1 files changed, 376 insertions, 0 deletions
diff --git a/drivers/usb/host/whci/asl.c b/drivers/usb/host/whci/asl.c
new file mode 100644
index 000000000..276fb34c8
--- /dev/null
+++ b/drivers/usb/host/whci/asl.c
@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Wireless Host Controller (WHC) asynchronous schedule management.
+ *
+ * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
+ */
+#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+	 * it's no longer valid.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;
+
+		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);
+	}
+}