From f6dc2095a0da8906ec65be98cfc508aaadcf5d28 Mon Sep 17 00:00:00 2001 From: Michal Kazior Date: Thu, 26 Sep 2013 10:12:22 +0300 Subject: [PATCH] ath10k: report A-MSDU subframes individually 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 Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath10k/htt_rx.c | 206 +++++++++++++------------------ drivers/net/wireless/ath/ath10k/txrx.c | 2 + 2 files changed, 85 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..617df96 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 +595,111 @@ 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 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) { + len = round_up(ieee80211_hdrlen(hdr->frame_control), 4); + len += round_up(ath10k_htt_rx_crypto_param_len(enctype), + 4); + decap_hdr += len; } - 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: + len = 0; + len += sizeof(struct rfc1042_hdr); + len += sizeof(struct amsdu_subframe_hdr); + + skb_pull(skb, sizeof(struct ethhdr)); + 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: + 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 +721,8 @@ 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 +763,8 @@ 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 +836,6 @@ 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 +910,6 @@ 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 +922,9 @@ 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); } -- 2.7.4