drivers/usb/host/whci/asl.c - arm/linux - Git at Google

 /*
  * Wireless Host Controller (WHC) asynchronous schedule 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/gfp.h>
 #include <linux/dma-mapping.h>
 #include <linux/uwb/umc.h>
 #include <linux/usb.h>

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

 #include "whcd.h"

 static void qset_get_next_prev(struct whc *whc, struct whc_qset *qset,
 			       struct whc_qset **next, struct whc_qset **prev)
 {
 	struct list_head *n, *p;

 	BUG_ON(list_empty(&whc->async_list));

 	n = qset->list_node.next;
 	if (n == &whc->async_list)
 		n = n->next;
 	p = qset->list_node.prev;
 	if (p == &whc->async_list)
 		p = p->prev;

 	*next = container_of(n, struct whc_qset, list_node);
 	*prev = container_of(p, struct whc_qset, list_node);

 }

 static void asl_qset_insert_begin(struct whc *whc, struct whc_qset *qset)
 {
 	list_move(&qset->list_node, &whc->async_list);
 	qset->in_sw_list = true;
 }

 static void asl_qset_insert(struct whc *whc, struct whc_qset *qset)
 {
 	struct whc_qset *next, *prev;

 	qset_clear(whc, qset);

 	/* Link into ASL. */
 	qset_get_next_prev(whc, qset, &next, &prev);
 	whc_qset_set_link_ptr(&qset->qh.link, next->qset_dma);
 	whc_qset_set_link_ptr(&prev->qh.link, qset->qset_dma);
 	qset->in_hw_list = true;
 }

 static void asl_qset_remove(struct whc *whc, struct whc_qset *qset)
 {
 	struct whc_qset *prev, *next;

 	qset_get_next_prev(whc, qset, &next, &prev);

 	list_move(&qset->list_node, &whc->async_removed_list);
 	qset->in_sw_list = false;

 	/*
 	 * No more qsets in the ASL?  The caller must stop the ASL as
 	 * it's no longer valid.
 	 */
 	if (list_empty(&whc->async_list))
 		return;

 	/* Remove from ASL. */
 	whc_qset_set_link_ptr(&prev->qh.link, next->qset_dma);
 	qset->in_hw_list = false;
 }

 /**
  * process_qset - process any recently inactivated or halted qTDs in a
  * qset.
  *
  * After inactive qTDs are removed, new qTDs can be added if the
  * urb queue still contains URBs.
  *
  * Returns any additional WUSBCMD bits for the ASL sync command (i.e.,
  * WUSBCMD_ASYNC_QSET_RM if a halted qset was removed).
  */
 static uint32_t process_qset(struct whc *whc, struct whc_qset *qset)
 {
 	enum whc_update update = 0;
 	uint32_t status = 0;

 	while (qset->ntds) {
 		struct whc_qtd *td;
 		int t;

 		t = qset->td_start;
 		td = &qset->qtd[qset->td_start];
 		status = le32_to_cpu(td->status);

 		/*
 		 * Nothing to do with a still active qTD.
 		 */
 		if (status & QTD_STS_ACTIVE)
 			break;

 		if (status & QTD_STS_HALTED) {
 			/* Ug, an error. */
 			process_halted_qtd(whc, qset, td);
 			/* A halted qTD always triggers an update
 			   because the qset was either removed or
 			   reactivated. */
 			update |= WHC_UPDATE_UPDATED;
 			goto done;
 		}

 		/* Mmm, a completed qTD. */
 		process_inactive_qtd(whc, qset, td);
 	}

 	if (!qset->remove)
 		update |= qset_add_qtds(whc, qset);

 done:
 	/*
 	 * Remove this qset from the ASL if requested, but only if has
 	 * no qTDs.
 	 */
 	if (qset->remove && qset->ntds == 0) {
 		asl_qset_remove(whc, qset);
 		update |= WHC_UPDATE_REMOVED;
 	}
 	return update;
 }

 void asl_start(struct whc *whc)
 {
 	struct whc_qset *qset;

 	qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);

 	le_writeq(qset->qset_dma | QH_LINK_NTDS(8), whc->base + WUSBASYNCLISTADDR);

 	whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, WUSBCMD_ASYNC_EN);
 	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 		      WUSBSTS_ASYNC_SCHED, WUSBSTS_ASYNC_SCHED,
 		      1000, "start ASL");
 }

 void asl_stop(struct whc *whc)
 {
 	whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, 0);
 	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 		      WUSBSTS_ASYNC_SCHED, 0,
 		      1000, "stop ASL");
 }

 /**
  * asl_update - request an ASL update and wait for the hardware to be synced
  * @whc: the WHCI HC
  * @wusbcmd: WUSBCMD value to start the update.
  *
  * If the WUSB HC is inactive (i.e., the ASL is stopped) then the
  * update must be skipped as the hardware may not respond to update
  * requests.
  */
 void asl_update(struct whc *whc, uint32_t wusbcmd)
 {
 	struct wusbhc *wusbhc = &whc->wusbhc;
 	long t;

 	mutex_lock(&wusbhc->mutex);
 	if (wusbhc->active) {
 		whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
 		t = wait_event_timeout(
 			whc->async_list_wq,
 			(le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0,
 			msecs_to_jiffies(1000));
 		if (t == 0)
 			whc_hw_error(whc, "ASL update timeout");
 	}
 	mutex_unlock(&wusbhc->mutex);
 }

 /**
  * scan_async_work - scan the ASL for qsets to process.
  *
  * Process each qset in the ASL in turn and then signal the WHC that
  * the ASL has been updated.
  *
  * Then start, stop or update the asynchronous schedule as required.
  */
 void scan_async_work(struct work_struct *work)
 {
 	struct whc *whc = container_of(work, struct whc, async_work);
 	struct whc_qset *qset, *t;
 	enum whc_update update = 0;

 	spin_lock_irq(&whc->lock);

 	/*
 	 * Transerve the software list backwards so new qsets can be
 	 * safely inserted into the ASL without making it non-circular.
 	 */
 	list_for_each_entry_safe_reverse(qset, t, &whc->async_list, list_node) {
 		if (!qset->in_hw_list) {
 			asl_qset_insert(whc, qset);
 			update |= WHC_UPDATE_ADDED;
 		}

 		update |= process_qset(whc, qset);
 	}

 	spin_unlock_irq(&whc->lock);

 	if (update) {
 		uint32_t wusbcmd = WUSBCMD_ASYNC_UPDATED | WUSBCMD_ASYNC_SYNCED_DB;
 		if (update & WHC_UPDATE_REMOVED)
 			wusbcmd |= WUSBCMD_ASYNC_QSET_RM;
 		asl_update(whc, wusbcmd);
 	}

 	/*
 	 * Now that the ASL is updated, complete the removal of any
 	 * removed qsets.
 	 *
 	 * If the qset was to be reset, do so and reinsert it into the
 	 * ASL if it has pending transfers.
 	 */
 	spin_lock_irq(&whc->lock);

 	list_for_each_entry_safe(qset, t, &whc->async_removed_list, list_node) {
 		qset_remove_complete(whc, qset);
 		if (qset->reset) {
 			qset_reset(whc, qset);
 			if (!list_empty(&qset->stds)) {
 				asl_qset_insert_begin(whc, qset);
 				queue_work(whc->workqueue, &whc->async_work);
 			}
 		}
 	}

 	spin_unlock_irq(&whc->lock);
 }

 /**
  * asl_urb_enqueue - queue an URB onto the asynchronous list (ASL).
  * @whc: the WHCI host controller
  * @urb: the URB to enqueue
  * @mem_flags: flags for any memory allocations
  *
  * The qset for the endpoint is obtained and the urb queued on to it.
  *
  * Work is scheduled to update the hardware's view of the ASL.
  */
 int asl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
 {
 	struct whc_qset *qset;
 	int err;
 	unsigned long flags;

 	spin_lock_irqsave(&whc->lock, flags);

 	err = usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
 	if (err < 0) {
 		spin_unlock_irqrestore(&whc->lock, flags);
 		return err;
 	}

 	qset = get_qset(whc, urb, GFP_ATOMIC);
 	if (qset == NULL)
 		err = -ENOMEM;
 	else
 		err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
 	if (!err) {
 		if (!qset->in_sw_list && !qset->remove)
 			asl_qset_insert_begin(whc, qset);
 	} else
 		usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);

 	spin_unlock_irqrestore(&whc->lock, flags);

 	if (!err)
 		queue_work(whc->workqueue, &whc->async_work);

 	return err;
 }

 /**
  * asl_urb_dequeue - remove an URB (qset) from the async list.
  * @whc: the WHCI host controller
  * @urb: the URB to dequeue
  * @status: the current status of the URB
  *
  * URBs that do yet have qTDs can simply be removed from the software
  * queue, otherwise the qset must be removed from the ASL so the qTDs
  * can be removed.
  */
 int asl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
 {
 	struct whc_urb *wurb = urb->hcpriv;
 	struct whc_qset *qset = wurb->qset;
 	struct whc_std *std, *t;
 	bool has_qtd = false;
 	int ret;
 	unsigned long flags;

 	spin_lock_irqsave(&whc->lock, flags);

 	ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
 	if (ret < 0)
 		goto out;

 	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
 		if (std->urb == urb) {
 			if (std->qtd)
 				has_qtd = true;
 			qset_free_std(whc, std);
 		} else
 			std->qtd = NULL; /* so this std is re-added when the qset is */
 	}

 	if (has_qtd) {
 		asl_qset_remove(whc, qset);
 		wurb->status = status;
 		wurb->is_async = true;
 		queue_work(whc->workqueue, &wurb->dequeue_work);
 	} else
 		qset_remove_urb(whc, qset, urb, status);
 out:
 	spin_unlock_irqrestore(&whc->lock, flags);

 	return ret;
 }

 /**
  * asl_qset_delete - delete a qset from the ASL
  */
 void asl_qset_delete(struct whc *whc, struct whc_qset *qset)
 {
 	qset->remove = 1;
 	queue_work(whc->workqueue, &whc->async_work);
 	qset_delete(whc, qset);
 }

 /**
  * asl_init - initialize the asynchronous schedule list
  *
  * A dummy qset with no qTDs is added to the ASL to simplify removing
  * qsets (no need to stop the ASL when the last qset is removed).
  */
 int asl_init(struct whc *whc)
 {
 	struct whc_qset *qset;

 	qset = qset_alloc(whc, GFP_KERNEL);
 	if (qset == NULL)
 		return -ENOMEM;

 	asl_qset_insert_begin(whc, qset);
 	asl_qset_insert(whc, qset);

 	return 0;
 }

 /**
  * asl_clean_up - free ASL resources
  *
  * The ASL is stopped and empty except for the dummy qset.
  */
 void asl_clean_up(struct whc *whc)
 {
 	struct whc_qset *qset;

 	if (!list_empty(&whc->async_list)) {
 		qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);
 		list_del(&qset->list_node);
 		qset_free(whc, qset);
 	}
 }
	/*
	* Wireless Host Controller (WHC) asynchronous schedule 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/gfp.h>
	#include <linux/dma-mapping.h>
	#include <linux/uwb/umc.h>
	#include <linux/usb.h>

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

	#include "whcd.h"

	static void qset_get_next_prev(struct whc whc, struct whc_qset qset,
	struct whc_qset next, struct whc_qset prev)
	{
	struct list_head n, p;

	BUG_ON(list_empty(&whc->async_list));

	n = qset->list_node.next;
	if (n == &whc->async_list)
	n = n->next;
	p = qset->list_node.prev;
	if (p == &whc->async_list)
	p = p->prev;

	*next = container_of(n, struct whc_qset, list_node);
	*prev = container_of(p, struct whc_qset, list_node);

	}

	static void asl_qset_insert_begin(struct whc whc, struct whc_qset qset)
	{
	list_move(&qset->list_node, &whc->async_list);
	qset->in_sw_list = true;
	}

	static void asl_qset_insert(struct whc whc, struct whc_qset qset)
	{
	struct whc_qset next, prev;

	qset_clear(whc, qset);

	/* Link into ASL. */
	qset_get_next_prev(whc, qset, &next, &prev);
	whc_qset_set_link_ptr(&qset->qh.link, next->qset_dma);
	whc_qset_set_link_ptr(&prev->qh.link, qset->qset_dma);
	qset->in_hw_list = true;
	}

	static void asl_qset_remove(struct whc whc, struct whc_qset qset)
	{
	struct whc_qset prev, next;

	qset_get_next_prev(whc, qset, &next, &prev);

	list_move(&qset->list_node, &whc->async_removed_list);
	qset->in_sw_list = false;

	/*
	* No more qsets in the ASL? The caller must stop the ASL as
	* it's no longer valid.
	*/
	if (list_empty(&whc->async_list))
	return;

	/* Remove from ASL. */
	whc_qset_set_link_ptr(&prev->qh.link, next->qset_dma);
	qset->in_hw_list = false;
	}

	/**
	* process_qset - process any recently inactivated or halted qTDs in a
	* qset.
	*
	* After inactive qTDs are removed, new qTDs can be added if the
	* urb queue still contains URBs.
	*
	* Returns any additional WUSBCMD bits for the ASL sync command (i.e.,
	* WUSBCMD_ASYNC_QSET_RM if a halted qset was removed).
	*/
	static uint32_t process_qset(struct whc whc, struct whc_qset qset)
	{
	enum whc_update update = 0;
	uint32_t status = 0;

	while (qset->ntds) {
	struct whc_qtd *td;
	int t;

	t = qset->td_start;
	td = &qset->qtd[qset->td_start];
	status = le32_to_cpu(td->status);

	/*
	* Nothing to do with a still active qTD.
	*/
	if (status & QTD_STS_ACTIVE)
	break;

	if (status & QTD_STS_HALTED) {
	/* Ug, an error. */
	process_halted_qtd(whc, qset, td);
	/* A halted qTD always triggers an update
	because the qset was either removed or
	reactivated. */
	update \|= WHC_UPDATE_UPDATED;
	goto done;
	}

	/* Mmm, a completed qTD. */
	process_inactive_qtd(whc, qset, td);
	}

	if (!qset->remove)
	update \|= qset_add_qtds(whc, qset);

	done:
	/*
	* Remove this qset from the ASL if requested, but only if has
	* no qTDs.
	*/
	if (qset->remove && qset->ntds == 0) {
	asl_qset_remove(whc, qset);
	update \|= WHC_UPDATE_REMOVED;
	}
	return update;
	}

	void asl_start(struct whc *whc)
	{
	struct whc_qset *qset;

	qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);

	le_writeq(qset->qset_dma \| QH_LINK_NTDS(8), whc->base + WUSBASYNCLISTADDR);

	whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, WUSBCMD_ASYNC_EN);
	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
	WUSBSTS_ASYNC_SCHED, WUSBSTS_ASYNC_SCHED,
	1000, "start ASL");
	}

	void asl_stop(struct whc *whc)
	{
	whc_write_wusbcmd(whc, WUSBCMD_ASYNC_EN, 0);
	whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
	WUSBSTS_ASYNC_SCHED, 0,
	1000, "stop ASL");
	}

	/**
	* asl_update - request an ASL update and wait for the hardware to be synced
	* @whc: the WHCI HC
	* @wusbcmd: WUSBCMD value to start the update.
	*
	* If the WUSB HC is inactive (i.e., the ASL is stopped) then the
	* update must be skipped as the hardware may not respond to update
	* requests.
	*/
	void asl_update(struct whc *whc, uint32_t wusbcmd)
	{
	struct wusbhc *wusbhc = &whc->wusbhc;
	long t;

	mutex_lock(&wusbhc->mutex);
	if (wusbhc->active) {
	whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
	t = wait_event_timeout(
	whc->async_list_wq,
	(le_readl(whc->base + WUSBCMD) & WUSBCMD_ASYNC_UPDATED) == 0,
	msecs_to_jiffies(1000));
	if (t == 0)
	whc_hw_error(whc, "ASL update timeout");
	}
	mutex_unlock(&wusbhc->mutex);
	}

	/**
	* scan_async_work - scan the ASL for qsets to process.
	*
	* Process each qset in the ASL in turn and then signal the WHC that
	* the ASL has been updated.
	*
	* Then start, stop or update the asynchronous schedule as required.
	*/
	void scan_async_work(struct work_struct *work)
	{
	struct whc *whc = container_of(work, struct whc, async_work);
	struct whc_qset qset, t;
	enum whc_update update = 0;

	spin_lock_irq(&whc->lock);

	/*
	* Transerve the software list backwards so new qsets can be
	* safely inserted into the ASL without making it non-circular.
	*/
	list_for_each_entry_safe_reverse(qset, t, &whc->async_list, list_node) {
	if (!qset->in_hw_list) {
	asl_qset_insert(whc, qset);
	update \|= WHC_UPDATE_ADDED;
	}

	update \|= process_qset(whc, qset);
	}

	spin_unlock_irq(&whc->lock);

	if (update) {
	uint32_t wusbcmd = WUSBCMD_ASYNC_UPDATED \| WUSBCMD_ASYNC_SYNCED_DB;
	if (update & WHC_UPDATE_REMOVED)
	wusbcmd \|= WUSBCMD_ASYNC_QSET_RM;
	asl_update(whc, wusbcmd);
	}

	/*
	* Now that the ASL is updated, complete the removal of any
	* removed qsets.
	*
	* If the qset was to be reset, do so and reinsert it into the
	* ASL if it has pending transfers.
	*/
	spin_lock_irq(&whc->lock);

	list_for_each_entry_safe(qset, t, &whc->async_removed_list, list_node) {
	qset_remove_complete(whc, qset);
	if (qset->reset) {
	qset_reset(whc, qset);
	if (!list_empty(&qset->stds)) {
	asl_qset_insert_begin(whc, qset);
	queue_work(whc->workqueue, &whc->async_work);
	}
	}
	}

	spin_unlock_irq(&whc->lock);
	}

	/**
	* asl_urb_enqueue - queue an URB onto the asynchronous list (ASL).
	* @whc: the WHCI host controller
	* @urb: the URB to enqueue
	* @mem_flags: flags for any memory allocations
	*
	* The qset for the endpoint is obtained and the urb queued on to it.
	*
	* Work is scheduled to update the hardware's view of the ASL.
	*/
	int asl_urb_enqueue(struct whc whc, struct urb urb, gfp_t mem_flags)
	{
	struct whc_qset *qset;
	int err;
	unsigned long flags;

	spin_lock_irqsave(&whc->lock, flags);

	err = usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
	if (err < 0) {
	spin_unlock_irqrestore(&whc->lock, flags);
	return err;
	}

	qset = get_qset(whc, urb, GFP_ATOMIC);
	if (qset == NULL)
	err = -ENOMEM;
	else
	err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
	if (!err) {
	if (!qset->in_sw_list && !qset->remove)
	asl_qset_insert_begin(whc, qset);
	} else
	usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);

	spin_unlock_irqrestore(&whc->lock, flags);

	if (!err)
	queue_work(whc->workqueue, &whc->async_work);

	return err;
	}

	/**
	* asl_urb_dequeue - remove an URB (qset) from the async list.
	* @whc: the WHCI host controller
	* @urb: the URB to dequeue
	* @status: the current status of the URB
	*
	* URBs that do yet have qTDs can simply be removed from the software
	* queue, otherwise the qset must be removed from the ASL so the qTDs
	* can be removed.
	*/
	int asl_urb_dequeue(struct whc whc, struct urb urb, int status)
	{
	struct whc_urb *wurb = urb->hcpriv;
	struct whc_qset *qset = wurb->qset;
	struct whc_std std, t;
	bool has_qtd = false;
	int ret;
	unsigned long flags;

	spin_lock_irqsave(&whc->lock, flags);

	ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
	if (ret < 0)
	goto out;

	list_for_each_entry_safe(std, t, &qset->stds, list_node) {
	if (std->urb == urb) {
	if (std->qtd)
	has_qtd = true;
	qset_free_std(whc, std);
	} else
	std->qtd = NULL; /* so this std is re-added when the qset is */
	}

	if (has_qtd) {
	asl_qset_remove(whc, qset);
	wurb->status = status;
	wurb->is_async = true;
	queue_work(whc->workqueue, &wurb->dequeue_work);
	} else
	qset_remove_urb(whc, qset, urb, status);
	out:
	spin_unlock_irqrestore(&whc->lock, flags);

	return ret;
	}

	/**
	* asl_qset_delete - delete a qset from the ASL
	*/
	void asl_qset_delete(struct whc whc, struct whc_qset qset)
	{
	qset->remove = 1;
	queue_work(whc->workqueue, &whc->async_work);
	qset_delete(whc, qset);
	}

	/**
	* asl_init - initialize the asynchronous schedule list
	*
	* A dummy qset with no qTDs is added to the ASL to simplify removing
	* qsets (no need to stop the ASL when the last qset is removed).
	*/
	int asl_init(struct whc *whc)
	{
	struct whc_qset *qset;

	qset = qset_alloc(whc, GFP_KERNEL);
	if (qset == NULL)
	return -ENOMEM;

	asl_qset_insert_begin(whc, qset);
	asl_qset_insert(whc, qset);

	return 0;
	}

	/**
	* asl_clean_up - free ASL resources
	*
	* The ASL is stopped and empty except for the dummy qset.
	*/
	void asl_clean_up(struct whc *whc)
	{
	struct whc_qset *qset;

	if (!list_empty(&whc->async_list)) {
	qset = list_first_entry(&whc->async_list, struct whc_qset, list_node);
	list_del(&qset->list_node);
	qset_free(whc, qset);
	}
	}