iwlagn: reduce redundant parameter definitions

[deliverable/linux.git] / drivers / net / wireless / iwlwifi / iwl-agn-tx.c

/******************************************************************************
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2010 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
 * USA
 *
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * Contact Information:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>

#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-sta.h"
#include "iwl-io.h"
#include "iwl-helpers.h"
#include "iwl-agn-hw.h"
#include "iwl-agn.h"

/*
 * mac80211 queues, ACs, hardware queues, FIFOs.
 *
 * Cf. http://wireless.kernel.org/en/developers/Documentation/mac80211/queues
 *
 * Mac80211 uses the following numbers, which we get as from it
 * by way of skb_get_queue_mapping(skb):
 *
 *      VO      0
 *      VI      1
 *      BE      2
 *      BK      3
 *
 *
 * Regular (not A-MPDU) frames are put into hardware queues corresponding
 * to the FIFOs, see comments in iwl-prph.h. Aggregated frames get their
 * own queue per aggregation session (RA/TID combination), such queues are
 * set up to map into FIFOs too, for which we need an AC->FIFO mapping. In
 * order to map frames to the right queue, we also need an AC->hw queue
 * mapping. This is implemented here.
 *
 * Due to the way hw queues are set up (by the hw specific modules like
 * iwl-4965.c, iwl-5000.c etc.), the AC->hw queue mapping is the identity
 * mapping.
 */

static const u8 tid_to_ac[] = {
        /* this matches the mac80211 numbers */
        2, 3, 3, 2, 1, 1, 0, 0
};

static inline int get_ac_from_tid(u16 tid)
{
        if (likely(tid < ARRAY_SIZE(tid_to_ac)))
                return tid_to_ac[tid];

        /* no support for TIDs 8-15 yet */
        return -EINVAL;
}

static inline int get_fifo_from_tid(struct iwl_rxon_context *ctx, u16 tid)
{
        if (likely(tid < ARRAY_SIZE(tid_to_ac)))
                return ctx->ac_to_fifo[tid_to_ac[tid]];

        /* no support for TIDs 8-15 yet */
        return -EINVAL;
}

/**
 * iwlagn_txq_update_byte_cnt_tbl - Set up entry in Tx byte-count array
 */
void iwlagn_txq_update_byte_cnt_tbl(struct iwl_priv *priv,
                                            struct iwl_tx_queue *txq,
                                            u16 byte_cnt)
{
        struct iwlagn_scd_bc_tbl *scd_bc_tbl = priv->scd_bc_tbls.addr;
        int write_ptr = txq->q.write_ptr;
        int txq_id = txq->q.id;
        u8 sec_ctl = 0;
        u8 sta_id = 0;
        u16 len = byte_cnt + IWL_TX_CRC_SIZE + IWL_TX_DELIMITER_SIZE;
        __le16 bc_ent;

        WARN_ON(len > 0xFFF || write_ptr >= TFD_QUEUE_SIZE_MAX);

        if (txq_id != priv->cmd_queue) {
                sta_id = txq->cmd[txq->q.write_ptr]->cmd.tx.sta_id;
                sec_ctl = txq->cmd[txq->q.write_ptr]->cmd.tx.sec_ctl;

                switch (sec_ctl & TX_CMD_SEC_MSK) {
                case TX_CMD_SEC_CCM:
                        len += CCMP_MIC_LEN;
                        break;
                case TX_CMD_SEC_TKIP:
                        len += TKIP_ICV_LEN;
                        break;
                case TX_CMD_SEC_WEP:
                        len += WEP_IV_LEN + WEP_ICV_LEN;
                        break;
                }
        }

        bc_ent = cpu_to_le16((len & 0xFFF) | (sta_id << 12));

        scd_bc_tbl[txq_id].tfd_offset[write_ptr] = bc_ent;

        if (write_ptr < TFD_QUEUE_SIZE_BC_DUP)
                scd_bc_tbl[txq_id].
                        tfd_offset[TFD_QUEUE_SIZE_MAX + write_ptr] = bc_ent;
}

void iwlagn_txq_inval_byte_cnt_tbl(struct iwl_priv *priv,
                                           struct iwl_tx_queue *txq)
{
        struct iwlagn_scd_bc_tbl *scd_bc_tbl = priv->scd_bc_tbls.addr;
        int txq_id = txq->q.id;
        int read_ptr = txq->q.read_ptr;
        u8 sta_id = 0;
        __le16 bc_ent;

        WARN_ON(read_ptr >= TFD_QUEUE_SIZE_MAX);

        if (txq_id != priv->cmd_queue)
                sta_id = txq->cmd[read_ptr]->cmd.tx.sta_id;

        bc_ent = cpu_to_le16(1 | (sta_id << 12));
        scd_bc_tbl[txq_id].tfd_offset[read_ptr] = bc_ent;

        if (read_ptr < TFD_QUEUE_SIZE_BC_DUP)
                scd_bc_tbl[txq_id].
                        tfd_offset[TFD_QUEUE_SIZE_MAX + read_ptr] = bc_ent;
}

static int iwlagn_tx_queue_set_q2ratid(struct iwl_priv *priv, u16 ra_tid,
                                        u16 txq_id)
{
        u32 tbl_dw_addr;
        u32 tbl_dw;
        u16 scd_q2ratid;

        scd_q2ratid = ra_tid & IWL_SCD_QUEUE_RA_TID_MAP_RATID_MSK;

        tbl_dw_addr = priv->scd_base_addr +
                        IWLAGN_SCD_TRANSLATE_TBL_OFFSET_QUEUE(txq_id);

        tbl_dw = iwl_read_targ_mem(priv, tbl_dw_addr);

        if (txq_id & 0x1)
                tbl_dw = (scd_q2ratid << 16) | (tbl_dw & 0x0000FFFF);
        else
                tbl_dw = scd_q2ratid | (tbl_dw & 0xFFFF0000);

        iwl_write_targ_mem(priv, tbl_dw_addr, tbl_dw);

        return 0;
}

static void iwlagn_tx_queue_stop_scheduler(struct iwl_priv *priv, u16 txq_id)
{
        /* Simply stop the queue, but don't change any configuration;
         * the SCD_ACT_EN bit is the write-enable mask for the ACTIVE bit. */
        iwl_write_prph(priv,
                IWLAGN_SCD_QUEUE_STATUS_BITS(txq_id),
                (0 << IWLAGN_SCD_QUEUE_STTS_REG_POS_ACTIVE)|
                (1 << IWLAGN_SCD_QUEUE_STTS_REG_POS_SCD_ACT_EN));
}

void iwlagn_set_wr_ptrs(struct iwl_priv *priv,
                                int txq_id, u32 index)
{
        iwl_write_direct32(priv, HBUS_TARG_WRPTR,
                        (index & 0xff) | (txq_id << 8));
        iwl_write_prph(priv, IWLAGN_SCD_QUEUE_RDPTR(txq_id), index);
}

void iwlagn_tx_queue_set_status(struct iwl_priv *priv,
                                        struct iwl_tx_queue *txq,
                                        int tx_fifo_id, int scd_retry)
{
        int txq_id = txq->q.id;
        int active = test_bit(txq_id, &priv->txq_ctx_active_msk) ? 1 : 0;

        iwl_write_prph(priv, IWLAGN_SCD_QUEUE_STATUS_BITS(txq_id),
                        (active << IWLAGN_SCD_QUEUE_STTS_REG_POS_ACTIVE) |
                        (tx_fifo_id << IWLAGN_SCD_QUEUE_STTS_REG_POS_TXF) |
                        (1 << IWLAGN_SCD_QUEUE_STTS_REG_POS_WSL) |
                        IWLAGN_SCD_QUEUE_STTS_REG_MSK);

        txq->sched_retry = scd_retry;

        IWL_DEBUG_INFO(priv, "%s %s Queue %d on FIFO %d\n",
                       active ? "Activate" : "Deactivate",
                       scd_retry ? "BA" : "AC/CMD", txq_id, tx_fifo_id);
}

int iwlagn_txq_agg_enable(struct iwl_priv *priv, int txq_id,
                          int tx_fifo, int sta_id, int tid, u16 ssn_idx)
{
        unsigned long flags;
        u16 ra_tid;
        int ret;

        if ((IWLAGN_FIRST_AMPDU_QUEUE > txq_id) ||
            (IWLAGN_FIRST_AMPDU_QUEUE +
                priv->cfg->base_params->num_of_ampdu_queues <= txq_id)) {
                IWL_WARN(priv,
                        "queue number out of range: %d, must be %d to %d\n",
                        txq_id, IWLAGN_FIRST_AMPDU_QUEUE,
                        IWLAGN_FIRST_AMPDU_QUEUE +
                        priv->cfg->base_params->num_of_ampdu_queues - 1);
                return -EINVAL;
        }

        ra_tid = BUILD_RAxTID(sta_id, tid);

        /* Modify device's station table to Tx this TID */
        ret = iwl_sta_tx_modify_enable_tid(priv, sta_id, tid);
        if (ret)
                return ret;

        spin_lock_irqsave(&priv->lock, flags);

        /* Stop this Tx queue before configuring it */
        iwlagn_tx_queue_stop_scheduler(priv, txq_id);

        /* Map receiver-address / traffic-ID to this queue */
        iwlagn_tx_queue_set_q2ratid(priv, ra_tid, txq_id);

        /* Set this queue as a chain-building queue */
        iwl_set_bits_prph(priv, IWLAGN_SCD_QUEUECHAIN_SEL, (1<<txq_id));

        /* enable aggregations for the queue */
        iwl_set_bits_prph(priv, IWLAGN_SCD_AGGR_SEL, (1<<txq_id));

        /* Place first TFD at index corresponding to start sequence number.
         * Assumes that ssn_idx is valid (!= 0xFFF) */
        priv->txq[txq_id].q.read_ptr = (ssn_idx & 0xff);
        priv->txq[txq_id].q.write_ptr = (ssn_idx & 0xff);
        iwlagn_set_wr_ptrs(priv, txq_id, ssn_idx);

        /* Set up Tx window size and frame limit for this queue */
        iwl_write_targ_mem(priv, priv->scd_base_addr +
                        IWLAGN_SCD_CONTEXT_QUEUE_OFFSET(txq_id) +
                        sizeof(u32),
                        ((SCD_WIN_SIZE <<
                        IWLAGN_SCD_QUEUE_CTX_REG2_WIN_SIZE_POS) &
                        IWLAGN_SCD_QUEUE_CTX_REG2_WIN_SIZE_MSK) |
                        ((SCD_FRAME_LIMIT <<
                        IWLAGN_SCD_QUEUE_CTX_REG2_FRAME_LIMIT_POS) &
                        IWLAGN_SCD_QUEUE_CTX_REG2_FRAME_LIMIT_MSK));

        iwl_set_bits_prph(priv, IWLAGN_SCD_INTERRUPT_MASK, (1 << txq_id));

        /* Set up Status area in SRAM, map to Tx DMA/FIFO, activate the queue */
        iwlagn_tx_queue_set_status(priv, &priv->txq[txq_id], tx_fifo, 1);

        spin_unlock_irqrestore(&priv->lock, flags);

        return 0;
}

int iwlagn_txq_agg_disable(struct iwl_priv *priv, u16 txq_id,
                           u16 ssn_idx, u8 tx_fifo)
{
        if ((IWLAGN_FIRST_AMPDU_QUEUE > txq_id) ||
            (IWLAGN_FIRST_AMPDU_QUEUE +
                priv->cfg->base_params->num_of_ampdu_queues <= txq_id)) {
                IWL_ERR(priv,
                        "queue number out of range: %d, must be %d to %d\n",
                        txq_id, IWLAGN_FIRST_AMPDU_QUEUE,
                        IWLAGN_FIRST_AMPDU_QUEUE +
                        priv->cfg->base_params->num_of_ampdu_queues - 1);
                return -EINVAL;
        }

        iwlagn_tx_queue_stop_scheduler(priv, txq_id);

        iwl_clear_bits_prph(priv, IWLAGN_SCD_AGGR_SEL, (1 << txq_id));

        priv->txq[txq_id].q.read_ptr = (ssn_idx & 0xff);
        priv->txq[txq_id].q.write_ptr = (ssn_idx & 0xff);
        /* supposes that ssn_idx is valid (!= 0xFFF) */
        iwlagn_set_wr_ptrs(priv, txq_id, ssn_idx);

        iwl_clear_bits_prph(priv, IWLAGN_SCD_INTERRUPT_MASK, (1 << txq_id));
        iwl_txq_ctx_deactivate(priv, txq_id);
        iwlagn_tx_queue_set_status(priv, &priv->txq[txq_id], tx_fifo, 0);

        return 0;
}

/*
 * Activate/Deactivate Tx DMA/FIFO channels according tx fifos mask
 * must be called under priv->lock and mac access
 */
void iwlagn_txq_set_sched(struct iwl_priv *priv, u32 mask)
{
        iwl_write_prph(priv, IWLAGN_SCD_TXFACT, mask);
}

/*
 * handle build REPLY_TX command notification.
 */
static void iwlagn_tx_cmd_build_basic(struct iwl_priv *priv,
                                        struct sk_buff *skb,
                                        struct iwl_tx_cmd *tx_cmd,
                                        struct ieee80211_tx_info *info,
                                        struct ieee80211_hdr *hdr,
                                        u8 std_id)
{
        __le16 fc = hdr->frame_control;
        __le32 tx_flags = tx_cmd->tx_flags;

        tx_cmd->stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
        if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
                tx_flags |= TX_CMD_FLG_ACK_MSK;
                if (ieee80211_is_mgmt(fc))
                        tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
                if (ieee80211_is_probe_resp(fc) &&
                    !(le16_to_cpu(hdr->seq_ctrl) & 0xf))
                        tx_flags |= TX_CMD_FLG_TSF_MSK;
        } else {
                tx_flags &= (~TX_CMD_FLG_ACK_MSK);
                tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
        }

        if (ieee80211_is_back_req(fc))
                tx_flags |= TX_CMD_FLG_ACK_MSK | TX_CMD_FLG_IMM_BA_RSP_MASK;
        else if (info->band == IEEE80211_BAND_2GHZ &&
                 priv->cfg->bt_params &&
                 priv->cfg->bt_params->advanced_bt_coexist &&
                 (ieee80211_is_auth(fc) || ieee80211_is_assoc_req(fc) ||
                 ieee80211_is_reassoc_req(fc) ||
                 skb->protocol == cpu_to_be16(ETH_P_PAE)))
                tx_flags |= TX_CMD_FLG_IGNORE_BT;


        tx_cmd->sta_id = std_id;
        if (ieee80211_has_morefrags(fc))
                tx_flags |= TX_CMD_FLG_MORE_FRAG_MSK;

        if (ieee80211_is_data_qos(fc)) {
                u8 *qc = ieee80211_get_qos_ctl(hdr);
                tx_cmd->tid_tspec = qc[0] & 0xf;
                tx_flags &= ~TX_CMD_FLG_SEQ_CTL_MSK;
        } else {
                tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
        }

        priv->cfg->ops->utils->tx_cmd_protection(priv, info, fc, &tx_flags);

        tx_flags &= ~(TX_CMD_FLG_ANT_SEL_MSK);
        if (ieee80211_is_mgmt(fc)) {
                if (ieee80211_is_assoc_req(fc) || ieee80211_is_reassoc_req(fc))
                        tx_cmd->timeout.pm_frame_timeout = cpu_to_le16(3);
                else
                        tx_cmd->timeout.pm_frame_timeout = cpu_to_le16(2);
        } else {
                tx_cmd->timeout.pm_frame_timeout = 0;
        }

        tx_cmd->driver_txop = 0;
        tx_cmd->tx_flags = tx_flags;
        tx_cmd->next_frame_len = 0;
}

#define RTS_DFAULT_RETRY_LIMIT          60

static void iwlagn_tx_cmd_build_rate(struct iwl_priv *priv,
                              struct iwl_tx_cmd *tx_cmd,
                              struct ieee80211_tx_info *info,
                              __le16 fc)
{
        u32 rate_flags;
        int rate_idx;
        u8 rts_retry_limit;
        u8 data_retry_limit;
        u8 rate_plcp;

        /* Set retry limit on DATA packets and Probe Responses*/
        if (ieee80211_is_probe_resp(fc))
                data_retry_limit = 3;
        else
                data_retry_limit = IWLAGN_DEFAULT_TX_RETRY;
        tx_cmd->data_retry_limit = data_retry_limit;

        /* Set retry limit on RTS packets */
        rts_retry_limit = RTS_DFAULT_RETRY_LIMIT;
        if (data_retry_limit < rts_retry_limit)
                rts_retry_limit = data_retry_limit;
        tx_cmd->rts_retry_limit = rts_retry_limit;

        /* DATA packets will use the uCode station table for rate/antenna
         * selection */
        if (ieee80211_is_data(fc)) {
                tx_cmd->initial_rate_index = 0;
                tx_cmd->tx_flags |= TX_CMD_FLG_STA_RATE_MSK;
                return;
        }

        /**
         * If the current TX rate stored in mac80211 has the MCS bit set, it's
         * not really a TX rate.  Thus, we use the lowest supported rate for
         * this band.  Also use the lowest supported rate if the stored rate
         * index is invalid.
         */
        rate_idx = info->control.rates[0].idx;
        if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS ||
                        (rate_idx < 0) || (rate_idx > IWL_RATE_COUNT_LEGACY))
                rate_idx = rate_lowest_index(&priv->bands[info->band],
                                info->control.sta);
        /* For 5 GHZ band, remap mac80211 rate indices into driver indices */
        if (info->band == IEEE80211_BAND_5GHZ)
                rate_idx += IWL_FIRST_OFDM_RATE;
        /* Get PLCP rate for tx_cmd->rate_n_flags */
        rate_plcp = iwl_rates[rate_idx].plcp;
        /* Zero out flags for this packet */
        rate_flags = 0;

        /* Set CCK flag as needed */
        if ((rate_idx >= IWL_FIRST_CCK_RATE) && (rate_idx <= IWL_LAST_CCK_RATE))
                rate_flags |= RATE_MCS_CCK_MSK;

        /* Set up antennas */
         if (priv->cfg->bt_params &&
             priv->cfg->bt_params->advanced_bt_coexist &&
             priv->bt_full_concurrent) {
                /* operated as 1x1 in full concurrency mode */
                priv->mgmt_tx_ant = iwl_toggle_tx_ant(priv, priv->mgmt_tx_ant,
                                first_antenna(priv->hw_params.valid_tx_ant));
        } else
                priv->mgmt_tx_ant = iwl_toggle_tx_ant(priv, priv->mgmt_tx_ant,
                                              priv->hw_params.valid_tx_ant);
        rate_flags |= iwl_ant_idx_to_flags(priv->mgmt_tx_ant);

        /* Set the rate in the TX cmd */
        tx_cmd->rate_n_flags = iwl_hw_set_rate_n_flags(rate_plcp, rate_flags);
}

static void iwlagn_tx_cmd_build_hwcrypto(struct iwl_priv *priv,
                                      struct ieee80211_tx_info *info,
                                      struct iwl_tx_cmd *tx_cmd,
                                      struct sk_buff *skb_frag,
                                      int sta_id)
{
        struct ieee80211_key_conf *keyconf = info->control.hw_key;

        switch (keyconf->cipher) {
        case WLAN_CIPHER_SUITE_CCMP:
                tx_cmd->sec_ctl = TX_CMD_SEC_CCM;
                memcpy(tx_cmd->key, keyconf->key, keyconf->keylen);
                if (info->flags & IEEE80211_TX_CTL_AMPDU)
                        tx_cmd->tx_flags |= TX_CMD_FLG_AGG_CCMP_MSK;
                IWL_DEBUG_TX(priv, "tx_cmd with AES hwcrypto\n");
                break;

        case WLAN_CIPHER_SUITE_TKIP:
                tx_cmd->sec_ctl = TX_CMD_SEC_TKIP;
                ieee80211_get_tkip_key(keyconf, skb_frag,
                        IEEE80211_TKIP_P2_KEY, tx_cmd->key);
                IWL_DEBUG_TX(priv, "tx_cmd with tkip hwcrypto\n");
                break;

        case WLAN_CIPHER_SUITE_WEP104:
                tx_cmd->sec_ctl |= TX_CMD_SEC_KEY128;
                /* fall through */
        case WLAN_CIPHER_SUITE_WEP40:
                tx_cmd->sec_ctl |= (TX_CMD_SEC_WEP |
                        (keyconf->keyidx & TX_CMD_SEC_MSK) << TX_CMD_SEC_SHIFT);

                memcpy(&tx_cmd->key[3], keyconf->key, keyconf->keylen);

                IWL_DEBUG_TX(priv, "Configuring packet for WEP encryption "
                             "with key %d\n", keyconf->keyidx);
                break;

        default:
                IWL_ERR(priv, "Unknown encode cipher %x\n", keyconf->cipher);
                break;
        }
}

/*
 * start REPLY_TX command process
 */
int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
        struct ieee80211_sta *sta = info->control.sta;
        struct iwl_station_priv *sta_priv = NULL;
        struct iwl_tx_queue *txq;
        struct iwl_queue *q;
        struct iwl_device_cmd *out_cmd;
        struct iwl_cmd_meta *out_meta;
        struct iwl_tx_cmd *tx_cmd;
        struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
        int swq_id, txq_id;
        dma_addr_t phys_addr;
        dma_addr_t txcmd_phys;
        dma_addr_t scratch_phys;
        u16 len, len_org, firstlen, secondlen;
        u16 seq_number = 0;
        __le16 fc;
        u8 hdr_len;
        u8 sta_id;
        u8 wait_write_ptr = 0;
        u8 tid = 0;
        u8 *qc = NULL;
        unsigned long flags;

        if (info->control.vif)
                ctx = iwl_rxon_ctx_from_vif(info->control.vif);

        spin_lock_irqsave(&priv->lock, flags);
        if (iwl_is_rfkill(priv)) {
                IWL_DEBUG_DROP(priv, "Dropping - RF KILL\n");
                goto drop_unlock;
        }

        fc = hdr->frame_control;

#ifdef CONFIG_IWLWIFI_DEBUG
        if (ieee80211_is_auth(fc))
                IWL_DEBUG_TX(priv, "Sending AUTH frame\n");
        else if (ieee80211_is_assoc_req(fc))
                IWL_DEBUG_TX(priv, "Sending ASSOC frame\n");
        else if (ieee80211_is_reassoc_req(fc))
                IWL_DEBUG_TX(priv, "Sending REASSOC frame\n");
#endif

        hdr_len = ieee80211_hdrlen(fc);

        /* Find index into station table for destination station */
        sta_id = iwl_sta_id_or_broadcast(priv, ctx, info->control.sta);
        if (sta_id == IWL_INVALID_STATION) {
                IWL_DEBUG_DROP(priv, "Dropping - INVALID STATION: %pM\n",
                               hdr->addr1);
                goto drop_unlock;
        }

        IWL_DEBUG_TX(priv, "station Id %d\n", sta_id);

        if (sta)
                sta_priv = (void *)sta->drv_priv;

        if (sta_priv && sta_priv->asleep) {
                WARN_ON(!(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE));
                /*
                 * This sends an asynchronous command to the device,
                 * but we can rely on it being processed before the
                 * next frame is processed -- and the next frame to
                 * this station is the one that will consume this
                 * counter.
                 * For now set the counter to just 1 since we do not
                 * support uAPSD yet.
                 */
                iwl_sta_modify_sleep_tx_count(priv, sta_id, 1);
        }

        /*
         * Send this frame after DTIM -- there's a special queue
         * reserved for this for contexts that support AP mode.
         */
        if (info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM) {
                txq_id = ctx->mcast_queue;
                /*
                 * The microcode will clear the more data
                 * bit in the last frame it transmits.
                 */
                hdr->frame_control |=
                        cpu_to_le16(IEEE80211_FCTL_MOREDATA);
        } else
                txq_id = ctx->ac_to_queue[skb_get_queue_mapping(skb)];

        /* irqs already disabled/saved above when locking priv->lock */
        spin_lock(&priv->sta_lock);

        if (ieee80211_is_data_qos(fc)) {
                qc = ieee80211_get_qos_ctl(hdr);
                tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
                if (WARN_ON_ONCE(tid >= MAX_TID_COUNT)) {
                        spin_unlock(&priv->sta_lock);
                        goto drop_unlock;
                }
                seq_number = priv->stations[sta_id].tid[tid].seq_number;
                seq_number &= IEEE80211_SCTL_SEQ;
                hdr->seq_ctrl = hdr->seq_ctrl &
                                cpu_to_le16(IEEE80211_SCTL_FRAG);
                hdr->seq_ctrl |= cpu_to_le16(seq_number);
                seq_number += 0x10;
                /* aggregation is on for this <sta,tid> */
                if (info->flags & IEEE80211_TX_CTL_AMPDU &&
                    priv->stations[sta_id].tid[tid].agg.state == IWL_AGG_ON) {
                        txq_id = priv->stations[sta_id].tid[tid].agg.txq_id;
                }
        }

        txq = &priv->txq[txq_id];
        swq_id = txq->swq_id;
        q = &txq->q;

        if (unlikely(iwl_queue_space(q) < q->high_mark)) {
                spin_unlock(&priv->sta_lock);
                goto drop_unlock;
        }

        if (ieee80211_is_data_qos(fc)) {
                priv->stations[sta_id].tid[tid].tfds_in_queue++;
                if (!ieee80211_has_morefrags(fc))
                        priv->stations[sta_id].tid[tid].seq_number = seq_number;
        }

        spin_unlock(&priv->sta_lock);

        /* Set up driver data for this TFD */
        memset(&(txq->txb[q->write_ptr]), 0, sizeof(struct iwl_tx_info));
        txq->txb[q->write_ptr].skb = skb;
        txq->txb[q->write_ptr].ctx = ctx;

        /* Set up first empty entry in queue's array of Tx/cmd buffers */
        out_cmd = txq->cmd[q->write_ptr];
        out_meta = &txq->meta[q->write_ptr];
        tx_cmd = &out_cmd->cmd.tx;
        memset(&out_cmd->hdr, 0, sizeof(out_cmd->hdr));
        memset(tx_cmd, 0, sizeof(struct iwl_tx_cmd));

        /*
         * Set up the Tx-command (not MAC!) header.
         * Store the chosen Tx queue and TFD index within the sequence field;
         * after Tx, uCode's Tx response will return this value so driver can
         * locate the frame within the tx queue and do post-tx processing.
         */
        out_cmd->hdr.cmd = REPLY_TX;
        out_cmd->hdr.sequence = cpu_to_le16((u16)(QUEUE_TO_SEQ(txq_id) |
                                INDEX_TO_SEQ(q->write_ptr)));

        /* Copy MAC header from skb into command buffer */
        memcpy(tx_cmd->hdr, hdr, hdr_len);


        /* Total # bytes to be transmitted */
        len = (u16)skb->len;
        tx_cmd->len = cpu_to_le16(len);

        if (info->control.hw_key)
                iwlagn_tx_cmd_build_hwcrypto(priv, info, tx_cmd, skb, sta_id);

        /* TODO need this for burst mode later on */
        iwlagn_tx_cmd_build_basic(priv, skb, tx_cmd, info, hdr, sta_id);
        iwl_dbg_log_tx_data_frame(priv, len, hdr);

        iwlagn_tx_cmd_build_rate(priv, tx_cmd, info, fc);

        iwl_update_stats(priv, true, fc, len);
        /*
         * Use the first empty entry in this queue's command buffer array
         * to contain the Tx command and MAC header concatenated together
         * (payload data will be in another buffer).
         * Size of this varies, due to varying MAC header length.
         * If end is not dword aligned, we'll have 2 extra bytes at the end
         * of the MAC header (device reads on dword boundaries).
         * We'll tell device about this padding later.
         */
        len = sizeof(struct iwl_tx_cmd) +
                sizeof(struct iwl_cmd_header) + hdr_len;

        len_org = len;
        firstlen = len = (len + 3) & ~3;

        if (len_org != len)
                len_org = 1;
        else
                len_org = 0;

        /* Tell NIC about any 2-byte padding after MAC header */
        if (len_org)
                tx_cmd->tx_flags |= TX_CMD_FLG_MH_PAD_MSK;

        /* Physical address of this Tx command's header (not MAC header!),
         * within command buffer array. */
        txcmd_phys = pci_map_single(priv->pci_dev,
                                    &out_cmd->hdr, len,
                                    PCI_DMA_BIDIRECTIONAL);
        dma_unmap_addr_set(out_meta, mapping, txcmd_phys);
        dma_unmap_len_set(out_meta, len, len);
        /* Add buffer containing Tx command and MAC(!) header to TFD's
         * first entry */
        priv->cfg->ops->lib->txq_attach_buf_to_tfd(priv, txq,
                                                   txcmd_phys, len, 1, 0);

        if (!ieee80211_has_morefrags(hdr->frame_control)) {
                txq->need_update = 1;
        } else {
                wait_write_ptr = 1;
                txq->need_update = 0;
        }

        /* Set up TFD's 2nd entry to point directly to remainder of skb,
         * if any (802.11 null frames have no payload). */
        secondlen = len = skb->len - hdr_len;
        if (len) {
                phys_addr = pci_map_single(priv->pci_dev, skb->data + hdr_len,
                                           len, PCI_DMA_TODEVICE);
                priv->cfg->ops->lib->txq_attach_buf_to_tfd(priv, txq,
                                                           phys_addr, len,
                                                           0, 0);
        }

        scratch_phys = txcmd_phys + sizeof(struct iwl_cmd_header) +
                                offsetof(struct iwl_tx_cmd, scratch);

        len = sizeof(struct iwl_tx_cmd) +
                sizeof(struct iwl_cmd_header) + hdr_len;
        /* take back ownership of DMA buffer to enable update */
        pci_dma_sync_single_for_cpu(priv->pci_dev, txcmd_phys,
                                    len, PCI_DMA_BIDIRECTIONAL);
        tx_cmd->dram_lsb_ptr = cpu_to_le32(scratch_phys);
        tx_cmd->dram_msb_ptr = iwl_get_dma_hi_addr(scratch_phys);

        IWL_DEBUG_TX(priv, "sequence nr = 0X%x\n",
                     le16_to_cpu(out_cmd->hdr.sequence));
        IWL_DEBUG_TX(priv, "tx_flags = 0X%x\n", le32_to_cpu(tx_cmd->tx_flags));
        iwl_print_hex_dump(priv, IWL_DL_TX, (u8 *)tx_cmd, sizeof(*tx_cmd));
        iwl_print_hex_dump(priv, IWL_DL_TX, (u8 *)tx_cmd->hdr, hdr_len);

        /* Set up entry for this TFD in Tx byte-count array */
        if (info->flags & IEEE80211_TX_CTL_AMPDU)
                priv->cfg->ops->lib->txq_update_byte_cnt_tbl(priv, txq,
                                                     le16_to_cpu(tx_cmd->len));

        pci_dma_sync_single_for_device(priv->pci_dev, txcmd_phys,
                                       len, PCI_DMA_BIDIRECTIONAL);

        trace_iwlwifi_dev_tx(priv,
                             &((struct iwl_tfd *)txq->tfds)[txq->q.write_ptr],
                             sizeof(struct iwl_tfd),
                             &out_cmd->hdr, firstlen,
                             skb->data + hdr_len, secondlen);

        /* Tell device the write index *just past* this latest filled TFD */
        q->write_ptr = iwl_queue_inc_wrap(q->write_ptr, q->n_bd);
        iwl_txq_update_write_ptr(priv, txq);
        spin_unlock_irqrestore(&priv->lock, flags);

        /*
         * At this point the frame is "transmitted" successfully
         * and we will get a TX status notification eventually,
         * regardless of the value of ret. "ret" only indicates
         * whether or not we should update the write pointer.
         */

        /* avoid atomic ops if it isn't an associated client */
        if (sta_priv && sta_priv->client)
                atomic_inc(&sta_priv->pending_frames);

        if ((iwl_queue_space(q) < q->high_mark) && priv->mac80211_registered) {
                if (wait_write_ptr) {
                        spin_lock_irqsave(&priv->lock, flags);
                        txq->need_update = 1;
                        iwl_txq_update_write_ptr(priv, txq);
                        spin_unlock_irqrestore(&priv->lock, flags);
                } else {
                        iwl_stop_queue(priv, txq->swq_id);
                }
        }

        return 0;

drop_unlock:
        spin_unlock_irqrestore(&priv->lock, flags);
        return -1;
}

static inline int iwlagn_alloc_dma_ptr(struct iwl_priv *priv,
                                    struct iwl_dma_ptr *ptr, size_t size)
{
        ptr->addr = dma_alloc_coherent(&priv->pci_dev->dev, size, &ptr->dma,
                                       GFP_KERNEL);
        if (!ptr->addr)
                return -ENOMEM;
        ptr->size = size;
        return 0;
}

static inline void iwlagn_free_dma_ptr(struct iwl_priv *priv,
                                    struct iwl_dma_ptr *ptr)
{
        if (unlikely(!ptr->addr))
                return;

        dma_free_coherent(&priv->pci_dev->dev, ptr->size, ptr->addr, ptr->dma);
        memset(ptr, 0, sizeof(*ptr));
}

/**
 * iwlagn_hw_txq_ctx_free - Free TXQ Context
 *
 * Destroy all TX DMA queues and structures
 */
void iwlagn_hw_txq_ctx_free(struct iwl_priv *priv)
{
        int txq_id;

        /* Tx queues */
        if (priv->txq) {
                for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++)
                        if (txq_id == priv->cmd_queue)
                                iwl_cmd_queue_free(priv);
                        else
                                iwl_tx_queue_free(priv, txq_id);
        }
        iwlagn_free_dma_ptr(priv, &priv->kw);

        iwlagn_free_dma_ptr(priv, &priv->scd_bc_tbls);

        /* free tx queue structure */
        iwl_free_txq_mem(priv);
}

/**
 * iwlagn_txq_ctx_alloc - allocate TX queue context
 * Allocate all Tx DMA structures and initialize them
 *
 * @param priv
 * @return error code
 */
int iwlagn_txq_ctx_alloc(struct iwl_priv *priv)
{
        int ret;
        int txq_id, slots_num;
        unsigned long flags;

        /* Free all tx/cmd queues and keep-warm buffer */
        iwlagn_hw_txq_ctx_free(priv);

        ret = iwlagn_alloc_dma_ptr(priv, &priv->scd_bc_tbls,
                                priv->hw_params.scd_bc_tbls_size);
        if (ret) {
                IWL_ERR(priv, "Scheduler BC Table allocation failed\n");
                goto error_bc_tbls;
        }
        /* Alloc keep-warm buffer */
        ret = iwlagn_alloc_dma_ptr(priv, &priv->kw, IWL_KW_SIZE);
        if (ret) {
                IWL_ERR(priv, "Keep Warm allocation failed\n");
                goto error_kw;
        }

        /* allocate tx queue structure */
        ret = iwl_alloc_txq_mem(priv);
        if (ret)
                goto error;

        spin_lock_irqsave(&priv->lock, flags);

        /* Turn off all Tx DMA fifos */
        priv->cfg->ops->lib->txq_set_sched(priv, 0);

        /* Tell NIC where to find the "keep warm" buffer */
        iwl_write_direct32(priv, FH_KW_MEM_ADDR_REG, priv->kw.dma >> 4);

        spin_unlock_irqrestore(&priv->lock, flags);

        /* Alloc and init all Tx queues, including the command queue (#4/#9) */
        for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++) {
                slots_num = (txq_id == priv->cmd_queue) ?
                                        TFD_CMD_SLOTS : TFD_TX_CMD_SLOTS;
                ret = iwl_tx_queue_init(priv, &priv->txq[txq_id], slots_num,
                                       txq_id);
                if (ret) {
                        IWL_ERR(priv, "Tx %d queue init failed\n", txq_id);
                        goto error;
                }
        }

        return ret;

 error:
        iwlagn_hw_txq_ctx_free(priv);
        iwlagn_free_dma_ptr(priv, &priv->kw);
 error_kw:
        iwlagn_free_dma_ptr(priv, &priv->scd_bc_tbls);
 error_bc_tbls:
        return ret;
}

void iwlagn_txq_ctx_reset(struct iwl_priv *priv)
{
        int txq_id, slots_num;
        unsigned long flags;

        spin_lock_irqsave(&priv->lock, flags);

        /* Turn off all Tx DMA fifos */
        priv->cfg->ops->lib->txq_set_sched(priv, 0);

        /* Tell NIC where to find the "keep warm" buffer */
        iwl_write_direct32(priv, FH_KW_MEM_ADDR_REG, priv->kw.dma >> 4);

        spin_unlock_irqrestore(&priv->lock, flags);

        /* Alloc and init all Tx queues, including the command queue (#4) */
        for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++) {
                slots_num = txq_id == priv->cmd_queue ?
                            TFD_CMD_SLOTS : TFD_TX_CMD_SLOTS;
                iwl_tx_queue_reset(priv, &priv->txq[txq_id], slots_num, txq_id);
        }
}

/**
 * iwlagn_txq_ctx_stop - Stop all Tx DMA channels
 */
void iwlagn_txq_ctx_stop(struct iwl_priv *priv)
{
        int ch;
        unsigned long flags;

        /* Turn off all Tx DMA fifos */
        spin_lock_irqsave(&priv->lock, flags);

        priv->cfg->ops->lib->txq_set_sched(priv, 0);

        /* Stop each Tx DMA channel, and wait for it to be idle */
        for (ch = 0; ch < priv->hw_params.dma_chnl_num; ch++) {
                iwl_write_direct32(priv, FH_TCSR_CHNL_TX_CONFIG_REG(ch), 0x0);
                if (iwl_poll_direct_bit(priv, FH_TSSR_TX_STATUS_REG,
                                    FH_TSSR_TX_STATUS_REG_MSK_CHNL_IDLE(ch),
                                    1000))
                        IWL_ERR(priv, "Failing on timeout while stopping"
                            " DMA channel %d [0x%08x]", ch,
                            iwl_read_direct32(priv, FH_TSSR_TX_STATUS_REG));
        }
        spin_unlock_irqrestore(&priv->lock, flags);
}

/*
 * Find first available (lowest unused) Tx Queue, mark it "active".
 * Called only when finding queue for aggregation.
 * Should never return anything < 7, because they should already
 * be in use as EDCA AC (0-3), Command (4), reserved (5, 6)
 */
static int iwlagn_txq_ctx_activate_free(struct iwl_priv *priv)
{
        int txq_id;

        for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++)
                if (!test_and_set_bit(txq_id, &priv->txq_ctx_active_msk))
                        return txq_id;
        return -1;
}

int iwlagn_tx_agg_start(struct iwl_priv *priv, struct ieee80211_vif *vif,
                        struct ieee80211_sta *sta, u16 tid, u16 *ssn)
{
        int sta_id;
        int tx_fifo;
        int txq_id;
        int ret;
        unsigned long flags;
        struct iwl_tid_data *tid_data;

        tx_fifo = get_fifo_from_tid(iwl_rxon_ctx_from_vif(vif), tid);
        if (unlikely(tx_fifo < 0))
                return tx_fifo;

        IWL_WARN(priv, "%s on ra = %pM tid = %d\n",
                        __func__, sta->addr, tid);

        sta_id = iwl_sta_id(sta);
        if (sta_id == IWL_INVALID_STATION) {
                IWL_ERR(priv, "Start AGG on invalid station\n");
                return -ENXIO;
        }
        if (unlikely(tid >= MAX_TID_COUNT))
                return -EINVAL;

        if (priv->stations[sta_id].tid[tid].agg.state != IWL_AGG_OFF) {
                IWL_ERR(priv, "Start AGG when state is not IWL_AGG_OFF !\n");
                return -ENXIO;
        }

        txq_id = iwlagn_txq_ctx_activate_free(priv);
        if (txq_id == -1) {
                IWL_ERR(priv, "No free aggregation queue available\n");
                return -ENXIO;
        }

        spin_lock_irqsave(&priv->sta_lock, flags);
        tid_data = &priv->stations[sta_id].tid[tid];
        *ssn = SEQ_TO_SN(tid_data->seq_number);
        tid_data->agg.txq_id = txq_id;
        priv->txq[txq_id].swq_id = iwl_virtual_agg_queue_num(get_ac_from_tid(tid), txq_id);
        spin_unlock_irqrestore(&priv->sta_lock, flags);

        ret = priv->cfg->ops->lib->txq_agg_enable(priv, txq_id, tx_fifo,
                                                  sta_id, tid, *ssn);
        if (ret)
                return ret;

        spin_lock_irqsave(&priv->sta_lock, flags);
        tid_data = &priv->stations[sta_id].tid[tid];
        if (tid_data->tfds_in_queue == 0) {
                IWL_DEBUG_HT(priv, "HW queue is empty\n");
                tid_data->agg.state = IWL_AGG_ON;
                ieee80211_start_tx_ba_cb_irqsafe(vif, sta->addr, tid);
        } else {
                IWL_DEBUG_HT(priv, "HW queue is NOT empty: %d packets in HW queue\n",
                             tid_data->tfds_in_queue);
                tid_data->agg.state = IWL_EMPTYING_HW_QUEUE_ADDBA;
        }
        spin_unlock_irqrestore(&priv->sta_lock, flags);
        return ret;
}

int iwlagn_tx_agg_stop(struct iwl_priv *priv, struct ieee80211_vif *vif,
                       struct ieee80211_sta *sta, u16 tid)
{
        int tx_fifo_id, txq_id, sta_id, ssn;
        struct iwl_tid_data *tid_data;
        int write_ptr, read_ptr;
        unsigned long flags;

        tx_fifo_id = get_fifo_from_tid(iwl_rxon_ctx_from_vif(vif), tid);
        if (unlikely(tx_fifo_id < 0))
                return tx_fifo_id;

        sta_id = iwl_sta_id(sta);

        if (sta_id == IWL_INVALID_STATION) {
                IWL_ERR(priv, "Invalid station for AGG tid %d\n", tid);
                return -ENXIO;
        }

        spin_lock_irqsave(&priv->sta_lock, flags);

        tid_data = &priv->stations[sta_id].tid[tid];
        ssn = (tid_data->seq_number & IEEE80211_SCTL_SEQ) >> 4;
        txq_id = tid_data->agg.txq_id;

        switch (priv->stations[sta_id].tid[tid].agg.state) {
        case IWL_EMPTYING_HW_QUEUE_ADDBA:
                /*
                 * This can happen if the peer stops aggregation
                 * again before we've had a chance to drain the
                 * queue we selected previously, i.e. before the
                 * session was really started completely.
                 */
                IWL_DEBUG_HT(priv, "AGG stop before setup done\n");
                goto turn_off;
        case IWL_AGG_ON:
                break;
        default:
                IWL_WARN(priv, "Stopping AGG while state not ON or starting\n");
        }

        write_ptr = priv->txq[txq_id].q.write_ptr;
        read_ptr = priv->txq[txq_id].q.read_ptr;

        /* The queue is not empty */
        if (write_ptr != read_ptr) {
                IWL_DEBUG_HT(priv, "Stopping a non empty AGG HW QUEUE\n");
                priv->stations[sta_id].tid[tid].agg.state =
                                IWL_EMPTYING_HW_QUEUE_DELBA;
                spin_unlock_irqrestore(&priv->sta_lock, flags);
                return 0;
        }

        IWL_DEBUG_HT(priv, "HW queue is empty\n");
 turn_off:
        priv->stations[sta_id].tid[tid].agg.state = IWL_AGG_OFF;

        /* do not restore/save irqs */
        spin_unlock(&priv->sta_lock);
        spin_lock(&priv->lock);

        /*
         * the only reason this call can fail is queue number out of range,
         * which can happen if uCode is reloaded and all the station
         * information are lost. if it is outside the range, there is no need
         * to deactivate the uCode queue, just return "success" to allow
         *  mac80211 to clean up it own data.
         */
        priv->cfg->ops->lib->txq_agg_disable(priv, txq_id, ssn,
                                                   tx_fifo_id);
        spin_unlock_irqrestore(&priv->lock, flags);

        ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);

        return 0;
}

int iwlagn_txq_check_empty(struct iwl_priv *priv,
                           int sta_id, u8 tid, int txq_id)
{
        struct iwl_queue *q = &priv->txq[txq_id].q;
        u8 *addr = priv->stations[sta_id].sta.sta.addr;
        struct iwl_tid_data *tid_data = &priv->stations[sta_id].tid[tid];
        struct iwl_rxon_context *ctx;

        ctx = &priv->contexts[priv->stations[sta_id].ctxid];

        lockdep_assert_held(&priv->sta_lock);

        switch (priv->stations[sta_id].tid[tid].agg.state) {
        case IWL_EMPTYING_HW_QUEUE_DELBA:
                /* We are reclaiming the last packet of the */
                /* aggregated HW queue */
                if ((txq_id  == tid_data->agg.txq_id) &&
                    (q->read_ptr == q->write_ptr)) {
                        u16 ssn = SEQ_TO_SN(tid_data->seq_number);
                        int tx_fifo = get_fifo_from_tid(ctx, tid);
                        IWL_DEBUG_HT(priv, "HW queue empty: continue DELBA flow\n");
                        priv->cfg->ops->lib->txq_agg_disable(priv, txq_id,
                                                             ssn, tx_fifo);
                        tid_data->agg.state = IWL_AGG_OFF;
                        ieee80211_stop_tx_ba_cb_irqsafe(ctx->vif, addr, tid);
                }
                break;
        case IWL_EMPTYING_HW_QUEUE_ADDBA:
                /* We are reclaiming the last packet of the queue */
                if (tid_data->tfds_in_queue == 0) {
                        IWL_DEBUG_HT(priv, "HW queue empty: continue ADDBA flow\n");
                        tid_data->agg.state = IWL_AGG_ON;
                        ieee80211_start_tx_ba_cb_irqsafe(ctx->vif, addr, tid);
                }
                break;
        }

        return 0;
}

static void iwlagn_tx_status(struct iwl_priv *priv, struct iwl_tx_info *tx_info)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx_info->skb->data;
        struct ieee80211_sta *sta;
        struct iwl_station_priv *sta_priv;

        rcu_read_lock();
        sta = ieee80211_find_sta(tx_info->ctx->vif, hdr->addr1);
        if (sta) {
                sta_priv = (void *)sta->drv_priv;
                /* avoid atomic ops if this isn't a client */
                if (sta_priv->client &&
                    atomic_dec_return(&sta_priv->pending_frames) == 0)
                        ieee80211_sta_block_awake(priv->hw, sta, false);
        }
        rcu_read_unlock();

        ieee80211_tx_status_irqsafe(priv->hw, tx_info->skb);
}

int iwlagn_tx_queue_reclaim(struct iwl_priv *priv, int txq_id, int index)
{
        struct iwl_tx_queue *txq = &priv->txq[txq_id];
        struct iwl_queue *q = &txq->q;
        struct iwl_tx_info *tx_info;
        int nfreed = 0;
        struct ieee80211_hdr *hdr;

        if ((index >= q->n_bd) || (iwl_queue_used(q, index) == 0)) {
                IWL_ERR(priv, "Read index for DMA queue txq id (%d), index %d, "
                          "is out of range [0-%d] %d %d.\n", txq_id,
                          index, q->n_bd, q->write_ptr, q->read_ptr);
                return 0;
        }

        for (index = iwl_queue_inc_wrap(index, q->n_bd);
             q->read_ptr != index;
             q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) {

                tx_info = &txq->txb[txq->q.read_ptr];
                iwlagn_tx_status(priv, tx_info);

                hdr = (struct ieee80211_hdr *)tx_info->skb->data;
                if (hdr && ieee80211_is_data_qos(hdr->frame_control))
                        nfreed++;
                tx_info->skb = NULL;

                if (priv->cfg->ops->lib->txq_inval_byte_cnt_tbl)
                        priv->cfg->ops->lib->txq_inval_byte_cnt_tbl(priv, txq);

                priv->cfg->ops->lib->txq_free_tfd(priv, txq);
        }
        return nfreed;
}

/**
 * iwlagn_tx_status_reply_compressed_ba - Update tx status from block-ack
 *
 * Go through block-ack's bitmap of ACK'd frames, update driver's record of
 * ACK vs. not.  This gets sent to mac80211, then to rate scaling algo.
 */
static int iwlagn_tx_status_reply_compressed_ba(struct iwl_priv *priv,
                                 struct iwl_ht_agg *agg,
                                 struct iwl_compressed_ba_resp *ba_resp)

{
        int i, sh, ack;
        u16 seq_ctl = le16_to_cpu(ba_resp->seq_ctl);
        u16 scd_flow = le16_to_cpu(ba_resp->scd_flow);
        u64 bitmap, sent_bitmap;
        int successes = 0;
        struct ieee80211_tx_info *info;

        if (unlikely(!agg->wait_for_ba))  {
                IWL_ERR(priv, "Received BA when not expected\n");
                return -EINVAL;
        }

        /* Mark that the expected block-ack response arrived */
        agg->wait_for_ba = 0;
        IWL_DEBUG_TX_REPLY(priv, "BA %d %d\n", agg->start_idx, ba_resp->seq_ctl);

        /* Calculate shift to align block-ack bits with our Tx window bits */
        sh = agg->start_idx - SEQ_TO_INDEX(seq_ctl >> 4);
        if (sh < 0) /* tbw something is wrong with indices */
                sh += 0x100;

        /* don't use 64-bit values for now */
        bitmap = le64_to_cpu(ba_resp->bitmap) >> sh;

        if (agg->frame_count > (64 - sh)) {
                IWL_DEBUG_TX_REPLY(priv, "more frames than bitmap size");
                return -1;
        }

        /* check for success or failure according to the
         * transmitted bitmap and block-ack bitmap */
        sent_bitmap = bitmap & agg->bitmap;

        /* For each frame attempted in aggregation,
         * update driver's record of tx frame's status. */
        i = 0;
        while (sent_bitmap) {
                ack = sent_bitmap & 1ULL;
                successes += ack;
                IWL_DEBUG_TX_REPLY(priv, "%s ON i=%d idx=%d raw=%d\n",
                        ack ? "ACK" : "NACK", i, (agg->start_idx + i) & 0xff,
                        agg->start_idx + i);
                sent_bitmap >>= 1;
                ++i;
        }

        info = IEEE80211_SKB_CB(priv->txq[scd_flow].txb[agg->start_idx].skb);
        memset(&info->status, 0, sizeof(info->status));
        info->flags |= IEEE80211_TX_STAT_ACK;
        info->flags |= IEEE80211_TX_STAT_AMPDU;
        info->status.ampdu_ack_len = successes;
        info->status.ampdu_len = agg->frame_count;
        iwlagn_hwrate_to_tx_control(priv, agg->rate_n_flags, info);

        IWL_DEBUG_TX_REPLY(priv, "Bitmap %llx\n", (unsigned long long)bitmap);

        return 0;
}

/**
 * translate ucode response to mac80211 tx status control values
 */
void iwlagn_hwrate_to_tx_control(struct iwl_priv *priv, u32 rate_n_flags,
                                  struct ieee80211_tx_info *info)
{
        struct ieee80211_tx_rate *r = &info->control.rates[0];

        info->antenna_sel_tx =
                ((rate_n_flags & RATE_MCS_ANT_ABC_MSK) >> RATE_MCS_ANT_POS);
        if (rate_n_flags & RATE_MCS_HT_MSK)
                r->flags |= IEEE80211_TX_RC_MCS;
        if (rate_n_flags & RATE_MCS_GF_MSK)
                r->flags |= IEEE80211_TX_RC_GREEN_FIELD;
        if (rate_n_flags & RATE_MCS_HT40_MSK)
                r->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
        if (rate_n_flags & RATE_MCS_DUP_MSK)
                r->flags |= IEEE80211_TX_RC_DUP_DATA;
        if (rate_n_flags & RATE_MCS_SGI_MSK)
                r->flags |= IEEE80211_TX_RC_SHORT_GI;
        r->idx = iwlagn_hwrate_to_mac80211_idx(rate_n_flags, info->band);
}

/**
 * iwlagn_rx_reply_compressed_ba - Handler for REPLY_COMPRESSED_BA
 *
 * Handles block-acknowledge notification from device, which reports success
 * of frames sent via aggregation.
 */
void iwlagn_rx_reply_compressed_ba(struct iwl_priv *priv,
                                           struct iwl_rx_mem_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_compressed_ba_resp *ba_resp = &pkt->u.compressed_ba;
        struct iwl_tx_queue *txq = NULL;
        struct iwl_ht_agg *agg;
        int index;
        int sta_id;
        int tid;
        unsigned long flags;

        /* "flow" corresponds to Tx queue */
        u16 scd_flow = le16_to_cpu(ba_resp->scd_flow);

        /* "ssn" is start of block-ack Tx window, corresponds to index
         * (in Tx queue's circular buffer) of first TFD/frame in window */
        u16 ba_resp_scd_ssn = le16_to_cpu(ba_resp->scd_ssn);

        if (scd_flow >= priv->hw_params.max_txq_num) {
                IWL_ERR(priv,
                        "BUG_ON scd_flow is bigger than number of queues\n");
                return;
        }

        txq = &priv->txq[scd_flow];
        sta_id = ba_resp->sta_id;
        tid = ba_resp->tid;
        agg = &priv->stations[sta_id].tid[tid].agg;
        if (unlikely(agg->txq_id != scd_flow)) {
                /*
                 * FIXME: this is a uCode bug which need to be addressed,
                 * log the information and return for now!
                 * since it is possible happen very often and in order
                 * not to fill the syslog, don't enable the logging by default
                 */
                IWL_DEBUG_TX_REPLY(priv,
                        "BA scd_flow %d does not match txq_id %d\n",
                        scd_flow, agg->txq_id);
                return;
        }

        /* Find index just before block-ack window */
        index = iwl_queue_dec_wrap(ba_resp_scd_ssn & 0xff, txq->q.n_bd);

        spin_lock_irqsave(&priv->sta_lock, flags);

        IWL_DEBUG_TX_REPLY(priv, "REPLY_COMPRESSED_BA [%d] Received from %pM, "
                           "sta_id = %d\n",
                           agg->wait_for_ba,
                           (u8 *) &ba_resp->sta_addr_lo32,
                           ba_resp->sta_id);
        IWL_DEBUG_TX_REPLY(priv, "TID = %d, SeqCtl = %d, bitmap = 0x%llx, scd_flow = "
                           "%d, scd_ssn = %d\n",
                           ba_resp->tid,
                           ba_resp->seq_ctl,
                           (unsigned long long)le64_to_cpu(ba_resp->bitmap),
                           ba_resp->scd_flow,
                           ba_resp->scd_ssn);
        IWL_DEBUG_TX_REPLY(priv, "DAT start_idx = %d, bitmap = 0x%llx\n",
                           agg->start_idx,
                           (unsigned long long)agg->bitmap);

        /* Update driver's record of ACK vs. not for each frame in window */
        iwlagn_tx_status_reply_compressed_ba(priv, agg, ba_resp);

        /* Release all TFDs before the SSN, i.e. all TFDs in front of
         * block-ack window (we assume that they've been successfully
         * transmitted ... if not, it's too late anyway). */
        if (txq->q.read_ptr != (ba_resp_scd_ssn & 0xff)) {
                /* calculate mac80211 ampdu sw queue to wake */
                int freed = iwlagn_tx_queue_reclaim(priv, scd_flow, index);
                iwl_free_tfds_in_queue(priv, sta_id, tid, freed);

                if ((iwl_queue_space(&txq->q) > txq->q.low_mark) &&
                    priv->mac80211_registered &&
                    (agg->state != IWL_EMPTYING_HW_QUEUE_DELBA))
                        iwl_wake_queue(priv, txq->swq_id);

                iwlagn_txq_check_empty(priv, sta_id, tid, scd_flow);
        }

        spin_unlock_irqrestore(&priv->sta_lock, flags);
}