mac80211: add fast-rx path
The regular RX path has a lot of code, but with a few
assumptions on the hardware it's possible to reduce the
amount of code significantly. Currently the assumptions
on the driver are the following:
* hardware/driver reordering buffer (if supporting aggregation)
* hardware/driver decryption & PN checking (if using encryption)
* hardware/driver did de-duplication
* hardware/driver did A-MSDU deaggregation
* AP_LINK_PS is used (in AP mode)
* no client powersave handling in mac80211 (in client mode)
of which some are actually checked per packet:
* de-duplication
* PN checking
* decryption
and additionally packets must
* not be A-MSDU (have been deaggregated by driver/device)
* be data packets
* not be fragmented
* be unicast
* have RFC 1042 header
Additionally dynamically we assume:
* no encryption or CCMP/GCMP, TKIP/WEP/other not allowed
* station must be authorized
* 4-addr format not enabled
Some data needed for the RX path is cached in a new per-station
"fast_rx" structure, so that we only need to look at this and
the packet, no other memory when processing packets on the fast
RX path.
After doing the above per-packet checks, the data path collapses
down to a pretty simple conversion function taking advantage of
the data cached in the small fast_rx struct.
This should speed up the RX processing, and will make it easier
to reason about parallelizing RX (for which statistics will need
to be per-CPU still.)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index bf9706c..113bfc4 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -638,6 +638,16 @@
return (seq_ctrl & cpu_to_le16(IEEE80211_SCTL_FRAG)) == 0;
}
+/**
+ * ieee80211_is_frag - check if a frame is a fragment
+ * @hdr: 802.11 header of the frame
+ */
+static inline bool ieee80211_is_frag(struct ieee80211_hdr *hdr)
+{
+ return ieee80211_has_morefrags(hdr->frame_control) ||
+ hdr->seq_ctrl & cpu_to_le16(IEEE80211_SCTL_FRAG);
+}
+
struct ieee80211s_hdr {
u8 flags;
u8 ttl;