hcd.c

linux-2.6.15.6

	int		is_iso = usb_pipeisoc (pipe);
	int		old_alloc = dev->bus->bandwidth_allocated;
	int		new_alloc;


	bustime = NS_TO_US (usb_calc_bus_time (dev->speed, is_in, is_iso,
			usb_maxpacket (dev, pipe, !is_in)));
	if (is_iso)
		bustime /= urb->number_of_packets;

	new_alloc = old_alloc + (int) bustime;
	if (new_alloc > FRAME_TIME_MAX_USECS_ALLOC) {
#ifdef	DEBUG
		char	*mode = 
#ifdef CONFIG_USB_BANDWIDTH
			"";
#else
			"would have ";
#endif
		dev_dbg (&dev->dev, "usb_check_bandwidth %sFAILED: %d + %ld = %d usec\n",
			mode, old_alloc, bustime, new_alloc);
#endif
#ifdef CONFIG_USB_BANDWIDTH
		bustime = -ENOSPC;	/* report error */
#endif
	}

	return bustime;
}
EXPORT_SYMBOL (usb_check_bandwidth);


/**
 * usb_claim_bandwidth - records bandwidth for a periodic transfer
 * @dev: source/target of request
 * @urb: request (urb->dev == dev)
 * @bustime: bandwidth consumed, in (average) microseconds per frame
 * @isoc: true iff the request is isochronous
 *
 * Bus bandwidth reservations are recorded purely for diagnostic purposes.
 * HCDs are expected not to overcommit periodic bandwidth, and to record such
 * reservations whenever endpoints are added to the periodic schedule.
 *
 * FIXME averaging per-frame is suboptimal.  Better to sum over the HCD's
 * entire periodic schedule ... 32 frames for OHCI, 1024 for UHCI, settable
 * for EHCI (256/512/1024 frames, default 1024) and have the bus expose how
 * large its periodic schedule is.
 */
void usb_claim_bandwidth (struct usb_device *dev, struct urb *urb, int bustime, int isoc)
{
	dev->bus->bandwidth_allocated += bustime;
	if (isoc)
		dev->bus->bandwidth_isoc_reqs++;
	else
		dev->bus->bandwidth_int_reqs++;
	urb->bandwidth = bustime;

#ifdef USB_BANDWIDTH_MESSAGES
	dev_dbg (&dev->dev, "bandwidth alloc increased by %d (%s) to %d for %d requesters\n",
		bustime,
		isoc ? "ISOC" : "INTR",
		dev->bus->bandwidth_allocated,
		dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs);
#endif
}
EXPORT_SYMBOL (usb_claim_bandwidth);


/**
 * usb_release_bandwidth - reverses effect of usb_claim_bandwidth()
 * @dev: source/target of request
 * @urb: request (urb->dev == dev)
 * @isoc: true iff the request is isochronous
 *
 * This records that previously allocated bandwidth has been released.
 * Bandwidth is released when endpoints are removed from the host controller's
 * periodic schedule.
 */
void usb_release_bandwidth (struct usb_device *dev, struct urb *urb, int isoc)
{
	dev->bus->bandwidth_allocated -= urb->bandwidth;
	if (isoc)
		dev->bus->bandwidth_isoc_reqs--;
	else
		dev->bus->bandwidth_int_reqs--;

#ifdef USB_BANDWIDTH_MESSAGES
	dev_dbg (&dev->dev, "bandwidth alloc reduced by %d (%s) to %d for %d requesters\n",
		urb->bandwidth,
		isoc ? "ISOC" : "INTR",
		dev->bus->bandwidth_allocated,
		dev->bus->bandwidth_int_reqs + dev->bus->bandwidth_isoc_reqs);
#endif
	urb->bandwidth = 0;
}
EXPORT_SYMBOL (usb_release_bandwidth);


/*-------------------------------------------------------------------------*/

/*
 * Generic HC operations.
 */

/*-------------------------------------------------------------------------*/

static void urb_unlink (struct urb *urb)
{
	unsigned long		flags;

	/* Release any periodic transfer bandwidth */
	if (urb->bandwidth)
		usb_release_bandwidth (urb->dev, urb,
			usb_pipeisoc (urb->pipe));

	/* clear all state linking urb to this dev (and hcd) */

	spin_lock_irqsave (&hcd_data_lock, flags);
	list_del_init (&urb->urb_list);
	spin_unlock_irqrestore (&hcd_data_lock, flags);
	usb_put_dev (urb->dev);
}


/* may be called in any context with a valid urb->dev usecount
 * caller surrenders "ownership" of urb
 * expects usb_submit_urb() to have sanity checked and conditioned all
 * inputs in the urb
 */
static int hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
{
	int			status;
	struct usb_hcd		*hcd = urb->dev->bus->hcpriv;
	struct usb_host_endpoint *ep;
	unsigned long		flags;

	if (!hcd)
		return -ENODEV;

	usbmon_urb_submit(&hcd->self, urb);

	/*
	 * Atomically queue the urb,  first to our records, then to the HCD.
	 * Access to urb->status is controlled by urb->lock ... changes on
	 * i/o completion (normal or fault) or unlinking.
	 */

	// FIXME:  verify that quiescing hc works right (RH cleans up)

	spin_lock_irqsave (&hcd_data_lock, flags);
	ep = (usb_pipein(urb->pipe) ? urb->dev->ep_in : urb->dev->ep_out)
			[usb_pipeendpoint(urb->pipe)];
	if (unlikely (!ep))
		status = -ENOENT;
	else if (unlikely (urb->reject))
		status = -EPERM;
	else switch (hcd->state) {
	case HC_STATE_RUNNING:
	case HC_STATE_RESUMING:
doit:
		usb_get_dev (urb->dev);
		list_add_tail (&urb->urb_list, &ep->urb_list);
		status = 0;
		break;
	case HC_STATE_SUSPENDED:
		/* HC upstream links (register access, wakeup signaling) can work
		 * even when the downstream links (and DMA etc) are quiesced; let
		 * usbcore talk to the root hub.
		 */
		if (hcd->self.controller->power.power_state.event == PM_EVENT_ON
				&& urb->dev->parent == NULL)
			goto doit;
		/* FALL THROUGH */
	default:
		status = -ESHUTDOWN;
		break;
	}
	spin_unlock_irqrestore (&hcd_data_lock, flags);
	if (status) {
		INIT_LIST_HEAD (&urb->urb_list);
		usbmon_urb_submit_error(&hcd->self, urb, status);
		return status;
	}

	/* increment urb's reference count as part of giving it to the HCD
	 * (which now controls it).  HCD guarantees that it either returns
	 * an error or calls giveback(), but not both.
	 */
	urb = usb_get_urb (urb);
	atomic_inc (&urb->use_count);

	if (urb->dev == hcd->self.root_hub) {
		/* NOTE:  requirement on hub callers (usbfs and the hub
		 * driver, for now) that URBs' urb->transfer_buffer be
		 * valid and usb_buffer_{sync,unmap}() not be needed, since
		 * they could clobber root hub response data.
		 */
		status = rh_urb_enqueue (hcd, urb);
		goto done;
	}

	/* lower level hcd code should use *_dma exclusively,
	 * unless it uses pio or talks to another transport.
	 */
	if (hcd->self.controller->dma_mask) {
		if (usb_pipecontrol (urb->pipe)
			&& !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
			urb->setup_dma = dma_map_single (
					hcd->self.controller,
					urb->setup_packet,
					sizeof (struct usb_ctrlrequest),
					DMA_TO_DEVICE);
		if (urb->transfer_buffer_length != 0
			&& !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP))
			urb->transfer_dma = dma_map_single (
					hcd->self.controller,
					urb->transfer_buffer,
					urb->transfer_buffer_length,
					usb_pipein (urb->pipe)
					    ? DMA_FROM_DEVICE
					    : DMA_TO_DEVICE);
	}

	status = hcd->driver->urb_enqueue (hcd, ep, urb, mem_flags);
done:
	if (unlikely (status)) {
		urb_unlink (urb);
		atomic_dec (&urb->use_count);
		if (urb->reject)
			wake_up (&usb_kill_urb_queue);
		usb_put_urb (urb);
		usbmon_urb_submit_error(&hcd->self, urb, status);
	}
	return status;
}

/*-------------------------------------------------------------------------*/

/* called in any context */
static int hcd_get_frame_number (struct usb_device *udev)
{
	struct usb_hcd	*hcd = (struct usb_hcd *)udev->bus->hcpriv;
	if (!HC_IS_RUNNING (hcd->state))
		return -ESHUTDOWN;
	return hcd->driver->get_frame_number (hcd);
}

/*-------------------------------------------------------------------------*/

/* this makes the hcd giveback() the urb more quickly, by kicking it
 * off hardware queues (which may take a while) and returning it as
 * soon as practical.  we've already set up the urb's return status,
 * but we can't know if the callback completed already.
 */
static int
unlink1 (struct usb_hcd *hcd, struct urb *urb)
{
	int		value;

	if (urb->dev == hcd->self.root_hub)
		value = usb_rh_urb_dequeue (hcd, urb);
	else {

		/* The only reason an HCD might fail this call is if
		 * it has not yet fully queued the urb to begin with.
		 * Such failures should be harmless. */
		value = hcd->driver->urb_dequeue (hcd, urb);
	}

	if (value != 0)
		dev_dbg (hcd->self.controller, "dequeue %p --> %d\n",
				urb, value);
	return value;
}

/*
 * called in any context
 *
 * caller guarantees urb won't be recycled till both unlink()
 * and the urb's completion function return
 */
static int hcd_unlink_urb (struct urb *urb, int status)
{
	struct usb_host_endpoint	*ep;
	struct usb_hcd			*hcd = NULL;
	struct device			*sys = NULL;
	unsigned long			flags;
	struct list_head		*tmp;
	int				retval;

	if (!urb)
		return -EINVAL;
	if (!urb->dev || !urb->dev->bus)
		return -ENODEV;
	ep = (usb_pipein(urb->pipe) ? urb->dev->ep_in : urb->dev->ep_out)
			[usb_pipeendpoint(urb->pipe)];
	if (!ep)
		return -ENODEV;

	/*
	 * we contend for urb->status with the hcd core,
	 * which changes it while returning the urb.
	 *
	 * Caller guaranteed that the urb pointer hasn't been freed, and
	 * that it was submitted.  But as a rule it can't know whether or
	 * not it's already been unlinked ... so we respect the reversed
	 * lock sequence needed for the usb_hcd_giveback_urb() code paths
	 * (urb lock, then hcd_data_lock) in case some other CPU is now
	 * unlinking it.
	 */
	spin_lock_irqsave (&urb->lock, flags);
	spin_lock (&hcd_data_lock);

	sys = &urb->dev->dev;
	hcd = urb->dev->bus->hcpriv;
	if (hcd == NULL) {
		retval = -ENODEV;
		goto done;
	}

	/* insist the urb is still queued */
	list_for_each(tmp, &ep->urb_list) {
		if (tmp == &urb->urb_list)
			break;
	}
	if (tmp != &urb->urb_list) {
		retval = -EIDRM;
		goto done;
	}

	/* Any status except -EINPROGRESS means something already started to
	 * unlink this URB from the hardware.  So there's no more work to do.
	 */
	if (urb->status != -EINPROGRESS) {
		retval = -EBUSY;
		goto done;
	}

	/* IRQ setup can easily be broken so that USB controllers
	 * never get completion IRQs ... maybe even the ones we need to
	 * finish unlinking the initial failed usb_set_address()
	 * or device descriptor fetch.
	 */
	if (!test_bit(HCD_FLAG_SAW_IRQ, &hcd->flags)
	    && hcd->self.root_hub != urb->dev) {
		dev_warn (hcd->self.controller, "Unlink after no-IRQ?  "
			"Controller is probably using the wrong IRQ."
			"\n");
		set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
	}

	urb->status = status;

	spin_unlock (&hcd_data_lock);
	spin_unlock_irqrestore (&urb->lock, flags);

	retval = unlink1 (hcd, urb);
	if (retval == 0)
		retval = -EINPROGRESS;
	return retval;

done:
	spin_unlock (&hcd_data_lock);
	spin_unlock_irqrestore (&urb->lock, flags);
	if (retval != -EIDRM && sys && sys->driver)
		dev_dbg (sys, "hcd_unlink_urb %p fail %d\n", urb, retval);
	return retval;
}

/*-------------------------------------------------------------------------*/

/* disables the endpoint: cancels any pending urbs, then synchronizes with
 * the hcd to make sure all endpoint state is gone from hardware. use for
 * set_configuration, set_interface, driver removal, physical disconnect.
 *
 * example:  a qh stored in ep->hcpriv, holding state related to endpoint
 * type, maxpacket size, toggle, halt status, and scheduling.
 */
static void
hcd_endpoint_disable (struct usb_device *udev, struct usb_host_endpoint *ep)
{
	struct usb_hcd		*hcd;
	struct urb		*urb;

	hcd = udev->bus->hcpriv;

	WARN_ON (!HC_IS_RUNNING (hcd->state) && hcd->state != HC_STATE_HALT &&
			udev->state != USB_STATE_NOTATTACHED);

	local_irq_disable ();

	/* FIXME move most of this into message.c as part of its
	 * endpoint disable logic
	 */

	/* ep is already gone from udev->ep_{in,out}[]; no more submits */
rescan:
	spin_lock (&hcd_data_lock);
	list_for_each_entry (urb, &ep->urb_list, urb_list) {
		int	tmp;

		/* another cpu may be in hcd, spinning on hcd_data_lock
		 * to giveback() this urb.  the races here should be
		 * small, but a full fix needs a new "can't submit"
		 * urb state.
		 * FIXME urb->reject should allow that...
		 */
		if (urb->status != -EINPROGRESS)
			continue;
		usb_get_urb (urb);
		spin_unlock (&hcd_data_lock);

		spin_lock (&urb->lock);
		tmp = urb->status;
		if (tmp == -EINPROGRESS)
			urb->status = -ESHUTDOWN;
		spin_unlock (&urb->lock);

		/* kick hcd unless it's already returning this */
		if (tmp == -EINPROGRESS) {
			tmp = urb->pipe;
			unlink1 (hcd, urb);
			dev_dbg (hcd->self.controller,
				"shutdown urb %p pipe %08x ep%d%s%s\n",
				urb, tmp, usb_pipeendpoint (tmp),
				(tmp & USB_DIR_IN) ? "in" : "out",
				({ char *s; \
				 switch (usb_pipetype (tmp)) { \
				 case PIPE_CONTROL:	s = ""; break; \
				 case PIPE_BULK:	s = "-bulk"; break; \
				 case PIPE_INTERRUPT:	s = "-intr"; break; \
				 default: 		s = "-iso"; break; \
				}; s;}));
		}
		usb_put_urb (urb);

		/* list contents may have changed */
		goto rescan;
	}
	spin_unlock (&hcd_data_lock);
	local_irq_enable ();

	/* synchronize with the hardware, so old configuration state
	 * clears out immediately (and will be freed).
	 */
	might_sleep ();
	if (hcd->driver->endpoint_disable)
		hcd->driver->endpoint_disable (hcd, ep);
}

/*-------------------------------------------------------------------------*/

#ifdef	CONFIG_PM

int hcd_bus_suspend (struct usb_bus *bus)
{
	struct usb_hcd		*hcd;
	int			status;

	hcd = container_of (bus, struct usb_hcd, self);
	if (!hcd->driver->bus_suspend)
		return -ENOENT;
	hcd->state = HC_STATE_QUIESCING;
	status = hcd->driver->bus_suspend (hcd);
	if (status == 0)
		hcd->state = HC_STATE_SUSPENDED;
	else
		dev_dbg(&bus->root_hub->dev, "%s fail, err %d\n",
				"suspend", status);
	return status;
}

int hcd_bus_resume (struct usb_bus *bus)
{
	struct usb_hcd		*hcd;
	int			status;

	hcd = container_of (bus, struct usb_hcd, self);
	if (!hcd->driver->bus_resume)
		return -ENOENT;
	if (hcd->state == HC_STATE_RUNNING)
		return 0;
	hcd->state = HC_STATE_RESUMING;
	status = hcd->driver->bus_resume (hcd);
	if (status == 0)
		hcd->state = HC_STATE_RUNNING;
	else {