Add patches to fix iwl skb managment (rhbz 977040)

This commit is contained in:
Josh Boyer 2013-07-03 08:29:53 -04:00
parent c8304131bf
commit 9006cf8aee
3 changed files with 173 additions and 0 deletions

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@ -0,0 +1,97 @@
From: Eric Dumazet <edumazet@google.com>
Steinar reported reallocations of skb->head with IPv6, leading to
a warning in skb_try_coalesce()
It turns out iwl3945 has several problems :
1) skb->truesize is underestimated.
We really consume PAGE_SIZE bytes for a fragment,
not the frame length.
2) 128 bytes of initial headroom is a bit low and forces reallocations.
3) We can avoid consuming a full page for small enough frames.
Reported-by: Steinar H. Gunderson <sesse@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paul Stewart <pstew@google.com>
---
v3: use regular memcpy(skb_put(...),...)
v2: SMALL_PACKET_SIZE define
drivers/net/wireless/iwlegacy/3945.c | 31 +++++++++++++++----------
1 file changed, 19 insertions(+), 12 deletions(-)
diff --git a/drivers/net/wireless/iwlegacy/3945.c b/drivers/net/wireless/iwlegacy/3945.c
index c092033..f09e257 100644
--- a/drivers/net/wireless/iwlegacy/3945.c
+++ b/drivers/net/wireless/iwlegacy/3945.c
@@ -475,6 +475,8 @@ il3945_is_network_packet(struct il_priv *il, struct ieee80211_hdr *header)
}
}
+#define SMALL_PACKET_SIZE 256
+
static void
il3945_pass_packet_to_mac80211(struct il_priv *il, struct il_rx_buf *rxb,
struct ieee80211_rx_status *stats)
@@ -483,14 +485,13 @@ il3945_pass_packet_to_mac80211(struct il_priv *il, struct il_rx_buf *rxb,
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)IL_RX_DATA(pkt);
struct il3945_rx_frame_hdr *rx_hdr = IL_RX_HDR(pkt);
struct il3945_rx_frame_end *rx_end = IL_RX_END(pkt);
- u16 len = le16_to_cpu(rx_hdr->len);
+ u32 len = le16_to_cpu(rx_hdr->len);
struct sk_buff *skb;
__le16 fc = hdr->frame_control;
+ u32 fraglen = PAGE_SIZE << il->hw_params.rx_page_order;
/* We received data from the HW, so stop the watchdog */
- if (unlikely
- (len + IL39_RX_FRAME_SIZE >
- PAGE_SIZE << il->hw_params.rx_page_order)) {
+ if (unlikely(len + IL39_RX_FRAME_SIZE > fraglen)) {
D_DROP("Corruption detected!\n");
return;
}
@@ -506,26 +507,32 @@ il3945_pass_packet_to_mac80211(struct il_priv *il, struct il_rx_buf *rxb,
D_INFO("Woke queues - frame received on passive channel\n");
}
- skb = dev_alloc_skb(128);
+ skb = dev_alloc_skb(SMALL_PACKET_SIZE);
if (!skb) {
IL_ERR("dev_alloc_skb failed\n");
return;
}
if (!il3945_mod_params.sw_crypto)
- il_set_decrypted_flag(il, (struct ieee80211_hdr *)rxb_addr(rxb),
+ il_set_decrypted_flag(il, (struct ieee80211_hdr *)pkt,
le32_to_cpu(rx_end->status), stats);
- skb_add_rx_frag(skb, 0, rxb->page,
- (void *)rx_hdr->payload - (void *)pkt, len,
- len);
-
+ /* If frame is small enough to fit into skb->head, copy it
+ * and do not consume a full page
+ */
+ if (len <= SMALL_PACKET_SIZE) {
+ memcpy(skb_put(skb, len), rx_hdr->payload, len);
+ } else {
+ skb_add_rx_frag(skb, 0, rxb->page,
+ (void *)rx_hdr->payload - (void *)pkt, len,
+ fraglen);
+ il->alloc_rxb_page--;
+ rxb->page = NULL;
+ }
il_update_stats(il, false, fc, len);
memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
ieee80211_rx(il->hw, skb);
- il->alloc_rxb_page--;
- rxb->page = NULL;
}
#define IL_DELAY_NEXT_SCAN_AFTER_ASSOC (HZ*6)

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@ -0,0 +1,65 @@
4965 version of Eric patch "iwl3945: better skb management in rx path".
It fixes several problems :
1) skb->truesize is underestimated.
We really consume PAGE_SIZE bytes for a fragment,
not the frame length.
2) 128 bytes of initial headroom is a bit low and forces reallocations.
3) We can avoid consuming a full page for small enough frames.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
drivers/net/wireless/iwlegacy/4965-mac.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/iwlegacy/4965-mac.c b/drivers/net/wireless/iwlegacy/4965-mac.c
index d287fd2..4e5d408 100644
--- a/drivers/net/wireless/iwlegacy/4965-mac.c
+++ b/drivers/net/wireless/iwlegacy/4965-mac.c
@@ -574,9 +574,11 @@ il4965_translate_rx_status(struct il_priv *il, u32 decrypt_in)
return decrypt_out;
}
+#define SMALL_PACKET_SIZE 256
+
static void
il4965_pass_packet_to_mac80211(struct il_priv *il, struct ieee80211_hdr *hdr,
- u16 len, u32 ampdu_status, struct il_rx_buf *rxb,
+ u32 len, u32 ampdu_status, struct il_rx_buf *rxb,
struct ieee80211_rx_status *stats)
{
struct sk_buff *skb;
@@ -598,21 +600,25 @@ il4965_pass_packet_to_mac80211(struct il_priv *il, struct ieee80211_hdr *hdr,
il_set_decrypted_flag(il, hdr, ampdu_status, stats))
return;
- skb = dev_alloc_skb(128);
+ skb = dev_alloc_skb(SMALL_PACKET_SIZE);
if (!skb) {
IL_ERR("dev_alloc_skb failed\n");
return;
}
- skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb), len,
- len);
+ if (len <= SMALL_PACKET_SIZE) {
+ memcpy(skb_put(skb, len), hdr, len);
+ } else {
+ skb_add_rx_frag(skb, 0, rxb->page, (void *)hdr - rxb_addr(rxb),
+ len, PAGE_SIZE << il->hw_params.rx_page_order);
+ il->alloc_rxb_page--;
+ rxb->page = NULL;
+ }
il_update_stats(il, false, fc, len);
memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
ieee80211_rx(il->hw, skb);
- il->alloc_rxb_page--;
- rxb->page = NULL;
}
/* Called for N_RX (legacy ABG frames), or
--
1.7.11.7

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@ -771,6 +771,10 @@ Patch25054: bridge-send-query-as-soon-as-leave-is-received.patch
#rhbz 977558
Patch25055: ath3k-dont-use-stack-memory-for-DMA.patch
#rhbz 977040
Patch25056: iwl3945-better-skb-management-in-rx-path.patch
Patch25057: iwl4965-better-skb-management-in-rx-path.patch
# END OF PATCH DEFINITIONS
%endif
@ -1496,6 +1500,10 @@ ApplyPatch bridge-send-query-as-soon-as-leave-is-received.patch
#rhbz 977558
ApplyPatch ath3k-dont-use-stack-memory-for-DMA.patch
#rhbz 977040
ApplyPatch iwl3945-better-skb-management-in-rx-path.patch
ApplyPatch iwl4965-better-skb-management-in-rx-path.patch
# END OF PATCH APPLICATIONS
%endif
@ -2347,6 +2355,9 @@ fi
# '-' | |
# '-'
%changelog
* Wed Jul 03 2013 Josh Boyer <jwboyer@redhat.com>
- Add patches to fix iwl skb managment (rhbz 977040)
* Thu Jun 27 2013 Josh Boyer <jwboyer@redhat.com> - 3.9.8-100
- Linux v3.9.8