Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0d95521e authored by Felix Fietkau's avatar Felix Fietkau Committed by John W. Linville
Browse files

ath9k: use split rx buffers to get rid of order-1 skb allocations 



With this change, less CPU time is spent trying to look for consecutive
pages for rx skbs. This also reduces the socket memory required for IP/UDP
reassembly.
Only two buffers per frame are supported. Frames spanning more buffers
will be dropped, but the buffer size is enough to handle the required
AMSDU size.

Signed-off-by: default avatarJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: default avatarFelix Fietkau <nbd@openwrt.org>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 4d906740

drivers/net/wireless/ath/ath9k/ath9k.h

+2 −0
Original line number Diff line number Diff line
@@ -310,6 +310,8 @@ struct ath_rx { 
	struct ath_descdma rxdma;

	struct ath_buf *rx_bufptr;

	struct ath_rx_edma rx_edma[ATH9K_RX_QUEUE_MAX];



	struct sk_buff *frag;

};



int ath_startrecv(struct ath_softc *sc);

drivers/net/wireless/ath/ath9k/main.c

+5 −0
Original line number Diff line number Diff line
@@ -1294,6 +1294,11 @@ static void ath9k_stop(struct ieee80211_hw *hw) 
	} else

		sc->rx.rxlink = NULL;



	if (sc->rx.frag) {

		dev_kfree_skb_any(sc->rx.frag);

		sc->rx.frag = NULL;

	}



	/* disable HAL and put h/w to sleep */

	ath9k_hw_disable(ah);

	ath9k_hw_configpcipowersave(ah, 1, 1);

drivers/net/wireless/ath/ath9k/recv.c

+64 −24
Original line number Diff line number Diff line
@@ -209,11 +209,6 @@ static int ath_rx_edma_init(struct ath_softc *sc, int nbufs) 
	int error = 0, i;

	u32 size;





	common->rx_bufsize = roundup(IEEE80211_MAX_MPDU_LEN +

				     ah->caps.rx_status_len,

				     min(common->cachelsz, (u16)64));



	ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -

				    ah->caps.rx_status_len);
@@ -300,12 +295,12 @@ int ath_rx_init(struct ath_softc *sc, int nbufs) 
	sc->sc_flags &= ~SC_OP_RXFLUSH;

	spin_lock_init(&sc->rx.rxbuflock);



	common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +

			     sc->sc_ah->caps.rx_status_len;



	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {

		return ath_rx_edma_init(sc, nbufs);

	} else {

		common->rx_bufsize = roundup(IEEE80211_MAX_MPDU_LEN,

				min(common->cachelsz, (u16)64));



		ath_dbg(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",

			common->cachelsz, common->rx_bufsize);
@@ -815,15 +810,9 @@ static bool ath9k_rx_accept(struct ath_common *common, 
	if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len))

		return false;



	/*

	 * rs_more indicates chained descriptors which can be used

	 * to link buffers together for a sort of scatter-gather

	 * operation.

	 * reject the frame, we don't support scatter-gather yet and

	 * the frame is probably corrupt anyway

	 */

	/* Only use error bits from the last fragment */

	if (rx_stats->rs_more)

		return false;

		return true;



	/*

	 * The rx_stats->rs_status will not be set until the end of the
@@ -981,6 +970,10 @@ static int ath9k_rx_skb_preprocess(struct ath_common *common, 
	if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))

		return -EINVAL;



	/* Only use status info from the last fragment */

	if (rx_stats->rs_more)

		return 0;



	ath9k_process_rssi(common, hw, hdr, rx_stats);



	if (ath9k_process_rate(common, hw, rx_stats, rx_status))
@@ -1582,7 +1575,7 @@ div_comb_done: 
int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)

{

	struct ath_buf *bf;

	struct sk_buff *skb = NULL, *requeue_skb;

	struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;

	struct ieee80211_rx_status *rxs;

	struct ath_hw *ah = sc->sc_ah;

	struct ath_common *common = ath9k_hw_common(ah);
@@ -1633,8 +1626,17 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) 
		if (!skb)

			continue;



		hdr = (struct ieee80211_hdr *) (skb->data + rx_status_len);

		rxs =  IEEE80211_SKB_RXCB(skb);

		/*

		 * Take frame header from the first fragment and RX status from

		 * the last one.

		 */

		if (sc->rx.frag)

			hdr_skb = sc->rx.frag;

		else

			hdr_skb = skb;



		hdr = (struct ieee80211_hdr *) (hdr_skb->data + rx_status_len);

		rxs = IEEE80211_SKB_RXCB(hdr_skb);



		ath_debug_stat_rx(sc, &rs);
@@ -1643,12 +1645,12 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) 
		 * chain it back at the queue without processing it.

		 */

		if (flush)

			goto requeue;

			goto requeue_drop_frag;



		retval = ath9k_rx_skb_preprocess(common, hw, hdr, &rs,

						 rxs, &decrypt_error);

		if (retval)

			goto requeue;

			goto requeue_drop_frag;



		rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;

		if (rs.rs_tstamp > tsf_lower &&
@@ -1668,7 +1670,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) 
		 * skb and put it at the tail of the sc->rx.rxbuf list for

		 * processing. */

		if (!requeue_skb)

			goto requeue;

			goto requeue_drop_frag;



		/* Unmap the frame */

		dma_unmap_single(sc->dev, bf->bf_buf_addr,
@@ -1679,7 +1681,8 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) 
		if (ah->caps.rx_status_len)

			skb_pull(skb, ah->caps.rx_status_len);



		ath9k_rx_skb_postprocess(common, skb, &rs,

		if (!rs.rs_more)

			ath9k_rx_skb_postprocess(common, hdr_skb, &rs,

						 rxs, decrypt_error);



		/* We will now give hardware our shiny new allocated skb */
@@ -1697,6 +1700,38 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) 
			break;

		}



		if (rs.rs_more) {

			/*

			 * rs_more indicates chained descriptors which can be

			 * used to link buffers together for a sort of

			 * scatter-gather operation.

			 */

			if (sc->rx.frag) {

				/* too many fragments - cannot handle frame */

				dev_kfree_skb_any(sc->rx.frag);

				dev_kfree_skb_any(skb);

				skb = NULL;

			}

			sc->rx.frag = skb;

			goto requeue;

		}



		if (sc->rx.frag) {

			int space = skb->len - skb_tailroom(hdr_skb);



			sc->rx.frag = NULL;



			if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {

				dev_kfree_skb(skb);

				goto requeue_drop_frag;

			}



			skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),

						  skb->len);

			dev_kfree_skb_any(skb);

			skb = hdr_skb;

		}



		/*

		 * change the default rx antenna if rx diversity chooses the

		 * other antenna 3 times in a row.
@@ -1722,6 +1757,11 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) 


		ieee80211_rx(hw, skb);



requeue_drop_frag:

		if (sc->rx.frag) {

			dev_kfree_skb_any(sc->rx.frag);

			sc->rx.frag = NULL;

		}

requeue:

		if (edma) {

			list_add_tail(&bf->list, &sc->rx.rxbuf);