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  1/*
  2 * Wireless Host Controller (WHC) qset management.
  3 *
  4 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License version
  8 * 2 as published by the Free Software Foundation.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU General Public License
 16 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 17 */
 18#include <linux/kernel.h>
 19#include <linux/dma-mapping.h>
 20#include <linux/slab.h>
 21#include <linux/uwb/umc.h>
 22#include <linux/usb.h>
 23
 24#include "../../wusbcore/wusbhc.h"
 25
 26#include "whcd.h"
 27
 28struct whc_qset *qset_alloc(struct whc *whc, gfp_t mem_flags)
 29{
 30	struct whc_qset *qset;
 31	dma_addr_t dma;
 32
 33	qset = dma_pool_zalloc(whc->qset_pool, mem_flags, &dma);
 34	if (qset == NULL)
 35		return NULL;
 36
 37	qset->qset_dma = dma;
 38	qset->whc = whc;
 39
 40	INIT_LIST_HEAD(&qset->list_node);
 41	INIT_LIST_HEAD(&qset->stds);
 42
 43	return qset;
 44}
 45
 46/**
 47 * qset_fill_qh - fill the static endpoint state in a qset's QHead
 48 * @qset: the qset whose QH needs initializing with static endpoint
 49 *        state
 50 * @urb:  an urb for a transfer to this endpoint
 51 */
 52static void qset_fill_qh(struct whc *whc, struct whc_qset *qset, struct urb *urb)
 53{
 54	struct usb_device *usb_dev = urb->dev;
 55	struct wusb_dev *wusb_dev = usb_dev->wusb_dev;
 56	struct usb_wireless_ep_comp_descriptor *epcd;
 57	bool is_out;
 58	uint8_t phy_rate;
 59
 60	is_out = usb_pipeout(urb->pipe);
 61
 62	qset->max_packet = le16_to_cpu(urb->ep->desc.wMaxPacketSize);
 63
 64	epcd = (struct usb_wireless_ep_comp_descriptor *)qset->ep->extra;
 65	if (epcd) {
 66		qset->max_seq = epcd->bMaxSequence;
 67		qset->max_burst = epcd->bMaxBurst;
 68	} else {
 69		qset->max_seq = 2;
 70		qset->max_burst = 1;
 71	}
 72
 73	/*
 74	 * Initial PHY rate is 53.3 Mbit/s for control endpoints or
 75	 * the maximum supported by the device for other endpoints
 76	 * (unless limited by the user).
 77	 */
 78	if (usb_pipecontrol(urb->pipe))
 79		phy_rate = UWB_PHY_RATE_53;
 80	else {
 81		uint16_t phy_rates;
 82
 83		phy_rates = le16_to_cpu(wusb_dev->wusb_cap_descr->wPHYRates);
 84		phy_rate = fls(phy_rates) - 1;
 85		if (phy_rate > whc->wusbhc.phy_rate)
 86			phy_rate = whc->wusbhc.phy_rate;
 87	}
 88
 89	qset->qh.info1 = cpu_to_le32(
 90		QH_INFO1_EP(usb_pipeendpoint(urb->pipe))
 91		| (is_out ? QH_INFO1_DIR_OUT : QH_INFO1_DIR_IN)
 92		| usb_pipe_to_qh_type(urb->pipe)
 93		| QH_INFO1_DEV_INFO_IDX(wusb_port_no_to_idx(usb_dev->portnum))
 94		| QH_INFO1_MAX_PKT_LEN(qset->max_packet)
 95		);
 96	qset->qh.info2 = cpu_to_le32(
 97		QH_INFO2_BURST(qset->max_burst)
 98		| QH_INFO2_DBP(0)
 99		| QH_INFO2_MAX_COUNT(3)
100		| QH_INFO2_MAX_RETRY(3)
101		| QH_INFO2_MAX_SEQ(qset->max_seq - 1)
102		);
103	/* FIXME: where can we obtain these Tx parameters from?  Why
104	 * doesn't the chip know what Tx power to use? It knows the Rx
105	 * strength and can presumably guess the Tx power required
106	 * from that? */
107	qset->qh.info3 = cpu_to_le32(
108		QH_INFO3_TX_RATE(phy_rate)
109		| QH_INFO3_TX_PWR(0) /* 0 == max power */
110		);
111
112	qset->qh.cur_window = cpu_to_le32((1 << qset->max_burst) - 1);
113}
114
115/**
116 * qset_clear - clear fields in a qset so it may be reinserted into a
117 * schedule.
118 *
119 * The sequence number and current window are not cleared (see
120 * qset_reset()).
121 */
122void qset_clear(struct whc *whc, struct whc_qset *qset)
123{
124	qset->td_start = qset->td_end = qset->ntds = 0;
125
126	qset->qh.link = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
127	qset->qh.status = qset->qh.status & QH_STATUS_SEQ_MASK;
128	qset->qh.err_count = 0;
129	qset->qh.scratch[0] = 0;
130	qset->qh.scratch[1] = 0;
131	qset->qh.scratch[2] = 0;
132
133	memset(&qset->qh.overlay, 0, sizeof(qset->qh.overlay));
134
135	init_completion(&qset->remove_complete);
136}
137
138/**
139 * qset_reset - reset endpoint state in a qset.
140 *
141 * Clears the sequence number and current window.  This qset must not
142 * be in the ASL or PZL.
143 */
144void qset_reset(struct whc *whc, struct whc_qset *qset)
145{
146	qset->reset = 0;
147
148	qset->qh.status &= ~QH_STATUS_SEQ_MASK;
149	qset->qh.cur_window = cpu_to_le32((1 << qset->max_burst) - 1);
150}
151
152/**
153 * get_qset - get the qset for an async endpoint
154 *
155 * A new qset is created if one does not already exist.
156 */
157struct whc_qset *get_qset(struct whc *whc, struct urb *urb,
158				 gfp_t mem_flags)
159{
160	struct whc_qset *qset;
161
162	qset = urb->ep->hcpriv;
163	if (qset == NULL) {
164		qset = qset_alloc(whc, mem_flags);
165		if (qset == NULL)
166			return NULL;
167
168		qset->ep = urb->ep;
169		urb->ep->hcpriv = qset;
170		qset_fill_qh(whc, qset, urb);
171	}
172	return qset;
173}
174
175void qset_remove_complete(struct whc *whc, struct whc_qset *qset)
176{
177	qset->remove = 0;
178	list_del_init(&qset->list_node);
179	complete(&qset->remove_complete);
180}
181
182/**
183 * qset_add_qtds - add qTDs for an URB to a qset
184 *
185 * Returns true if the list (ASL/PZL) must be updated because (for a
186 * WHCI 0.95 controller) an activated qTD was pointed to be iCur.
187 */
188enum whc_update qset_add_qtds(struct whc *whc, struct whc_qset *qset)
189{
190	struct whc_std *std;
191	enum whc_update update = 0;
192
193	list_for_each_entry(std, &qset->stds, list_node) {
194		struct whc_qtd *qtd;
195		uint32_t status;
196
197		if (qset->ntds >= WHCI_QSET_TD_MAX
198		    || (qset->pause_after_urb && std->urb != qset->pause_after_urb))
199			break;
200
201		if (std->qtd)
202			continue; /* already has a qTD */
203
204		qtd = std->qtd = &qset->qtd[qset->td_end];
205
206		/* Fill in setup bytes for control transfers. */
207		if (usb_pipecontrol(std->urb->pipe))
208			memcpy(qtd->setup, std->urb->setup_packet, 8);
209
210		status = QTD_STS_ACTIVE | QTD_STS_LEN(std->len);
211
212		if (whc_std_last(std) && usb_pipeout(std->urb->pipe))
213			status |= QTD_STS_LAST_PKT;
214
215		/*
216		 * For an IN transfer the iAlt field should be set so
217		 * the h/w will automatically advance to the next
218		 * transfer. However, if there are 8 or more TDs
219		 * remaining in this transfer then iAlt cannot be set
220		 * as it could point to somewhere in this transfer.
221		 */
222		if (std->ntds_remaining < WHCI_QSET_TD_MAX) {
223			int ialt;
224			ialt = (qset->td_end + std->ntds_remaining) % WHCI_QSET_TD_MAX;
225			status |= QTD_STS_IALT(ialt);
226		} else if (usb_pipein(std->urb->pipe))
227			qset->pause_after_urb = std->urb;
228
229		if (std->num_pointers)
230			qtd->options = cpu_to_le32(QTD_OPT_IOC);
231		else
232			qtd->options = cpu_to_le32(QTD_OPT_IOC | QTD_OPT_SMALL);
233		qtd->page_list_ptr = cpu_to_le64(std->dma_addr);
234
235		qtd->status = cpu_to_le32(status);
236
237		if (QH_STATUS_TO_ICUR(qset->qh.status) == qset->td_end)
238			update = WHC_UPDATE_UPDATED;
239
240		if (++qset->td_end >= WHCI_QSET_TD_MAX)
241			qset->td_end = 0;
242		qset->ntds++;
243	}
244
245	return update;
246}
247
248/**
249 * qset_remove_qtd - remove the first qTD from a qset.
250 *
251 * The qTD might be still active (if it's part of a IN URB that
252 * resulted in a short read) so ensure it's deactivated.
253 */
254static void qset_remove_qtd(struct whc *whc, struct whc_qset *qset)
255{
256	qset->qtd[qset->td_start].status = 0;
257
258	if (++qset->td_start >= WHCI_QSET_TD_MAX)
259		qset->td_start = 0;
260	qset->ntds--;
261}
262
263static void qset_copy_bounce_to_sg(struct whc *whc, struct whc_std *std)
264{
265	struct scatterlist *sg;
266	void *bounce;
267	size_t remaining, offset;
268
269	bounce = std->bounce_buf;
270	remaining = std->len;
271
272	sg = std->bounce_sg;
273	offset = std->bounce_offset;
274
275	while (remaining) {
276		size_t len;
277
278		len = min(sg->length - offset, remaining);
279		memcpy(sg_virt(sg) + offset, bounce, len);
280
281		bounce += len;
282		remaining -= len;
283
284		offset += len;
285		if (offset >= sg->length) {
286			sg = sg_next(sg);
287			offset = 0;
288		}
289	}
290
291}
292
293/**
294 * qset_free_std - remove an sTD and free it.
295 * @whc: the WHCI host controller
296 * @std: the sTD to remove and free.
297 */
298void qset_free_std(struct whc *whc, struct whc_std *std)
299{
300	list_del(&std->list_node);
301	if (std->bounce_buf) {
302		bool is_out = usb_pipeout(std->urb->pipe);
303		dma_addr_t dma_addr;
304
305		if (std->num_pointers)
306			dma_addr = le64_to_cpu(std->pl_virt[0].buf_ptr);
307		else
308			dma_addr = std->dma_addr;
309
310		dma_unmap_single(whc->wusbhc.dev, dma_addr,
311				 std->len, is_out ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
312		if (!is_out)
313			qset_copy_bounce_to_sg(whc, std);
314		kfree(std->bounce_buf);
315	}
316	if (std->pl_virt) {
317		if (std->dma_addr)
318			dma_unmap_single(whc->wusbhc.dev, std->dma_addr,
319					 std->num_pointers * sizeof(struct whc_page_list_entry),
320					 DMA_TO_DEVICE);
321		kfree(std->pl_virt);
322		std->pl_virt = NULL;
323	}
324	kfree(std);
325}
326
327/**
328 * qset_remove_qtds - remove an URB's qTDs (and sTDs).
329 */
330static void qset_remove_qtds(struct whc *whc, struct whc_qset *qset,
331			     struct urb *urb)
332{
333	struct whc_std *std, *t;
334
335	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
336		if (std->urb != urb)
337			break;
338		if (std->qtd != NULL)
339			qset_remove_qtd(whc, qset);
340		qset_free_std(whc, std);
341	}
342}
343
344/**
345 * qset_free_stds - free any remaining sTDs for an URB.
346 */
347static void qset_free_stds(struct whc_qset *qset, struct urb *urb)
348{
349	struct whc_std *std, *t;
350
351	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
352		if (std->urb == urb)
353			qset_free_std(qset->whc, std);
354	}
355}
356
357static int qset_fill_page_list(struct whc *whc, struct whc_std *std, gfp_t mem_flags)
358{
359	dma_addr_t dma_addr = std->dma_addr;
360	dma_addr_t sp, ep;
361	size_t pl_len;
362	int p;
363
364	/* Short buffers don't need a page list. */
365	if (std->len <= WHCI_PAGE_SIZE) {
366		std->num_pointers = 0;
367		return 0;
368	}
369
370	sp = dma_addr & ~(WHCI_PAGE_SIZE-1);
371	ep = dma_addr + std->len;
372	std->num_pointers = DIV_ROUND_UP(ep - sp, WHCI_PAGE_SIZE);
373
374	pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
375	std->pl_virt = kmalloc(pl_len, mem_flags);
376	if (std->pl_virt == NULL)
377		return -ENOMEM;
378	std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt, pl_len, DMA_TO_DEVICE);
379	if (dma_mapping_error(whc->wusbhc.dev, std->dma_addr)) {
380		kfree(std->pl_virt);
381		return -EFAULT;
382	}
383
384	for (p = 0; p < std->num_pointers; p++) {
385		std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
386		dma_addr = (dma_addr + WHCI_PAGE_SIZE) & ~(WHCI_PAGE_SIZE-1);
387	}
388
389	return 0;
390}
391
392/**
393 * urb_dequeue_work - executes asl/pzl update and gives back the urb to the system.
394 */
395static void urb_dequeue_work(struct work_struct *work)
396{
397	struct whc_urb *wurb = container_of(work, struct whc_urb, dequeue_work);
398	struct whc_qset *qset = wurb->qset;
399	struct whc *whc = qset->whc;
400	unsigned long flags;
401
402	if (wurb->is_async)
403		asl_update(whc, WUSBCMD_ASYNC_UPDATED
404			   | WUSBCMD_ASYNC_SYNCED_DB
405			   | WUSBCMD_ASYNC_QSET_RM);
406	else
407		pzl_update(whc, WUSBCMD_PERIODIC_UPDATED
408			   | WUSBCMD_PERIODIC_SYNCED_DB
409			   | WUSBCMD_PERIODIC_QSET_RM);
410
411	spin_lock_irqsave(&whc->lock, flags);
412	qset_remove_urb(whc, qset, wurb->urb, wurb->status);
413	spin_unlock_irqrestore(&whc->lock, flags);
414}
415
416static struct whc_std *qset_new_std(struct whc *whc, struct whc_qset *qset,
417				    struct urb *urb, gfp_t mem_flags)
418{
419	struct whc_std *std;
420
421	std = kzalloc(sizeof(struct whc_std), mem_flags);
422	if (std == NULL)
423		return NULL;
424
425	std->urb = urb;
426	std->qtd = NULL;
427
428	INIT_LIST_HEAD(&std->list_node);
429	list_add_tail(&std->list_node, &qset->stds);
430
431	return std;
432}
433
434static int qset_add_urb_sg(struct whc *whc, struct whc_qset *qset, struct urb *urb,
435			   gfp_t mem_flags)
436{
437	size_t remaining;
438	struct scatterlist *sg;
439	int i;
440	int ntds = 0;
441	struct whc_std *std = NULL;
442	struct whc_page_list_entry *new_pl_virt;
443	dma_addr_t prev_end = 0;
444	size_t pl_len;
445	int p = 0;
446
447	remaining = urb->transfer_buffer_length;
448
449	for_each_sg(urb->sg, sg, urb->num_mapped_sgs, i) {
450		dma_addr_t dma_addr;
451		size_t dma_remaining;
452		dma_addr_t sp, ep;
453		int num_pointers;
454
455		if (remaining == 0) {
456			break;
457		}
458
459		dma_addr = sg_dma_address(sg);
460		dma_remaining = min_t(size_t, sg_dma_len(sg), remaining);
461
462		while (dma_remaining) {
463			size_t dma_len;
464
465			/*
466			 * We can use the previous std (if it exists) provided that:
467			 * - the previous one ended on a page boundary.
468			 * - the current one begins on a page boundary.
469			 * - the previous one isn't full.
470			 *
471			 * If a new std is needed but the previous one
472			 * was not a whole number of packets then this
473			 * sg list cannot be mapped onto multiple
474			 * qTDs.  Return an error and let the caller
475			 * sort it out.
476			 */
477			if (!std
478			    || (prev_end & (WHCI_PAGE_SIZE-1))
479			    || (dma_addr & (WHCI_PAGE_SIZE-1))
480			    || std->len + WHCI_PAGE_SIZE > QTD_MAX_XFER_SIZE) {
481				if (std && std->len % qset->max_packet != 0)
482					return -EINVAL;
483				std = qset_new_std(whc, qset, urb, mem_flags);
484				if (std == NULL) {
485					return -ENOMEM;
486				}
487				ntds++;
488				p = 0;
489			}
490
491			dma_len = dma_remaining;
492
493			/*
494			 * If the remainder of this element doesn't
495			 * fit in a single qTD, limit the qTD to a
496			 * whole number of packets.  This allows the
497			 * remainder to go into the next qTD.
498			 */
499			if (std->len + dma_len > QTD_MAX_XFER_SIZE) {
500				dma_len = (QTD_MAX_XFER_SIZE / qset->max_packet)
501					* qset->max_packet - std->len;
502			}
503
504			std->len += dma_len;
505			std->ntds_remaining = -1; /* filled in later */
506
507			sp = dma_addr & ~(WHCI_PAGE_SIZE-1);
508			ep = dma_addr + dma_len;
509			num_pointers = DIV_ROUND_UP(ep - sp, WHCI_PAGE_SIZE);
510			std->num_pointers += num_pointers;
511
512			pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
513
514			new_pl_virt = krealloc(std->pl_virt, pl_len, mem_flags);
515			if (new_pl_virt == NULL) {
516				kfree(std->pl_virt);
517				std->pl_virt = NULL;
518				return -ENOMEM;
519			}
520			std->pl_virt = new_pl_virt;
521
522			for (;p < std->num_pointers; p++) {
523				std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
524				dma_addr = (dma_addr + WHCI_PAGE_SIZE) & ~(WHCI_PAGE_SIZE-1);
525			}
526
527			prev_end = dma_addr = ep;
528			dma_remaining -= dma_len;
529			remaining -= dma_len;
530		}
531	}
532
533	/* Now the number of stds is know, go back and fill in
534	   std->ntds_remaining. */
535	list_for_each_entry(std, &qset->stds, list_node) {
536		if (std->ntds_remaining == -1) {
537			pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
538			std->ntds_remaining = ntds--;
539			std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt,
540						       pl_len, DMA_TO_DEVICE);
541		}
542	}
543	return 0;
544}
545
546/**
547 * qset_add_urb_sg_linearize - add an urb with sg list, copying the data
548 *
549 * If the URB contains an sg list whose elements cannot be directly
550 * mapped to qTDs then the data must be transferred via bounce
551 * buffers.
552 */
553static int qset_add_urb_sg_linearize(struct whc *whc, struct whc_qset *qset,
554				     struct urb *urb, gfp_t mem_flags)
555{
556	bool is_out = usb_pipeout(urb->pipe);
557	size_t max_std_len;
558	size_t remaining;
559	int ntds = 0;
560	struct whc_std *std = NULL;
561	void *bounce = NULL;
562	struct scatterlist *sg;
563	int i;
564
565	/* limit maximum bounce buffer to 16 * 3.5 KiB ~= 28 k */
566	max_std_len = qset->max_burst * qset->max_packet;
567
568	remaining = urb->transfer_buffer_length;
569
570	for_each_sg(urb->sg, sg, urb->num_mapped_sgs, i) {
571		size_t len;
572		size_t sg_remaining;
573		void *orig;
574
575		if (remaining == 0) {
576			break;
577		}
578
579		sg_remaining = min_t(size_t, remaining, sg->length);
580		orig = sg_virt(sg);
581
582		while (sg_remaining) {
583			if (!std || std->len == max_std_len) {
584				std = qset_new_std(whc, qset, urb, mem_flags);
585				if (std == NULL)
586					return -ENOMEM;
587				std->bounce_buf = kmalloc(max_std_len, mem_flags);
588				if (std->bounce_buf == NULL)
589					return -ENOMEM;
590				std->bounce_sg = sg;
591				std->bounce_offset = orig - sg_virt(sg);
592				bounce = std->bounce_buf;
593				ntds++;
594			}
595
596			len = min(sg_remaining, max_std_len - std->len);
597
598			if (is_out)
599				memcpy(bounce, orig, len);
600
601			std->len += len;
602			std->ntds_remaining = -1; /* filled in later */
603
604			bounce += len;
605			orig += len;
606			sg_remaining -= len;
607			remaining -= len;
608		}
609	}
610
611	/*
612	 * For each of the new sTDs, map the bounce buffers, create
613	 * page lists (if necessary), and fill in std->ntds_remaining.
614	 */
615	list_for_each_entry(std, &qset->stds, list_node) {
616		if (std->ntds_remaining != -1)
617			continue;
618
619		std->dma_addr = dma_map_single(&whc->umc->dev, std->bounce_buf, std->len,
620					       is_out ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
621
622		if (qset_fill_page_list(whc, std, mem_flags) < 0)
623			return -ENOMEM;
624
625		std->ntds_remaining = ntds--;
626	}
627
628	return 0;
629}
630
631/**
632 * qset_add_urb - add an urb to the qset's queue.
633 *
634 * The URB is chopped into sTDs, one for each qTD that will required.
635 * At least one qTD (and sTD) is required even if the transfer has no
636 * data (e.g., for some control transfers).
637 */
638int qset_add_urb(struct whc *whc, struct whc_qset *qset, struct urb *urb,
639	gfp_t mem_flags)
640{
641	struct whc_urb *wurb;
642	int remaining = urb->transfer_buffer_length;
643	u64 transfer_dma = urb->transfer_dma;
644	int ntds_remaining;
645	int ret;
646
647	wurb = kzalloc(sizeof(struct whc_urb), mem_flags);
648	if (wurb == NULL)
649		goto err_no_mem;
650	urb->hcpriv = wurb;
651	wurb->qset = qset;
652	wurb->urb = urb;
653	INIT_WORK(&wurb->dequeue_work, urb_dequeue_work);
654
655	if (urb->num_sgs) {
656		ret = qset_add_urb_sg(whc, qset, urb, mem_flags);
657		if (ret == -EINVAL) {
658			qset_free_stds(qset, urb);
659			ret = qset_add_urb_sg_linearize(whc, qset, urb, mem_flags);
660		}
661		if (ret < 0)
662			goto err_no_mem;
663		return 0;
664	}
665
666	ntds_remaining = DIV_ROUND_UP(remaining, QTD_MAX_XFER_SIZE);
667	if (ntds_remaining == 0)
668		ntds_remaining = 1;
669
670	while (ntds_remaining) {
671		struct whc_std *std;
672		size_t std_len;
673
674		std_len = remaining;
675		if (std_len > QTD_MAX_XFER_SIZE)
676			std_len = QTD_MAX_XFER_SIZE;
677
678		std = qset_new_std(whc, qset, urb, mem_flags);
679		if (std == NULL)
680			goto err_no_mem;
681
682		std->dma_addr = transfer_dma;
683		std->len = std_len;
684		std->ntds_remaining = ntds_remaining;
685
686		if (qset_fill_page_list(whc, std, mem_flags) < 0)
687			goto err_no_mem;
688
689		ntds_remaining--;
690		remaining -= std_len;
691		transfer_dma += std_len;
692	}
693
694	return 0;
695
696err_no_mem:
697	qset_free_stds(qset, urb);
698	return -ENOMEM;
699}
700
701/**
702 * qset_remove_urb - remove an URB from the urb queue.
703 *
704 * The URB is returned to the USB subsystem.
705 */
706void qset_remove_urb(struct whc *whc, struct whc_qset *qset,
707			    struct urb *urb, int status)
708{
709	struct wusbhc *wusbhc = &whc->wusbhc;
710	struct whc_urb *wurb = urb->hcpriv;
711
712	usb_hcd_unlink_urb_from_ep(&wusbhc->usb_hcd, urb);
713	/* Drop the lock as urb->complete() may enqueue another urb. */
714	spin_unlock(&whc->lock);
715	wusbhc_giveback_urb(wusbhc, urb, status);
716	spin_lock(&whc->lock);
717
718	kfree(wurb);
719}
720
721/**
722 * get_urb_status_from_qtd - get the completed urb status from qTD status
723 * @urb:    completed urb
724 * @status: qTD status
725 */
726static int get_urb_status_from_qtd(struct urb *urb, u32 status)
727{
728	if (status & QTD_STS_HALTED) {
729		if (status & QTD_STS_DBE)
730			return usb_pipein(urb->pipe) ? -ENOSR : -ECOMM;
731		else if (status & QTD_STS_BABBLE)
732			return -EOVERFLOW;
733		else if (status & QTD_STS_RCE)
734			return -ETIME;
735		return -EPIPE;
736	}
737	if (usb_pipein(urb->pipe)
738	    && (urb->transfer_flags & URB_SHORT_NOT_OK)
739	    && urb->actual_length < urb->transfer_buffer_length)
740		return -EREMOTEIO;
741	return 0;
742}
743
744/**
745 * process_inactive_qtd - process an inactive (but not halted) qTD.
746 *
747 * Update the urb with the transfer bytes from the qTD, if the urb is
748 * completely transferred or (in the case of an IN only) the LPF is
749 * set, then the transfer is complete and the urb should be returned
750 * to the system.
751 */
752void process_inactive_qtd(struct whc *whc, struct whc_qset *qset,
753				 struct whc_qtd *qtd)
754{
755	struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
756	struct urb *urb = std->urb;
757	uint32_t status;
758	bool complete;
759
760	status = le32_to_cpu(qtd->status);
761
762	urb->actual_length += std->len - QTD_STS_TO_LEN(status);
763
764	if (usb_pipein(urb->pipe) && (status & QTD_STS_LAST_PKT))
765		complete = true;
766	else
767		complete = whc_std_last(std);
768
769	qset_remove_qtd(whc, qset);
770	qset_free_std(whc, std);
771
772	/*
773	 * Transfers for this URB are complete?  Then return it to the
774	 * USB subsystem.
775	 */
776	if (complete) {
777		qset_remove_qtds(whc, qset, urb);
778		qset_remove_urb(whc, qset, urb, get_urb_status_from_qtd(urb, status));
779
780		/*
781		 * If iAlt isn't valid then the hardware didn't
782		 * advance iCur. Adjust the start and end pointers to
783		 * match iCur.
784		 */
785		if (!(status & QTD_STS_IALT_VALID))
786			qset->td_start = qset->td_end
787				= QH_STATUS_TO_ICUR(le16_to_cpu(qset->qh.status));
788		qset->pause_after_urb = NULL;
789	}
790}
791
792/**
793 * process_halted_qtd - process a qset with a halted qtd
794 *
795 * Remove all the qTDs for the failed URB and return the failed URB to
796 * the USB subsystem.  Then remove all other qTDs so the qset can be
797 * removed.
798 *
799 * FIXME: this is the point where rate adaptation can be done.  If a
800 * transfer failed because it exceeded the maximum number of retries
801 * then it could be reactivated with a slower rate without having to
802 * remove the qset.
803 */
804void process_halted_qtd(struct whc *whc, struct whc_qset *qset,
805			       struct whc_qtd *qtd)
806{
807	struct whc_std *std = list_first_entry(&qset->stds, struct whc_std, list_node);
808	struct urb *urb = std->urb;
809	int urb_status;
810
811	urb_status = get_urb_status_from_qtd(urb, le32_to_cpu(qtd->status));
812
813	qset_remove_qtds(whc, qset, urb);
814	qset_remove_urb(whc, qset, urb, urb_status);
815
816	list_for_each_entry(std, &qset->stds, list_node) {
817		if (qset->ntds == 0)
818			break;
819		qset_remove_qtd(whc, qset);
820		std->qtd = NULL;
821	}
822
823	qset->remove = 1;
824}
825
826void qset_free(struct whc *whc, struct whc_qset *qset)
827{
828	dma_pool_free(whc->qset_pool, qset, qset->qset_dma);
829}
830
831/**
832 * qset_delete - wait for a qset to be unused, then free it.
833 */
834void qset_delete(struct whc *whc, struct whc_qset *qset)
835{
836	wait_for_completion(&qset->remove_complete);
837	qset_free(whc, qset);
838}