1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ATAPI support.
4 */
5
6#include <linux/kernel.h>
7#include <linux/cdrom.h>
8#include <linux/delay.h>
9#include <linux/export.h>
10#include <linux/ide.h>
11#include <linux/scatterlist.h>
12#include <linux/gfp.h>
13
14#include <scsi/scsi.h>
15
16#define DRV_NAME "ide-atapi"
17#define PFX DRV_NAME ": "
18
19#ifdef DEBUG
20#define debug_log(fmt, args...) \
21	printk(KERN_INFO "ide: " fmt, ## args)
22#else
23#define debug_log(fmt, args...) do {} while (0)
24#endif
25
26#define ATAPI_MIN_CDB_BYTES	12
27
28static inline int dev_is_idecd(ide_drive_t *drive)
29{
30	return drive->media == ide_cdrom || drive->media == ide_optical;
31}
32
33/*
34 * Check whether we can support a device,
35 * based on the ATAPI IDENTIFY command results.
36 */
37int ide_check_atapi_device(ide_drive_t *drive, const char *s)
38{
39	u16 *id = drive->id;
40	u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;
41
42	*((u16 *)&gcw) = id[ATA_ID_CONFIG];
43
44	protocol    = (gcw[1] & 0xC0) >> 6;
45	device_type =  gcw[1] & 0x1F;
46	removable   = (gcw[0] & 0x80) >> 7;
47	drq_type    = (gcw[0] & 0x60) >> 5;
48	packet_size =  gcw[0] & 0x03;
49
50#ifdef CONFIG_PPC
51	/* kludge for Apple PowerBook internal zip */
52	if (drive->media == ide_floppy && device_type == 5 &&
53	    !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
54	    strstr((char *)&id[ATA_ID_PROD], "ZIP"))
55		device_type = 0;
56#endif
57
58	if (protocol != 2)
59		printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
60			s, drive->name, protocol);
61	else if ((drive->media == ide_floppy && device_type != 0) ||
62		 (drive->media == ide_tape && device_type != 1))
63		printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
64			s, drive->name, device_type);
65	else if (removable == 0)
66		printk(KERN_ERR "%s: %s: the removable flag is not set\n",
67			s, drive->name);
68	else if (drive->media == ide_floppy && drq_type == 3)
69		printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
70			"supported\n", s, drive->name, drq_type);
71	else if (packet_size != 0)
72		printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
73			"bytes\n", s, drive->name, packet_size);
74	else
75		return 1;
76	return 0;
77}
78EXPORT_SYMBOL_GPL(ide_check_atapi_device);
79
80void ide_init_pc(struct ide_atapi_pc *pc)
81{
82	memset(pc, 0, sizeof(*pc));
83}
84EXPORT_SYMBOL_GPL(ide_init_pc);
85
86/*
87 * Add a special packet command request to the tail of the request queue,
88 * and wait for it to be serviced.
89 */
90int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
91		      struct ide_atapi_pc *pc, void *buf, unsigned int bufflen)
92{
93	struct request *rq;
94	int error;
95
96	rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, 0);
97	ide_req(rq)->type = ATA_PRIV_MISC;
98	ide_req(rq)->special = pc;
99
100	if (buf && bufflen) {
101		error = blk_rq_map_kern(drive->queue, rq, buf, bufflen,
102					GFP_NOIO);
103		if (error)
104			goto put_req;
105	}
106
107	memcpy(scsi_req(rq)->cmd, pc->c, 12);
108	if (drive->media == ide_tape)
109		scsi_req(rq)->cmd[13] = REQ_IDETAPE_PC1;
110	blk_execute_rq(drive->queue, disk, rq, 0);
111	error = scsi_req(rq)->result ? -EIO : 0;
112put_req:
113	blk_put_request(rq);
114	return error;
115}
116EXPORT_SYMBOL_GPL(ide_queue_pc_tail);
117
118int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
119{
120	struct ide_atapi_pc pc;
121
122	ide_init_pc(&pc);
123	pc.c[0] = TEST_UNIT_READY;
124
125	return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
126}
127EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);
128
129int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
130{
131	struct ide_atapi_pc pc;
132
133	ide_init_pc(&pc);
134	pc.c[0] = START_STOP;
135	pc.c[4] = start;
136
137	if (drive->media == ide_tape)
138		pc.flags |= PC_FLAG_WAIT_FOR_DSC;
139
140	return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
141}
142EXPORT_SYMBOL_GPL(ide_do_start_stop);
143
144int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
145{
146	struct ide_atapi_pc pc;
147
148	if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
149		return 0;
150
151	ide_init_pc(&pc);
152	pc.c[0] = ALLOW_MEDIUM_REMOVAL;
153	pc.c[4] = on;
154
155	return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
156}
157EXPORT_SYMBOL_GPL(ide_set_media_lock);
158
159void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
160{
161	ide_init_pc(pc);
162	pc->c[0] = REQUEST_SENSE;
163	if (drive->media == ide_floppy) {
164		pc->c[4] = 255;
165		pc->req_xfer = 18;
166	} else {
167		pc->c[4] = 20;
168		pc->req_xfer = 20;
169	}
170}
171EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);
172
173void ide_prep_sense(ide_drive_t *drive, struct request *rq)
174{
175	struct request_sense *sense = &drive->sense_data;
176	struct request *sense_rq;
177	struct scsi_request *req;
178	unsigned int cmd_len, sense_len;
179	int err;
180
181	switch (drive->media) {
182	case ide_floppy:
183		cmd_len = 255;
184		sense_len = 18;
185		break;
186	case ide_tape:
187		cmd_len = 20;
188		sense_len = 20;
189		break;
190	default:
191		cmd_len = 18;
192		sense_len = 18;
193	}
194
195	BUG_ON(sense_len > sizeof(*sense));
196
197	if (ata_sense_request(rq) || drive->sense_rq_armed)
198		return;
199
200	sense_rq = drive->sense_rq;
201	if (!sense_rq) {
202		sense_rq = blk_mq_alloc_request(drive->queue, REQ_OP_DRV_IN,
203					BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
204		drive->sense_rq = sense_rq;
205	}
206	req = scsi_req(sense_rq);
207
208	memset(sense, 0, sizeof(*sense));
209
210	scsi_req_init(req);
211
212	err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len,
213			      GFP_NOIO);
214	if (unlikely(err)) {
215		if (printk_ratelimit())
216			printk(KERN_WARNING PFX "%s: failed to map sense "
217					    "buffer\n", drive->name);
218		blk_mq_free_request(sense_rq);
219		drive->sense_rq = NULL;
220		return;
221	}
222
223	sense_rq->rq_disk = rq->rq_disk;
224	sense_rq->cmd_flags = REQ_OP_DRV_IN;
225	ide_req(sense_rq)->type = ATA_PRIV_SENSE;
226
227	req->cmd[0] = GPCMD_REQUEST_SENSE;
228	req->cmd[4] = cmd_len;
229	if (drive->media == ide_tape)
230		req->cmd[13] = REQ_IDETAPE_PC1;
231
232	drive->sense_rq_armed = true;
233}
234EXPORT_SYMBOL_GPL(ide_prep_sense);
235
236int ide_queue_sense_rq(ide_drive_t *drive, void *special)
237{
238	ide_hwif_t *hwif = drive->hwif;
239	struct request *sense_rq;
240	unsigned long flags;
241
242	spin_lock_irqsave(&hwif->lock, flags);
243
244	/* deferred failure from ide_prep_sense() */
245	if (!drive->sense_rq_armed) {
246		printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
247		       drive->name);
248		spin_unlock_irqrestore(&hwif->lock, flags);
249		return -ENOMEM;
250	}
251
252	sense_rq = drive->sense_rq;
253	ide_req(sense_rq)->special = special;
254	drive->sense_rq_armed = false;
255
256	drive->hwif->rq = NULL;
257
258	ide_insert_request_head(drive, sense_rq);
259	spin_unlock_irqrestore(&hwif->lock, flags);
260	return 0;
261}
262EXPORT_SYMBOL_GPL(ide_queue_sense_rq);
263
264/*
265 * Called when an error was detected during the last packet command.
266 * We queue a request sense packet command at the head of the request
267 * queue.
268 */
269void ide_retry_pc(ide_drive_t *drive)
270{
271	struct request *failed_rq = drive->hwif->rq;
272	struct request *sense_rq = drive->sense_rq;
273	struct ide_atapi_pc *pc = &drive->request_sense_pc;
274
275	(void)ide_read_error(drive);
276
277	/* init pc from sense_rq */
278	ide_init_pc(pc);
279	memcpy(pc->c, scsi_req(sense_rq)->cmd, 12);
280
281	if (drive->media == ide_tape)
282		drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
283
284	/*
285	 * Push back the failed request and put request sense on top
286	 * of it.  The failed command will be retried after sense data
287	 * is acquired.
288	 */
289	drive->hwif->rq = NULL;
290	ide_requeue_and_plug(drive, failed_rq);
291	if (ide_queue_sense_rq(drive, pc))
292		ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(failed_rq));
293}
294EXPORT_SYMBOL_GPL(ide_retry_pc);
295
296int ide_cd_expiry(ide_drive_t *drive)
297{
298	struct request *rq = drive->hwif->rq;
299	unsigned long wait = 0;
300
301	debug_log("%s: scsi_req(rq)->cmd[0]: 0x%x\n", __func__, scsi_req(rq)->cmd[0]);
302
303	/*
304	 * Some commands are *slow* and normally take a long time to complete.
305	 * Usually we can use the ATAPI "disconnect" to bypass this, but not all
306	 * commands/drives support that. Let ide_timer_expiry keep polling us
307	 * for these.
308	 */
309	switch (scsi_req(rq)->cmd[0]) {
310	case GPCMD_BLANK:
311	case GPCMD_FORMAT_UNIT:
312	case GPCMD_RESERVE_RZONE_TRACK:
313	case GPCMD_CLOSE_TRACK:
314	case GPCMD_FLUSH_CACHE:
315		wait = ATAPI_WAIT_PC;
316		break;
317	default:
318		if (!(rq->rq_flags & RQF_QUIET))
319			printk(KERN_INFO PFX "cmd 0x%x timed out\n",
320					 scsi_req(rq)->cmd[0]);
321		wait = 0;
322		break;
323	}
324	return wait;
325}
326EXPORT_SYMBOL_GPL(ide_cd_expiry);
327
328int ide_cd_get_xferlen(struct request *rq)
329{
330	switch (req_op(rq)) {
331	default:
332		return 32768;
333	case REQ_OP_SCSI_IN:
334	case REQ_OP_SCSI_OUT:
335		return blk_rq_bytes(rq);
336	case REQ_OP_DRV_IN:
337	case REQ_OP_DRV_OUT:
338		switch (ide_req(rq)->type) {
339		case ATA_PRIV_PC:
340		case ATA_PRIV_SENSE:
341			return blk_rq_bytes(rq);
342		default:
343			return 0;
344		}
345	}
346}
347EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
348
349void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
350{
351	struct ide_taskfile tf;
352
353	drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
354				     IDE_VALID_LBAM | IDE_VALID_LBAH);
355
356	*bcount = (tf.lbah << 8) | tf.lbam;
357	*ireason = tf.nsect & 3;
358}
359EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);
360
361/*
362 * Check the contents of the interrupt reason register and attempt to recover if
363 * there are problems.
364 *
365 * Returns:
366 * - 0 if everything's ok
367 * - 1 if the request has to be terminated.
368 */
369int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
370		      int ireason, int rw)
371{
372	ide_hwif_t *hwif = drive->hwif;
373
374	debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);
375
376	if (ireason == (!rw << 1))
377		return 0;
378	else if (ireason == (rw << 1)) {
379		printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
380				drive->name, __func__);
381
382		if (dev_is_idecd(drive))
383			ide_pad_transfer(drive, rw, len);
384	} else if (!rw && ireason == ATAPI_COD) {
385		if (dev_is_idecd(drive)) {
386			/*
387			 * Some drives (ASUS) seem to tell us that status info
388			 * is available.  Just get it and ignore.
389			 */
390			(void)hwif->tp_ops->read_status(hwif);
391			return 0;
392		}
393	} else {
394		if (ireason & ATAPI_COD)
395			printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
396					__func__);
397
398		/* drive wants a command packet, or invalid ireason... */
399		printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
400				drive->name, __func__, ireason);
401	}
402
403	if (dev_is_idecd(drive) && ata_pc_request(rq))
404		rq->rq_flags |= RQF_FAILED;
405
406	return 1;
407}
408EXPORT_SYMBOL_GPL(ide_check_ireason);
409
410/*
411 * This is the usual interrupt handler which will be called during a packet
412 * command.  We will transfer some of the data (as requested by the drive)
413 * and will re-point interrupt handler to us.
414 */
415static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
416{
417	struct ide_atapi_pc *pc = drive->pc;
418	ide_hwif_t *hwif = drive->hwif;
419	struct ide_cmd *cmd = &hwif->cmd;
420	struct request *rq = hwif->rq;
421	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
422	unsigned int timeout, done;
423	u16 bcount;
424	u8 stat, ireason, dsc = 0;
425	u8 write = !!(pc->flags & PC_FLAG_WRITING);
426
427	debug_log("Enter %s - interrupt handler\n", __func__);
428
429	timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
430					       : WAIT_TAPE_CMD;
431
432	/* Clear the interrupt */
433	stat = tp_ops->read_status(hwif);
434
435	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
436		int rc;
437
438		drive->waiting_for_dma = 0;
439		rc = hwif->dma_ops->dma_end(drive);
440		ide_dma_unmap_sg(drive, cmd);
441
442		if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
443			if (drive->media == ide_floppy)
444				printk(KERN_ERR PFX "%s: DMA %s error\n",
445					drive->name, rq_data_dir(pc->rq)
446						     ? "write" : "read");
447			pc->flags |= PC_FLAG_DMA_ERROR;
448		} else
449			scsi_req(rq)->resid_len = 0;
450		debug_log("%s: DMA finished\n", drive->name);
451	}
452
453	/* No more interrupts */
454	if ((stat & ATA_DRQ) == 0) {
455		int uptodate;
456		blk_status_t error;
457
458		debug_log("Packet command completed, %d bytes transferred\n",
459			  blk_rq_bytes(rq));
460
461		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
462
463		local_irq_enable_in_hardirq();
464
465		if (drive->media == ide_tape &&
466		    (stat & ATA_ERR) && scsi_req(rq)->cmd[0] == REQUEST_SENSE)
467			stat &= ~ATA_ERR;
468
469		if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
470			/* Error detected */
471			debug_log("%s: I/O error\n", drive->name);
472
473			if (drive->media != ide_tape)
474				scsi_req(pc->rq)->result++;
475
476			if (scsi_req(rq)->cmd[0] == REQUEST_SENSE) {
477				printk(KERN_ERR PFX "%s: I/O error in request "
478						"sense command\n", drive->name);
479				return ide_do_reset(drive);
480			}
481
482			debug_log("[cmd %x]: check condition\n", scsi_req(rq)->cmd[0]);
483
484			/* Retry operation */
485			ide_retry_pc(drive);
486
487			/* queued, but not started */
488			return ide_stopped;
489		}
490		pc->error = 0;
491
492		if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
493			dsc = 1;
494
495		/*
496		 * ->pc_callback() might change rq->data_len for
497		 * residual count, cache total length.
498		 */
499		done = blk_rq_bytes(rq);
500
501		/* Command finished - Call the callback function */
502		uptodate = drive->pc_callback(drive, dsc);
503
504		if (uptodate == 0)
505			drive->failed_pc = NULL;
506
507		if (ata_misc_request(rq)) {
508			scsi_req(rq)->result = 0;
509			error = BLK_STS_OK;
510		} else {
511
512			if (blk_rq_is_passthrough(rq) && uptodate <= 0) {
513				if (scsi_req(rq)->result == 0)
514					scsi_req(rq)->result = -EIO;
515			}
516
517			error = uptodate ? BLK_STS_OK : BLK_STS_IOERR;
518		}
519
520		ide_complete_rq(drive, error, blk_rq_bytes(rq));
521		return ide_stopped;
522	}
523
524	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
525		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
526		printk(KERN_ERR PFX "%s: The device wants to issue more "
527				"interrupts in DMA mode\n", drive->name);
528		ide_dma_off(drive);
529		return ide_do_reset(drive);
530	}
531
532	/* Get the number of bytes to transfer on this interrupt. */
533	ide_read_bcount_and_ireason(drive, &bcount, &ireason);
534
535	if (ide_check_ireason(drive, rq, bcount, ireason, write))
536		return ide_do_reset(drive);
537
538	done = min_t(unsigned int, bcount, cmd->nleft);
539	ide_pio_bytes(drive, cmd, write, done);
540
541	/* Update transferred byte count */
542	scsi_req(rq)->resid_len -= done;
543
544	bcount -= done;
545
546	if (bcount)
547		ide_pad_transfer(drive, write, bcount);
548
549	debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
550		  scsi_req(rq)->cmd[0], done, bcount, scsi_req(rq)->resid_len);
551
552	/* And set the interrupt handler again */
553	ide_set_handler(drive, ide_pc_intr, timeout);
554	return ide_started;
555}
556
557static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
558				u16 bcount, u8 dma)
559{
560	cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
561	cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
562			    IDE_VALID_FEATURE | valid_tf;
563	cmd->tf.command = ATA_CMD_PACKET;
564	cmd->tf.feature = dma;		/* Use PIO/DMA */
565	cmd->tf.lbam    = bcount & 0xff;
566	cmd->tf.lbah    = (bcount >> 8) & 0xff;
567}
568
569static u8 ide_read_ireason(ide_drive_t *drive)
570{
571	struct ide_taskfile tf;
572
573	drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);
574
575	return tf.nsect & 3;
576}
577
578static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
579{
580	int retries = 100;
581
582	while (retries-- && ((ireason & ATAPI_COD) == 0 ||
583		(ireason & ATAPI_IO))) {
584		printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
585				"a packet command, retrying\n", drive->name);
586		udelay(100);
587		ireason = ide_read_ireason(drive);
588		if (retries == 0) {
589			printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
590					" a packet command, ignoring\n",
591					drive->name);
592			ireason |= ATAPI_COD;
593			ireason &= ~ATAPI_IO;
594		}
595	}
596
597	return ireason;
598}
599
600static int ide_delayed_transfer_pc(ide_drive_t *drive)
601{
602	/* Send the actual packet */
603	drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);
604
605	/* Timeout for the packet command */
606	return WAIT_FLOPPY_CMD;
607}
608
609static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
610{
611	struct ide_atapi_pc *pc;
612	ide_hwif_t *hwif = drive->hwif;
613	struct request *rq = hwif->rq;
614	ide_expiry_t *expiry;
615	unsigned int timeout;
616	int cmd_len;
617	ide_startstop_t startstop;
618	u8 ireason;
619
620	if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
621		printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
622				"DRQ isn't asserted\n", drive->name);
623		return startstop;
624	}
625
626	if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
627		if (drive->dma)
628			drive->waiting_for_dma = 1;
629	}
630
631	if (dev_is_idecd(drive)) {
632		/* ATAPI commands get padded out to 12 bytes minimum */
633		cmd_len = COMMAND_SIZE(scsi_req(rq)->cmd[0]);
634		if (cmd_len < ATAPI_MIN_CDB_BYTES)
635			cmd_len = ATAPI_MIN_CDB_BYTES;
636
637		timeout = rq->timeout;
638		expiry  = ide_cd_expiry;
639	} else {
640		pc = drive->pc;
641
642		cmd_len = ATAPI_MIN_CDB_BYTES;
643
644		/*
645		 * If necessary schedule the packet transfer to occur 'timeout'
646		 * milliseconds later in ide_delayed_transfer_pc() after the
647		 * device says it's ready for a packet.
648		 */
649		if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
650			timeout = drive->pc_delay;
651			expiry = &ide_delayed_transfer_pc;
652		} else {
653			timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
654							       : WAIT_TAPE_CMD;
655			expiry = NULL;
656		}
657
658		ireason = ide_read_ireason(drive);
659		if (drive->media == ide_tape)
660			ireason = ide_wait_ireason(drive, ireason);
661
662		if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
663			printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
664				"issuing a packet command\n", drive->name);
665
666			return ide_do_reset(drive);
667		}
668	}
669
670	hwif->expiry = expiry;
671
672	/* Set the interrupt routine */
673	ide_set_handler(drive,
674			(dev_is_idecd(drive) ? drive->irq_handler
675					     : ide_pc_intr),
676			timeout);
677
678	/* Send the actual packet */
679	if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
680		hwif->tp_ops->output_data(drive, NULL, scsi_req(rq)->cmd, cmd_len);
681
682	/* Begin DMA, if necessary */
683	if (dev_is_idecd(drive)) {
684		if (drive->dma)
685			hwif->dma_ops->dma_start(drive);
686	} else {
687		if (pc->flags & PC_FLAG_DMA_OK) {
688			pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
689			hwif->dma_ops->dma_start(drive);
690		}
691	}
692
693	return ide_started;
694}
695
696ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
697{
698	struct ide_atapi_pc *pc;
699	ide_hwif_t *hwif = drive->hwif;
700	ide_expiry_t *expiry = NULL;
701	struct request *rq = hwif->rq;
702	unsigned int timeout, bytes;
703	u16 bcount;
704	u8 valid_tf;
705	u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);
706
707	if (dev_is_idecd(drive)) {
708		valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
709		bcount = ide_cd_get_xferlen(rq);
710		expiry = ide_cd_expiry;
711		timeout = ATAPI_WAIT_PC;
712
713		if (drive->dma)
714			drive->dma = !ide_dma_prepare(drive, cmd);
715	} else {
716		pc = drive->pc;
717
718		valid_tf = IDE_VALID_DEVICE;
719		bytes = blk_rq_bytes(rq);
720		bcount = ((drive->media == ide_tape) ? bytes
721						     : min_t(unsigned int,
722							     bytes, 63 * 1024));
723
724		/* We haven't transferred any data yet */
725		scsi_req(rq)->resid_len = bcount;
726
727		if (pc->flags & PC_FLAG_DMA_ERROR) {
728			pc->flags &= ~PC_FLAG_DMA_ERROR;
729			ide_dma_off(drive);
730		}
731
732		if (pc->flags & PC_FLAG_DMA_OK)
733			drive->dma = !ide_dma_prepare(drive, cmd);
734
735		if (!drive->dma)
736			pc->flags &= ~PC_FLAG_DMA_OK;
737
738		timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
739						       : WAIT_TAPE_CMD;
740	}
741
742	ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);
743
744	(void)do_rw_taskfile(drive, cmd);
745
746	if (drq_int) {
747		if (drive->dma)
748			drive->waiting_for_dma = 0;
749		hwif->expiry = expiry;
750	}
751
752	ide_execute_command(drive, cmd, ide_transfer_pc, timeout);
753
754	return drq_int ? ide_started : ide_transfer_pc(drive);
755}
756EXPORT_SYMBOL_GPL(ide_issue_pc);
757