rt2x00dev.c

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/*
    Copyright (C) 2010 Willow Garage <http://www.willowgarage.com>
    Copyright (C) 2004 - 2010 Ivo van Doorn <[email protected]>
    <http://rt2x00.serialmonkey.com>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    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.,
    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
    Module: rt2x00lib
    Abstract: rt2x00 generic device routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/log2.h>

#include "rt2x00.h"
#include "rt2x00lib.h"

/*
 * Utility functions.
 */
u32 rt2x00lib_get_bssidx(struct rt2x00_dev *rt2x00dev,
             struct ieee80211_vif *vif)
{
    /*
     * When in STA mode, bssidx is always 0 otherwise local_address[5]
     * contains the bss number, see BSS_ID_MASK comments for details.
     */
    if (rt2x00dev->intf_sta_count)
        return 0;
    return vif->addr[5] & (rt2x00dev->ops->max_ap_intf - 1);
}
EXPORT_SYMBOL_GPL(rt2x00lib_get_bssidx);

/*
 * Radio control handlers.
 */
int rt2x00lib_enable_radio(struct rt2x00_dev *rt2x00dev)
{
    int status;

    /*
     * Don't enable the radio twice.
     * And check if the hardware button has been disabled.
     */
    if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
        return 0;

    /*
     * Initialize all data queues.
     */
    rt2x00queue_init_queues(rt2x00dev);

    /*
     * Enable radio.
     */
    status =
        rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_ON);
    if (status)
        return status;

    rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_IRQ_ON);

    rt2x00leds_led_radio(rt2x00dev, true);
    rt2x00led_led_activity(rt2x00dev, true);

    set_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags);

    /*
     * Enable queues.
     */
    rt2x00queue_start_queues(rt2x00dev);
    rt2x00link_start_tuner(rt2x00dev);
    rt2x00link_start_agc(rt2x00dev);
    if (test_bit(CAPABILITY_VCO_RECALIBRATION, &rt2x00dev->cap_flags))
        rt2x00link_start_vcocal(rt2x00dev);

    /*
     * Start watchdog monitoring.
     */
    rt2x00link_start_watchdog(rt2x00dev);

    return 0;
}

void rt2x00lib_disable_radio(struct rt2x00_dev *rt2x00dev)
{
    if (!test_and_clear_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
        return;

    /*
     * Stop watchdog monitoring.
     */
    rt2x00link_stop_watchdog(rt2x00dev);

    /*
     * Stop all queues
     */
    rt2x00link_stop_agc(rt2x00dev);
    if (test_bit(CAPABILITY_VCO_RECALIBRATION, &rt2x00dev->cap_flags))
        rt2x00link_stop_vcocal(rt2x00dev);
    rt2x00link_stop_tuner(rt2x00dev);
    rt2x00queue_stop_queues(rt2x00dev);
    rt2x00queue_flush_queues(rt2x00dev, true);

    /*
     * Disable radio.
     */
    rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_OFF);
    rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_IRQ_OFF);
    rt2x00led_led_activity(rt2x00dev, false);
    rt2x00leds_led_radio(rt2x00dev, false);
}

static void rt2x00lib_intf_scheduled_iter(void *data, u8 *mac,
                      struct ieee80211_vif *vif)
{
    struct rt2x00_dev *rt2x00dev = data;
    struct rt2x00_intf *intf = vif_to_intf(vif);

    /*
     * It is possible the radio was disabled while the work had been
     * scheduled. If that happens we should return here immediately,
     * note that in the spinlock protected area above the delayed_flags
     * have been cleared correctly.
     */
    if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
        return;

    if (test_and_clear_bit(DELAYED_UPDATE_BEACON, &intf->delayed_flags))
        rt2x00queue_update_beacon(rt2x00dev, vif);
}

static void rt2x00lib_intf_scheduled(struct work_struct *work)
{
    struct rt2x00_dev *rt2x00dev =
        container_of(work, struct rt2x00_dev, intf_work);

    /*
     * Iterate over each interface and perform the
     * requested configurations.
     */
    ieee80211_iterate_active_interfaces(rt2x00dev->hw,
                        rt2x00lib_intf_scheduled_iter,
                        rt2x00dev);
}

static void rt2x00lib_autowakeup(struct work_struct *work)
{
    struct rt2x00_dev *rt2x00dev =
        container_of(work, struct rt2x00_dev, autowakeup_work.work);

    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
        return;

    if (rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_AWAKE))
        ERROR(rt2x00dev, "Device failed to wakeup.\n");
    clear_bit(CONFIG_POWERSAVING, &rt2x00dev->flags);
}

/*
 * Interrupt context handlers.
 */
static void rt2x00lib_bc_buffer_iter(void *data, u8 *mac,
                     struct ieee80211_vif *vif)
{
    struct rt2x00_dev *rt2x00dev = data;
    struct sk_buff *skb;

    /*
     * Only AP mode interfaces do broad- and multicast buffering
     */
    if (vif->type != NL80211_IFTYPE_AP)
        return;

    /*
     * Send out buffered broad- and multicast frames
     */
    skb = ieee80211_get_buffered_bc(rt2x00dev->hw, vif);
    while (skb) {
        rt2x00mac_tx(rt2x00dev->hw, NULL, skb);
        skb = ieee80211_get_buffered_bc(rt2x00dev->hw, vif);
    }
}

static void rt2x00lib_beaconupdate_iter(void *data, u8 *mac,
                    struct ieee80211_vif *vif)
{
    struct rt2x00_dev *rt2x00dev = data;

    if (vif->type != NL80211_IFTYPE_AP &&
        vif->type != NL80211_IFTYPE_ADHOC &&
        vif->type != NL80211_IFTYPE_MESH_POINT &&
        vif->type != NL80211_IFTYPE_WDS)
        return;

    /*
     * Update the beacon without locking. This is safe on PCI devices
     * as they only update the beacon periodically here. This should
     * never be called for USB devices.
     */
    WARN_ON(rt2x00_is_usb(rt2x00dev));
    rt2x00queue_update_beacon_locked(rt2x00dev, vif);
}

void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
{
    if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
        return;

    /* send buffered bc/mc frames out for every bssid */
    ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
                           rt2x00lib_bc_buffer_iter,
                           rt2x00dev);
    /*
     * Devices with pre tbtt interrupt don't need to update the beacon
     * here as they will fetch the next beacon directly prior to
     * transmission.
     */
    if (test_bit(CAPABILITY_PRE_TBTT_INTERRUPT, &rt2x00dev->cap_flags))
        return;

    /* fetch next beacon */
    ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
                           rt2x00lib_beaconupdate_iter,
                           rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00lib_beacondone);

void rt2x00lib_pretbtt(struct rt2x00_dev *rt2x00dev)
{
    if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
        return;

    /* fetch next beacon */
    ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
                           rt2x00lib_beaconupdate_iter,
                           rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00lib_pretbtt);

void rt2x00lib_dmastart(struct queue_entry *entry)
{
    set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
    rt2x00queue_index_inc(entry, Q_INDEX);
}
EXPORT_SYMBOL_GPL(rt2x00lib_dmastart);

void rt2x00lib_dmadone(struct queue_entry *entry)
{
    set_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags);
    clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
    rt2x00queue_index_inc(entry, Q_INDEX_DMA_DONE);
}
EXPORT_SYMBOL_GPL(rt2x00lib_dmadone);

void rt2x00lib_txdone(struct queue_entry *entry,
              struct txdone_entry_desc *txdesc)
{
    struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
    struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
    struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
    unsigned int header_length, i;
    u8 rate_idx, rate_flags, retry_rates;
    u8 skbdesc_flags = skbdesc->flags;
    bool success;

    /*
     * Unmap the skb.
     */
    rt2x00queue_unmap_skb(entry);

    /*
     * Remove the extra tx headroom from the skb.
     */
    skb_pull(entry->skb, rt2x00dev->ops->extra_tx_headroom);

    /*
     * Signal that the TX descriptor is no longer in the skb.
     */
    skbdesc->flags &= ~SKBDESC_DESC_IN_SKB;

    /*
     * Determine the length of 802.11 header.
     */
    header_length = ieee80211_get_hdrlen_from_skb(entry->skb);

    /*
     * Remove L2 padding which was added during
     */
    if (test_bit(REQUIRE_L2PAD, &rt2x00dev->cap_flags))
        rt2x00queue_remove_l2pad(entry->skb, header_length);

    /*
     * If the IV/EIV data was stripped from the frame before it was
     * passed to the hardware, we should now reinsert it again because
     * mac80211 will expect the same data to be present it the
     * frame as it was passed to us.
     */
    if (test_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags))
        rt2x00crypto_tx_insert_iv(entry->skb, header_length);

    /*
     * Send frame to debugfs immediately, after this call is completed
     * we are going to overwrite the skb->cb array.
     */
    rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TXDONE, entry->skb);

    /*
     * Determine if the frame has been successfully transmitted.
     */
    success =
        test_bit(TXDONE_SUCCESS, &txdesc->flags) ||
        test_bit(TXDONE_UNKNOWN, &txdesc->flags);

    /*
     * Update TX statistics.
     */
    rt2x00dev->link.qual.tx_success += success;
    rt2x00dev->link.qual.tx_failed += !success;

    rate_idx = skbdesc->tx_rate_idx;
    rate_flags = skbdesc->tx_rate_flags;
    retry_rates = test_bit(TXDONE_FALLBACK, &txdesc->flags) ?
        (txdesc->retry + 1) : 1;

    /*
     * Initialize TX status
     */
    memset(&tx_info->status, 0, sizeof(tx_info->status));
    tx_info->status.ack_signal = 0;

    /*
     * Frame was send with retries, hardware tried
     * different rates to send out the frame, at each
     * retry it lowered the rate 1 step except when the
     * lowest rate was used.
     */
    for (i = 0; i < retry_rates && i < IEEE80211_TX_MAX_RATES; i++) {
        tx_info->status.rates[i].idx = rate_idx - i;
        tx_info->status.rates[i].flags = rate_flags;

        if (rate_idx - i == 0) {
            /*
             * The lowest rate (index 0) was used until the
             * number of max retries was reached.
             */
            tx_info->status.rates[i].count = retry_rates - i;
            i++;
            break;
        }
        tx_info->status.rates[i].count = 1;
    }
    if (i < (IEEE80211_TX_MAX_RATES - 1))
        tx_info->status.rates[i].idx = -1; /* terminate */

    if (!(tx_info->flags & IEEE80211_TX_CTL_NO_ACK)) {
        if (success)
            tx_info->flags |= IEEE80211_TX_STAT_ACK;
        else
            rt2x00dev->low_level_stats.dot11ACKFailureCount++;
    }

    /*
     * Every single frame has it's own tx status, hence report
     * every frame as ampdu of size 1.
     *
     * TODO: if we can find out how many frames were aggregated
     * by the hw we could provide the real ampdu_len to mac80211
     * which would allow the rc algorithm to better decide on
     * which rates are suitable.
     */
    if (test_bit(TXDONE_AMPDU, &txdesc->flags) ||
        tx_info->flags & IEEE80211_TX_CTL_AMPDU) {
        tx_info->flags |= IEEE80211_TX_STAT_AMPDU;
        tx_info->status.ampdu_len = 1;
        tx_info->status.ampdu_ack_len = success ? 1 : 0;
        /*
         * TODO: Need to tear down BA session here
         * if not successful.
         */
    }

    if (rate_flags & IEEE80211_TX_RC_USE_RTS_CTS) {
        if (success)
            rt2x00dev->low_level_stats.dot11RTSSuccessCount++;
        else
            rt2x00dev->low_level_stats.dot11RTSFailureCount++;
    }

    /*
     * Only send the status report to mac80211 when it's a frame
     * that originated in mac80211. If this was a extra frame coming
     * through a mac80211 library call (RTS/CTS) then we should not
     * send the status report back.
     */
    if (!(skbdesc_flags & SKBDESC_NOT_MAC80211)) {
        if (test_bit(REQUIRE_TASKLET_CONTEXT, &rt2x00dev->cap_flags))
            ieee80211_tx_status(rt2x00dev->hw, entry->skb);
        else
            ieee80211_tx_status_ni(rt2x00dev->hw, entry->skb);
    } else
        dev_kfree_skb_any(entry->skb);

    /*
     * Make this entry available for reuse.
     */
    entry->skb = NULL;
    entry->flags = 0;

    rt2x00dev->ops->lib->clear_entry(entry);

    rt2x00queue_index_inc(entry, Q_INDEX_DONE);

    /*
     * If the data queue was below the threshold before the txdone
     * handler we must make sure the packet queue in the mac80211 stack
     * is reenabled when the txdone handler has finished. This has to be
     * serialized with rt2x00mac_tx(), otherwise we can wake up queue
     * before it was stopped.
     */
    spin_lock_bh(&entry->queue->tx_lock);
    if (!rt2x00queue_threshold(entry->queue))
        rt2x00queue_unpause_queue(entry->queue);
    spin_unlock_bh(&entry->queue->tx_lock);
}
EXPORT_SYMBOL_GPL(rt2x00lib_txdone);

void rt2x00lib_txdone_noinfo(struct queue_entry *entry, u32 status)
{
    struct txdone_entry_desc txdesc;

    txdesc.flags = 0;
    __set_bit(status, &txdesc.flags);
    txdesc.retry = 0;

    rt2x00lib_txdone(entry, &txdesc);
}
EXPORT_SYMBOL_GPL(rt2x00lib_txdone_noinfo);

static u8 *rt2x00lib_find_ie(u8 *data, unsigned int len, u8 ie)
{
    struct ieee80211_mgmt *mgmt = (void *)data;
    u8 *pos, *end;

    pos = (u8 *)mgmt->u.beacon.variable;
    end = data + len;
    while (pos < end) {
        if (pos + 2 + pos[1] > end)
            return NULL;

        if (pos[0] == ie)
            return pos;

        pos += 2 + pos[1];
    }

    return NULL;
}

static void rt2x00lib_sleep(struct work_struct *work)
{
    struct rt2x00_dev *rt2x00dev =
        container_of(work, struct rt2x00_dev, sleep_work);

    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
        return;

    /*
     * Check again is powersaving is enabled, to prevent races from delayed
     * work execution.
     */
    if (!test_bit(CONFIG_POWERSAVING, &rt2x00dev->flags))
        rt2x00lib_config(rt2x00dev, &rt2x00dev->hw->conf,
                 IEEE80211_CONF_CHANGE_PS);
}

static void rt2x00lib_rxdone_check_ps(struct rt2x00_dev *rt2x00dev,
                      struct sk_buff *skb,
                      struct rxdone_entry_desc *rxdesc)
{
    struct ieee80211_hdr *hdr = (void *) skb->data;
    struct ieee80211_tim_ie *tim_ie;
    u8 *tim;
    u8 tim_len;
    bool cam;

    /* If this is not a beacon, or if mac80211 has no powersaving
     * configured, or if the device is already in powersaving mode
     * we can exit now. */
    if (likely(!ieee80211_is_beacon(hdr->frame_control) ||
           !(rt2x00dev->hw->conf.flags & IEEE80211_CONF_PS)))
        return;

    /* min. beacon length + FCS_LEN */
    if (skb->len <= 40 + FCS_LEN)
        return;

    /* and only beacons from the associated BSSID, please */
    if (!(rxdesc->dev_flags & RXDONE_MY_BSS) ||
        !rt2x00dev->aid)
        return;

    rt2x00dev->last_beacon = jiffies;

    tim = rt2x00lib_find_ie(skb->data, skb->len - FCS_LEN, WLAN_EID_TIM);
    if (!tim)
        return;

    if (tim[1] < sizeof(*tim_ie))
        return;

    tim_len = tim[1];
    tim_ie = (struct ieee80211_tim_ie *) &tim[2];

    /* Check whenever the PHY can be turned off again. */

    /* 1. What about buffered unicast traffic for our AID? */
    cam = ieee80211_check_tim(tim_ie, tim_len, rt2x00dev->aid);

    /* 2. Maybe the AP wants to send multicast/broadcast data? */
    cam |= (tim_ie->bitmap_ctrl & 0x01);

    if (!cam && !test_bit(CONFIG_POWERSAVING, &rt2x00dev->flags))
        queue_work(rt2x00dev->workqueue, &rt2x00dev->sleep_work);
}

static int rt2x00lib_rxdone_read_signal(struct rt2x00_dev *rt2x00dev,
                    struct rxdone_entry_desc *rxdesc)
{
    struct ieee80211_supported_band *sband;
    const struct rt2x00_rate *rate;
    unsigned int i;
    int signal = rxdesc->signal;
    int type = (rxdesc->dev_flags & RXDONE_SIGNAL_MASK);

    switch (rxdesc->rate_mode) {
    case RATE_MODE_CCK:
    case RATE_MODE_OFDM:
        /*
         * For non-HT rates the MCS value needs to contain the
         * actually used rate modulation (CCK or OFDM).
         */
        if (rxdesc->dev_flags & RXDONE_SIGNAL_MCS)
            signal = RATE_MCS(rxdesc->rate_mode, signal);

        sband = &rt2x00dev->bands[rt2x00dev->curr_band];
        for (i = 0; i < sband->n_bitrates; i++) {
            rate = rt2x00_get_rate(sband->bitrates[i].hw_value);
            if (((type == RXDONE_SIGNAL_PLCP) &&
                 (rate->plcp == signal)) ||
                ((type == RXDONE_SIGNAL_BITRATE) &&
                  (rate->bitrate == signal)) ||
                ((type == RXDONE_SIGNAL_MCS) &&
                  (rate->mcs == signal))) {
                return i;
            }
        }
        break;
    case RATE_MODE_HT_MIX:
    case RATE_MODE_HT_GREENFIELD:
        if (signal >= 0 && signal <= 76)
            return signal;
        break;
    default:
        break;
    }

    WARNING(rt2x00dev, "Frame received with unrecognized signal, "
        "mode=0x%.4x, signal=0x%.4x, type=%d.\n",
        rxdesc->rate_mode, signal, type);
    return 0;
}

void rt2x00lib_rxdone(struct queue_entry *entry, gfp_t gfp)
{
    struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
    struct rxdone_entry_desc rxdesc;
    struct sk_buff *skb;
    struct ieee80211_rx_status *rx_status;
    unsigned int header_length;
    int rate_idx;

    if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
        !test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
        goto submit_entry;

    if (test_bit(ENTRY_DATA_IO_FAILED, &entry->flags))
        goto submit_entry;

    /*
     * Allocate a new sk_buffer. If no new buffer available, drop the
     * received frame and reuse the existing buffer.
     */
    skb = rt2x00queue_alloc_rxskb(entry, gfp);
    if (!skb)
        goto submit_entry;

    /*
     * Unmap the skb.
     */
    rt2x00queue_unmap_skb(entry);

    /*
     * Extract the RXD details.
     */
    memset(&rxdesc, 0, sizeof(rxdesc));
    rt2x00dev->ops->lib->fill_rxdone(entry, &rxdesc);

    /*
     * Check for valid size in case we get corrupted descriptor from
     * hardware.
     */
    if (unlikely(rxdesc.size == 0 ||
             rxdesc.size > entry->queue->data_size)) {
        ERROR(rt2x00dev, "Wrong frame size %d max %d.\n",
            rxdesc.size, entry->queue->data_size);
        dev_kfree_skb(entry->skb);
        goto renew_skb;
    }

    /*
     * The data behind the ieee80211 header must be
     * aligned on a 4 byte boundary.
     */
    header_length = ieee80211_get_hdrlen_from_skb(entry->skb);

    /*
     * Hardware might have stripped the IV/EIV/ICV data,
     * in that case it is possible that the data was
     * provided separately (through hardware descriptor)
     * in which case we should reinsert the data into the frame.
     */
    if ((rxdesc.dev_flags & RXDONE_CRYPTO_IV) &&
        (rxdesc.flags & RX_FLAG_IV_STRIPPED))
        rt2x00crypto_rx_insert_iv(entry->skb, header_length,
                      &rxdesc);
    else if (header_length &&
         (rxdesc.size > header_length) &&
         (rxdesc.dev_flags & RXDONE_L2PAD))
        rt2x00queue_remove_l2pad(entry->skb, header_length);

    /* Trim buffer to correct size */
    skb_trim(entry->skb, rxdesc.size);

    /*
     * Translate the signal to the correct bitrate index.
     */
    rate_idx = rt2x00lib_rxdone_read_signal(rt2x00dev, &rxdesc);
    if (rxdesc.rate_mode == RATE_MODE_HT_MIX ||
        rxdesc.rate_mode == RATE_MODE_HT_GREENFIELD)
        rxdesc.flags |= RX_FLAG_HT;

    /*
     * Check if this is a beacon, and more frames have been
     * buffered while we were in powersaving mode.
     */
    rt2x00lib_rxdone_check_ps(rt2x00dev, entry->skb, &rxdesc);

    /*
     * Update extra components
     */
    rt2x00link_update_stats(rt2x00dev, entry->skb, &rxdesc);
    rt2x00debug_update_crypto(rt2x00dev, &rxdesc);
    rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_RXDONE, entry->skb);

    /*
     * Initialize RX status information, and send frame
     * to mac80211.
     */
    rx_status = IEEE80211_SKB_RXCB(entry->skb);
    rx_status->mactime = rxdesc.timestamp;
    rx_status->band = rt2x00dev->curr_band;
    rx_status->freq = rt2x00dev->curr_freq;
    rx_status->rate_idx = rate_idx;
    rx_status->signal = rxdesc.rssi;
    rx_status->flag = rxdesc.flags;
    rx_status->antenna = rt2x00dev->link.ant.active.rx;

    ieee80211_rx_ni(rt2x00dev->hw, entry->skb);

renew_skb:
    /*
     * Replace the skb with the freshly allocated one.
     */
    entry->skb = skb;

submit_entry:
    entry->flags = 0;
    rt2x00queue_index_inc(entry, Q_INDEX_DONE);
    if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
        test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
        rt2x00dev->ops->lib->clear_entry(entry);
}
EXPORT_SYMBOL_GPL(rt2x00lib_rxdone);

/*
 * Driver initialization handlers.
 */
const struct rt2x00_rate rt2x00_supported_rates[12] = {
    {
        .flags = DEV_RATE_CCK,
        .bitrate = 10,
        .ratemask = BIT(0),
        .plcp = 0x00,
        .mcs = RATE_MCS(RATE_MODE_CCK, 0),
    },
    {
        .flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
        .bitrate = 20,
        .ratemask = BIT(1),
        .plcp = 0x01,
        .mcs = RATE_MCS(RATE_MODE_CCK, 1),
    },
    {
        .flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
        .bitrate = 55,
        .ratemask = BIT(2),
        .plcp = 0x02,
        .mcs = RATE_MCS(RATE_MODE_CCK, 2),
    },
    {
        .flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
        .bitrate = 110,
        .ratemask = BIT(3),
        .plcp = 0x03,
        .mcs = RATE_MCS(RATE_MODE_CCK, 3),
    },
    {
        .flags = DEV_RATE_OFDM,
        .bitrate = 60,
        .ratemask = BIT(4),
        .plcp = 0x0b,
        .mcs = RATE_MCS(RATE_MODE_OFDM, 0),
    },
    {
        .flags = DEV_RATE_OFDM,
        .bitrate = 90,
        .ratemask = BIT(5),
        .plcp = 0x0f,
        .mcs = RATE_MCS(RATE_MODE_OFDM, 1),
    },
    {
        .flags = DEV_RATE_OFDM,
        .bitrate = 120,
        .ratemask = BIT(6),
        .plcp = 0x0a,
        .mcs = RATE_MCS(RATE_MODE_OFDM, 2),
    },
    {
        .flags = DEV_RATE_OFDM,
        .bitrate = 180,
        .ratemask = BIT(7),
        .plcp = 0x0e,
        .mcs = RATE_MCS(RATE_MODE_OFDM, 3),
    },
    {
        .flags = DEV_RATE_OFDM,
        .bitrate = 240,
        .ratemask = BIT(8),
        .plcp = 0x09,
        .mcs = RATE_MCS(RATE_MODE_OFDM, 4),
    },
    {
        .flags = DEV_RATE_OFDM,
        .bitrate = 360,
        .ratemask = BIT(9),
        .plcp = 0x0d,
        .mcs = RATE_MCS(RATE_MODE_OFDM, 5),
    },
    {
        .flags = DEV_RATE_OFDM,
        .bitrate = 480,
        .ratemask = BIT(10),
        .plcp = 0x08,
        .mcs = RATE_MCS(RATE_MODE_OFDM, 6),
    },
    {
        .flags = DEV_RATE_OFDM,
        .bitrate = 540,
        .ratemask = BIT(11),
        .plcp = 0x0c,
        .mcs = RATE_MCS(RATE_MODE_OFDM, 7),
    },
};

static void rt2x00lib_channel(struct ieee80211_channel *entry,
                  const int channel, const int tx_power,
                  const int value)
{
    /* XXX: this assumption about the band is wrong for 802.11j */
    entry->band = channel <= 14 ? IEEE80211_BAND_2GHZ : IEEE80211_BAND_5GHZ;
    entry->center_freq = ieee80211_channel_to_frequency(channel,
                                entry->band);
    entry->hw_value = value;
    entry->max_power = tx_power;
    entry->max_antenna_gain = 0xff;
}

static void rt2x00lib_rate(struct ieee80211_rate *entry,
               const u16 index, const struct rt2x00_rate *rate)
{
    entry->flags = 0;
    entry->bitrate = rate->bitrate;
    entry->hw_value = index;
    entry->hw_value_short = index;

    if (rate->flags & DEV_RATE_SHORT_PREAMBLE)
        entry->flags |= IEEE80211_RATE_SHORT_PREAMBLE;
}

static int rt2x00lib_probe_hw_modes(struct rt2x00_dev *rt2x00dev,
                    struct hw_mode_spec *spec)
{
    struct ieee80211_hw *hw = rt2x00dev->hw;
    struct ieee80211_channel *channels;
    struct ieee80211_rate *rates;
    unsigned int num_rates;
    unsigned int i;

    num_rates = 0;
    if (spec->supported_rates & SUPPORT_RATE_CCK)
        num_rates += 4;
    if (spec->supported_rates & SUPPORT_RATE_OFDM)
        num_rates += 8;

    channels = kcalloc(spec->num_channels, sizeof(*channels), GFP_KERNEL);
    if (!channels)
        return -ENOMEM;

    rates = kcalloc(num_rates, sizeof(*rates), GFP_KERNEL);
    if (!rates)
        goto exit_free_channels;

    /*
     * Initialize Rate list.
     */
    for (i = 0; i < num_rates; i++)
        rt2x00lib_rate(&rates[i], i, rt2x00_get_rate(i));

    /*
     * Initialize Channel list.
     */
    for (i = 0; i < spec->num_channels; i++) {
        rt2x00lib_channel(&channels[i],
                  spec->channels[i].channel,
                  spec->channels_info[i].max_power, i);
    }

    /*
     * Intitialize 802.11b, 802.11g
     * Rates: CCK, OFDM.
     * Channels: 2.4 GHz
     */
    if (spec->supported_bands & SUPPORT_BAND_2GHZ) {
        rt2x00dev->bands[IEEE80211_BAND_2GHZ].n_channels = 14;
        rt2x00dev->bands[IEEE80211_BAND_2GHZ].n_bitrates = num_rates;
        rt2x00dev->bands[IEEE80211_BAND_2GHZ].channels = channels;
        rt2x00dev->bands[IEEE80211_BAND_2GHZ].bitrates = rates;
        hw->wiphy->bands[IEEE80211_BAND_2GHZ] =
            &rt2x00dev->bands[IEEE80211_BAND_2GHZ];
        memcpy(&rt2x00dev->bands[IEEE80211_BAND_2GHZ].ht_cap,
               &spec->ht, sizeof(spec->ht));
    }

    /*
     * Intitialize 802.11a
     * Rates: OFDM.
     * Channels: OFDM, UNII, HiperLAN2.
     */
    if (spec->supported_bands & SUPPORT_BAND_5GHZ) {
        rt2x00dev->bands[IEEE80211_BAND_5GHZ].n_channels =
            spec->num_channels - 14;
        rt2x00dev->bands[IEEE80211_BAND_5GHZ].n_bitrates =
            num_rates - 4;
        rt2x00dev->bands[IEEE80211_BAND_5GHZ].channels = &channels[14];
        rt2x00dev->bands[IEEE80211_BAND_5GHZ].bitrates = &rates[4];
        hw->wiphy->bands[IEEE80211_BAND_5GHZ] =
            &rt2x00dev->bands[IEEE80211_BAND_5GHZ];
        memcpy(&rt2x00dev->bands[IEEE80211_BAND_5GHZ].ht_cap,
               &spec->ht, sizeof(spec->ht));
    }

    return 0;

 exit_free_channels:
    kfree(channels);
    ERROR(rt2x00dev, "Allocation ieee80211 modes failed.\n");
    return -ENOMEM;
}

static void rt2x00lib_remove_hw(struct rt2x00_dev *rt2x00dev)
{
    if (test_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags))
        ieee80211_unregister_hw(rt2x00dev->hw);

    if (likely(rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ])) {
        kfree(rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ]->channels);
        kfree(rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ]->bitrates);
        rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ] = NULL;
        rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_5GHZ] = NULL;
    }

    kfree(rt2x00dev->spec.channels_info);
}

static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev)
{
    struct hw_mode_spec *spec = &rt2x00dev->spec;
    int status;

    if (test_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags))
        return 0;

    /*
     * Initialize HW modes.
     */
    status = rt2x00lib_probe_hw_modes(rt2x00dev, spec);
    if (status)
        return status;

    /*
     * Initialize HW fields.
     */
    rt2x00dev->hw->queues = rt2x00dev->ops->tx_queues;

    /*
     * Initialize extra TX headroom required.
     */
    rt2x00dev->hw->extra_tx_headroom =
        max_t(unsigned int, IEEE80211_TX_STATUS_HEADROOM,
              rt2x00dev->ops->extra_tx_headroom);

    /*
     * Take TX headroom required for alignment into account.
     */
    if (test_bit(REQUIRE_L2PAD, &rt2x00dev->cap_flags))
        rt2x00dev->hw->extra_tx_headroom += RT2X00_L2PAD_SIZE;
    else if (test_bit(REQUIRE_DMA, &rt2x00dev->cap_flags))
        rt2x00dev->hw->extra_tx_headroom += RT2X00_ALIGN_SIZE;

    /*
     * Tell mac80211 about the size of our private STA structure.
     */
    rt2x00dev->hw->sta_data_size = sizeof(struct rt2x00_sta);

    /*
     * Allocate tx status FIFO for driver use.
     */
    if (test_bit(REQUIRE_TXSTATUS_FIFO, &rt2x00dev->cap_flags)) {
        /*
         * Allocate the txstatus fifo. In the worst case the tx
         * status fifo has to hold the tx status of all entries
         * in all tx queues. Hence, calculate the kfifo size as
         * tx_queues * entry_num and round up to the nearest
         * power of 2.
         */
        int kfifo_size =
            roundup_pow_of_two(rt2x00dev->ops->tx_queues *
                       rt2x00dev->ops->tx->entry_num *
                       sizeof(u32));

        status = kfifo_alloc(&rt2x00dev->txstatus_fifo, kfifo_size,
                     GFP_KERNEL);
        if (status)
            return status;
    }

    /*
     * Initialize tasklets if used by the driver. Tasklets are
     * disabled until the interrupts are turned on. The driver
     * has to handle that.
     */
#define RT2X00_TASKLET_INIT(taskletname) \
    if (rt2x00dev->ops->lib->taskletname) { \
        tasklet_init(&rt2x00dev->taskletname, \
                 rt2x00dev->ops->lib->taskletname, \
                 (unsigned long)rt2x00dev); \
    }

    RT2X00_TASKLET_INIT(txstatus_tasklet);
    RT2X00_TASKLET_INIT(pretbtt_tasklet);
    RT2X00_TASKLET_INIT(tbtt_tasklet);
    RT2X00_TASKLET_INIT(rxdone_tasklet);
    RT2X00_TASKLET_INIT(autowake_tasklet);

#undef RT2X00_TASKLET_INIT

    /*
     * Register HW.
     */
    status = ieee80211_register_hw(rt2x00dev->hw);
    if (status)
        return status;

    set_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags);

    return 0;
}

/*
 * Initialization/uninitialization handlers.
 */
static void rt2x00lib_uninitialize(struct rt2x00_dev *rt2x00dev)
{
    if (!test_and_clear_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags))
        return;

    /*
     * Unregister extra components.
     */
    rt2x00rfkill_unregister(rt2x00dev);

    /*
     * Allow the HW to uninitialize.
     */
    rt2x00dev->ops->lib->uninitialize(rt2x00dev);

    /*
     * Free allocated queue entries.
     */
    rt2x00queue_uninitialize(rt2x00dev);
}

static int rt2x00lib_initialize(struct rt2x00_dev *rt2x00dev)
{
    int status;

    if (test_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags))
        return 0;

    /*
     * Allocate all queue entries.
     */
    status = rt2x00queue_initialize(rt2x00dev);
    if (status)
        return status;

    /*
     * Initialize the device.
     */
    status = rt2x00dev->ops->lib->initialize(rt2x00dev);
    if (status) {
        rt2x00queue_uninitialize(rt2x00dev);
        return status;
    }

    set_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags);

    return 0;
}

int rt2x00lib_start(struct rt2x00_dev *rt2x00dev)
{
    int retval;

    if (test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
        return 0;

    /*
     * If this is the first interface which is added,
     * we should load the firmware now.
     */
    retval = rt2x00lib_load_firmware(rt2x00dev);
    if (retval)
        return retval;

    /*
     * Initialize the device.
     */
    retval = rt2x00lib_initialize(rt2x00dev);
    if (retval)
        return retval;

    rt2x00dev->intf_ap_count = 0;
    rt2x00dev->intf_sta_count = 0;
    rt2x00dev->intf_associated = 0;

    /* Enable the radio */
    retval = rt2x00lib_enable_radio(rt2x00dev);
    if (retval)
        return retval;

    set_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags);

    return 0;
}

void rt2x00lib_stop(struct rt2x00_dev *rt2x00dev)
{
    if (!test_and_clear_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
        return;

    /*
     * Perhaps we can add something smarter here,
     * but for now just disabling the radio should do.
     */
    rt2x00lib_disable_radio(rt2x00dev);

    rt2x00dev->intf_ap_count = 0;
    rt2x00dev->intf_sta_count = 0;
    rt2x00dev->intf_associated = 0;
}

static inline void rt2x00lib_set_if_combinations(struct rt2x00_dev *rt2x00dev)
{
    struct ieee80211_iface_limit *if_limit;
    struct ieee80211_iface_combination *if_combination;

    /*
     * Build up AP interface limits structure.
     */
    if_limit = &rt2x00dev->if_limits_ap;
    if_limit->max = rt2x00dev->ops->max_ap_intf;
    if_limit->types = BIT(NL80211_IFTYPE_AP);

    /*
     * Build up AP interface combinations structure.
     */
    if_combination = &rt2x00dev->if_combinations[IF_COMB_AP];
    if_combination->limits = if_limit;
    if_combination->n_limits = 1;
    if_combination->max_interfaces = if_limit->max;
    if_combination->num_different_channels = 1;

    /*
     * Finally, specify the possible combinations to mac80211.
     */
    rt2x00dev->hw->wiphy->iface_combinations = rt2x00dev->if_combinations;
    rt2x00dev->hw->wiphy->n_iface_combinations = 1;
}

/*
 * driver allocation handlers.
 */
int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
{
    int retval = -ENOMEM;

    /*
     * Set possible interface combinations.
     */
    rt2x00lib_set_if_combinations(rt2x00dev);

    /*
     * Allocate the driver data memory, if necessary.
     */
    if (rt2x00dev->ops->drv_data_size > 0) {
        rt2x00dev->drv_data = kzalloc(rt2x00dev->ops->drv_data_size,
                                  GFP_KERNEL);
        if (!rt2x00dev->drv_data) {
            retval = -ENOMEM;
            goto exit;
        }
    }

    spin_lock_init(&rt2x00dev->irqmask_lock);
    mutex_init(&rt2x00dev->csr_mutex);

    set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);

    /*
     * Make room for rt2x00_intf inside the per-interface
     * structure ieee80211_vif.
     */
    rt2x00dev->hw->vif_data_size = sizeof(struct rt2x00_intf);

    /*
     * Determine which operating modes are supported, all modes
     * which require beaconing, depend on the availability of
     * beacon entries.
     */
    rt2x00dev->hw->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION);
    if (rt2x00dev->ops->bcn->entry_num > 0)
        rt2x00dev->hw->wiphy->interface_modes |=
            BIT(NL80211_IFTYPE_ADHOC) |
            BIT(NL80211_IFTYPE_AP) |
            BIT(NL80211_IFTYPE_MESH_POINT) |
            BIT(NL80211_IFTYPE_WDS);

    rt2x00dev->hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;

    /*
     * Initialize work.
     */
    rt2x00dev->workqueue =
        alloc_ordered_workqueue(wiphy_name(rt2x00dev->hw->wiphy), 0);
    if (!rt2x00dev->workqueue) {
        retval = -ENOMEM;
        goto exit;
    }

    INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled);
    INIT_DELAYED_WORK(&rt2x00dev->autowakeup_work, rt2x00lib_autowakeup);
    INIT_WORK(&rt2x00dev->sleep_work, rt2x00lib_sleep);

    /*
     * Let the driver probe the device to detect the capabilities.
     */
    retval = rt2x00dev->ops->lib->probe_hw(rt2x00dev);
    if (retval) {
        ERROR(rt2x00dev, "Failed to allocate device.\n");
        goto exit;
    }

    /*
     * Allocate queue array.
     */
    retval = rt2x00queue_allocate(rt2x00dev);
    if (retval)
        goto exit;

    /*
     * Initialize ieee80211 structure.
     */
    retval = rt2x00lib_probe_hw(rt2x00dev);
    if (retval) {
        ERROR(rt2x00dev, "Failed to initialize hw.\n");
        goto exit;
    }

    /*
     * Register extra components.
     */
    rt2x00link_register(rt2x00dev);
    rt2x00leds_register(rt2x00dev);
    rt2x00debug_register(rt2x00dev);
    rt2x00rfkill_register(rt2x00dev);

    return 0;

exit:
    rt2x00lib_remove_dev(rt2x00dev);

    return retval;
}
EXPORT_SYMBOL_GPL(rt2x00lib_probe_dev);

void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev)
{
    clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);

    /*
     * Disable radio.
     */
    rt2x00lib_disable_radio(rt2x00dev);

    /*
     * Stop all work.
     */
    cancel_work_sync(&rt2x00dev->intf_work);
    cancel_delayed_work_sync(&rt2x00dev->autowakeup_work);
    cancel_work_sync(&rt2x00dev->sleep_work);
    if (rt2x00_is_usb(rt2x00dev)) {
        hrtimer_cancel(&rt2x00dev->txstatus_timer);
        cancel_work_sync(&rt2x00dev->rxdone_work);
        cancel_work_sync(&rt2x00dev->txdone_work);
    }
    if (rt2x00dev->workqueue)
        destroy_workqueue(rt2x00dev->workqueue);

    /*
     * Free the tx status fifo.
     */
    kfifo_free(&rt2x00dev->txstatus_fifo);

    /*
     * Kill the tx status tasklet.
     */
    tasklet_kill(&rt2x00dev->txstatus_tasklet);
    tasklet_kill(&rt2x00dev->pretbtt_tasklet);
    tasklet_kill(&rt2x00dev->tbtt_tasklet);
    tasklet_kill(&rt2x00dev->rxdone_tasklet);
    tasklet_kill(&rt2x00dev->autowake_tasklet);

    /*
     * Uninitialize device.
     */
    rt2x00lib_uninitialize(rt2x00dev);

    /*
     * Free extra components
     */
    rt2x00debug_deregister(rt2x00dev);
    rt2x00leds_unregister(rt2x00dev);

    /*
     * Free ieee80211_hw memory.
     */
    rt2x00lib_remove_hw(rt2x00dev);

    /*
     * Free firmware image.
     */
    rt2x00lib_free_firmware(rt2x00dev);

    /*
     * Free queue structures.
     */
    rt2x00queue_free(rt2x00dev);

    /*
     * Free the driver data.
     */
    if (rt2x00dev->drv_data)
        kfree(rt2x00dev->drv_data);
}
EXPORT_SYMBOL_GPL(rt2x00lib_remove_dev);

/*
 * Device state handlers
 */
#ifdef CONFIG_PM
int rt2x00lib_suspend(struct rt2x00_dev *rt2x00dev, pm_message_t state)
{
    NOTICE(rt2x00dev, "Going to sleep.\n");

    /*
     * Prevent mac80211 from accessing driver while suspended.
     */
    if (!test_and_clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
        return 0;

    /*
     * Cleanup as much as possible.
     */
    rt2x00lib_uninitialize(rt2x00dev);

    /*
     * Suspend/disable extra components.
     */
    rt2x00leds_suspend(rt2x00dev);
    rt2x00debug_deregister(rt2x00dev);

    /*
     * Set device mode to sleep for power management,
     * on some hardware this call seems to consistently fail.
     * From the specifications it is hard to tell why it fails,
     * and if this is a "bad thing".
     * Overall it is safe to just ignore the failure and
     * continue suspending. The only downside is that the
     * device will not be in optimal power save mode, but with
     * the radio and the other components already disabled the
     * device is as good as disabled.
     */
    if (rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_SLEEP))
        WARNING(rt2x00dev, "Device failed to enter sleep state, "
            "continue suspending.\n");

    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00lib_suspend);

int rt2x00lib_resume(struct rt2x00_dev *rt2x00dev)
{
    NOTICE(rt2x00dev, "Waking up.\n");

    /*
     * Restore/enable extra components.
     */
    rt2x00debug_register(rt2x00dev);
    rt2x00leds_resume(rt2x00dev);

    /*
     * We are ready again to receive requests from mac80211.
     */
    set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);

    return 0;
}
EXPORT_SYMBOL_GPL(rt2x00lib_resume);
#endif /* CONFIG_PM */

/*
 * rt2x00lib module information.
 */
MODULE_AUTHOR(DRV_PROJECT);
MODULE_VERSION(DRV_VERSION);
MODULE_DESCRIPTION("rt2x00 library");
MODULE_LICENSE("GPL");