Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 831 insertions, 0 deletions

diff --git a/drivers/usb/host/whci/qset.c b/drivers/usb/host/whci/qset.c
new file mode 100644
index 000000000..925166a20
--- /dev/null
+++ b/drivers/usb/host/whci/qset.c
@@ -0,0 +1,831 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Wireless Host Controller (WHC) qset management.
+ *
+ * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
+ */
+#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_zalloc(whc->qset_pool, mem_flags, &dma);
+	if (qset == NULL)
+		return NULL;
+
+	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_le64(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 (!dma_mapping_error(whc->wusbhc.dev, 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);
+	if (dma_mapping_error(whc->wusbhc.dev, std->dma_addr)) {
+		kfree(std->pl_virt);
+		return -EFAULT;
+	}
+
+	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)
+		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 *new_pl_virt;
+	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_mapped_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 && 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);
+
+			new_pl_virt = krealloc(std->pl_virt, pl_len, mem_flags);
+			if (new_pl_virt == NULL) {
+				kfree(std->pl_virt);
+				std->pl_virt = NULL;
+				return -ENOMEM;
+			}
+			std->pl_virt = new_pl_virt;
+
+			for (;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);
+			}
+
+			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->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt,
+						       pl_len, DMA_TO_DEVICE);
+			if (dma_mapping_error(whc->wusbhc.dev, std->dma_addr))
+				return -EFAULT;
+			std->ntds_remaining = ntds--;
+		}
+	}
+	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_mapped_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 (dma_mapping_error(&whc->umc->dev, std->dma_addr))
+			return -EFAULT;
+
+		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 transferred 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);
+}