/******************************************************************************
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
 * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
 * Copyright(c) 2015 - 2017 Intel Deutschland GmbH
 *
 * 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.
 *
 * The full GNU General Public License is included in this distribution
 * in the file called COPYING.
 *
 * Contact Information:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 * BSD LICENSE
 *
 * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
 * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
 * Copyright(c) 2015 - 2017 Intel Deutschland GmbH
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include "iwl-trans.h"
#include "mvm.h"
#include "fw-api.h"

static inline int iwl_mvm_check_pn(struct iwl_mvm *mvm, struct sk_buff *skb,
                                   int queue, struct ieee80211_sta *sta)
{
        struct iwl_mvm_sta *mvmsta;
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
        struct ieee80211_rx_status *stats = IEEE80211_SKB_RXCB(skb);
        struct iwl_mvm_key_pn *ptk_pn;
        u8 tid, keyidx;
        u8 pn[IEEE80211_CCMP_PN_LEN];
        u8 *extiv;

        /* do PN checking */

        /* multicast and non-data only arrives on default queue */
        if (!ieee80211_is_data(hdr->frame_control) ||
            is_multicast_ether_addr(hdr->addr1))
                return 0;

        /* do not check PN for open AP */
        if (!(stats->flag & RX_FLAG_DECRYPTED))
                return 0;

        /*
         * avoid checking for default queue - we don't want to replicate
         * all the logic that's necessary for checking the PN on fragmented
         * frames, leave that to mac80211
         */
        if (queue == 0)
                return 0;

        /* if we are here - this for sure is either CCMP or GCMP */
        if (IS_ERR_OR_NULL(sta)) {
                IWL_ERR(mvm,
                        "expected hw-decrypted unicast frame for station\n");
                return -1;
        }

        mvmsta = iwl_mvm_sta_from_mac80211(sta);

        extiv = (u8 *)hdr + ieee80211_hdrlen(hdr->frame_control);
        keyidx = extiv[3] >> 6;

        ptk_pn = rcu_dereference(mvmsta->ptk_pn[keyidx]);
        if (!ptk_pn)
                return -1;

        if (ieee80211_is_data_qos(hdr->frame_control))
                tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
        else
                tid = 0;

        /* we don't use HCCA/802.11 QoS TSPECs, so drop such frames */
        if (tid >= IWL_MAX_TID_COUNT)
                return -1;

        /* load pn */
        pn[0] = extiv[7];
        pn[1] = extiv[6];
        pn[2] = extiv[5];
        pn[3] = extiv[4];
        pn[4] = extiv[1];
        pn[5] = extiv[0];

        if (memcmp(pn, ptk_pn->q[queue].pn[tid],
                   IEEE80211_CCMP_PN_LEN) <= 0)
                return -1;

        if (!(stats->flag & RX_FLAG_AMSDU_MORE))
                memcpy(ptk_pn->q[queue].pn[tid], pn, IEEE80211_CCMP_PN_LEN);
        stats->flag |= RX_FLAG_PN_VALIDATED;

        return 0;
}

/* iwl_mvm_create_skb Adds the rxb to a new skb */
static void iwl_mvm_create_skb(struct sk_buff *skb, struct ieee80211_hdr *hdr,
                               u16 len, u8 crypt_len,
                               struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_rx_mpdu_desc *desc = (void *)pkt->data;
        unsigned int headlen, fraglen, pad_len = 0;
        unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);

        if (desc->mac_flags2 & IWL_RX_MPDU_MFLG2_PAD) {
                pad_len = 2;

                /*
                 * If the device inserted padding it means that (it thought)
                 * the 802.11 header wasn't a multiple of 4 bytes long. In
                 * this case, reserve two bytes at the start of the SKB to
                 * align the payload properly in case we end up copying it.
                 */
                skb_reserve(skb, pad_len);
        }
        len -= pad_len;

        /* If frame is small enough to fit in skb->head, pull it completely.
         * If not, only pull ieee80211_hdr (including crypto if present, and
         * an additional 8 bytes for SNAP/ethertype, see below) so that
         * splice() or TCP coalesce are more efficient.
         *
         * Since, in addition, ieee80211_data_to_8023() always pull in at
         * least 8 bytes (possibly more for mesh) we can do the same here
         * to save the cost of doing it later. That still doesn't pull in
         * the actual IP header since the typical case has a SNAP header.
         * If the latter changes (there are efforts in the standards group
         * to do so) we should revisit this and ieee80211_data_to_8023().
         */
        headlen = (len <= skb_tailroom(skb)) ? len :
                                               hdrlen + crypt_len + 8;

        /* The firmware may align the packet to DWORD.
         * The padding is inserted after the IV.
         * After copying the header + IV skip the padding if
         * present before copying packet data.
         */
        hdrlen += crypt_len;
        skb_put_data(skb, hdr, hdrlen);
        skb_put_data(skb, (u8 *)hdr + hdrlen + pad_len, headlen - hdrlen);

        fraglen = len - headlen;

        if (fraglen) {
                int offset = (void *)hdr + headlen + pad_len -
                             rxb_addr(rxb) + rxb_offset(rxb);

                skb_add_rx_frag(skb, 0, rxb_steal_page(rxb), offset,
                                fraglen, rxb->truesize);
        }
}

/* iwl_mvm_pass_packet_to_mac80211 - passes the packet for mac80211 */
static void iwl_mvm_pass_packet_to_mac80211(struct iwl_mvm *mvm,
                                            struct napi_struct *napi,
                                            struct sk_buff *skb, int queue,
                                            struct ieee80211_sta *sta)
{
        if (iwl_mvm_check_pn(mvm, skb, queue, sta))
                kfree_skb(skb);
        else
                ieee80211_rx_napi(mvm->hw, sta, skb, napi);
}

static void iwl_mvm_get_signal_strength(struct iwl_mvm *mvm,
                                        struct iwl_rx_mpdu_desc *desc,
                                        struct ieee80211_rx_status *rx_status)
{
        int energy_a, energy_b, max_energy;

        energy_a = desc->energy_a;
        energy_a = energy_a ? -energy_a : S8_MIN;
        energy_b = desc->energy_b;
        energy_b = energy_b ? -energy_b : S8_MIN;
        max_energy = max(energy_a, energy_b);

        IWL_DEBUG_STATS(mvm, "energy In A %d B %d, and max %d\n",
                        energy_a, energy_b, max_energy);

        rx_status->signal = max_energy;
        rx_status->chains = 0; /* TODO: phy info */
        rx_status->chain_signal[0] = energy_a;
        rx_status->chain_signal[1] = energy_b;
        rx_status->chain_signal[2] = S8_MIN;
}

static int iwl_mvm_rx_crypto(struct iwl_mvm *mvm, struct ieee80211_hdr *hdr,
                             struct ieee80211_rx_status *stats,
                             struct iwl_rx_mpdu_desc *desc, int queue,
                             u8 *crypt_len)
{
        u16 status = le16_to_cpu(desc->status);

        if (!ieee80211_has_protected(hdr->frame_control) ||
            (status & IWL_RX_MPDU_STATUS_SEC_MASK) ==
            IWL_RX_MPDU_STATUS_SEC_NONE)
                return 0;

        /* TODO: handle packets encrypted with unknown alg */

        switch (status & IWL_RX_MPDU_STATUS_SEC_MASK) {
        case IWL_RX_MPDU_STATUS_SEC_CCM:
        case IWL_RX_MPDU_STATUS_SEC_GCM:
                BUILD_BUG_ON(IEEE80211_CCMP_PN_LEN != IEEE80211_GCMP_PN_LEN);
                /* alg is CCM: check MIC only */
                if (!(status & IWL_RX_MPDU_STATUS_MIC_OK))
                        return -1;

                stats->flag |= RX_FLAG_DECRYPTED;
                *crypt_len = IEEE80211_CCMP_HDR_LEN;
                return 0;
        case IWL_RX_MPDU_STATUS_SEC_TKIP:
                /* Don't drop the frame and decrypt it in SW */
                if (!(status & IWL_RX_MPDU_RES_STATUS_TTAK_OK))
                        return 0;

                *crypt_len = IEEE80211_TKIP_IV_LEN;
                /* fall through if TTAK OK */
        case IWL_RX_MPDU_STATUS_SEC_WEP:
                if (!(status & IWL_RX_MPDU_STATUS_ICV_OK))
                        return -1;

                stats->flag |= RX_FLAG_DECRYPTED;
                if ((status & IWL_RX_MPDU_STATUS_SEC_MASK) ==
                                IWL_RX_MPDU_STATUS_SEC_WEP)
                        *crypt_len = IEEE80211_WEP_IV_LEN;
                return 0;
        case IWL_RX_MPDU_STATUS_SEC_EXT_ENC:
                if (!(status & IWL_RX_MPDU_STATUS_MIC_OK))
                        return -1;
                stats->flag |= RX_FLAG_DECRYPTED;
                return 0;
        default:
                /* Expected in monitor (not having the keys) */
                if (!mvm->monitor_on)
                        IWL_ERR(mvm, "Unhandled alg: 0x%x\n", status);
        }

        return 0;
}

static void iwl_mvm_rx_csum(struct ieee80211_sta *sta,
                            struct sk_buff *skb,
                            struct iwl_rx_mpdu_desc *desc)
{
        struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(mvmsta->vif);
        u16 flags = le16_to_cpu(desc->l3l4_flags);
        u8 l3_prot = (u8)((flags & IWL_RX_L3L4_L3_PROTO_MASK) >>
                          IWL_RX_L3_PROTO_POS);

        if (mvmvif->features & NETIF_F_RXCSUM &&
            flags & IWL_RX_L3L4_TCP_UDP_CSUM_OK &&
            (flags & IWL_RX_L3L4_IP_HDR_CSUM_OK ||
             l3_prot == IWL_RX_L3_TYPE_IPV6 ||
             l3_prot == IWL_RX_L3_TYPE_IPV6_FRAG))
                skb->ip_summed = CHECKSUM_UNNECESSARY;
}

/*
 * returns true if a packet outside BA session is a duplicate and
 * should be dropped
 */
static bool iwl_mvm_is_nonagg_dup(struct ieee80211_sta *sta, int queue,
                                  struct ieee80211_rx_status *rx_status,
                                  struct ieee80211_hdr *hdr,
                                  struct iwl_rx_mpdu_desc *desc)
{
        struct iwl_mvm_sta *mvm_sta;
        struct iwl_mvm_rxq_dup_data *dup_data;
        u8 baid, tid, sub_frame_idx;

        if (WARN_ON(IS_ERR_OR_NULL(sta)))
                return false;

        baid = (le32_to_cpu(desc->reorder_data) &
                IWL_RX_MPDU_REORDER_BAID_MASK) >>
                IWL_RX_MPDU_REORDER_BAID_SHIFT;

        if (baid != IWL_RX_REORDER_DATA_INVALID_BAID)
                return false;

        mvm_sta = iwl_mvm_sta_from_mac80211(sta);
        dup_data = &mvm_sta->dup_data[queue];

        /*
         * Drop duplicate 802.11 retransmissions
         * (IEEE 802.11-2012: 9.3.2.10 "Duplicate detection and recovery")
         */
        if (ieee80211_is_ctl(hdr->frame_control) ||
            ieee80211_is_qos_nullfunc(hdr->frame_control) ||
            is_multicast_ether_addr(hdr->addr1)) {
                rx_status->flag |= RX_FLAG_DUP_VALIDATED;
                return false;
        }

        if (ieee80211_is_data_qos(hdr->frame_control))
                /* frame has qos control */
                tid = *ieee80211_get_qos_ctl(hdr) &
                        IEEE80211_QOS_CTL_TID_MASK;
        else
                tid = IWL_MAX_TID_COUNT;

        /* If this wasn't a part of an A-MSDU the sub-frame index will be 0 */
        sub_frame_idx = desc->amsdu_info & IWL_RX_MPDU_AMSDU_SUBFRAME_IDX_MASK;

        if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
                     dup_data->last_seq[tid] == hdr->seq_ctrl &&
                     dup_data->last_sub_frame[tid] >= sub_frame_idx))
                return true;

        dup_data->last_seq[tid] = hdr->seq_ctrl;
        dup_data->last_sub_frame[tid] = sub_frame_idx;

        rx_status->flag |= RX_FLAG_DUP_VALIDATED;

        return false;
}

int iwl_mvm_notify_rx_queue(struct iwl_mvm *mvm, u32 rxq_mask,
                            const u8 *data, u32 count)
{
        struct iwl_rxq_sync_cmd *cmd;
        u32 data_size = sizeof(*cmd) + count;
        int ret;

        /* should be DWORD aligned */
        if (WARN_ON(count & 3 || count > IWL_MULTI_QUEUE_SYNC_MSG_MAX_SIZE))
                return -EINVAL;

        cmd = kzalloc(data_size, GFP_KERNEL);
        if (!cmd)
                return -ENOMEM;

        cmd->rxq_mask = cpu_to_le32(rxq_mask);
        cmd->count =  cpu_to_le32(count);
        cmd->flags = 0;
        memcpy(cmd->payload, data, count);

        ret = iwl_mvm_send_cmd_pdu(mvm,
                                   WIDE_ID(DATA_PATH_GROUP,
                                           TRIGGER_RX_QUEUES_NOTIF_CMD),
                                   0, data_size, cmd);

        kfree(cmd);
        return ret;
}

/*
 * Returns true if sn2 - buffer_size < sn1 < sn2.
 * To be used only in order to compare reorder buffer head with NSSN.
 * We fully trust NSSN unless it is behind us due to reorder timeout.
 * Reorder timeout can only bring us up to buffer_size SNs ahead of NSSN.
 */
static bool iwl_mvm_is_sn_less(u16 sn1, u16 sn2, u16 buffer_size)
{
        return ieee80211_sn_less(sn1, sn2) &&
               !ieee80211_sn_less(sn1, sn2 - buffer_size);
}

#define RX_REORDER_BUF_TIMEOUT_MQ (HZ / 10)

static void iwl_mvm_release_frames(struct iwl_mvm *mvm,
                                   struct ieee80211_sta *sta,
                                   struct napi_struct *napi,
                                   struct iwl_mvm_reorder_buffer *reorder_buf,
                                   u16 nssn)
{
        u16 ssn = reorder_buf->head_sn;

        lockdep_assert_held(&reorder_buf->lock);

        /* ignore nssn smaller than head sn - this can happen due to timeout */
        if (iwl_mvm_is_sn_less(nssn, ssn, reorder_buf->buf_size))
                goto set_timer;

        while (iwl_mvm_is_sn_less(ssn, nssn, reorder_buf->buf_size)) {
                int index = ssn % reorder_buf->buf_size;
                struct sk_buff_head *skb_list = &reorder_buf->entries[index];
                struct sk_buff *skb;

                ssn = ieee80211_sn_inc(ssn);

                /*
                 * Empty the list. Will have more than one frame for A-MSDU.
                 * Empty list is valid as well since nssn indicates frames were
                 * received.
                 */
                while ((skb = __skb_dequeue(skb_list))) {
                        iwl_mvm_pass_packet_to_mac80211(mvm, napi, skb,
                                                        reorder_buf->queue,
                                                        sta);
                        reorder_buf->num_stored--;
                }
        }
        reorder_buf->head_sn = nssn;

set_timer:
        if (reorder_buf->num_stored && !reorder_buf->removed) {
                u16 index = reorder_buf->head_sn % reorder_buf->buf_size;

                while (skb_queue_empty(&reorder_buf->entries[index]))
                        index = (index + 1) % reorder_buf->buf_size;
                /* modify timer to match next frame's expiration time */
                mod_timer(&reorder_buf->reorder_timer,
                          reorder_buf->reorder_time[index] + 1 +
                          RX_REORDER_BUF_TIMEOUT_MQ);
        } else {
                del_timer(&reorder_buf->reorder_timer);
        }
}

void iwl_mvm_reorder_timer_expired(unsigned long data)
{
        struct iwl_mvm_reorder_buffer *buf = (void *)data;
        int i;
        u16 sn = 0, index = 0;
        bool expired = false;
        bool cont = false;

        spin_lock(&buf->lock);

        if (!buf->num_stored || buf->removed) {
                spin_unlock(&buf->lock);
                return;
        }

        for (i = 0; i < buf->buf_size ; i++) {
                index = (buf->head_sn + i) % buf->buf_size;

                if (skb_queue_empty(&buf->entries[index])) {
                        /*
                         * If there is a hole and the next frame didn't expire
                         * we want to break and not advance SN
                         */
                        cont = false;
                        continue;
                }
                if (!cont && !time_after(jiffies, buf->reorder_time[index] +
                                         RX_REORDER_BUF_TIMEOUT_MQ))
                        break;

                expired = true;
                /* continue until next hole after this expired frames */
                cont = true;
                sn = ieee80211_sn_add(buf->head_sn, i + 1);
        }

        if (expired) {
                struct ieee80211_sta *sta;

                rcu_read_lock();
                sta = rcu_dereference(buf->mvm->fw_id_to_mac_id[buf->sta_id]);
                /* SN is set to the last expired frame + 1 */
                IWL_DEBUG_HT(buf->mvm,
                             "Releasing expired frames for sta %u, sn %d\n",
                             buf->sta_id, sn);
                iwl_mvm_release_frames(buf->mvm, sta, NULL, buf, sn);
                rcu_read_unlock();
        } else {
                /*
                 * If no frame expired and there are stored frames, index is now
                 * pointing to the first unexpired frame - modify timer
                 * accordingly to this frame.
                 */
                mod_timer(&buf->reorder_timer,
                          buf->reorder_time[index] +
                          1 + RX_REORDER_BUF_TIMEOUT_MQ);
        }
        spin_unlock(&buf->lock);
}

static void iwl_mvm_del_ba(struct iwl_mvm *mvm, int queue,
                           struct iwl_mvm_delba_data *data)
{
        struct iwl_mvm_baid_data *ba_data;
        struct ieee80211_sta *sta;
        struct iwl_mvm_reorder_buffer *reorder_buf;
        u8 baid = data->baid;

        if (WARN_ONCE(baid >= IWL_MAX_BAID, "invalid BAID: %x\n", baid))
                return;

        rcu_read_lock();

        ba_data = rcu_dereference(mvm->baid_map[baid]);
        if (WARN_ON_ONCE(!ba_data))
                goto out;

        sta = rcu_dereference(mvm->fw_id_to_mac_id[ba_data->sta_id]);
        if (WARN_ON_ONCE(IS_ERR_OR_NULL(sta)))
                goto out;

        reorder_buf = &ba_data->reorder_buf[queue];

        /* release all frames that are in the reorder buffer to the stack */
        spin_lock_bh(&reorder_buf->lock);
        iwl_mvm_release_frames(mvm, sta, NULL, reorder_buf,
                               ieee80211_sn_add(reorder_buf->head_sn,
                                                reorder_buf->buf_size));
        spin_unlock_bh(&reorder_buf->lock);
        del_timer_sync(&reorder_buf->reorder_timer);

out:
        rcu_read_unlock();
}

void iwl_mvm_rx_queue_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
                            int queue)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_rxq_sync_notification *notif;
        struct iwl_mvm_internal_rxq_notif *internal_notif;

        notif = (void *)pkt->data;
        internal_notif = (void *)notif->payload;

        if (internal_notif->sync) {
                if (mvm->queue_sync_cookie != internal_notif->cookie) {
                        WARN_ONCE(1,
                                  "Received expired RX queue sync message\n");
                        return;
                }
                if (!atomic_dec_return(&mvm->queue_sync_counter))
                        wake_up(&mvm->rx_sync_waitq);
        }

        switch (internal_notif->type) {
        case IWL_MVM_RXQ_EMPTY:
                break;
        case IWL_MVM_RXQ_NOTIF_DEL_BA:
                iwl_mvm_del_ba(mvm, queue, (void *)internal_notif->data);
                break;
        default:
                WARN_ONCE(1, "Invalid identifier %d", internal_notif->type);
        }
}

/*
 * Returns true if the MPDU was buffered\dropped, false if it should be passed
 * to upper layer.
 */
static bool iwl_mvm_reorder(struct iwl_mvm *mvm,
                            struct napi_struct *napi,
                            int queue,
                            struct ieee80211_sta *sta,
                            struct sk_buff *skb,
                            struct iwl_rx_mpdu_desc *desc)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
        struct iwl_mvm_sta *mvm_sta;
        struct iwl_mvm_baid_data *baid_data;
        struct iwl_mvm_reorder_buffer *buffer;
        struct sk_buff *tail;
        u32 reorder = le32_to_cpu(desc->reorder_data);
        bool amsdu = desc->mac_flags2 & IWL_RX_MPDU_MFLG2_AMSDU;
        bool last_subframe =
                desc->amsdu_info & IWL_RX_MPDU_AMSDU_LAST_SUBFRAME;
        u8 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
        u8 sub_frame_idx = desc->amsdu_info &
                           IWL_RX_MPDU_AMSDU_SUBFRAME_IDX_MASK;
        int index;
        u16 nssn, sn;
        u8 baid;

        baid = (reorder & IWL_RX_MPDU_REORDER_BAID_MASK) >>
                IWL_RX_MPDU_REORDER_BAID_SHIFT;

        /*
         * This also covers the case of receiving a Block Ack Request
         * outside a BA session; we'll pass it to mac80211 and that
         * then sends a delBA action frame.
         */
        if (baid == IWL_RX_REORDER_DATA_INVALID_BAID)
                return false;

        /* no sta yet */
        if (WARN_ON(IS_ERR_OR_NULL(sta)))
                return false;

        mvm_sta = iwl_mvm_sta_from_mac80211(sta);

        /* not a data packet or a bar */
        if (!ieee80211_is_back_req(hdr->frame_control) &&
            (!ieee80211_is_data_qos(hdr->frame_control) ||
             is_multicast_ether_addr(hdr->addr1)))
                return false;

        if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
                return false;

        baid_data = rcu_dereference(mvm->baid_map[baid]);
        if (!baid_data) {
                IWL_DEBUG_RX(mvm,
                             "Got valid BAID but no baid allocated, bypass the re-ordering buffer. Baid %d reorder 0x%x\n",
                              baid, reorder);
                return false;
        }

        if (WARN(tid != baid_data->tid || mvm_sta->sta_id != baid_data->sta_id,
                 "baid 0x%x is mapped to sta:%d tid:%d, but was received for sta:%d tid:%d\n",
                 baid, baid_data->sta_id, baid_data->tid, mvm_sta->sta_id,
                 tid))
                return false;

        nssn = reorder & IWL_RX_MPDU_REORDER_NSSN_MASK;
        sn = (reorder & IWL_RX_MPDU_REORDER_SN_MASK) >>
                IWL_RX_MPDU_REORDER_SN_SHIFT;

        buffer = &baid_data->reorder_buf[queue];

        spin_lock_bh(&buffer->lock);

        if (!buffer->valid) {
                if (reorder & IWL_RX_MPDU_REORDER_BA_OLD_SN) {
                        spin_unlock_bh(&buffer->lock);
                        return false;
                }
                buffer->valid = true;
        }

        if (ieee80211_is_back_req(hdr->frame_control)) {
                iwl_mvm_release_frames(mvm, sta, napi, buffer, nssn);
                goto drop;
        }

        /*
         * If there was a significant jump in the nssn - adjust.
         * If the SN is smaller than the NSSN it might need to first go into
         * the reorder buffer, in which case we just release up to it and the
         * rest of the function will take care of storing it and releasing up to
         * the nssn
         */
        if (!iwl_mvm_is_sn_less(nssn, buffer->head_sn + buffer->buf_size,
                                buffer->buf_size) ||
            !ieee80211_sn_less(sn, buffer->head_sn + buffer->buf_size)) {
                u16 min_sn = ieee80211_sn_less(sn, nssn) ? sn : nssn;

                iwl_mvm_release_frames(mvm, sta, napi, buffer, min_sn);
        }

        /* drop any oudated packets */
        if (ieee80211_sn_less(sn, buffer->head_sn))
                goto drop;

        /* release immediately if allowed by nssn and no stored frames */
        if (!buffer->num_stored && ieee80211_sn_less(sn, nssn)) {
                if (iwl_mvm_is_sn_less(buffer->head_sn, nssn,
                                       buffer->buf_size) &&
                   (!amsdu || last_subframe))
                        buffer->head_sn = nssn;
                /* No need to update AMSDU last SN - we are moving the head */
                spin_unlock_bh(&buffer->lock);
                return false;
        }

        index = sn % buffer->buf_size;

        /*
         * Check if we already stored this frame
         * As AMSDU is either received or not as whole, logic is simple:
         * If we have frames in that position in the buffer and the last frame
         * originated from AMSDU had a different SN then it is a retransmission.
         * If it is the same SN then if the subframe index is incrementing it
         * is the same AMSDU - otherwise it is a retransmission.
         */
        tail = skb_peek_tail(&buffer->entries[index]);
        if (tail && !amsdu)
                goto drop;
        else if (tail && (sn != buffer->last_amsdu ||
                          buffer->last_sub_index >= sub_frame_idx))
                goto drop;

        /* put in reorder buffer */
        __skb_queue_tail(&buffer->entries[index], skb);
        buffer->num_stored++;
        buffer->reorder_time[index] = jiffies;

        if (amsdu) {
                buffer->last_amsdu = sn;
                buffer->last_sub_index = sub_frame_idx;
        }

        /*
         * We cannot trust NSSN for AMSDU sub-frames that are not the last.
         * The reason is that NSSN advances on the first sub-frame, and may
         * cause the reorder buffer to advance before all the sub-frames arrive.
         * Example: reorder buffer contains SN 0 & 2, and we receive AMSDU with
         * SN 1. NSSN for first sub frame will be 3 with the result of driver
         * releasing SN 0,1, 2. When sub-frame 1 arrives - reorder buffer is
         * already ahead and it will be dropped.
         * If the last sub-frame is not on this queue - we will get frame
         * release notification with up to date NSSN.
         */
        if (!amsdu || last_subframe)
                iwl_mvm_release_frames(mvm, sta, napi, buffer, nssn);

        spin_unlock_bh(&buffer->lock);
        return true;

drop:
        kfree_skb(skb);
        spin_unlock_bh(&buffer->lock);
        return true;
}

static void iwl_mvm_agg_rx_received(struct iwl_mvm *mvm,
                                    u32 reorder_data, u8 baid)
{
        unsigned long now = jiffies;
        unsigned long timeout;
        struct iwl_mvm_baid_data *data;

        rcu_read_lock();

        data = rcu_dereference(mvm->baid_map[baid]);
        if (!data) {
                IWL_DEBUG_RX(mvm,
                             "Got valid BAID but no baid allocated, bypass the re-ordering buffer. Baid %d reorder 0x%x\n",
                              baid, reorder_data);
                goto out;
        }

        if (!data->timeout)
                goto out;

        timeout = data->timeout;
        /*
         * Do not update last rx all the time to avoid cache bouncing
         * between the rx queues.
         * Update it every timeout. Worst case is the session will
         * expire after ~ 2 * timeout, which doesn't matter that much.
         */
        if (time_before(data->last_rx + TU_TO_JIFFIES(timeout), now))
                /* Update is atomic */
                data->last_rx = now;

out:
        rcu_read_unlock();
}

void iwl_mvm_rx_mpdu_mq(struct iwl_mvm *mvm, struct napi_struct *napi,
                        struct iwl_rx_cmd_buffer *rxb, int queue)
{
        struct ieee80211_rx_status *rx_status;
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_rx_mpdu_desc *desc = (void *)pkt->data;
        struct ieee80211_hdr *hdr = (void *)(pkt->data + sizeof(*desc));
        u32 len = le16_to_cpu(desc->mpdu_len);
        u32 rate_n_flags = le32_to_cpu(desc->rate_n_flags);
        u16 phy_info = le16_to_cpu(desc->phy_info);
        struct ieee80211_sta *sta = NULL;
        struct sk_buff *skb;
        u8 crypt_len = 0;

        /* Dont use dev_alloc_skb(), we'll have enough headroom once
         * ieee80211_hdr pulled.
         */
        skb = alloc_skb(128, GFP_ATOMIC);
        if (!skb) {
                IWL_ERR(mvm, "alloc_skb failed\n");
                return;
        }

        rx_status = IEEE80211_SKB_RXCB(skb);

        if (iwl_mvm_rx_crypto(mvm, hdr, rx_status, desc, queue, &crypt_len)) {
                kfree_skb(skb);
                return;
        }

        /*
         * Keep packets with CRC errors (and with overrun) for monitor mode
         * (otherwise the firmware discards them) but mark them as bad.
         */
        if (!(desc->status & cpu_to_le16(IWL_RX_MPDU_STATUS_CRC_OK)) ||
            !(desc->status & cpu_to_le16(IWL_RX_MPDU_STATUS_OVERRUN_OK))) {
                IWL_DEBUG_RX(mvm, "Bad CRC or FIFO: 0x%08X.\n",
                             le16_to_cpu(desc->status));
                rx_status->flag |= RX_FLAG_FAILED_FCS_CRC;
        }
        /* set the preamble flag if appropriate */
        if (phy_info & IWL_RX_MPDU_PHY_SHORT_PREAMBLE)
                rx_status->enc_flags |= RX_ENC_FLAG_SHORTPRE;

        if (likely(!(phy_info & IWL_RX_MPDU_PHY_TSF_OVERLOAD))) {
                rx_status->mactime = le64_to_cpu(desc->tsf_on_air_rise);
                /* TSF as indicated by the firmware is at INA time */
                rx_status->flag |= RX_FLAG_MACTIME_PLCP_START;
        }
        rx_status->device_timestamp = le32_to_cpu(desc->gp2_on_air_rise);
        rx_status->band = desc->channel > 14 ? NL80211_BAND_5GHZ :
                                               NL80211_BAND_2GHZ;
        rx_status->freq = ieee80211_channel_to_frequency(desc->channel,
                                                         rx_status->band);
        iwl_mvm_get_signal_strength(mvm, desc, rx_status);

        /* update aggregation data for monitor sake on default queue */
        if (!queue && (phy_info & IWL_RX_MPDU_PHY_AMPDU)) {
                bool toggle_bit = phy_info & IWL_RX_MPDU_PHY_AMPDU_TOGGLE;

                rx_status->flag |= RX_FLAG_AMPDU_DETAILS;
                rx_status->ampdu_reference = mvm->ampdu_ref;
                /* toggle is switched whenever new aggregation starts */
                if (toggle_bit != mvm->ampdu_toggle) {
                        mvm->ampdu_ref++;
                        mvm->ampdu_toggle = toggle_bit;
                }
        }

        rcu_read_lock();

        if (desc->status & cpu_to_le16(IWL_RX_MPDU_STATUS_SRC_STA_FOUND)) {
                u8 id = desc->sta_id_flags & IWL_RX_MPDU_SIF_STA_ID_MASK;

                if (!WARN_ON_ONCE(id >= ARRAY_SIZE(mvm->fw_id_to_mac_id))) {
                        sta = rcu_dereference(mvm->fw_id_to_mac_id[id]);
                        if (IS_ERR(sta))
                                sta = NULL;
                }
        } else if (!is_multicast_ether_addr(hdr->addr2)) {
                /*
                 * This is fine since we prevent two stations with the same
                 * address from being added.
                 */
                sta = ieee80211_find_sta_by_ifaddr(mvm->hw, hdr->addr2, NULL);
        }

        if (sta) {
                struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
                struct ieee80211_vif *tx_blocked_vif =
                        rcu_dereference(mvm->csa_tx_blocked_vif);
                u8 baid = (u8)((le32_to_cpu(desc->reorder_data) &
                               IWL_RX_MPDU_REORDER_BAID_MASK) >>
                               IWL_RX_MPDU_REORDER_BAID_SHIFT);

                /*
                 * We have tx blocked stations (with CS bit). If we heard
                 * frames from a blocked station on a new channel we can
                 * TX to it again.
                 */
                if (unlikely(tx_blocked_vif) &&
                    tx_blocked_vif == mvmsta->vif) {
                        struct iwl_mvm_vif *mvmvif =
                                iwl_mvm_vif_from_mac80211(tx_blocked_vif);

                        if (mvmvif->csa_target_freq == rx_status->freq)
                                iwl_mvm_sta_modify_disable_tx_ap(mvm, sta,
                                                                 false);
                }

                rs_update_last_rssi(mvm, &mvmsta->lq_sta, rx_status);

                if (iwl_fw_dbg_trigger_enabled(mvm->fw, FW_DBG_TRIGGER_RSSI) &&
                    ieee80211_is_beacon(hdr->frame_control)) {
                        struct iwl_fw_dbg_trigger_tlv *trig;
                        struct iwl_fw_dbg_trigger_low_rssi *rssi_trig;
                        bool trig_check;
                        s32 rssi;

                        trig = iwl_fw_dbg_get_trigger(mvm->fw,
                                                      FW_DBG_TRIGGER_RSSI);
                        rssi_trig = (void *)trig->data;
                        rssi = le32_to_cpu(rssi_trig->rssi);

                        trig_check =
                                iwl_fw_dbg_trigger_check_stop(&mvm->fwrt,
                                                              ieee80211_vif_to_wdev(mvmsta->vif),
                                                              trig);
                        if (trig_check && rx_status->signal < rssi)
                                iwl_fw_dbg_collect_trig(&mvm->fwrt, trig,
                                                        NULL);
                }

                if (ieee80211_is_data(hdr->frame_control))
                        iwl_mvm_rx_csum(sta, skb, desc);

                if (iwl_mvm_is_nonagg_dup(sta, queue, rx_status, hdr, desc)) {
                        kfree_skb(skb);
                        goto out;
                }

                /*
                 * Our hardware de-aggregates AMSDUs but copies the mac header
                 * as it to the de-aggregated MPDUs. We need to turn off the
                 * AMSDU bit in the QoS control ourselves.
                 * In addition, HW reverses addr3 and addr4 - reverse it back.
                 */
                if ((desc->mac_flags2 & IWL_RX_MPDU_MFLG2_AMSDU) &&
                    !WARN_ON(!ieee80211_is_data_qos(hdr->frame_control))) {
                        int i;
                        u8 *qc = ieee80211_get_qos_ctl(hdr);
                        u8 mac_addr[ETH_ALEN];

                        *qc &= ~IEEE80211_QOS_CTL_A_MSDU_PRESENT;

                        for (i = 0; i < ETH_ALEN; i++)
                                mac_addr[i] = hdr->addr3[ETH_ALEN - i - 1];
                        ether_addr_copy(hdr->addr3, mac_addr);

                        if (ieee80211_has_a4(hdr->frame_control)) {
                                for (i = 0; i < ETH_ALEN; i++)
                                        mac_addr[i] =
                                                hdr->addr4[ETH_ALEN - i - 1];
                                ether_addr_copy(hdr->addr4, mac_addr);
                        }
                }
                if (baid != IWL_RX_REORDER_DATA_INVALID_BAID) {
                        u32 reorder_data = le32_to_cpu(desc->reorder_data);

                        iwl_mvm_agg_rx_received(mvm, reorder_data, baid);
                }
        }

        /* Set up the HT phy flags */
        switch (rate_n_flags & RATE_MCS_CHAN_WIDTH_MSK) {
        case RATE_MCS_CHAN_WIDTH_20:
                break;
        case RATE_MCS_CHAN_WIDTH_40:
                rx_status->bw = RATE_INFO_BW_40;
                break;
        case RATE_MCS_CHAN_WIDTH_80:
                rx_status->bw = RATE_INFO_BW_80;
                break;
        case RATE_MCS_CHAN_WIDTH_160:
                rx_status->bw = RATE_INFO_BW_160;
                break;
        }
        if (rate_n_flags & RATE_MCS_SGI_MSK)
                rx_status->enc_flags |= RX_ENC_FLAG_SHORT_GI;
        if (rate_n_flags & RATE_HT_MCS_GF_MSK)
                rx_status->enc_flags |= RX_ENC_FLAG_HT_GF;
        if (rate_n_flags & RATE_MCS_LDPC_MSK)
                rx_status->enc_flags |= RX_ENC_FLAG_LDPC;
        if (rate_n_flags & RATE_MCS_HT_MSK) {
                u8 stbc = (rate_n_flags & RATE_MCS_STBC_MSK) >>
                                RATE_MCS_STBC_POS;
                rx_status->encoding = RX_ENC_HT;
                rx_status->rate_idx = rate_n_flags & RATE_HT_MCS_INDEX_MSK;
                rx_status->enc_flags |= stbc << RX_ENC_FLAG_STBC_SHIFT;
        } else if (rate_n_flags & RATE_MCS_VHT_MSK) {
                u8 stbc = (rate_n_flags & RATE_MCS_STBC_MSK) >>
                                RATE_MCS_STBC_POS;
                rx_status->nss =
                        ((rate_n_flags & RATE_VHT_MCS_NSS_MSK) >>
                                                RATE_VHT_MCS_NSS_POS) + 1;
                rx_status->rate_idx = rate_n_flags & RATE_VHT_MCS_RATE_CODE_MSK;
                rx_status->encoding = RX_ENC_VHT;
                rx_status->enc_flags |= stbc << RX_ENC_FLAG_STBC_SHIFT;
                if (rate_n_flags & RATE_MCS_BF_MSK)
                        rx_status->enc_flags |= RX_ENC_FLAG_BF;
        } else {
                int rate = iwl_mvm_legacy_rate_to_mac80211_idx(rate_n_flags,
                                                               rx_status->band);

                if (WARN(rate < 0 || rate > 0xFF,
                         "Invalid rate flags 0x%x, band %d,\n",
                         rate_n_flags, rx_status->band)) {
                        kfree_skb(skb);
                        goto out;
                }
                rx_status->rate_idx = rate;

        }

        /* management stuff on default queue */
        if (!queue) {
                if (unlikely((ieee80211_is_beacon(hdr->frame_control) ||
                              ieee80211_is_probe_resp(hdr->frame_control)) &&
                             mvm->sched_scan_pass_all ==
                             SCHED_SCAN_PASS_ALL_ENABLED))
                        mvm->sched_scan_pass_all = SCHED_SCAN_PASS_ALL_FOUND;

                if (unlikely(ieee80211_is_beacon(hdr->frame_control) ||
                             ieee80211_is_probe_resp(hdr->frame_control)))
                        rx_status->boottime_ns = ktime_get_boot_ns();
        }

        iwl_mvm_create_skb(skb, hdr, len, crypt_len, rxb);
        if (!iwl_mvm_reorder(mvm, napi, queue, sta, skb, desc))
                iwl_mvm_pass_packet_to_mac80211(mvm, napi, skb, queue, sta);
out:
        rcu_read_unlock();
}

void iwl_mvm_rx_frame_release(struct iwl_mvm *mvm, struct napi_struct *napi,
                              struct iwl_rx_cmd_buffer *rxb, int queue)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_frame_release *release = (void *)pkt->data;
        struct ieee80211_sta *sta;
        struct iwl_mvm_reorder_buffer *reorder_buf;
        struct iwl_mvm_baid_data *ba_data;

        int baid = release->baid;

        IWL_DEBUG_HT(mvm, "Frame release notification for BAID %u, NSSN %d\n",
                     release->baid, le16_to_cpu(release->nssn));

        if (WARN_ON_ONCE(baid == IWL_RX_REORDER_DATA_INVALID_BAID))
                return;

        rcu_read_lock();

        ba_data = rcu_dereference(mvm->baid_map[baid]);
        if (WARN_ON_ONCE(!ba_data))
                goto out;

        sta = rcu_dereference(mvm->fw_id_to_mac_id[ba_data->sta_id]);
        if (WARN_ON_ONCE(IS_ERR_OR_NULL(sta)))
                goto out;

        reorder_buf = &ba_data->reorder_buf[queue];

        spin_lock_bh(&reorder_buf->lock);
        iwl_mvm_release_frames(mvm, sta, napi, reorder_buf,
                               le16_to_cpu(release->nssn));
        spin_unlock_bh(&reorder_buf->lock);

out:
        rcu_read_unlock();
}