
Linus Torvalds's avatar
Linus Torvalds committed
106
 *
107 108
 * Polling for DSC (a single bit in the status register) is a very important
 * function in ide-tape. There are two cases in which we poll for DSC:
Linus Torvalds's avatar
Linus Torvalds committed
109
 *
110 111 112 113 114
 * 1. Before a read/write packet command, to ensure that we can transfer data
 * from/to the tape's data buffers, without causing an actual media access.
 * In case the tape is not ready yet, we take out our request from the device
 * request queue, so that ide.c could service requests from the other device
 * on the same interface in the meantime.
Linus Torvalds's avatar
Linus Torvalds committed
115
 *
116 117 118 119 120 121 122 123
 * 2. After the successful initialization of a "media access packet command",
 * which is a command that can take a long time to complete (the interval can
 * range from several seconds to even an hour). Again, we postpone our request
 * in the middle to free the bus for the other device. The polling frequency
 * here should be lower than the read/write frequency since those media access
 * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
 * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
 * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
Linus Torvalds's avatar
Linus Torvalds committed
124
 *
125 126
 * We also set a timeout for the timer, in case something goes wrong. The
 * timeout should be longer then the maximum execution time of a tape operation.
Linus Torvalds's avatar
Linus Torvalds committed
127
 */
128 129

/* DSC timings. */
Linus Torvalds's avatar
Linus Torvalds committed
130 131 132 133 134 135 136 137 138 139
#define IDETAPE_DSC_RW_MIN		5*HZ/100	/* 50 msec */
#define IDETAPE_DSC_RW_MAX		40*HZ/100	/* 400 msec */
#define IDETAPE_DSC_RW_TIMEOUT		2*60*HZ		/* 2 minutes */
#define IDETAPE_DSC_MA_FAST		2*HZ		/* 2 seconds */
#define IDETAPE_DSC_MA_THRESHOLD	5*60*HZ		/* 5 minutes */
#define IDETAPE_DSC_MA_SLOW		30*HZ		/* 30 seconds */
#define IDETAPE_DSC_MA_TIMEOUT		2*60*60*HZ	/* 2 hours */

/*************************** End of tunable parameters ***********************/

140 141 142 143 144 145
/* tape directions */
enum {
	IDETAPE_DIR_NONE  = (1 << 0),
	IDETAPE_DIR_READ  = (1 << 1),
	IDETAPE_DIR_WRITE = (1 << 2),
};
Linus Torvalds's avatar
Linus Torvalds committed
146 147

struct idetape_bh {
148
	u32 b_size;
Linus Torvalds's avatar
Linus Torvalds committed
149 150 151 152 153
	atomic_t b_count;
	struct idetape_bh *b_reqnext;
	char *b_data;
};

154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190
/* Tape door status */
#define DOOR_UNLOCKED			0
#define DOOR_LOCKED			1
#define DOOR_EXPLICITLY_LOCKED		2

/* Some defines for the SPACE command */
#define IDETAPE_SPACE_OVER_FILEMARK	1
#define IDETAPE_SPACE_TO_EOD		3

/* Some defines for the LOAD UNLOAD command */
#define IDETAPE_LU_LOAD_MASK		1
#define IDETAPE_LU_RETENSION_MASK	2
#define IDETAPE_LU_EOT_MASK		4

/*
 * Special requests for our block device strategy routine.
 *
 * In order to service a character device command, we add special requests to
 * the tail of our block device request queue and wait for their completion.
 */

enum {
	REQ_IDETAPE_PC1		= (1 << 0), /* packet command (first stage) */
	REQ_IDETAPE_PC2		= (1 << 1), /* packet command (second stage) */
	REQ_IDETAPE_READ	= (1 << 2),
	REQ_IDETAPE_WRITE	= (1 << 3),
};

/* Error codes returned in rq->errors to the higher part of the driver. */
#define IDETAPE_ERROR_GENERAL		101
#define IDETAPE_ERROR_FILEMARK		102
#define IDETAPE_ERROR_EOD		103

/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
#define IDETAPE_BLOCK_DESCRIPTOR	0
#define IDETAPE_CAPABILITIES_PAGE	0x2a

Linus Torvalds's avatar
Linus Torvalds committed
191
/*
192 193
 * Most of our global data which we need to save even as we leave the driver due
 * to an interrupt or a timer event is stored in the struct defined below.
Linus Torvalds's avatar
Linus Torvalds committed
194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209
 */
typedef struct ide_tape_obj {
	ide_drive_t	*drive;
	ide_driver_t	*driver;
	struct gendisk	*disk;
	struct kref	kref;

	/*
	 *	pc points to the current processed packet command.
	 *
	 *	failed_pc points to the last failed packet command, or contains
	 *	NULL if we do not need to retry any packet command. This is
	 *	required since an additional packet command is needed before the
	 *	retry, to get detailed information on what went wrong.
	 */
	/* Current packet command */
210
	struct ide_atapi_pc *pc;
Linus Torvalds's avatar
Linus Torvalds committed
211
	/* Last failed packet command */
212
	struct ide_atapi_pc *failed_pc;
213 214
	/* used by REQ_IDETAPE_{READ,WRITE} requests */
	struct ide_atapi_pc queued_pc;
215

216
	struct ide_atapi_pc request_sense_pc;
217
	struct request request_sense_rq;
Linus Torvalds's avatar
Linus Torvalds committed
218 219

	/*
220
	 * DSC polling variables.
Linus Torvalds's avatar
Linus Torvalds committed
221
	 *
222 223 224
	 * While polling for DSC we use postponed_rq to postpone the current
	 * request so that ide.c will be able to service pending requests on the
	 * other device. Note that at most we will have only one DSC (usually
225
	 * data transfer) request in the device request queue.
Linus Torvalds's avatar
Linus Torvalds committed
226 227 228 229 230 231 232
	 */
	struct request *postponed_rq;
	/* The time in which we started polling for DSC */
	unsigned long dsc_polling_start;
	/* Timer used to poll for dsc */
	struct timer_list dsc_timer;
	/* Read/Write dsc polling frequency */
233 234
	unsigned long best_dsc_rw_freq;
	unsigned long dsc_poll_freq;
Linus Torvalds's avatar
Linus Torvalds committed
235 236
	unsigned long dsc_timeout;

237
	/* Read position information */
Linus Torvalds's avatar
Linus Torvalds committed
238 239
	u8 partition;
	/* Current block */
240
	unsigned int first_frame;
Linus Torvalds's avatar
Linus Torvalds committed
241

242
	/* Last error information */
Linus Torvalds's avatar
Linus Torvalds committed
243 244
	u8 sense_key, asc, ascq;

245
	/* Character device operation */
Linus Torvalds's avatar
Linus Torvalds committed
246 247 248 249
	unsigned int minor;
	/* device name */
	char name[4];
	/* Current character device data transfer direction */
250
	u8 chrdev_dir;
Linus Torvalds's avatar
Linus Torvalds committed
251

252 253
	/* tape block size, usually 512 or 1024 bytes */
	unsigned short blk_size;
Linus Torvalds's avatar
Linus Torvalds committed
254
	int user_bs_factor;
255

Linus Torvalds's avatar
Linus Torvalds committed
256
	/* Copy of the tape's Capabilities and Mechanical Page */
257
	u8 caps[20];
Linus Torvalds's avatar
Linus Torvalds committed
258 259

	/*
260
	 * Active data transfer request parameters.
Linus Torvalds's avatar
Linus Torvalds committed
261
	 *
262 263 264
	 * At most, there is only one ide-tape originated data transfer request
	 * in the device request queue. This allows ide.c to easily service
	 * requests from the other device when we postpone our active request.
Linus Torvalds's avatar
Linus Torvalds committed
265
	 */
266

267
	/* Data buffer size chosen based on the tape's recommendation */
268
	int buffer_size;
269 270
	/* merge buffer */
	struct idetape_bh *merge_bh;
271 272
	/* size of the merge buffer */
	int merge_bh_size;
273
	/* pointer to current buffer head within the merge buffer */
Linus Torvalds's avatar
Linus Torvalds committed
274 275 276
	struct idetape_bh *bh;
	char *b_data;
	int b_count;
277

278
	int pages_per_buffer;
Linus Torvalds's avatar
Linus Torvalds committed
279 280 281 282
	/* Wasted space in each stage */
	int excess_bh_size;

	/* protects the ide-tape queue */
283
	spinlock_t lock;
Linus Torvalds's avatar
Linus Torvalds committed
284

285
	/* Measures average tape speed */
Linus Torvalds's avatar
Linus Torvalds committed
286 287 288 289 290 291 292 293 294 295 296
	unsigned long avg_time;
	int avg_size;
	int avg_speed;

	/* the door is currently locked */
	int door_locked;
	/* the tape hardware is write protected */
	char drv_write_prot;
	/* the tape is write protected (hardware or opened as read-only) */
	char write_prot;

297
	u32 debug_mask;
Linus Torvalds's avatar
Linus Torvalds committed
298 299
} idetape_tape_t;

300
static DEFINE_MUTEX(idetape_ref_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
301

302 303
static struct class *idetape_sysfs_class;

Linus Torvalds's avatar
Linus Torvalds committed
304 305 306 307 308
#define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref)

#define ide_tape_g(disk) \
	container_of((disk)->private_data, struct ide_tape_obj, driver)

309 310
static void ide_tape_release(struct kref *);

Linus Torvalds's avatar
Linus Torvalds committed
311 312 313 314
static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
{
	struct ide_tape_obj *tape = NULL;

315
	mutex_lock(&idetape_ref_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
316
	tape = ide_tape_g(disk);
317
	if (tape) {
318
		if (ide_device_get(tape->drive))
319
			tape = NULL;
320 321
		else
			kref_get(&tape->kref);
322
	}
323
	mutex_unlock(&idetape_ref_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
324 325 326 327 328
	return tape;
}

static void ide_tape_put(struct ide_tape_obj *tape)
{
329 330
	ide_drive_t *drive = tape->drive;

331
	mutex_lock(&idetape_ref_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
332
	kref_put(&tape->kref, ide_tape_release);
333
	ide_device_put(drive);
334
	mutex_unlock(&idetape_ref_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
335 336 337
}

/*
338 339
 * The variables below are used for the character device interface. Additional
 * state variables are defined in our ide_drive_t structure.
Linus Torvalds's avatar
Linus Torvalds committed
340
 */
341
static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
Linus Torvalds's avatar
Linus Torvalds committed
342 343 344 345 346 347 348

#define ide_tape_f(file) ((file)->private_data)

static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
{
	struct ide_tape_obj *tape = NULL;

349
	mutex_lock(&idetape_ref_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
350 351 352
	tape = idetape_devs[i];
	if (tape)
		kref_get(&tape->kref);
353
	mutex_unlock(&idetape_ref_mutex);
Linus Torvalds's avatar
Linus Torvalds committed
354 355 356
	return tape;
}

357
static void idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
358
				  unsigned int bcount)
Linus Torvalds's avatar
Linus Torvalds committed
359 360 361 362 363 364 365 366
{
	struct idetape_bh *bh = pc->bh;
	int count;

	while (bcount) {
		if (bh == NULL) {
			printk(KERN_ERR "ide-tape: bh == NULL in "
				"idetape_input_buffers\n");
367
			ide_pad_transfer(drive, 0, bcount);
Linus Torvalds's avatar
Linus Torvalds committed
368 369
			return;
		}
370 371 372
		count = min(
			(unsigned int)(bh->b_size - atomic_read(&bh->b_count)),
			bcount);
373
		drive->hwif->tp_ops->input_data(drive, NULL, bh->b_data +
374
					atomic_read(&bh->b_count), count);
Linus Torvalds's avatar
Linus Torvalds committed
375 376 377 378 379 380 381 382 383 384 385
		bcount -= count;
		atomic_add(count, &bh->b_count);
		if (atomic_read(&bh->b_count) == bh->b_size) {
			bh = bh->b_reqnext;
			if (bh)
				atomic_set(&bh->b_count, 0);
		}
	}
	pc->bh = bh;
}

386
static void idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
387
				   unsigned int bcount)
Linus Torvalds's avatar
Linus Torvalds committed
388 389 390 391 392 393
{
	struct idetape_bh *bh = pc->bh;
	int count;

	while (bcount) {
		if (bh == NULL) {
394 395
			printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
					__func__);
Linus Torvalds's avatar
Linus Torvalds committed
396 397 398
			return;
		}
		count = min((unsigned int)pc->b_count, (unsigned int)bcount);
399
		drive->hwif->tp_ops->output_data(drive, NULL, pc->b_data, count);
Linus Torvalds's avatar
Linus Torvalds committed
400 401 402 403
		bcount -= count;
		pc->b_data += count;
		pc->b_count -= count;
		if (!pc->b_count) {
404 405
			bh = bh->b_reqnext;
			pc->bh = bh;
Linus Torvalds's avatar
Linus Torvalds committed
406 407 408 409 410 411 412 413
			if (bh) {
				pc->b_data = bh->b_data;
				pc->b_count = atomic_read(&bh->b_count);
			}
		}
	}
}

414
static void idetape_update_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc)
Linus Torvalds's avatar
Linus Torvalds committed
415 416 417
{
	struct idetape_bh *bh = pc->bh;
	int count;
418
	unsigned int bcount = pc->xferred;
Linus Torvalds's avatar
Linus Torvalds committed
419

420
	if (pc->flags & PC_FLAG_WRITING)
Linus Torvalds's avatar
Linus Torvalds committed
421 422 423
		return;
	while (bcount) {
		if (bh == NULL) {
424 425
			printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
					__func__);
Linus Torvalds's avatar
Linus Torvalds committed
426 427 428 429 430 431 432 433 434 435 436 437
			return;
		}
		count = min((unsigned int)bh->b_size, (unsigned int)bcount);
		atomic_set(&bh->b_count, count);
		if (atomic_read(&bh->b_count) == bh->b_size)
			bh = bh->b_reqnext;
		bcount -= count;
	}
	pc->bh = bh;
}

/*
438 439
 * called on each failed packet command retry to analyze the request sense. We
 * currently do not utilize this information.
Linus Torvalds's avatar
Linus Torvalds committed
440
 */
441
static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
Linus Torvalds's avatar
Linus Torvalds committed
442 443
{
	idetape_tape_t *tape = drive->driver_data;
444
	struct ide_atapi_pc *pc = tape->failed_pc;
Linus Torvalds's avatar
Linus Torvalds committed
445

446 447 448
	tape->sense_key = sense[2] & 0xF;
	tape->asc       = sense[12];
	tape->ascq      = sense[13];
449 450 451

	debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
		 pc->c[0], tape->sense_key, tape->asc, tape->ascq);
Linus Torvalds's avatar
Linus Torvalds committed
452

453
	/* Correct pc->xferred by asking the tape.	 */
454
	if (pc->flags & PC_FLAG_DMA_ERROR) {
455
		pc->xferred = pc->req_xfer -
456
			tape->blk_size *
457
			get_unaligned_be32(&sense[3]);
458
		idetape_update_buffers(drive, pc);
Linus Torvalds's avatar
Linus Torvalds committed
459 460 461 462 463 464 465
	}

	/*
	 * If error was the result of a zero-length read or write command,
	 * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
	 * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
	 */
466
	if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
467 468 469
	    /* length == 0 */
	    && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
		if (tape->sense_key == 5) {
Linus Torvalds's avatar
Linus Torvalds committed
470 471 472
			/* don't report an error, everything's ok */
			pc->error = 0;
			/* don't retry read/write */
473
			pc->flags |= PC_FLAG_ABORT;
Linus Torvalds's avatar
Linus Torvalds committed
474 475
		}
	}
476
	if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
Linus Torvalds's avatar
Linus Torvalds committed
477
		pc->error = IDETAPE_ERROR_FILEMARK;
478
		pc->flags |= PC_FLAG_ABORT;
Linus Torvalds's avatar
Linus Torvalds committed
479
	}
480
	if (pc->c[0] == WRITE_6) {
481 482
		if ((sense[2] & 0x40) || (tape->sense_key == 0xd
		     && tape->asc == 0x0 && tape->ascq == 0x2)) {
Linus Torvalds's avatar
Linus Torvalds committed
483
			pc->error = IDETAPE_ERROR_EOD;
484
			pc->flags |= PC_FLAG_ABORT;
Linus Torvalds's avatar
Linus Torvalds committed
485 486
		}
	}
487
	if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
488
		if (tape->sense_key == 8) {
Linus Torvalds's avatar
Linus Torvalds committed
489
			pc->error = IDETAPE_ERROR_EOD;
490
			pc->flags |= PC_FLAG_ABORT;
Linus Torvalds's avatar
Linus Torvalds committed
491
		}
492
		if (!(pc->flags & PC_FLAG_ABORT) &&
493
		    pc->xferred)
Linus Torvalds's avatar
Linus Torvalds committed
494 495 496 497
			pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
	}
}

498
/* Free data buffers completely. */
499
static void ide_tape_kfree_buffer(idetape_tape_t *tape)
Linus Torvalds's avatar
Linus Torvalds committed
500
{
501
	struct idetape_bh *prev_bh, *bh = tape->merge_bh;
502 503 504 505 506 507 508 509 510 511 512 513

	while (bh) {
		u32 size = bh->b_size;

		while (size) {
			unsigned int order = fls(size >> PAGE_SHIFT)-1;

			if (bh->b_data)
				free_pages((unsigned long)bh->b_data, order);

			size &= (order-1);
			bh->b_data += (1 << order) * PAGE_SIZE;
Linus Torvalds's avatar
Linus Torvalds committed
514 515 516 517 518 519 520 521 522 523 524 525 526 527
		}
		prev_bh = bh;
		bh = bh->b_reqnext;
		kfree(prev_bh);
	}
}

static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
{
	struct request *rq = HWGROUP(drive)->rq;
	idetape_tape_t *tape = drive->driver_data;
	unsigned long flags;
	int error;

528
	debug_log(DBG_PROCS, "Enter %s\n", __func__);
Linus Torvalds's avatar
Linus Torvalds committed
529 530

	switch (uptodate) {
531 532 533
	case 0:	error = IDETAPE_ERROR_GENERAL; break;
	case 1: error = 0; break;
	default: error = uptodate;
Linus Torvalds's avatar
Linus Torvalds committed
534 535 536 537 538
	}
	rq->errors = error;
	if (error)
		tape->failed_pc = NULL;

539 540 541 542 543
	if (!blk_special_request(rq)) {
		ide_end_request(drive, uptodate, nr_sects);
		return 0;
	}

544
	spin_lock_irqsave(&tape->lock, flags);
Linus Torvalds's avatar
Linus Torvalds committed
545 546 547

	ide_end_drive_cmd(drive, 0, 0);

548
	spin_unlock_irqrestore(&tape->lock, flags);
Linus Torvalds's avatar
Linus Torvalds committed
549 550 551
	return 0;
}

552
static void ide_tape_callback(ide_drive_t *drive)
Linus Torvalds's avatar
Linus Torvalds committed
553 554
{
	idetape_tape_t *tape = drive->driver_data;
555 556
	struct ide_atapi_pc *pc = tape->pc;
	int uptodate = pc->error ? 0 : 1;
Linus Torvalds's avatar
Linus Torvalds committed
557

558 559
	debug_log(DBG_PROCS, "Enter %s\n", __func__);

560 561 562
	if (tape->failed_pc == pc)
		tape->failed_pc = NULL;

563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597
	if (pc->c[0] == REQUEST_SENSE) {
		if (uptodate)
			idetape_analyze_error(drive, pc->buf);
		else
			printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
					"itself - Aborting request!\n");
	} else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
		struct request *rq = drive->hwif->hwgroup->rq;
		int blocks = pc->xferred / tape->blk_size;

		tape->avg_size += blocks * tape->blk_size;

		if (time_after_eq(jiffies, tape->avg_time + HZ)) {
			tape->avg_speed = tape->avg_size * HZ /
				(jiffies - tape->avg_time) / 1024;
			tape->avg_size = 0;
			tape->avg_time = jiffies;
		}

		tape->first_frame += blocks;
		rq->current_nr_sectors -= blocks;

		if (pc->error)
			uptodate = pc->error;
	} else if (pc->c[0] == READ_POSITION && uptodate) {
		u8 *readpos = tape->pc->buf;

		debug_log(DBG_SENSE, "BOP - %s\n",
				(readpos[0] & 0x80) ? "Yes" : "No");
		debug_log(DBG_SENSE, "EOP - %s\n",
				(readpos[0] & 0x40) ? "Yes" : "No");

		if (readpos[0] & 0x4) {
			printk(KERN_INFO "ide-tape: Block location is unknown"
					 "to the tape\n");
598
			clear_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
599 600 601
			uptodate = 0;
		} else {
			debug_log(DBG_SENSE, "Block Location - %u\n",
602
					be32_to_cpup((__be32 *)&readpos[4]));
603 604

			tape->partition = readpos[1];
605
			tape->first_frame = be32_to_cpup((__be32 *)&readpos[4]);
606
			set_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
607
		}
Linus Torvalds's avatar
Linus Torvalds committed
608
	}
609 610

	idetape_end_request(drive, uptodate, 0);
Linus Torvalds's avatar
Linus Torvalds committed
611 612
}

613 614 615 616 617 618 619 620 621 622
static void idetape_init_pc(struct ide_atapi_pc *pc)
{
	memset(pc->c, 0, 12);
	pc->retries = 0;
	pc->flags = 0;
	pc->req_xfer = 0;
	pc->buf = pc->pc_buf;
	pc->buf_size = IDETAPE_PC_BUFFER_SIZE;
	pc->bh = NULL;
	pc->b_data = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
623 624
}

625
static void idetape_create_request_sense_cmd(struct ide_atapi_pc *pc)
Linus Torvalds's avatar
Linus Torvalds committed
626
{
627
	idetape_init_pc(pc);
628
	pc->c[0] = REQUEST_SENSE;
Linus Torvalds's avatar
Linus Torvalds committed
629
	pc->c[4] = 20;
630
	pc->req_xfer = 20;
Linus Torvalds's avatar
Linus Torvalds committed
631 632 633
}

/*
634 635
 * Generate a new packet command request in front of the request queue, before
 * the current request, so that it will be processed immediately, on the next
636
 * pass through the driver.
Linus Torvalds's avatar
Linus Torvalds committed
637
 */
638
static void idetape_queue_pc_head(ide_drive_t *drive, struct ide_atapi_pc *pc,
639
				  struct request *rq)
Linus Torvalds's avatar
Linus Torvalds committed
640 641 642
{
	struct ide_tape_obj *tape = drive->driver_data;

643 644
	blk_rq_init(NULL, rq);
	rq->cmd_type = REQ_TYPE_SPECIAL;
645
	rq->cmd_flags |= REQ_PREEMPT;
Linus Torvalds's avatar
Linus Torvalds committed
646 647
	rq->buffer = (char *) pc;
	rq->rq_disk = tape->disk;
648
	memcpy(rq->cmd, pc->c, 12);
649
	rq->cmd[13] = REQ_IDETAPE_PC1;
650
	ide_do_drive_cmd(drive, rq);
Linus Torvalds's avatar
Linus Torvalds committed
651 652 653 654 655 656 657
}

/*
 *	idetape_retry_pc is called when an error was detected during the
 *	last packet command. We queue a request sense packet command in
 *	the head of the request list.
 */
658
static void idetape_retry_pc(ide_drive_t *drive)
Linus Torvalds's avatar
Linus Torvalds committed
659
{
660 661
	struct ide_tape_obj *tape = drive->driver_data;
	struct request *rq = &tape->request_sense_rq;
662
	struct ide_atapi_pc *pc = &tape->request_sense_pc;
Linus Torvalds's avatar
Linus Torvalds committed
663

664
	(void)ide_read_error(drive);
Linus Torvalds's avatar
Linus Torvalds committed
665
	idetape_create_request_sense_cmd(pc);
666
	set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
Linus Torvalds's avatar
Linus Torvalds committed
667 668 669 670
	idetape_queue_pc_head(drive, pc, rq);
}

/*
671 672
 * Postpone the current request so that ide.c will be able to service requests
 * from another device on the same hwgroup while we are polling for DSC.
Linus Torvalds's avatar
Linus Torvalds committed
673
 */
674
static void idetape_postpone_request(ide_drive_t *drive)
Linus Torvalds's avatar
Linus Torvalds committed
675 676 677
{
	idetape_tape_t *tape = drive->driver_data;

678 679
	debug_log(DBG_PROCS, "Enter %s\n", __func__);

Linus Torvalds's avatar
Linus Torvalds committed
680
	tape->postponed_rq = HWGROUP(drive)->rq;
681
	ide_stall_queue(drive, tape->dsc_poll_freq);
Linus Torvalds's avatar
Linus Torvalds committed
682 683
}

684 685 686 687 688 689 690 691 692 693 694 695
static void ide_tape_handle_dsc(ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;

	/* Media access command */
	tape->dsc_polling_start = jiffies;
	tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
	tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
	/* Allow ide.c to handle other requests */
	idetape_postpone_request(drive);
}

696 697 698 699 700 701 702 703
static void ide_tape_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
				unsigned int bcount, int write)
{
	if (write)
		idetape_output_buffers(drive, pc, bcount);
	else
		idetape_input_buffers(drive, pc, bcount);
}
704

Linus Torvalds's avatar
Linus Torvalds committed
705
/*
706 707 708 709
 * This is the usual interrupt handler which will be called during a packet
 * command. We will transfer some of the data (as requested by the drive) and
 * will re-point interrupt handler to us. When data transfer is finished, we
 * will act according to the algorithm described before
710
 * idetape_issue_pc.
Linus Torvalds's avatar
Linus Torvalds committed
711
 */
712
static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
Linus Torvalds's avatar
Linus Torvalds committed
713 714 715
{
	idetape_tape_t *tape = drive->driver_data;

716 717 718
	return ide_pc_intr(drive, tape->pc, idetape_pc_intr, IDETAPE_WAIT_CMD,
			   NULL, idetape_update_buffers, idetape_retry_pc,
			   ide_tape_handle_dsc, ide_tape_io_buffers);
Linus Torvalds's avatar
Linus Torvalds committed
719 720 721
}

/*
722
 * Packet Command Interface
Linus Torvalds's avatar
Linus Torvalds committed
723
 *
724 725 726
 * The current Packet Command is available in tape->pc, and will not change
 * until we finish handling it. Each packet command is associated with a
 * callback function that will be called when the command is finished.
Linus Torvalds's avatar
Linus Torvalds committed
727
 *
728
 * The handling will be done in three stages:
Linus Torvalds's avatar
Linus Torvalds committed
729
 *
730 731
 * 1. idetape_issue_pc will send the packet command to the drive, and will set
 * the interrupt handler to idetape_pc_intr.
Linus Torvalds's avatar
Linus Torvalds committed
732
 *
733 734
 * 2. On each interrupt, idetape_pc_intr will be called. This step will be
 * repeated until the device signals us that no more interrupts will be issued.
Linus Torvalds's avatar
Linus Torvalds committed
735
 *
736 737 738 739 740 741 742
 * 3. ATAPI Tape media access commands have immediate status with a delayed
 * process. In case of a successful initiation of a media access packet command,
 * the DSC bit will be set when the actual execution of the command is finished.
 * Since the tape drive will not issue an interrupt, we have to poll for this
 * event. In this case, we define the request as "low priority request" by
 * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 * exit the driver.
Linus Torvalds's avatar
Linus Torvalds committed
743
 *
744 745
 * ide.c will then give higher priority to requests which originate from the
 * other device, until will change rq_status to RQ_ACTIVE.
Linus Torvalds's avatar
Linus Torvalds committed
746
 *
747
 * 4. When the packet command is finished, it will be checked for errors.
Linus Torvalds's avatar
Linus Torvalds committed
748
 *
749 750 751
 * 5. In case an error was found, we queue a request sense packet command in
 * front of the request queue and retry the operation up to
 * IDETAPE_MAX_PC_RETRIES times.
Linus Torvalds's avatar
Linus Torvalds committed
752
 *
753 754 755
 * 6. In case no error was found, or we decided to give up and not to retry
 * again, the callback function will be called and then we will handle the next
 * request.
Linus Torvalds's avatar
Linus Torvalds committed
756 757 758 759
 */
static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
760

761 762
	return ide_transfer_pc(drive, tape->pc, idetape_pc_intr,
			       IDETAPE_WAIT_CMD, NULL);
Linus Torvalds's avatar
Linus Torvalds committed
763 764
}

765 766
static ide_startstop_t idetape_issue_pc(ide_drive_t *drive,
		struct ide_atapi_pc *pc)
Linus Torvalds's avatar
Linus Torvalds committed
767 768 769
{
	idetape_tape_t *tape = drive->driver_data;

770 771
	if (tape->pc->c[0] == REQUEST_SENSE &&
	    pc->c[0] == REQUEST_SENSE) {
Linus Torvalds's avatar
Linus Torvalds committed
772 773 774 775
		printk(KERN_ERR "ide-tape: possible ide-tape.c bug - "
			"Two request sense in serial were issued\n");
	}

776
	if (tape->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
Linus Torvalds's avatar
Linus Torvalds committed
777 778 779 780 781
		tape->failed_pc = pc;
	/* Set the current packet command */
	tape->pc = pc;

	if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
782
		(pc->flags & PC_FLAG_ABORT)) {
Linus Torvalds's avatar
Linus Torvalds committed
783
		/*
784 785 786
		 * We will "abort" retrying a packet command in case legitimate
		 * error code was received (crossing a filemark, or end of the
		 * media, for example).
Linus Torvalds's avatar
Linus Torvalds committed
787
		 */
788
		if (!(pc->flags & PC_FLAG_ABORT)) {
789
			if (!(pc->c[0] == TEST_UNIT_READY &&
Linus Torvalds's avatar
Linus Torvalds committed
790 791 792 793 794 795 796 797 798 799 800 801 802
			      tape->sense_key == 2 && tape->asc == 4 &&
			     (tape->ascq == 1 || tape->ascq == 8))) {
				printk(KERN_ERR "ide-tape: %s: I/O error, "
						"pc = %2x, key = %2x, "
						"asc = %2x, ascq = %2x\n",
						tape->name, pc->c[0],
						tape->sense_key, tape->asc,
						tape->ascq);
			}
			/* Giving up */
			pc->error = IDETAPE_ERROR_GENERAL;
		}
		tape->failed_pc = NULL;
803
		drive->pc_callback(drive);
804
		return ide_stopped;
Linus Torvalds's avatar
Linus Torvalds committed
805
	}
806
	debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
Linus Torvalds's avatar
Linus Torvalds committed
807 808 809

	pc->retries++;

810 811
	return ide_issue_pc(drive, pc, idetape_transfer_pc,
			    IDETAPE_WAIT_CMD, NULL);
Linus Torvalds's avatar
Linus Torvalds committed
812 813
}

814
/* A mode sense command is used to "sense" tape parameters. */
815
static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
Linus Torvalds's avatar
Linus Torvalds committed
816 817
{
	idetape_init_pc(pc);
818
	pc->c[0] = MODE_SENSE;
Linus Torvalds's avatar
Linus Torvalds committed
819
	if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
820 821
		/* DBD = 1 - Don't return block descriptors */
		pc->c[1] = 8;
Linus Torvalds's avatar
Linus Torvalds committed
822 823 824 825 826 827 828 829 830
	pc->c[2] = page_code;
	/*
	 * Changed pc->c[3] to 0 (255 will at best return unused info).
	 *
	 * For SCSI this byte is defined as subpage instead of high byte
	 * of length and some IDE drives seem to interpret it this way
	 * and return an error when 255 is used.
	 */
	pc->c[3] = 0;
831 832
	/* We will just discard data in that case */
	pc->c[4] = 255;
Linus Torvalds's avatar
Linus Torvalds committed
833
	if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
834
		pc->req_xfer = 12;
Linus Torvalds's avatar
Linus Torvalds committed
835
	else if (page_code == IDETAPE_CAPABILITIES_PAGE)
836
		pc->req_xfer = 24;
Linus Torvalds's avatar
Linus Torvalds committed
837
	else
838
		pc->req_xfer = 50;
Linus Torvalds's avatar
Linus Torvalds committed
839 840
}

841
static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
Linus Torvalds's avatar
Linus Torvalds committed
842
{
843
	ide_hwif_t *hwif = drive->hwif;
Linus Torvalds's avatar
Linus Torvalds committed
844
	idetape_tape_t *tape = drive->driver_data;
845
	struct ide_atapi_pc *pc = tape->pc;
846
	u8 stat;
Linus Torvalds's avatar
Linus Torvalds committed
847

848
	stat = hwif->tp_ops->read_status(hwif);
849

850 851
	if (stat & ATA_DSC) {
		if (stat & ATA_ERR) {
Linus Torvalds's avatar
Linus Torvalds committed
852
			/* Error detected */
853
			if (pc->c[0] != TEST_UNIT_READY)
Linus Torvalds's avatar
Linus Torvalds committed
854 855 856
				printk(KERN_ERR "ide-tape: %s: I/O error, ",
						tape->name);
			/* Retry operation */
857 858
			idetape_retry_pc(drive);
			return ide_stopped;
Linus Torvalds's avatar
Linus Torvalds committed
859 860 861 862 863 864
		}
		pc->error = 0;
	} else {
		pc->error = IDETAPE_ERROR_GENERAL;
		tape->failed_pc = NULL;
	}
865
	drive->pc_callback(drive);
Linus Torvalds's avatar
Linus Torvalds committed
866 867 868
	return ide_stopped;
}

869
static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
870 871
				   struct ide_atapi_pc *pc, struct request *rq,
				   u8 opcode)
Linus Torvalds's avatar
Linus Torvalds committed
872
{
873 874 875
	struct idetape_bh *bh = (struct idetape_bh *)rq->special;
	unsigned int length = rq->current_nr_sectors;

Linus Torvalds's avatar
Linus Torvalds committed
876
	idetape_init_pc(pc);
877
	put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
Linus Torvalds's avatar
Linus Torvalds committed
878 879
	pc->c[1] = 1;
	pc->bh = bh;
880 881 882
	pc->buf = NULL;
	pc->buf_size = length * tape->blk_size;
	pc->req_xfer = pc->buf_size;
883
	if (pc->req_xfer == tape->buffer_size)
884
		pc->flags |= PC_FLAG_DMA_OK;
Linus Torvalds's avatar
Linus Torvalds committed
885

886 887 888 889 890 891 892 893 894
	if (opcode == READ_6) {
		pc->c[0] = READ_6;
		atomic_set(&bh->b_count, 0);
	} else if (opcode == WRITE_6) {
		pc->c[0] = WRITE_6;
		pc->flags |= PC_FLAG_WRITING;
		pc->b_data = bh->b_data;
		pc->b_count = atomic_read(&bh->b_count);
	}
895 896

	memcpy(rq->cmd, pc->c, 12);
Linus Torvalds's avatar
Linus Torvalds committed
897 898 899 900 901
}

static ide_startstop_t idetape_do_request(ide_drive_t *drive,
					  struct request *rq, sector_t block)
{
902
	ide_hwif_t *hwif = drive->hwif;
Linus Torvalds's avatar
Linus Torvalds committed
903
	idetape_tape_t *tape = drive->driver_data;
904
	struct ide_atapi_pc *pc = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
905
	struct request *postponed_rq = tape->postponed_rq;
906
	u8 stat;
Linus Torvalds's avatar
Linus Torvalds committed
907

908 909 910 911
	debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %lu,"
			" current_nr_sectors: %u\n",
			(unsigned long long)rq->sector, rq->nr_sectors,
			rq->current_nr_sectors);
Linus Torvalds's avatar
Linus Torvalds committed
912

913
	if (!blk_special_request(rq)) {
914
		/* We do not support buffer cache originated requests. */
Linus Torvalds's avatar
Linus Torvalds committed
915
		printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
916
			"request queue (%d)\n", drive->name, rq->cmd_type);
Linus Torvalds's avatar
Linus Torvalds committed
917 918 919 920
		ide_end_request(drive, 0, 0);
		return ide_stopped;
	}

921
	/* Retry a failed packet command */
922 923 924 925
	if (tape->failed_pc && tape->pc->c[0] == REQUEST_SENSE) {
		pc = tape->failed_pc;
		goto out;
	}
926

Linus Torvalds's avatar
Linus Torvalds committed
927 928 929 930 931 932 933 934 935 936 937 938 939 940
	if (postponed_rq != NULL)
		if (rq != postponed_rq) {
			printk(KERN_ERR "ide-tape: ide-tape.c bug - "
					"Two DSC requests were queued\n");
			idetape_end_request(drive, 0, 0);
			return ide_stopped;
		}

	tape->postponed_rq = NULL;

	/*
	 * If the tape is still busy, postpone our request and service
	 * the other device meanwhile.
	 */
941
	stat = hwif->tp_ops->read_status(hwif);
Linus Torvalds's avatar
Linus Torvalds committed
942

943
	if (!drive->dsc_overlap && !(rq->cmd[13] & REQ_IDETAPE_PC2))
944
		set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
Linus Torvalds's avatar
Linus Torvalds committed
945 946

	if (drive->post_reset == 1) {
947
		set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
Linus Torvalds's avatar
Linus Torvalds committed
948 949 950
		drive->post_reset = 0;
	}

951
	if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) &&
952
	    (stat & ATA_DSC) == 0) {
Linus Torvalds's avatar
Linus Torvalds committed
953 954
		if (postponed_rq == NULL) {
			tape->dsc_polling_start = jiffies;
955
			tape->dsc_poll_freq = tape->best_dsc_rw_freq;
Linus Torvalds's avatar
Linus Torvalds committed
956 957 958 959
			tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
		} else if (time_after(jiffies, tape->dsc_timeout)) {
			printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
				tape->name);
960
			if (rq->cmd[13] & REQ_IDETAPE_PC2) {
Linus Torvalds's avatar
Linus Torvalds committed
961 962 963 964 965
				idetape_media_access_finished(drive);
				return ide_stopped;
			} else {
				return ide_do_reset(drive);
			}
966 967 968
		} else if (time_after(jiffies,
					tape->dsc_polling_start +
					IDETAPE_DSC_MA_THRESHOLD))
969
			tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
Linus Torvalds's avatar
Linus Torvalds committed
970 971 972
		idetape_postpone_request(drive);
		return ide_stopped;
	}
973
	if (rq->cmd[13] & REQ_IDETAPE_READ) {
974
		pc = &tape->queued_pc;
975
		ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
Linus Torvalds's avatar
Linus Torvalds committed
976 977
		goto out;
	}
978
	if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
979
		pc = &tape->queued_pc;
980
		ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
Linus Torvalds's avatar
Linus Torvalds committed
981 982
		goto out;
	}
983
	if (rq->cmd[13] & REQ_IDETAPE_PC1) {
984
		pc = (struct ide_atapi_pc *) rq->buffer;
985 986
		rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
		rq->cmd[13] |= REQ_IDETAPE_PC2;
Linus Torvalds's avatar
Linus Torvalds committed