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

/*
 * Marvell Wireless LAN device driver: station TX 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 fills the TxPD for tx packets.
 *
 * The Tx buffer received by this function should already have the
 * header space allocated for TxPD.
 *
 * This function inserts the TxPD in between interface header and actual
 * data and adjusts the buffer pointers accordingly.
 *
 * The following TxPD fields are set by this function, as required -
 *      - BSS number
 *      - Tx packet length and offset
 *      - Priority
 *      - Packet delay
 *      - Priority specific Tx control
 *      - Flags
 */
void *mwifiex_process_sta_txpd(struct mwifiex_private *priv,
				struct sk_buff *skb)
{
	struct mwifiex_adapter *adapter = priv->adapter;
	struct txpd *local_tx_pd;
	struct mwifiex_txinfo *tx_info = MWIFIEX_SKB_TXCB(skb);
	u8 pad;

	if (!skb->len) {
		dev_err(adapter->dev, "Tx: bad packet length: %d\n",
		       skb->len);
		tx_info->status_code = -1;
		return skb->data;
	}

	/* If skb->data is not aligned; add padding */
	pad = (4 - (((void *)skb->data - NULL) & 0x3)) % 4;

	BUG_ON(skb_headroom(skb) < (sizeof(*local_tx_pd) + INTF_HEADER_LEN
								+ pad));
	skb_push(skb, sizeof(*local_tx_pd) + pad);

	local_tx_pd = (struct txpd *) skb->data;
	memset(local_tx_pd, 0, sizeof(struct txpd));
	local_tx_pd->bss_num = priv->bss_num;
	local_tx_pd->bss_type = priv->bss_type;
	local_tx_pd->tx_pkt_length = cpu_to_le16((u16) (skb->len -
						(sizeof(struct txpd) + pad)));

	local_tx_pd->priority = (u8) skb->priority;
	local_tx_pd->pkt_delay_2ms =
		mwifiex_wmm_compute_drv_pkt_delay(priv, skb);

	if (local_tx_pd->priority <
	    ARRAY_SIZE(priv->wmm.user_pri_pkt_tx_ctrl))
		/*
		 * Set the priority specific tx_control field, setting of 0 will
		 *   cause the default value to be used later in this function
		 */
		local_tx_pd->tx_control =
			cpu_to_le32(priv->wmm.user_pri_pkt_tx_ctrl[local_tx_pd->
							 priority]);

	if (adapter->pps_uapsd_mode) {
		if (mwifiex_check_last_packet_indication(priv)) {
			adapter->tx_lock_flag = true;
			local_tx_pd->flags =
				MWIFIEX_TxPD_POWER_MGMT_LAST_PACKET;
		}
	}

	/* Offset of actual data */
	local_tx_pd->tx_pkt_offset = cpu_to_le16(sizeof(struct txpd) + pad);

	/* make space for INTF_HEADER_LEN */
	skb_push(skb, INTF_HEADER_LEN);

	if (!local_tx_pd->tx_control)
		/* TxCtrl set by user or default */
		local_tx_pd->tx_control = cpu_to_le32(priv->pkt_tx_ctrl);

	return skb->data;
}

/*
 * This function tells firmware to send a NULL data packet.
 *
 * The function creates a NULL data packet with TxPD and sends to the
 * firmware for transmission, with highest priority setting.
 */
int mwifiex_send_null_packet(struct mwifiex_private *priv, u8 flags)
{
	struct mwifiex_adapter *adapter = priv->adapter;
	struct txpd *local_tx_pd;
/* sizeof(struct txpd) + Interface specific header */
#define NULL_PACKET_HDR 64
	u32 data_len = NULL_PACKET_HDR;
	struct sk_buff *skb;
	int ret;
	struct mwifiex_txinfo *tx_info = NULL;

	if (adapter->surprise_removed)
		return -1;

	if (!priv->media_connected)
		return -1;

	if (adapter->data_sent)
		return -1;

	skb = dev_alloc_skb(data_len);
	if (!skb)
		return -1;

	tx_info = MWIFIEX_SKB_TXCB(skb);
	tx_info->bss_index = priv->bss_index;
	skb_reserve(skb, sizeof(struct txpd) + INTF_HEADER_LEN);
	skb_push(skb, sizeof(struct txpd));

	local_tx_pd = (struct txpd *) skb->data;
	local_tx_pd->tx_control = cpu_to_le32(priv->pkt_tx_ctrl);
	local_tx_pd->flags = flags;
	local_tx_pd->priority = WMM_HIGHEST_PRIORITY;
	local_tx_pd->tx_pkt_offset = cpu_to_le16(sizeof(struct txpd));
	local_tx_pd->bss_num = priv->bss_num;
	local_tx_pd->bss_type = priv->bss_type;

	skb_push(skb, INTF_HEADER_LEN);

	ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_TYPE_DATA,
					   skb, NULL);
	switch (ret) {
	case -EBUSY:
		adapter->data_sent = true;
		/* Fall through FAILURE handling */
	case -1:
		dev_kfree_skb_any(skb);
		dev_err(adapter->dev, "%s: host_to_card failed: ret=%d\n",
						__func__, ret);
		adapter->dbg.num_tx_host_to_card_failure++;
		break;
	case 0:
		dev_kfree_skb_any(skb);
		dev_dbg(adapter->dev, "data: %s: host_to_card succeeded\n",
						__func__);
		adapter->tx_lock_flag = true;
		break;
	case -EINPROGRESS:
		break;
	default:
		break;
	}

	return ret;
}

/*
 * This function checks if we need to send last packet indication.
 */
u8
mwifiex_check_last_packet_indication(struct mwifiex_private *priv)
{
	struct mwifiex_adapter *adapter = priv->adapter;
	u8 ret = false;

	if (!adapter->sleep_period.period)
		return ret;
	if (mwifiex_wmm_lists_empty(adapter))
			ret = true;

	if (ret && !adapter->cmd_sent && !adapter->curr_cmd
	    && !is_command_pending(adapter)) {
		adapter->delay_null_pkt = false;
		ret = true;
	} else {
		ret = false;
		adapter->delay_null_pkt = true;
	}
	return ret;
}