/**
 * usb_serial_generic_write_start - kick off an URB write
 * @port:	Pointer to the &struct usb_serial_port data
 *
 * Returns zero on success, or a negative errno value
 */
static int usb_serial_generic_write_start(struct usb_serial_port *port)
{
	struct urb *urb;
	int count, result;
	unsigned long flags;
	int i;

	if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
		return 0;
retry:
	spin_lock_irqsave(&port->lock, flags);
	if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
		clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
		spin_unlock_irqrestore(&port->lock, flags);
		return 0;
	}
	i = (int)find_first_bit(&port->write_urbs_free,
						ARRAY_SIZE(port->write_urbs));
	spin_unlock_irqrestore(&port->lock, flags);

	urb = port->write_urbs[i];
	count = port->serial->type->prepare_write_buffer(port,
						urb->transfer_buffer,
						port->bulk_out_size);
	urb->transfer_buffer_length = count;
	usb_serial_debug_data(debug, &port->dev, __func__, count,
						urb->transfer_buffer);
	spin_lock_irqsave(&port->lock, flags);
	port->tx_bytes += count;
	spin_unlock_irqrestore(&port->lock, flags);

	clear_bit(i, &port->write_urbs_free);
	result = usb_submit_urb(urb, GFP_ATOMIC);
	if (result) {
		dev_err(&port->dev, "%s - error submitting urb: %d\n",
						__func__, result);
		set_bit(i, &port->write_urbs_free);
		spin_lock_irqsave(&port->lock, flags);
		port->tx_bytes -= count;
		spin_unlock_irqrestore(&port->lock, flags);

		clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
		return result;
	}

	/* Try sending off another urb, unless in irq context (in which case
	 * there will be no free urb). */
	if (!in_irq())
		goto retry;

	clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);

	return 0;
}

 /**
  * unlock_page - unlock a locked page
  * @page: the page
  *
  * Unlocks the page and wakes up sleepers in ___wait_on_page_locked().
  * Also wakes sleepers in wait_on_page_writeback() because the wakeup
  * mechanism between PageLocked pages and PageWriteback pages is shared.
  * But that's OK - sleepers in wait_on_page_writeback() just go back to sleep.
  *
  * The mb is necessary to enforce ordering between the clear_bit and the read
  * of the waitqueue (to avoid SMP races with a parallel wait_on_page_locked()).
  */
 void unlock_page(struct page *page)
 {
         VM_BUG_ON_PAGE(!PageLocked(page), page);
         clear_bit_unlock(PG_locked, &page->flags);
         smp_mb__after_atomic();
         wake_up_page(page, PG_locked);
 }

/**
 * i40e_ptp_tx_hwtstamp - Utility function which returns the Tx timestamp
 * @pf: Board private structure
 *
 * Read the value of the Tx timestamp from the registers, convert it into a
 * value consumable by the stack, and store that result into the shhwtstamps
 * struct before returning it up the stack.
 **/
void i40e_ptp_tx_hwtstamp(struct i40e_pf *pf)
{
	struct skb_shared_hwtstamps shhwtstamps;
	struct i40e_hw *hw = &pf->hw;
	u32 hi, lo;
	u64 ns;

	if (!(pf->flags & I40E_FLAG_PTP) || !pf->ptp_tx)
		return;

	/* don't attempt to timestamp if we don't have an skb */
	if (!pf->ptp_tx_skb)
		return;

	lo = rd32(hw, I40E_PRTTSYN_TXTIME_L);
	hi = rd32(hw, I40E_PRTTSYN_TXTIME_H);

	ns = (((u64)hi) << 32) | lo;

	i40e_ptp_convert_to_hwtstamp(&shhwtstamps, ns);
	skb_tstamp_tx(pf->ptp_tx_skb, &shhwtstamps);
	dev_kfree_skb_any(pf->ptp_tx_skb);
	pf->ptp_tx_skb = NULL;
	clear_bit_unlock(__I40E_PTP_TX_IN_PROGRESS, &pf->state);
}

static void put_tag(struct nullb_queue *nq, unsigned int tag)
{
	clear_bit_unlock(tag, nq->tag_map);

	if (waitqueue_active(&nq->wait))
		wake_up(&nq->wait);
}

static void escvp_get_rdlen_callback(struct urb *urb)
{
  __u16 *data;
  __u16 rdlen = 0x0000;
  int len;
  struct escvp_port *vport;
  struct device *dev = &urb->dev->dev;
  int status = urb->status;
  vport = urb->context;
  switch (status) {
    case 0:
      break;
    case -ECONNRESET:
    case -ENOENT:
    case -ESHUTDOWN:
      dev_dbg(dev, "%s - urb shutting down with status : %d\n", __func__, status);
      goto out;
    default:
      dev_dbg(dev, "%s - nonzero urb status received: %dn", __func__, status);
      goto out;
  }
  data = urb->transfer_buffer;
  rdlen = data[0];
  len = (int)rdlen;
out:
  clear_bit_unlock(ESCVP_FLAG_CTRL_BUSY, &vport->flags);
  if(rdlen != 0x0000){
    escvp_get_rd(vport,rdlen);
  }
}

/**
 * blk_queue_end_tag - end tag operations for a request
 * @q:  the request queue for the device
 * @rq: the request that has completed
 *
 *  Description:
 *    Typically called when end_that_request_first() returns %0, meaning
 *    all transfers have been done for a request. It's important to call
 *    this function before end_that_request_last(), as that will put the
 *    request back on the free list thus corrupting the internal tag list.
 *
 *  Notes:
 *   queue lock must be held.
 **/
void blk_queue_end_tag(struct request_queue *q, struct request *rq)
{
	struct blk_queue_tag *bqt = q->queue_tags;
	int tag = rq->tag;

	BUG_ON(tag == -1);

	if (unlikely(tag >= bqt->real_max_depth))
		/*
		 * This can happen after tag depth has been reduced.
		 * FIXME: how about a warning or info message here?
		 */
		return;

	list_del_init(&rq->queuelist);
	rq->cmd_flags &= ~REQ_QUEUED;
	rq->tag = -1;

	if (unlikely(bqt->tag_index[tag] == NULL))
		printk(KERN_ERR "%s: tag %d is missing\n",
		       __func__, tag);

	bqt->tag_index[tag] = NULL;

	if (unlikely(!test_bit(tag, bqt->tag_map))) {
		printk(KERN_ERR "%s: attempt to clear non-busy tag (%d)\n",
		       __func__, tag);
		return;
	}
	/*
	 * The tag_map bit acts as a lock for tag_index[bit], so we need
	 * unlock memory barrier semantics.
	 */
	clear_bit_unlock(tag, bqt->tag_map);
}

int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
	struct inode *inode = mapping->host;
	unsigned long *bitlock = &NFS_I(inode)->flags;
	struct nfs_pageio_descriptor pgio;
	int err;

	/* Stop dirtying of new pages while we sync */
	err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING,
			nfs_wait_bit_killable, TASK_KILLABLE);
	if (err)
		goto out_err;

	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);

	nfs_pageio_init_write(&pgio, inode, wb_priority(wbc));
	err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
	nfs_pageio_complete(&pgio);

	clear_bit_unlock(NFS_INO_FLUSHING, bitlock);
	smp_mb__after_clear_bit();
	wake_up_bit(bitlock, NFS_INO_FLUSHING);

	if (err < 0)
		goto out_err;
	err = pgio.pg_error;
	if (err < 0)
		goto out_err;
	return 0;
out_err:
	return err;
}

/**
 * i40e_ptp_tx_hang - Detect error case when Tx timestamp register is hung
 * @pf: The PF private data structure
 *
 * This watchdog task is run periodically to make sure that we clear the Tx
 * timestamp logic if we don't obtain a timestamp in a reasonable amount of
 * time. It is unexpected in the normal case but if it occurs it results in
 * permanently preventing timestamps of future packets.
 **/
void i40e_ptp_tx_hang(struct i40e_pf *pf)
{
	struct sk_buff *skb;

	if (!(pf->flags & I40E_FLAG_PTP) || !pf->ptp_tx)
		return;

	/* Nothing to do if we're not already waiting for a timestamp */
	if (!test_bit(__I40E_PTP_TX_IN_PROGRESS, pf->state))
		return;

	/* We already have a handler routine which is run when we are notified
	 * of a Tx timestamp in the hardware. If we don't get an interrupt
	 * within a second it is reasonable to assume that we never will.
	 */
	if (time_is_before_jiffies(pf->ptp_tx_start + HZ)) {
		skb = pf->ptp_tx_skb;
		pf->ptp_tx_skb = NULL;
		clear_bit_unlock(__I40E_PTP_TX_IN_PROGRESS, pf->state);

		/* Free the skb after we clear the bitlock */
		dev_kfree_skb_any(skb);
		pf->tx_hwtstamp_timeouts++;
	}
}

/**
 * igb_ptp_tx_work
 * @work: pointer to work struct
 *
 * This work function polls the TSYNCTXCTL valid bit to determine when a
 * timestamp has been taken for the current stored skb.
 **/
static void igb_ptp_tx_work(struct work_struct *work)
{
	struct igb_adapter *adapter = container_of(work, struct igb_adapter,
						   ptp_tx_work);
	struct e1000_hw *hw = &adapter->hw;
	u32 tsynctxctl;

	if (!adapter->ptp_tx_skb)
		return;

	if (time_is_before_jiffies(adapter->ptp_tx_start +
				   IGB_PTP_TX_TIMEOUT)) {
		dev_kfree_skb_any(adapter->ptp_tx_skb);
		adapter->ptp_tx_skb = NULL;
		clear_bit_unlock(__IGB_PTP_TX_IN_PROGRESS, &adapter->state);
		adapter->tx_hwtstamp_timeouts++;
		dev_warn(&adapter->pdev->dev, "clearing Tx timestamp hang\n");
		return;
	}

	tsynctxctl = rd32(E1000_TSYNCTXCTL);
	if (tsynctxctl & E1000_TSYNCTXCTL_VALID)
		igb_ptp_tx_hwtstamp(adapter);
	else
		/* reschedule to check later */
		schedule_work(&adapter->ptp_tx_work);
}

/**
 * igb_ptp_tx_hwtstamp - utility function which checks for TX time stamp
 * @adapter: Board private structure.
 *
 * If we were asked to do hardware stamping and such a time stamp is
 * available, then it must have been for this skb here because we only
 * allow only one such packet into the queue.
 **/
static void igb_ptp_tx_hwtstamp(struct igb_adapter *adapter)
{
	struct e1000_hw *hw = &adapter->hw;
	struct skb_shared_hwtstamps shhwtstamps;
	u64 regval;
	int adjust = 0;

	regval = rd32(E1000_TXSTMPL);
	regval |= (u64)rd32(E1000_TXSTMPH) << 32;

	igb_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval);
	/* adjust timestamp for the TX latency based on link speed */
	if (adapter->hw.mac.type == e1000_i210) {
		switch (adapter->link_speed) {
		case SPEED_10:
			adjust = IGB_I210_TX_LATENCY_10;
			break;
		case SPEED_100:
			adjust = IGB_I210_TX_LATENCY_100;
			break;
		case SPEED_1000:
			adjust = IGB_I210_TX_LATENCY_1000;
			break;
		}
	}

	shhwtstamps.hwtstamp = ktime_sub_ns(shhwtstamps.hwtstamp, adjust);

	skb_tstamp_tx(adapter->ptp_tx_skb, &shhwtstamps);
	dev_kfree_skb_any(adapter->ptp_tx_skb);
	adapter->ptp_tx_skb = NULL;
	clear_bit_unlock(__IGB_PTP_TX_IN_PROGRESS, &adapter->state);
}

/**
 * igb_ptp_stop - Disable PTP device and stop the overflow check.
 * @adapter: Board private structure.
 *
 * This function stops the PTP support and cancels the delayed work.
 **/
void igb_ptp_stop(struct igb_adapter *adapter)
{
	switch (adapter->hw.mac.type) {
	case e1000_82576:
	case e1000_82580:
	case e1000_i354:
	case e1000_i350:
		cancel_delayed_work_sync(&adapter->ptp_overflow_work);
		break;
	case e1000_i210:
	case e1000_i211:
		/* No delayed work to cancel. */
		break;
	default:
		return;
	}

	cancel_work_sync(&adapter->ptp_tx_work);
	if (adapter->ptp_tx_skb) {
		dev_kfree_skb_any(adapter->ptp_tx_skb);
		adapter->ptp_tx_skb = NULL;
		clear_bit_unlock(__IGB_PTP_TX_IN_PROGRESS, &adapter->state);
	}

	if (adapter->ptp_clock) {
		ptp_clock_unregister(adapter->ptp_clock);
		dev_info(&adapter->pdev->dev, "removed PHC on %s\n",
			 adapter->netdev->name);
		adapter->flags &= ~IGB_FLAG_PTP;
	}
}

/**
 * i40e_ptp_tx_hwtstamp - Utility function which returns the Tx timestamp
 * @pf: Board private structure
 *
 * Read the value of the Tx timestamp from the registers, convert it into a
 * value consumable by the stack, and store that result into the shhwtstamps
 * struct before returning it up the stack.
 **/
void i40e_ptp_tx_hwtstamp(struct i40e_pf *pf)
{
	struct skb_shared_hwtstamps shhwtstamps;
	struct sk_buff *skb = pf->ptp_tx_skb;
	struct i40e_hw *hw = &pf->hw;
	u32 hi, lo;
	u64 ns;

	if (!(pf->flags & I40E_FLAG_PTP) || !pf->ptp_tx)
		return;

	/* don't attempt to timestamp if we don't have an skb */
	if (!pf->ptp_tx_skb)
		return;

	lo = rd32(hw, I40E_PRTTSYN_TXTIME_L);
	hi = rd32(hw, I40E_PRTTSYN_TXTIME_H);

	ns = (((u64)hi) << 32) | lo;
	i40e_ptp_convert_to_hwtstamp(&shhwtstamps, ns);

	/* Clear the bit lock as soon as possible after reading the register,
	 * and prior to notifying the stack via skb_tstamp_tx(). Otherwise
	 * applications might wake up and attempt to request another transmit
	 * timestamp prior to the bit lock being cleared.
	 */
	pf->ptp_tx_skb = NULL;
	clear_bit_unlock(__I40E_PTP_TX_IN_PROGRESS, pf->state);

	/* Notify the stack and free the skb after we've unlocked */
	skb_tstamp_tx(skb, &shhwtstamps);
	dev_kfree_skb_any(skb);
}

/**
 * blk_queue_end_tag - end tag operations for a request
 * @q:  the request queue for the device
 * @rq: the request that has completed
 *
 *  Description:
 *    Typically called when end_that_request_first() returns %0, meaning
 *    all transfers have been done for a request. It's important to call
 *    this function before end_that_request_last(), as that will put the
 *    request back on the free list thus corrupting the internal tag list.
 *
 *  Notes:
 *   queue lock must be held.
 **/
void blk_queue_end_tag(struct request_queue *q, struct request *rq)
{
	struct blk_queue_tag *bqt = q->queue_tags;
	unsigned tag = rq->tag; /* negative tags invalid */

	BUG_ON(tag >= bqt->real_max_depth);

	list_del_init(&rq->queuelist);
	rq->cmd_flags &= ~REQ_QUEUED;
	rq->tag = -1;

	if (unlikely(bqt->tag_index[tag] == NULL))
		printk(KERN_ERR "%s: tag %d is missing\n",
		       __func__, tag);

	bqt->tag_index[tag] = NULL;

	if (unlikely(!test_bit(tag, bqt->tag_map))) {
		printk(KERN_ERR "%s: attempt to clear non-busy tag (%d)\n",
		       __func__, tag);
		return;
	}
	/*
	 * The tag_map bit acts as a lock for tag_index[bit], so we need
	 * unlock memory barrier semantics.
	 */
	clear_bit_unlock(tag, bqt->tag_map);
}

int gfar_set_features(struct net_device *dev, netdev_features_t features)
{
	netdev_features_t changed = dev->features ^ features;
	struct gfar_private *priv = netdev_priv(dev);
	int err = 0;

	if (!(changed & (NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX |
			 NETIF_F_RXCSUM)))
		return 0;

	while (test_and_set_bit_lock(GFAR_RESETTING, &priv->state))
		cpu_relax();

	dev->features = features;

	if (dev->flags & IFF_UP) {
		/* Now we take down the rings to rebuild them */
		stop_gfar(dev);
		err = startup_gfar(dev);
	} else {
		gfar_mac_reset(priv);
	}

	clear_bit_unlock(GFAR_RESETTING, &priv->state);

	return err;
}

/**
 * usb_serial_generic_write_start - start writing buffered data
 * @port: usb-serial port
 * @mem_flags: flags to use for memory allocations
 *
 * Serialised using USB_SERIAL_WRITE_BUSY flag.
 *
 * Return: Zero on success or if busy, otherwise a negative errno value.
 */
int usb_serial_generic_write_start(struct usb_serial_port *port,
							gfp_t mem_flags)
{
	struct urb *urb;
	int count, result;
	unsigned long flags;
	int i;

	if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
		return 0;
retry:
	spin_lock_irqsave(&port->lock, flags);
	if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
		clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
		spin_unlock_irqrestore(&port->lock, flags);
		return 0;
	}
	i = (int)find_first_bit(&port->write_urbs_free,
						ARRAY_SIZE(port->write_urbs));
	spin_unlock_irqrestore(&port->lock, flags);

	urb = port->write_urbs[i];
	count = port->serial->type->prepare_write_buffer(port,
						urb->transfer_buffer,
						port->bulk_out_size);
	urb->transfer_buffer_length = count;
	usb_serial_debug_data(&port->dev, __func__, count, urb->transfer_buffer);
	spin_lock_irqsave(&port->lock, flags);
	port->tx_bytes += count;
	spin_unlock_irqrestore(&port->lock, flags);

	clear_bit(i, &port->write_urbs_free);
	result = usb_submit_urb(urb, mem_flags);
	if (result) {
		dev_err_console(port, "%s - error submitting urb: %d\n",
						__func__, result);
		set_bit(i, &port->write_urbs_free);
		spin_lock_irqsave(&port->lock, flags);
		port->tx_bytes -= count;
		spin_unlock_irqrestore(&port->lock, flags);

		clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
		return result;
	}

	goto retry;	/* try sending off another urb */
}

int
release_pmu(struct platform_device *pdev)
{
	if (WARN_ON(pdev != pmu_devices[pdev->id]))
		return -EINVAL;
	clear_bit_unlock(pdev->id, &pmu_lock);
	return 0;
}

static inline void ide_unlock_host(struct ide_host *host)
{
	if (host->host_flags & IDE_HFLAG_SERIALIZE) {
		/* for atari only */
		ide_release_lock();
		clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
	}
}

int
release_pmu(enum arm_pmu_type type)
{
	if (WARN_ON(!pmu_devices[type]))
		return -EINVAL;
	clear_bit_unlock(type, &pmu_lock);
	return 0;
}

static void gfs2_clear_glop_pending(struct gfs2_inode *ip)
{
	if (!ip)
		return;

	clear_bit_unlock(GIF_GLOP_PENDING, &ip->i_flags);
	wake_up_bit(&ip->i_flags, GIF_GLOP_PENDING);
}

static bool afs_vl_probe_done(struct afs_vlserver *server)
{
	if (!atomic_dec_and_test(&server->probe_outstanding))
		return false;

	wake_up_var(&server->probe_outstanding);
	clear_bit_unlock(AFS_VLSERVER_FL_PROBING, &server->flags);
	wake_up_bit(&server->flags, AFS_VLSERVER_FL_PROBING);
	return true;
}