Commit 680a0dab authored by Johannes Berg's avatar Johannes Berg
Browse files

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.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 2d981fdd

include/net/mac80211.h

+2 −2
Original line number Diff line number Diff line
@@ -1942,8 +1942,8 @@ enum ieee80211_hw_flags { 
 *	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-

net/mac80211/main.c

+1 −1
Original line number Diff line number Diff line
@@ -840,7 +840,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw) 


	/* 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;

net/mac80211/tx.c

+6 −0
Original line number Diff line number Diff line
@@ -2864,6 +2864,12 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb, 
			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.

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