/*
 * Copyright (c) 2010 Broadcom Corporation
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include <net/mac80211.h>

#include "rate.h"
#include "scb.h"
#include "phy/phy_hal.h"
#include "antsel.h"
#include "main.h"
#include "ampdu.h"
#include "debug.h"
#include "brcms_trace_events.h"

/* max number of mpdus in an ampdu */
#define AMPDU_MAX_MPDU                  32
/* max number of mpdus in an ampdu to a legacy */
#define AMPDU_NUM_MPDU_LEGACY           16
/* max Tx ba window size (in pdu) */
#define AMPDU_TX_BA_MAX_WSIZE           64
/* default Tx ba window size (in pdu) */
#define AMPDU_TX_BA_DEF_WSIZE           64
/* default Rx ba window size (in pdu) */
#define AMPDU_RX_BA_DEF_WSIZE           64
/* max Rx ba window size (in pdu) */
#define AMPDU_RX_BA_MAX_WSIZE           64
/* max dur of tx ampdu (in msec) */
#define AMPDU_MAX_DUR                   5
/* default tx retry limit */
#define AMPDU_DEF_RETRY_LIMIT           5
/* default tx retry limit at reg rate */
#define AMPDU_DEF_RR_RETRY_LIMIT        2
/* default ffpld reserved bytes */
#define AMPDU_DEF_FFPLD_RSVD            2048
/* # of inis to be freed on detach */
#define AMPDU_INI_FREE                  10
/* max # of mpdus released at a time */
#define AMPDU_SCB_MAX_RELEASE           20

#define NUM_FFPLD_FIFO 4        /* number of fifo concerned by pre-loading */
#define FFPLD_TX_MAX_UNFL   200 /* default value of the average number of ampdu
                                 * without underflows
                                 */
#define FFPLD_MPDU_SIZE 1800    /* estimate of maximum mpdu size */
#define FFPLD_MAX_MCS 23        /* we don't deal with mcs 32 */
#define FFPLD_PLD_INCR 1000     /* increments in bytes */
#define FFPLD_MAX_AMPDU_CNT 5000        /* maximum number of ampdu we
                                         * accumulate between resets.
                                         */

#define AMPDU_DELIMITER_LEN     4

/* max allowed number of mpdus in an ampdu (2 streams) */
#define AMPDU_NUM_MPDU          16

#define TX_SEQ_TO_INDEX(seq) ((seq) % AMPDU_TX_BA_MAX_WSIZE)

/* max possible overhead per mpdu in the ampdu; 3 is for roundup if needed */
#define AMPDU_MAX_MPDU_OVERHEAD (FCS_LEN + DOT11_ICV_AES_LEN +\
        AMPDU_DELIMITER_LEN + 3\
        + DOT11_A4_HDR_LEN + DOT11_QOS_LEN + DOT11_IV_MAX_LEN)

/* modulo add/sub, bound = 2^k */
#define MODADD_POW2(x, y, bound) (((x) + (y)) & ((bound) - 1))
#define MODSUB_POW2(x, y, bound) (((x) - (y)) & ((bound) - 1))

/* structure to hold tx fifo information and pre-loading state
 * counters specific to tx underflows of ampdus
 * some counters might be redundant with the ones in wlc or ampdu structures.
 * This allows to maintain a specific state independently of
 * how often and/or when the wlc counters are updated.
 *
 * ampdu_pld_size: number of bytes to be pre-loaded
 * mcs2ampdu_table: per-mcs max # of mpdus in an ampdu
 * prev_txfunfl: num of underflows last read from the HW macstats counter
 * accum_txfunfl: num of underflows since we modified pld params
 * accum_txampdu: num of tx ampdu since we modified pld params
 * prev_txampdu: previous reading of tx ampdu
 * dmaxferrate: estimated dma avg xfer rate in kbits/sec
 */
struct brcms_fifo_info {
        u16 ampdu_pld_size;
        u8 mcs2ampdu_table[FFPLD_MAX_MCS + 1];
        u16 prev_txfunfl;
        u32 accum_txfunfl;
        u32 accum_txampdu;
        u32 prev_txampdu;
        u32 dmaxferrate;
};

/* AMPDU module specific state
 *
 * wlc: pointer to main wlc structure
 * scb_handle: scb cubby handle to retrieve data from scb
 * ini_enable: per-tid initiator enable/disable of ampdu
 * ba_tx_wsize: Tx ba window size (in pdu)
 * ba_rx_wsize: Rx ba window size (in pdu)
 * retry_limit: mpdu transmit retry limit
 * rr_retry_limit: mpdu transmit retry limit at regular rate
 * retry_limit_tid: per-tid mpdu transmit retry limit
 * rr_retry_limit_tid: per-tid mpdu transmit retry limit at regular rate
 * mpdu_density: min mpdu spacing (0-7) ==> 2^(x-1)/8 usec
 * max_pdu: max pdus allowed in ampdu
 * dur: max duration of an ampdu (in msec)
 * rx_factor: maximum rx ampdu factor (0-3) ==> 2^(13+x) bytes
 * ffpld_rsvd: number of bytes to reserve for preload
 * max_txlen: max size of ampdu per mcs, bw and sgi
 * mfbr: enable multiple fallback rate
 * tx_max_funl: underflows should be kept such that
 *              (tx_max_funfl*underflows) < tx frames
 * fifo_tb: table of fifo infos
 */
struct ampdu_info {
        struct brcms_c_info *wlc;
        int scb_handle;
        u8 ini_enable[AMPDU_MAX_SCB_TID];
        u8 ba_tx_wsize;
        u8 ba_rx_wsize;
        u8 retry_limit;
        u8 rr_retry_limit;
        u8 retry_limit_tid[AMPDU_MAX_SCB_TID];
        u8 rr_retry_limit_tid[AMPDU_MAX_SCB_TID];
        u8 mpdu_density;
        s8 max_pdu;
        u8 dur;
        u8 rx_factor;
        u32 ffpld_rsvd;
        u32 max_txlen[MCS_TABLE_SIZE][2][2];
        bool mfbr;
        u32 tx_max_funl;
        struct brcms_fifo_info fifo_tb[NUM_FFPLD_FIFO];
};

static void brcms_c_scb_ampdu_update_max_txlen(struct ampdu_info *ampdu, u8 dur)
{
        u32 rate, mcs;

        for (mcs = 0; mcs < MCS_TABLE_SIZE; mcs++) {
                /* rate is in Kbps; dur is in msec ==> len = (rate * dur) / 8 */
                /* 20MHz, No SGI */
                rate = mcs_2_rate(mcs, false, false);
                ampdu->max_txlen[mcs][0][0] = (rate * dur) >> 3;
                /* 40 MHz, No SGI */
                rate = mcs_2_rate(mcs, true, false);
                ampdu->max_txlen[mcs][1][0] = (rate * dur) >> 3;
                /* 20MHz, SGI */
                rate = mcs_2_rate(mcs, false, true);
                ampdu->max_txlen[mcs][0][1] = (rate * dur) >> 3;
                /* 40 MHz, SGI */
                rate = mcs_2_rate(mcs, true, true);
                ampdu->max_txlen[mcs][1][1] = (rate * dur) >> 3;
        }
}

static bool brcms_c_ampdu_cap(struct ampdu_info *ampdu)
{
        if (BRCMS_PHY_11N_CAP(ampdu->wlc->band))
                return true;
        else
                return false;
}

static int brcms_c_ampdu_set(struct ampdu_info *ampdu, bool on)
{
        struct brcms_c_info *wlc = ampdu->wlc;
        struct bcma_device *core = wlc->hw->d11core;

        wlc->pub->_ampdu = false;

        if (on) {
                if (!(wlc->pub->_n_enab & SUPPORT_11N)) {
                        brcms_err(core, "wl%d: driver not nmode enabled\n",
                                  wlc->pub->unit);
                        return -ENOTSUPP;
                }
                if (!brcms_c_ampdu_cap(ampdu)) {
                        brcms_err(core, "wl%d: device not ampdu capable\n",
                                  wlc->pub->unit);
                        return -ENOTSUPP;
                }
                wlc->pub->_ampdu = on;
        }

        return 0;
}

static void brcms_c_ffpld_init(struct ampdu_info *ampdu)
{
        int i, j;
        struct brcms_fifo_info *fifo;

        for (j = 0; j < NUM_FFPLD_FIFO; j++) {
                fifo = (ampdu->fifo_tb + j);
                fifo->ampdu_pld_size = 0;
                for (i = 0; i <= FFPLD_MAX_MCS; i++)
                        fifo->mcs2ampdu_table[i] = 255;
                fifo->dmaxferrate = 0;
                fifo->accum_txampdu = 0;
                fifo->prev_txfunfl = 0;
                fifo->accum_txfunfl = 0;

        }
}

struct ampdu_info *brcms_c_ampdu_attach(struct brcms_c_info *wlc)
{
        struct ampdu_info *ampdu;
        int i;

        ampdu = kzalloc_obj(*ampdu, GFP_ATOMIC);
        if (!ampdu)
                return NULL;

        ampdu->wlc = wlc;

        for (i = 0; i < AMPDU_MAX_SCB_TID; i++)
                ampdu->ini_enable[i] = true;
        /* Disable ampdu for VO by default */
        ampdu->ini_enable[PRIO_8021D_VO] = false;
        ampdu->ini_enable[PRIO_8021D_NC] = false;

        /* Disable ampdu for BK by default since not enough fifo space */
        ampdu->ini_enable[PRIO_8021D_NONE] = false;
        ampdu->ini_enable[PRIO_8021D_BK] = false;

        ampdu->ba_tx_wsize = AMPDU_TX_BA_DEF_WSIZE;
        ampdu->ba_rx_wsize = AMPDU_RX_BA_DEF_WSIZE;
        ampdu->mpdu_density = AMPDU_DEF_MPDU_DENSITY;
        ampdu->max_pdu = AUTO;
        ampdu->dur = AMPDU_MAX_DUR;

        ampdu->ffpld_rsvd = AMPDU_DEF_FFPLD_RSVD;
        /*
         * bump max ampdu rcv size to 64k for all 11n
         * devices except 4321A0 and 4321A1
         */
        if (BRCMS_ISNPHY(wlc->band) && NREV_LT(wlc->band->phyrev, 2))
                ampdu->rx_factor = IEEE80211_HT_MAX_AMPDU_32K;
        else
                ampdu->rx_factor = IEEE80211_HT_MAX_AMPDU_64K;
        ampdu->retry_limit = AMPDU_DEF_RETRY_LIMIT;
        ampdu->rr_retry_limit = AMPDU_DEF_RR_RETRY_LIMIT;

        for (i = 0; i < AMPDU_MAX_SCB_TID; i++) {
                ampdu->retry_limit_tid[i] = ampdu->retry_limit;
                ampdu->rr_retry_limit_tid[i] = ampdu->rr_retry_limit;
        }

        brcms_c_scb_ampdu_update_max_txlen(ampdu, ampdu->dur);
        ampdu->mfbr = false;
        /* try to set ampdu to the default value */
        brcms_c_ampdu_set(ampdu, wlc->pub->_ampdu);

        ampdu->tx_max_funl = FFPLD_TX_MAX_UNFL;
        brcms_c_ffpld_init(ampdu);

        return ampdu;
}

void brcms_c_ampdu_detach(struct ampdu_info *ampdu)
{
        kfree(ampdu);
}

static void brcms_c_scb_ampdu_update_config(struct ampdu_info *ampdu,
                                            struct scb *scb)
{
        struct scb_ampdu *scb_ampdu = &scb->scb_ampdu;
        int i;

        scb_ampdu->max_pdu = AMPDU_NUM_MPDU;

        /* go back to legacy size if some preloading is occurring */
        for (i = 0; i < NUM_FFPLD_FIFO; i++) {
                if (ampdu->fifo_tb[i].ampdu_pld_size > FFPLD_PLD_INCR)
                        scb_ampdu->max_pdu = AMPDU_NUM_MPDU_LEGACY;
        }

        /* apply user override */
        if (ampdu->max_pdu != AUTO)
                scb_ampdu->max_pdu = (u8) ampdu->max_pdu;

        scb_ampdu->release = min_t(u8, scb_ampdu->max_pdu,
                                   AMPDU_SCB_MAX_RELEASE);

        if (scb_ampdu->max_rx_ampdu_bytes)
                scb_ampdu->release = min_t(u8, scb_ampdu->release,
                        scb_ampdu->max_rx_ampdu_bytes / 1600);

        scb_ampdu->release = min(scb_ampdu->release,
                                 ampdu->fifo_tb[TX_AC_BE_FIFO].
                                 mcs2ampdu_table[FFPLD_MAX_MCS]);
}

static void brcms_c_scb_ampdu_update_config_all(struct ampdu_info *ampdu)
{
        brcms_c_scb_ampdu_update_config(ampdu, &ampdu->wlc->pri_scb);
}

static void brcms_c_ffpld_calc_mcs2ampdu_table(struct ampdu_info *ampdu, int f)
{
        int i;
        u32 phy_rate, dma_rate, tmp;
        u8 max_mpdu;
        struct brcms_fifo_info *fifo = (ampdu->fifo_tb + f);

        /* recompute the dma rate */
        /* note : we divide/multiply by 100 to avoid integer overflows */
        max_mpdu = min_t(u8, fifo->mcs2ampdu_table[FFPLD_MAX_MCS],
                         AMPDU_NUM_MPDU_LEGACY);
        phy_rate = mcs_2_rate(FFPLD_MAX_MCS, true, false);
        dma_rate =
            (((phy_rate / 100) *
              (max_mpdu * FFPLD_MPDU_SIZE - fifo->ampdu_pld_size))
             / (max_mpdu * FFPLD_MPDU_SIZE)) * 100;
        fifo->dmaxferrate = dma_rate;

        /* fill up the mcs2ampdu table; do not recalc the last mcs */
        dma_rate = dma_rate >> 7;
        for (i = 0; i < FFPLD_MAX_MCS; i++) {
                /* shifting to keep it within integer range */
                phy_rate = mcs_2_rate(i, true, false) >> 7;
                if (phy_rate > dma_rate) {
                        tmp = ((fifo->ampdu_pld_size * phy_rate) /
                               ((phy_rate - dma_rate) * FFPLD_MPDU_SIZE)) + 1;
                        tmp = min_t(u32, tmp, 255);
                        fifo->mcs2ampdu_table[i] = (u8) tmp;
                }
        }
}

/* evaluate the dma transfer rate using the tx underflows as feedback.
 * If necessary, increase tx fifo preloading. If not enough,
 * decrease maximum ampdu size for each mcs till underflows stop
 * Return 1 if pre-loading not active, -1 if not an underflow event,
 * 0 if pre-loading module took care of the event.
 */
static int brcms_c_ffpld_check_txfunfl(struct brcms_c_info *wlc, int fid)
{
        struct ampdu_info *ampdu = wlc->ampdu;
        u32 phy_rate = mcs_2_rate(FFPLD_MAX_MCS, true, false);
        u8 max_mpdu;
        u16 max_pld_size;
        u32 new_txunfl;
        struct brcms_fifo_info *fifo = (ampdu->fifo_tb + fid);
        uint xmtfifo_sz;
        u16 cur_txunfl;

        /* return if we got here for a different reason than underflows */
        cur_txunfl = brcms_b_read_shm(wlc->hw,
                                      M_UCODE_MACSTAT +
                                      offsetof(struct macstat, txfunfl[fid]));
        new_txunfl = (u16) (cur_txunfl - fifo->prev_txfunfl);
        if (new_txunfl == 0) {
                brcms_dbg_ht(wlc->hw->d11core,
                             "TX status FRAG set but no tx underflows\n");
                return -1;
        }
        fifo->prev_txfunfl = cur_txunfl;

        if (!ampdu->tx_max_funl)
                return 1;

        /* check if fifo is big enough */
        if (brcms_b_xmtfifo_sz_get(wlc->hw, fid, &xmtfifo_sz))
                return -1;

        if ((TXFIFO_SIZE_UNIT * (u32) xmtfifo_sz) <= ampdu->ffpld_rsvd)
                return 1;

        max_pld_size = TXFIFO_SIZE_UNIT * xmtfifo_sz - ampdu->ffpld_rsvd;
        fifo->accum_txfunfl += new_txunfl;

        /* we need to wait for at least 10 underflows */
        if (fifo->accum_txfunfl < 10)
                return 0;

        brcms_dbg_ht(wlc->hw->d11core, "tx_underflows %d\n", fifo->accum_txfunfl);

        max_mpdu = min_t(u8, fifo->mcs2ampdu_table[FFPLD_MAX_MCS],
                         AMPDU_NUM_MPDU_LEGACY);

        /* In case max value max_pdu is already lower than
           the fifo depth, there is nothing more we can do.
         */

        if (fifo->ampdu_pld_size >= max_mpdu * FFPLD_MPDU_SIZE) {
                fifo->accum_txfunfl = 0;
                return 0;
        }

        if (fifo->ampdu_pld_size < max_pld_size) {

                /* increment by TX_FIFO_PLD_INC bytes */
                fifo->ampdu_pld_size += FFPLD_PLD_INCR;
                if (fifo->ampdu_pld_size > max_pld_size)
                        fifo->ampdu_pld_size = max_pld_size;

                /* update scb release size */
                brcms_c_scb_ampdu_update_config_all(ampdu);

                /*
                 * compute a new dma xfer rate for max_mpdu @ max mcs.
                 * This is the minimum dma rate that can achieve no
                 * underflow condition for the current mpdu size.
                 *
                 * note : we divide/multiply by 100 to avoid integer overflows
                 */
                fifo->dmaxferrate =
                    (((phy_rate / 100) *
                      (max_mpdu * FFPLD_MPDU_SIZE - fifo->ampdu_pld_size))
                     / (max_mpdu * FFPLD_MPDU_SIZE)) * 100;

                brcms_dbg_ht(wlc->hw->d11core,
                             "DMA estimated transfer rate %d; "
                             "pre-load size %d\n",
                             fifo->dmaxferrate, fifo->ampdu_pld_size);
        } else {

                /* decrease ampdu size */
                if (fifo->mcs2ampdu_table[FFPLD_MAX_MCS] > 1) {
                        if (fifo->mcs2ampdu_table[FFPLD_MAX_MCS] == 255)
                                fifo->mcs2ampdu_table[FFPLD_MAX_MCS] =
                                    AMPDU_NUM_MPDU_LEGACY - 1;
                        else
                                fifo->mcs2ampdu_table[FFPLD_MAX_MCS] -= 1;

                        /* recompute the table */
                        brcms_c_ffpld_calc_mcs2ampdu_table(ampdu, fid);

                        /* update scb release size */
                        brcms_c_scb_ampdu_update_config_all(ampdu);
                }
        }
        fifo->accum_txfunfl = 0;
        return 0;
}

void
brcms_c_ampdu_tx_operational(struct brcms_c_info *wlc, u8 tid,
        uint max_rx_ampdu_bytes) /* from ht_cap in beacon */
{
        struct scb_ampdu *scb_ampdu;
        struct ampdu_info *ampdu = wlc->ampdu;
        struct scb *scb = &wlc->pri_scb;
        scb_ampdu = &scb->scb_ampdu;

        if (!ampdu->ini_enable[tid]) {
                brcms_err(wlc->hw->d11core, "%s: Rejecting tid %d\n",
                          __func__, tid);
                return;
        }

        scb_ampdu->max_rx_ampdu_bytes = max_rx_ampdu_bytes;
}

void brcms_c_ampdu_reset_session(struct brcms_ampdu_session *session,
                                 struct brcms_c_info *wlc)
{
        session->wlc = wlc;
        skb_queue_head_init(&session->skb_list);
        session->max_ampdu_len = 0;    /* determined from first MPDU */
        session->max_ampdu_frames = 0; /* determined from first MPDU */
        session->ampdu_len = 0;
        session->dma_len = 0;
}

/*
 * Preps the given packet for AMPDU based on the session data. If the
 * frame cannot be accommodated in the current session, -ENOSPC is
 * returned.
 */
int brcms_c_ampdu_add_frame(struct brcms_ampdu_session *session,
                            struct sk_buff *p)
{
        struct brcms_c_info *wlc = session->wlc;
        struct ampdu_info *ampdu = wlc->ampdu;
        struct scb *scb = &wlc->pri_scb;
        struct scb_ampdu *scb_ampdu = &scb->scb_ampdu;
        struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(p);
        struct ieee80211_tx_rate *txrate = tx_info->status.rates;
        struct d11txh *txh = (struct d11txh *)p->data;
        unsigned ampdu_frames;
        u8 ndelim, tid;
        u8 *plcp;
        uint len;
        u16 mcl;
        bool fbr_iscck;
        bool rr;

        ndelim = txh->RTSPLCPFallback[AMPDU_FBR_NULL_DELIM];
        plcp = (u8 *)(txh + 1);
        fbr_iscck = !(le16_to_cpu(txh->XtraFrameTypes) & 0x03);
        len = fbr_iscck ? BRCMS_GET_CCK_PLCP_LEN(txh->FragPLCPFallback) :
                          BRCMS_GET_MIMO_PLCP_LEN(txh->FragPLCPFallback);
        len = roundup(len, 4) + (ndelim + 1) * AMPDU_DELIMITER_LEN;

        ampdu_frames = skb_queue_len(&session->skb_list);
        if (ampdu_frames != 0) {
                struct sk_buff *first;

                if (ampdu_frames + 1 > session->max_ampdu_frames ||
                    session->ampdu_len + len > session->max_ampdu_len)
                        return -ENOSPC;

                /*
                 * We aren't really out of space if the new frame is of
                 * a different priority, but we want the same behaviour
                 * so return -ENOSPC anyway.
                 *
                 * XXX: The old AMPDU code did this, but is it really
                 * necessary?
                 */
                first = skb_peek(&session->skb_list);
                if (p->priority != first->priority)
                        return -ENOSPC;
        }

        /*
         * Now that we're sure this frame can be accommodated, update the
         * session information.
         */
        session->ampdu_len += len;
        session->dma_len += p->len;

        tid = (u8)p->priority;

        /* Handle retry limits */
        if (txrate[0].count <= ampdu->rr_retry_limit_tid[tid]) {
                txrate[0].count++;
                rr = true;
        } else {
                txrate[1].count++;
                rr = false;
        }

        if (ampdu_frames == 0) {
                u8 plcp0, plcp3, is40, sgi, mcs;
                uint fifo = le16_to_cpu(txh->TxFrameID) & TXFID_QUEUE_MASK;
                struct brcms_fifo_info *f = &ampdu->fifo_tb[fifo];

                if (rr) {
                        plcp0 = plcp[0];
                        plcp3 = plcp[3];
                } else {
                        plcp0 = txh->FragPLCPFallback[0];
                        plcp3 = txh->FragPLCPFallback[3];

                }

                /* Limit AMPDU size based on MCS */
                is40 = (plcp0 & MIMO_PLCP_40MHZ) ? 1 : 0;
                sgi = plcp3_issgi(plcp3) ? 1 : 0;
                mcs = plcp0 & ~MIMO_PLCP_40MHZ;
                session->max_ampdu_len = min(scb_ampdu->max_rx_ampdu_bytes,
                                             ampdu->max_txlen[mcs][is40][sgi]);

                session->max_ampdu_frames = scb_ampdu->max_pdu;
                if (mcs_2_rate(mcs, true, false) >= f->dmaxferrate) {
                        session->max_ampdu_frames =
                                min_t(u16, f->mcs2ampdu_table[mcs],
                                      session->max_ampdu_frames);
                }
        }

        /*
         * Treat all frames as "middle" frames of AMPDU here. First and
         * last frames must be fixed up after all MPDUs have been prepped.
         */
        mcl = le16_to_cpu(txh->MacTxControlLow);
        mcl &= ~TXC_AMPDU_MASK;
        mcl |= (TXC_AMPDU_MIDDLE << TXC_AMPDU_SHIFT);
        mcl &= ~(TXC_STARTMSDU | TXC_SENDRTS | TXC_SENDCTS);
        txh->MacTxControlLow = cpu_to_le16(mcl);
        txh->PreloadSize = 0;   /* always default to 0 */

        skb_queue_tail(&session->skb_list, p);

        return 0;
}

void brcms_c_ampdu_finalize(struct brcms_ampdu_session *session)
{
        struct brcms_c_info *wlc = session->wlc;
        struct ampdu_info *ampdu = wlc->ampdu;
        struct sk_buff *first, *last;
        struct d11txh *txh;
        struct ieee80211_tx_info *tx_info;
        struct ieee80211_tx_rate *txrate;
        u8 ndelim;
        u8 *plcp;
        uint len;
        uint fifo;
        struct brcms_fifo_info *f;
        u16 mcl;
        bool fbr;
        bool fbr_iscck;
        struct ieee80211_rts *rts;
        bool use_rts = false, use_cts = false;
        u16 dma_len = session->dma_len;
        u16 mimo_ctlchbw = PHY_TXC1_BW_20MHZ;
        u32 rspec = 0, rspec_fallback = 0;
        u32 rts_rspec = 0, rts_rspec_fallback = 0;
        u8 plcp0, is40, mcs;
        u16 mch;
        u8 preamble_type = BRCMS_GF_PREAMBLE;
        u8 fbr_preamble_type = BRCMS_GF_PREAMBLE;
        u8 rts_preamble_type = BRCMS_LONG_PREAMBLE;
        u8 rts_fbr_preamble_type = BRCMS_LONG_PREAMBLE;

        if (skb_queue_empty(&session->skb_list))
                return;

        first = skb_peek(&session->skb_list);
        last = skb_peek_tail(&session->skb_list);

        /* Need to fix up last MPDU first to adjust AMPDU length */
        txh = (struct d11txh *)last->data;
        fifo = le16_to_cpu(txh->TxFrameID) & TXFID_QUEUE_MASK;
        f = &ampdu->fifo_tb[fifo];

        mcl = le16_to_cpu(txh->MacTxControlLow);
        mcl &= ~TXC_AMPDU_MASK;
        mcl |= (TXC_AMPDU_LAST << TXC_AMPDU_SHIFT);
        txh->MacTxControlLow = cpu_to_le16(mcl);

        /* remove the null delimiter after last mpdu */
        ndelim = txh->RTSPLCPFallback[AMPDU_FBR_NULL_DELIM];
        txh->RTSPLCPFallback[AMPDU_FBR_NULL_DELIM] = 0;
        session->ampdu_len -= ndelim * AMPDU_DELIMITER_LEN;

        /* remove the pad len from last mpdu */
        fbr_iscck = ((le16_to_cpu(txh->XtraFrameTypes) & 0x3) == 0);
        len = fbr_iscck ? BRCMS_GET_CCK_PLCP_LEN(txh->FragPLCPFallback) :
                          BRCMS_GET_MIMO_PLCP_LEN(txh->FragPLCPFallback);
        session->ampdu_len -= roundup(len, 4) - len;

        /* Now fix up the first MPDU */
        tx_info = IEEE80211_SKB_CB(first);
        txrate = tx_info->status.rates;
        txh = (struct d11txh *)first->data;
        plcp = (u8 *)(txh + 1);
        rts = (struct ieee80211_rts *)&txh->rts_frame;

        mcl = le16_to_cpu(txh->MacTxControlLow);
        /* If only one MPDU leave it marked as last */
        if (first != last) {
                mcl &= ~TXC_AMPDU_MASK;
                mcl |= (TXC_AMPDU_FIRST << TXC_AMPDU_SHIFT);
        }
        mcl |= TXC_STARTMSDU;
        if (ieee80211_is_rts(rts->frame_control)) {
                mcl |= TXC_SENDRTS;
                use_rts = true;
        }
        if (ieee80211_is_cts(rts->frame_control)) {
                mcl |= TXC_SENDCTS;
                use_cts = true;
        }
        txh->MacTxControlLow = cpu_to_le16(mcl);

        fbr = txrate[1].count > 0;
        if (!fbr)
                plcp0 = plcp[0];
        else
                plcp0 = txh->FragPLCPFallback[0];

        is40 = (plcp0 & MIMO_PLCP_40MHZ) ? 1 : 0;
        mcs = plcp0 & ~MIMO_PLCP_40MHZ;

        if (is40) {
                if (CHSPEC_SB_UPPER(wlc_phy_chanspec_get(wlc->band->pi)))
                        mimo_ctlchbw = PHY_TXC1_BW_20MHZ_UP;
                else
                        mimo_ctlchbw = PHY_TXC1_BW_20MHZ;
        }

        /* rebuild the rspec and rspec_fallback */
        rspec = RSPEC_MIMORATE;
        rspec |= plcp[0] & ~MIMO_PLCP_40MHZ;
        if (plcp[0] & MIMO_PLCP_40MHZ)
                rspec |= (PHY_TXC1_BW_40MHZ << RSPEC_BW_SHIFT);

        fbr_iscck = !(le16_to_cpu(txh->XtraFrameTypes) & 0x03);
        if (fbr_iscck) {
                rspec_fallback =
                        cck_rspec(cck_phy2mac_rate(txh->FragPLCPFallback[0]));
        } else {
                rspec_fallback = RSPEC_MIMORATE;
                rspec_fallback |= txh->FragPLCPFallback[0] & ~MIMO_PLCP_40MHZ;
                if (txh->FragPLCPFallback[0] & MIMO_PLCP_40MHZ)
                        rspec_fallback |= PHY_TXC1_BW_40MHZ << RSPEC_BW_SHIFT;
        }

        if (use_rts || use_cts) {
                rts_rspec =
                        brcms_c_rspec_to_rts_rspec(wlc, rspec,
                                                   false, mimo_ctlchbw);
                rts_rspec_fallback =
                        brcms_c_rspec_to_rts_rspec(wlc, rspec_fallback,
                                                   false, mimo_ctlchbw);
        }

        BRCMS_SET_MIMO_PLCP_LEN(plcp, session->ampdu_len);
        /* mark plcp to indicate ampdu */
        BRCMS_SET_MIMO_PLCP_AMPDU(plcp);

        /* reset the mixed mode header durations */
        if (txh->MModeLen) {
                u16 mmodelen = brcms_c_calc_lsig_len(wlc, rspec,
                                                     session->ampdu_len);
                txh->MModeLen = cpu_to_le16(mmodelen);
                preamble_type = BRCMS_MM_PREAMBLE;
        }
        if (txh->MModeFbrLen) {
                u16 mmfbrlen = brcms_c_calc_lsig_len(wlc, rspec_fallback,
                                                     session->ampdu_len);
                txh->MModeFbrLen = cpu_to_le16(mmfbrlen);
                fbr_preamble_type = BRCMS_MM_PREAMBLE;
        }

        /* set the preload length */
        if (mcs_2_rate(mcs, true, false) >= f->dmaxferrate) {
                dma_len = min(dma_len, f->ampdu_pld_size);
                txh->PreloadSize = cpu_to_le16(dma_len);
        } else {
                txh->PreloadSize = 0;
        }

        mch = le16_to_cpu(txh->MacTxControlHigh);

        /* update RTS dur fields */
        if (use_rts || use_cts) {
                u16 durid;
                if ((mch & TXC_PREAMBLE_RTS_MAIN_SHORT) ==
                    TXC_PREAMBLE_RTS_MAIN_SHORT)
                        rts_preamble_type = BRCMS_SHORT_PREAMBLE;

                if ((mch & TXC_PREAMBLE_RTS_FB_SHORT) ==
                     TXC_PREAMBLE_RTS_FB_SHORT)
                        rts_fbr_preamble_type = BRCMS_SHORT_PREAMBLE;

                durid = brcms_c_compute_rtscts_dur(wlc, use_cts, rts_rspec,
                                                   rspec, rts_preamble_type,
                                                   preamble_type,
                                                   session->ampdu_len, true);
                rts->duration = cpu_to_le16(durid);
                durid = brcms_c_compute_rtscts_dur(wlc, use_cts,
                                                   rts_rspec_fallback,
                                                   rspec_fallback,
                                                   rts_fbr_preamble_type,
                                                   fbr_preamble_type,
                                                   session->ampdu_len, true);
                txh->RTSDurFallback = cpu_to_le16(durid);
                /* set TxFesTimeNormal */
                txh->TxFesTimeNormal = rts->duration;
                /* set fallback rate version of TxFesTimeNormal */
                txh->TxFesTimeFallback = txh->RTSDurFallback;
        }

        /* set flag and plcp for fallback rate */
        if (fbr) {
                mch |= TXC_AMPDU_FBR;
                txh->MacTxControlHigh = cpu_to_le16(mch);
                BRCMS_SET_MIMO_PLCP_AMPDU(plcp);
                BRCMS_SET_MIMO_PLCP_AMPDU(txh->FragPLCPFallback);
        }

        brcms_dbg_ht(wlc->hw->d11core, "wl%d: count %d ampdu_len %d\n",
                     wlc->pub->unit, skb_queue_len(&session->skb_list),
                     session->ampdu_len);
}

static void
brcms_c_ampdu_rate_status(struct brcms_c_info *wlc,
                          struct ieee80211_tx_info *tx_info,
                          struct tx_status *txs, u8 mcs)
{
        struct ieee80211_tx_rate *txrate = tx_info->status.rates;
        int i;

        /* clear the rest of the rates */
        for (i = 2; i < IEEE80211_TX_MAX_RATES; i++) {
                txrate[i].idx = -1;
                txrate[i].count = 0;
        }
}

static void
brcms_c_ampdu_dotxstatus_complete(struct ampdu_info *ampdu, struct scb *scb,
                              struct sk_buff *p, struct tx_status *txs,
                              u32 s1, u32 s2)
{
        struct scb_ampdu *scb_ampdu;
        struct brcms_c_info *wlc = ampdu->wlc;
        struct scb_ampdu_tid_ini *ini;
        u8 bitmap[8], queue, tid;
        struct d11txh *txh;
        u8 *plcp;
        struct ieee80211_hdr *h;
        u16 seq, start_seq = 0, bindex, index, mcl;
        u8 mcs = 0;
        bool ba_recd = false, ack_recd = false;
        u8 tot_mpdu = 0;
        uint supr_status;
        bool retry = true;
        u16 mimoantsel = 0;
        u8 retry_limit;
        struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(p);

#ifdef DEBUG
        u8 hole[AMPDU_MAX_MPDU];
        memset(hole, 0, sizeof(hole));
#endif

        scb_ampdu = &scb->scb_ampdu;
        tid = (u8) (p->priority);

        ini = &scb_ampdu->ini[tid];
        retry_limit = ampdu->retry_limit_tid[tid];
        memset(bitmap, 0, sizeof(bitmap));
        queue = txs->frameid & TXFID_QUEUE_MASK;
        supr_status = txs->status & TX_STATUS_SUPR_MASK;

        if (txs->status & TX_STATUS_ACK_RCV) {
                WARN_ON(!(txs->status & TX_STATUS_INTERMEDIATE));
                start_seq = txs->sequence >> SEQNUM_SHIFT;
                bitmap[0] = (txs->status & TX_STATUS_BA_BMAP03_MASK) >>
                    TX_STATUS_BA_BMAP03_SHIFT;

                WARN_ON(s1 & TX_STATUS_INTERMEDIATE);
                WARN_ON(!(s1 & TX_STATUS_AMPDU));

                bitmap[0] |=
                    (s1 & TX_STATUS_BA_BMAP47_MASK) <<
                    TX_STATUS_BA_BMAP47_SHIFT;
                bitmap[1] = (s1 >> 8) & 0xff;
                bitmap[2] = (s1 >> 16) & 0xff;
                bitmap[3] = (s1 >> 24) & 0xff;

                bitmap[4] = s2 & 0xff;
                bitmap[5] = (s2 >> 8) & 0xff;
                bitmap[6] = (s2 >> 16) & 0xff;
                bitmap[7] = (s2 >> 24) & 0xff;

                ba_recd = true;
        } else {
                if (supr_status) {
                        if (supr_status == TX_STATUS_SUPR_BADCH) {
                                brcms_dbg_ht(wlc->hw->d11core,
                                          "%s: Pkt tx suppressed, illegal channel possibly %d\n",
                                          __func__, CHSPEC_CHANNEL(
                                          wlc->default_bss->chanspec));
                        } else {
                                if (supr_status != TX_STATUS_SUPR_FRAG)
                                        brcms_err(wlc->hw->d11core,
                                                  "%s: supr_status 0x%x\n",
                                                  __func__, supr_status);
                        }
                        /* no need to retry for badch; will fail again */
                        if (supr_status == TX_STATUS_SUPR_BADCH ||
                            supr_status == TX_STATUS_SUPR_EXPTIME) {
                                retry = false;
                        } else if (supr_status == TX_STATUS_SUPR_EXPTIME) {
                                /* TX underflow:
                                 *   try tuning pre-loading or ampdu size
                                 */
                        } else if (supr_status == TX_STATUS_SUPR_FRAG) {
                                /*
                                 * if there were underflows, but pre-loading
                                 * is not active, notify rate adaptation.
                                 */
                                brcms_c_ffpld_check_txfunfl(wlc, queue);
                        }
                } else if (txs->phyerr) {
                        brcms_dbg_ht(wlc->hw->d11core,
                                     "%s: ampdu tx phy error (0x%x)\n",
                                     __func__, txs->phyerr);
                }
        }

        /* loop through all pkts and retry if not acked */
        while (p) {
                tx_info = IEEE80211_SKB_CB(p);
                txh = (struct d11txh *) p->data;
                mcl = le16_to_cpu(txh->MacTxControlLow);
                plcp = (u8 *) (txh + 1);
                h = (struct ieee80211_hdr *)(plcp + D11_PHY_HDR_LEN);
                seq = le16_to_cpu(h->seq_ctrl) >> SEQNUM_SHIFT;

                trace_brcms_txdesc(&wlc->hw->d11core->dev, txh, sizeof(*txh));

                if (tot_mpdu == 0) {
                        mcs = plcp[0] & MIMO_PLCP_MCS_MASK;
                        mimoantsel = le16_to_cpu(txh->ABI_MimoAntSel);
                }

                index = TX_SEQ_TO_INDEX(seq);
                ack_recd = false;
                if (ba_recd) {
                        int block_acked;

                        bindex = MODSUB_POW2(seq, start_seq, SEQNUM_MAX);
                        if (bindex < AMPDU_TX_BA_MAX_WSIZE)
                                block_acked = isset(bitmap, bindex);
                        else
                                block_acked = 0;
                        brcms_dbg_ht(wlc->hw->d11core,
                                     "tid %d seq %d, start_seq %d, bindex %d set %d, index %d\n",
                                     tid, seq, start_seq, bindex,
                                     block_acked, index);
                        /* if acked then clear bit and free packet */
                        if (block_acked) {
                                ini->txretry[index] = 0;

                                /*
                                 * ampdu_ack_len:
                                 *   number of acked aggregated frames
                                 */
                                /* ampdu_len: number of aggregated frames */
                                brcms_c_ampdu_rate_status(wlc, tx_info, txs,
                                                          mcs);
                                tx_info->flags |= IEEE80211_TX_STAT_ACK;
                                tx_info->flags |= IEEE80211_TX_STAT_AMPDU;
                                tx_info->status.ampdu_ack_len =
                                        tx_info->status.ampdu_len = 1;

                                skb_pull(p, D11_PHY_HDR_LEN);
                                skb_pull(p, D11_TXH_LEN);

                                ieee80211_tx_status_irqsafe(wlc->pub->ieee_hw,
                                                            p);
                                ack_recd = true;
                        }
                }
                /* either retransmit or send bar if ack not recd */
                if (!ack_recd) {
                        if (retry && (ini->txretry[index] < (int)retry_limit)) {
                                int ret;
                                ini->txretry[index]++;
                                ret = brcms_c_txfifo(wlc, queue, p);
                                /*
                                 * We shouldn't be out of space in the DMA
                                 * ring here since we're reinserting a frame
                                 * that was just pulled out.
                                 */
                                WARN_ONCE(ret, "queue %d out of txds\n", queue);
                        } else {
                                /* Retry timeout */
                                ieee80211_tx_info_clear_status(tx_info);
                                tx_info->status.ampdu_ack_len = 0;
                                tx_info->status.ampdu_len = 1;
                                tx_info->flags |=
                                    IEEE80211_TX_STAT_AMPDU_NO_BACK;
                                skb_pull(p, D11_PHY_HDR_LEN);
                                skb_pull(p, D11_TXH_LEN);
                                brcms_dbg_ht(wlc->hw->d11core,
                                             "BA Timeout, seq %d\n",
                                             seq);
                                ieee80211_tx_status_irqsafe(wlc->pub->ieee_hw,
                                                            p);
                        }
                }
                tot_mpdu++;

                /* break out if last packet of ampdu */
                if (((mcl & TXC_AMPDU_MASK) >> TXC_AMPDU_SHIFT) ==
                    TXC_AMPDU_LAST)
                        break;

                p = dma_getnexttxp(wlc->hw->di[queue], DMA_RANGE_TRANSMITTED);
        }

        /* update rate state */
        brcms_c_antsel_antsel2id(wlc->asi, mimoantsel);
}

void
brcms_c_ampdu_dotxstatus(struct ampdu_info *ampdu, struct scb *scb,
                     struct sk_buff *p, struct tx_status *txs)
{
        struct brcms_c_info *wlc = ampdu->wlc;
        u32 s1 = 0, s2 = 0;

        /* BMAC_NOTE: For the split driver, second level txstatus comes later
         * So if the ACK was received then wait for the second level else just
         * call the first one
         */
        if (txs->status & TX_STATUS_ACK_RCV) {
                u8 status_delay = 0;

                /* wait till the next 8 bytes of txstatus is available */
                s1 = bcma_read32(wlc->hw->d11core, D11REGOFFS(frmtxstatus));
                while ((s1 & TXS_V) == 0) {
                        udelay(1);
                        status_delay++;
                        if (status_delay > 10)
                                return; /* error condition */
                        s1 = bcma_read32(wlc->hw->d11core,
                                         D11REGOFFS(frmtxstatus));
                }

                s2 = bcma_read32(wlc->hw->d11core, D11REGOFFS(frmtxstatus2));
        }

        if (scb) {
                brcms_c_ampdu_dotxstatus_complete(ampdu, scb, p, txs, s1, s2);
        } else {
                /* loop through all pkts and free */
                u8 queue = txs->frameid & TXFID_QUEUE_MASK;
                struct d11txh *txh;
                u16 mcl;
                while (p) {
                        txh = (struct d11txh *) p->data;
                        trace_brcms_txdesc(&wlc->hw->d11core->dev, txh,
                                           sizeof(*txh));
                        mcl = le16_to_cpu(txh->MacTxControlLow);
                        brcmu_pkt_buf_free_skb(p);
                        /* break out if last packet of ampdu */
                        if (((mcl & TXC_AMPDU_MASK) >> TXC_AMPDU_SHIFT) ==
                            TXC_AMPDU_LAST)
                                break;
                        p = dma_getnexttxp(wlc->hw->di[queue],
                                           DMA_RANGE_TRANSMITTED);
                }
        }
}

void brcms_c_ampdu_macaddr_upd(struct brcms_c_info *wlc)
{
        char template[T_RAM_ACCESS_SZ * 2];

        /* driver needs to write the ta in the template; ta is at offset 16 */
        memset(template, 0, sizeof(template));
        memcpy(template, wlc->pub->cur_etheraddr, ETH_ALEN);
        brcms_b_write_template_ram(wlc->hw, (T_BA_TPL_BASE + 16),
                                  (T_RAM_ACCESS_SZ * 2),
                                  template);
}

bool brcms_c_aggregatable(struct brcms_c_info *wlc, u8 tid)
{
        return wlc->ampdu->ini_enable[tid];
}

void brcms_c_ampdu_shm_upd(struct ampdu_info *ampdu)
{
        struct brcms_c_info *wlc = ampdu->wlc;

        /*
         * Extend ucode internal watchdog timer to
         * match larger received frames
         */
        if ((ampdu->rx_factor & IEEE80211_HT_AMPDU_PARM_FACTOR) ==
            IEEE80211_HT_MAX_AMPDU_64K) {
                brcms_b_write_shm(wlc->hw, M_MIMO_MAXSYM, MIMO_MAXSYM_MAX);
                brcms_b_write_shm(wlc->hw, M_WATCHDOG_8TU, WATCHDOG_8TU_MAX);
        } else {
                brcms_b_write_shm(wlc->hw, M_MIMO_MAXSYM, MIMO_MAXSYM_DEF);
                brcms_b_write_shm(wlc->hw, M_WATCHDOG_8TU, WATCHDOG_8TU_DEF);
        }
}

/*
 * callback function that helps invalidating ampdu packets in a DMA queue
 */
static void dma_cb_fn_ampdu(void *txi, void *arg_a)
{
        struct ieee80211_sta *sta = arg_a;
        struct ieee80211_tx_info *tx_info = (struct ieee80211_tx_info *)txi;

        if ((tx_info->flags & IEEE80211_TX_CTL_AMPDU) &&
            (tx_info->rate_driver_data[0] == sta || sta == NULL))
                tx_info->rate_driver_data[0] = NULL;
}

/*
 * When a remote party is no longer available for ampdu communication, any
 * pending tx ampdu packets in the driver have to be flushed.
 */
void brcms_c_ampdu_flush(struct brcms_c_info *wlc,
                     struct ieee80211_sta *sta, u16 tid)
{
        brcms_c_inval_dma_pkts(wlc->hw, sta, dma_cb_fn_ampdu);
}