ath9k: Use mac80211 for multicast power save buffering

Replace the internal ath9k implementation of multicast/broadcast frame
power save buffering (AP mode) in ath9k with use of mac80211
ieee80211_get_buffered_bc() mechanism. This removes quite a bit of
duplicated functionality and simplifies the driver part.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

6 files changed, 82 insertions, 183 deletions

diff --git a/drivers/net/wireless/ath9k/ath9k.h b/drivers/net/wireless/ath9k/ath9k.h
index 18028a3abc58..841893b0b4d4 100644
--- a/drivers/net/wireless/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath9k/ath9k.h
@@ -144,6 +144,7 @@ struct ath_desc {
 #define ATH9K_TXDESC_EXT_AND_CTL        0x0080
 #define ATH9K_TXDESC_VMF                0x0100
 #define ATH9K_TXDESC_FRAG_IS_ON         0x0200
+#define ATH9K_TXDESC_CAB                0x0400
 
 #define ATH9K_RXDESC_INTREQ             0x0020
 
diff --git a/drivers/net/wireless/ath9k/beacon.c b/drivers/net/wireless/ath9k/beacon.c
index ee1185622ba6..fdbabc180228 100644
--- a/drivers/net/wireless/ath9k/beacon.c
+++ b/drivers/net/wireless/ath9k/beacon.c
@@ -140,56 +140,6 @@ static void ath_beacon_setup(struct ath_softc *sc,
                 ctsrate, ctsduration, series, 4, 0);
 }
 
-/* Move everything from the vap's mcast queue to the hardware cab queue.
- * Caller must hold mcasq lock and cabq lock
- * XXX MORE_DATA bit?
- */
-static void empty_mcastq_into_cabq(struct ath_hal *ah,
-        struct ath_txq *mcastq, struct ath_txq *cabq)
-{
-        struct ath_buf *bfmcast;
-
-        BUG_ON(list_empty(&mcastq->axq_q));
-
-        bfmcast = list_first_entry(&mcastq->axq_q, struct ath_buf, list);
-
-        /* link the descriptors */
-        if (!cabq->axq_link)
-                ath9k_hw_puttxbuf(ah, cabq->axq_qnum, bfmcast->bf_daddr);
-        else
-                *cabq->axq_link = bfmcast->bf_daddr;
-
-        /* append the private vap mcast list to  the cabq */
-
-        cabq->axq_depth += mcastq->axq_depth;
-        cabq->axq_totalqueued += mcastq->axq_totalqueued;
-        cabq->axq_linkbuf = mcastq->axq_linkbuf;
-        cabq->axq_link = mcastq->axq_link;
-        list_splice_tail_init(&mcastq->axq_q, &cabq->axq_q);
-        mcastq->axq_depth = 0;
-        mcastq->axq_totalqueued = 0;
-        mcastq->axq_linkbuf = NULL;
-        mcastq->axq_link = NULL;
-}
-
-/* TODO: use ieee80211_get_buffered_bc() to fetch power saved mcast frames */
-/* This is only run at DTIM. We move everything from the vap's mcast queue
- * to the hardware cab queue. Caller must hold the mcastq lock. */
-static void trigger_mcastq(struct ath_hal *ah,
-        struct ath_txq *mcastq, struct ath_txq *cabq)
-{
-        spin_lock_bh(&cabq->axq_lock);
-
-        if (!list_empty(&mcastq->axq_q))
-                empty_mcastq_into_cabq(ah, mcastq, cabq);
-
-        /* cabq is gated by beacon so it is safe to start here */
-        if (!list_empty(&cabq->axq_q))
-                ath9k_hw_txstart(ah, cabq->axq_qnum);
-
-        spin_unlock_bh(&cabq->axq_lock);
-}
-
 /*
  *  Generate beacon frame and queue cab data for a vap.
  *
@@ -200,19 +150,14 @@ static void trigger_mcastq(struct ath_hal *ah,
 */
 static struct ath_buf *ath_beacon_generate(struct ath_softc *sc, int if_id)
 {
-        struct ath_hal *ah = sc->sc_ah;
         struct ath_buf *bf;
         struct ath_vap *avp;
         struct sk_buff *skb;
         int cabq_depth;
-        int mcastq_depth;
-        int is_beacon_dtim = 0;
         struct ath_txq *cabq;
-        struct ath_txq *mcastq;
         struct ieee80211_tx_info *info;
         avp = sc->sc_vaps[if_id];
 
-        mcastq = &avp->av_mcastq;
         cabq = sc->sc_cabq;
 
         ASSERT(avp);
@@ -250,11 +195,7 @@ static struct ath_buf *ath_beacon_generate(struct ath_softc *sc, int if_id)
                                skb_end_pointer(skb) - skb->head,
                                PCI_DMA_TODEVICE);
 
-        /* TODO: convert to use ieee80211_get_buffered_bc() */
-        /* XXX: spin_lock_bh should not be used here, but sparse bitches
-         * otherwise. We should fix sparse :) */
-        spin_lock_bh(&mcastq->axq_lock);
-        mcastq_depth = avp->av_mcastq.axq_depth;
+        skb = ieee80211_get_buffered_bc(sc->hw, avp->av_if_data);
 
         /*
          * if the CABQ traffic from previous DTIM is pending and the current
@@ -268,10 +209,7 @@ static struct ath_buf *ath_beacon_generate(struct ath_softc *sc, int if_id)
         cabq_depth = cabq->axq_depth;
         spin_unlock_bh(&cabq->axq_lock);
 
-        if (avp->av_boff.bo_tim)
-                is_beacon_dtim = avp->av_boff.bo_tim[4] & 1;
-
-        if (mcastq_depth && is_beacon_dtim && cabq_depth) {
+        if (skb && cabq_depth) {
                 /*
                  * Unlock the cabq lock as ath_tx_draintxq acquires
                  * the lock again which is a common function and that
@@ -291,10 +229,11 @@ static struct ath_buf *ath_beacon_generate(struct ath_softc *sc, int if_id)
          * Enable the CAB queue before the beacon queue to
          * insure cab frames are triggered by this beacon.
          */
-        if (is_beacon_dtim)
-                trigger_mcastq(ah, mcastq, cabq);
+        while (skb) {
+                ath_tx_cabq(sc, skb);
+                skb = ieee80211_get_buffered_bc(sc->hw, avp->av_if_data);
+        }
 
-        spin_unlock_bh(&mcastq->axq_lock);
         return bf;
 }
 
@@ -426,7 +365,7 @@ int ath_beacon_alloc(struct ath_softc *sc, int if_id)
          * NB: the beacon data buffer must be 32-bit aligned;
          * we assume the wbuf routines will return us something
          * with this alignment (perhaps should assert).
-         * FIXME: Fill avp->av_boff.bo_tim,avp->av_btxctl.txpower and
+         * FIXME: Fill avp->av_btxctl.txpower and
          * avp->av_btxctl.shortPreamble
          */
         skb = ieee80211_beacon_get(sc->hw, avp->av_if_data);
diff --git a/drivers/net/wireless/ath9k/core.c b/drivers/net/wireless/ath9k/core.c
index 57645ee83efb..c262ef279ff3 100644
--- a/drivers/net/wireless/ath9k/core.c
+++ b/drivers/net/wireless/ath9k/core.c
@@ -533,9 +533,6 @@ int ath_vap_attach(struct ath_softc *sc,
         /* Set the VAP opmode */
         avp->av_opmode = opmode;
         avp->av_bslot = -1;
-        INIT_LIST_HEAD(&avp->av_mcastq.axq_q);
-        INIT_LIST_HEAD(&avp->av_mcastq.axq_acq);
-        spin_lock_init(&avp->av_mcastq.axq_lock);
 
         ath9k_hw_set_tsfadjust(sc->sc_ah, 1);
 
@@ -575,9 +572,6 @@ int ath_vap_detach(struct ath_softc *sc, int if_id)
         ath_stoprecv(sc);       /* stop recv side */
         ath_flushrecv(sc);      /* flush recv queue */
 
-        /* Reclaim any pending mcast bufs on the vap. */
-        ath_tx_draintxq(sc, &avp->av_mcastq, false);
-
         kfree(avp);
         sc->sc_vaps[if_id] = NULL;
         sc->sc_nvaps--;
diff --git a/drivers/net/wireless/ath9k/core.h b/drivers/net/wireless/ath9k/core.h
index ca7e61353547..de1d12f7c64a 100644
--- a/drivers/net/wireless/ath9k/core.h
+++ b/drivers/net/wireless/ath9k/core.h
@@ -568,6 +568,7 @@ u32 ath_txq_aggr_depth(struct ath_softc *sc, int qnum);
 void ath_notify_txq_status(struct ath_softc *sc, u16 queue_depth);
 void ath_tx_complete(struct ath_softc *sc, struct sk_buff *skb,
                      struct ath_xmit_status *tx_status, struct ath_node *an);
+void ath_tx_cabq(struct ath_softc *sc, struct sk_buff *skb);
 
 /**********************/
 /* Node / Aggregation */
@@ -713,12 +714,6 @@ struct ath_beacon_config {
         } u; /* last received beacon/probe response timestamp of this BSS. */
 };
 
-/* offsets in a beacon frame for
- * quick acess of beacon content by low-level driver */
-struct ath_beacon_offset {
-        u8 *bo_tim;     /* start of atim/dtim */
-};
-
 void ath9k_beacon_tasklet(unsigned long data);
 void ath_beacon_config(struct ath_softc *sc, int if_id);
 int ath_beaconq_setup(struct ath_hal *ah);
@@ -755,10 +750,8 @@ struct ath_vap {
         struct ieee80211_vif *av_if_data;
         enum ath9k_opmode av_opmode;    /* VAP operational mode */
         struct ath_buf *av_bcbuf;       /* beacon buffer */
-        struct ath_beacon_offset av_boff; /* dynamic update state */
         struct ath_tx_control av_btxctl;  /* txctl information for beacon */
         int av_bslot;                   /* beacon slot index */
-        struct ath_txq av_mcastq;       /* multicast transmit queue */
         struct ath_vap_config av_config;/* vap configuration parameters*/
         struct ath_rate_node *rc_node;
 };
diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index 55f48685b5ea..dca00c3a985a 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -1362,6 +1362,7 @@ static int ath_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
         }
 
         hw->flags = IEEE80211_HW_RX_INCLUDES_FCS |
+                IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING |
                 IEEE80211_HW_SIGNAL_DBM |
                 IEEE80211_HW_NOISE_DBM;
 
diff --git a/drivers/net/wireless/ath9k/xmit.c b/drivers/net/wireless/ath9k/xmit.c
index 04f94d2c8010..a18cea69904c 100644
--- a/drivers/net/wireless/ath9k/xmit.c
+++ b/drivers/net/wireless/ath9k/xmit.c
@@ -60,79 +60,6 @@ static u32 bits_per_symbol[][2] = {
 #define IS_HT_RATE(_rate)     ((_rate) & 0x80)
 
 /*
- * Insert a chain of ath_buf (descriptors) on a multicast txq
- * but do NOT start tx DMA on this queue.
- * NB: must be called with txq lock held
- */
-
-static void ath_tx_mcastqaddbuf(struct ath_softc *sc,
-                                struct ath_txq *txq,
-                                struct list_head *head)
-{
-        struct ath_hal *ah = sc->sc_ah;
-        struct ath_buf *bf;
-
-        if (list_empty(head))
-                return;
-
-        /*
-         * Insert the frame on the outbound list and
-         * pass it on to the hardware.
-         */
-        bf = list_first_entry(head, struct ath_buf, list);
-
-        /*
-         * The CAB queue is started from the SWBA handler since
-         * frames only go out on DTIM and to avoid possible races.
-         */
-        ath9k_hw_set_interrupts(ah, 0);
-
-        /*
-         * If there is anything in the mcastq, we want to set
-         * the "more data" bit in the last item in the queue to
-         * indicate that there is "more data". It makes sense to add
-         * it here since you are *always* going to have
-         * more data when adding to this queue, no matter where
-         * you call from.
-         */
-
-        if (txq->axq_depth) {
-                struct ath_buf *lbf;
-                struct ieee80211_hdr *hdr;
-
-                /*
-                 * Add the "more data flag" to the last frame
-                 */
-
-                lbf = list_entry(txq->axq_q.prev, struct ath_buf, list);
-                hdr = (struct ieee80211_hdr *)
-                        ((struct sk_buff *)(lbf->bf_mpdu))->data;
-                hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
-        }
-
-        /*
-         * Now, concat the frame onto the queue
-         */
-        list_splice_tail_init(head, &txq->axq_q);
-        txq->axq_depth++;
-        txq->axq_totalqueued++;
-        txq->axq_linkbuf = list_entry(txq->axq_q.prev, struct ath_buf, list);
-
-        DPRINTF(sc, ATH_DBG_QUEUE,
-                "%s: txq depth = %d\n", __func__, txq->axq_depth);
-        if (txq->axq_link != NULL) {
-                *txq->axq_link = bf->bf_daddr;
-                DPRINTF(sc, ATH_DBG_XMIT,
-                        "%s: link[%u](%p)=%llx (%p)\n",
-                        __func__,
-                        txq->axq_qnum, txq->axq_link,
-                        ito64(bf->bf_daddr), bf->bf_desc);
-        }
-        txq->axq_link = &(bf->bf_lastbf->bf_desc->ds_link);
-        ath9k_hw_set_interrupts(ah, sc->sc_imask);
-}
-
-/*
  * Insert a chain of ath_buf (descriptors) on a txq and
  * assume the descriptors are already chained together by caller.
  * NB: must be called with txq lock held
@@ -277,8 +204,6 @@ static int ath_tx_prepare(struct ath_softc *sc,
         __le16 fc;
         u8 *qc;
 
-        memset(txctl, 0, sizeof(struct ath_tx_control));
-
         txctl->dev = sc;
         hdr = (struct ieee80211_hdr *)skb->data;
         hdrlen = ieee80211_get_hdrlen_from_skb(skb);
@@ -329,12 +254,18 @@ static int ath_tx_prepare(struct ath_softc *sc,
 
         /* Fill qnum */
 
-        txctl->qnum = ath_get_hal_qnum(skb_get_queue_mapping(skb), sc);
-        txq = &sc->sc_txq[txctl->qnum];
+        if (unlikely(txctl->flags & ATH9K_TXDESC_CAB)) {
+                txctl->qnum = 0;
+                txq = sc->sc_cabq;
+        } else {
+                txctl->qnum = ath_get_hal_qnum(skb_get_queue_mapping(skb), sc);
+                txq = &sc->sc_txq[txctl->qnum];
+        }
         spin_lock_bh(&txq->axq_lock);
 
         /* Try to avoid running out of descriptors */
-        if (txq->axq_depth >= (ATH_TXBUF - 20)) {
+        if (txq->axq_depth >= (ATH_TXBUF - 20) &&
+            !(txctl->flags & ATH9K_TXDESC_CAB)) {
                 DPRINTF(sc, ATH_DBG_FATAL,
                         "%s: TX queue: %d is full, depth: %d\n",
                         __func__,
@@ -354,7 +285,7 @@ static int ath_tx_prepare(struct ath_softc *sc,
 
         /* Fill flags */
 
-        txctl->flags = ATH9K_TXDESC_CLRDMASK;    /* needed for crypto errors */
+        txctl->flags |= ATH9K_TXDESC_CLRDMASK; /* needed for crypto errors */
 
         if (tx_info->flags & IEEE80211_TX_CTL_NO_ACK)
                 txctl->flags |= ATH9K_TXDESC_NOACK;
@@ -1982,13 +1913,18 @@ static int ath_tx_start_dma(struct ath_softc *sc,
         struct list_head bf_head;
         struct ath_desc *ds;
         struct ath_hal *ah = sc->sc_ah;
-        struct ath_txq *txq = &sc->sc_txq[txctl->qnum];
+        struct ath_txq *txq;
         struct ath_tx_info_priv *tx_info_priv;
         struct ath_rc_series *rcs;
         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
         struct ieee80211_tx_info *tx_info =  IEEE80211_SKB_CB(skb);
         __le16 fc = hdr->frame_control;
 
+        if (unlikely(txctl->flags & ATH9K_TXDESC_CAB))
+                txq = sc->sc_cabq;
+        else
+                txq = &sc->sc_txq[txctl->qnum];
+
         /* For each sglist entry, allocate an ath_buf for DMA */
         INIT_LIST_HEAD(&bf_head);
         spin_lock_bh(&sc->sc_txbuflock);
@@ -2093,27 +2029,7 @@ static int ath_tx_start_dma(struct ath_softc *sc,
                         bf->bf_tidno = txctl->tidno;
                 }
 
-                if (is_multicast_ether_addr(hdr->addr1)) {
-                        struct ath_vap *avp = sc->sc_vaps[txctl->if_id];
-
-                        /*
-                         * When servicing one or more stations in power-save
-                         * mode (or) if there is some mcast data waiting on
-                         * mcast queue (to prevent out of order delivery of
-                         * mcast,bcast packets) multicast frames must be
-                         * buffered until after the beacon. We use the private
-                         * mcast queue for that.
-                         */
-                        /* XXX? more bit in 802.11 frame header */
-                        spin_lock_bh(&avp->av_mcastq.axq_lock);
-                        if (txctl->ps || avp->av_mcastq.axq_depth)
-                                ath_tx_mcastqaddbuf(sc,
-                                        &avp->av_mcastq, &bf_head);
-                        else
-                                ath_tx_txqaddbuf(sc, txq, &bf_head);
-                        spin_unlock_bh(&avp->av_mcastq.axq_lock);
-                } else
-                        ath_tx_txqaddbuf(sc, txq, &bf_head);
+                ath_tx_txqaddbuf(sc, txq, &bf_head);
         }
         spin_unlock_bh(&txq->axq_lock);
         return 0;
@@ -2407,6 +2323,7 @@ int ath_tx_start(struct ath_softc *sc, struct sk_buff *skb)
         struct ath_tx_control txctl;
         int error = 0;
 
+        memset(&txctl, 0, sizeof(struct ath_tx_control));
         error = ath_tx_prepare(sc, skb, &txctl);
         if (error == 0)
                 /*
@@ -2871,3 +2788,57 @@ void ath_tx_node_free(struct ath_softc *sc, struct ath_node *an)
                 }
         }
 }
+
+void ath_tx_cabq(struct ath_softc *sc, struct sk_buff *skb)
+{
+        int hdrlen, padsize;
+        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+        struct ath_tx_control txctl;
+
+        /*
+         * As a temporary workaround, assign seq# here; this will likely need
+         * to be cleaned up to work better with Beacon transmission and virtual
+         * BSSes.
+         */
+        if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
+                struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+                if (info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT)
+                        sc->seq_no += 0x10;
+                hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
+                hdr->seq_ctrl |= cpu_to_le16(sc->seq_no);
+        }
+
+        /* Add the padding after the header if this is not already done */
+        hdrlen = ieee80211_get_hdrlen_from_skb(skb);
+        if (hdrlen & 3) {
+                padsize = hdrlen % 4;
+                if (skb_headroom(skb) < padsize) {
+                        DPRINTF(sc, ATH_DBG_XMIT, "%s: TX CABQ padding "
+                                "failed\n", __func__);
+                        dev_kfree_skb_any(skb);
+                        return;
+                }
+                skb_push(skb, padsize);
+                memmove(skb->data, skb->data + padsize, hdrlen);
+        }
+
+        DPRINTF(sc, ATH_DBG_XMIT, "%s: transmitting CABQ packet, skb: %p\n",
+                __func__,
+                skb);
+
+        memset(&txctl, 0, sizeof(struct ath_tx_control));
+        txctl.flags = ATH9K_TXDESC_CAB;
+        if (ath_tx_prepare(sc, skb, &txctl) == 0) {
+                /*
+                 * Start DMA mapping.
+                 * ath_tx_start_dma() will be called either synchronously
+                 * or asynchrounsly once DMA is complete.
+                 */
+                xmit_map_sg(sc, skb, &txctl);
+        } else {
+                ath_node_put(sc, txctl.an, ATH9K_BH_STATUS_CHANGE);
+                DPRINTF(sc, ATH_DBG_XMIT, "%s: TX CABQ failed\n", __func__);
+                dev_kfree_skb_any(skb);
+        }
+}
+