uhci-q.c

硬实时linux补丁rtai下usb协议栈

		struct rtdm_urb *u = up->urb;

		/* look for pending URB's with identical pipe handle */
		if ((urb->pipe == u->pipe) && (urb->dev == u->dev) &&
		    (u->status == -EINPROGRESS) && (u != urb)) {
			if (!last_urb)
				*start = u->start_frame;
			last_urb = u;
		}
	}

	if (last_urb) {
		*end = (last_urb->start_frame + last_urb->number_of_packets *
				last_urb->interval) & (UHCI_NUMFRAMES-1);
		ret = 0;
	} else
		ret = -1;	/* no previous urb found */

	return ret;
}

static int isochronous_find_start(struct uhci_hcd *uhci, struct rtdm_urb *urb)
{
	int limits;
	unsigned int start = 0, end = 0;

	if (urb->number_of_packets > 900)	/* 900? Why? */
		return -EFBIG;

	limits = isochronous_find_limits(uhci, urb, &start, &end);

	if (urb->transfer_flags & RTDM_URB_ISO_ASAP) {
		if (limits) {
			uhci_get_current_frame_number(uhci);
			urb->start_frame = (uhci->frame_number + 10)
					& (UHCI_NUMFRAMES - 1);
		} else
			urb->start_frame = end;
	} else {
		urb->start_frame &= (UHCI_NUMFRAMES - 1);
		/* FIXME: Sanity check */
	}

	return 0;
}

/*
 * Isochronous transfers
 */
static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct rtdm_urb *urb)
{
	struct uhci_td *td;
	int i, ret, frame;
	int status, destination;

	status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
	destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);

	ret = isochronous_find_start(uhci, urb);
	if (ret)
		return ret;

	frame = urb->start_frame;
	for (i = 0; i < urb->number_of_packets; i++, frame += urb->interval) {
		if (!urb->iso_frame_desc[i].length)
			continue;

		td = uhci_alloc_td(uhci);
		if (!td)
			return -ENOMEM;

		uhci_add_td_to_urb(urb, td);
		uhci_fill_td(td, status, destination | uhci_explen(urb->iso_frame_desc[i].length - 1),
			urb->transfer_dma + urb->iso_frame_desc[i].offset);

		if (i + 1 >= urb->number_of_packets)
			td->status |= cpu_to_le32(TD_CTRL_IOC);

		uhci_insert_td_frame_list(uhci, td, frame);
	}

	return -EINPROGRESS;
}

static int uhci_result_isochronous(struct uhci_hcd *uhci, struct rtdm_urb *urb)
{
	struct uhci_td *td;
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	int status;
	int i, ret = 0;

	urb->actual_length = 0;

	i = 0;
	list_for_each_entry(td, &urbp->td_list, list) {
		int actlength;
		unsigned int ctrlstat = td_status(td);

		if (ctrlstat & TD_CTRL_ACTIVE)
			return -EINPROGRESS;

		actlength = uhci_actual_length(ctrlstat);
		urb->iso_frame_desc[i].actual_length = actlength;
		urb->actual_length += actlength;

		status = uhci_map_status(uhci_status_bits(ctrlstat),
				rtdm_usb_pipeout(urb->pipe));
		urb->iso_frame_desc[i].status = status;
		if (status) {
			urb->error_count++;
			ret = status;
		}

		i++;
	}

	return ret;
}

static struct rtdm_urb *uhci_find_urb_ep(struct uhci_hcd *uhci, struct rtdm_urb *urb)
{
	struct urb_priv *up;

	/* We don't match Isoc transfers since they are special */
	if (rtdm_usb_pipeisoc(urb->pipe))
		return NULL;

	list_for_each_entry(up, &uhci->urb_list, urb_list) {
		struct rtdm_urb *u = up->urb;

		if (u->dev == urb->dev && u->status == -EINPROGRESS) {
			/* For control, ignore the direction */
			if (rtdm_usb_pipecontrol(urb->pipe) &&
			    (u->pipe & ~USB_DIR_IN) == (urb->pipe & ~USB_DIR_IN))
				return u;
			else if (u->pipe == urb->pipe)
				return u;
		}
	}

	return NULL;
}

static int uhci_urb_enqueue(struct usb_hcd *hcd,
		struct rtdm_usb_host_endpoint *ep,
		struct rtdm_urb *urb)
{
	int ret;
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
	unsigned long		context;
	struct rtdm_urb *eurb;
	int bustime;

		rtdm_lock_get_irqsave(&uhci->rt_lock, context);

	ret = urb->status;
	if (ret != -EINPROGRESS)		/* URB already unlinked! */
		goto out;

	eurb = uhci_find_urb_ep(uhci, urb);

	if (!uhci_alloc_urb_priv(uhci, urb)) {
		ret = -ENOMEM;
		goto out;
	}

	switch (rtdm_usb_pipetype(urb->pipe)) {
	case RTDM_PIPE_CONTROL:
		ret = uhci_submit_control(uhci, urb, eurb);
		break;
	case RTDM_PIPE_INTERRUPT:
		if (!eurb) {
			bustime = rtdm_usb_check_bandwidth(urb->dev, urb);
			if (bustime < 0)
				ret = bustime;
			else {
				ret = uhci_submit_interrupt(uhci, urb, eurb);
				if (ret == -EINPROGRESS)
					rtdm_usb_claim_bandwidth(urb->dev, urb, bustime, 0);
			}
		} else {	/* inherit from parent */
			urb->bandwidth = eurb->bandwidth;
			ret = uhci_submit_interrupt(uhci, urb, eurb);
		}
		break;
	case RTDM_PIPE_BULK:
		ret = uhci_submit_bulk(uhci, urb, eurb);
		break;
	case RTDM_PIPE_ISOCHRONOUS:
		bustime = rtdm_usb_check_bandwidth(urb->dev, urb);
		if (bustime < 0) {
			ret = bustime;
			break;
		}

		ret = uhci_submit_isochronous(uhci, urb);
		if (ret == -EINPROGRESS)
			rtdm_usb_claim_bandwidth(urb->dev, urb, bustime, 1);
		break;
	}

	if (ret != -EINPROGRESS) {
		/* Submit failed, so delete it from the urb_list */
		struct urb_priv *urbp = urb->hcpriv;

		list_del_init(&urbp->urb_list);
		uhci_destroy_urb_priv(uhci, urb);
	} else
		ret = 0;

out:
	rtdm_lock_put_irqrestore(&uhci->rt_lock, context);
	return ret;
}

/*
 * Return the result of a transfer
 */
static void uhci_transfer_result(struct uhci_hcd *uhci, struct rtdm_urb *urb)
{
	int ret = -EINPROGRESS;
	struct urb_priv *urbp;

	rtdm_lock_get(&urb->rt_lock);

	urbp = (struct urb_priv *)urb->hcpriv;

	if (urb->status != -EINPROGRESS)	/* URB already dequeued */
		goto out;

	switch (rtdm_usb_pipetype(urb->pipe)) {
	case RTDM_PIPE_CONTROL:
		ret = uhci_result_control(uhci, urb);
		break;
	case RTDM_PIPE_BULK:
	case RTDM_PIPE_INTERRUPT:
		ret = uhci_result_common(uhci, urb);
		break;
	case RTDM_PIPE_ISOCHRONOUS:
		ret = uhci_result_isochronous(uhci, urb);
		break;
	}

	if (ret == -EINPROGRESS)
		goto out;
	urb->status = ret;

	switch (rtdm_usb_pipetype(urb->pipe)) {
		case RTDM_PIPE_CONTROL:
		case RTDM_PIPE_BULK:
		case RTDM_PIPE_ISOCHRONOUS:
			/* Release bandwidth for Interrupt or Isoc. transfers */
			if (urb->bandwidth)
				rtdm_usb_release_bandwidth(urb->dev, urb, 1);
			uhci_unlink_generic(uhci, urb);
			break;
		case RTDM_PIPE_INTERRUPT:
			/* Release bandwidth for Interrupt or Isoc. transfers */
			/* Make sure we don't release if we have a queued URB */
			if (list_empty(&urbp->queue_list) && urb->bandwidth)
				rtdm_usb_release_bandwidth(urb->dev, urb, 0);
			else
				/* bandwidth was passed on to queued URB, */
				/* so don't let usb_unlink_urb() release it */
				urb->bandwidth = 0;
			uhci_unlink_generic(uhci, urb);
			break;
		default:
			rtdm_dev_info(uhci_dev(uhci), "%s: unknown pipe type %d "
					"for urb %p\n",
					__FUNCTION__, rtdm_usb_pipetype(urb->pipe), urb);
	}

	/* Move it from uhci->urb_list to uhci->complete_list */
	uhci_moveto_complete(uhci, urbp);

out:
		rtdm_lock_put(&urb->rt_lock);
}

static void uhci_unlink_generic(struct uhci_hcd *uhci, struct rtdm_urb *urb)
{
	struct list_head *head;
	struct uhci_td *td;
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	int prevactive = 0;

	uhci_dec_fsbr(uhci, urb);	/* Safe since it checks */

	/*
	 * Now we need to find out what the last successful toggle was
	 * so we can update the local data toggle for the next transfer
	 *
	 * There are 2 ways the last successful completed TD is found:
	 *
	 * 1) The TD is NOT active and the actual length < expected length
	 * 2) The TD is NOT active and it's the last TD in the chain
	 *
	 * and a third way the first uncompleted TD is found:
	 *
	 * 3) The TD is active and the previous TD is NOT active
	 *
	 * Control and Isochronous ignore the toggle, so this is safe
	 * for all types
	 *
	 * FIXME: The toggle fixups won't be 100% reliable until we
	 * change over to using a single queue for each endpoint and
	 * stop the queue before unlinking.
	 */
	head = &urbp->td_list;
	list_for_each_entry(td, head, list) {
		unsigned int ctrlstat = td_status(td);

		if (!(ctrlstat & TD_CTRL_ACTIVE) &&
				(uhci_actual_length(ctrlstat) <
				 uhci_expected_length(td_token(td)) ||
				td->list.next == head))
			rtdm_usb_settoggle(urb->dev, uhci_endpoint(td_token(td)),
				uhci_packetout(td_token(td)),
				uhci_toggle(td_token(td)) ^ 1);
		else if ((ctrlstat & TD_CTRL_ACTIVE) && !prevactive)
			rtdm_usb_settoggle(urb->dev, uhci_endpoint(td_token(td)),
				uhci_packetout(td_token(td)),
				uhci_toggle(td_token(td)));

		prevactive = ctrlstat & TD_CTRL_ACTIVE;
	}

	uhci_delete_queued_urb(uhci, urb);

	/* The interrupt loop will reclaim the QH's */
	uhci_remove_qh(uhci, urbp->qh);
	urbp->qh = NULL;
}

static int uhci_urb_dequeue(struct usb_hcd *hcd, struct rtdm_urb *urb)
{
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
	unsigned long		context;
	struct urb_priv *urbp;

	rtdm_lock_get_irqsave(&uhci->rt_lock, context);
	urbp = urb->hcpriv;
	if (!urbp)			/* URB was never linked! */
		goto done;
	list_del_init(&urbp->urb_list);

	uhci_unlink_generic(uhci, urb);

	uhci_get_current_frame_number(uhci);
	if (uhci->frame_number + uhci->is_stopped != uhci->urb_remove_age) {
		uhci_remove_pending_urbps(uhci);
		uhci->urb_remove_age = uhci->frame_number;
	}

	/* If we're the first, set the next interrupt bit */
	if (list_empty(&uhci->urb_remove_list))
		uhci_set_next_interrupt(uhci);
	list_add_tail(&urbp->urb_list, &uhci->urb_remove_list);

done:
	rtdm_lock_put_irqrestore(&uhci->rt_lock, context);
	return 0;
}

static int uhci_fsbr_timeout(struct uhci_hcd *uhci, struct rtdm_urb *urb)
{
	struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
	struct list_head *head;
	struct uhci_td *td;
	int count = 0;

	uhci_dec_fsbr(uhci, urb);

	urbp->fsbr_timeout = 1;

	/*
	 * Ideally we would want to fix qh->element as well, but it's
	 * read/write by the HC, so that can introduce a race. It's not
	 * really worth the hassle
	 */

	head = &urbp->td_list;
	list_for_each_entry(td, head, list) {
		/*
		 * Make sure we don't do the last one (since it'll have the
		 * TERM bit set) as well as we skip every so many TD's to
		 * make sure it doesn't hog the bandwidth
		 */
		if (td->list.next != head && (count % DEPTH_INTERVAL) ==
				(DEPTH_INTERVAL - 1))
			td->link |= UHCI_PTR_DEPTH;

		count++;
	}

	return 0;
}

static void uhci_free_pending_qhs(struct uhci_hcd *uhci)
{
	struct uhci_qh *qh, *tmp;

	list_for_each_entry_safe(qh, tmp, &uhci->qh_remove_list, remove_list) {
		list_del_init(&qh->remove_list);

		uhci_free_qh(uhci, qh);
	}
}

static void uhci_free_pending_tds(struct uhci_hcd *uhci)
{
	struct uhci_td *td, *tmp;

	list_for_each_entry_safe(td, tmp, &uhci->td_remove_list, remove_list) {
		list_del_init(&td->remove_list);

		uhci_free_td(uhci, td);
	}
}

static void
		uhci_finish_urb(struct usb_hcd *hcd, struct rtdm_urb *urb)
{
	struct uhci_hcd *uhci = hcd_to_uhci(hcd);

	uhci_destroy_urb_priv(uhci, urb);

	rtdm_lock_put (&uhci->rt_lock);
	rtdm_usb_hcd_giveback_urb(hcd, urb);
	rtdm_lock_get (&uhci->rt_lock);
}

static void uhci_finish_completion(struct uhci_hcd *uhci)
{
	struct urb_priv *urbp, *tmp;

	list_for_each_entry_safe(urbp, tmp, &uhci->complete_list, urb_list) {
		struct rtdm_urb *urb = urbp->urb;

		list_del_init(&urbp->urb_list);
		uhci_finish_urb(uhci_to_hcd(uhci), urb);
	}
}

static void uhci_remove_pending_urbps(struct uhci_hcd *uhci)
{

	/* Splice the urb_remove_list onto the end of the complete_list */
	list_splice_init(&uhci->urb_remove_list, uhci->complete_list.prev);
}

/* Process events in the schedule, but only in one thread at a time */
static void uhci_scan_schedule(struct uhci_hcd *uhci, struct pt_regs *regs)
{
	struct urb_priv *urbp, *tmp;

	/* Don't allow re-entrant calls */
	if (uhci->scan_in_progress) {
		uhci->need_rescan = 1;
		return;
	}
	uhci->scan_in_progress = 1;
 rescan:
	uhci->need_rescan = 0;

	uhci_clear_next_interrupt(uhci);
	uhci_get_current_frame_number(uhci);

	if (uhci->frame_number + uhci->is_stopped != uhci->qh_remove_age)
		uhci_free_pending_qhs(uhci);
	if (uhci->frame_number + uhci->is_stopped != uhci->td_remove_age)
		uhci_free_pending_tds(uhci);
	if (uhci->frame_number + uhci->is_stopped != uhci->urb_remove_age)
		uhci_remove_pending_urbps(uhci);

	/* Walk the list of pending URBs to see which ones completed
	 * (must be _safe because uhci_transfer_result() dequeues URBs) */
	list_for_each_entry_safe(urbp, tmp, &uhci->urb_list, urb_list) {
		struct rtdm_urb *urb = urbp->urb;

		/* Checks the status and does all of the magic necessary */
		uhci_transfer_result(uhci, urb);
	}
	uhci_finish_completion(uhci);

	/* If the controller is stopped, we can finish these off right now */
	if (uhci->is_stopped) {
		uhci_free_pending_qhs(uhci);
		uhci_free_pending_tds(uhci);
		uhci_remove_pending_urbps(uhci);
	}

	if (uhci->need_rescan)
		goto rescan;
	uhci->scan_in_progress = 0;

	if (list_empty(&uhci->urb_remove_list) &&
	    list_empty(&uhci->td_remove_list) &&
	    list_empty(&uhci->qh_remove_list))
		uhci_clear_next_interrupt(uhci);
	else
		uhci_set_next_interrupt(uhci);

	/* Wake up anyone waiting for an URB to complete */
	wake_up_all(&uhci->waitqh);
}

static void check_fsbr(struct uhci_hcd *uhci)
{
	struct urb_priv *up;

	list_for_each_entry(up, &uhci->urb_list, urb_list) {
		struct rtdm_urb *u = up->urb;

		rtdm_lock_get(&u->rt_lock);

		/* Check if the FSBR timed out */
		if (up->fsbr && !up->fsbr_timeout && time_after_eq(jiffies, up->fsbrtime + IDLE_TIMEOUT))
			uhci_fsbr_timeout(uhci, u);

		rtdm_lock_put(&u->rt_lock);
	}

	/* Really disable FSBR */
	if (!uhci->fsbr && uhci->fsbrtimeout && time_after_eq(jiffies, uhci->fsbrtimeout)) {
		uhci->fsbrtimeout = 0;
		uhci->skel_term_qh->link = UHCI_PTR_TERM;
	}
}