From: Ben Greear <greearb@xxxxxxxxxxxxxxx>
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 <greearb@xxxxxxxxxxxxxxx>
---
: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 <linux/pci.h>
#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
--
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