text: /******************************************************************************
   *
   * Copyright(c) 2003 - 2011 Intel Corporation. All rights reserved.
   *
   * Portions of this file are derived from the ipw3945 project, as well
   * as portions 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 <ilw@linux.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-eeprom.h"
  #include "iwl-dev.h"
  #include "iwl-core.h"
  #include "iwl-sta.h"
  #include "iwl-io.h"
  #include "iwl-helpers.h"
  #include "iwl-agn-calib.h"
  #include "iwl-agn.h"
  
  /******************************************************************************
   *
   * RX path functions
   *
   ******************************************************************************/
  
  /*
   * Rx theory of operation
   *
   * Driver allocates a circular buffer of Receive Buffer Descriptors (RBDs),
   * each of which point to Receive Buffers to be filled by the NIC.  These get
   * used not only for Rx frames, but for any command response or notification
   * from the NIC.  The driver and NIC manage the Rx buffers by means
   * of indexes into the circular buffer.
   *
   * Rx Queue Indexes
   * The host/firmware share two index registers for managing the Rx buffers.
   *
   * The READ index maps to the first position that the firmware may be writing
   * to -- the driver can read up to (but not including) this position and get
   * good data.
   * The READ index is managed by the firmware once the card is enabled.
   *
   * The WRITE index maps to the last position the driver has read from -- the
   * position preceding WRITE is the last slot the firmware can place a packet.
   *
   * The queue is empty (no good data) if WRITE = READ - 1, and is full if
   * WRITE = READ.
   *
   * During initialization, the host sets up the READ queue position to the first
   * INDEX position, and WRITE to the last (READ - 1 wrapped)
   *
   * When the firmware places a packet in a buffer, it will advance the READ index
   * and fire the RX interrupt.  The driver can then query the READ index and
   * process as many packets as possible, moving the WRITE index forward as it
   * resets the Rx queue buffers with new memory.
   *
   * The management in the driver is as follows:
   * + A list of pre-allocated SKBs is stored in iwl->rxq->rx_free.  When
   *   iwl->rxq->free_count drops to or below RX_LOW_WATERMARK, work is scheduled
   *   to replenish the iwl->rxq->rx_free.
   * + In iwl_rx_replenish (scheduled) if 'processed' != 'read' then the
   *   iwl->rxq is replenished and the READ INDEX is updated (updating the
   *   'processed' and 'read' driver indexes as well)
   * + A received packet is processed and handed to the kernel network stack,
   *   detached from the iwl->rxq.  The driver 'processed' index is updated.
   * + The Host/Firmware iwl->rxq is replenished at tasklet time from the rx_free
   *   list. If there are no allocated buffers in iwl->rxq->rx_free, the READ
   *   INDEX is not incremented and iwl->status(RX_STALLED) is set.  If there
   *   were enough free buffers and RX_STALLED is set it is cleared.
   *
   *
   * Driver sequence:
   *
   * iwl_rx_queue_alloc()   Allocates rx_free
   * iwl_rx_replenish()     Replenishes rx_free list from rx_used, and calls
   *                            iwl_rx_queue_restock
   * iwl_rx_queue_restock() Moves available buffers from rx_free into Rx
   *                            queue, updates firmware pointers, and updates
   *                            the WRITE index.  If insufficient rx_free buffers
   *                            are available, schedules iwl_rx_replenish
   *
   * -- enable interrupts --
   * ISR - iwl_rx()         Detach iwl_rx_mem_buffers from pool up to the
   *                            READ INDEX, detaching the SKB from the pool.
   *                            Moves the packet buffer from queue to rx_used.
   *                            Calls iwl_rx_queue_restock to refill any empty
   *                            slots.
   * ...
   *
   */
  
  /**
   * iwl_rx_queue_space - Return number of free slots available in queue.
   */
  int iwl_rx_queue_space(const struct iwl_rx_queue *q)
  {
  	int s = q->read - q->write;
  	if (s <= 0)
  		s += RX_QUEUE_SIZE;
  	/* keep some buffer to not confuse full and empty queue */
  	s -= 2;
  	if (s < 0)
  		s = 0;
  	return s;
  }
  
  /**
   * iwl_rx_queue_update_write_ptr - Update the write pointer for the RX queue
   */
  void iwl_rx_queue_update_write_ptr(struct iwl_priv *priv, struct iwl_rx_queue *q)
  {
  	unsigned long flags;
  	u32 rx_wrt_ptr_reg = priv->hw_params.rx_wrt_ptr_reg;
  	u32 reg;
  
  	spin_lock_irqsave(&q->lock, flags);
  
  	if (q->need_update == 0)
  		goto exit_unlock;
  
  	if (priv->cfg->base_params->shadow_reg_enable) {
  		/* shadow register enabled */
  		/* Device expects a multiple of 8 */
  		q->write_actual = (q->write & ~0x7);
  		iwl_write32(priv, rx_wrt_ptr_reg, q->write_actual);
  	} else {
  		/* If power-saving is in use, make sure device is awake */
  		if (test_bit(STATUS_POWER_PMI, &priv->status)) {
  			reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);
  
  			if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
  				IWL_DEBUG_INFO(priv,
  					"Rx queue requesting wakeup,"
  					" GP1 = 0x%x\n", reg);
  				iwl_set_bit(priv, CSR_GP_CNTRL,
  					CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
  				goto exit_unlock;
  			}
  
  			q->write_actual = (q->write & ~0x7);
  			iwl_write_direct32(priv, rx_wrt_ptr_reg,
  					q->write_actual);
  
  		/* Else device is assumed to be awake */
  		} else {
  			/* Device expects a multiple of 8 */
  			q->write_actual = (q->write & ~0x7);
  			iwl_write_direct32(priv, rx_wrt_ptr_reg,
  				q->write_actual);
  		}
  	}
  	q->need_update = 0;
  
   exit_unlock:
  	spin_unlock_irqrestore(&q->lock, flags);
  }
  
  int iwl_rx_queue_alloc(struct iwl_priv *priv)
  {
  	struct iwl_rx_queue *rxq = &priv->rxq;
  	struct device *dev = &priv->pci_dev->dev;
  	int i;
  
  	spin_lock_init(&rxq->lock);
  	INIT_LIST_HEAD(&rxq->rx_free);
  	INIT_LIST_HEAD(&rxq->rx_used);
  
  	/* Alloc the circular buffer of Read Buffer Descriptors (RBDs) */
  	rxq->bd = dma_alloc_coherent(dev, 4 * RX_QUEUE_SIZE, &rxq->bd_dma,
  				     GFP_KERNEL);
  	if (!rxq->bd)
  		goto err_bd;
  
  	rxq->rb_stts = dma_alloc_coherent(dev, sizeof(struct iwl_rb_status),
  					  &rxq->rb_stts_dma, GFP_KERNEL);
  	if (!rxq->rb_stts)
  		goto err_rb;
  
  	/* Fill the rx_used queue with _all_ of the Rx buffers */
  	for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++)
  		list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
  
  	/* Set us so that we have processed and used all buffers, but have
  	 * not restocked the Rx queue with fresh buffers */
  	rxq->read = rxq->write = 0;
  	rxq->write_actual = 0;
  	rxq->free_count = 0;
  	rxq->need_update = 0;
  	return 0;
  
  err_rb:
  	dma_free_coherent(&priv->pci_dev->dev, 4 * RX_QUEUE_SIZE, rxq->bd,
  			  rxq->bd_dma);
  err_bd:
  	return -ENOMEM;
  }
  
  /******************************************************************************
   *
   * Generic RX handler implementations
   *
   ******************************************************************************/
  
  static void iwl_rx_reply_error(struct iwl_priv *priv,
  			       struct iwl_rx_mem_buffer *rxb)
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  
  	IWL_ERR(priv, "Error Reply type 0x%08X cmd %s (0x%02X) "
  		"seq 0x%04X ser 0x%08X\n",
  		le32_to_cpu(pkt->u.err_resp.error_type),
  		get_cmd_string(pkt->u.err_resp.cmd_id),
  		pkt->u.err_resp.cmd_id,
  		le16_to_cpu(pkt->u.err_resp.bad_cmd_seq_num),
  		le32_to_cpu(pkt->u.err_resp.error_info));
  }
  
  static void iwl_rx_csa(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  	struct iwl_csa_notification *csa = &(pkt->u.csa_notif);
  	/*
  	 * MULTI-FIXME
  	 * See iwl_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 iwl_rx_spectrum_measure_notif(struct iwl_priv *priv,
  					  struct iwl_rx_mem_buffer *rxb)
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  	struct iwl_spectrum_notification *report = &(pkt->u.spectrum_notif);
  
  	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 iwl_rx_pm_sleep_notif(struct iwl_priv *priv,
  				  struct iwl_rx_mem_buffer *rxb)
  {
  #ifdef CONFIG_IWLWIFI_DEBUG
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  	struct iwl_sleep_notification *sleep = &(pkt->u.sleep_notif);
  	IWL_DEBUG_RX(priv, "sleep mode: %d, src: %d\n",
  		     sleep->pm_sleep_mode, sleep->pm_wakeup_src);
  #endif
  }
  
  static void iwl_rx_pm_debug_statistics_notif(struct iwl_priv *priv,
  					     struct iwl_rx_mem_buffer *rxb)
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  	u32 len = le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK;
  	IWL_DEBUG_RADIO(priv, "Dumping %d bytes of unhandled "
  			"notification for %s:\n", len,
  			get_cmd_string(pkt->hdr.cmd));
  	iwl_print_hex_dump(priv, IWL_DL_RADIO, pkt->u.raw, len);
  }
  
  static void iwl_rx_beacon_notif(struct iwl_priv *priv,
  				struct iwl_rx_mem_buffer *rxb)
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  	struct iwlagn_beacon_notif *beacon = (void *)pkt->u.raw;
  #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);
  
  	if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
  		queue_work(priv->workqueue, &priv->beacon_update);
  }
  
  /* the threshold ratio of actual_ack_cnt to expected_ack_cnt in percent */
  #define ACK_CNT_RATIO (50)
  #define BA_TIMEOUT_CNT (5)
  #define BA_TIMEOUT_MAX (16)
  
  /**
   * iwl_good_ack_health - checks for ACK count ratios, BA timeout retries.
   *
   * When the ACK count ratio is low and aggregated BA timeout retries exceeding
   * the BA_TIMEOUT_MAX, reload firmware and bring system back to normal
   * operation state.
   */
  static bool iwl_good_ack_health(struct iwl_priv *priv,
  				struct statistics_tx *cur)
  {
  	int actual_delta, expected_delta, ba_timeout_delta;
  	struct statistics_tx *old;
  
  	if (priv->_agn.agg_tids_count)
  		return true;
  
  	old = &priv->statistics.tx;
  
  	actual_delta = le32_to_cpu(cur->actual_ack_cnt) -
  		       le32_to_cpu(old->actual_ack_cnt);
  	expected_delta = le32_to_cpu(cur->expected_ack_cnt) -
  			 le32_to_cpu(old->expected_ack_cnt);
  
  	/* Values should not be negative, but we do not trust the firmware */
  	if (actual_delta <= 0 || expected_delta <= 0)
  		return true;
  
  	ba_timeout_delta = le32_to_cpu(cur->agg.ba_timeout) -
  			   le32_to_cpu(old->agg.ba_timeout);
  
  	if ((actual_delta * 100 / expected_delta) < ACK_CNT_RATIO &&
  	    ba_timeout_delta > BA_TIMEOUT_CNT) {
  		IWL_DEBUG_RADIO(priv, "deltas: actual %d expected %d ba_timeout %d\n",
  				actual_delta, expected_delta, ba_timeout_delta);
  
  #ifdef CONFIG_IWLWIFI_DEBUGFS
  		/*
  		 * This is ifdef'ed on DEBUGFS because otherwise the
  		 * statistics aren't available. If DEBUGFS is set but
  		 * DEBUG is not, these will just compile out.
  		 */
  		IWL_DEBUG_RADIO(priv, "rx_detected_cnt delta %d\n",
  				priv->delta_stats.tx.rx_detected_cnt);
  		IWL_DEBUG_RADIO(priv,
  				"ack_or_ba_timeout_collision delta %d\n",
  				priv->delta_stats.tx.ack_or_ba_timeout_collision);
  #endif
  
  		if (ba_timeout_delta >= BA_TIMEOUT_MAX)
  			return false;
  	}
  
  	return true;
  }
  
  /**
   * 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 iwl_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->cfg->base_params->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;
  }
  
  static void iwl_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_mod_params.ack_check && !iwl_good_ack_health(priv, tx)) {
  		IWL_ERR(priv, "low ack count detected, restart firmware\n");
  		if (!iwl_force_reset(priv, IWL_FW_RESET, false))
  			return;
  	}
  
  	if (iwlagn_mod_params.plcp_check &&
  	    !iwl_good_plcp_health(priv, cur_ofdm, cur_ofdm_ht, msecs))
  		iwl_force_reset(priv, IWL_RF_RESET, 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 iwl_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
  iwl_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
  iwl_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 iwl_rx_statistics(struct iwl_priv *priv,
  			      struct iwl_rx_mem_buffer *rxb)
  {
  	unsigned long stamp = jiffies;
  	const int reg_recalib_period = 60;
  	int change;
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  	u32 len = le32_to_cpu(pkt->len_n_flags) & FH_RSCSR_FRAME_SIZE_MSK;
  	__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;
  
  	len -= sizeof(struct iwl_cmd_header); /* skip header */
  
  	IWL_DEBUG_RX(priv, "Statistics notification received (%d bytes).\n",
  		     len);
  
  	if (len == sizeof(struct iwl_bt_notif_statistics)) {
  		struct iwl_bt_notif_statistics *stats;
  		stats = &pkt->u.stats_bt;
  		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 = &pkt->u.stats;
  		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));
  		return;
  	}
  
  	change = common->temperature != priv->statistics.common.temperature ||
  		 (*flag & STATISTICS_REPLY_FLG_HT40_MODE_MSK) !=
  		 (priv->statistics.flag & STATISTICS_REPLY_FLG_HT40_MODE_MSK);
  
  	iwl_accumulative_statistics(priv, common, rx_non_phy, rx_ofdm,
  				    rx_ofdm_ht, rx_cck, tx, bt_activity);
  
  	iwl_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)) {
  		iwl_rx_calc_noise(priv);
  		queue_work(priv->workqueue, &priv->run_time_calib_work);
  	}
  	if (priv->cfg->ops->lib->temp_ops.temperature && change)
  		priv->cfg->ops->lib->temp_ops.temperature(priv);
  }
  
  static void iwl_rx_reply_statistics(struct iwl_priv *priv,
  				    struct iwl_rx_mem_buffer *rxb)
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  
  	if (le32_to_cpu(pkt->u.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");
  	}
  	iwl_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 iwl_rx_card_state_notif(struct iwl_priv *priv,
  				    struct iwl_rx_mem_buffer *rxb)
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  	u32 flags = le32_to_cpu(pkt->u.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, CSR_UCODE_DRV_GP1_SET,
  			    CSR_UCODE_DRV_GP1_BIT_CMD_BLOCKED);
  
  		iwl_write_direct32(priv, HBUS_TARG_MBX_C,
  					HBUS_TARG_MBX_C_REG_BIT_CMD_BLOCKED);
  
  		if (!(flags & RXON_CARD_DISABLED)) {
  			iwl_write32(priv, CSR_UCODE_DRV_GP1_CLR,
  				    CSR_UCODE_DRV_GP1_BIT_CMD_BLOCKED);
  			iwl_write_direct32(priv, 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));
  	else
  		wake_up_interruptible(&priv->wait_command_queue);
  }
  
  static void iwl_rx_missed_beacon_notif(struct iwl_priv *priv,
  				       struct iwl_rx_mem_buffer *rxb)
  
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  	struct iwl_missed_beacon_notif *missed_beacon;
  
  	missed_beacon = &pkt->u.missed_beacon;
  	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 iwl_rx_reply_rx_phy(struct iwl_priv *priv,
  				struct iwl_rx_mem_buffer *rxb)
  {
  	struct iwl_rx_packet *pkt = rxb_addr(rxb);
  
  	priv->_agn.last_phy_res_valid = true;
  	memcpy(&priv->_agn.last_phy_res, pkt->u.raw,
  	       sizeof(struct iwl_rx_phy_res));
  }
  
  /*
   * returns non-zero if packet should be dropped
   */
  static int iwl_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 iwl_pass_packet_to_mac80211(struct iwl_priv *priv,
  					struct ieee80211_hdr *hdr,
  					u16 len,
  					u32 ampdu_status,
  					struct iwl_rx_mem_buffer *rxb,
  					struct ieee80211_rx_status *stats)
  {
  	struct sk_buff *skb;
  	__le16 fc = hdr->frame_control;
  	struct iwl_rxon_context *ctx;
  
  	/* 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 (!iwlagn_mod_params.sw_crypto &&
  	    iwl_set_decrypted_flag(priv, hdr, ampdu_status, stats))
  		return;
  
  	skb = dev_alloc_skb(128);
  	if (!skb) {
  		IWL_ERR(priv, "dev_alloc_skb failed\n");
  		return;
  	}
  
  	skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb), len);
  
  	iwl_update_stats(priv, false, fc, len);
  
  	/*
  	* 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))) {
  		for_each_context(priv, ctx) {
  			if (!ctx->last_tx_rejected)
  				continue;
  			if (compare_ether_addr(hdr->addr3,
  					       ctx->active.bssid_addr))
  				continue;
  			ctx->last_tx_rejected = false;
  			iwl_wake_any_queue(priv, ctx);
  		}
  	}
  
  	memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
  
  	ieee80211_rx(priv->hw, skb);
  	rxb->page = NULL;
  }
  
  static u32 iwl_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;
  }
  
  /* Called for REPLY_RX (legacy ABG frames), or
   * REPLY_RX_MPDU_CMD (HT high-throughput N frames). */
  static void iwl_rx_reply_rx(struct iwl_priv *priv,
  			    struct iwl_rx_mem_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;
  
  	/**
  	 * REPLY_RX and REPLY_RX_MPDU_CMD are handled differently.
  	 *	REPLY_RX: physical layer info is in this buffer
  	 *	REPLY_RX_MPDU_CMD: physical layer info was sent in separate
  	 *		command and cached in priv->last_phy_res
  	 *
  	 * Here we set up local variables depending on which command is
  	 * received.
  	 */
  	if (pkt->hdr.cmd == REPLY_RX) {
  		phy_res = (struct iwl_rx_phy_res *)pkt->u.raw;
  		header = (struct ieee80211_hdr *)(pkt->u.raw + sizeof(*phy_res)
  				+ phy_res->cfg_phy_cnt);
  
  		len = le16_to_cpu(phy_res->byte_count);
  		rx_pkt_status = *(__le32 *)(pkt->u.raw + sizeof(*phy_res) +
  				phy_res->cfg_phy_cnt + len);
  		ampdu_status = le32_to_cpu(rx_pkt_status);
  	} else {
  		if (!priv->_agn.last_phy_res_valid) {
  			IWL_ERR(priv, "MPDU frame without cached PHY data\n");
  			return;
  		}
  		phy_res = &priv->_agn.last_phy_res;
  		amsdu = (struct iwl_rx_mpdu_res_start *)pkt->u.raw;
  		header = (struct ieee80211_hdr *)(pkt->u.raw + sizeof(*amsdu));
  		len = le16_to_cpu(amsdu->byte_count);
  		rx_pkt_status = *(__le32 *)(pkt->u.raw + sizeof(*amsdu) + len);
  		ampdu_status = iwl_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) ?
  				IEEE80211_BAND_2GHZ : IEEE80211_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_MPDU;*/
  
  	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 = priv->cfg->ops->utils->calc_rssi(priv, phy_res);
  
  	iwl_dbg_log_rx_data_frame(priv, len, header);
  	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;
  
  	/* 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;
  
  	iwl_pass_packet_to_mac80211(priv, header, len, ampdu_status,
  				    rxb, &rx_status);
  }
  
  /**
   * 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_mem_buffer *rxb);
  
  	handlers = priv->rx_handlers;
  
  	handlers[REPLY_ERROR]			= iwl_rx_reply_error;
  	handlers[CHANNEL_SWITCH_NOTIFICATION]	= iwl_rx_csa;
  	handlers[SPECTRUM_MEASURE_NOTIFICATION]	= iwl_rx_spectrum_measure_notif;
  	handlers[PM_SLEEP_NOTIFICATION]		= iwl_rx_pm_sleep_notif;
  	handlers[PM_DEBUG_STATISTIC_NOTIFIC]	= iwl_rx_pm_debug_statistics_notif;
  	handlers[BEACON_NOTIFICATION]		= iwl_rx_beacon_notif;
  
  	/*
  	 * 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]		= iwl_rx_reply_statistics;
  	handlers[STATISTICS_NOTIFICATION]	= iwl_rx_statistics;
  
  	iwl_setup_rx_scan_handlers(priv);
  
  	handlers[CARD_STATE_NOTIFICATION]	= iwl_rx_card_state_notif;
  	handlers[MISSED_BEACONS_NOTIFICATION]	= iwl_rx_missed_beacon_notif;
  
  	/* Rx handlers */
  	handlers[REPLY_RX_PHY_CMD]		= iwl_rx_reply_rx_phy;
  	handlers[REPLY_RX_MPDU_CMD]		= iwl_rx_reply_rx;
  
  	/* block ack */
  	handlers[REPLY_COMPRESSED_BA]		= iwlagn_rx_reply_compressed_ba;
  
  	/* Set up hardware specific Rx handlers */
  	priv->cfg->ops->lib->rx_handler_setup(priv);
  }
  