/******************************************************************************
 *
 * Copyright(c) 2003 - 2014 Intel Corporation. All rights reserved.
 * Copyright(c) 2015 Intel Deutschland GmbH
 *
 * Portions of this file are derived from the ipw3945 project, as well
 * as portionhelp of the ieee80211 subsystem header files.
 *
 * 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.
 *
 * Contact Information:
 *  Intel Linux Wireless <linuxwifi@intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include <linux/etherdevice.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>

#include "iwl-trans.h"
#include "iwl-io.h"
#include "dev.h"
#include "calib.h"
#include "agn.h"

/******************************************************************************
 *
 * Generic RX handler implementations
 *
 ******************************************************************************/

static void iwlagn_rx_reply_error(struct iwl_priv *priv,
                                  struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_error_resp *err_resp = (void *)pkt->data;

        IWL_ERR(priv, "Error Reply type 0x%08X cmd REPLY_ERROR (0x%02X) "
                "seq 0x%04X ser 0x%08X\n",
                le32_to_cpu(err_resp->error_type),
                err_resp->cmd_id,
                le16_to_cpu(err_resp->bad_cmd_seq_num),
                le32_to_cpu(err_resp->error_info));
}

static void iwlagn_rx_csa(struct iwl_priv *priv, struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_csa_notification *csa = (void *)pkt->data;
        /*
         * MULTI-FIXME
         * See iwlagn_mac_channel_switch.
         */
        struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
        struct iwl_rxon_cmd *rxon = (void *)&ctx->active;

        if (!test_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status))
                return;

        if (!le32_to_cpu(csa->status) && csa->channel == priv->switch_channel) {
                rxon->channel = csa->channel;
                ctx->staging.channel = csa->channel;
                IWL_DEBUG_11H(priv, "CSA notif: channel %d\n",
                              le16_to_cpu(csa->channel));
                iwl_chswitch_done(priv, true);
        } else {
                IWL_ERR(priv, "CSA notif (fail) : channel %d\n",
                        le16_to_cpu(csa->channel));
                iwl_chswitch_done(priv, false);
        }
}


static void iwlagn_rx_spectrum_measure_notif(struct iwl_priv *priv,
                                             struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_spectrum_notification *report = (void *)pkt->data;

        if (!report->state) {
                IWL_DEBUG_11H(priv,
                        "Spectrum Measure Notification: Start\n");
                return;
        }

        memcpy(&priv->measure_report, report, sizeof(*report));
        priv->measurement_status |= MEASUREMENT_READY;
}

static void iwlagn_rx_pm_sleep_notif(struct iwl_priv *priv,
                                     struct iwl_rx_cmd_buffer *rxb)
{
#ifdef CONFIG_IWLWIFI_DEBUG
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_sleep_notification *sleep = (void *)pkt->data;
        IWL_DEBUG_RX(priv, "sleep mode: %d, src: %d\n",
                     sleep->pm_sleep_mode, sleep->pm_wakeup_src);
#endif
}

static void iwlagn_rx_pm_debug_statistics_notif(struct iwl_priv *priv,
                                                struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        u32 __maybe_unused len = iwl_rx_packet_len(pkt);
        IWL_DEBUG_RADIO(priv, "Dumping %d bytes of unhandled "
                        "notification for PM_DEBUG_STATISTIC_NOTIFIC:\n", len);
        iwl_print_hex_dump(priv, IWL_DL_RADIO, pkt->data, len);
}

static void iwlagn_rx_beacon_notif(struct iwl_priv *priv,
                                   struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwlagn_beacon_notif *beacon = (void *)pkt->data;
#ifdef CONFIG_IWLWIFI_DEBUG
        u16 status = le16_to_cpu(beacon->beacon_notify_hdr.status.status);
        u8 rate = iwl_hw_get_rate(beacon->beacon_notify_hdr.rate_n_flags);

        IWL_DEBUG_RX(priv, "beacon status %#x, retries:%d ibssmgr:%d "
                "tsf:0x%.8x%.8x rate:%d\n",
                status & TX_STATUS_MSK,
                beacon->beacon_notify_hdr.failure_frame,
                le32_to_cpu(beacon->ibss_mgr_status),
                le32_to_cpu(beacon->high_tsf),
                le32_to_cpu(beacon->low_tsf), rate);
#endif

        priv->ibss_manager = le32_to_cpu(beacon->ibss_mgr_status);
}

/**
 * iwl_good_plcp_health - checks for plcp error.
 *
 * When the plcp error is exceeding the thresholds, reset the radio
 * to improve the throughput.
 */
static bool iwlagn_good_plcp_health(struct iwl_priv *priv,
                                 struct statistics_rx_phy *cur_ofdm,
                                 struct statistics_rx_ht_phy *cur_ofdm_ht,
                                 unsigned int msecs)
{
        int delta;
        int threshold = priv->plcp_delta_threshold;

        if (threshold == IWL_MAX_PLCP_ERR_THRESHOLD_DISABLE) {
                IWL_DEBUG_RADIO(priv, "plcp_err check disabled\n");
                return true;
        }

        delta = le32_to_cpu(cur_ofdm->plcp_err) -
                le32_to_cpu(priv->statistics.rx_ofdm.plcp_err) +
                le32_to_cpu(cur_ofdm_ht->plcp_err) -
                le32_to_cpu(priv->statistics.rx_ofdm_ht.plcp_err);

        /* Can be negative if firmware reset statistics */
        if (delta <= 0)
                return true;

        if ((delta * 100 / msecs) > threshold) {
                IWL_DEBUG_RADIO(priv,
                                "plcp health threshold %u delta %d msecs %u\n",
                                threshold, delta, msecs);
                return false;
        }

        return true;
}

int iwl_force_rf_reset(struct iwl_priv *priv, bool external)
{
        struct iwl_rf_reset *rf_reset;

        if (test_bit(STATUS_EXIT_PENDING, &priv->status))
                return -EAGAIN;

        if (!iwl_is_any_associated(priv)) {
                IWL_DEBUG_SCAN(priv, "force reset rejected: not associated\n");
                return -ENOLINK;
        }

        rf_reset = &priv->rf_reset;
        rf_reset->reset_request_count++;
        if (!external && rf_reset->last_reset_jiffies &&
            time_after(rf_reset->last_reset_jiffies +
                       IWL_DELAY_NEXT_FORCE_RF_RESET, jiffies)) {
                IWL_DEBUG_INFO(priv, "RF reset rejected\n");
                rf_reset->reset_reject_count++;
                return -EAGAIN;
        }
        rf_reset->reset_success_count++;
        rf_reset->last_reset_jiffies = jiffies;

        /*
         * There is no easy and better way to force reset the radio,
         * the only known method is switching channel which will force to
         * reset and tune the radio.
         * Use internal short scan (single channel) operation to should
         * achieve this objective.
         * Driver should reset the radio when number of consecutive missed
         * beacon, or any other uCode error condition detected.
         */
        IWL_DEBUG_INFO(priv, "perform radio reset.\n");
        iwl_internal_short_hw_scan(priv);
        return 0;
}


static void iwlagn_recover_from_statistics(struct iwl_priv *priv,
                                struct statistics_rx_phy *cur_ofdm,
                                struct statistics_rx_ht_phy *cur_ofdm_ht,
                                struct statistics_tx *tx,
                                unsigned long stamp)
{
        unsigned int msecs;

        if (test_bit(STATUS_EXIT_PENDING, &priv->status))
                return;

        msecs = jiffies_to_msecs(stamp - priv->rx_statistics_jiffies);

        /* Only gather statistics and update time stamp when not associated */
        if (!iwl_is_any_associated(priv))
                return;

        /* Do not check/recover when do not have enough statistics data */
        if (msecs < 99)
                return;

        if (!iwlagn_good_plcp_health(priv, cur_ofdm, cur_ofdm_ht, msecs))
                iwl_force_rf_reset(priv, false);
}

/* Calculate noise level, based on measurements during network silence just
 *   before arriving beacon.  This measurement can be done only if we know
 *   exactly when to expect beacons, therefore only when we're associated. */
static void iwlagn_rx_calc_noise(struct iwl_priv *priv)
{
        struct statistics_rx_non_phy *rx_info;
        int num_active_rx = 0;
        int total_silence = 0;
        int bcn_silence_a, bcn_silence_b, bcn_silence_c;
        int last_rx_noise;

        rx_info = &priv->statistics.rx_non_phy;

        bcn_silence_a =
                le32_to_cpu(rx_info->beacon_silence_rssi_a) & IN_BAND_FILTER;
        bcn_silence_b =
                le32_to_cpu(rx_info->beacon_silence_rssi_b) & IN_BAND_FILTER;
        bcn_silence_c =
                le32_to_cpu(rx_info->beacon_silence_rssi_c) & IN_BAND_FILTER;

        if (bcn_silence_a) {
                total_silence += bcn_silence_a;
                num_active_rx++;
        }
        if (bcn_silence_b) {
                total_silence += bcn_silence_b;
                num_active_rx++;
        }
        if (bcn_silence_c) {
                total_silence += bcn_silence_c;
                num_active_rx++;
        }

        /* Average among active antennas */
        if (num_active_rx)
                last_rx_noise = (total_silence / num_active_rx) - 107;
        else
                last_rx_noise = IWL_NOISE_MEAS_NOT_AVAILABLE;

        IWL_DEBUG_CALIB(priv, "inband silence a %u, b %u, c %u, dBm %d\n",
                        bcn_silence_a, bcn_silence_b, bcn_silence_c,
                        last_rx_noise);
}

#ifdef CONFIG_IWLWIFI_DEBUGFS
/*
 *  based on the assumption of all statistics counter are in DWORD
 *  FIXME: This function is for debugging, do not deal with
 *  the case of counters roll-over.
 */
static void accum_stats(__le32 *prev, __le32 *cur, __le32 *delta,
                        __le32 *max_delta, __le32 *accum, int size)
{
        int i;

        for (i = 0;
             i < size / sizeof(__le32);
             i++, prev++, cur++, delta++, max_delta++, accum++) {
                if (le32_to_cpu(*cur) > le32_to_cpu(*prev)) {
                        *delta = cpu_to_le32(
                                le32_to_cpu(*cur) - le32_to_cpu(*prev));
                        le32_add_cpu(accum, le32_to_cpu(*delta));
                        if (le32_to_cpu(*delta) > le32_to_cpu(*max_delta))
                                *max_delta = *delta;
                }
        }
}

static void
iwlagn_accumulative_statistics(struct iwl_priv *priv,
                            struct statistics_general_common *common,
                            struct statistics_rx_non_phy *rx_non_phy,
                            struct statistics_rx_phy *rx_ofdm,
                            struct statistics_rx_ht_phy *rx_ofdm_ht,
                            struct statistics_rx_phy *rx_cck,
                            struct statistics_tx *tx,
                            struct statistics_bt_activity *bt_activity)
{
#define ACCUM(_name)    \
        accum_stats((__le32 *)&priv->statistics._name,          \
                    (__le32 *)_name,                            \
                    (__le32 *)&priv->delta_stats._name,         \
                    (__le32 *)&priv->max_delta_stats._name,     \
                    (__le32 *)&priv->accum_stats._name,         \
                    sizeof(*_name));

        ACCUM(common);
        ACCUM(rx_non_phy);
        ACCUM(rx_ofdm);
        ACCUM(rx_ofdm_ht);
        ACCUM(rx_cck);
        ACCUM(tx);
        if (bt_activity)
                ACCUM(bt_activity);
#undef ACCUM
}
#else
static inline void
iwlagn_accumulative_statistics(struct iwl_priv *priv,
                            struct statistics_general_common *common,
                            struct statistics_rx_non_phy *rx_non_phy,
                            struct statistics_rx_phy *rx_ofdm,
                            struct statistics_rx_ht_phy *rx_ofdm_ht,
                            struct statistics_rx_phy *rx_cck,
                            struct statistics_tx *tx,
                            struct statistics_bt_activity *bt_activity)
{
}
#endif

static void iwlagn_rx_statistics(struct iwl_priv *priv,
                                 struct iwl_rx_cmd_buffer *rxb)
{
        unsigned long stamp = jiffies;
        const int reg_recalib_period = 60;
        int change;
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        u32 len = iwl_rx_packet_payload_len(pkt);
        __le32 *flag;
        struct statistics_general_common *common;
        struct statistics_rx_non_phy *rx_non_phy;
        struct statistics_rx_phy *rx_ofdm;
        struct statistics_rx_ht_phy *rx_ofdm_ht;
        struct statistics_rx_phy *rx_cck;
        struct statistics_tx *tx;
        struct statistics_bt_activity *bt_activity;

        IWL_DEBUG_RX(priv, "Statistics notification received (%d bytes).\n",
                     len);

        spin_lock(&priv->statistics.lock);

        if (len == sizeof(struct iwl_bt_notif_statistics)) {
                struct iwl_bt_notif_statistics *stats;
                stats = (void *)&pkt->data;
                flag = &stats->flag;
                common = &stats->general.common;
                rx_non_phy = &stats->rx.general.common;
                rx_ofdm = &stats->rx.ofdm;
                rx_ofdm_ht = &stats->rx.ofdm_ht;
                rx_cck = &stats->rx.cck;
                tx = &stats->tx;
                bt_activity = &stats->general.activity;

#ifdef CONFIG_IWLWIFI_DEBUGFS
                /* handle this exception directly */
                priv->statistics.num_bt_kills = stats->rx.general.num_bt_kills;
                le32_add_cpu(&priv->statistics.accum_num_bt_kills,
                             le32_to_cpu(stats->rx.general.num_bt_kills));
#endif
        } else if (len == sizeof(struct iwl_notif_statistics)) {
                struct iwl_notif_statistics *stats;
                stats = (void *)&pkt->data;
                flag = &stats->flag;
                common = &stats->general.common;
                rx_non_phy = &stats->rx.general;
                rx_ofdm = &stats->rx.ofdm;
                rx_ofdm_ht = &stats->rx.ofdm_ht;
                rx_cck = &stats->rx.cck;
                tx = &stats->tx;
                bt_activity = NULL;
        } else {
                WARN_ONCE(1, "len %d doesn't match BT (%zu) or normal (%zu)\n",
                          len, sizeof(struct iwl_bt_notif_statistics),
                          sizeof(struct iwl_notif_statistics));
                spin_unlock(&priv->statistics.lock);
                return;
        }

        change = common->temperature != priv->statistics.common.temperature ||
                 (*flag & STATISTICS_REPLY_FLG_HT40_MODE_MSK) !=
                 (priv->statistics.flag & STATISTICS_REPLY_FLG_HT40_MODE_MSK);

        iwlagn_accumulative_statistics(priv, common, rx_non_phy, rx_ofdm,
                                    rx_ofdm_ht, rx_cck, tx, bt_activity);

        iwlagn_recover_from_statistics(priv, rx_ofdm, rx_ofdm_ht, tx, stamp);

        priv->statistics.flag = *flag;
        memcpy(&priv->statistics.common, common, sizeof(*common));
        memcpy(&priv->statistics.rx_non_phy, rx_non_phy, sizeof(*rx_non_phy));
        memcpy(&priv->statistics.rx_ofdm, rx_ofdm, sizeof(*rx_ofdm));
        memcpy(&priv->statistics.rx_ofdm_ht, rx_ofdm_ht, sizeof(*rx_ofdm_ht));
        memcpy(&priv->statistics.rx_cck, rx_cck, sizeof(*rx_cck));
        memcpy(&priv->statistics.tx, tx, sizeof(*tx));
#ifdef CONFIG_IWLWIFI_DEBUGFS
        if (bt_activity)
                memcpy(&priv->statistics.bt_activity, bt_activity,
                        sizeof(*bt_activity));
#endif

        priv->rx_statistics_jiffies = stamp;

        set_bit(STATUS_STATISTICS, &priv->status);

        /* Reschedule the statistics timer to occur in
         * reg_recalib_period seconds to ensure we get a
         * thermal update even if the uCode doesn't give
         * us one */
        mod_timer(&priv->statistics_periodic, jiffies +
                  msecs_to_jiffies(reg_recalib_period * 1000));

        if (unlikely(!test_bit(STATUS_SCANNING, &priv->status)) &&
            (pkt->hdr.cmd == STATISTICS_NOTIFICATION)) {
                iwlagn_rx_calc_noise(priv);
                queue_work(priv->workqueue, &priv->run_time_calib_work);
        }
        if (priv->lib->temperature && change)
                priv->lib->temperature(priv);

        spin_unlock(&priv->statistics.lock);
}

static void iwlagn_rx_reply_statistics(struct iwl_priv *priv,
                                       struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_notif_statistics *stats = (void *)pkt->data;

        if (le32_to_cpu(stats->flag) & UCODE_STATISTICS_CLEAR_MSK) {
#ifdef CONFIG_IWLWIFI_DEBUGFS
                memset(&priv->accum_stats, 0,
                        sizeof(priv->accum_stats));
                memset(&priv->delta_stats, 0,
                        sizeof(priv->delta_stats));
                memset(&priv->max_delta_stats, 0,
                        sizeof(priv->max_delta_stats));
#endif
                IWL_DEBUG_RX(priv, "Statistics have been cleared\n");
        }

        iwlagn_rx_statistics(priv, rxb);
}

/* Handle notification from uCode that card's power state is changing
 * due to software, hardware, or critical temperature RFKILL */
static void iwlagn_rx_card_state_notif(struct iwl_priv *priv,
                                       struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_card_state_notif *card_state_notif = (void *)pkt->data;
        u32 flags = le32_to_cpu(card_state_notif->flags);
        unsigned long status = priv->status;

        IWL_DEBUG_RF_KILL(priv, "Card state received: HW:%s SW:%s CT:%s\n",
                          (flags & HW_CARD_DISABLED) ? "Kill" : "On",
                          (flags & SW_CARD_DISABLED) ? "Kill" : "On",
                          (flags & CT_CARD_DISABLED) ?
                          "Reached" : "Not reached");

        if (flags & (SW_CARD_DISABLED | HW_CARD_DISABLED |
                     CT_CARD_DISABLED)) {

                iwl_write32(priv->trans, CSR_UCODE_DRV_GP1_SET,
                            CSR_UCODE_DRV_GP1_BIT_CMD_BLOCKED);

                iwl_write_direct32(priv->trans, HBUS_TARG_MBX_C,
                                        HBUS_TARG_MBX_C_REG_BIT_CMD_BLOCKED);

                if (!(flags & RXON_CARD_DISABLED)) {
                        iwl_write32(priv->trans, CSR_UCODE_DRV_GP1_CLR,
                                    CSR_UCODE_DRV_GP1_BIT_CMD_BLOCKED);
                        iwl_write_direct32(priv->trans, HBUS_TARG_MBX_C,
                                        HBUS_TARG_MBX_C_REG_BIT_CMD_BLOCKED);
                }
                if (flags & CT_CARD_DISABLED)
                        iwl_tt_enter_ct_kill(priv);
        }
        if (!(flags & CT_CARD_DISABLED))
                iwl_tt_exit_ct_kill(priv);

        if (flags & HW_CARD_DISABLED)
                set_bit(STATUS_RF_KILL_HW, &priv->status);
        else
                clear_bit(STATUS_RF_KILL_HW, &priv->status);


        if (!(flags & RXON_CARD_DISABLED))
                iwl_scan_cancel(priv);

        if ((test_bit(STATUS_RF_KILL_HW, &status) !=
             test_bit(STATUS_RF_KILL_HW, &priv->status)))
                wiphy_rfkill_set_hw_state(priv->hw->wiphy,
                        test_bit(STATUS_RF_KILL_HW, &priv->status));
}

static void iwlagn_rx_missed_beacon_notif(struct iwl_priv *priv,
                                          struct iwl_rx_cmd_buffer *rxb)

{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_missed_beacon_notif *missed_beacon = (void *)pkt->data;

        if (le32_to_cpu(missed_beacon->consecutive_missed_beacons) >
            priv->missed_beacon_threshold) {
                IWL_DEBUG_CALIB(priv,
                    "missed bcn cnsq %d totl %d rcd %d expctd %d\n",
                    le32_to_cpu(missed_beacon->consecutive_missed_beacons),
                    le32_to_cpu(missed_beacon->total_missed_becons),
                    le32_to_cpu(missed_beacon->num_recvd_beacons),
                    le32_to_cpu(missed_beacon->num_expected_beacons));
                if (!test_bit(STATUS_SCANNING, &priv->status))
                        iwl_init_sensitivity(priv);
        }
}

/* Cache phy data (Rx signal strength, etc) for HT frame (REPLY_RX_PHY_CMD).
 * This will be used later in iwl_rx_reply_rx() for REPLY_RX_MPDU_CMD. */
static void iwlagn_rx_reply_rx_phy(struct iwl_priv *priv,
                                   struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);

        priv->last_phy_res_valid = true;
        priv->ampdu_ref++;
        memcpy(&priv->last_phy_res, pkt->data,
               sizeof(struct iwl_rx_phy_res));
}

/*
 * returns non-zero if packet should be dropped
 */
static int iwlagn_set_decrypted_flag(struct iwl_priv *priv,
                                  struct ieee80211_hdr *hdr,
                                  u32 decrypt_res,
                                  struct ieee80211_rx_status *stats)
{
        u16 fc = le16_to_cpu(hdr->frame_control);

        /*
         * All contexts have the same setting here due to it being
         * a module parameter, so OK to check any context.
         */
        if (priv->contexts[IWL_RXON_CTX_BSS].active.filter_flags &
                                                RXON_FILTER_DIS_DECRYPT_MSK)
                return 0;

        if (!(fc & IEEE80211_FCTL_PROTECTED))
                return 0;

        IWL_DEBUG_RX(priv, "decrypt_res:0x%x\n", decrypt_res);
        switch (decrypt_res & RX_RES_STATUS_SEC_TYPE_MSK) {
        case RX_RES_STATUS_SEC_TYPE_TKIP:
                /* The uCode has got a bad phase 1 Key, pushes the packet.
                 * Decryption will be done in SW. */
                if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
                    RX_RES_STATUS_BAD_KEY_TTAK)
                        break;

        case RX_RES_STATUS_SEC_TYPE_WEP:
                if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
                    RX_RES_STATUS_BAD_ICV_MIC) {
                        /* bad ICV, the packet is destroyed since the
                         * decryption is inplace, drop it */
                        IWL_DEBUG_RX(priv, "Packet destroyed\n");
                        return -1;
                }
        case RX_RES_STATUS_SEC_TYPE_CCMP:
                if ((decrypt_res & RX_RES_STATUS_DECRYPT_TYPE_MSK) ==
                    RX_RES_STATUS_DECRYPT_OK) {
                        IWL_DEBUG_RX(priv, "hw decrypt successfully!!!\n");
                        stats->flag |= RX_FLAG_DECRYPTED;
                }
                break;

        default:
                break;
        }
        return 0;
}

static void iwlagn_pass_packet_to_mac80211(struct iwl_priv *priv,
                                        struct ieee80211_hdr *hdr,
                                        u16 len,
                                        u32 ampdu_status,
                                        struct iwl_rx_cmd_buffer *rxb,
                                        struct ieee80211_rx_status *stats)
{
        struct sk_buff *skb;
        __le16 fc = hdr->frame_control;
        struct iwl_rxon_context *ctx;
        unsigned int hdrlen, fraglen;

        /* We only process data packets if the interface is open */
        if (unlikely(!priv->is_open)) {
                IWL_DEBUG_DROP_LIMIT(priv,
                    "Dropping packet while interface is not open.\n");
                return;
        }

        /* In case of HW accelerated crypto and bad decryption, drop */
        if (!iwlwifi_mod_params.sw_crypto &&
            iwlagn_set_decrypted_flag(priv, hdr, ampdu_status, stats))
                return;

        /* Dont use dev_alloc_skb(), we'll have enough headroom once
         * ieee80211_hdr pulled.
         */
        skb = alloc_skb(128, GFP_ATOMIC);
        if (!skb) {
                IWL_ERR(priv, "alloc_skb failed\n");
                return;
        }
        /* If frame is small enough to fit in skb->head, pull it completely.
         * If not, only pull ieee80211_hdr so that splice() or TCP coalesce
         * are more efficient.
         */
        hdrlen = (len <= skb_tailroom(skb)) ? len : sizeof(*hdr);

        memcpy(skb_put(skb, hdrlen), hdr, hdrlen);
        fraglen = len - hdrlen;

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

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

        /*
        * Wake any queues that were stopped due to a passive channel tx
        * failure. This can happen because the regulatory enforcement in
        * the device waits for a beacon before allowing transmission,
        * sometimes even after already having transmitted frames for the
        * association because the new RXON may reset the information.
        */
        if (unlikely(ieee80211_is_beacon(fc) && priv->passive_no_rx)) {
                for_each_context(priv, ctx) {
                        if (!ether_addr_equal(hdr->addr3,
                                              ctx->active.bssid_addr))
                                continue;
                        iwlagn_lift_passive_no_rx(priv);
                }
        }

        memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));

        ieee80211_rx_napi(priv->hw, NULL, skb, priv->napi);
}

static u32 iwlagn_translate_rx_status(struct iwl_priv *priv, u32 decrypt_in)
{
        u32 decrypt_out = 0;

        if ((decrypt_in & RX_RES_STATUS_STATION_FOUND) ==
                                        RX_RES_STATUS_STATION_FOUND)
                decrypt_out |= (RX_RES_STATUS_STATION_FOUND |
                                RX_RES_STATUS_NO_STATION_INFO_MISMATCH);

        decrypt_out |= (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK);

        /* packet was not encrypted */
        if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
                                        RX_RES_STATUS_SEC_TYPE_NONE)
                return decrypt_out;

        /* packet was encrypted with unknown alg */
        if ((decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) ==
                                        RX_RES_STATUS_SEC_TYPE_ERR)
                return decrypt_out;

        /* decryption was not done in HW */
        if ((decrypt_in & RX_MPDU_RES_STATUS_DEC_DONE_MSK) !=
                                        RX_MPDU_RES_STATUS_DEC_DONE_MSK)
                return decrypt_out;

        switch (decrypt_in & RX_RES_STATUS_SEC_TYPE_MSK) {

        case RX_RES_STATUS_SEC_TYPE_CCMP:
                /* alg is CCM: check MIC only */
                if (!(decrypt_in & RX_MPDU_RES_STATUS_MIC_OK))
                        /* Bad MIC */
                        decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
                else
                        decrypt_out |= RX_RES_STATUS_DECRYPT_OK;

                break;

        case RX_RES_STATUS_SEC_TYPE_TKIP:
                if (!(decrypt_in & RX_MPDU_RES_STATUS_TTAK_OK)) {
                        /* Bad TTAK */
                        decrypt_out |= RX_RES_STATUS_BAD_KEY_TTAK;
                        break;
                }
                /* fall through if TTAK OK */
        default:
                if (!(decrypt_in & RX_MPDU_RES_STATUS_ICV_OK))
                        decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;
                else
                        decrypt_out |= RX_RES_STATUS_DECRYPT_OK;
                break;
        }

        IWL_DEBUG_RX(priv, "decrypt_in:0x%x  decrypt_out = 0x%x\n",
                                        decrypt_in, decrypt_out);

        return decrypt_out;
}

/* Calc max signal level (dBm) among 3 possible receivers */
static int iwlagn_calc_rssi(struct iwl_priv *priv,
                             struct iwl_rx_phy_res *rx_resp)
{
        /* data from PHY/DSP regarding signal strength, etc.,
         *   contents are always there, not configurable by host
         */
        struct iwlagn_non_cfg_phy *ncphy =
                (struct iwlagn_non_cfg_phy *)rx_resp->non_cfg_phy_buf;
        u32 val, rssi_a, rssi_b, rssi_c, max_rssi;
        u8 agc;

        val  = le32_to_cpu(ncphy->non_cfg_phy[IWLAGN_RX_RES_AGC_IDX]);
        agc = (val & IWLAGN_OFDM_AGC_MSK) >> IWLAGN_OFDM_AGC_BIT_POS;

        /* Find max rssi among 3 possible receivers.
         * These values are measured by the digital signal processor (DSP).
         * They should stay fairly constant even as the signal strength varies,
         *   if the radio's automatic gain control (AGC) is working right.
         * AGC value (see below) will provide the "interesting" info.
         */
        val = le32_to_cpu(ncphy->non_cfg_phy[IWLAGN_RX_RES_RSSI_AB_IDX]);
        rssi_a = (val & IWLAGN_OFDM_RSSI_INBAND_A_BITMSK) >>
                IWLAGN_OFDM_RSSI_A_BIT_POS;
        rssi_b = (val & IWLAGN_OFDM_RSSI_INBAND_B_BITMSK) >>
                IWLAGN_OFDM_RSSI_B_BIT_POS;
        val = le32_to_cpu(ncphy->non_cfg_phy[IWLAGN_RX_RES_RSSI_C_IDX]);
        rssi_c = (val & IWLAGN_OFDM_RSSI_INBAND_C_BITMSK) >>
                IWLAGN_OFDM_RSSI_C_BIT_POS;

        max_rssi = max_t(u32, rssi_a, rssi_b);
        max_rssi = max_t(u32, max_rssi, rssi_c);

        IWL_DEBUG_STATS(priv, "Rssi In A %d B %d C %d Max %d AGC dB %d\n",
                rssi_a, rssi_b, rssi_c, max_rssi, agc);

        /* dBm = max_rssi dB - agc dB - constant.
         * Higher AGC (higher radio gain) means lower signal. */
        return max_rssi - agc - IWLAGN_RSSI_OFFSET;
}

/* Called for REPLY_RX_MPDU_CMD */
static void iwlagn_rx_reply_rx(struct iwl_priv *priv,
                               struct iwl_rx_cmd_buffer *rxb)
{
        struct ieee80211_hdr *header;
        struct ieee80211_rx_status rx_status = {};
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_rx_phy_res *phy_res;
        __le32 rx_pkt_status;
        struct iwl_rx_mpdu_res_start *amsdu;
        u32 len;
        u32 ampdu_status;
        u32 rate_n_flags;

        if (!priv->last_phy_res_valid) {
                IWL_ERR(priv, "MPDU frame without cached PHY data\n");
                return;
        }
        phy_res = &priv->last_phy_res;
        amsdu = (struct iwl_rx_mpdu_res_start *)pkt->data;
        header = (struct ieee80211_hdr *)(pkt->data + sizeof(*amsdu));
        len = le16_to_cpu(amsdu->byte_count);
        rx_pkt_status = *(__le32 *)(pkt->data + sizeof(*amsdu) + len);
        ampdu_status = iwlagn_translate_rx_status(priv,
                                                  le32_to_cpu(rx_pkt_status));

        if ((unlikely(phy_res->cfg_phy_cnt > 20))) {
                IWL_DEBUG_DROP(priv, "dsp size out of range [0,20]: %d\n",
                                phy_res->cfg_phy_cnt);
                return;
        }

        if (!(rx_pkt_status & RX_RES_STATUS_NO_CRC32_ERROR) ||
            !(rx_pkt_status & RX_RES_STATUS_NO_RXE_OVERFLOW)) {
                IWL_DEBUG_RX(priv, "Bad CRC or FIFO: 0x%08X.\n",
                                le32_to_cpu(rx_pkt_status));
                return;
        }

        /* This will be used in several places later */
        rate_n_flags = le32_to_cpu(phy_res->rate_n_flags);

        /* rx_status carries information about the packet to mac80211 */
        rx_status.mactime = le64_to_cpu(phy_res->timestamp);
        rx_status.band = (phy_res->phy_flags & RX_RES_PHY_FLAGS_BAND_24_MSK) ?
                                NL80211_BAND_2GHZ : NL80211_BAND_5GHZ;
        rx_status.freq =
                ieee80211_channel_to_frequency(le16_to_cpu(phy_res->channel),
                                               rx_status.band);
        rx_status.rate_idx =
                iwlagn_hwrate_to_mac80211_idx(rate_n_flags, rx_status.band);
        rx_status.flag = 0;

        /* TSF isn't reliable. In order to allow smooth user experience,
         * this W/A doesn't propagate it to the mac80211 */
        /*rx_status.flag |= RX_FLAG_MACTIME_START;*/

        priv->ucode_beacon_time = le32_to_cpu(phy_res->beacon_time_stamp);

        /* Find max signal strength (dBm) among 3 antenna/receiver chains */
        rx_status.signal = iwlagn_calc_rssi(priv, phy_res);

        IWL_DEBUG_STATS_LIMIT(priv, "Rssi %d, TSF %llu\n",
                rx_status.signal, (unsigned long long)rx_status.mactime);

        /*
         * "antenna number"
         *
         * It seems that the antenna field in the phy flags value
         * is actually a bit field. This is undefined by radiotap,
         * it wants an actual antenna number but I always get "7"
         * for most legacy frames I receive indicating that the
         * same frame was received on all three RX chains.
         *
         * I think this field should be removed in favor of a
         * new 802.11n radiotap field "RX chains" that is defined
         * as a bitmask.
         */
        rx_status.antenna =
                (le16_to_cpu(phy_res->phy_flags) & RX_RES_PHY_FLAGS_ANTENNA_MSK)
                >> RX_RES_PHY_FLAGS_ANTENNA_POS;

        /* set the preamble flag if appropriate */
        if (phy_res->phy_flags & RX_RES_PHY_FLAGS_SHORT_PREAMBLE_MSK)
                rx_status.flag |= RX_FLAG_SHORTPRE;

        if (phy_res->phy_flags & RX_RES_PHY_FLAGS_AGG_MSK) {
                /*
                 * We know which subframes of an A-MPDU belong
                 * together since we get a single PHY response
                 * from the firmware for all of them
                 */
                rx_status.flag |= RX_FLAG_AMPDU_DETAILS;
                rx_status.ampdu_reference = priv->ampdu_ref;
        }

        /* Set up the HT phy flags */
        if (rate_n_flags & RATE_MCS_HT_MSK)
                rx_status.flag |= RX_FLAG_HT;
        if (rate_n_flags & RATE_MCS_HT40_MSK)
                rx_status.flag |= RX_FLAG_40MHZ;
        if (rate_n_flags & RATE_MCS_SGI_MSK)
                rx_status.flag |= RX_FLAG_SHORT_GI;
        if (rate_n_flags & RATE_MCS_GF_MSK)
                rx_status.flag |= RX_FLAG_HT_GF;

        iwlagn_pass_packet_to_mac80211(priv, header, len, ampdu_status,
                                    rxb, &rx_status);
}

static void iwlagn_rx_noa_notification(struct iwl_priv *priv,
                                       struct iwl_rx_cmd_buffer *rxb)
{
        struct iwl_wipan_noa_data *new_data, *old_data;
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_wipan_noa_notification *noa_notif = (void *)pkt->data;

        /* no condition -- we're in softirq */
        old_data = rcu_dereference_protected(priv->noa_data, true);

        if (noa_notif->noa_active) {
                u32 len = le16_to_cpu(noa_notif->noa_attribute.length);
                u32 copylen = len;

                /* EID, len, OUI, subtype */
                len += 1 + 1 + 3 + 1;
                /* P2P id, P2P length */
                len += 1 + 2;
                copylen += 1 + 2;

                new_data = kmalloc(sizeof(*new_data) + len, GFP_ATOMIC);
                if (new_data) {
                        new_data->length = len;
                        new_data->data[0] = WLAN_EID_VENDOR_SPECIFIC;
                        new_data->data[1] = len - 2; /* not counting EID, len */
                        new_data->data[2] = (WLAN_OUI_WFA >> 16) & 0xff;
                        new_data->data[3] = (WLAN_OUI_WFA >> 8) & 0xff;
                        new_data->data[4] = (WLAN_OUI_WFA >> 0) & 0xff;
                        new_data->data[5] = WLAN_OUI_TYPE_WFA_P2P;
                        memcpy(&new_data->data[6], &noa_notif->noa_attribute,
                               copylen);
                }
        } else
                new_data = NULL;

        rcu_assign_pointer(priv->noa_data, new_data);

        if (old_data)
                kfree_rcu(old_data, rcu_head);
}

/**
 * iwl_setup_rx_handlers - Initialize Rx handler callbacks
 *
 * Setup the RX handlers for each of the reply types sent from the uCode
 * to the host.
 */
void iwl_setup_rx_handlers(struct iwl_priv *priv)
{
        void (**handlers)(struct iwl_priv *priv, struct iwl_rx_cmd_buffer *rxb);

        handlers = priv->rx_handlers;

        handlers[REPLY_ERROR]                   = iwlagn_rx_reply_error;
        handlers[CHANNEL_SWITCH_NOTIFICATION]   = iwlagn_rx_csa;
        handlers[SPECTRUM_MEASURE_NOTIFICATION] =
                iwlagn_rx_spectrum_measure_notif;
        handlers[PM_SLEEP_NOTIFICATION]         = iwlagn_rx_pm_sleep_notif;
        handlers[PM_DEBUG_STATISTIC_NOTIFIC]    =
                iwlagn_rx_pm_debug_statistics_notif;
        handlers[BEACON_NOTIFICATION]           = iwlagn_rx_beacon_notif;
        handlers[REPLY_ADD_STA]                 = iwl_add_sta_callback;

        handlers[REPLY_WIPAN_NOA_NOTIFICATION]  = iwlagn_rx_noa_notification;

        /*
         * The same handler is used for both the REPLY to a discrete
         * statistics request from the host as well as for the periodic
         * statistics notifications (after received beacons) from the uCode.
         */
        handlers[REPLY_STATISTICS_CMD]          = iwlagn_rx_reply_statistics;
        handlers[STATISTICS_NOTIFICATION]       = iwlagn_rx_statistics;

        iwl_setup_rx_scan_handlers(priv);

        handlers[CARD_STATE_NOTIFICATION]       = iwlagn_rx_card_state_notif;
        handlers[MISSED_BEACONS_NOTIFICATION]   =
                iwlagn_rx_missed_beacon_notif;

        /* Rx handlers */
        handlers[REPLY_RX_PHY_CMD]              = iwlagn_rx_reply_rx_phy;
        handlers[REPLY_RX_MPDU_CMD]             = iwlagn_rx_reply_rx;

        /* block ack */
        handlers[REPLY_COMPRESSED_BA]           =
                iwlagn_rx_reply_compressed_ba;

        priv->rx_handlers[REPLY_TX] = iwlagn_rx_reply_tx;

        /* set up notification wait support */
        iwl_notification_wait_init(&priv->notif_wait);

        /* Set up BT Rx handlers */
        if (priv->lib->bt_params)
                iwlagn_bt_rx_handler_setup(priv);
}

void iwl_rx_dispatch(struct iwl_op_mode *op_mode, struct napi_struct *napi,
                     struct iwl_rx_cmd_buffer *rxb)

{
        struct iwl_rx_packet *pkt = rxb_addr(rxb);
        struct iwl_priv *priv = IWL_OP_MODE_GET_DVM(op_mode);

        /*
         * Do the notification wait before RX handlers so
         * even if the RX handler consumes the RXB we have
         * access to it in the notification wait entry.
         */
        iwl_notification_wait_notify(&priv->notif_wait, pkt);

        /* Based on type of command response or notification,
         *   handle those that need handling via function in
         *   rx_handlers table.  See iwl_setup_rx_handlers() */
        if (priv->rx_handlers[pkt->hdr.cmd]) {
                priv->rx_handlers_stats[pkt->hdr.cmd]++;
                priv->rx_handlers[pkt->hdr.cmd](priv, rxb);
        } else {
                /* No handling needed */
                IWL_DEBUG_RX(priv, "No handler needed for %s, 0x%02x\n",
                             iwl_get_cmd_string(priv->trans,
                                                iwl_cmd_id(pkt->hdr.cmd,
                                                           0, 0)),
                             pkt->hdr.cmd);
        }
}