mac80211: allow drivers to support S/G
If drivers want to support S/G (really just gather DMA on TX) then
we can now easily support this on the fast-xmit path since it just
needs to write to the ethernet header (and already has a check for
that being possible.)
However, disallow this on the regular TX path (which has to handle
fragmentation, software crypto, etc.) by calling skb_linearize().
Also allow the related HIGHDMA since that's not interesting to the
code in mac80211 at all anyway.
Change-Id: I22edad610596a34761e4f1ae519f5fd31e0c8898
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 2772578..a68beb8 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1941,8 +1941,8 @@
* Use the %IEEE80211_RADIOTAP_VHT_KNOWN_* values.
*
* @netdev_features: netdev features to be set in each netdev created
- * from this HW. Note only HW checksum features are currently
- * compatible with mac80211. Other feature bits will be rejected.
+ * from this HW. Note that not all features are usable with mac80211,
+ * other features will be rejected during HW registration.
*
* @uapsd_queues: This bitmap is included in (re)association frame to indicate
* for each access category if it is uAPSD trigger-enabled and delivery-
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index dde23c2..adb7ee8 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -840,7 +840,7 @@
/* Only HW csum features are currently compatible with mac80211 */
feature_whitelist = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
- NETIF_F_HW_CSUM;
+ NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_HIGHDMA;
if (WARN_ON(hw->netdev_features & ~feature_whitelist))
return -EINVAL;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 4ad6124..b8d613d 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2864,6 +2864,12 @@
goto out;
}
+ /* we cannot process non-linear frames on this path */
+ if (skb_linearize(skb)) {
+ kfree_skb(skb);
+ goto out;
+ }
+
/* the frame could be fragmented, software-encrypted, and other things
* so we cannot really handle checksum offload with it - fix it up in
* software before we handle anything else.
