aboutsummaryrefslogtreecommitdiff
path: root/drivers/ata/sata_qstor.c
blob: 2ceb0990bcd899a384a0443a762059eb4e066118 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
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
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
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
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
/*
 *  sata_qstor.c - Pacific Digital Corporation QStor SATA
 *
 *  Maintained by:  Mark Lord <mlord@pobox.com>
 *
 *  Copyright 2005 Pacific Digital Corporation.
 *  (OSL/GPL code release authorized by Jalil Fadavi).
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 *  libata documentation is available via 'make {ps|pdf}docs',
 *  as Documentation/DocBook/libata.*
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>

#define DRV_NAME	"sata_qstor"
#define DRV_VERSION	"0.09"

enum {
	QS_MMIO_BAR		= 4,

	QS_PORTS		= 4,
	QS_MAX_PRD		= LIBATA_MAX_PRD,
	QS_CPB_ORDER		= 6,
	QS_CPB_BYTES		= (1 << QS_CPB_ORDER),
	QS_PRD_BYTES		= QS_MAX_PRD * 16,
	QS_PKT_BYTES		= QS_CPB_BYTES + QS_PRD_BYTES,

	/* global register offsets */
	QS_HCF_CNFG3		= 0x0003, /* host configuration offset */
	QS_HID_HPHY		= 0x0004, /* host physical interface info */
	QS_HCT_CTRL		= 0x00e4, /* global interrupt mask offset */
	QS_HST_SFF		= 0x0100, /* host status fifo offset */
	QS_HVS_SERD3		= 0x0393, /* PHY enable offset */

	/* global control bits */
	QS_HPHY_64BIT		= (1 << 1), /* 64-bit bus detected */
	QS_CNFG3_GSRST		= 0x01,     /* global chip reset */
	QS_SERD3_PHY_ENA	= 0xf0,     /* PHY detection ENAble*/

	/* per-channel register offsets */
	QS_CCF_CPBA		= 0x0710, /* chan CPB base address */
	QS_CCF_CSEP		= 0x0718, /* chan CPB separation factor */
	QS_CFC_HUFT		= 0x0800, /* host upstream fifo threshold */
	QS_CFC_HDFT		= 0x0804, /* host downstream fifo threshold */
	QS_CFC_DUFT		= 0x0808, /* dev upstream fifo threshold */
	QS_CFC_DDFT		= 0x080c, /* dev downstream fifo threshold */
	QS_CCT_CTR0		= 0x0900, /* chan control-0 offset */
	QS_CCT_CTR1		= 0x0901, /* chan control-1 offset */
	QS_CCT_CFF		= 0x0a00, /* chan command fifo offset */

	/* channel control bits */
	QS_CTR0_REG		= (1 << 1),   /* register mode (vs. pkt mode) */
	QS_CTR0_CLER		= (1 << 2),   /* clear channel errors */
	QS_CTR1_RDEV		= (1 << 1),   /* sata phy/comms reset */
	QS_CTR1_RCHN		= (1 << 4),   /* reset channel logic */
	QS_CCF_RUN_PKT		= 0x107,      /* RUN a new dma PKT */

	/* pkt sub-field headers */
	QS_HCB_HDR		= 0x01,   /* Host Control Block header */
	QS_DCB_HDR		= 0x02,   /* Device Control Block header */

	/* pkt HCB flag bits */
	QS_HF_DIRO		= (1 << 0),   /* data DIRection Out */
	QS_HF_DAT		= (1 << 3),   /* DATa pkt */
	QS_HF_IEN		= (1 << 4),   /* Interrupt ENable */
	QS_HF_VLD		= (1 << 5),   /* VaLiD pkt */

	/* pkt DCB flag bits */
	QS_DF_PORD		= (1 << 2),   /* Pio OR Dma */
	QS_DF_ELBA		= (1 << 3),   /* Extended LBA (lba48) */

	/* PCI device IDs */
	board_2068_idx		= 0,	/* QStor 4-port SATA/RAID */
};

enum {
	QS_DMA_BOUNDARY		= ~0UL
};

typedef enum { qs_state_mmio, qs_state_pkt } qs_state_t;

struct qs_port_priv {
	u8			*pkt;
	dma_addr_t		pkt_dma;
	qs_state_t		state;
};

static int qs_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
static int qs_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
static int qs_ata_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
static int qs_port_start(struct ata_port *ap);
static void qs_host_stop(struct ata_host *host);
static void qs_qc_prep(struct ata_queued_cmd *qc);
static unsigned int qs_qc_issue(struct ata_queued_cmd *qc);
static int qs_check_atapi_dma(struct ata_queued_cmd *qc);
static void qs_bmdma_stop(struct ata_queued_cmd *qc);
static u8 qs_bmdma_status(struct ata_port *ap);
static void qs_freeze(struct ata_port *ap);
static void qs_thaw(struct ata_port *ap);
static int qs_prereset(struct ata_link *link, unsigned long deadline);
static void qs_error_handler(struct ata_port *ap);

static struct scsi_host_template qs_ata_sht = {
	ATA_BASE_SHT(DRV_NAME),
	.sg_tablesize		= QS_MAX_PRD,
	.dma_boundary		= QS_DMA_BOUNDARY,
};

static struct ata_port_operations qs_ata_ops = {
	.inherits		= &ata_sff_port_ops,

	.check_atapi_dma	= qs_check_atapi_dma,
	.bmdma_stop		= qs_bmdma_stop,
	.bmdma_status		= qs_bmdma_status,
	.qc_prep		= qs_qc_prep,
	.qc_issue		= qs_qc_issue,

	.freeze			= qs_freeze,
	.thaw			= qs_thaw,
	.prereset		= qs_prereset,
	.softreset		= ATA_OP_NULL,
	.error_handler		= qs_error_handler,
	.post_internal_cmd	= ATA_OP_NULL,

	.scr_read		= qs_scr_read,
	.scr_write		= qs_scr_write,

	.port_start		= qs_port_start,
	.host_stop		= qs_host_stop,
};

static const struct ata_port_info qs_port_info[] = {
	/* board_2068_idx */
	{
		.flags		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
				  ATA_FLAG_MMIO | ATA_FLAG_PIO_POLLING,
		.pio_mask	= 0x10, /* pio4 */
		.udma_mask	= ATA_UDMA6,
		.port_ops	= &qs_ata_ops,
	},
};

static const struct pci_device_id qs_ata_pci_tbl[] = {
	{ PCI_VDEVICE(PDC, 0x2068), board_2068_idx },

	{ }	/* terminate list */
};

static struct pci_driver qs_ata_pci_driver = {
	.name			= DRV_NAME,
	.id_table		= qs_ata_pci_tbl,
	.probe			= qs_ata_init_one,
	.remove			= ata_pci_remove_one,
};

static void __iomem *qs_mmio_base(struct ata_host *host)
{
	return host->iomap[QS_MMIO_BAR];
}

static int qs_check_atapi_dma(struct ata_queued_cmd *qc)
{
	return 1;	/* ATAPI DMA not supported */
}

static void qs_bmdma_stop(struct ata_queued_cmd *qc)
{
	/* nothing */
}

static u8 qs_bmdma_status(struct ata_port *ap)
{
	return 0;
}

static inline void qs_enter_reg_mode(struct ata_port *ap)
{
	u8 __iomem *chan = qs_mmio_base(ap->host) + (ap->port_no * 0x4000);
	struct qs_port_priv *pp = ap->private_data;

	pp->state = qs_state_mmio;
	writeb(QS_CTR0_REG, chan + QS_CCT_CTR0);
	readb(chan + QS_CCT_CTR0);        /* flush */
}

static inline void qs_reset_channel_logic(struct ata_port *ap)
{
	u8 __iomem *chan = qs_mmio_base(ap->host) + (ap->port_no * 0x4000);

	writeb(QS_CTR1_RCHN, chan + QS_CCT_CTR1);
	readb(chan + QS_CCT_CTR0);        /* flush */
	qs_enter_reg_mode(ap);
}

static void qs_freeze(struct ata_port *ap)
{
	u8 __iomem *mmio_base = qs_mmio_base(ap->host);

	writeb(0, mmio_base + QS_HCT_CTRL); /* disable host interrupts */
	qs_enter_reg_mode(ap);
}

static void qs_thaw(struct ata_port *ap)
{
	u8 __iomem *mmio_base = qs_mmio_base(ap->host);

	qs_enter_reg_mode(ap);
	writeb(1, mmio_base + QS_HCT_CTRL); /* enable host interrupts */
}

static int qs_prereset(struct ata_link *link, unsigned long deadline)
{
	struct ata_port *ap = link->ap;

	qs_reset_channel_logic(ap);
	return ata_std_prereset(link, deadline);
}

static int qs_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
{
	if (sc_reg > SCR_CONTROL)
		return -EINVAL;
	*val = readl(ap->ioaddr.scr_addr + (sc_reg * 8));
	return 0;
}

static void qs_error_handler(struct ata_port *ap)
{
	qs_enter_reg_mode(ap);
	ata_std_error_handler(ap);
}

static int qs_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
{
	if (sc_reg > SCR_CONTROL)
		return -EINVAL;
	writel(val, ap->ioaddr.scr_addr + (sc_reg * 8));
	return 0;
}

static unsigned int qs_fill_sg(struct ata_queued_cmd *qc)
{
	struct scatterlist *sg;
	struct ata_port *ap = qc->ap;
	struct qs_port_priv *pp = ap->private_data;
	u8 *prd = pp->pkt + QS_CPB_BYTES;
	unsigned int si;

	for_each_sg(qc->sg, sg, qc->n_elem, si) {
		u64 addr;
		u32 len;

		addr = sg_dma_address(sg);
		*(__le64 *)prd = cpu_to_le64(addr);
		prd += sizeof(u64);

		len = sg_dma_len(sg);
		*(__le32 *)prd = cpu_to_le32(len);
		prd += sizeof(u64);

		VPRINTK("PRD[%u] = (0x%llX, 0x%X)\n", si,
					(unsigned long long)addr, len);
	}

	return si;
}

static void qs_qc_prep(struct ata_queued_cmd *qc)
{
	struct qs_port_priv *pp = qc->ap->private_data;
	u8 dflags = QS_DF_PORD, *buf = pp->pkt;
	u8 hflags = QS_HF_DAT | QS_HF_IEN | QS_HF_VLD;
	u64 addr;
	unsigned int nelem;

	VPRINTK("ENTER\n");

	qs_enter_reg_mode(qc->ap);
	if (qc->tf.protocol != ATA_PROT_DMA) {
		ata_qc_prep(qc);
		return;
	}

	nelem = qs_fill_sg(qc);

	if ((qc->tf.flags & ATA_TFLAG_WRITE))
		hflags |= QS_HF_DIRO;
	if ((qc->tf.flags & ATA_TFLAG_LBA48))
		dflags |= QS_DF_ELBA;

	/* host control block (HCB) */
	buf[ 0] = QS_HCB_HDR;
	buf[ 1] = hflags;
	*(__le32 *)(&buf[ 4]) = cpu_to_le32(qc->nbytes);
	*(__le32 *)(&buf[ 8]) = cpu_to_le32(nelem);
	addr = ((u64)pp->pkt_dma) + QS_CPB_BYTES;
	*(__le64 *)(&buf[16]) = cpu_to_le64(addr);

	/* device control block (DCB) */
	buf[24] = QS_DCB_HDR;
	buf[28] = dflags;

	/* frame information structure (FIS) */
	ata_tf_to_fis(&qc->tf, 0, 1, &buf[32]);
}

static inline void qs_packet_start(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	u8 __iomem *chan = qs_mmio_base(ap->host) + (ap->port_no * 0x4000);

	VPRINTK("ENTER, ap %p\n", ap);

	writeb(QS_CTR0_CLER, chan + QS_CCT_CTR0);
	wmb();                             /* flush PRDs and pkt to memory */
	writel(QS_CCF_RUN_PKT, chan + QS_CCT_CFF);
	readl(chan + QS_CCT_CFF);          /* flush */
}

static unsigned int qs_qc_issue(struct ata_queued_cmd *qc)
{
	struct qs_port_priv *pp = qc->ap->private_data;

	switch (qc->tf.protocol) {
	case ATA_PROT_DMA:
		pp->state = qs_state_pkt;
		qs_packet_start(qc);
		return 0;

	case ATAPI_PROT_DMA:
		BUG();
		break;

	default:
		break;
	}

	pp->state = qs_state_mmio;
	return ata_qc_issue_prot(qc);
}

static void qs_do_or_die(struct ata_queued_cmd *qc, u8 status)
{
	qc->err_mask |= ac_err_mask(status);

	if (!qc->err_mask) {
		ata_qc_complete(qc);
	} else {
		struct ata_port    *ap  = qc->ap;
		struct ata_eh_info *ehi = &ap->link.eh_info;

		ata_ehi_clear_desc(ehi);
		ata_ehi_push_desc(ehi, "status 0x%02X", status);

		if (qc->err_mask == AC_ERR_DEV)
			ata_port_abort(ap);
		else
			ata_port_freeze(ap);
	}
}

static inline unsigned int qs_intr_pkt(struct ata_host *host)
{
	unsigned int handled = 0;
	u8 sFFE;
	u8 __iomem *mmio_base = qs_mmio_base(host);

	do {
		u32 sff0 = readl(mmio_base + QS_HST_SFF);
		u32 sff1 = readl(mmio_base + QS_HST_SFF + 4);
		u8 sEVLD = (sff1 >> 30) & 0x01;	/* valid flag */
		sFFE  = sff1 >> 31;		/* empty flag */

		if (sEVLD) {
			u8 sDST = sff0 >> 16;	/* dev status */
			u8 sHST = sff1 & 0x3f;	/* host status */
			unsigned int port_no = (sff1 >> 8) & 0x03;
			struct ata_port *ap = host->ports[port_no];

			DPRINTK("SFF=%08x%08x: sCHAN=%u sHST=%d sDST=%02x\n",
					sff1, sff0, port_no, sHST, sDST);
			handled = 1;
			if (ap && !(ap->flags & ATA_FLAG_DISABLED)) {
				struct ata_queued_cmd *qc;
				struct qs_port_priv *pp = ap->private_data;
				if (!pp || pp->state != qs_state_pkt)
					continue;
				qc = ata_qc_from_tag(ap, ap->link.active_tag);
				if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING))) {
					switch (sHST) {
					case 0: /* successful CPB */
					case 3: /* device error */
						qs_enter_reg_mode(qc->ap);
						qs_do_or_die(qc, sDST);
						break;
					default:
						break;
					}
				}
			}
		}
	} while (!sFFE);
	return handled;
}

static inline unsigned int qs_intr_mmio(struct ata_host *host)
{
	unsigned int handled = 0, port_no;

	for (port_no = 0; port_no < host->n_ports; ++port_no) {
		struct ata_port *ap;
		ap = host->ports[port_no];
		if (ap &&
		    !(ap->flags & ATA_FLAG_DISABLED)) {
			struct ata_queued_cmd *qc;
			struct qs_port_priv *pp;
			qc = ata_qc_from_tag(ap, ap->link.active_tag);
			if (!qc || !(qc->flags & ATA_QCFLAG_ACTIVE)) {
				/*
				 * The qstor hardware generates spurious
				 * interrupts from time to time when switching
				 * in and out of packet mode.
				 * There's no obvious way to know if we're
				 * here now due to that, so just ack the irq
				 * and pretend we knew it was ours.. (ugh).
				 * This does not affect packet mode.
				 */
				ata_check_status(ap);
				handled = 1;
				continue;
			}
			pp = ap->private_data;
			if (!pp || pp->state != qs_state_mmio)
				continue;
			if (!(qc->tf.flags & ATA_TFLAG_POLLING))
				handled |= ata_host_intr(ap, qc);
		}
	}
	return handled;
}

static irqreturn_t qs_intr(int irq, void *dev_instance)
{
	struct ata_host *host = dev_instance;
	unsigned int handled = 0;
	unsigned long flags;

	VPRINTK("ENTER\n");

	spin_lock_irqsave(&host->lock, flags);
	handled  = qs_intr_pkt(host) | qs_intr_mmio(host);
	spin_unlock_irqrestore(&host->lock, flags);

	VPRINTK("EXIT\n");

	return IRQ_RETVAL(handled);
}

static void qs_ata_setup_port(struct ata_ioports *port, void __iomem *base)
{
	port->cmd_addr		=
	port->data_addr		= base + 0x400;
	port->error_addr	=
	port->feature_addr	= base + 0x408; /* hob_feature = 0x409 */
	port->nsect_addr	= base + 0x410; /* hob_nsect   = 0x411 */
	port->lbal_addr		= base + 0x418; /* hob_lbal    = 0x419 */
	port->lbam_addr		= base + 0x420; /* hob_lbam    = 0x421 */
	port->lbah_addr		= base + 0x428; /* hob_lbah    = 0x429 */
	port->device_addr	= base + 0x430;
	port->status_addr	=
	port->command_addr	= base + 0x438;
	port->altstatus_addr	=
	port->ctl_addr		= base + 0x440;
	port->scr_addr		= base + 0xc00;
}

static int qs_port_start(struct ata_port *ap)
{
	struct device *dev = ap->host->dev;
	struct qs_port_priv *pp;
	void __iomem *mmio_base = qs_mmio_base(ap->host);
	void __iomem *chan = mmio_base + (ap->port_no * 0x4000);
	u64 addr;
	int rc;

	rc = ata_port_start(ap);
	if (rc)
		return rc;
	pp = devm_kzalloc(dev, sizeof(*pp), GFP_KERNEL);
	if (!pp)
		return -ENOMEM;
	pp->pkt = dmam_alloc_coherent(dev, QS_PKT_BYTES, &pp->pkt_dma,
				      GFP_KERNEL);
	if (!pp->pkt)
		return -ENOMEM;
	memset(pp->pkt, 0, QS_PKT_BYTES);
	ap->private_data = pp;

	qs_enter_reg_mode(ap);
	addr = (u64)pp->pkt_dma;
	writel((u32) addr,        chan + QS_CCF_CPBA);
	writel((u32)(addr >> 32), chan + QS_CCF_CPBA + 4);
	return 0;
}

static void qs_host_stop(struct ata_host *host)
{
	void __iomem *mmio_base = qs_mmio_base(host);

	writeb(0, mmio_base + QS_HCT_CTRL); /* disable host interrupts */
	writeb(QS_CNFG3_GSRST, mmio_base + QS_HCF_CNFG3); /* global reset */
}

static void qs_host_init(struct ata_host *host, unsigned int chip_id)
{
	void __iomem *mmio_base = host->iomap[QS_MMIO_BAR];
	unsigned int port_no;

	writeb(0, mmio_base + QS_HCT_CTRL); /* disable host interrupts */
	writeb(QS_CNFG3_GSRST, mmio_base + QS_HCF_CNFG3); /* global reset */

	/* reset each channel in turn */
	for (port_no = 0; port_no < host->n_ports; ++port_no) {
		u8 __iomem *chan = mmio_base + (port_no * 0x4000);
		writeb(QS_CTR1_RDEV|QS_CTR1_RCHN, chan + QS_CCT_CTR1);
		writeb(QS_CTR0_REG, chan + QS_CCT_CTR0);
		readb(chan + QS_CCT_CTR0);        /* flush */
	}
	writeb(QS_SERD3_PHY_ENA, mmio_base + QS_HVS_SERD3); /* enable phy */

	for (port_no = 0; port_no < host->n_ports; ++port_no) {
		u8 __iomem *chan = mmio_base + (port_no * 0x4000);
		/* set FIFO depths to same settings as Windows driver */
		writew(32, chan + QS_CFC_HUFT);
		writew(32, chan + QS_CFC_HDFT);
		writew(10, chan + QS_CFC_DUFT);
		writew( 8, chan + QS_CFC_DDFT);
		/* set CPB size in bytes, as a power of two */
		writeb(QS_CPB_ORDER,    chan + QS_CCF_CSEP);
	}
	writeb(1, mmio_base + QS_HCT_CTRL); /* enable host interrupts */
}

/*
 * The QStor understands 64-bit buses, and uses 64-bit fields
 * for DMA pointers regardless of bus width.  We just have to
 * make sure our DMA masks are set appropriately for whatever
 * bridge lies between us and the QStor, and then the DMA mapping
 * code will ensure we only ever "see" appropriate buffer addresses.
 * If we're 32-bit limited somewhere, then our 64-bit fields will
 * just end up with zeros in the upper 32-bits, without any special
 * logic required outside of this routine (below).
 */
static int qs_set_dma_masks(struct pci_dev *pdev, void __iomem *mmio_base)
{
	u32 bus_info = readl(mmio_base + QS_HID_HPHY);
	int rc, have_64bit_bus = (bus_info & QS_HPHY_64BIT);

	if (have_64bit_bus &&
	    !pci_set_dma_mask(pdev, DMA_64BIT_MASK)) {
		rc = pci_set_consistent_dma_mask(pdev, DMA_64BIT_MASK);
		if (rc) {
			rc = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK);
			if (rc) {
				dev_printk(KERN_ERR, &pdev->dev,
					   "64-bit DMA enable failed\n");
				return rc;
			}
		}
	} else {
		rc = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
		if (rc) {
			dev_printk(KERN_ERR, &pdev->dev,
				"32-bit DMA enable failed\n");
			return rc;
		}
		rc = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK);
		if (rc) {
			dev_printk(KERN_ERR, &pdev->dev,
				"32-bit consistent DMA enable failed\n");
			return rc;
		}
	}
	return 0;
}

static int qs_ata_init_one(struct pci_dev *pdev,
				const struct pci_device_id *ent)
{
	static int printed_version;
	unsigned int board_idx = (unsigned int) ent->driver_data;
	const struct ata_port_info *ppi[] = { &qs_port_info[board_idx], NULL };
	struct ata_host *host;
	int rc, port_no;

	if (!printed_version++)
		dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");

	/* alloc host */
	host = ata_host_alloc_pinfo(&pdev->dev, ppi, QS_PORTS);
	if (!host)
		return -ENOMEM;

	/* acquire resources and fill host */
	rc = pcim_enable_device(pdev);
	if (rc)
		return rc;

	if ((pci_resource_flags(pdev, QS_MMIO_BAR) & IORESOURCE_MEM) == 0)
		return -ENODEV;

	rc = pcim_iomap_regions(pdev, 1 << QS_MMIO_BAR, DRV_NAME);
	if (rc)
		return rc;
	host->iomap = pcim_iomap_table(pdev);

	rc = qs_set_dma_masks(pdev, host->iomap[QS_MMIO_BAR]);
	if (rc)
		return rc;

	for (port_no = 0; port_no < host->n_ports; ++port_no) {
		struct ata_port *ap = host->ports[port_no];
		unsigned int offset = port_no * 0x4000;
		void __iomem *chan = host->iomap[QS_MMIO_BAR] + offset;

		qs_ata_setup_port(&ap->ioaddr, chan);

		ata_port_pbar_desc(ap, QS_MMIO_BAR, -1, "mmio");
		ata_port_pbar_desc(ap, QS_MMIO_BAR, offset, "port");
	}

	/* initialize adapter */
	qs_host_init(host, board_idx);

	pci_set_master(pdev);
	return ata_host_activate(host, pdev->irq, qs_intr, IRQF_SHARED,
				 &qs_ata_sht);
}

static int __init qs_ata_init(void)
{
	return pci_register_driver(&qs_ata_pci_driver);
}

static void __exit qs_ata_exit(void)
{
	pci_unregister_driver(&qs_ata_pci_driver);
}

MODULE_AUTHOR("Mark Lord");
MODULE_DESCRIPTION("Pacific Digital Corporation QStor SATA low-level driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, qs_ata_pci_tbl);
MODULE_VERSION(DRV_VERSION);

module_init(qs_ata_init);
module_exit(qs_ata_exit);