ath9k: Implement hw_scan support

Implement hw_scan support for enabling multi-channel cuncurrency.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Rajkumar Manoharan <rmanohar@qti.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

6 files changed, 255 insertions, 2 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index d5a586bbab7c..d6b0c4e55c95 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -35,6 +35,7 @@ extern struct ieee80211_ops ath9k_ops;
 extern int ath9k_modparam_nohwcrypt;
 extern int led_blink;
 extern bool is_ath9k_unloaded;
+extern int ath9k_use_chanctx;
 
 /*************************/
 /* Descriptor Management */
@@ -332,12 +333,34 @@ struct ath_chanctx {
         bool active;
 };
 
+enum ath_offchannel_state {
+        ATH_OFFCHANNEL_IDLE,
+        ATH_OFFCHANNEL_PROBE_SEND,
+        ATH_OFFCHANNEL_PROBE_WAIT,
+        ATH_OFFCHANNEL_SUSPEND,
+};
+
+struct ath_offchannel {
+        struct ath_chanctx chan;
+        struct timer_list timer;
+        struct cfg80211_scan_request *scan_req;
+        struct ieee80211_vif *scan_vif;
+        int scan_idx;
+        enum ath_offchannel_state state;
+};
+
+void ath9k_fill_chanctx_ops(void);
 void ath_chanctx_init(struct ath_softc *sc);
 void ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx,
                              struct cfg80211_chan_def *chandef);
 void ath_chanctx_switch(struct ath_softc *sc, struct ath_chanctx *ctx,
                         struct cfg80211_chan_def *chandef);
 void ath_chanctx_check_active(struct ath_softc *sc, struct ath_chanctx *ctx);
+void ath_offchannel_timer(unsigned long data);
+void ath_offchannel_channel_change(struct ath_softc *sc);
+void ath_chanctx_offchan_switch(struct ath_softc *sc,
+                                struct ieee80211_channel *chan);
+struct ath_chanctx *ath_chanctx_get_oper_chan(struct ath_softc *sc);
 
 int ath_reset_internal(struct ath_softc *sc, struct ath9k_channel *hchan);
 int ath_startrecv(struct ath_softc *sc);
@@ -771,6 +794,7 @@ struct ath_softc {
         struct ath_chanctx *cur_chan;
         struct ath_chanctx *next_chan;
         spinlock_t chan_lock;
+        struct ath_offchannel offchannel;
 
 #ifdef CONFIG_MAC80211_LEDS
         bool led_registered;
diff --git a/drivers/net/wireless/ath/ath9k/channel.c b/drivers/net/wireless/ath/ath9k/channel.c
index 26fc98b3495b..c679a26045ac 100644
--- a/drivers/net/wireless/ath/ath9k/channel.c
+++ b/drivers/net/wireless/ath/ath9k/channel.c
@@ -228,6 +228,7 @@ void ath_chanctx_work(struct work_struct *work)
         if (send_ps)
                 ath_chanctx_send_ps_frame(sc, false);
 
+        ath_offchannel_channel_change(sc);
         mutex_unlock(&sc->mutex);
 }
 
@@ -253,6 +254,14 @@ void ath_chanctx_init(struct ath_softc *sc)
                         INIT_LIST_HEAD(&ctx->acq[j]);
         }
         sc->cur_chan = &sc->chanctx[0];
+        ctx = &sc->offchannel.chan;
+        cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
+        INIT_LIST_HEAD(&ctx->vifs);
+        ctx->txpower = ATH_TXPOWER_MAX;
+        for (j = 0; j < ARRAY_SIZE(ctx->acq); j++)
+                INIT_LIST_HEAD(&ctx->acq[j]);
+        sc->offchannel.chan.offchannel = true;
+
 }
 
 void ath_chanctx_switch(struct ath_softc *sc, struct ath_chanctx *ctx,
@@ -283,3 +292,25 @@ void ath_chanctx_set_channel(struct ath_softc *sc, struct ath_chanctx *ctx,
 
         ath_set_channel(sc);
 }
+
+struct ath_chanctx *ath_chanctx_get_oper_chan(struct ath_softc *sc)
+{
+        u8 i;
+
+        for (i = 0; i < ARRAY_SIZE(sc->chanctx); i++) {
+                if (!list_empty(&sc->chanctx[i].vifs))
+                        return &sc->chanctx[i];
+        }
+
+        return &sc->chanctx[0];
+}
+
+void ath_chanctx_offchan_switch(struct ath_softc *sc,
+                                struct ieee80211_channel *chan)
+{
+        struct cfg80211_chan_def chandef;
+
+        cfg80211_chandef_create(&chandef, chan, NL80211_CHAN_NO_HT);
+
+        ath_chanctx_switch(sc, &sc->offchannel.chan, &chandef);
+}
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 8bd3e422b82b..9f5e1e4931af 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -61,7 +61,7 @@ static int ath9k_ps_enable;
 module_param_named(ps_enable, ath9k_ps_enable, int, 0444);
 MODULE_PARM_DESC(ps_enable, "Enable WLAN PowerSave");
 
-static int ath9k_use_chanctx;
+int ath9k_use_chanctx;
 module_param_named(use_chanctx, ath9k_use_chanctx, int, 0444);
 MODULE_PARM_DESC(use_chanctx, "Enable channel context for concurrency");
 
@@ -566,6 +566,8 @@ static int ath9k_init_softc(u16 devid, struct ath_softc *sc,
         INIT_WORK(&sc->paprd_work, ath_paprd_calibrate);
         INIT_WORK(&sc->chanctx_work, ath_chanctx_work);
         INIT_DELAYED_WORK(&sc->hw_pll_work, ath_hw_pll_work);
+        setup_timer(&sc->offchannel.timer, ath_offchannel_timer,
+                    (unsigned long)sc);
 
         /*
          * Cache line size is used to size and align various
@@ -745,8 +747,11 @@ static void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)
                 if (!ath9k_use_chanctx) {
                         hw->wiphy->n_iface_combinations = ARRAY_SIZE(if_comb);
                         hw->wiphy->interface_modes |= BIT(NL80211_IFTYPE_WDS);
-                } else
+                } else {
                         hw->wiphy->n_iface_combinations = 1;
+                        hw->wiphy->max_scan_ssids = 255;
+                        hw->wiphy->max_scan_ie_len = IEEE80211_MAX_DATA_LEN;
+                }
         }
 
         hw->wiphy->flags &= ~WIPHY_FLAG_PS_ON_BY_DEFAULT;
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index d8a4510f963a..5da62ef1fc26 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -2159,6 +2159,193 @@ static void ath9k_sw_scan_complete(struct ieee80211_hw *hw)
         clear_bit(ATH_OP_SCANNING, &common->op_flags);
 }
 
+static void
+ath_scan_next_channel(struct ath_softc *sc)
+{
+        struct cfg80211_scan_request *req = sc->offchannel.scan_req;
+        struct ieee80211_channel *chan;
+
+        if (sc->offchannel.scan_idx >= req->n_channels) {
+                sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
+                ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc), NULL);
+                return;
+        }
+
+        chan = req->channels[sc->offchannel.scan_idx++];
+        sc->offchannel.state = ATH_OFFCHANNEL_PROBE_SEND;
+        ath_chanctx_offchan_switch(sc, chan);
+}
+
+static void ath_scan_complete(struct ath_softc *sc, bool abort)
+{
+        struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+
+        ath_chanctx_switch(sc, ath_chanctx_get_oper_chan(sc), NULL);
+        sc->offchannel.scan_req = NULL;
+        sc->offchannel.scan_vif = NULL;
+        sc->offchannel.state = ATH_OFFCHANNEL_IDLE;
+        ieee80211_scan_completed(sc->hw, abort);
+        clear_bit(ATH_OP_SCANNING, &common->op_flags);
+        ath9k_ps_restore(sc);
+
+        if (!sc->ps_idle)
+                return;
+
+        ath_cancel_work(sc);
+}
+
+static void ath_scan_send_probe(struct ath_softc *sc,
+                                struct cfg80211_ssid *ssid)
+{
+        struct cfg80211_scan_request *req = sc->offchannel.scan_req;
+        struct ieee80211_vif *vif = sc->offchannel.scan_vif;
+        struct ath_tx_control txctl = {};
+        struct sk_buff *skb;
+        struct ieee80211_tx_info *info;
+        int band = sc->offchannel.chan.chandef.chan->band;
+
+        skb = ieee80211_probereq_get(sc->hw, vif,
+                        ssid->ssid, ssid->ssid_len, req->ie_len);
+        if (!skb)
+                return;
+
+        info = IEEE80211_SKB_CB(skb);
+        if (req->no_cck)
+                info->flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
+
+        if (req->ie_len)
+                memcpy(skb_put(skb, req->ie_len), req->ie, req->ie_len);
+
+        skb_set_queue_mapping(skb, IEEE80211_AC_VO);
+
+        if (!ieee80211_tx_prepare_skb(sc->hw, vif, skb, band, NULL))
+                goto error;
+
+        txctl.txq = sc->tx.txq_map[IEEE80211_AC_VO];
+        txctl.force_channel = true;
+        if (ath_tx_start(sc->hw, skb, &txctl))
+                goto error;
+
+        return;
+
+error:
+        ieee80211_free_txskb(sc->hw, skb);
+}
+
+static void ath_scan_channel_start(struct ath_softc *sc)
+{
+        struct cfg80211_scan_request *req = sc->offchannel.scan_req;
+        int i, dwell;
+
+        if ((sc->cur_chan->chandef.chan->flags & IEEE80211_CHAN_NO_IR) ||
+                        !req->n_ssids) {
+                dwell = HZ / 9; /* ~110 ms */
+        } else {
+                dwell = HZ / 16; /* ~60 ms */
+
+                for (i = 0; i < req->n_ssids; i++)
+                        ath_scan_send_probe(sc, &req->ssids[i]);
+        }
+
+        sc->offchannel.state = ATH_OFFCHANNEL_PROBE_WAIT;
+        mod_timer(&sc->offchannel.timer, jiffies + dwell);
+}
+
+void ath_offchannel_channel_change(struct ath_softc *sc)
+{
+        if (!sc->offchannel.scan_req)
+                return;
+
+        switch (sc->offchannel.state) {
+        case ATH_OFFCHANNEL_PROBE_SEND:
+                if (sc->cur_chan->chandef.chan !=
+                    sc->offchannel.chan.chandef.chan)
+                        return;
+
+                ath_scan_channel_start(sc);
+                break;
+        case ATH_OFFCHANNEL_IDLE:
+                ath_scan_complete(sc, false);
+                break;
+        default:
+                break;
+        }
+}
+
+void ath_offchannel_timer(unsigned long data)
+{
+        struct ath_softc *sc = (struct ath_softc *)data;
+        struct ath_chanctx *ctx = ath_chanctx_get_oper_chan(sc);
+
+        if (!sc->offchannel.scan_req)
+                return;
+
+        switch (sc->offchannel.state) {
+        case ATH_OFFCHANNEL_PROBE_WAIT:
+                if (ctx->active) {
+                        sc->offchannel.state = ATH_OFFCHANNEL_SUSPEND;
+                        ath_chanctx_switch(sc, ctx, NULL);
+                        mod_timer(&sc->offchannel.timer, jiffies + HZ / 10);
+                        break;
+                }
+                /* fall through */
+        case ATH_OFFCHANNEL_SUSPEND:
+                ath_scan_next_channel(sc);
+                break;
+        default:
+                break;
+        }
+}
+
+static int ath9k_hw_scan(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
+                         struct cfg80211_scan_request *req)
+{
+        struct ath_softc *sc = hw->priv;
+        struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+        int ret = 0;
+
+        mutex_lock(&sc->mutex);
+
+        if (WARN_ON(sc->offchannel.scan_req)) {
+                ret = -EBUSY;
+                goto out;
+        }
+
+        ath9k_ps_wakeup(sc);
+        set_bit(ATH_OP_SCANNING, &common->op_flags);
+        sc->offchannel.scan_vif = vif;
+        sc->offchannel.scan_req = req;
+        sc->offchannel.scan_idx = 0;
+        sc->offchannel.chan.txpower = vif->bss_conf.txpower;
+
+        ath_scan_next_channel(sc);
+
+out:
+        mutex_unlock(&sc->mutex);
+
+        return ret;
+}
+
+static void ath9k_cancel_hw_scan(struct ieee80211_hw *hw,
+                                 struct ieee80211_vif *vif)
+{
+        struct ath_softc *sc = hw->priv;
+
+        mutex_lock(&sc->mutex);
+        del_timer_sync(&sc->offchannel.timer);
+        ath_scan_complete(sc, true);
+        mutex_unlock(&sc->mutex);
+}
+
+void ath9k_fill_chanctx_ops(void)
+{
+        if (!ath9k_use_chanctx)
+                return;
+
+        ath9k_ops.hw_scan = ath9k_hw_scan;
+        ath9k_ops.cancel_hw_scan = ath9k_cancel_hw_scan;
+}
+
 struct ieee80211_ops ath9k_ops = {
         .tx                 = ath9k_tx,
         .start              = ath9k_start,
diff --git a/drivers/net/wireless/ath/ath9k/pci.c b/drivers/net/wireless/ath/ath9k/pci.c
index 4dec09e565ed..7a2b2c5caced 100644
--- a/drivers/net/wireless/ath/ath9k/pci.c
+++ b/drivers/net/wireless/ath/ath9k/pci.c
@@ -843,6 +843,7 @@ static int ath_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
                 return -ENODEV;
         }
 
+        ath9k_fill_chanctx_ops();
         hw = ieee80211_alloc_hw(sizeof(struct ath_softc), &ath9k_ops);
         if (!hw) {
                 dev_err(&pdev->dev, "No memory for ieee80211_hw\n");
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index de5684a33dd7..fec9e0b42f5d 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -374,6 +374,7 @@ void ath_rx_cleanup(struct ath_softc *sc)
 
 u32 ath_calcrxfilter(struct ath_softc *sc)
 {
+        struct ath_common *common = ath9k_hw_common(sc->sc_ah);
         u32 rfilt;
 
         if (config_enabled(CONFIG_ATH9K_TX99))
@@ -424,6 +425,10 @@ u32 ath_calcrxfilter(struct ath_softc *sc)
         if (AR_SREV_9550(sc->sc_ah) || AR_SREV_9531(sc->sc_ah))
                 rfilt |= ATH9K_RX_FILTER_4ADDRESS;
 
+        if (ath9k_use_chanctx &&
+            test_bit(ATH_OP_SCANNING, &common->op_flags))
+                rfilt |= ATH9K_RX_FILTER_BEACON;
+
         return rfilt;
 
 }