1 /*
2  * ATAPI support.
3  */
4 
5 #include <linux/kernel.h>
6 #include <linux/cdrom.h>
7 #include <linux/delay.h>
8 #include <linux/export.h>
9 #include <linux/ide.h>
10 #include <linux/scatterlist.h>
11 #include <linux/gfp.h>
12 
13 #include <scsi/scsi.h>
14 
15 #define DRV_NAME "ide-atapi"
16 #define PFX DRV_NAME ": "
17 
18 #ifdef DEBUG
19 #define debug_log(fmt, args...) \
20 	printk(KERN_INFO "ide: " fmt, ## args)
21 #else
22 #define debug_log(fmt, args...) do {} while (0)
23 #endif
24 
25 #define ATAPI_MIN_CDB_BYTES	12
26 
dev_is_idecd(ide_drive_t * drive)27 static inline int dev_is_idecd(ide_drive_t *drive)
28 {
29 	return drive->media == ide_cdrom || drive->media == ide_optical;
30 }
31 
32 /*
33  * Check whether we can support a device,
34  * based on the ATAPI IDENTIFY command results.
35  */
ide_check_atapi_device(ide_drive_t * drive,const char * s)36 int ide_check_atapi_device(ide_drive_t *drive, const char *s)
37 {
38 	u16 *id = drive->id;
39 	u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;
40 
41 	*((u16 *)&gcw) = id[ATA_ID_CONFIG];
42 
43 	protocol    = (gcw[1] & 0xC0) >> 6;
44 	device_type =  gcw[1] & 0x1F;
45 	removable   = (gcw[0] & 0x80) >> 7;
46 	drq_type    = (gcw[0] & 0x60) >> 5;
47 	packet_size =  gcw[0] & 0x03;
48 
49 #ifdef CONFIG_PPC
50 	/* kludge for Apple PowerBook internal zip */
51 	if (drive->media == ide_floppy && device_type == 5 &&
52 	    !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
53 	    strstr((char *)&id[ATA_ID_PROD], "ZIP"))
54 		device_type = 0;
55 #endif
56 
57 	if (protocol != 2)
58 		printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
59 			s, drive->name, protocol);
60 	else if ((drive->media == ide_floppy && device_type != 0) ||
61 		 (drive->media == ide_tape && device_type != 1))
62 		printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
63 			s, drive->name, device_type);
64 	else if (removable == 0)
65 		printk(KERN_ERR "%s: %s: the removable flag is not set\n",
66 			s, drive->name);
67 	else if (drive->media == ide_floppy && drq_type == 3)
68 		printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
69 			"supported\n", s, drive->name, drq_type);
70 	else if (packet_size != 0)
71 		printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
72 			"bytes\n", s, drive->name, packet_size);
73 	else
74 		return 1;
75 	return 0;
76 }
77 EXPORT_SYMBOL_GPL(ide_check_atapi_device);
78 
ide_init_pc(struct ide_atapi_pc * pc)79 void ide_init_pc(struct ide_atapi_pc *pc)
80 {
81 	memset(pc, 0, sizeof(*pc));
82 }
83 EXPORT_SYMBOL_GPL(ide_init_pc);
84 
85 /*
86  * Add a special packet command request to the tail of the request queue,
87  * and wait for it to be serviced.
88  */
ide_queue_pc_tail(ide_drive_t * drive,struct gendisk * disk,struct ide_atapi_pc * pc,void * buf,unsigned int bufflen)89 int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
90 		      struct ide_atapi_pc *pc, void *buf, unsigned int bufflen)
91 {
92 	struct request *rq;
93 	int error;
94 
95 	rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
96 	rq->cmd_type = REQ_TYPE_SPECIAL;
97 	rq->special = (char *)pc;
98 
99 	if (buf && bufflen) {
100 		error = blk_rq_map_kern(drive->queue, rq, buf, bufflen,
101 					GFP_NOIO);
102 		if (error)
103 			goto put_req;
104 	}
105 
106 	memcpy(rq->cmd, pc->c, 12);
107 	if (drive->media == ide_tape)
108 		rq->cmd[13] = REQ_IDETAPE_PC1;
109 	error = blk_execute_rq(drive->queue, disk, rq, 0);
110 put_req:
111 	blk_put_request(rq);
112 	return error;
113 }
114 EXPORT_SYMBOL_GPL(ide_queue_pc_tail);
115 
ide_do_test_unit_ready(ide_drive_t * drive,struct gendisk * disk)116 int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
117 {
118 	struct ide_atapi_pc pc;
119 
120 	ide_init_pc(&pc);
121 	pc.c[0] = TEST_UNIT_READY;
122 
123 	return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
124 }
125 EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);
126 
ide_do_start_stop(ide_drive_t * drive,struct gendisk * disk,int start)127 int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
128 {
129 	struct ide_atapi_pc pc;
130 
131 	ide_init_pc(&pc);
132 	pc.c[0] = START_STOP;
133 	pc.c[4] = start;
134 
135 	if (drive->media == ide_tape)
136 		pc.flags |= PC_FLAG_WAIT_FOR_DSC;
137 
138 	return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
139 }
140 EXPORT_SYMBOL_GPL(ide_do_start_stop);
141 
ide_set_media_lock(ide_drive_t * drive,struct gendisk * disk,int on)142 int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
143 {
144 	struct ide_atapi_pc pc;
145 
146 	if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
147 		return 0;
148 
149 	ide_init_pc(&pc);
150 	pc.c[0] = ALLOW_MEDIUM_REMOVAL;
151 	pc.c[4] = on;
152 
153 	return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
154 }
155 EXPORT_SYMBOL_GPL(ide_set_media_lock);
156 
ide_create_request_sense_cmd(ide_drive_t * drive,struct ide_atapi_pc * pc)157 void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
158 {
159 	ide_init_pc(pc);
160 	pc->c[0] = REQUEST_SENSE;
161 	if (drive->media == ide_floppy) {
162 		pc->c[4] = 255;
163 		pc->req_xfer = 18;
164 	} else {
165 		pc->c[4] = 20;
166 		pc->req_xfer = 20;
167 	}
168 }
169 EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);
170 
ide_prep_sense(ide_drive_t * drive,struct request * rq)171 void ide_prep_sense(ide_drive_t *drive, struct request *rq)
172 {
173 	struct request_sense *sense = &drive->sense_data;
174 	struct request *sense_rq = &drive->sense_rq;
175 	unsigned int cmd_len, sense_len;
176 	int err;
177 
178 	switch (drive->media) {
179 	case ide_floppy:
180 		cmd_len = 255;
181 		sense_len = 18;
182 		break;
183 	case ide_tape:
184 		cmd_len = 20;
185 		sense_len = 20;
186 		break;
187 	default:
188 		cmd_len = 18;
189 		sense_len = 18;
190 	}
191 
192 	BUG_ON(sense_len > sizeof(*sense));
193 
194 	if (rq->cmd_type == REQ_TYPE_SENSE || drive->sense_rq_armed)
195 		return;
196 
197 	memset(sense, 0, sizeof(*sense));
198 
199 	blk_rq_init(rq->q, sense_rq);
200 
201 	err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len,
202 			      GFP_NOIO);
203 	if (unlikely(err)) {
204 		if (printk_ratelimit())
205 			printk(KERN_WARNING PFX "%s: failed to map sense "
206 					    "buffer\n", drive->name);
207 		return;
208 	}
209 
210 	sense_rq->rq_disk = rq->rq_disk;
211 	sense_rq->cmd[0] = GPCMD_REQUEST_SENSE;
212 	sense_rq->cmd[4] = cmd_len;
213 	sense_rq->cmd_type = REQ_TYPE_SENSE;
214 	sense_rq->cmd_flags |= REQ_PREEMPT;
215 
216 	if (drive->media == ide_tape)
217 		sense_rq->cmd[13] = REQ_IDETAPE_PC1;
218 
219 	drive->sense_rq_armed = true;
220 }
221 EXPORT_SYMBOL_GPL(ide_prep_sense);
222 
ide_queue_sense_rq(ide_drive_t * drive,void * special)223 int ide_queue_sense_rq(ide_drive_t *drive, void *special)
224 {
225 	/* deferred failure from ide_prep_sense() */
226 	if (!drive->sense_rq_armed) {
227 		printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
228 		       drive->name);
229 		return -ENOMEM;
230 	}
231 
232 	drive->sense_rq.special = special;
233 	drive->sense_rq_armed = false;
234 
235 	drive->hwif->rq = NULL;
236 
237 	elv_add_request(drive->queue, &drive->sense_rq, ELEVATOR_INSERT_FRONT);
238 	return 0;
239 }
240 EXPORT_SYMBOL_GPL(ide_queue_sense_rq);
241 
242 /*
243  * Called when an error was detected during the last packet command.
244  * We queue a request sense packet command at the head of the request
245  * queue.
246  */
ide_retry_pc(ide_drive_t * drive)247 void ide_retry_pc(ide_drive_t *drive)
248 {
249 	struct request *failed_rq = drive->hwif->rq;
250 	struct request *sense_rq = &drive->sense_rq;
251 	struct ide_atapi_pc *pc = &drive->request_sense_pc;
252 
253 	(void)ide_read_error(drive);
254 
255 	/* init pc from sense_rq */
256 	ide_init_pc(pc);
257 	memcpy(pc->c, sense_rq->cmd, 12);
258 
259 	if (drive->media == ide_tape)
260 		drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
261 
262 	/*
263 	 * Push back the failed request and put request sense on top
264 	 * of it.  The failed command will be retried after sense data
265 	 * is acquired.
266 	 */
267 	drive->hwif->rq = NULL;
268 	ide_requeue_and_plug(drive, failed_rq);
269 	if (ide_queue_sense_rq(drive, pc)) {
270 		blk_start_request(failed_rq);
271 		ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq));
272 	}
273 }
274 EXPORT_SYMBOL_GPL(ide_retry_pc);
275 
ide_cd_expiry(ide_drive_t * drive)276 int ide_cd_expiry(ide_drive_t *drive)
277 {
278 	struct request *rq = drive->hwif->rq;
279 	unsigned long wait = 0;
280 
281 	debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]);
282 
283 	/*
284 	 * Some commands are *slow* and normally take a long time to complete.
285 	 * Usually we can use the ATAPI "disconnect" to bypass this, but not all
286 	 * commands/drives support that. Let ide_timer_expiry keep polling us
287 	 * for these.
288 	 */
289 	switch (rq->cmd[0]) {
290 	case GPCMD_BLANK:
291 	case GPCMD_FORMAT_UNIT:
292 	case GPCMD_RESERVE_RZONE_TRACK:
293 	case GPCMD_CLOSE_TRACK:
294 	case GPCMD_FLUSH_CACHE:
295 		wait = ATAPI_WAIT_PC;
296 		break;
297 	default:
298 		if (!(rq->cmd_flags & REQ_QUIET))
299 			printk(KERN_INFO PFX "cmd 0x%x timed out\n",
300 					 rq->cmd[0]);
301 		wait = 0;
302 		break;
303 	}
304 	return wait;
305 }
306 EXPORT_SYMBOL_GPL(ide_cd_expiry);
307 
ide_cd_get_xferlen(struct request * rq)308 int ide_cd_get_xferlen(struct request *rq)
309 {
310 	switch (rq->cmd_type) {
311 	case REQ_TYPE_FS:
312 		return 32768;
313 	case REQ_TYPE_SENSE:
314 	case REQ_TYPE_BLOCK_PC:
315 	case REQ_TYPE_ATA_PC:
316 		return blk_rq_bytes(rq);
317 	default:
318 		return 0;
319 	}
320 }
321 EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
322 
ide_read_bcount_and_ireason(ide_drive_t * drive,u16 * bcount,u8 * ireason)323 void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
324 {
325 	struct ide_taskfile tf;
326 
327 	drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
328 				     IDE_VALID_LBAM | IDE_VALID_LBAH);
329 
330 	*bcount = (tf.lbah << 8) | tf.lbam;
331 	*ireason = tf.nsect & 3;
332 }
333 EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);
334 
335 /*
336  * Check the contents of the interrupt reason register and attempt to recover if
337  * there are problems.
338  *
339  * Returns:
340  * - 0 if everything's ok
341  * - 1 if the request has to be terminated.
342  */
ide_check_ireason(ide_drive_t * drive,struct request * rq,int len,int ireason,int rw)343 int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
344 		      int ireason, int rw)
345 {
346 	ide_hwif_t *hwif = drive->hwif;
347 
348 	debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);
349 
350 	if (ireason == (!rw << 1))
351 		return 0;
352 	else if (ireason == (rw << 1)) {
353 		printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
354 				drive->name, __func__);
355 
356 		if (dev_is_idecd(drive))
357 			ide_pad_transfer(drive, rw, len);
358 	} else if (!rw && ireason == ATAPI_COD) {
359 		if (dev_is_idecd(drive)) {
360 			/*
361 			 * Some drives (ASUS) seem to tell us that status info
362 			 * is available.  Just get it and ignore.
363 			 */
364 			(void)hwif->tp_ops->read_status(hwif);
365 			return 0;
366 		}
367 	} else {
368 		if (ireason & ATAPI_COD)
369 			printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
370 					__func__);
371 
372 		/* drive wants a command packet, or invalid ireason... */
373 		printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
374 				drive->name, __func__, ireason);
375 	}
376 
377 	if (dev_is_idecd(drive) && rq->cmd_type == REQ_TYPE_ATA_PC)
378 		rq->cmd_flags |= REQ_FAILED;
379 
380 	return 1;
381 }
382 EXPORT_SYMBOL_GPL(ide_check_ireason);
383 
384 /*
385  * This is the usual interrupt handler which will be called during a packet
386  * command.  We will transfer some of the data (as requested by the drive)
387  * and will re-point interrupt handler to us.
388  */
ide_pc_intr(ide_drive_t * drive)389 static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
390 {
391 	struct ide_atapi_pc *pc = drive->pc;
392 	ide_hwif_t *hwif = drive->hwif;
393 	struct ide_cmd *cmd = &hwif->cmd;
394 	struct request *rq = hwif->rq;
395 	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
396 	unsigned int timeout, done;
397 	u16 bcount;
398 	u8 stat, ireason, dsc = 0;
399 	u8 write = !!(pc->flags & PC_FLAG_WRITING);
400 
401 	debug_log("Enter %s - interrupt handler\n", __func__);
402 
403 	timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
404 					       : WAIT_TAPE_CMD;
405 
406 	/* Clear the interrupt */
407 	stat = tp_ops->read_status(hwif);
408 
409 	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
410 		int rc;
411 
412 		drive->waiting_for_dma = 0;
413 		rc = hwif->dma_ops->dma_end(drive);
414 		ide_dma_unmap_sg(drive, cmd);
415 
416 		if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
417 			if (drive->media == ide_floppy)
418 				printk(KERN_ERR PFX "%s: DMA %s error\n",
419 					drive->name, rq_data_dir(pc->rq)
420 						     ? "write" : "read");
421 			pc->flags |= PC_FLAG_DMA_ERROR;
422 		} else
423 			rq->resid_len = 0;
424 		debug_log("%s: DMA finished\n", drive->name);
425 	}
426 
427 	/* No more interrupts */
428 	if ((stat & ATA_DRQ) == 0) {
429 		int uptodate, error;
430 
431 		debug_log("Packet command completed, %d bytes transferred\n",
432 			  blk_rq_bytes(rq));
433 
434 		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
435 
436 		local_irq_enable_in_hardirq();
437 
438 		if (drive->media == ide_tape &&
439 		    (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE)
440 			stat &= ~ATA_ERR;
441 
442 		if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
443 			/* Error detected */
444 			debug_log("%s: I/O error\n", drive->name);
445 
446 			if (drive->media != ide_tape)
447 				pc->rq->errors++;
448 
449 			if (rq->cmd[0] == REQUEST_SENSE) {
450 				printk(KERN_ERR PFX "%s: I/O error in request "
451 						"sense command\n", drive->name);
452 				return ide_do_reset(drive);
453 			}
454 
455 			debug_log("[cmd %x]: check condition\n", rq->cmd[0]);
456 
457 			/* Retry operation */
458 			ide_retry_pc(drive);
459 
460 			/* queued, but not started */
461 			return ide_stopped;
462 		}
463 		pc->error = 0;
464 
465 		if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
466 			dsc = 1;
467 
468 		/*
469 		 * ->pc_callback() might change rq->data_len for
470 		 * residual count, cache total length.
471 		 */
472 		done = blk_rq_bytes(rq);
473 
474 		/* Command finished - Call the callback function */
475 		uptodate = drive->pc_callback(drive, dsc);
476 
477 		if (uptodate == 0)
478 			drive->failed_pc = NULL;
479 
480 		if (rq->cmd_type == REQ_TYPE_SPECIAL) {
481 			rq->errors = 0;
482 			error = 0;
483 		} else {
484 
485 			if (rq->cmd_type != REQ_TYPE_FS && uptodate <= 0) {
486 				if (rq->errors == 0)
487 					rq->errors = -EIO;
488 			}
489 
490 			error = uptodate ? 0 : -EIO;
491 		}
492 
493 		ide_complete_rq(drive, error, blk_rq_bytes(rq));
494 		return ide_stopped;
495 	}
496 
497 	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
498 		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
499 		printk(KERN_ERR PFX "%s: The device wants to issue more "
500 				"interrupts in DMA mode\n", drive->name);
501 		ide_dma_off(drive);
502 		return ide_do_reset(drive);
503 	}
504 
505 	/* Get the number of bytes to transfer on this interrupt. */
506 	ide_read_bcount_and_ireason(drive, &bcount, &ireason);
507 
508 	if (ide_check_ireason(drive, rq, bcount, ireason, write))
509 		return ide_do_reset(drive);
510 
511 	done = min_t(unsigned int, bcount, cmd->nleft);
512 	ide_pio_bytes(drive, cmd, write, done);
513 
514 	/* Update transferred byte count */
515 	rq->resid_len -= done;
516 
517 	bcount -= done;
518 
519 	if (bcount)
520 		ide_pad_transfer(drive, write, bcount);
521 
522 	debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
523 		  rq->cmd[0], done, bcount, rq->resid_len);
524 
525 	/* And set the interrupt handler again */
526 	ide_set_handler(drive, ide_pc_intr, timeout);
527 	return ide_started;
528 }
529 
ide_init_packet_cmd(struct ide_cmd * cmd,u8 valid_tf,u16 bcount,u8 dma)530 static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
531 				u16 bcount, u8 dma)
532 {
533 	cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
534 	cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
535 			    IDE_VALID_FEATURE | valid_tf;
536 	cmd->tf.command = ATA_CMD_PACKET;
537 	cmd->tf.feature = dma;		/* Use PIO/DMA */
538 	cmd->tf.lbam    = bcount & 0xff;
539 	cmd->tf.lbah    = (bcount >> 8) & 0xff;
540 }
541 
ide_read_ireason(ide_drive_t * drive)542 static u8 ide_read_ireason(ide_drive_t *drive)
543 {
544 	struct ide_taskfile tf;
545 
546 	drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);
547 
548 	return tf.nsect & 3;
549 }
550 
ide_wait_ireason(ide_drive_t * drive,u8 ireason)551 static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
552 {
553 	int retries = 100;
554 
555 	while (retries-- && ((ireason & ATAPI_COD) == 0 ||
556 		(ireason & ATAPI_IO))) {
557 		printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
558 				"a packet command, retrying\n", drive->name);
559 		udelay(100);
560 		ireason = ide_read_ireason(drive);
561 		if (retries == 0) {
562 			printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
563 					" a packet command, ignoring\n",
564 					drive->name);
565 			ireason |= ATAPI_COD;
566 			ireason &= ~ATAPI_IO;
567 		}
568 	}
569 
570 	return ireason;
571 }
572 
ide_delayed_transfer_pc(ide_drive_t * drive)573 static int ide_delayed_transfer_pc(ide_drive_t *drive)
574 {
575 	/* Send the actual packet */
576 	drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);
577 
578 	/* Timeout for the packet command */
579 	return WAIT_FLOPPY_CMD;
580 }
581 
ide_transfer_pc(ide_drive_t * drive)582 static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
583 {
584 	struct ide_atapi_pc *uninitialized_var(pc);
585 	ide_hwif_t *hwif = drive->hwif;
586 	struct request *rq = hwif->rq;
587 	ide_expiry_t *expiry;
588 	unsigned int timeout;
589 	int cmd_len;
590 	ide_startstop_t startstop;
591 	u8 ireason;
592 
593 	if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
594 		printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
595 				"DRQ isn't asserted\n", drive->name);
596 		return startstop;
597 	}
598 
599 	if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
600 		if (drive->dma)
601 			drive->waiting_for_dma = 1;
602 	}
603 
604 	if (dev_is_idecd(drive)) {
605 		/* ATAPI commands get padded out to 12 bytes minimum */
606 		cmd_len = COMMAND_SIZE(rq->cmd[0]);
607 		if (cmd_len < ATAPI_MIN_CDB_BYTES)
608 			cmd_len = ATAPI_MIN_CDB_BYTES;
609 
610 		timeout = rq->timeout;
611 		expiry  = ide_cd_expiry;
612 	} else {
613 		pc = drive->pc;
614 
615 		cmd_len = ATAPI_MIN_CDB_BYTES;
616 
617 		/*
618 		 * If necessary schedule the packet transfer to occur 'timeout'
619 		 * milliseconds later in ide_delayed_transfer_pc() after the
620 		 * device says it's ready for a packet.
621 		 */
622 		if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
623 			timeout = drive->pc_delay;
624 			expiry = &ide_delayed_transfer_pc;
625 		} else {
626 			timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
627 							       : WAIT_TAPE_CMD;
628 			expiry = NULL;
629 		}
630 
631 		ireason = ide_read_ireason(drive);
632 		if (drive->media == ide_tape)
633 			ireason = ide_wait_ireason(drive, ireason);
634 
635 		if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
636 			printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
637 				"issuing a packet command\n", drive->name);
638 
639 			return ide_do_reset(drive);
640 		}
641 	}
642 
643 	hwif->expiry = expiry;
644 
645 	/* Set the interrupt routine */
646 	ide_set_handler(drive,
647 			(dev_is_idecd(drive) ? drive->irq_handler
648 					     : ide_pc_intr),
649 			timeout);
650 
651 	/* Send the actual packet */
652 	if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
653 		hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len);
654 
655 	/* Begin DMA, if necessary */
656 	if (dev_is_idecd(drive)) {
657 		if (drive->dma)
658 			hwif->dma_ops->dma_start(drive);
659 	} else {
660 		if (pc->flags & PC_FLAG_DMA_OK) {
661 			pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
662 			hwif->dma_ops->dma_start(drive);
663 		}
664 	}
665 
666 	return ide_started;
667 }
668 
ide_issue_pc(ide_drive_t * drive,struct ide_cmd * cmd)669 ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
670 {
671 	struct ide_atapi_pc *pc;
672 	ide_hwif_t *hwif = drive->hwif;
673 	ide_expiry_t *expiry = NULL;
674 	struct request *rq = hwif->rq;
675 	unsigned int timeout, bytes;
676 	u16 bcount;
677 	u8 valid_tf;
678 	u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);
679 
680 	if (dev_is_idecd(drive)) {
681 		valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
682 		bcount = ide_cd_get_xferlen(rq);
683 		expiry = ide_cd_expiry;
684 		timeout = ATAPI_WAIT_PC;
685 
686 		if (drive->dma)
687 			drive->dma = !ide_dma_prepare(drive, cmd);
688 	} else {
689 		pc = drive->pc;
690 
691 		valid_tf = IDE_VALID_DEVICE;
692 		bytes = blk_rq_bytes(rq);
693 		bcount = ((drive->media == ide_tape) ? bytes
694 						     : min_t(unsigned int,
695 							     bytes, 63 * 1024));
696 
697 		/* We haven't transferred any data yet */
698 		rq->resid_len = bcount;
699 
700 		if (pc->flags & PC_FLAG_DMA_ERROR) {
701 			pc->flags &= ~PC_FLAG_DMA_ERROR;
702 			ide_dma_off(drive);
703 		}
704 
705 		if (pc->flags & PC_FLAG_DMA_OK)
706 			drive->dma = !ide_dma_prepare(drive, cmd);
707 
708 		if (!drive->dma)
709 			pc->flags &= ~PC_FLAG_DMA_OK;
710 
711 		timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
712 						       : WAIT_TAPE_CMD;
713 	}
714 
715 	ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);
716 
717 	(void)do_rw_taskfile(drive, cmd);
718 
719 	if (drq_int) {
720 		if (drive->dma)
721 			drive->waiting_for_dma = 0;
722 		hwif->expiry = expiry;
723 	}
724 
725 	ide_execute_command(drive, cmd, ide_transfer_pc, timeout);
726 
727 	return drq_int ? ide_started : ide_transfer_pc(drive);
728 }
729 EXPORT_SYMBOL_GPL(ide_issue_pc);
730