Return-path: Received: from mail.candelatech.com ([208.74.158.172]:38198 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753000Ab1AHPde (ORCPT ); Sat, 8 Jan 2011 10:33:34 -0500 From: greearb@candelatech.com To: linux-wireless@vger.kernel.org Cc: ath9k-devel@venema.h4ckr.net, Ben Greear Subject: [PATCH] ath9k: Implement rx copy-break. Date: Sat, 8 Jan 2011 07:33:20 -0800 Message-Id: <1294500800-29191-1-git-send-email-greearb@candelatech.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Ben Greear This saves us constantly allocating large, multi-page skbs. It should fix the order-1 allocation errors reported, and in a 60-vif scenario, this significantly decreases CPU utilization, and latency, and increases bandwidth. Signed-off-by: Ben Greear --- :100644 100644 b2497b8... ea2f67c... M drivers/net/wireless/ath/ath9k/recv.c drivers/net/wireless/ath/ath9k/recv.c | 92 ++++++++++++++++++++++----------- 1 files changed, 61 insertions(+), 31 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c index b2497b8..ea2f67c 100644 --- a/drivers/net/wireless/ath/ath9k/recv.c +++ b/drivers/net/wireless/ath/ath9k/recv.c @@ -16,6 +16,7 @@ #include "ath9k.h" #include "ar9003_mac.h" +#include #define SKB_CB_ATHBUF(__skb) (*((struct ath_buf **)__skb->cb)) @@ -1623,7 +1624,7 @@ 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 = NULL; struct ieee80211_rx_status *rxs; struct ath_hw *ah = sc->sc_ah; struct ath_common *common = ath9k_hw_common(ah); @@ -1634,7 +1635,8 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) */ struct ieee80211_hw *hw = NULL; struct ieee80211_hdr *hdr; - int retval; + int retval, len; + bool use_copybreak = true; bool decrypt_error = false; struct ath_rx_status rs; enum ath9k_rx_qtype qtype; @@ -1702,42 +1704,70 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) unlikely(tsf_lower - rs.rs_tstamp > 0x10000000)) rxs->mactime += 0x100000000ULL; - /* Ensure we always have an skb to requeue once we are done - * processing the current buffer's skb */ - requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC); - - /* If there is no memory we ignore the current RX'd frame, - * tell hardware it can give us a new frame using the old - * skb and put it at the tail of the sc->rx.rxbuf list for - * processing. */ - if (!requeue_skb) - goto requeue; - - /* Unmap the frame */ - dma_unmap_single(sc->dev, bf->bf_buf_addr, - common->rx_bufsize, - dma_type); + len = rs.rs_datalen + ah->caps.rx_status_len; + if (use_copybreak) { + skb = netdev_alloc_skb(NULL, len); + if (!skb) { + skb = bf->bf_mpdu; + use_copybreak = false; + goto non_copybreak; + } + } else { +non_copybreak: + /* Ensure we always have an skb to requeue once we are + * done processing the current buffer's skb */ + requeue_skb = ath_rxbuf_alloc(common, + common->rx_bufsize, + GFP_ATOMIC); + + /* If there is no memory we ignore the current RX'd + * frame, tell hardware it can give us a new frame + * using the old skb and put it at the tail of the + * sc->rx.rxbuf list for processing. */ + if (!requeue_skb) + goto requeue; + + /* Unmap the frame */ + dma_unmap_single(sc->dev, bf->bf_buf_addr, + common->rx_bufsize, + dma_type); + } - skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len); + skb_put(skb, len); if (ah->caps.rx_status_len) skb_pull(skb, ah->caps.rx_status_len); + if (use_copybreak) { + struct pci_dev *pdev = to_pci_dev(sc->dev); + pci_dma_sync_single_for_cpu(pdev, bf->bf_buf_addr, + len, PCI_DMA_FROMDEVICE); + skb_copy_from_linear_data(bf->bf_mpdu, skb->data, len); + pci_dma_sync_single_for_device(pdev, bf->bf_buf_addr, + len, PCI_DMA_FROMDEVICE); + memcpy(skb->cb, bf->bf_mpdu->cb, sizeof(skb->cb)); + rxs = IEEE80211_SKB_RXCB(skb); + } + ath9k_rx_skb_postprocess(common, skb, &rs, rxs, decrypt_error); - /* We will now give hardware our shiny new allocated skb */ - bf->bf_mpdu = requeue_skb; - bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data, - common->rx_bufsize, - dma_type); - if (unlikely(dma_mapping_error(sc->dev, - bf->bf_buf_addr))) { - dev_kfree_skb_any(requeue_skb); - bf->bf_mpdu = NULL; - bf->bf_buf_addr = 0; - ath_err(common, "dma_mapping_error() on RX\n"); - ath_rx_send_to_mac80211(hw, sc, skb); - break; + if (!use_copybreak) { + /* We will now give hardware our shiny new allocated + * skb */ + bf->bf_mpdu = requeue_skb; + bf->bf_buf_addr = dma_map_single(sc->dev, + requeue_skb->data, + common->rx_bufsize, + dma_type); + if (unlikely(dma_mapping_error(sc->dev, + bf->bf_buf_addr))) { + dev_kfree_skb_any(requeue_skb); + bf->bf_mpdu = NULL; + bf->bf_buf_addr = 0; + ath_err(common, "dma_mapping_error() on RX\n"); + ath_rx_send_to_mac80211(hw, sc, skb); + break; + } } /* -- 1.7.2.3