sta_tx.c

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/*
 * 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;
    u16 pkt_type, pkt_offset;

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

    pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;

    /* 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 */
    pkt_offset = sizeof(struct txpd) + pad;
    if (pkt_type == PKT_TYPE_MGMT) {
        /* Set the packet type and add header for management frame */
        local_tx_pd->tx_pkt_type = cpu_to_le16(pkt_type);
        pkt_offset += MWIFIEX_MGMT_FRAME_HEADER_SIZE;
    }

    local_tx_pd->tx_pkt_offset = cpu_to_le16(pkt_offset);

    /* 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_num = priv->bss_num;
    tx_info->bss_type = priv->bss_type;
    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;

    if (adapter->iface_type == MWIFIEX_USB) {
        ret = adapter->if_ops.host_to_card(adapter, MWIFIEX_USB_EP_DATA,
                           skb, NULL);
    } else {
        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;
}