ath9k: optimize memory allocations - improves performance and reduces ath9k RAM usage by 2 MB per device

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@25115 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 200 insertions, 0 deletions

diff --git a/package/mac80211/patches/550-ath9k_optimize_memory_allocation.patch b/package/mac80211/patches/550-ath9k_optimize_memory_allocation.patch
new file mode 100644
index 000000000..8d3d62a83
--- /dev/null
+++ b/package/mac80211/patches/550-ath9k_optimize_memory_allocation.patch
@@ -0,0 +1,200 @@
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -1291,6 +1291,11 @@ static void ath9k_stop(struct ieee80211_
+ 	} 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);
+--- a/drivers/net/wireless/ath/ath9k/recv.c
++++ b/drivers/net/wireless/ath/ath9k/recv.c
+@@ -209,11 +209,6 @@ static int ath_rx_edma_init(struct ath_s
+ 	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, in
+ 	sc->sc_flags &= ~SC_OP_RXFLUSH;
+ 	spin_lock_init(&sc->rx.rxbuflock);
+ 
++	common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 + common->cachelsz +
++			     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_c
+ 	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(struc
+ 	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,
+ 		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,
+ 		 * 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,
+ 		 * 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,
+@@ -1679,8 +1681,9 @@ int ath_rx_tasklet(struct ath_softc *sc,
+ 		if (ah->caps.rx_status_len)
+ 			skb_pull(skb, ah->caps.rx_status_len);
+ 
+-		ath9k_rx_skb_postprocess(common, skb, &rs,
+-					 rxs, decrypt_error);
++		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 */
+ 		bf->bf_mpdu = requeue_skb;
+@@ -1697,6 +1700,38 @@ int ath_rx_tasklet(struct ath_softc *sc,
+ 			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,
+ 
+ 		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);
+--- a/drivers/net/wireless/ath/ath9k/ath9k.h
++++ b/drivers/net/wireless/ath/ath9k/ath9k.h
+@@ -311,6 +311,8 @@ 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);