[PATCH 0/5] ath10k: improve RX performance

[PATCH 0/5] ath10k: improve RX performance

[Michal Kazior]

Hi,

This patchset gives clear RX performance
improvement on AP135. Throughput is at least
doubled (300mbps -> 600mbps, UDP RX, 2x2).

This contains a workaround for
retransmission/duplication recovery.

There's a pending patch for mac80211 that will
allow proper individiual A-MSDU subframe
reporting.

Changes since RFC:
 * comments fixes (Kalle)
 * one patch extracted/split (Kalle)
 * commit message adjustments


Michal Kazior (5):
  ath10k: report A-MSDU subframes individually
  ath10k: document decap modes
  ath10k: cleanup RX decap handling
  ath10k: fix Native Wifi decap mode RX
  ath10k: align RX frames properly

 drivers/net/wireless/ath/ath10k/htt_rx.c  |  273 ++++++++++++++---------------
 drivers/net/wireless/ath/ath10k/hw.h      |    6 +-
 drivers/net/wireless/ath/ath10k/rx_desc.h |   24 ++-
 drivers/net/wireless/ath/ath10k/txrx.c    |    2 +
 4 files changed, 158 insertions(+), 147 deletions(-)

-- 
1.7.9.5

[PATCH 1/5] ath10k: report A-MSDU subframes individually

[Michal Kazior]

HW reports each A-MSDU subframe as a separate
sk_buff. It is impossible to configure it to
behave differently.

Until now ath10k was reconstructing A-MSDUs from
subframes which involved a lot of memory
operations. This proved to be a significant
contributor to degraded RX performance.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
---
 drivers/net/wireless/ath/ath10k/htt_rx.c |  204 ++++++++++++------------------
 drivers/net/wireless/ath/ath10k/txrx.c   |    2 +
 2 files changed, 83 insertions(+), 123 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index 62ea9c8..f79f815 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -41,6 +41,10 @@
 /* when under memory pressure rx ring refill may fail and needs a retry */
 #define HTT_RX_RING_REFILL_RETRY_MS 50
 
+
+static int ath10k_htt_rx_get_csum_state(struct sk_buff *skb);
+
+
 static int ath10k_htt_rx_ring_size(struct ath10k_htt *htt)
 {
 	int size;
@@ -591,136 +595,109 @@ static bool ath10k_htt_rx_hdr_is_amsdu(struct ieee80211_hdr *hdr)
 	return false;
 }
 
-static int ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
-			struct htt_rx_info *info)
+struct rfc1042_hdr {
+	u8 llc_dsap;
+	u8 llc_ssap;
+	u8 llc_ctrl;
+	u8 snap_oui[3];
+	__be16 snap_type;
+} __packed;
+
+struct amsdu_subframe_hdr {
+	u8 dst[ETH_ALEN];
+	u8 src[ETH_ALEN];
+	__be16 len;
+} __packed;
+
+static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
+				struct htt_rx_info *info)
 {
 	struct htt_rx_desc *rxd;
-	struct sk_buff *amsdu;
 	struct sk_buff *first;
-	struct ieee80211_hdr *hdr;
 	struct sk_buff *skb = info->skb;
 	enum rx_msdu_decap_format fmt;
 	enum htt_rx_mpdu_encrypt_type enctype;
+	struct ieee80211_hdr *hdr;
+	u8 hdr_buf[64];
 	unsigned int hdr_len;
-	int crypto_len;
 
 	rxd = (void *)skb->data - sizeof(*rxd);
-	fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
-			RX_MSDU_START_INFO1_DECAP_FORMAT);
 	enctype = MS(__le32_to_cpu(rxd->mpdu_start.info0),
 			RX_MPDU_START_INFO0_ENCRYPT_TYPE);
 
-	/* FIXME: No idea what assumptions are safe here. Need logs */
-	if ((fmt == RX_MSDU_DECAP_RAW && skb->next)) {
-		ath10k_htt_rx_free_msdu_chain(skb->next);
-		skb->next = NULL;
-		return -ENOTSUPP;
-	}
+	hdr = (struct ieee80211_hdr *)rxd->rx_hdr_status;
+	hdr_len = ieee80211_hdrlen(hdr->frame_control);
+	memcpy(hdr_buf, hdr, hdr_len);
+	hdr = (struct ieee80211_hdr *)hdr_buf;
 
-	/* A-MSDU max is a little less than 8K */
-	amsdu = dev_alloc_skb(8*1024);
-	if (!amsdu) {
-		ath10k_warn("A-MSDU allocation failed\n");
-		ath10k_htt_rx_free_msdu_chain(skb->next);
-		skb->next = NULL;
-		return -ENOMEM;
-	}
-
-	if (fmt >= RX_MSDU_DECAP_NATIVE_WIFI) {
-		int hdrlen;
-
-		hdr = (void *)rxd->rx_hdr_status;
-		hdrlen = ieee80211_hdrlen(hdr->frame_control);
-		memcpy(skb_put(amsdu, hdrlen), hdr, hdrlen);
-	}
+	/* FIXME: Hopefully this is a temporary measure.
+	 *
+	 * Reporting individual A-MSDU subframes means each reported frame
+	 * shares the same sequence number.
+	 *
+	 * mac80211 drops frames it recognizes as duplicates, i.e.
+	 * retransmission flag is set and sequence number matches sequence
+	 * number from a previous frame (as per IEEE 802.11-2012: 9.3.2.10
+	 * "Duplicate detection and recovery")
+	 *
+	 * To avoid frames being dropped clear retransmission flag for all
+	 * received A-MSDUs.
+	 *
+	 * Worst case: actual duplicate frames will be reported but this should
+	 * still be handled gracefully by other OSI/ISO layers. */
+	hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_RETRY);
 
 	first = skb;
 	while (skb) {
 		void *decap_hdr;
-		int decap_len = 0;
+		int decap_len;
 
 		rxd = (void *)skb->data - sizeof(*rxd);
 		fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
-				RX_MSDU_START_INFO1_DECAP_FORMAT);
+			 RX_MSDU_START_INFO1_DECAP_FORMAT);
 		decap_hdr = (void *)rxd->rx_hdr_status;
 
-		if (skb == first) {
-			/* We receive linked A-MSDU subframe skbuffs. The
-			 * first one contains the original 802.11 header (and
-			 * possible crypto param) in the RX descriptor. The
-			 * A-MSDU subframe header follows that. Each part is
-			 * aligned to 4 byte boundary. */
-
-			hdr = (void *)amsdu->data;
-			hdr_len = ieee80211_hdrlen(hdr->frame_control);
-			crypto_len = ath10k_htt_rx_crypto_param_len(enctype);
-
-			decap_hdr += roundup(hdr_len, 4);
-			decap_hdr += roundup(crypto_len, 4);
-		}
-
-		/* When fmt == RX_MSDU_DECAP_8023_SNAP_LLC:
-		 *
-		 * SNAP 802.3 consists of:
-		 * [dst:6][src:6][len:2][dsap:1][ssap:1][ctl:1][snap:5]
-		 * [data][fcs:4].
-		 *
-		 * Since this overlaps with A-MSDU header (da, sa, len)
-		 * there's nothing extra to do. */
-
-		if (fmt == RX_MSDU_DECAP_ETHERNET2_DIX) {
-			/* Ethernet2 decap inserts ethernet header in place of
-			 * A-MSDU subframe header. */
-			skb_pull(skb, 6 + 6 + 2);
-
-			/* A-MSDU subframe header length */
-			decap_len += 6 + 6 + 2;
-
-			/* Ethernet2 decap also strips the LLC/SNAP so we need
-			 * to re-insert it. The LLC/SNAP follows A-MSDU
-			 * subframe header. */
-			/* FIXME: Not all LLCs are 8 bytes long */
-			decap_len += 8;
-
-			memcpy(skb_put(amsdu, decap_len), decap_hdr, decap_len);
-		}
+		skb->ip_summed = ath10k_htt_rx_get_csum_state(skb);
 
-		if (fmt == RX_MSDU_DECAP_NATIVE_WIFI) {
-			/* Native Wifi decap inserts regular 802.11 header
-			 * in place of A-MSDU subframe header. */
-			hdr = (struct ieee80211_hdr *)skb->data;
-			skb_pull(skb, ieee80211_hdrlen(hdr->frame_control));
-
-			/* A-MSDU subframe header length */
-			decap_len += 6 + 6 + 2;
-
-			memcpy(skb_put(amsdu, decap_len), decap_hdr, decap_len);
+		/* First frame in an A-MSDU chain has more decapped data. */
+		if (skb == first) {
+			decap_hdr += round_up(ieee80211_hdrlen(hdr->frame_control), 4);
+			decap_hdr += round_up(ath10k_htt_rx_crypto_param_len(enctype), 4);
 		}
 
-		if (fmt == RX_MSDU_DECAP_RAW)
-			skb_trim(skb, skb->len - 4); /* remove FCS */
-
-		memcpy(skb_put(amsdu, skb->len), skb->data, skb->len);
-
-		/* A-MSDU subframes are padded to 4bytes
-		 * but relative to first subframe, not the whole MPDU */
-		if (skb->next && ((decap_len + skb->len) & 3)) {
-			int padlen = 4 - ((decap_len + skb->len) & 3);
-			memset(skb_put(amsdu, padlen), 0, padlen);
+		switch (fmt) {
+		case RX_MSDU_DECAP_RAW:
+			skb_trim(skb, skb->len - FCS_LEN);
+			break;
+		case RX_MSDU_DECAP_NATIVE_WIFI:
+			break;
+		case RX_MSDU_DECAP_ETHERNET2_DIX:
+			decap_len = 0;
+			decap_len += sizeof(struct rfc1042_hdr);
+			decap_len += sizeof(struct amsdu_subframe_hdr);
+
+			skb_pull(skb, sizeof(struct ethhdr));
+			memcpy(skb_push(skb, decap_len), decap_hdr, decap_len);
+			memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
+			break;
+		case RX_MSDU_DECAP_8023_SNAP_LLC:
+			memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
+			break;
 		}
 
+		info->skb = skb;
+		info->encrypt_type = enctype;
 		skb = skb->next;
-	}
-
-	info->skb = amsdu;
-	info->encrypt_type = enctype;
+		info->skb->next = NULL;
 
-	ath10k_htt_rx_free_msdu_chain(first);
+		ath10k_process_rx(htt->ar, info);
+	}
 
-	return 0;
+	/* FIXME: It might be nice to re-assemble the A-MSDU when there's a
+	 * monitor interface active for sniffing purposes. */
 }
 
-static int ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
+static void ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
 {
 	struct sk_buff *skb = info->skb;
 	struct htt_rx_desc *rxd;
@@ -742,6 +719,8 @@ static int ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
 			RX_MPDU_START_INFO0_ENCRYPT_TYPE);
 	hdr = (void *)skb->data - RX_HTT_HDR_STATUS_LEN;
 
+	skb->ip_summed = ath10k_htt_rx_get_csum_state(skb);
+
 	switch (fmt) {
 	case RX_MSDU_DECAP_RAW:
 		/* remove trailing FCS */
@@ -782,7 +761,8 @@ static int ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
 
 	info->skb = skb;
 	info->encrypt_type = enctype;
-	return 0;
+
+	ath10k_process_rx(htt->ar, info);
 }
 
 static bool ath10k_htt_rx_has_decrypt_err(struct sk_buff *skb)
@@ -854,8 +834,6 @@ static void ath10k_htt_rx_handler(struct ath10k_htt *htt,
 	int fw_desc_len;
 	u8 *fw_desc;
 	int i, j;
-	int ret;
-	int ip_summed;
 
 	memset(&info, 0, sizeof(info));
 
@@ -930,11 +908,6 @@ static void ath10k_htt_rx_handler(struct ath10k_htt *htt,
 				continue;
 			}
 
-			/* The skb is not yet processed and it may be
-			 * reallocated. Since the offload is in the original
-			 * skb extract the checksum now and assign it later */
-			ip_summed = ath10k_htt_rx_get_csum_state(msdu_head);
-
 			info.skb     = msdu_head;
 			info.fcs_err = ath10k_htt_rx_has_fcs_err(msdu_head);
 			info.signal  = ATH10K_DEFAULT_NOISE_FLOOR;
@@ -947,24 +920,9 @@ static void ath10k_htt_rx_handler(struct ath10k_htt *htt,
 			hdr = ath10k_htt_rx_skb_get_hdr(msdu_head);
 
 			if (ath10k_htt_rx_hdr_is_amsdu(hdr))
-				ret = ath10k_htt_rx_amsdu(htt, &info);
+				ath10k_htt_rx_amsdu(htt, &info);
 			else
-				ret = ath10k_htt_rx_msdu(htt, &info);
-
-			if (ret && !info.fcs_err) {
-				ath10k_warn("error processing msdus %d\n", ret);
-				dev_kfree_skb_any(info.skb);
-				continue;
-			}
-
-			if (ath10k_htt_rx_hdr_is_amsdu((void *)info.skb->data))
-				ath10k_dbg(ATH10K_DBG_HTT, "htt mpdu is amsdu\n");
-
-			info.skb->ip_summed = ip_summed;
-
-			ath10k_dbg_dump(ATH10K_DBG_HTT_DUMP, NULL, "htt mpdu: ",
-					info.skb->data, info.skb->len);
-			ath10k_process_rx(htt->ar, &info);
+				ath10k_htt_rx_msdu(htt, &info);
 		}
 	}
 
diff --git a/drivers/net/wireless/ath/ath10k/txrx.c b/drivers/net/wireless/ath/ath10k/txrx.c
index 57931d0..5ae373a 100644
--- a/drivers/net/wireless/ath/ath10k/txrx.c
+++ b/drivers/net/wireless/ath/ath10k/txrx.c
@@ -268,6 +268,8 @@ void ath10k_process_rx(struct ath10k *ar, struct htt_rx_info *info)
 		   status->vht_nss,
 		   status->freq,
 		   status->band);
+	ath10k_dbg_dump(ATH10K_DBG_HTT_DUMP, NULL, "rx skb: ",
+			info->skb->data, info->skb->len);
 
 	ieee80211_rx(ar->hw, info->skb);
 }
-- 
1.7.9.5

[PATCH 2/5] ath10k: document decap modes

[Michal Kazior]

Clarify how each decap mode works in one place.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
---
 drivers/net/wireless/ath/ath10k/rx_desc.h |   24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/rx_desc.h b/drivers/net/wireless/ath/ath10k/rx_desc.h
index bfec6c8..1c584c4 100644
--- a/drivers/net/wireless/ath/ath10k/rx_desc.h
+++ b/drivers/net/wireless/ath/ath10k/rx_desc.h
@@ -422,10 +422,30 @@ struct rx_mpdu_end {
 #define RX_MSDU_START_INFO1_IP_FRAG             (1 << 14)
 #define RX_MSDU_START_INFO1_TCP_ONLY_ACK        (1 << 15)
 
+/* The decapped header (rx_hdr_status) contains the following:
+ *  a) 802.11 header
+ *  [padding to 4 bytes]
+ *  b) HW crypto parameter
+ *     - 0 bytes for no security
+ *     - 4 bytes for WEP
+ *     - 8 bytes for TKIP, AES
+ *  [padding to 4 bytes]
+ *  c) A-MSDU subframe header (14 bytes) if appliable
+ *  d) LLC/SNAP (RFC1042, 8 bytes)
+ *
+ * In case of A-MSDU only first frame in sequence contains (a) and (b). */
 enum rx_msdu_decap_format {
-	RX_MSDU_DECAP_RAW           = 0,
-	RX_MSDU_DECAP_NATIVE_WIFI   = 1,
+	RX_MSDU_DECAP_RAW = 0,
+
+	/* Note: QoS frames are reported as non-QoS. The rx_hdr_status in
+	 * htt_rx_desc contains the original decapped 802.11 header. */
+	RX_MSDU_DECAP_NATIVE_WIFI = 1,
+
+	/* Payload contains an ethernet header (struct ethhdr). */
 	RX_MSDU_DECAP_ETHERNET2_DIX = 2,
+
+	/* Payload contains two 48-bit addresses and 2-byte length (14 bytes
+	 * total), followed by an RFC1042 header (8 bytes). */
 	RX_MSDU_DECAP_8023_SNAP_LLC = 3
 };
 
-- 
1.7.9.5

[PATCH 3/5] ath10k: cleanup RX decap handling

[Michal Kazior]

Simplify decapping code and make it easier to
understand.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
---
 drivers/net/wireless/ath/ath10k/htt_rx.c |   53 +++++++++++++++---------------
 1 file changed, 27 insertions(+), 26 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index f79f815..f8620b0 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -667,11 +667,16 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
 
 		switch (fmt) {
 		case RX_MSDU_DECAP_RAW:
+			/* remove trailing FCS */
 			skb_trim(skb, skb->len - FCS_LEN);
 			break;
 		case RX_MSDU_DECAP_NATIVE_WIFI:
+			/* nothing to do */
 			break;
 		case RX_MSDU_DECAP_ETHERNET2_DIX:
+			/* strip ethernet header and insert decapped 802.11
+			 * header, amsdu subframe header and rfc1042 header */
+
 			decap_len = 0;
 			decap_len += sizeof(struct rfc1042_hdr);
 			decap_len += sizeof(struct amsdu_subframe_hdr);
@@ -681,6 +686,7 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
 			memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
 			break;
 		case RX_MSDU_DECAP_8023_SNAP_LLC:
+			/* insert decapped 802.11 header making a singly A-MSDU */
 			memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
 			break;
 		}
@@ -704,6 +710,8 @@ static void ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
 	struct ieee80211_hdr *hdr;
 	enum rx_msdu_decap_format fmt;
 	enum htt_rx_mpdu_encrypt_type enctype;
+	int hdr_len;
+	void *rfc1042;
 
 	/* This shouldn't happen. If it does than it may be a FW bug. */
 	if (skb->next) {
@@ -717,46 +725,39 @@ static void ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
 			RX_MSDU_START_INFO1_DECAP_FORMAT);
 	enctype = MS(__le32_to_cpu(rxd->mpdu_start.info0),
 			RX_MPDU_START_INFO0_ENCRYPT_TYPE);
-	hdr = (void *)skb->data - RX_HTT_HDR_STATUS_LEN;
+	hdr = (struct ieee80211_hdr *)rxd->rx_hdr_status;
+	hdr_len = ieee80211_hdrlen(hdr->frame_control);
 
 	skb->ip_summed = ath10k_htt_rx_get_csum_state(skb);
 
 	switch (fmt) {
 	case RX_MSDU_DECAP_RAW:
 		/* remove trailing FCS */
-		skb_trim(skb, skb->len - 4);
+		skb_trim(skb, skb->len - FCS_LEN);
 		break;
 	case RX_MSDU_DECAP_NATIVE_WIFI:
 		/* nothing to do here */
 		break;
 	case RX_MSDU_DECAP_ETHERNET2_DIX:
-		/* macaddr[6] + macaddr[6] + ethertype[2] */
-		skb_pull(skb, 6 + 6 + 2);
-		break;
-	case RX_MSDU_DECAP_8023_SNAP_LLC:
-		/* macaddr[6] + macaddr[6] + len[2] */
-		/* we don't need this for non-A-MSDU */
-		skb_pull(skb, 6 + 6 + 2);
-		break;
-	}
-
-	if (fmt == RX_MSDU_DECAP_ETHERNET2_DIX) {
-		void *llc;
-		int llclen;
+		/* strip ethernet header and insert decapped 802.11 header and
+		 * rfc1042 header */
 
-		llclen = 8;
-		llc  = hdr;
-		llc += roundup(ieee80211_hdrlen(hdr->frame_control), 4);
-		llc += roundup(ath10k_htt_rx_crypto_param_len(enctype), 4);
+		rfc1042 = hdr;
+		rfc1042 += roundup(hdr_len, 4);
+		rfc1042 += roundup(ath10k_htt_rx_crypto_param_len(enctype), 4);
 
-		skb_push(skb, llclen);
-		memcpy(skb->data, llc, llclen);
-	}
+		skb_pull(skb, sizeof(struct ethhdr));
+		memcpy(skb_push(skb, sizeof(struct rfc1042_hdr)),
+		       rfc1042, sizeof(struct rfc1042_hdr));
+		memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
+		break;
+	case RX_MSDU_DECAP_8023_SNAP_LLC:
+		/* remove A-MSDU subframe header and insert
+		 * decapped 802.11 header. rfc1042 header is already there */
 
-	if (fmt >= RX_MSDU_DECAP_ETHERNET2_DIX) {
-		int len = ieee80211_hdrlen(hdr->frame_control);
-		skb_push(skb, len);
-		memcpy(skb->data, hdr, len);
+		skb_pull(skb, sizeof(struct amsdu_subframe_hdr));
+		memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
+		break;
 	}
 
 	info->skb = skb;
-- 
1.7.9.5

[PATCH 4/5] ath10k: fix Native Wifi decap mode RX

[Michal Kazior]

NWifi decap mode always reports 802.11 Data
Frames, even when QoS Data Frames are actually
received.

This made mac80211 not report frame priority
properly (since there was no QoS Control field).

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
---
 drivers/net/wireless/ath/ath10k/htt_rx.c |   32 +++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index f8620b0..c119057 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -618,7 +618,7 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
 	enum rx_msdu_decap_format fmt;
 	enum htt_rx_mpdu_encrypt_type enctype;
 	struct ieee80211_hdr *hdr;
-	u8 hdr_buf[64];
+	u8 hdr_buf[64], addr[ETH_ALEN], *qos;
 	unsigned int hdr_len;
 
 	rxd = (void *)skb->data - sizeof(*rxd);
@@ -671,7 +671,25 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
 			skb_trim(skb, skb->len - FCS_LEN);
 			break;
 		case RX_MSDU_DECAP_NATIVE_WIFI:
-			/* nothing to do */
+			/* pull decapped header and copy DA */
+			hdr = (struct ieee80211_hdr *)skb->data;
+			hdr_len = ieee80211_hdrlen(hdr->frame_control);
+			memcpy(addr, ieee80211_get_DA(hdr), ETH_ALEN);
+			skb_pull(skb, hdr_len);
+
+			/* push original 802.11 header */
+			hdr = (struct ieee80211_hdr *)hdr_buf;
+			hdr_len = ieee80211_hdrlen(hdr->frame_control);
+			memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
+
+			/* original A-MSDU header has the bit set but we're
+			 * not including A-MSDU subframe header */
+			hdr = (struct ieee80211_hdr *)skb->data;
+			qos = ieee80211_get_qos_ctl(hdr);
+			qos[0] &= ~IEEE80211_QOS_CTL_A_MSDU_PRESENT;
+
+			/* original 802.11 header has a different DA */
+			memcpy(ieee80211_get_DA(hdr), addr, ETH_ALEN);
 			break;
 		case RX_MSDU_DECAP_ETHERNET2_DIX:
 			/* strip ethernet header and insert decapped 802.11
@@ -736,7 +754,15 @@ static void ath10k_htt_rx_msdu(struct ath10k_htt *htt, struct htt_rx_info *info)
 		skb_trim(skb, skb->len - FCS_LEN);
 		break;
 	case RX_MSDU_DECAP_NATIVE_WIFI:
-		/* nothing to do here */
+		/* Pull decapped header */
+		hdr = (struct ieee80211_hdr *)skb->data;
+		hdr_len = ieee80211_hdrlen(hdr->frame_control);
+		skb_pull(skb, hdr_len);
+
+		/* Push original header */
+		hdr = (struct ieee80211_hdr *)rxd->rx_hdr_status;
+		hdr_len = ieee80211_hdrlen(hdr->frame_control);
+		memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
 		break;
 	case RX_MSDU_DECAP_ETHERNET2_DIX:
 		/* strip ethernet header and insert decapped 802.11 header and
-- 
1.7.9.5

[PATCH 5/5] ath10k: align RX frames properly

[Michal Kazior]

Ethernet-like decapping mode leaves IP protocol
frame not aligned to 4-byte boundaries. This leads
to re-aligning in mac80211 which in turn leads to
poor CPU cache behaviour on some machines.

Since HW doesn't allow to change payload offset
properly the solution is to force HW to decap in
Native Wifi mode which always has 24-bytes long
802.11 header (even for QoS frames). This means IP
frame is properly aligned in this decap mode.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
---
 drivers/net/wireless/ath/ath10k/hw.h |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/hw.h b/drivers/net/wireless/ath/ath10k/hw.h
index 643f0c9..8c1be768 100644
--- a/drivers/net/wireless/ath/ath10k/hw.h
+++ b/drivers/net/wireless/ath/ath10k/hw.h
@@ -74,7 +74,11 @@ enum ath10k_mcast2ucast_mode {
 #define TARGET_RX_CHAIN_MASK			(BIT(0) | BIT(1) | BIT(2))
 #define TARGET_RX_TIMEOUT_LO_PRI		100
 #define TARGET_RX_TIMEOUT_HI_PRI		40
-#define TARGET_RX_DECAP_MODE			ATH10K_HW_TXRX_ETHERNET
+
+/* Native Wifi decap mode is used to align IP frames to 4-byte boundaries and
+ * avoid a very expensive re-alignment in mac80211. */
+#define TARGET_RX_DECAP_MODE			ATH10K_HW_TXRX_NATIVE_WIFI
+
 #define TARGET_SCAN_MAX_PENDING_REQS		4
 #define TARGET_BMISS_OFFLOAD_MAX_VDEV		3
 #define TARGET_ROAM_OFFLOAD_MAX_VDEV		3
-- 
1.7.9.5

Re: [PATCH 0/5] ath10k: improve RX performance

[Kalle Valo]

Michal Kazior <michal.kazior@tieto.com> writes:

> This patchset gives clear RX performance
> improvement on AP135. Throughput is at least
> doubled (300mbps -> 600mbps, UDP RX, 2x2).
>
> This contains a workaround for
> retransmission/duplication recovery.
>
> There's a pending patch for mac80211 that will
> allow proper individiual A-MSDU subframe
> reporting.
>
> Changes since RFC:
>  * comments fixes (Kalle)
>  * one patch extracted/split (Kalle)
>  * commit message adjustments
>
>
> Michal Kazior (5):
>   ath10k: report A-MSDU subframes individually
>   ath10k: document decap modes
>   ath10k: cleanup RX decap handling
>   ath10k: fix Native Wifi decap mode RX
>   ath10k: align RX frames properly

All five applies, thanks.

There were few long lines, I fixed those myself. Can you please double
check that I didn't break anything?

Kalle

For patch 1 I did:

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index e30b95c..c5f1800 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -650,7 +650,7 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
 	first = skb;
 	while (skb) {
 		void *decap_hdr;
-		int decap_len;
+		int len;
 
 		rxd = (void *)skb->data - sizeof(*rxd);
 		fmt = MS(__le32_to_cpu(rxd->msdu_start.info1),
@@ -661,8 +661,10 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
 
 		/* First frame in an A-MSDU chain has more decapped data. */
 		if (skb == first) {
-			decap_hdr += round_up(ieee80211_hdrlen(hdr->frame_control), 4);
-			decap_hdr += round_up(ath10k_htt_rx_crypto_param_len(enctype), 4);
+			len = round_up(ieee80211_hdrlen(hdr->frame_control), 4);
+			len += round_up(ath10k_htt_rx_crypto_param_len(enctype),
+					4);
+			decap_hdr += len;
 		}
 
 		switch (fmt) {
@@ -672,12 +674,12 @@ static void ath10k_htt_rx_amsdu(struct ath10k_htt *htt,
 		case RX_MSDU_DECAP_NATIVE_WIFI:
 			break;
 		case RX_MSDU_DECAP_ETHERNET2_DIX:
-			decap_len = 0;
-			decap_len += sizeof(struct rfc1042_hdr);
-			decap_len += sizeof(struct amsdu_subframe_hdr);
+			len = 0;
+			len += sizeof(struct rfc1042_hdr);
+			len += sizeof(struct amsdu_subframe_hdr);
 
 			skb_pull(skb, sizeof(struct ethhdr));
-			memcpy(skb_push(skb, decap_len), decap_hdr, decap_len);
+			memcpy(skb_push(skb, len), decap_hdr, len);
 			memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
 			break;
 		case RX_MSDU_DECAP_8023_SNAP_LLC:

And for patch 3:

diff --cc drivers/net/wireless/ath/ath10k/htt_rx.c
index c5f1800,c94ced8..0000000
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@@ -672,14 -671,18 +673,18 @@@ static void ath10k_htt_rx_amsdu(struct 
  			skb_trim(skb, skb->len - FCS_LEN);
  			break;
  		case RX_MSDU_DECAP_NATIVE_WIFI:
+ 			/* nothing to do */
  			break;
  		case RX_MSDU_DECAP_ETHERNET2_DIX:
+ 			/* strip ethernet header and insert decapped 802.11
+ 			 * header, amsdu subframe header and rfc1042 header */
+ 
 -			decap_len = 0;
 -			decap_len += sizeof(struct rfc1042_hdr);
 -			decap_len += sizeof(struct amsdu_subframe_hdr);
 +			len = 0;
 +			len += sizeof(struct rfc1042_hdr);
 +			len += sizeof(struct amsdu_subframe_hdr);
  
  			skb_pull(skb, sizeof(struct ethhdr));
 -			memcpy(skb_push(skb, decap_len), decap_hdr, decap_len);
 +			memcpy(skb_push(skb, len), decap_hdr, len);
  			memcpy(skb_push(skb, hdr_len), hdr, hdr_len);
  			break;
  		case RX_MSDU_DECAP_8023_SNAP_LLC:

Re: [PATCH 0/5] ath10k: improve RX performance

[Michal Kazior]

On 26 September 2013 09:21, Kalle Valo <kvalo@qca.qualcomm.com> wrote:
> Michal Kazior <michal.kazior@tieto.com> writes:
>
>> This patchset gives clear RX performance
>> improvement on AP135. Throughput is at least
>> doubled (300mbps -> 600mbps, UDP RX, 2x2).
>>
>> This contains a workaround for
>> retransmission/duplication recovery.
>>
>> There's a pending patch for mac80211 that will
>> allow proper individiual A-MSDU subframe
>> reporting.
>>
>> Changes since RFC:
>>  * comments fixes (Kalle)
>>  * one patch extracted/split (Kalle)
>>  * commit message adjustments
>>
>>
>> Michal Kazior (5):
>>   ath10k: report A-MSDU subframes individually
>>   ath10k: document decap modes
>>   ath10k: cleanup RX decap handling
>>   ath10k: fix Native Wifi decap mode RX
>>   ath10k: align RX frames properly
>
> All five applies, thanks.
>
> There were few long lines, I fixed those myself. Can you please double
> check that I didn't break anything?
>
> Kalle
>
> For patch 1 I did:
>
> (...)

Looks good. Thanks!


Michał.