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Commit 5ca42627 authored by Luis R. Rodriguez's avatar Luis R. Rodriguez Committed by John W. Linville
Browse files

ath9k: avoid the copy skb->cb on every RX'd skb 



The skb->cb (control buffer, 48 bytes) is available to the skb
upon skb allocation. You can fill it up imediately after skb
allocation. ath9k was copying onto the skb->cb the data from the
processed skb for mac80211 from a stack struct ieee80211_rx_status
structure. This is unnecessary, instead use the skb->cb for the
rx status immediately after the skb becomes available and DMA
synched.

Additionally, avoid the copy of the skb->cb also for virtual wiphys
as skb_copy() will copy over the skb->cb for us as well.

Signed-off-by: default avatarLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent dbfc22df

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

+16 −22
Original line number Diff line number Diff line
@@ -283,8 +283,6 @@ static int ath_rx_prepare(struct ath_common *common, 
{

	struct ath_hw *ah = common->ah;



	memset(rx_status, 0, sizeof(struct ieee80211_rx_status));



	if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error))

		goto rx_next;
@@ -654,7 +652,7 @@ static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb) 


static void ath_rx_send_to_mac80211(struct ieee80211_hw *hw,

				    struct ath_softc *sc, struct sk_buff *skb,

				    struct ieee80211_rx_status *rx_status)

				    struct ieee80211_rx_status *rxs)

{

	struct ieee80211_hdr *hdr;
@@ -674,20 +672,15 @@ static void ath_rx_send_to_mac80211(struct ieee80211_hw *hw, 
			if (aphy == NULL)

				continue;

			nskb = skb_copy(skb, GFP_ATOMIC);

			if (nskb) {

				memcpy(IEEE80211_SKB_RXCB(nskb), rx_status,

					sizeof(*rx_status));

			if (!nskb)

				continue;

			ieee80211_rx(aphy->hw, nskb);

		}

		}

		memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));

		ieee80211_rx(sc->hw, skb);

	} else {

	} else

		/* Deliver unicast frames based on receiver address */

		memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));

		ieee80211_rx(hw, skb);

}

}



int ath_rx_tasklet(struct ath_softc *sc, int flush)

{
@@ -699,7 +692,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush) 
	struct ath_desc *ds;

	struct ath_rx_status *rx_stats;

	struct sk_buff *skb = NULL, *requeue_skb;

	struct ieee80211_rx_status rx_status;

	struct ieee80211_rx_status *rxs;

	struct ath_hw *ah = sc->sc_ah;

	struct ath_common *common = ath9k_hw_common(ah);

	/*
@@ -788,6 +781,8 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush) 
				DMA_FROM_DEVICE);



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

		rxs =  IEEE80211_SKB_RXCB(skb);



		hw = ath_get_virt_hw(sc, hdr);

		rx_stats = &ds->ds_rxstat;
@@ -806,7 +801,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush) 
			goto requeue;



		if (!ath_rx_prepare(common, hw, skb, rx_stats,

				    &rx_status, &decrypt_error))

				    rxs, &decrypt_error))

			goto requeue;



		/* Ensure we always have an skb to requeue once we are done
@@ -848,20 +843,19 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush) 
		keyix = rx_stats->rs_keyix;



		if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {

			rx_status.flag |= RX_FLAG_DECRYPTED;

			rxs->flag |= RX_FLAG_DECRYPTED;

		} else if (ieee80211_has_protected(fc)

			   && !decrypt_error && skb->len >= hdrlen + 4) {

			keyix = skb->data[hdrlen + 3] >> 6;



			if (test_bit(keyix, sc->keymap))

				rx_status.flag |= RX_FLAG_DECRYPTED;

				rxs->flag |= RX_FLAG_DECRYPTED;

		}

		if (ah->sw_mgmt_crypto &&

		    (rx_status.flag & RX_FLAG_DECRYPTED) &&

		    ieee80211_is_mgmt(fc)) {

		    (rxs->flag & RX_FLAG_DECRYPTED) &&

		    ieee80211_is_mgmt(fc))

			/* Use software decrypt for management frames. */

			rx_status.flag &= ~RX_FLAG_DECRYPTED;

		}

			rxs->flag &= ~RX_FLAG_DECRYPTED;



		/* We will now give hardware our shiny new allocated skb */

		bf->bf_mpdu = requeue_skb;
@@ -874,7 +868,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush) 
			bf->bf_mpdu = NULL;

			ath_print(common, ATH_DBG_FATAL,

				  "dma_mapping_error() on RX\n");

			ath_rx_send_to_mac80211(hw, sc, skb, &rx_status);

			ath_rx_send_to_mac80211(hw, sc, skb, rxs);

			break;

		}

		bf->bf_dmacontext = bf->bf_buf_addr;
@@ -895,7 +889,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush) 
					     SC_OP_WAIT_FOR_PSPOLL_DATA)))

			ath_rx_ps(sc, skb);



		ath_rx_send_to_mac80211(hw, sc, skb, &rx_status);

		ath_rx_send_to_mac80211(hw, sc, skb, rxs);



requeue:

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