linux/drivers/net/wireless/mwifiex/txrx.c

/*
 * Marvell Wireless LAN device driver: generic TX/RX data handling
 *
 * Copyright (C) 2011, Marvell International Ltd.
 *
 * This software file (the "File") is distributed by Marvell International
 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available by writing to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
 * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 */

#include "decl.h"
#include "ioctl.h"
#include "util.h"
#include "fw.h"
#include "main.h"
#include "wmm.h"

/*
 * This function processes the received buffer.
 *
 * Main responsibility of this function is to parse the RxPD to
 * identify the correct interface this packet is headed for and
 * forwarding it to the associated handling function, where the
 * packet will be further processed and sent to kernel/upper layer
 * if required.
 */
int mwifiex_handle_rx_packet(struct mwifiex_adapter *adapter,
			     struct sk_buff *skb)
{
	struct mwifiex_private *priv =
		mwifiex_get_priv(adapter, MWIFIEX_BSS_ROLE_ANY);
	struct rxpd *local_rx_pd;
	struct mwifiex_rxinfo *rx_info = MWIFIEX_SKB_RXCB(skb);

	local_rx_pd = (struct rxpd *) (skb->data);
	/* Get the BSS number from rxpd, get corresponding priv */
	priv = mwifiex_get_priv_by_id(adapter, local_rx_pd->bss_num &
				      BSS_NUM_MASK, local_rx_pd->bss_type);
	if (!priv)
		priv = mwifiex_get_priv(adapter, MWIFIEX_BSS_ROLE_ANY);

	rx_info->bss_index = priv->bss_index;

	return mwifiex_process_sta_rx_packet(adapter, skb);
}
EXPORT_SYMBOL_GPL(mwifiex_handle_rx_packet);

/*
 * This function sends a packet to device.
 *
 * It processes the packet to add the TxPD, checks condition and
 * sends the processed packet to firmware for transmission.
 *
 * On successful completion, the function calls the completion callback
 * and logs the time.
 */
int mwifiex_process_tx(struct mwifiex_private *priv, struct sk_buff *skb,
		       struct mwifiex_tx_param *tx_param)
{
	int ret = -1;
	struct mwifiex_adapter *adapter = priv->adapter;
	u8 *head_ptr;
	struct txpd *local_tx_pd = NULL;

	head_ptr = mwifiex_process_sta_txpd(priv, skb);
	if (head_ptr) {
		if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA)
			local_tx_pd =
				(struct txpd *) (head_ptr + INTF_HEADER_LEN);

		ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_TYPE_DATA,
					     skb->data, skb->len, tx_param);
	}

	switch (ret) {
	case -EBUSY:
		if ((GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA) &&
			(adapter->pps_uapsd_mode) &&
			(adapter->tx_lock_flag)) {
				priv->adapter->tx_lock_flag = false;
				local_tx_pd->flags = 0;
		}
		dev_dbg(adapter->dev, "data: -EBUSY is returned\n");
		break;
	case -1:
		adapter->data_sent = false;
		dev_err(adapter->dev, "mwifiex_write_data_async failed: 0x%X\n",
		       ret);
		adapter->dbg.num_tx_host_to_card_failure++;
		mwifiex_write_data_complete(adapter, skb, ret);
		break;
	case -EINPROGRESS:
		adapter->data_sent = false;
		break;
	case 0:
		mwifiex_write_data_complete(adapter, skb, ret);
		break;
	default:
		break;
	}

	return ret;
}

/*
 * Packet send completion callback handler.
 *
 * It either frees the buffer directly or forwards it to another
 * completion callback which checks conditions, updates statistics,
 * wakes up stalled traffic queue if required, and then frees the buffer.
 */
int mwifiex_write_data_complete(struct mwifiex_adapter *adapter,
				struct sk_buff *skb, int status)
{
	struct mwifiex_private *priv, *tpriv;
	struct mwifiex_txinfo *tx_info;
	int i;

	if (!skb)
		return 0;

	tx_info = MWIFIEX_SKB_TXCB(skb);
	priv = mwifiex_bss_index_to_priv(adapter, tx_info->bss_index);
	if (!priv)
		goto done;

	priv->netdev->trans_start = jiffies;
	if (!status) {
		priv->stats.tx_packets++;
		priv->stats.tx_bytes += skb->len;
	} else {
		priv->stats.tx_errors++;
	}

	if (atomic_dec_return(&adapter->tx_pending) >= LOW_TX_PENDING)
		goto done;

	for (i = 0; i < adapter->priv_num; i++) {

		tpriv = adapter->priv[i];

		if ((GET_BSS_ROLE(tpriv) == MWIFIEX_BSS_ROLE_STA)
				&& (tpriv->media_connected)) {
			if (netif_queue_stopped(tpriv->netdev))
				netif_wake_queue(tpriv->netdev);
		}
	}
done:
	dev_kfree_skb_any(skb);

	return 0;
}

/*
 * Packet receive completion callback handler.
 *
 * This function calls another completion callback handler which
 * updates the statistics, and optionally updates the parent buffer
 * use count before freeing the received packet.
 */
int mwifiex_recv_packet_complete(struct mwifiex_adapter *adapter,
				 struct sk_buff *skb, int status)
{
	struct mwifiex_rxinfo *rx_info = MWIFIEX_SKB_RXCB(skb);
	struct mwifiex_rxinfo *rx_info_parent;
	struct mwifiex_private *priv;
	struct sk_buff *skb_parent;
	unsigned long flags;

	priv = adapter->priv[rx_info->bss_index];

	if (priv && (status == -1))
		priv->stats.rx_dropped++;

	if (rx_info->parent) {
		skb_parent = rx_info->parent;
		rx_info_parent = MWIFIEX_SKB_RXCB(skb_parent);

		spin_lock_irqsave(&priv->rx_pkt_lock, flags);
		--rx_info_parent->use_count;

		if (!rx_info_parent->use_count) {
			spin_unlock_irqrestore(&priv->rx_pkt_lock, flags);
			dev_kfree_skb_any(skb_parent);
		} else {
			spin_unlock_irqrestore(&priv->rx_pkt_lock, flags);
		}
	} else {
		dev_kfree_skb_any(skb);
	}

	return 0;
}