On Sunday 09 January 2011 19:13:04 Jouni Malinen wrote:
> On Sat, Jan 08, 2011 at 04:36:23PM -0800, Ben Greear wrote:
> > On 01/08/2011 04:20 PM, Felix Fietkau wrote:
> > >On 2011-01-08 8:33 AM, gree...@candelatech.com wrote:
> > >>From: Ben Greear<gree...@candelatech.com>
> > >>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.
>
> As far as CPU use is concerned, 60 VIF scenario should not be the one to
> use for checking what is most efficient.. This really needs to be tested
> on something that uses a single VIF on an embedded (low-power CPU)..
>
> For the order-1 allocation issues, it would be interesting to see if
> someone could take a look at using paged skbs or multiple RX descriptors
> with shorter skbs (and copying only for the case where a long frame is
> received so that only the A-MSDU RX case would suffer from extra
> copying).
Well, here's a shot at paged rx. It'll only work when PAGE_SIZE > buf_size
(which will be true for most system, I guess)
No idea how to handle EDMA... In fact I don't have any ath9k* solution
at the moment to test ;), so you better backup your data!
---
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h
b/drivers/net/wireless/ath/ath9k/ath9k.h
index 3681caf5..b113f44 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -227,6 +227,7 @@ struct ath_buf {
an aggregate) */
struct ath_buf *bf_next; /* next subframe in the aggregate */
struct sk_buff *bf_mpdu; /* enclosing frame structure */
+ struct page *page;
void *bf_desc; /* virtual addr of desc */
dma_addr_t bf_daddr; /* physical addr of desc */
dma_addr_t bf_buf_addr; /* physical addr of data buffer, for DMA */
diff --git a/drivers/net/wireless/ath/ath9k/recv.c
b/drivers/net/wireless/ath/ath9k/recv.c
index b2497b8..acdf6ae 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -313,10 +313,13 @@ static void ath_edma_stop_recv(struct ath_softc *sc)
int ath_rx_init(struct ath_softc *sc, int nbufs)
{
struct ath_common *common = ath9k_hw_common(sc->sc_ah);
- struct sk_buff *skb;
+ struct page *page;
struct ath_buf *bf;
int error = 0;
+ if (WARN_ON(common->rx_bufsize > PAGE_SIZE))
+ return -EIO;
+
spin_lock_init(&sc->sc_pcu_lock);
sc->sc_flags &= ~SC_OP_RXFLUSH;
spin_lock_init(&sc->rx.rxbuflock);
@@ -342,27 +345,26 @@ int ath_rx_init(struct ath_softc *sc, int nbufs)
}
list_for_each_entry(bf, &sc->rx.rxbuf, list) {
- skb = ath_rxbuf_alloc(common, common->rx_bufsize,
- GFP_KERNEL);
- if (skb == NULL) {
+ page = alloc_pages(GFP_KERNEL | __GFP_ZERO, 0);
+ if (page == NULL) {
error = -ENOMEM;
goto err;
}
- bf->bf_mpdu = skb;
- bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
- common->rx_bufsize,
- DMA_FROM_DEVICE);
+ bf->bf_mpdu = NULL;
+ bf->bf_buf_addr = dma_map_page(sc->dev, page, 0,
+ PAGE_SIZE,
+ DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(sc->dev,
bf->bf_buf_addr))) {
- dev_kfree_skb_any(skb);
- bf->bf_mpdu = NULL;
+ __free_pages(page, 0);
bf->bf_buf_addr = 0;
ath_err(common,
"dma_mapping_error() on RX init\n");
error = -ENOMEM;
goto err;
}
+ bf->page = page;
}
sc->rx.rxlink = NULL;
}
@@ -378,7 +380,7 @@ void ath_rx_cleanup(struct ath_softc *sc)
{
struct ath_hw *ah = sc->sc_ah;
struct ath_common *common = ath9k_hw_common(ah);
- struct sk_buff *skb;
+ struct page *page;
struct ath_buf *bf;
if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
@@ -386,14 +388,15 @@ void ath_rx_cleanup(struct ath_softc *sc)
return;
} else {
list_for_each_entry(bf, &sc->rx.rxbuf, list) {
- skb = bf->bf_mpdu;
- if (skb) {
- dma_unmap_single(sc->dev, bf->bf_buf_addr,
- common->rx_bufsize,
- DMA_FROM_DEVICE);
- dev_kfree_skb(skb);
+ page = bf->page;
+ bf->page = NULL;
+
+ if (page) {
+ dma_unmap_page(sc->dev, bf->bf_buf_addr,
+ PAGE_SIZE,
+ DMA_FROM_DEVICE);
+ __free_pages(page, 0);
bf->bf_buf_addr = 0;
- bf->bf_mpdu = NULL;
}
}
@@ -663,12 +666,10 @@ static void ath_rx_ps(struct ath_softc *sc, struct
sk_buff *skb)
}
static void ath_rx_send_to_mac80211(struct ieee80211_hw *hw,
- struct ath_softc *sc, struct sk_buff *skb)
+ struct ath_softc *sc,
+ struct sk_buff *skb,
+ struct ieee80211_hdr *hdr)
{
- struct ieee80211_hdr *hdr;
-
- hdr = (struct ieee80211_hdr *)skb->data;
-
/* Send the frame to mac80211 */
if (is_multicast_ether_addr(hdr->addr1)) {
int i;
@@ -1037,21 +1038,20 @@ static int ath9k_rx_skb_preprocess(struct ath_common
*common,
}
static void ath9k_rx_skb_postprocess(struct ath_common *common,
- struct sk_buff *skb,
+ struct ieee80211_hdr *hdr,
+ size_t *len,
struct ath_rx_status *rx_stats,
struct ieee80211_rx_status *rxs,
bool decrypt_error)
{
struct ath_hw *ah = common->ah;
- struct ieee80211_hdr *hdr;
int hdrlen, padpos, padsize;
u8 keyix;
__le16 fc;
/* see if any padding is done by the hw and remove it */
- hdr = (struct ieee80211_hdr *) skb->data;
- hdrlen = ieee80211_get_hdrlen_from_skb(skb);
fc = hdr->frame_control;
+ hdrlen = *len >= 2 ? ieee80211_hdrlen(fc) : 0;
padpos = ath9k_cmn_padpos(hdr->frame_control);
/* The MAC header is padded to have 32-bit boundary if the
@@ -1063,9 +1063,9 @@ static void ath9k_rx_skb_postprocess(struct ath_common
*common,
* not try to remove padding from short control frames that do
* not have payload. */
padsize = padpos & 3;
- if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
- memmove(skb->data + padsize, skb->data, padpos);
- skb_pull(skb, padsize);
+ if (padsize && *len >= padpos + padsize + FCS_LEN) {
+ memmove(hdr + padsize, hdr, padpos);
+ *len -= padsize;
}
keyix = rx_stats->rs_keyix;
@@ -1074,8 +1074,10 @@ static void ath9k_rx_skb_postprocess(struct ath_common
*common,
ieee80211_has_protected(fc)) {
rxs->flag |= RX_FLAG_DECRYPTED;
} else if (ieee80211_has_protected(fc)
- && !decrypt_error && skb->len >= hdrlen + 4) {
- keyix = skb->data[hdrlen + 3] >> 6;
+ && !decrypt_error && *len >= hdrlen + 4) {
+ u8 *data = (u8 *)hdr;
+
+ keyix = data[hdrlen + 3] >> 6;
if (test_bit(keyix, common->keymap))
rxs->flag |= RX_FLAG_DECRYPTED;
@@ -1623,7 +1625,8 @@ 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;
+ struct page *requeue_page;
struct ieee80211_rx_status *rxs;
struct ath_hw *ah = sc->sc_ah;
struct ath_common *common = ath9k_hw_common(ah);
@@ -1634,6 +1637,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool
hp)
*/
struct ieee80211_hw *hw = NULL;
struct ieee80211_hdr *hdr;
+ size_t data_len;
int retval;
bool decrypt_error = false;
struct ath_rx_status rs;
@@ -1670,9 +1674,9 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool
hp)
if (!bf)
break;
- skb = bf->bf_mpdu;
+ skb = dev_alloc_skb(128);
if (!skb)
- continue;
+ goto requeue;
hdr = (struct ieee80211_hdr *) (skb->data + rx_status_len);
rxs = IEEE80211_SKB_RXCB(skb);
@@ -1704,41 +1708,40 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush,
bool hp)
/* 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);
+ requeue_page = alloc_pages(GFP_ATOMIC, 0);
/* 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)
+ if (!requeue_page) {
+ dev_kfree_skb_any(skb);
goto requeue;
+ }
/* Unmap the frame */
- dma_unmap_single(sc->dev, bf->bf_buf_addr,
- common->rx_bufsize,
- dma_type);
+ dma_unmap_page(sc->dev, bf->bf_buf_addr, PAGE_SIZE, dma_type);
- skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
- if (ah->caps.rx_status_len)
- skb_pull(skb, ah->caps.rx_status_len);
+ data_len = rs.rs_datalen;
+ ath9k_rx_skb_postprocess(common, page_address(bf->page),
+ &data_len, &rs, rxs, decrypt_error);
- ath9k_rx_skb_postprocess(common, skb, &rs,
- rxs, decrypt_error);
+ skb_add_rx_frag(skb, 0, bf->page, ah->caps.rx_status_len,
+ data_len);
/* 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);
+ bf->bf_buf_addr = dma_map_page(sc->dev, requeue_page, 0,
+ PAGE_SIZE, dma_type);
if (unlikely(dma_mapping_error(sc->dev,
bf->bf_buf_addr))) {
- dev_kfree_skb_any(requeue_skb);
- bf->bf_mpdu = NULL;
+ __free_pages(requeue_page, 0);
bf->bf_buf_addr = 0;
ath_err(common, "dma_mapping_error() on RX\n");
- ath_rx_send_to_mac80211(hw, sc, skb);
+ ath_rx_send_to_mac80211(hw, sc, skb,
+ page_address(bf->page));
break;
}
+ bf->page = requeue_page;
/*
* change the default rx antenna if rx diversity chooses the
@@ -1763,7 +1766,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool
hp)
if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)
ath_ant_comb_scan(sc, &rs);
- ath_rx_send_to_mac80211(hw, sc, skb);
+ ath_rx_send_to_mac80211(hw, sc, skb, page_address(bf->page));
requeue:
if (edma) {
_______________________________________________
ath9k-devel mailing list
ath9k-devel@lists.ath9k.org
https://lists.ath9k.org/mailman/listinfo/ath9k-devel
