/******************************************************************************
 *
 * 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
 *
 *****************************************************************************/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/pci-aspm.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/firmware.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>

#include <net/mac80211.h>

#include <asm/div64.h>

#define DRV_NAME        "iwl4965"

#include "common.h"
#include "4965.h"

/******************************************************************************
 *
 * module boiler plate
 *
 ******************************************************************************/

/*
 * module name, copyright, version, etc.
 */
#define DRV_DESCRIPTION "Intel(R) Wireless WiFi 4965 driver for Linux"

#ifdef CONFIG_IWLEGACY_DEBUG
#define VD "d"
#else
#define VD
#endif

#define DRV_VERSION     IWLWIFI_VERSION VD

MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR(DRV_COPYRIGHT " " DRV_AUTHOR);
MODULE_LICENSE("GPL");
MODULE_ALIAS("iwl4965");

void
il4965_check_abort_status(struct il_priv *il, u8 frame_count, u32 status)
{
        if (frame_count == 1 && status == TX_STATUS_FAIL_RFKILL_FLUSH) {
                IL_ERR("Tx flush command to flush out all frames\n");
                if (!test_bit(S_EXIT_PENDING, &il->status))
                        queue_work(il->workqueue, &il->tx_flush);
        }
}

/*
 * EEPROM
 */
struct il_mod_params il4965_mod_params = {
        .amsdu_size_8K = 1,
        .restart_fw = 1,
        /* the rest are 0 by default */
};

void
il4965_rx_queue_reset(struct il_priv *il, struct il_rx_queue *rxq)
{
        unsigned long flags;
        int i;
        spin_lock_irqsave(&rxq->lock, flags);
        INIT_LIST_HEAD(&rxq->rx_free);
        INIT_LIST_HEAD(&rxq->rx_used);
        /* Fill the rx_used queue with _all_ of the Rx buffers */
        for (i = 0; i < RX_FREE_BUFFERS + RX_QUEUE_SIZE; i++) {
                /* In the reset function, these buffers may have been allocated
                 * to an SKB, so we need to unmap and free potential storage */
                if (rxq->pool[i].page != NULL) {
                        pci_unmap_page(il->pci_dev, rxq->pool[i].page_dma,
                                       PAGE_SIZE << il->hw_params.rx_page_order,
                                       PCI_DMA_FROMDEVICE);
                        __il_free_pages(il, rxq->pool[i].page);
                        rxq->pool[i].page = NULL;
                }
                list_add_tail(&rxq->pool[i].list, &rxq->rx_used);
        }

        for (i = 0; i < RX_QUEUE_SIZE; i++)
                rxq->queue[i] = NULL;

        /* 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;
        spin_unlock_irqrestore(&rxq->lock, flags);
}

int
il4965_rx_init(struct il_priv *il, struct il_rx_queue *rxq)
{
        u32 rb_size;
        const u32 rfdnlog = RX_QUEUE_SIZE_LOG;  /* 256 RBDs */
        u32 rb_timeout = 0;

        if (il->cfg->mod_params->amsdu_size_8K)
                rb_size = FH49_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_8K;
        else
                rb_size = FH49_RCSR_RX_CONFIG_REG_VAL_RB_SIZE_4K;

        /* Stop Rx DMA */
        il_wr(il, FH49_MEM_RCSR_CHNL0_CONFIG_REG, 0);

        /* Reset driver's Rx queue write idx */
        il_wr(il, FH49_RSCSR_CHNL0_RBDCB_WPTR_REG, 0);

        /* Tell device where to find RBD circular buffer in DRAM */
        il_wr(il, FH49_RSCSR_CHNL0_RBDCB_BASE_REG, (u32) (rxq->bd_dma >> 8));

        /* Tell device where in DRAM to update its Rx status */
        il_wr(il, FH49_RSCSR_CHNL0_STTS_WPTR_REG, rxq->rb_stts_dma >> 4);

        /* Enable Rx DMA
         * Direct rx interrupts to hosts
         * Rx buffer size 4 or 8k
         * RB timeout 0x10
         * 256 RBDs
         */
        il_wr(il, FH49_MEM_RCSR_CHNL0_CONFIG_REG,
              FH49_RCSR_RX_CONFIG_CHNL_EN_ENABLE_VAL |
              FH49_RCSR_CHNL0_RX_CONFIG_IRQ_DEST_INT_HOST_VAL |
              FH49_RCSR_CHNL0_RX_CONFIG_SINGLE_FRAME_MSK |
              rb_size |
              (rb_timeout << FH49_RCSR_RX_CONFIG_REG_IRQ_RBTH_POS) |
              (rfdnlog << FH49_RCSR_RX_CONFIG_RBDCB_SIZE_POS));

        /* Set interrupt coalescing timer to default (2048 usecs) */
        il_write8(il, CSR_INT_COALESCING, IL_HOST_INT_TIMEOUT_DEF);

        return 0;
}

static void
il4965_set_pwr_vmain(struct il_priv *il)
{
/*
 * (for documentation purposes)
 * to set power to V_AUX, do:

                if (pci_pme_capable(il->pci_dev, PCI_D3cold))
                        il_set_bits_mask_prph(il, APMG_PS_CTRL_REG,
                                               APMG_PS_CTRL_VAL_PWR_SRC_VAUX,
                                               ~APMG_PS_CTRL_MSK_PWR_SRC);
 */

        il_set_bits_mask_prph(il, APMG_PS_CTRL_REG,
                              APMG_PS_CTRL_VAL_PWR_SRC_VMAIN,
                              ~APMG_PS_CTRL_MSK_PWR_SRC);
}

int
il4965_hw_nic_init(struct il_priv *il)
{
        unsigned long flags;
        struct il_rx_queue *rxq = &il->rxq;
        int ret;

        spin_lock_irqsave(&il->lock, flags);
        il_apm_init(il);
        /* Set interrupt coalescing calibration timer to default (512 usecs) */
        il_write8(il, CSR_INT_COALESCING, IL_HOST_INT_CALIB_TIMEOUT_DEF);
        spin_unlock_irqrestore(&il->lock, flags);

        il4965_set_pwr_vmain(il);
        il4965_nic_config(il);

        /* Allocate the RX queue, or reset if it is already allocated */
        if (!rxq->bd) {
                ret = il_rx_queue_alloc(il);
                if (ret) {
                        IL_ERR("Unable to initialize Rx queue\n");
                        return -ENOMEM;
                }
        } else
                il4965_rx_queue_reset(il, rxq);

        il4965_rx_replenish(il);

        il4965_rx_init(il, rxq);

        spin_lock_irqsave(&il->lock, flags);

        rxq->need_update = 1;
        il_rx_queue_update_write_ptr(il, rxq);

        spin_unlock_irqrestore(&il->lock, flags);

        /* Allocate or reset and init all Tx and Command queues */
        if (!il->txq) {
                ret = il4965_txq_ctx_alloc(il);
                if (ret)
                        return ret;
        } else
                il4965_txq_ctx_reset(il);

        set_bit(S_INIT, &il->status);

        return 0;
}

/**
 * il4965_dma_addr2rbd_ptr - convert a DMA address to a uCode read buffer ptr
 */
static inline __le32
il4965_dma_addr2rbd_ptr(struct il_priv *il, dma_addr_t dma_addr)
{
        return cpu_to_le32((u32) (dma_addr >> 8));
}

/**
 * il4965_rx_queue_restock - refill RX queue from pre-allocated pool
 *
 * If there are slots in the RX queue that need to be restocked,
 * and we have free pre-allocated buffers, fill the ranks as much
 * as we can, pulling from rx_free.
 *
 * This moves the 'write' idx forward to catch up with 'processed', and
 * also updates the memory address in the firmware to reference the new
 * target buffer.
 */
void
il4965_rx_queue_restock(struct il_priv *il)
{
        struct il_rx_queue *rxq = &il->rxq;
        struct list_head *element;
        struct il_rx_buf *rxb;
        unsigned long flags;

        spin_lock_irqsave(&rxq->lock, flags);
        while (il_rx_queue_space(rxq) > 0 && rxq->free_count) {
                /* The overwritten rxb must be a used one */
                rxb = rxq->queue[rxq->write];
                BUG_ON(rxb && rxb->page);

                /* Get next free Rx buffer, remove from free list */
                element = rxq->rx_free.next;
                rxb = list_entry(element, struct il_rx_buf, list);
                list_del(element);

                /* Point to Rx buffer via next RBD in circular buffer */
                rxq->bd[rxq->write] =
                    il4965_dma_addr2rbd_ptr(il, rxb->page_dma);
                rxq->queue[rxq->write] = rxb;
                rxq->write = (rxq->write + 1) & RX_QUEUE_MASK;
                rxq->free_count--;
        }
        spin_unlock_irqrestore(&rxq->lock, flags);
        /* If the pre-allocated buffer pool is dropping low, schedule to
         * refill it */
        if (rxq->free_count <= RX_LOW_WATERMARK)
                queue_work(il->workqueue, &il->rx_replenish);

        /* If we've added more space for the firmware to place data, tell it.
         * Increment device's write pointer in multiples of 8. */
        if (rxq->write_actual != (rxq->write & ~0x7)) {
                spin_lock_irqsave(&rxq->lock, flags);
                rxq->need_update = 1;
                spin_unlock_irqrestore(&rxq->lock, flags);
                il_rx_queue_update_write_ptr(il, rxq);
        }
}

/**
 * il4965_rx_replenish - Move all used packet from rx_used to rx_free
 *
 * When moving to rx_free an SKB is allocated for the slot.
 *
 * Also restock the Rx queue via il_rx_queue_restock.
 * This is called as a scheduled work item (except for during initialization)
 */
static void
il4965_rx_allocate(struct il_priv *il, gfp_t priority)
{
        struct il_rx_queue *rxq = &il->rxq;
        struct list_head *element;
        struct il_rx_buf *rxb;
        struct page *page;
        dma_addr_t page_dma;
        unsigned long flags;
        gfp_t gfp_mask = priority;

        while (1) {
                spin_lock_irqsave(&rxq->lock, flags);
                if (list_empty(&rxq->rx_used)) {
                        spin_unlock_irqrestore(&rxq->lock, flags);
                        return;
                }
                spin_unlock_irqrestore(&rxq->lock, flags);

                if (rxq->free_count > RX_LOW_WATERMARK)
                        gfp_mask |= __GFP_NOWARN;

                if (il->hw_params.rx_page_order > 0)
                        gfp_mask |= __GFP_COMP;

                /* Alloc a new receive buffer */
                page = alloc_pages(gfp_mask, il->hw_params.rx_page_order);
                if (!page) {
                        if (net_ratelimit())
                                D_INFO("alloc_pages failed, " "order: %d\n",
                                       il->hw_params.rx_page_order);

                        if (rxq->free_count <= RX_LOW_WATERMARK &&
                            net_ratelimit())
                                IL_ERR("Failed to alloc_pages with %s. "
                                       "Only %u free buffers remaining.\n",
                                       priority ==
                                       GFP_ATOMIC ? "GFP_ATOMIC" : "GFP_KERNEL",
                                       rxq->free_count);
                        /* We don't reschedule replenish work here -- we will
                         * call the restock method and if it still needs
                         * more buffers it will schedule replenish */
                        return;
                }

                /* Get physical address of the RB */
                page_dma =
                    pci_map_page(il->pci_dev, page, 0,
                                 PAGE_SIZE << il->hw_params.rx_page_order,
                                 PCI_DMA_FROMDEVICE);
                if (unlikely(pci_dma_mapping_error(il->pci_dev, page_dma))) {
                        __free_pages(page, il->hw_params.rx_page_order);
                        break;
                }

                spin_lock_irqsave(&rxq->lock, flags);

                if (list_empty(&rxq->rx_used)) {
                        spin_unlock_irqrestore(&rxq->lock, flags);
                        pci_unmap_page(il->pci_dev, page_dma,
                                       PAGE_SIZE << il->hw_params.rx_page_order,
                                       PCI_DMA_FROMDEVICE);
                        __free_pages(page, il->hw_params.rx_page_order);
                        return;
                }

                element = rxq->rx_used.next;
                rxb = list_entry(element, struct il_rx_buf, list);
                list_del(element);

                BUG_ON(rxb->page);

                rxb->page = page;
                rxb->page_dma = page_dma;
                list_add_tail(&rxb->list, &rxq->rx_free);
                rxq->free_count++;
                il->alloc_rxb_page++;

                spin_unlock_irqrestore(&rxq->lock, flags);
        }
}

void
il4965_rx_replenish(struct il_priv *il)
{
        unsigned long flags;

        il4965_rx_allocate(il, GFP_KERNEL);

        spin_lock_irqsave(&il->lock, flags);
        il4965_rx_queue_restock(il);
        spin_unlock_irqrestore(&il->lock, flags);
}

void
il4965_rx_replenish_now(struct il_priv *il)
{
        il4965_rx_allocate(il, GFP_ATOMIC);

        il4965_rx_queue_restock(il);
}

/* Assumes that the skb field of the buffers in 'pool' is kept accurate.
 * If an SKB has been detached, the POOL needs to have its SKB set to NULL
 * This free routine walks the list of POOL entries and if SKB is set to
 * non NULL it is unmapped and freed
 */
void
il4965_rx_queue_free(struct il_priv *il, struct il_rx_queue *rxq)
{
        int i;
        for (i = 0; i < RX_QUEUE_SIZE + RX_FREE_BUFFERS; i++) {
                if (rxq->pool[i].page != NULL) {
                        pci_unmap_page(il->pci_dev, rxq->pool[i].page_dma,
                                       PAGE_SIZE << il->hw_params.rx_page_order,
                                       PCI_DMA_FROMDEVICE);
                        __il_free_pages(il, rxq->pool[i].page);
                        rxq->pool[i].page = NULL;
                }
        }

        dma_free_coherent(&il->pci_dev->dev, 4 * RX_QUEUE_SIZE, rxq->bd,
                          rxq->bd_dma);
        dma_free_coherent(&il->pci_dev->dev, sizeof(struct il_rb_status),
                          rxq->rb_stts, rxq->rb_stts_dma);
        rxq->bd = NULL;
        rxq->rb_stts = NULL;
}

int
il4965_rxq_stop(struct il_priv *il)
{
        int ret;

        _il_wr(il, FH49_MEM_RCSR_CHNL0_CONFIG_REG, 0);
        ret = _il_poll_bit(il, FH49_MEM_RSSR_RX_STATUS_REG,
                           FH49_RSSR_CHNL0_RX_STATUS_CHNL_IDLE,
                           FH49_RSSR_CHNL0_RX_STATUS_CHNL_IDLE,
                           1000);
        if (ret < 0)
                IL_ERR("Can't stop Rx DMA.\n");

        return 0;
}

int
il4965_hwrate_to_mac80211_idx(u32 rate_n_flags, enum ieee80211_band band)
{
        int idx = 0;
        int band_offset = 0;

        /* HT rate format: mac80211 wants an MCS number, which is just LSB */
        if (rate_n_flags & RATE_MCS_HT_MSK) {
                idx = (rate_n_flags & 0xff);
                return idx;
                /* Legacy rate format, search for match in table */
        } else {
                if (band == IEEE80211_BAND_5GHZ)
                        band_offset = IL_FIRST_OFDM_RATE;
                for (idx = band_offset; idx < RATE_COUNT_LEGACY; idx++)
                        if (il_rates[idx].plcp == (rate_n_flags & 0xFF))
                                return idx - band_offset;
        }

        return -1;
}

static int
il4965_calc_rssi(struct il_priv *il, struct il_rx_phy_res *rx_resp)
{
        /* data from PHY/DSP regarding signal strength, etc.,
         *   contents are always there, not configurable by host.  */
        struct il4965_rx_non_cfg_phy *ncphy =
            (struct il4965_rx_non_cfg_phy *)rx_resp->non_cfg_phy_buf;
        u32 agc =
            (le16_to_cpu(ncphy->agc_info) & IL49_AGC_DB_MASK) >>
            IL49_AGC_DB_POS;

        u32 valid_antennae =
            (le16_to_cpu(rx_resp->phy_flags) & IL49_RX_PHY_FLAGS_ANTENNAE_MASK)
            >> IL49_RX_PHY_FLAGS_ANTENNAE_OFFSET;
        u8 max_rssi = 0;
        u32 i;

        /* 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. */
        for (i = 0; i < 3; i++)
                if (valid_antennae & (1 << i))
                        max_rssi = max(ncphy->rssi_info[i << 1], max_rssi);

        D_STATS("Rssi In A %d B %d C %d Max %d AGC dB %d\n",
                ncphy->rssi_info[0], ncphy->rssi_info[2], ncphy->rssi_info[4],
                max_rssi, agc);

        /* dBm = max_rssi dB - agc dB - constant.
         * Higher AGC (higher radio gain) means lower signal. */
        return max_rssi - agc - IL4965_RSSI_OFFSET;
}

static u32
il4965_translate_rx_status(struct il_priv *il, 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;
        }

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

        return decrypt_out;
}

static void
il4965_pass_packet_to_mac80211(struct il_priv *il, struct ieee80211_hdr *hdr,
                               u16 len, u32 ampdu_status, struct il_rx_buf *rxb,
                               struct ieee80211_rx_status *stats)
{
        struct sk_buff *skb;
        __le16 fc = hdr->frame_control;

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

        /* In case of HW accelerated crypto and bad decryption, drop */
        if (!il->cfg->mod_params->sw_crypto &&
            il_set_decrypted_flag(il, hdr, ampdu_status, stats))
                return;

        skb = dev_alloc_skb(128);
        if (!skb) {
                IL_ERR("dev_alloc_skb failed\n");
                return;
        }

        skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb), len,
                        len);

        il_update_stats(il, false, fc, len);
        memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));

        ieee80211_rx(il->hw, skb);
        il->alloc_rxb_page--;
        rxb->page = NULL;
}

/* Called for N_RX (legacy ABG frames), or
 * N_RX_MPDU (HT high-throughput N frames). */
void
il4965_hdl_rx(struct il_priv *il, struct il_rx_buf *rxb)
{
        struct ieee80211_hdr *header;
        struct ieee80211_rx_status rx_status = {};
        struct il_rx_pkt *pkt = rxb_addr(rxb);
        struct il_rx_phy_res *phy_res;
        __le32 rx_pkt_status;
        struct il_rx_mpdu_res_start *amsdu;
        u32 len;
        u32 ampdu_status;
        u32 rate_n_flags;

        /**
         * N_RX and N_RX_MPDU are handled differently.
         *      N_RX: physical layer info is in this buffer
         *      N_RX_MPDU: physical layer info was sent in separate
         *              command and cached in il->last_phy_res
         *
         * Here we set up local variables depending on which command is
         * received.
         */
        if (pkt->hdr.cmd == N_RX) {
                phy_res = (struct il_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 (!il->_4965.last_phy_res_valid) {
                        IL_ERR("MPDU frame without cached PHY data\n");
                        return;
                }
                phy_res = &il->_4965.last_phy_res;
                amsdu = (struct il_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 =
                    il4965_translate_rx_status(il, le32_to_cpu(rx_pkt_status));
        }

        if ((unlikely(phy_res->cfg_phy_cnt > 20))) {
                D_DROP("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)) {
                D_RX("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 =
            il4965_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; */

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

        /* Find max signal strength (dBm) among 3 antenna/receiver chains */
        rx_status.signal = il4965_calc_rssi(il, phy_res);

        D_STATS("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;

        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 = il->_4965.ampdu_ref;
        }

        il4965_pass_packet_to_mac80211(il, header, len, ampdu_status, rxb,
                                       &rx_status);
}

/* Cache phy data (Rx signal strength, etc) for HT frame (N_RX_PHY).
 * This will be used later in il_hdl_rx() for N_RX_MPDU. */
void
il4965_hdl_rx_phy(struct il_priv *il, struct il_rx_buf *rxb)
{
        struct il_rx_pkt *pkt = rxb_addr(rxb);
        il->_4965.last_phy_res_valid = true;
        il->_4965.ampdu_ref++;
        memcpy(&il->_4965.last_phy_res, pkt->u.raw,
               sizeof(struct il_rx_phy_res));
}

static int
il4965_get_channels_for_scan(struct il_priv *il, struct ieee80211_vif *vif,
                             enum ieee80211_band band, u8 is_active,
                             u8 n_probes, struct il_scan_channel *scan_ch)
{
        struct ieee80211_channel *chan;
        const struct ieee80211_supported_band *sband;
        const struct il_channel_info *ch_info;
        u16 passive_dwell = 0;
        u16 active_dwell = 0;
        int added, i;
        u16 channel;

        sband = il_get_hw_mode(il, band);
        if (!sband)
                return 0;

        active_dwell = il_get_active_dwell_time(il, band, n_probes);
        passive_dwell = il_get_passive_dwell_time(il, band, vif);

        if (passive_dwell <= active_dwell)
                passive_dwell = active_dwell + 1;

        for (i = 0, added = 0; i < il->scan_request->n_channels; i++) {
                chan = il->scan_request->channels[i];

                if (chan->band != band)
                        continue;

                channel = chan->hw_value;
                scan_ch->channel = cpu_to_le16(channel);

                ch_info = il_get_channel_info(il, band, channel);
                if (!il_is_channel_valid(ch_info)) {
                        D_SCAN("Channel %d is INVALID for this band.\n",
                               channel);
                        continue;
                }

                if (!is_active || il_is_channel_passive(ch_info) ||
                    (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
                        scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
                else
                        scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;

                if (n_probes)
                        scan_ch->type |= IL_SCAN_PROBE_MASK(n_probes);

                scan_ch->active_dwell = cpu_to_le16(active_dwell);
                scan_ch->passive_dwell = cpu_to_le16(passive_dwell);

                /* Set txpower levels to defaults */
                scan_ch->dsp_atten = 110;

                /* NOTE: if we were doing 6Mb OFDM for scans we'd use
                 * power level:
                 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
                 */
                if (band == IEEE80211_BAND_5GHZ)
                        scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
                else
                        scan_ch->tx_gain = ((1 << 5) | (5 << 3));

                D_SCAN("Scanning ch=%d prob=0x%X [%s %d]\n", channel,
                       le32_to_cpu(scan_ch->type),
                       (scan_ch->
                        type & SCAN_CHANNEL_TYPE_ACTIVE) ? "ACTIVE" : "PASSIVE",
                       (scan_ch->
                        type & SCAN_CHANNEL_TYPE_ACTIVE) ? active_dwell :
                       passive_dwell);

                scan_ch++;
                added++;
        }

        D_SCAN("total channels to scan %d\n", added);
        return added;
}

static void
il4965_toggle_tx_ant(struct il_priv *il, u8 *ant, u8 valid)
{
        int i;
        u8 ind = *ant;

        for (i = 0; i < RATE_ANT_NUM - 1; i++) {
                ind = (ind + 1) < RATE_ANT_NUM ? ind + 1 : 0;
                if (valid & BIT(ind)) {
                        *ant = ind;
                        return;
                }
        }
}

int
il4965_request_scan(struct il_priv *il, struct ieee80211_vif *vif)
{
        struct il_host_cmd cmd = {
                .id = C_SCAN,
                .len = sizeof(struct il_scan_cmd),
                .flags = CMD_SIZE_HUGE,
        };
        struct il_scan_cmd *scan;
        u32 rate_flags = 0;
        u16 cmd_len;
        u16 rx_chain = 0;
        enum ieee80211_band band;
        u8 n_probes = 0;
        u8 rx_ant = il->hw_params.valid_rx_ant;
        u8 rate;
        bool is_active = false;
        int chan_mod;
        u8 active_chains;
        u8 scan_tx_antennas = il->hw_params.valid_tx_ant;
        int ret;

        lockdep_assert_held(&il->mutex);

        if (!il->scan_cmd) {
                il->scan_cmd =
                    kmalloc(sizeof(struct il_scan_cmd) + IL_MAX_SCAN_SIZE,
                            GFP_KERNEL);
                if (!il->scan_cmd) {
                        D_SCAN("fail to allocate memory for scan\n");
                        return -ENOMEM;
                }
        }
        scan = il->scan_cmd;
        memset(scan, 0, sizeof(struct il_scan_cmd) + IL_MAX_SCAN_SIZE);

        scan->quiet_plcp_th = IL_PLCP_QUIET_THRESH;
        scan->quiet_time = IL_ACTIVE_QUIET_TIME;

        if (il_is_any_associated(il)) {
                u16 interval;
                u32 extra;
                u32 suspend_time = 100;
                u32 scan_suspend_time = 100;

                D_INFO("Scanning while associated...\n");
                interval = vif->bss_conf.beacon_int;

                scan->suspend_time = 0;
                scan->max_out_time = cpu_to_le32(200 * 1024);
                if (!interval)
                        interval = suspend_time;

                extra = (suspend_time / interval) << 22;
                scan_suspend_time =
                    (extra | ((suspend_time % interval) * 1024));
                scan->suspend_time = cpu_to_le32(scan_suspend_time);
                D_SCAN("suspend_time 0x%X beacon interval %d\n",
                       scan_suspend_time, interval);
        }

        if (il->scan_request->n_ssids) {
                int i, p = 0;
                D_SCAN("Kicking off active scan\n");
                for (i = 0; i < il->scan_request->n_ssids; i++) {
                        /* always does wildcard anyway */
                        if (!il->scan_request->ssids[i].ssid_len)
                                continue;
                        scan->direct_scan[p].id = WLAN_EID_SSID;
                        scan->direct_scan[p].len =
                            il->scan_request->ssids[i].ssid_len;
                        memcpy(scan->direct_scan[p].ssid,
                               il->scan_request->ssids[i].ssid,
                               il->scan_request->ssids[i].ssid_len);
                        n_probes++;
                        p++;
                }
                is_active = true;
        } else
                D_SCAN("Start passive scan.\n");

        scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
        scan->tx_cmd.sta_id = il->hw_params.bcast_id;
        scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;

        switch (il->scan_band) {
        case IEEE80211_BAND_2GHZ:
                scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
                chan_mod =
                    le32_to_cpu(il->active.flags & RXON_FLG_CHANNEL_MODE_MSK) >>
                    RXON_FLG_CHANNEL_MODE_POS;
                if (chan_mod == CHANNEL_MODE_PURE_40) {
                        rate = RATE_6M_PLCP;
                } else {
                        rate = RATE_1M_PLCP;
                        rate_flags = RATE_MCS_CCK_MSK;
                }
                break;
        case IEEE80211_BAND_5GHZ:
                rate = RATE_6M_PLCP;
                break;
        default:
                IL_WARN("Invalid scan band\n");
                return -EIO;
        }

        /*
         * If active scanning is requested but a certain channel is
         * marked passive, we can do active scanning if we detect
         * transmissions.
         *
         * There is an issue with some firmware versions that triggers
         * a sysassert on a "good CRC threshold" of zero (== disabled),
         * on a radar channel even though this means that we should NOT
         * send probes.
         *
         * The "good CRC threshold" is the number of frames that we
         * need to receive during our dwell time on a channel before
         * sending out probes -- setting this to a huge value will
         * mean we never reach it, but at the same time work around
         * the aforementioned issue. Thus use IL_GOOD_CRC_TH_NEVER
         * here instead of IL_GOOD_CRC_TH_DISABLED.
         */
        scan->good_CRC_th =
            is_active ? IL_GOOD_CRC_TH_DEFAULT : IL_GOOD_CRC_TH_NEVER;

        band = il->scan_band;

        if (il->cfg->scan_rx_antennas[band])
                rx_ant = il->cfg->scan_rx_antennas[band];

        il4965_toggle_tx_ant(il, &il->scan_tx_ant[band], scan_tx_antennas);
        rate_flags |= BIT(il->scan_tx_ant[band]) << RATE_MCS_ANT_POS;
        scan->tx_cmd.rate_n_flags = cpu_to_le32(rate | rate_flags);

        /* In power save mode use one chain, otherwise use all chains */
        if (test_bit(S_POWER_PMI, &il->status)) {
                /* rx_ant has been set to all valid chains previously */
                active_chains =
                    rx_ant & ((u8) (il->chain_noise_data.active_chains));
                if (!active_chains)
                        active_chains = rx_ant;

                D_SCAN("chain_noise_data.active_chains: %u\n",
                       il->chain_noise_data.active_chains);

                rx_ant = il4965_first_antenna(active_chains);
        }

        /* MIMO is not used here, but value is required */

        rx_chain |= il->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
        rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
        rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
        rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
        scan->rx_chain = cpu_to_le16(rx_chain);

        cmd_len =
            il_fill_probe_req(il, (struct ieee80211_mgmt *)scan->data,
                              vif->addr, il->scan_request->ie,
                              il->scan_request->ie_len,
                              IL_MAX_SCAN_SIZE - sizeof(*scan));
        scan->tx_cmd.len = cpu_to_le16(cmd_len);

        scan->filter_flags |=
            (RXON_FILTER_ACCEPT_GRP_MSK | RXON_FILTER_BCON_AWARE_MSK);

        scan->channel_count =
            il4965_get_channels_for_scan(il, vif, band, is_active, n_probes,
                                         (void *)&scan->data[cmd_len]);
        if (scan->channel_count == 0) {
                D_SCAN("channel count %d\n", scan->channel_count);
                return -EIO;
        }

        cmd.len +=
            le16_to_cpu(scan->tx_cmd.len) +
            scan->channel_count * sizeof(struct il_scan_channel);
        cmd.data = scan;
        scan->len = cpu_to_le16(cmd.len);

        set_bit(S_SCAN_HW, &il->status);

        ret = il_send_cmd_sync(il, &cmd);
        if (ret)
                clear_bit(S_SCAN_HW, &il->status);

        return ret;
}

int
il4965_manage_ibss_station(struct il_priv *il, struct ieee80211_vif *vif,
                           bool add)
{
        struct il_vif_priv *vif_priv = (void *)vif->drv_priv;

        if (add)
                return il4965_add_bssid_station(il, vif->bss_conf.bssid,
                                                &vif_priv->ibss_bssid_sta_id);
        return il_remove_station(il, vif_priv->ibss_bssid_sta_id,
                                 vif->bss_conf.bssid);
}

void
il4965_free_tfds_in_queue(struct il_priv *il, int sta_id, int tid, int freed)
{
        lockdep_assert_held(&il->sta_lock);

        if (il->stations[sta_id].tid[tid].tfds_in_queue >= freed)
                il->stations[sta_id].tid[tid].tfds_in_queue -= freed;
        else {
                D_TX("free more than tfds_in_queue (%u:%d)\n",
                     il->stations[sta_id].tid[tid].tfds_in_queue, freed);
                il->stations[sta_id].tid[tid].tfds_in_queue = 0;
        }
}

#define IL_TX_QUEUE_MSK 0xfffff

static bool
il4965_is_single_rx_stream(struct il_priv *il)
{
        return il->current_ht_config.smps == IEEE80211_SMPS_STATIC ||
            il->current_ht_config.single_chain_sufficient;
}

#define IL_NUM_RX_CHAINS_MULTIPLE       3
#define IL_NUM_RX_CHAINS_SINGLE 2
#define IL_NUM_IDLE_CHAINS_DUAL 2
#define IL_NUM_IDLE_CHAINS_SINGLE       1

/*
 * Determine how many receiver/antenna chains to use.
 *
 * More provides better reception via diversity.  Fewer saves power
 * at the expense of throughput, but only when not in powersave to
 * start with.
 *
 * MIMO (dual stream) requires at least 2, but works better with 3.
 * This does not determine *which* chains to use, just how many.
 */
static int
il4965_get_active_rx_chain_count(struct il_priv *il)
{
        /* # of Rx chains to use when expecting MIMO. */
        if (il4965_is_single_rx_stream(il))
                return IL_NUM_RX_CHAINS_SINGLE;
        else
                return IL_NUM_RX_CHAINS_MULTIPLE;
}

/*
 * When we are in power saving mode, unless device support spatial
 * multiplexing power save, use the active count for rx chain count.
 */
static int
il4965_get_idle_rx_chain_count(struct il_priv *il, int active_cnt)
{
        /* # Rx chains when idling, depending on SMPS mode */
        switch (il->current_ht_config.smps) {
        case IEEE80211_SMPS_STATIC:
        case IEEE80211_SMPS_DYNAMIC:
                return IL_NUM_IDLE_CHAINS_SINGLE;
        case IEEE80211_SMPS_OFF:
                return active_cnt;
        default:
                WARN(1, "invalid SMPS mode %d", il->current_ht_config.smps);
                return active_cnt;
        }
}

/* up to 4 chains */
static u8
il4965_count_chain_bitmap(u32 chain_bitmap)
{
        u8 res;
        res = (chain_bitmap & BIT(0)) >> 0;
        res += (chain_bitmap & BIT(1)) >> 1;
        res += (chain_bitmap & BIT(2)) >> 2;
        res += (chain_bitmap & BIT(3)) >> 3;
        return res;
}

/**
 * il4965_set_rxon_chain - Set up Rx chain usage in "staging" RXON image
 *
 * Selects how many and which Rx receivers/antennas/chains to use.
 * This should not be used for scan command ... it puts data in wrong place.
 */
void
il4965_set_rxon_chain(struct il_priv *il)
{
        bool is_single = il4965_is_single_rx_stream(il);
        bool is_cam = !test_bit(S_POWER_PMI, &il->status);
        u8 idle_rx_cnt, active_rx_cnt, valid_rx_cnt;
        u32 active_chains;
        u16 rx_chain;

        /* Tell uCode which antennas are actually connected.
         * Before first association, we assume all antennas are connected.
         * Just after first association, il4965_chain_noise_calibration()
         *    checks which antennas actually *are* connected. */
        if (il->chain_noise_data.active_chains)
                active_chains = il->chain_noise_data.active_chains;
        else
                active_chains = il->hw_params.valid_rx_ant;

        rx_chain = active_chains << RXON_RX_CHAIN_VALID_POS;

        /* How many receivers should we use? */
        active_rx_cnt = il4965_get_active_rx_chain_count(il);
        idle_rx_cnt = il4965_get_idle_rx_chain_count(il, active_rx_cnt);

        /* correct rx chain count according hw settings
         * and chain noise calibration
         */
        valid_rx_cnt = il4965_count_chain_bitmap(active_chains);
        if (valid_rx_cnt < active_rx_cnt)
                active_rx_cnt = valid_rx_cnt;

        if (valid_rx_cnt < idle_rx_cnt)
                idle_rx_cnt = valid_rx_cnt;

        rx_chain |= active_rx_cnt << RXON_RX_CHAIN_MIMO_CNT_POS;
        rx_chain |= idle_rx_cnt << RXON_RX_CHAIN_CNT_POS;

        il->staging.rx_chain = cpu_to_le16(rx_chain);

        if (!is_single && active_rx_cnt >= IL_NUM_RX_CHAINS_SINGLE && is_cam)
                il->staging.rx_chain |= RXON_RX_CHAIN_MIMO_FORCE_MSK;
        else
                il->staging.rx_chain &= ~RXON_RX_CHAIN_MIMO_FORCE_MSK;

        D_ASSOC("rx_chain=0x%X active=%d idle=%d\n", il->staging.rx_chain,
                active_rx_cnt, idle_rx_cnt);

        WARN_ON(active_rx_cnt == 0 || idle_rx_cnt == 0 ||
                active_rx_cnt < idle_rx_cnt);
}

static const char *
il4965_get_fh_string(int cmd)
{
        switch (cmd) {
                IL_CMD(FH49_RSCSR_CHNL0_STTS_WPTR_REG);
                IL_CMD(FH49_RSCSR_CHNL0_RBDCB_BASE_REG);
                IL_CMD(FH49_RSCSR_CHNL0_WPTR);
                IL_CMD(FH49_MEM_RCSR_CHNL0_CONFIG_REG);
                IL_CMD(FH49_MEM_RSSR_SHARED_CTRL_REG);
                IL_CMD(FH49_MEM_RSSR_RX_STATUS_REG);
                IL_CMD(FH49_MEM_RSSR_RX_ENABLE_ERR_IRQ2DRV);
                IL_CMD(FH49_TSSR_TX_STATUS_REG);
                IL_CMD(FH49_TSSR_TX_ERROR_REG);
        default:
                return "UNKNOWN";
        }
}

int
il4965_dump_fh(struct il_priv *il, char **buf, bool display)
{
        int i;
#ifdef CONFIG_IWLEGACY_DEBUG
        int pos = 0;
        size_t bufsz = 0;
#endif
        static const u32 fh_tbl[] = {
                FH49_RSCSR_CHNL0_STTS_WPTR_REG,
                FH49_RSCSR_CHNL0_RBDCB_BASE_REG,
                FH49_RSCSR_CHNL0_WPTR,
                FH49_MEM_RCSR_CHNL0_CONFIG_REG,
                FH49_MEM_RSSR_SHARED_CTRL_REG,
                FH49_MEM_RSSR_RX_STATUS_REG,
                FH49_MEM_RSSR_RX_ENABLE_ERR_IRQ2DRV,
                FH49_TSSR_TX_STATUS_REG,
                FH49_TSSR_TX_ERROR_REG
        };
#ifdef CONFIG_IWLEGACY_DEBUG
        if (display) {
                bufsz = ARRAY_SIZE(fh_tbl) * 48 + 40;
                *buf = kmalloc(bufsz, GFP_KERNEL);
                if (!*buf)
                        return -ENOMEM;
                pos +=
                    scnprintf(*buf + pos, bufsz - pos, "FH register values:\n");
                for (i = 0; i < ARRAY_SIZE(fh_tbl); i++) {
                        pos +=
                            scnprintf(*buf + pos, bufsz - pos,
                                      "  %34s: 0X%08x\n",
                                      il4965_get_fh_string(fh_tbl[i]),
                                      il_rd(il, fh_tbl[i]));
                }
                return pos;
        }
#endif
        IL_ERR("FH register values:\n");
        for (i = 0; i < ARRAY_SIZE(fh_tbl); i++) {
                IL_ERR("  %34s: 0X%08x\n", il4965_get_fh_string(fh_tbl[i]),
                       il_rd(il, fh_tbl[i]));
        }
        return 0;
}

void
il4965_hdl_missed_beacon(struct il_priv *il, struct il_rx_buf *rxb)
{
        struct il_rx_pkt *pkt = rxb_addr(rxb);
        struct il_missed_beacon_notif *missed_beacon;

        missed_beacon = &pkt->u.missed_beacon;
        if (le32_to_cpu(missed_beacon->consecutive_missed_beacons) >
            il->missed_beacon_threshold) {
                D_CALIB("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(S_SCANNING, &il->status))
                        il4965_init_sensitivity(il);
        }
}

/* 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
il4965_rx_calc_noise(struct il_priv *il)
{
        struct stats_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 = &(il->_4965.stats.rx.general);
        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 = IL_NOISE_MEAS_NOT_AVAILABLE;

        D_CALIB("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_IWLEGACY_DEBUGFS
/*
 *  based on the assumption of all stats counter are in DWORD
 *  FIXME: This function is for debugging, do not deal with
 *  the case of counters roll-over.
 */
static void
il4965_accumulative_stats(struct il_priv *il, __le32 * stats)
{
        int i, size;
        __le32 *prev_stats;
        u32 *accum_stats;
        u32 *delta, *max_delta;
        struct stats_general_common *general, *accum_general;
        struct stats_tx *tx, *accum_tx;

        prev_stats = (__le32 *) &il->_4965.stats;
        accum_stats = (u32 *) &il->_4965.accum_stats;
        size = sizeof(struct il_notif_stats);
        general = &il->_4965.stats.general.common;
        accum_general = &il->_4965.accum_stats.general.common;
        tx = &il->_4965.stats.tx;
        accum_tx = &il->_4965.accum_stats.tx;
        delta = (u32 *) &il->_4965.delta_stats;
        max_delta = (u32 *) &il->_4965.max_delta;

        for (i = sizeof(__le32); i < size;
             i +=
             sizeof(__le32), stats++, prev_stats++, delta++, max_delta++,
             accum_stats++) {
                if (le32_to_cpu(*stats) > le32_to_cpu(*prev_stats)) {
                        *delta =
                            (le32_to_cpu(*stats) - le32_to_cpu(*prev_stats));
                        *accum_stats += *delta;
                        if (*delta > *max_delta)
                                *max_delta = *delta;
                }
        }

        /* reset accumulative stats for "no-counter" type stats */
        accum_general->temperature = general->temperature;
        accum_general->ttl_timestamp = general->ttl_timestamp;
}
#endif

void
il4965_hdl_stats(struct il_priv *il, struct il_rx_buf *rxb)
{
        const int recalib_seconds = 60;
        bool change;
        struct il_rx_pkt *pkt = rxb_addr(rxb);

        D_RX("Statistics notification received (%d vs %d).\n",
             (int)sizeof(struct il_notif_stats),
             le32_to_cpu(pkt->len_n_flags) & IL_RX_FRAME_SIZE_MSK);

        change =
            ((il->_4965.stats.general.common.temperature !=
              pkt->u.stats.general.common.temperature) ||
             ((il->_4965.stats.flag & STATS_REPLY_FLG_HT40_MODE_MSK) !=
              (pkt->u.stats.flag & STATS_REPLY_FLG_HT40_MODE_MSK)));
#ifdef CONFIG_IWLEGACY_DEBUGFS
        il4965_accumulative_stats(il, (__le32 *) &pkt->u.stats);
#endif

        /* TODO: reading some of stats is unneeded */
        memcpy(&il->_4965.stats, &pkt->u.stats, sizeof(il->_4965.stats));

        set_bit(S_STATS, &il->status);

        /*
         * Reschedule the stats timer to occur in recalib_seconds to ensure
         * we get a thermal update even if the uCode doesn't give us one
         */
        mod_timer(&il->stats_periodic,
                  jiffies + msecs_to_jiffies(recalib_seconds * 1000));

        if (unlikely(!test_bit(S_SCANNING, &il->status)) &&
            (pkt->hdr.cmd == N_STATS)) {
                il4965_rx_calc_noise(il);
                queue_work(il->workqueue, &il->run_time_calib_work);
        }

        if (change)
                il4965_temperature_calib(il);
}

void
il4965_hdl_c_stats(struct il_priv *il, struct il_rx_buf *rxb)
{
        struct il_rx_pkt *pkt = rxb_addr(rxb);

        if (le32_to_cpu(pkt->u.stats.flag) & UCODE_STATS_CLEAR_MSK) {
#ifdef CONFIG_IWLEGACY_DEBUGFS
                memset(&il->_4965.accum_stats, 0,
                       sizeof(struct il_notif_stats));
                memset(&il->_4965.delta_stats, 0,
                       sizeof(struct il_notif_stats));
                memset(&il->_4965.max_delta, 0, sizeof(struct il_notif_stats));
#endif
                D_RX("Statistics have been cleared\n");
        }
        il4965_hdl_stats(il, rxb);
}


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

static const u8 tid_to_ac[] = {
        IEEE80211_AC_BE,
        IEEE80211_AC_BK,
        IEEE80211_AC_BK,
        IEEE80211_AC_BE,
        IEEE80211_AC_VI,
        IEEE80211_AC_VI,
        IEEE80211_AC_VO,
        IEEE80211_AC_VO
};

static inline int
il4965_get_ac_from_tid(u16 tid)
{
        if (likely(tid < ARRAY_SIZE(tid_to_ac)))
                return tid_to_ac[tid];

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

static inline int
il4965_get_fifo_from_tid(u16 tid)
{
        const u8 ac_to_fifo[] = {
                IL_TX_FIFO_VO,
                IL_TX_FIFO_VI,
                IL_TX_FIFO_BE,
                IL_TX_FIFO_BK,
        };

        if (likely(tid < ARRAY_SIZE(tid_to_ac)))
                return ac_to_fifo[tid_to_ac[tid]];

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

/*
 * handle build C_TX command notification.
 */
static void
il4965_tx_cmd_build_basic(struct il_priv *il, struct sk_buff *skb,
                          struct il_tx_cmd *tx_cmd,
                          struct ieee80211_tx_info *info,
                          struct ieee80211_hdr *hdr, u8 std_id)
{
        __le16 fc = hdr->frame_control;
        __le32 tx_flags = tx_cmd->tx_flags;

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

        if (ieee80211_is_back_req(fc))
                tx_flags |= TX_CMD_FLG_ACK_MSK | TX_CMD_FLG_IMM_BA_RSP_MASK;

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

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

        il_tx_cmd_protection(il, info, fc, &tx_flags);

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

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

static void
il4965_tx_cmd_build_rate(struct il_priv *il,
                         struct il_tx_cmd *tx_cmd,
                         struct ieee80211_tx_info *info,
                         struct ieee80211_sta *sta,
                         __le16 fc)
{
        const u8 rts_retry_limit = 60;
        u32 rate_flags;
        int rate_idx;
        u8 data_retry_limit;
        u8 rate_plcp;

        /* Set retry limit on DATA packets and Probe Responses */
        if (ieee80211_is_probe_resp(fc))
                data_retry_limit = 3;
        else
                data_retry_limit = IL4965_DEFAULT_TX_RETRY;
        tx_cmd->data_retry_limit = data_retry_limit;
        /* Set retry limit on RTS packets */
        tx_cmd->rts_retry_limit = min(data_retry_limit, rts_retry_limit);

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

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

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

        /* Set up antennas */
        il4965_toggle_tx_ant(il, &il->mgmt_tx_ant, il->hw_params.valid_tx_ant);
        rate_flags |= BIT(il->mgmt_tx_ant) << RATE_MCS_ANT_POS;

        /* Set the rate in the TX cmd */
        tx_cmd->rate_n_flags = cpu_to_le32(rate_plcp | rate_flags);
}

static void
il4965_tx_cmd_build_hwcrypto(struct il_priv *il, struct ieee80211_tx_info *info,
                             struct il_tx_cmd *tx_cmd, struct sk_buff *skb_frag,
                             int sta_id)
{
        struct ieee80211_key_conf *keyconf = info->control.hw_key;

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

        case WLAN_CIPHER_SUITE_TKIP:
                tx_cmd->sec_ctl = TX_CMD_SEC_TKIP;
                ieee80211_get_tkip_p2k(keyconf, skb_frag, tx_cmd->key);
                D_TX("tx_cmd with tkip hwcrypto\n");
                break;

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

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

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

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

/*
 * start C_TX command process
 */
int
il4965_tx_skb(struct il_priv *il,
              struct ieee80211_sta *sta,
              struct sk_buff *skb)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
        struct il_station_priv *sta_priv = NULL;
        struct il_tx_queue *txq;
        struct il_queue *q;
        struct il_device_cmd *out_cmd;
        struct il_cmd_meta *out_meta;
        struct il_tx_cmd *tx_cmd;
        int txq_id;
        dma_addr_t phys_addr;
        dma_addr_t txcmd_phys;
        dma_addr_t scratch_phys;
        u16 len, firstlen, secondlen;
        u16 seq_number = 0;
        __le16 fc;
        u8 hdr_len;
        u8 sta_id;
        u8 wait_write_ptr = 0;
        u8 tid = 0;
        u8 *qc = NULL;
        unsigned long flags;
        bool is_agg = false;

        spin_lock_irqsave(&il->lock, flags);
        if (il_is_rfkill(il)) {
                D_DROP("Dropping - RF KILL\n");
                goto drop_unlock;
        }

        fc = hdr->frame_control;

#ifdef CONFIG_IWLEGACY_DEBUG
        if (ieee80211_is_auth(fc))
                D_TX("Sending AUTH frame\n");
        else if (ieee80211_is_assoc_req(fc))
                D_TX("Sending ASSOC frame\n");
        else if (ieee80211_is_reassoc_req(fc))
                D_TX("Sending REASSOC frame\n");
#endif

        hdr_len = ieee80211_hdrlen(fc);

        /* For management frames use broadcast id to do not break aggregation */
        if (!ieee80211_is_data(fc))
                sta_id = il->hw_params.bcast_id;
        else {
                /* Find idx into station table for destination station */
                sta_id = il_sta_id_or_broadcast(il, sta);

                if (sta_id == IL_INVALID_STATION) {
                        D_DROP("Dropping - INVALID STATION: %pM\n", hdr->addr1);
                        goto drop_unlock;
                }
        }

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

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

        if (sta_priv && sta_priv->asleep &&
            (info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER)) {
                /*
                 * This sends an asynchronous command to the device,
                 * but we can rely on it being processed before the
                 * next frame is processed -- and the next frame to
                 * this station is the one that will consume this
                 * counter.
                 * For now set the counter to just 1 since we do not
                 * support uAPSD yet.
                 */
                il4965_sta_modify_sleep_tx_count(il, sta_id, 1);
        }

        /* FIXME: remove me ? */
        WARN_ON_ONCE(info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM);

        /* Access category (AC) is also the queue number */
        txq_id = skb_get_queue_mapping(skb);

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

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

        txq = &il->txq[txq_id];
        q = &txq->q;

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

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

        spin_unlock(&il->sta_lock);

        txq->skbs[q->write_ptr] = skb;

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

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

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

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

        if (info->control.hw_key)
                il4965_tx_cmd_build_hwcrypto(il, info, tx_cmd, skb, sta_id);

        /* TODO need this for burst mode later on */
        il4965_tx_cmd_build_basic(il, skb, tx_cmd, info, hdr, sta_id);

        il4965_tx_cmd_build_rate(il, tx_cmd, info, sta, fc);

        /*
         * Use the first empty entry in this queue's command buffer array
         * to contain the Tx command and MAC header concatenated together
         * (payload data will be in another buffer).
         * Size of this varies, due to varying MAC header length.
         * If end is not dword aligned, we'll have 2 extra bytes at the end
         * of the MAC header (device reads on dword boundaries).
         * We'll tell device about this padding later.
         */
        len = sizeof(struct il_tx_cmd) + sizeof(struct il_cmd_header) + hdr_len;
        firstlen = (len + 3) & ~3;

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

        /* Physical address of this Tx command's header (not MAC header!),
         * within command buffer array. */
        txcmd_phys =
            pci_map_single(il->pci_dev, &out_cmd->hdr, firstlen,
                           PCI_DMA_BIDIRECTIONAL);
        if (unlikely(pci_dma_mapping_error(il->pci_dev, txcmd_phys)))
                goto drop_unlock;

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

        /* Add buffer containing Tx command and MAC(!) header to TFD's
         * first entry */
        il->ops->txq_attach_buf_to_tfd(il, txq, txcmd_phys, firstlen, 1, 0);
        dma_unmap_addr_set(out_meta, mapping, txcmd_phys);
        dma_unmap_len_set(out_meta, len, firstlen);
        if (secondlen)
                il->ops->txq_attach_buf_to_tfd(il, txq, phys_addr, secondlen,
                                               0, 0);

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

        scratch_phys =
            txcmd_phys + sizeof(struct il_cmd_header) +
            offsetof(struct il_tx_cmd, scratch);

        /* take back ownership of DMA buffer to enable update */
        pci_dma_sync_single_for_cpu(il->pci_dev, txcmd_phys, firstlen,
                                    PCI_DMA_BIDIRECTIONAL);
        tx_cmd->dram_lsb_ptr = cpu_to_le32(scratch_phys);
        tx_cmd->dram_msb_ptr = il_get_dma_hi_addr(scratch_phys);

        il_update_stats(il, true, fc, skb->len);

        D_TX("sequence nr = 0X%x\n", le16_to_cpu(out_cmd->hdr.sequence));
        D_TX("tx_flags = 0X%x\n", le32_to_cpu(tx_cmd->tx_flags));
        il_print_hex_dump(il, IL_DL_TX, (u8 *) tx_cmd, sizeof(*tx_cmd));
        il_print_hex_dump(il, IL_DL_TX, (u8 *) tx_cmd->hdr, hdr_len);

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

        pci_dma_sync_single_for_device(il->pci_dev, txcmd_phys, firstlen,
                                       PCI_DMA_BIDIRECTIONAL);

        /* Tell device the write idx *just past* this latest filled TFD */
        q->write_ptr = il_queue_inc_wrap(q->write_ptr, q->n_bd);
        il_txq_update_write_ptr(il, txq);
        spin_unlock_irqrestore(&il->lock, flags);

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

        /*
         * Avoid atomic ops if it isn't an associated client.
         * Also, if this is a packet for aggregation, don't
         * increase the counter because the ucode will stop
         * aggregation queues when their respective station
         * goes to sleep.
         */
        if (sta_priv && sta_priv->client && !is_agg)
                atomic_inc(&sta_priv->pending_frames);

        if (il_queue_space(q) < q->high_mark && il->mac80211_registered) {
                if (wait_write_ptr) {
                        spin_lock_irqsave(&il->lock, flags);
                        txq->need_update = 1;
                        il_txq_update_write_ptr(il, txq);
                        spin_unlock_irqrestore(&il->lock, flags);
                } else {
                        il_stop_queue(il, txq);
                }
        }

        return 0;

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

static inline int
il4965_alloc_dma_ptr(struct il_priv *il, struct il_dma_ptr *ptr, size_t size)
{
        ptr->addr =
            dma_alloc_coherent(&il->pci_dev->dev, size, &ptr->dma, GFP_KERNEL);
        if (!ptr->addr)
                return -ENOMEM;
        ptr->size = size;
        return 0;
}

static inline void
il4965_free_dma_ptr(struct il_priv *il, struct il_dma_ptr *ptr)
{
        if (unlikely(!ptr->addr))
                return;

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

/**
 * il4965_hw_txq_ctx_free - Free TXQ Context
 *
 * Destroy all TX DMA queues and structures
 */
void
il4965_hw_txq_ctx_free(struct il_priv *il)
{
        int txq_id;

        /* Tx queues */
        if (il->txq) {
                for (txq_id = 0; txq_id < il->hw_params.max_txq_num; txq_id++)
                        if (txq_id == il->cmd_queue)
                                il_cmd_queue_free(il);
                        else
                                il_tx_queue_free(il, txq_id);
        }
        il4965_free_dma_ptr(il, &il->kw);

        il4965_free_dma_ptr(il, &il->scd_bc_tbls);

        /* free tx queue structure */
        il_free_txq_mem(il);
}

/**
 * il4965_txq_ctx_alloc - allocate TX queue context
 * Allocate all Tx DMA structures and initialize them
 *
 * @param il
 * @return error code
 */
int
il4965_txq_ctx_alloc(struct il_priv *il)
{
        int ret, txq_id;
        unsigned long flags;

        /* Free all tx/cmd queues and keep-warm buffer */
        il4965_hw_txq_ctx_free(il);

        ret =
            il4965_alloc_dma_ptr(il, &il->scd_bc_tbls,
                                 il->hw_params.scd_bc_tbls_size);
        if (ret) {
                IL_ERR("Scheduler BC Table allocation failed\n");
                goto error_bc_tbls;
        }
        /* Alloc keep-warm buffer */
        ret = il4965_alloc_dma_ptr(il, &il->kw, IL_KW_SIZE);
        if (ret) {
                IL_ERR("Keep Warm allocation failed\n");
                goto error_kw;
        }

        /* allocate tx queue structure */
        ret = il_alloc_txq_mem(il);
        if (ret)

                goto error;

        spin_lock_irqsave(&il->lock, flags);

        /* Turn off all Tx DMA fifos */
        il4965_txq_set_sched(il, 0);

        /* Tell NIC where to find the "keep warm" buffer */
        il_wr(il, FH49_KW_MEM_ADDR_REG, il->kw.dma >> 4);

        spin_unlock_irqrestore(&il->lock, flags);

        /* Alloc and init all Tx queues, including the command queue (#4/#9) */
        for (txq_id = 0; txq_id < il->hw_params.max_txq_num; txq_id++) {
                ret = il_tx_queue_init(il, txq_id);
                if (ret) {
                        IL_ERR("Tx %d queue init failed\n", txq_id);
                        goto error;
                }
        }

        return ret;

error:
        il4965_hw_txq_ctx_free(il);
        il4965_free_dma_ptr(il, &il->kw);
error_kw:
        il4965_free_dma_ptr(il, &il->scd_bc_tbls);
error_bc_tbls:
        return ret;
}

void
il4965_txq_ctx_reset(struct il_priv *il)
{
        int txq_id;
        unsigned long flags;

        spin_lock_irqsave(&il->lock, flags);

        /* Turn off all Tx DMA fifos */
        il4965_txq_set_sched(il, 0);
        /* Tell NIC where to find the "keep warm" buffer */
        il_wr(il, FH49_KW_MEM_ADDR_REG, il->kw.dma >> 4);

        spin_unlock_irqrestore(&il->lock, flags);

        /* Alloc and init all Tx queues, including the command queue (#4) */
        for (txq_id = 0; txq_id < il->hw_params.max_txq_num; txq_id++)
                il_tx_queue_reset(il, txq_id);
}

void
il4965_txq_ctx_unmap(struct il_priv *il)
{
        int txq_id;

        if (!il->txq)
                return;

        /* Unmap DMA from host system and free skb's */
        for (txq_id = 0; txq_id < il->hw_params.max_txq_num; txq_id++)
                if (txq_id == il->cmd_queue)
                        il_cmd_queue_unmap(il);
                else
                        il_tx_queue_unmap(il, txq_id);
}

/**
 * il4965_txq_ctx_stop - Stop all Tx DMA channels
 */
void
il4965_txq_ctx_stop(struct il_priv *il)
{
        int ch, ret;

        _il_wr_prph(il, IL49_SCD_TXFACT, 0);

        /* Stop each Tx DMA channel, and wait for it to be idle */
        for (ch = 0; ch < il->hw_params.dma_chnl_num; ch++) {
                _il_wr(il, FH49_TCSR_CHNL_TX_CONFIG_REG(ch), 0x0);
                ret =
                    _il_poll_bit(il, FH49_TSSR_TX_STATUS_REG,
                                 FH49_TSSR_TX_STATUS_REG_MSK_CHNL_IDLE(ch),
                                 FH49_TSSR_TX_STATUS_REG_MSK_CHNL_IDLE(ch),
                                 1000);
                if (ret < 0)
                        IL_ERR("Timeout stopping DMA channel %d [0x%08x]",
                               ch, _il_rd(il, FH49_TSSR_TX_STATUS_REG));
        }
}

/*
 * Find first available (lowest unused) Tx Queue, mark it "active".
 * Called only when finding queue for aggregation.
 * Should never return anything < 7, because they should already
 * be in use as EDCA AC (0-3), Command (4), reserved (5, 6)
 */
static int
il4965_txq_ctx_activate_free(struct il_priv *il)
{
        int txq_id;

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

/**
 * il4965_tx_queue_stop_scheduler - Stop queue, but keep configuration
 */
static void
il4965_tx_queue_stop_scheduler(struct il_priv *il, u16 txq_id)
{
        /* Simply stop the queue, but don't change any configuration;
         * the SCD_ACT_EN bit is the write-enable mask for the ACTIVE bit. */
        il_wr_prph(il, IL49_SCD_QUEUE_STATUS_BITS(txq_id),
                   (0 << IL49_SCD_QUEUE_STTS_REG_POS_ACTIVE) |
                   (1 << IL49_SCD_QUEUE_STTS_REG_POS_SCD_ACT_EN));
}

/**
 * il4965_tx_queue_set_q2ratid - Map unique receiver/tid combination to a queue
 */
static int
il4965_tx_queue_set_q2ratid(struct il_priv *il, u16 ra_tid, u16 txq_id)
{
        u32 tbl_dw_addr;
        u32 tbl_dw;
        u16 scd_q2ratid;

        scd_q2ratid = ra_tid & IL_SCD_QUEUE_RA_TID_MAP_RATID_MSK;

        tbl_dw_addr =
            il->scd_base_addr + IL49_SCD_TRANSLATE_TBL_OFFSET_QUEUE(txq_id);

        tbl_dw = il_read_targ_mem(il, tbl_dw_addr);

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

        il_write_targ_mem(il, tbl_dw_addr, tbl_dw);

        return 0;
}

/**
 * il4965_tx_queue_agg_enable - Set up & enable aggregation for selected queue
 *
 * NOTE:  txq_id must be greater than IL49_FIRST_AMPDU_QUEUE,
 *        i.e. it must be one of the higher queues used for aggregation
 */
static int
il4965_txq_agg_enable(struct il_priv *il, int txq_id, int tx_fifo, int sta_id,
                      int tid, u16 ssn_idx)
{
        unsigned long flags;
        u16 ra_tid;
        int ret;

        if ((IL49_FIRST_AMPDU_QUEUE > txq_id) ||
            (IL49_FIRST_AMPDU_QUEUE +
             il->cfg->num_of_ampdu_queues <= txq_id)) {
                IL_WARN("queue number out of range: %d, must be %d to %d\n",
                        txq_id, IL49_FIRST_AMPDU_QUEUE,
                        IL49_FIRST_AMPDU_QUEUE +
                        il->cfg->num_of_ampdu_queues - 1);
                return -EINVAL;
        }

        ra_tid = BUILD_RAxTID(sta_id, tid);

        /* Modify device's station table to Tx this TID */
        ret = il4965_sta_tx_modify_enable_tid(il, sta_id, tid);
        if (ret)
                return ret;

        spin_lock_irqsave(&il->lock, flags);

        /* Stop this Tx queue before configuring it */
        il4965_tx_queue_stop_scheduler(il, txq_id);

        /* Map receiver-address / traffic-ID to this queue */
        il4965_tx_queue_set_q2ratid(il, ra_tid, txq_id);

        /* Set this queue as a chain-building queue */
        il_set_bits_prph(il, IL49_SCD_QUEUECHAIN_SEL, (1 << txq_id));

        /* Place first TFD at idx corresponding to start sequence number.
         * Assumes that ssn_idx is valid (!= 0xFFF) */
        il->txq[txq_id].q.read_ptr = (ssn_idx & 0xff);
        il->txq[txq_id].q.write_ptr = (ssn_idx & 0xff);
        il4965_set_wr_ptrs(il, txq_id, ssn_idx);

        /* Set up Tx win size and frame limit for this queue */
        il_write_targ_mem(il,
                          il->scd_base_addr +
                          IL49_SCD_CONTEXT_QUEUE_OFFSET(txq_id),
                          (SCD_WIN_SIZE << IL49_SCD_QUEUE_CTX_REG1_WIN_SIZE_POS)
                          & IL49_SCD_QUEUE_CTX_REG1_WIN_SIZE_MSK);

        il_write_targ_mem(il,
                          il->scd_base_addr +
                          IL49_SCD_CONTEXT_QUEUE_OFFSET(txq_id) + sizeof(u32),
                          (SCD_FRAME_LIMIT <<
                           IL49_SCD_QUEUE_CTX_REG2_FRAME_LIMIT_POS) &
                          IL49_SCD_QUEUE_CTX_REG2_FRAME_LIMIT_MSK);

        il_set_bits_prph(il, IL49_SCD_INTERRUPT_MASK, (1 << txq_id));

        /* Set up Status area in SRAM, map to Tx DMA/FIFO, activate the queue */
        il4965_tx_queue_set_status(il, &il->txq[txq_id], tx_fifo, 1);

        spin_unlock_irqrestore(&il->lock, flags);

        return 0;
}

int
il4965_tx_agg_start(struct il_priv *il, struct ieee80211_vif *vif,
                    struct ieee80211_sta *sta, u16 tid, u16 * ssn)
{
        int sta_id;
        int tx_fifo;
        int txq_id;
        int ret;
        unsigned long flags;
        struct il_tid_data *tid_data;

        /* FIXME: warning if tx fifo not found ? */
        tx_fifo = il4965_get_fifo_from_tid(tid);
        if (unlikely(tx_fifo < 0))
                return tx_fifo;

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

        sta_id = il_sta_id(sta);
        if (sta_id == IL_INVALID_STATION) {
                IL_ERR("Start AGG on invalid station\n");
                return -ENXIO;
        }
        if (unlikely(tid >= MAX_TID_COUNT))
                return -EINVAL;

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

        txq_id = il4965_txq_ctx_activate_free(il);
        if (txq_id == -1) {
                IL_ERR("No free aggregation queue available\n");
                return -ENXIO;
        }

        spin_lock_irqsave(&il->sta_lock, flags);
        tid_data = &il->stations[sta_id].tid[tid];
        *ssn = SEQ_TO_SN(tid_data->seq_number);
        tid_data->agg.txq_id = txq_id;
        il_set_swq_id(&il->txq[txq_id], il4965_get_ac_from_tid(tid), txq_id);
        spin_unlock_irqrestore(&il->sta_lock, flags);

        ret = il4965_txq_agg_enable(il, txq_id, tx_fifo, sta_id, tid, *ssn);
        if (ret)
                return ret;

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

/**
 * txq_id must be greater than IL49_FIRST_AMPDU_QUEUE
 * il->lock must be held by the caller
 */
static int
il4965_txq_agg_disable(struct il_priv *il, u16 txq_id, u16 ssn_idx, u8 tx_fifo)
{
        if ((IL49_FIRST_AMPDU_QUEUE > txq_id) ||
            (IL49_FIRST_AMPDU_QUEUE +
             il->cfg->num_of_ampdu_queues <= txq_id)) {
                IL_WARN("queue number out of range: %d, must be %d to %d\n",
                        txq_id, IL49_FIRST_AMPDU_QUEUE,
                        IL49_FIRST_AMPDU_QUEUE +
                        il->cfg->num_of_ampdu_queues - 1);
                return -EINVAL;
        }

        il4965_tx_queue_stop_scheduler(il, txq_id);

        il_clear_bits_prph(il, IL49_SCD_QUEUECHAIN_SEL, (1 << txq_id));

        il->txq[txq_id].q.read_ptr = (ssn_idx & 0xff);
        il->txq[txq_id].q.write_ptr = (ssn_idx & 0xff);
        /* supposes that ssn_idx is valid (!= 0xFFF) */
        il4965_set_wr_ptrs(il, txq_id, ssn_idx);

        il_clear_bits_prph(il, IL49_SCD_INTERRUPT_MASK, (1 << txq_id));
        il_txq_ctx_deactivate(il, txq_id);
        il4965_tx_queue_set_status(il, &il->txq[txq_id], tx_fifo, 0);

        return 0;
}

int
il4965_tx_agg_stop(struct il_priv *il, struct ieee80211_vif *vif,
                   struct ieee80211_sta *sta, u16 tid)
{
        int tx_fifo_id, txq_id, sta_id, ssn;
        struct il_tid_data *tid_data;
        int write_ptr, read_ptr;
        unsigned long flags;

        /* FIXME: warning if tx_fifo_id not found ? */
        tx_fifo_id = il4965_get_fifo_from_tid(tid);
        if (unlikely(tx_fifo_id < 0))
                return tx_fifo_id;

        sta_id = il_sta_id(sta);

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

        spin_lock_irqsave(&il->sta_lock, flags);

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

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

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

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

        D_HT("HW queue is empty\n");
turn_off:
        il->stations[sta_id].tid[tid].agg.state = IL_AGG_OFF;

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

        /*
         * the only reason this call can fail is queue number out of range,
         * which can happen if uCode is reloaded and all the station
         * information are lost. if it is outside the range, there is no need
         * to deactivate the uCode queue, just return "success" to allow
         *  mac80211 to clean up it own data.
         */
        il4965_txq_agg_disable(il, txq_id, ssn, tx_fifo_id);
        spin_unlock_irqrestore(&il->lock, flags);

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

        return 0;
}

int
il4965_txq_check_empty(struct il_priv *il, int sta_id, u8 tid, int txq_id)
{
        struct il_queue *q = &il->txq[txq_id].q;
        u8 *addr = il->stations[sta_id].sta.sta.addr;
        struct il_tid_data *tid_data = &il->stations[sta_id].tid[tid];

        lockdep_assert_held(&il->sta_lock);

        switch (il->stations[sta_id].tid[tid].agg.state) {
        case IL_EMPTYING_HW_QUEUE_DELBA:
                /* We are reclaiming the last packet of the */
                /* aggregated HW queue */
                if (txq_id == tid_data->agg.txq_id &&
                    q->read_ptr == q->write_ptr) {
                        u16 ssn = SEQ_TO_SN(tid_data->seq_number);
                        int tx_fifo = il4965_get_fifo_from_tid(tid);
                        D_HT("HW queue empty: continue DELBA flow\n");
                        il4965_txq_agg_disable(il, txq_id, ssn, tx_fifo);
                        tid_data->agg.state = IL_AGG_OFF;
                        ieee80211_stop_tx_ba_cb_irqsafe(il->vif, addr, tid);
                }
                break;
        case IL_EMPTYING_HW_QUEUE_ADDBA:
                /* We are reclaiming the last packet of the queue */
                if (tid_data->tfds_in_queue == 0) {
                        D_HT("HW queue empty: continue ADDBA flow\n");
                        tid_data->agg.state = IL_AGG_ON;
                        ieee80211_start_tx_ba_cb_irqsafe(il->vif, addr, tid);
                }
                break;
        }

        return 0;
}

static void
il4965_non_agg_tx_status(struct il_priv *il, const u8 *addr1)
{
        struct ieee80211_sta *sta;
        struct il_station_priv *sta_priv;

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

static void
il4965_tx_status(struct il_priv *il, struct sk_buff *skb, bool is_agg)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;

        if (!is_agg)
                il4965_non_agg_tx_status(il, hdr->addr1);

        ieee80211_tx_status_irqsafe(il->hw, skb);
}

int
il4965_tx_queue_reclaim(struct il_priv *il, int txq_id, int idx)
{
        struct il_tx_queue *txq = &il->txq[txq_id];
        struct il_queue *q = &txq->q;
        int nfreed = 0;
        struct ieee80211_hdr *hdr;
        struct sk_buff *skb;

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

        for (idx = il_queue_inc_wrap(idx, q->n_bd); q->read_ptr != idx;
             q->read_ptr = il_queue_inc_wrap(q->read_ptr, q->n_bd)) {

                skb = txq->skbs[txq->q.read_ptr];

                if (WARN_ON_ONCE(skb == NULL))
                        continue;

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

                il4965_tx_status(il, skb, txq_id >= IL4965_FIRST_AMPDU_QUEUE);

                txq->skbs[txq->q.read_ptr] = NULL;
                il->ops->txq_free_tfd(il, txq);
        }
        return nfreed;
}

/**
 * il4965_tx_status_reply_compressed_ba - Update tx status from block-ack
 *
 * Go through block-ack's bitmap of ACK'd frames, update driver's record of
 * ACK vs. not.  This gets sent to mac80211, then to rate scaling algo.
 */
static int
il4965_tx_status_reply_compressed_ba(struct il_priv *il, struct il_ht_agg *agg,
                                     struct il_compressed_ba_resp *ba_resp)
{
        int i, sh, ack;
        u16 seq_ctl = le16_to_cpu(ba_resp->seq_ctl);
        u16 scd_flow = le16_to_cpu(ba_resp->scd_flow);
        int successes = 0;
        struct ieee80211_tx_info *info;
        u64 bitmap, sent_bitmap;

        if (unlikely(!agg->wait_for_ba)) {
                if (unlikely(ba_resp->bitmap))
                        IL_ERR("Received BA when not expected\n");
                return -EINVAL;
        }

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

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

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

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

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

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

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

        info = IEEE80211_SKB_CB(il->txq[scd_flow].skbs[agg->start_idx]);
        memset(&info->status, 0, sizeof(info->status));
        info->flags |= IEEE80211_TX_STAT_ACK;
        info->flags |= IEEE80211_TX_STAT_AMPDU;
        info->status.ampdu_ack_len = successes;
        info->status.ampdu_len = agg->frame_count;
        il4965_hwrate_to_tx_control(il, agg->rate_n_flags, info);

        return 0;
}

static inline bool
il4965_is_tx_success(u32 status)
{
        status &= TX_STATUS_MSK;
        return (status == TX_STATUS_SUCCESS || status == TX_STATUS_DIRECT_DONE);
}

static u8
il4965_find_station(struct il_priv *il, const u8 *addr)
{
        int i;
        int start = 0;
        int ret = IL_INVALID_STATION;
        unsigned long flags;

        if (il->iw_mode == NL80211_IFTYPE_ADHOC)
                start = IL_STA_ID;

        if (is_broadcast_ether_addr(addr))
                return il->hw_params.bcast_id;

        spin_lock_irqsave(&il->sta_lock, flags);
        for (i = start; i < il->hw_params.max_stations; i++)
                if (il->stations[i].used &&
                    ether_addr_equal(il->stations[i].sta.sta.addr, addr)) {
                        ret = i;
                        goto out;
                }

        D_ASSOC("can not find STA %pM total %d\n", addr, il->num_stations);

out:
        /*
         * It may be possible that more commands interacting with stations
         * arrive before we completed processing the adding of
         * station
         */
        if (ret != IL_INVALID_STATION &&
            (!(il->stations[ret].used & IL_STA_UCODE_ACTIVE) ||
             ((il->stations[ret].used & IL_STA_UCODE_ACTIVE) &&
              (il->stations[ret].used & IL_STA_UCODE_INPROGRESS)))) {
                IL_ERR("Requested station info for sta %d before ready.\n",
                       ret);
                ret = IL_INVALID_STATION;
        }
        spin_unlock_irqrestore(&il->sta_lock, flags);
        return ret;
}

static int
il4965_get_ra_sta_id(struct il_priv *il, struct ieee80211_hdr *hdr)
{
        if (il->iw_mode == NL80211_IFTYPE_STATION)
                return IL_AP_ID;
        else {
                u8 *da = ieee80211_get_DA(hdr);

                return il4965_find_station(il, da);
        }
}

static inline u32
il4965_get_scd_ssn(struct il4965_tx_resp *tx_resp)
{
        return le32_to_cpup(&tx_resp->u.status + tx_resp->frame_count) & MAX_SN;
}

static inline u32
il4965_tx_status_to_mac80211(u32 status)
{
        status &= TX_STATUS_MSK;

        switch (status) {
        case TX_STATUS_SUCCESS:
        case TX_STATUS_DIRECT_DONE:
                return IEEE80211_TX_STAT_ACK;
        case TX_STATUS_FAIL_DEST_PS:
                return IEEE80211_TX_STAT_TX_FILTERED;
        default:
                return 0;
        }
}

/**
 * il4965_tx_status_reply_tx - Handle Tx response for frames in aggregation queue
 */
static int
il4965_tx_status_reply_tx(struct il_priv *il, struct il_ht_agg *agg,
                          struct il4965_tx_resp *tx_resp, int txq_id,
                          u16 start_idx)
{
        u16 status;
        struct agg_tx_status *frame_status = tx_resp->u.agg_status;
        struct ieee80211_tx_info *info = NULL;
        struct ieee80211_hdr *hdr = NULL;
        u32 rate_n_flags = le32_to_cpu(tx_resp->rate_n_flags);
        int i, sh, idx;
        u16 seq;
        if (agg->wait_for_ba)
                D_TX_REPLY("got tx response w/o block-ack\n");

        agg->frame_count = tx_resp->frame_count;
        agg->start_idx = start_idx;
        agg->rate_n_flags = rate_n_flags;
        agg->bitmap = 0;

        /* num frames attempted by Tx command */
        if (agg->frame_count == 1) {
                /* Only one frame was attempted; no block-ack will arrive */
                status = le16_to_cpu(frame_status[0].status);
                idx = start_idx;

                D_TX_REPLY("FrameCnt = %d, StartIdx=%d idx=%d\n",
                           agg->frame_count, agg->start_idx, idx);

                info = IEEE80211_SKB_CB(il->txq[txq_id].skbs[idx]);
                info->status.rates[0].count = tx_resp->failure_frame + 1;
                info->flags &= ~IEEE80211_TX_CTL_AMPDU;
                info->flags |= il4965_tx_status_to_mac80211(status);
                il4965_hwrate_to_tx_control(il, rate_n_flags, info);

                D_TX_REPLY("1 Frame 0x%x failure :%d\n", status & 0xff,
                           tx_resp->failure_frame);
                D_TX_REPLY("Rate Info rate_n_flags=%x\n", rate_n_flags);

                agg->wait_for_ba = 0;
        } else {
                /* Two or more frames were attempted; expect block-ack */
                u64 bitmap = 0;
                int start = agg->start_idx;
                struct sk_buff *skb;

                /* Construct bit-map of pending frames within Tx win */
                for (i = 0; i < agg->frame_count; i++) {
                        u16 sc;
                        status = le16_to_cpu(frame_status[i].status);
                        seq = le16_to_cpu(frame_status[i].sequence);
                        idx = SEQ_TO_IDX(seq);
                        txq_id = SEQ_TO_QUEUE(seq);

                        if (status &
                            (AGG_TX_STATE_FEW_BYTES_MSK |
                             AGG_TX_STATE_ABORT_MSK))
                                continue;

                        D_TX_REPLY("FrameCnt = %d, txq_id=%d idx=%d\n",
                                   agg->frame_count, txq_id, idx);

                        skb = il->txq[txq_id].skbs[idx];
                        if (WARN_ON_ONCE(skb == NULL))
                                return -1;
                        hdr = (struct ieee80211_hdr *) skb->data;

                        sc = le16_to_cpu(hdr->seq_ctrl);
                        if (idx != (SEQ_TO_SN(sc) & 0xff)) {
                                IL_ERR("BUG_ON idx doesn't match seq control"
                                       " idx=%d, seq_idx=%d, seq=%d\n", idx,
                                       SEQ_TO_SN(sc), hdr->seq_ctrl);
                                return -1;
                        }

                        D_TX_REPLY("AGG Frame i=%d idx %d seq=%d\n", i, idx,
                                   SEQ_TO_SN(sc));

                        sh = idx - start;
                        if (sh > 64) {
                                sh = (start - idx) + 0xff;
                                bitmap = bitmap << sh;
                                sh = 0;
                                start = idx;
                        } else if (sh < -64)
                                sh = 0xff - (start - idx);
                        else if (sh < 0) {
                                sh = start - idx;
                                start = idx;
                                bitmap = bitmap << sh;
                                sh = 0;
                        }
                        bitmap |= 1ULL << sh;
                        D_TX_REPLY("start=%d bitmap=0x%llx\n", start,
                                   (unsigned long long)bitmap);
                }

                agg->bitmap = bitmap;
                agg->start_idx = start;
                D_TX_REPLY("Frames %d start_idx=%d bitmap=0x%llx\n",
                           agg->frame_count, agg->start_idx,
                           (unsigned long long)agg->bitmap);

                if (bitmap)
                        agg->wait_for_ba = 1;
        }
        return 0;
}

/**
 * il4965_hdl_tx - Handle standard (non-aggregation) Tx response
 */
static void
il4965_hdl_tx(struct il_priv *il, struct il_rx_buf *rxb)
{
        struct il_rx_pkt *pkt = rxb_addr(rxb);
        u16 sequence = le16_to_cpu(pkt->hdr.sequence);
        int txq_id = SEQ_TO_QUEUE(sequence);
        int idx = SEQ_TO_IDX(sequence);
        struct il_tx_queue *txq = &il->txq[txq_id];
        struct sk_buff *skb;
        struct ieee80211_hdr *hdr;
        struct ieee80211_tx_info *info;
        struct il4965_tx_resp *tx_resp = (void *)&pkt->u.raw[0];
        u32 status = le32_to_cpu(tx_resp->u.status);
        int uninitialized_var(tid);
        int sta_id;
        int freed;
        u8 *qc = NULL;
        unsigned long flags;

        if (idx >= txq->q.n_bd || il_queue_used(&txq->q, idx) == 0) {
                IL_ERR("Read idx for DMA queue txq_id (%d) idx %d "
                       "is out of range [0-%d] %d %d\n", txq_id, idx,
                       txq->q.n_bd, txq->q.write_ptr, txq->q.read_ptr);
                return;
        }

        txq->time_stamp = jiffies;

        skb = txq->skbs[txq->q.read_ptr];
        info = IEEE80211_SKB_CB(skb);
        memset(&info->status, 0, sizeof(info->status));

        hdr = (struct ieee80211_hdr *) skb->data;
        if (ieee80211_is_data_qos(hdr->frame_control)) {
                qc = ieee80211_get_qos_ctl(hdr);
                tid = qc[0] & 0xf;
        }

        sta_id = il4965_get_ra_sta_id(il, hdr);
        if (txq->sched_retry && unlikely(sta_id == IL_INVALID_STATION)) {
                IL_ERR("Station not known\n");
                return;
        }

        spin_lock_irqsave(&il->sta_lock, flags);
        if (txq->sched_retry) {
                const u32 scd_ssn = il4965_get_scd_ssn(tx_resp);
                struct il_ht_agg *agg = NULL;
                WARN_ON(!qc);

                agg = &il->stations[sta_id].tid[tid].agg;

                il4965_tx_status_reply_tx(il, agg, tx_resp, txq_id, idx);

                /* check if BAR is needed */
                if (tx_resp->frame_count == 1 &&
                    !il4965_is_tx_success(status))
                        info->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;

                if (txq->q.read_ptr != (scd_ssn & 0xff)) {
                        idx = il_queue_dec_wrap(scd_ssn & 0xff, txq->q.n_bd);
                        D_TX_REPLY("Retry scheduler reclaim scd_ssn "
                                   "%d idx %d\n", scd_ssn, idx);
                        freed = il4965_tx_queue_reclaim(il, txq_id, idx);
                        if (qc)
                                il4965_free_tfds_in_queue(il, sta_id, tid,
                                                          freed);

                        if (il->mac80211_registered &&
                            il_queue_space(&txq->q) > txq->q.low_mark &&
                            agg->state != IL_EMPTYING_HW_QUEUE_DELBA)
                                il_wake_queue(il, txq);
                }
        } else {
                info->status.rates[0].count = tx_resp->failure_frame + 1;
                info->flags |= il4965_tx_status_to_mac80211(status);
                il4965_hwrate_to_tx_control(il,
                                            le32_to_cpu(tx_resp->rate_n_flags),
                                            info);

                D_TX_REPLY("TXQ %d status %s (0x%08x) "
                           "rate_n_flags 0x%x retries %d\n", txq_id,
                           il4965_get_tx_fail_reason(status), status,
                           le32_to_cpu(tx_resp->rate_n_flags),
                           tx_resp->failure_frame);

                freed = il4965_tx_queue_reclaim(il, txq_id, idx);
                if (qc && likely(sta_id != IL_INVALID_STATION))
                        il4965_free_tfds_in_queue(il, sta_id, tid, freed);
                else if (sta_id == IL_INVALID_STATION)
                        D_TX_REPLY("Station not known\n");

                if (il->mac80211_registered &&
                    il_queue_space(&txq->q) > txq->q.low_mark)
                        il_wake_queue(il, txq);
        }
        if (qc && likely(sta_id != IL_INVALID_STATION))
                il4965_txq_check_empty(il, sta_id, tid, txq_id);

        il4965_check_abort_status(il, tx_resp->frame_count, status);

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

/**
 * translate ucode response to mac80211 tx status control values
 */
void
il4965_hwrate_to_tx_control(struct il_priv *il, u32 rate_n_flags,
                            struct ieee80211_tx_info *info)
{
        struct ieee80211_tx_rate *r = &info->status.rates[0];

        info->status.antenna =
            ((rate_n_flags & RATE_MCS_ANT_ABC_MSK) >> RATE_MCS_ANT_POS);
        if (rate_n_flags & RATE_MCS_HT_MSK)
                r->flags |= IEEE80211_TX_RC_MCS;
        if (rate_n_flags & RATE_MCS_GF_MSK)
                r->flags |= IEEE80211_TX_RC_GREEN_FIELD;
        if (rate_n_flags & RATE_MCS_HT40_MSK)
                r->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
        if (rate_n_flags & RATE_MCS_DUP_MSK)
                r->flags |= IEEE80211_TX_RC_DUP_DATA;
        if (rate_n_flags & RATE_MCS_SGI_MSK)
                r->flags |= IEEE80211_TX_RC_SHORT_GI;
        r->idx = il4965_hwrate_to_mac80211_idx(rate_n_flags, info->band);
}

/**
 * il4965_hdl_compressed_ba - Handler for N_COMPRESSED_BA
 *
 * Handles block-acknowledge notification from device, which reports success
 * of frames sent via aggregation.
 */
void
il4965_hdl_compressed_ba(struct il_priv *il, struct il_rx_buf *rxb)
{
        struct il_rx_pkt *pkt = rxb_addr(rxb);
        struct il_compressed_ba_resp *ba_resp = &pkt->u.compressed_ba;
        struct il_tx_queue *txq = NULL;
        struct il_ht_agg *agg;
        int idx;
        int sta_id;
        int tid;
        unsigned long flags;

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

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

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

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

        /* Find idx just before block-ack win */
        idx = il_queue_dec_wrap(ba_resp_scd_ssn & 0xff, txq->q.n_bd);

        spin_lock_irqsave(&il->sta_lock, flags);

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

        /* Update driver's record of ACK vs. not for each frame in win */
        il4965_tx_status_reply_compressed_ba(il, agg, ba_resp);

        /* Release all TFDs before the SSN, i.e. all TFDs in front of
         * block-ack win (we assume that they've been successfully
         * transmitted ... if not, it's too late anyway). */
        if (txq->q.read_ptr != (ba_resp_scd_ssn & 0xff)) {
                /* calculate mac80211 ampdu sw queue to wake */
                int freed = il4965_tx_queue_reclaim(il, scd_flow, idx);
                il4965_free_tfds_in_queue(il, sta_id, tid, freed);

                if (il_queue_space(&txq->q) > txq->q.low_mark &&
                    il->mac80211_registered &&
                    agg->state != IL_EMPTYING_HW_QUEUE_DELBA)
                        il_wake_queue(il, txq);

                il4965_txq_check_empty(il, sta_id, tid, scd_flow);
        }

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

#ifdef CONFIG_IWLEGACY_DEBUG
const char *
il4965_get_tx_fail_reason(u32 status)
{
#define TX_STATUS_FAIL(x) case TX_STATUS_FAIL_ ## x: return #x
#define TX_STATUS_POSTPONE(x) case TX_STATUS_POSTPONE_ ## x: return #x

        switch (status & TX_STATUS_MSK) {
        case TX_STATUS_SUCCESS:
                return "SUCCESS";
                TX_STATUS_POSTPONE(DELAY);
                TX_STATUS_POSTPONE(FEW_BYTES);
                TX_STATUS_POSTPONE(QUIET_PERIOD);
                TX_STATUS_POSTPONE(CALC_TTAK);
                TX_STATUS_FAIL(INTERNAL_CROSSED_RETRY);
                TX_STATUS_FAIL(SHORT_LIMIT);
                TX_STATUS_FAIL(LONG_LIMIT);
                TX_STATUS_FAIL(FIFO_UNDERRUN);
                TX_STATUS_FAIL(DRAIN_FLOW);
                TX_STATUS_FAIL(RFKILL_FLUSH);
                TX_STATUS_FAIL(LIFE_EXPIRE);
                TX_STATUS_FAIL(DEST_PS);
                TX_STATUS_FAIL(HOST_ABORTED);
                TX_STATUS_FAIL(BT_RETRY);
                TX_STATUS_FAIL(STA_INVALID);
                TX_STATUS_FAIL(FRAG_DROPPED);