summaryrefslogtreecommitdiffstats
path: root/drivers/usb/host/whci/qset.c
blob: ab5a14fbfeeba0faf7a78e5e0a1870ee63e274a5 (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
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
/*
 * Wireless Host Controller (WHC) qset management.
 *
 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * 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.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <linux/kernel.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/uwb/umc.h>
#include <linux/usb.h>

#include "../../wusbcore/wusbhc.h"

#include "whcd.h"

struct whc_qset *qset_alloc(struct whc *whc, gfp_t mem_flags)
{
	struct whc_qset *qset;
	dma_addr_t dma;

	qset = dma_pool_alloc(whc->qset_pool, mem_flags, &dma);
	if (qset == NULL)
		return NULL;
	memset(qset, 0, sizeof(struct whc_qset));

	qset->qset_dma = dma;
	qset->whc = whc;

	INIT_LIST_HEAD(&qset->list_node);
	INIT_LIST_HEAD(&qset->stds);

	return qset;
}

/**
 * qset_fill_qh - fill the static endpoint state in a qset's QHead
 * @qset: the qset whose QH needs initializing with static endpoint
 *        state
 * @urb:  an urb for a transfer to this endpoint
 */
static void qset_fill_qh(struct whc *whc, struct whc_qset *qset, struct urb *urb)
{
	struct usb_device *usb_dev = urb->dev;
	struct wusb_dev *wusb_dev = usb_dev->wusb_dev;
	struct usb_wireless_ep_comp_descriptor *epcd;
	bool is_out;
	uint8_t phy_rate;

	is_out = usb_pipeout(urb->pipe);

	qset->max_packet = le16_to_cpu(urb->ep->desc.wMaxPacketSize);

	epcd = (struct usb_wireless_ep_comp_descriptor *)qset->ep->extra;
	if (epcd) {
		qset->max_seq = epcd->bMaxSequence;
		qset->max_burst = epcd->bMaxBurst;
	} else {
		qset->max_seq = 2;
		qset->max_burst = 1;
	}

	/*
	 * Initial PHY rate is 53.3 Mbit/s for control endpoints or
	 * the maximum supported by the device for other endpoints
	 * (unless limited by the user).
	 */
	if (usb_pipecontrol(urb->pipe))
		phy_rate = UWB_PHY_RATE_53;
	else {
		uint16_t phy_rates;

		phy_rates = le16_to_cpu(wusb_dev->wusb_cap_descr->wPHYRates);
		phy_rate = fls(phy_rates) - 1;
		if (phy_rate > whc->wusbhc.phy_rate)
			phy_rate = whc->wusbhc.phy_rate;
	}

	qset->qh.info1 = cpu_to_le32(
		QH_INFO1_EP(usb_pipeendpoint(urb->pipe))
		| (is_out ? QH_INFO1_DIR_OUT : QH_INFO1_DIR_IN)
		| usb_pipe_to_qh_type(urb->pipe)
		| QH_INFO1_DEV_INFO_IDX(wusb_port_no_to_idx(usb_dev->portnum))
		| QH_INFO1_MAX_PKT_LEN(qset->max_packet)
		);
	qset->qh.info2 = cpu_to_le32(
		QH_INFO2_BURST(qset->max_burst)
		| QH_INFO2_DBP(0)
		| QH_INFO2_MAX_COUNT(3)
		| QH_INFO2_MAX_RETRY(3)
		| QH_INFO2_MAX_SEQ(qset->max_seq - 1)
		);
	/* FIXME: where can we obtain these Tx parameters from?  Why
	 * doesn't the chip know what Tx power to use? It knows the Rx
	 * strength and can presumably guess the Tx power required
	 * from that? */
	qset->qh.info3 = cpu_to_le32(
		QH_INFO3_TX_RATE(phy_rate)
		| QH_INFO3_TX_PWR(0) /* 0 == max power */
		);

	qset->qh.cur_window = cpu_to_le32((1 << qset->max_burst) - 1);
}

/**
 * qset_clear - clear fields in a qset so it may be reinserted into a
 * schedule.
 *
 * The sequence number and current window are not cleared (see
 * qset_reset()).
 */
void qset_clear(struct whc *whc, struct whc_qset *qset)
{
	qset->td_start = qset->td_end = qset->ntds = 0;

	qset->qh.link = cpu_to_le32(QH_LINK_NTDS(8) | QH_LINK_T);
	qset->qh.status = qset->qh.status & QH_STATUS_SEQ_MASK;
	qset->qh.err_count = 0;
	qset->qh.scratch[0] = 0;
	qset->qh.scratch[1] = 0;
	qset->qh.scratch[2] = 0;

	memset(&qset->qh.overlay, 0, sizeof(qset->qh.overlay));

	init_completion(&qset->remove_complete);
}

/**
 * qset_reset - reset endpoint state in a qset.
 *
 * Clears the sequence number and current window.  This qset must not
 * be in the ASL or PZL.
 */
void qset_reset(struct whc *whc, struct whc_qset *qset)
{
	qset->reset = 0;

	qset->qh.status &= ~QH_STATUS_SEQ_MASK;
	qset->qh.cur_window = cpu_to_le32((1 << qset->max_burst) - 1);
}

/**
 * get_qset - get the qset for an async endpoint
 *
 * A new qset is created if one does not already exist.
 */
struct whc_qset *get_qset(struct whc *whc, struct urb *urb,
				 gfp_t mem_flags)
{
	struct whc_qset *qset;

	qset = urb->ep->hcpriv;
	if (qset == NULL) {
		qset = qset_alloc(whc, mem_flags);
		if (qset == NULL)
			return NULL;

		qset->ep = urb->ep;
		urb->ep->hcpriv = qset;
		qset_fill_qh(whc, qset, urb);
	}
	return qset;
}

void qset_remove_complete(struct whc *whc, struct whc_qset *qset)
{
	qset->remove = 0;
	list_del_init(&qset->list_node);
	complete(&qset->remove_complete);
}

/**
 * qset_add_qtds - add qTDs for an URB to a qset
 *
 * Returns true if the list (ASL/PZL) must be updated because (for a
 * WHCI 0.95 controller) an activated qTD was pointed to be iCur.
 */
enum whc_update qset_add_qtds(struct whc *whc, struct whc_qset *qset)
{
	struct whc_std *std;
	enum whc_update update = 0;

	list_for_each_entry(std, &qset->stds, list_node) {
		struct whc_qtd *qtd;
		uint32_t status;

		if (qset->ntds >= WHCI_QSET_TD_MAX
		    || (qset->pause_after_urb && std->urb != qset->pause_after_urb))
			break;

		if (std->qtd)
			continue; /* already has a qTD */

		qtd = std->qtd = &qset->qtd[qset->td_end];

		/* Fill in setup bytes for control transfers. */
		if (usb_pipecontrol(std->urb->pipe))
			memcpy(qtd->setup, std->urb->setup_packet, 8);

		status = QTD_STS_ACTIVE | QTD_STS_LEN(std->len);

		if (whc_std_last(std) && usb_pipeout(std->urb->pipe))
			status |= QTD_STS_LAST_PKT;

		/*
		 * For an IN transfer the iAlt field should be set so
		 * the h/w will automatically advance to the next
		 * transfer. However, if there are 8 or more TDs
		 * remaining in this transfer then iAlt cannot be set
		 * as it could point to somewhere in this transfer.
		 */
		if (std->ntds_remaining < WHCI_QSET_TD_MAX) {
			int ialt;
			ialt = (qset->td_end + std->ntds_remaining) % WHCI_QSET_TD_MAX;
			status |= QTD_STS_IALT(ialt);
		} else if (usb_pipein(std->urb->pipe))
			qset->pause_after_urb = std->urb;

		if (std->num_pointers)
			qtd->options = cpu_to_le32(QTD_OPT_IOC);
		else
			qtd->options = cpu_to_le32(QTD_OPT_IOC | QTD_OPT_SMALL);
		qtd->page_list_ptr = cpu_to_le64(std->dma_addr);

		qtd->status = cpu_to_le32(status);

		if (QH_STATUS_TO_ICUR(qset->qh.status) == qset->td_end)
			update = WHC_UPDATE_UPDATED;

		if (++qset->td_end >= WHCI_QSET_TD_MAX)
			qset->td_end = 0;
		qset->ntds++;
	}

	return update;
}

/**
 * qset_remove_qtd - remove the first qTD from a qset.
 *
 * The qTD might be still active (if it's part of a IN URB that
 * resulted in a short read) so ensure it's deactivated.
 */
static void qset_remove_qtd(struct whc *whc, struct whc_qset *qset)
{
	qset->qtd[qset->td_start].status = 0;

	if (++qset->td_start >= WHCI_QSET_TD_MAX)
		qset->td_start = 0;
	qset->ntds--;
}

static void qset_copy_bounce_to_sg(struct whc *whc, struct whc_std *std)
{
	struct scatterlist *sg;
	void *bounce;
	size_t remaining, offset;

	bounce = std->bounce_buf;
	remaining = std->len;

	sg = std->bounce_sg;
	offset = std->bounce_offset;

	while (remaining) {
		size_t len;

		len = min(sg->length - offset, remaining);
		memcpy(sg_virt(sg) + offset, bounce, len);

		bounce += len;
		remaining -= len;

		offset += len;
		if (offset >= sg->length) {
			sg = sg_next(sg);
			offset = 0;
		}
	}

}

/**
 * qset_free_std - remove an sTD and free it.
 * @whc: the WHCI host controller
 * @std: the sTD to remove and free.
 */
void qset_free_std(struct whc *whc, struct whc_std *std)
{
	list_del(&std->list_node);
	if (std->bounce_buf) {
		bool is_out = usb_pipeout(std->urb->pipe);
		dma_addr_t dma_addr;

		if (std->num_pointers)
			dma_addr = le64_to_cpu(std->pl_virt[0].buf_ptr);
		else
			dma_addr = std->dma_addr;

		dma_unmap_single(whc->wusbhc.dev, dma_addr,
				 std->len, is_out ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
		if (!is_out)
			qset_copy_bounce_to_sg(whc, std);
		kfree(std->bounce_buf);
	}
	if (std->pl_virt) {
		if (std->dma_addr)
			dma_unmap_single(whc->wusbhc.dev, std->dma_addr,
					 std->num_pointers * sizeof(struct whc_page_list_entry),
					 DMA_TO_DEVICE);
		kfree(std->pl_virt);
		std->pl_virt = NULL;
	}
	kfree(std);
}

/**
 * qset_remove_qtds - remove an URB's qTDs (and sTDs).
 */
static void qset_remove_qtds(struct whc *whc, struct whc_qset *qset,
			     struct urb *urb)
{
	struct whc_std *std, *t;

	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
		if (std->urb != urb)
			break;
		if (std->qtd != NULL)
			qset_remove_qtd(whc, qset);
		qset_free_std(whc, std);
	}
}

/**
 * qset_free_stds - free any remaining sTDs for an URB.
 */
static void qset_free_stds(struct whc_qset *qset, struct urb *urb)
{
	struct whc_std *std, *t;

	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
		if (std->urb == urb)
			qset_free_std(qset->whc, std);
	}
}

static int qset_fill_page_list(struct whc *whc, struct whc_std *std, gfp_t mem_flags)
{
	dma_addr_t dma_addr = std->dma_addr;
	dma_addr_t sp, ep;
	size_t pl_len;
	int p;

	/* Short buffers don't need a page list. */
	if (std->len <= WHCI_PAGE_SIZE) {
		std->num_pointers = 0;
		return 0;
	}

	sp = dma_addr & ~(WHCI_PAGE_SIZE-1);
	ep = dma_addr + std->len;
	std->num_pointers = DIV_ROUND_UP(ep - sp, WHCI_PAGE_SIZE);

	pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
	std->pl_virt = kmalloc(pl_len, mem_flags);
	if (std->pl_virt == NULL)
		return -ENOMEM;
	std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt, pl_len, DMA_TO_DEVICE);

	for (p = 0; p < std->num_pointers; p++) {
		std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
		dma_addr = (dma_addr + WHCI_PAGE_SIZE) & ~(WHCI_PAGE_SIZE-1);
	}

	return 0;
}

/**
 * urb_dequeue_work - executes asl/pzl update and gives back the urb to the system.
 */
static void urb_dequeue_work(struct work_struct *work)
{
	struct whc_urb *wurb = container_of(work, struct whc_urb, dequeue_work);
	struct whc_qset *qset = wurb->qset;
	struct whc *whc = qset->whc;
	unsigned long flags;

	if (wurb->is_async == true)
		asl_update(whc, WUSBCMD_ASYNC_UPDATED
			   | WUSBCMD_ASYNC_SYNCED_DB
			   | WUSBCMD_ASYNC_QSET_RM);
	else
		pzl_update(whc, WUSBCMD_PERIODIC_UPDATED
			   | WUSBCMD_PERIODIC_SYNCED_DB
			   | WUSBCMD_PERIODIC_QSET_RM);

	spin_lock_irqsave(&whc->lock, flags);
	qset_remove_urb(whc, qset, wurb->urb, wurb->status);
	spin_unlock_irqrestore(&whc->lock, flags);
}

static struct whc_std *qset_new_std(struct whc *whc, struct whc_qset *qset,
				    struct urb *urb, gfp_t mem_flags)
{
	struct whc_std *std;

	std = kzalloc(sizeof(struct whc_std), mem_flags);
	if (std == NULL)
		return NULL;

	std->urb = urb;
	std->qtd = NULL;

	INIT_LIST_HEAD(&std->list_node);
	list_add_tail(&std->list_node, &qset->stds);

	return std;
}

static int qset_add_urb_sg(struct whc *whc, struct whc_qset *qset, struct urb *urb,
			   gfp_t mem_flags)
{
	size_t remaining;
	struct scatterlist *sg;
	int i;
	int ntds = 0;
	struct whc_std *std = NULL;
	struct whc_page_list_entry *entry;
	dma_addr_t prev_end = 0;
	size_t pl_len;
	int p = 0;

	remaining = urb->transfer_buffer_length;

	for_each_sg(urb->sg, sg, urb->num_sgs, i) {
		dma_addr_t dma_addr;
		size_t dma_remaining;
		dma_addr_t sp, ep;
		int num_pointers;

		if (remaining == 0) {
			break;
		}

		dma_addr = sg_dma_address(sg);
		dma_remaining = min_t(size_t, sg_dma_len(sg), remaining);

		while (dma_remaining) {
			size_t dma_len;

			/*
			 * We can use the previous std (if it exists) provided that:
			 * - the previous one ended on a page boundary.
			 * - the current one begins on a page boundary.
			 * - the previous one isn't full.
			 *
			 * If a new std is needed but the previous one
			 * was not a whole number of packets then this
			 * sg list cannot be mapped onto multiple
			 * qTDs.  Return an error and let the caller
			 * sort it out.
			 */
			if (!std
			    || (prev_end & (WHCI_PAGE_SIZE-1))
			    || (dma_addr & (WHCI_PAGE_SIZE-1))
			    || std->len + WHCI_PAGE_SIZE > QTD_MAX_XFER_SIZE) {
				if (std->len % qset->max_packet != 0)
					return -EINVAL;
				std = qset_new_std(whc, qset, urb, mem_flags);
				if (std == NULL) {
					return -ENOMEM;
				}
				ntds++;
				p = 0;
			}

			dma_len = dma_remaining;

			/*
			 * If the remainder of this element doesn't
			 * fit in a single qTD, limit the qTD to a
			 * whole number of packets.  This allows the
			 * remainder to go into the next qTD.
			 */
			if (std->len + dma_len > QTD_MAX_XFER_SIZE) {
				dma_len = (QTD_MAX_XFER_SIZE / qset->max_packet)
					* qset->max_packet - std->len;
			}

			std->len += dma_len;
			std->ntds_remaining = -1; /* filled in later */

			sp = dma_addr & ~(WHCI_PAGE_SIZE-1);
			ep = dma_addr + dma_len;
			num_pointers = DIV_ROUND_UP(ep - sp, WHCI_PAGE_SIZE);
			std->num_pointers += num_pointers;

			pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);

			std->pl_virt = krealloc(std->pl_virt, pl_len, mem_flags);
			if (std->pl_virt == NULL) {
				return -ENOMEM;
			}

			for (;p < std->num_pointers; p++, entry++) {
				std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
				dma_addr = (dma_addr + WHCI_PAGE_SIZE) & ~(WHCI_PAGE_SIZE-1);
			}

			prev_end = dma_addr = ep;
			dma_remaining -= dma_len;
			remaining -= dma_len;
		}
	}

	/* Now the number of stds is know, go back and fill in
	   std->ntds_remaining. */
	list_for_each_entry(std, &qset->stds, list_node) {
		if (std->ntds_remaining == -1) {
			pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
			std->ntds_remaining = ntds--;
			std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt,
						       pl_len, DMA_TO_DEVICE);
		}
	}
	return 0;
}

/**
 * qset_add_urb_sg_linearize - add an urb with sg list, copying the data
 *
 * If the URB contains an sg list whose elements cannot be directly
 * mapped to qTDs then the data must be transferred via bounce
 * buffers.
 */
static int qset_add_urb_sg_linearize(struct whc *whc, struct whc_qset *qset,
				     struct urb *urb, gfp_t mem_flags)
{
	bool is_out = usb_pipeout(urb->pipe);
	size_t max_std_len;
	size_t remaining;
	int ntds = 0;
	struct whc_std *std = NULL;
	void *bounce = NULL;
	struct scatterlist *sg;
	int i;

	/* limit maximum bounce buffer to 16 * 3.5 KiB ~= 28 k */
	max_std_len = qset->max_burst * qset->max_packet;

	remaining = urb->transfer_buffer_length;

	for_each_sg(urb->sg, sg, urb->num_sgs, i) {
		size_t len;
		size_t sg_remaining;
		void *orig;

		if (remaining == 0) {
			break;
		}

		sg_remaining = min_t(size_t, remaining, sg->length);
		orig = sg_virt(sg);

		while (sg_remaining) {
			if (!std || std->len == max_std_len) {
				std = qset_new_std(whc, qset, urb, mem_flags);
				if (std == NULL)
					return -ENOMEM;
				std->bounce_buf = kmalloc(max_std_len, mem_flags);
				if (std->bounce_buf == NULL)
					return -ENOMEM;
				std->bounce_sg = sg;
				std->bounce_offset = orig - sg_virt(sg);
				bounce = std->bounce_buf;
				ntds++;
			}

			len = min(sg_remaining, max_std_len - std->len);

			if (is_out)
				memcpy(bounce, orig, len);

			std->len += len;
			std->ntds_remaining = -1; /* filled in later */

			bounce += len;
			orig += len;
			sg_remaining -= len;
			remaining -= len;
		}
	}

	/*
	 * For each of the new sTDs, map the bounce buffers, create
	 * page lists (if necessary), and fill in std->ntds_remaining.
	 */
	list_for_each_entry(std, &qset->stds, list_node) {
		if (std->ntds_remaining != -1)
			continue;

		std->dma_addr = dma_map_single(&whc->umc->dev, std->bounce_buf, std->len,
					       is_out ? DMA_TO_DEVICE : DMA_FROM_DEVICE);

		if (qset_fill_page_list(whc, std, mem_flags) < 0)
			return -ENOMEM;

		std->ntds_remaining = ntds--;
	}

	return 0;
}

/**
 * qset_add_urb - add an urb to the qset's queue.
 *
 * The URB is chopped into sTDs, one for each qTD that will required.
 * At least one qTD (and sTD) is required even if the transfer has no
 * data (e.g., for some control transfers).
 */
int qset_add_urb(struct whc *whc, struct whc_qset *qset, struct urb *urb,
	gfp_t mem_flags)
{
	struct whc_urb *wurb;
	int remaining = urb->transfer_buffer_length;
	u64 transfer_dma = urb->transfer_dma;
	int ntds_remaining;
	int ret;

	wurb = kzalloc(sizeof(struct whc_urb), mem_flags);
	if (wurb == NULL)
		goto err_no_mem;
	urb->hcpriv = wurb;
	wurb->qset = qset;
	wurb->urb = urb;
	INIT_WORK(&wurb->dequeue_work, urb_dequeue_work);

	if (urb->num_sgs) {
		ret = qset_add_urb_sg(whc, qset, urb, mem_flags);
		if (ret == -EINVAL) {
			qset_free_stds(qset, urb);
			ret = qset_add_urb_sg_linearize(whc, qset, urb, mem_flags);
		}
		if (ret < 0)
			goto err_no_mem;
		return 0;
	}

	ntds_remaining = DIV_ROUND_UP(remaining, QTD_MAX_XFER_SIZE);
	if (ntds_remaining == 0)
		ntds_remaining = 1;

	while (ntds_remaining) {
		struct whc_std *std;
		size_t std_len;

		std_len = remaining;
		if (std_len > QTD_MAX_XFER_SIZE)
			std_len = QTD_MAX_XFER_SIZE;

		std = qset_new_std(whc, qset, urb, mem_flags);
		if (std == NULL)
			goto err_no_mem;

		std->dma_addr = transfer_dma;
		std->len = std_len;
		std->ntds_remaining = ntds_remaining;

		if (qset_fill_page_list(whc, std, mem_flags) < 0)
			goto err_no_mem;

		ntds_remaining--;
		remaining -= std_len;
		transfer_dma += std_len;
	}

	return 0;

err_no_mem:
	qset_free_stds(qset, urb);
	return -ENOMEM;
}

/**
 * qset_remove_urb - remove an URB from the urb queue.
 *
 * The URB is returned to the USB subsystem.
 */
void qset_remove_urb(struct whc *whc, struct whc_qset *qset,
			    struct urb *urb, int status)
{
	struct wusbhc *wusbhc = &whc->wusbhc;
	struct whc_urb *wurb = urb->hcpriv;

	usb_hcd_unlink_urb_from_ep(&wusbhc->usb_hcd, urb);
	/* Drop the lock as urb->complete() may enqueue another urb. */
	spin_unlock(&whc->lock);
	wusbhc_giveback_urb(wusbhc, urb, status);
	spin_lock(&whc->lock);

	kfree(wurb);
}

/**
 * get_urb_status_from_qtd - get the completed urb status from qTD status
 * @urb:    completed urb
 * @status: qTD status
 */
static int get_urb_status_from_qtd(struct urb *urb, u32 status)
{
	if (status & QTD_STS_HALTED) {
		if (status & QTD_STS_DBE)
			return usb_pipein(urb->pipe) ? -ENOSR : -ECOMM;
		else if (status & QTD_STS_BABBLE)
			return -EOVERFLOW;
		else if (status & QTD_STS_RCE)
			return -ETIME;
		return -EPIPE;
	}
	if (usb_pipein(urb->pipe)
	    && (urb->transfer_flags & URB_SHORT_NOT_OK)
	    && urb->actual_length < urb->transfer_buffer_length)
		return -EREMOTEIO;
	return 0;
}

/**
 * process_inactive_qtd - process an inactive (but not halted) qTD.
 *
 * Update the urb with the transfer bytes from the qTD, if the urb is
 * completely transfered or (in the case of an IN only) the LPF is
 * set, then the transfer is complete and the urb should be returned
 * to the system.
 */
void process_inactive_qtd(struct whc *whc, struct whc_qset *qset,
				 struct whc_qtd *qtd)
{
	struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
	struct urb *urb = std->urb;
	uint32_t status;
	bool complete;

	status = le32_to_cpu(qtd->status);

	urb->actual_length += std->len - QTD_STS_TO_LEN(status);

	if (usb_pipein(urb->pipe) && (status & QTD_STS_LAST_PKT))
		complete = true;
	else
		complete = whc_std_last(std);

	qset_remove_qtd(whc, qset);
	qset_free_std(whc, std);

	/*
	 * Transfers for this URB are complete?  Then return it to the
	 * USB subsystem.
	 */
	if (complete) {
		qset_remove_qtds(whc, qset, urb);
		qset_remove_urb(whc, qset, urb, get_urb_status_from_qtd(urb, status));

		/*
		 * If iAlt isn't valid then the hardware didn't
		 * advance iCur. Adjust the start and end pointers to
		 * match iCur.
		 */
		if (!(status & QTD_STS_IALT_VALID))
			qset->td_start = qset->td_end
				= QH_STATUS_TO_ICUR(le16_to_cpu(qset->qh.status));
		qset->pause_after_urb = NULL;
	}
}

/**
 * process_halted_qtd - process a qset with a halted qtd
 *
 * Remove all the qTDs for the failed URB and return the failed URB to
 * the USB subsystem.  Then remove all other qTDs so the qset can be
 * removed.
 *
 * FIXME: this is the point where rate adaptation can be done.  If a
 * transfer failed because it exceeded the maximum number of retries
 * then it could be reactivated with a slower rate without having to
 * remove the qset.
 */
void process_halted_qtd(struct whc *whc, struct whc_qset *qset,
			       struct whc_qtd *qtd)
{
	struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
	struct urb *urb = std->urb;
	int urb_status;

	urb_status = get_urb_status_from_qtd(urb, le32_to_cpu(qtd->status));

	qset_remove_qtds(whc, qset, urb);
	qset_remove_urb(whc, qset, urb, urb_status);

	list_for_each_entry(std, &qset->stds, list_node) {
		if (qset->ntds == 0)
			break;
		qset_remove_qtd(whc, qset);
		std->qtd = NULL;
	}

	qset->remove = 1;
}

void qset_free(struct whc *whc, struct whc_qset *qset)
{
	dma_pool_free(whc->qset_pool, qset, qset->qset_dma);
}

/**
 * qset_delete - wait for a qset to be unused, then free it.
 */
void qset_delete(struct whc *whc, struct whc_qset *qset)
{
	wait_for_completion(&qset->remove_complete);
	qset_free(whc, qset);
}
OpenPOWER on IntegriCloud