[PATCH AUTOSEL 5.4 120/130] mac80211: support Rx timestamp calculation for all preamble types

Sasha Levin
2020-12-23T02:55:09Z

From: Avraham Stern <avraham.stern@intel.com>

[ Upstream commit da3882331a55ba8c8eda0cfc077ad3b88c257e22 ]

Add support for calculating the Rx timestamp for HE frames.
Since now all frame types are supported, allow setting the Rx
timestamp regardless of the frame type.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201206145305.4786559af475.Ia54486bb0a12e5351f9d5c60ef6fcda7c9e7141c@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/ieee80211_i.h | 9 ++----
net/mac80211/util.c | 66 +++++++++++++++++++++++++++++++++++++-
2 files changed, 67 insertions(+), 8 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 05406e9c05b32..7ad21d041f063 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1561,13 +1561,8 @@ ieee80211_have_rx_timestamp(struct ieee80211_rx_status *status)
{
WARN_ON_ONCE(status->flag & RX_FLAG_MACTIME_START &&
status->flag & RX_FLAG_MACTIME_END);
- if (status->flag & (RX_FLAG_MACTIME_START | RX_FLAG_MACTIME_END))
- return true;
- /* can't handle non-legacy preamble yet */
- if (status->flag & RX_FLAG_MACTIME_PLCP_START &&
- status->encoding == RX_ENC_LEGACY)
- return true;
- return false;
+ return !!(status->flag & (RX_FLAG_MACTIME_START | RX_FLAG_MACTIME_END |
+ RX_FLAG_MACTIME_PLCP_START));
}

void ieee80211_vif_inc_num_mcast(struct ieee80211_sub_if_data *sdata);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index decd46b383938..9f05336509210 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -3238,6 +3238,7 @@ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,
u64 ts = status->mactime;
struct rate_info ri;
u16 rate;
+ u8 n_ltf;

if (WARN_ON(!ieee80211_have_rx_timestamp(status)))
return 0;
@@ -3248,11 +3249,58 @@ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,

/* Fill cfg80211 rate info */
switch (status->encoding) {
+ case RX_ENC_HE:
+ ri.flags |= RATE_INFO_FLAGS_HE_MCS;
+ ri.mcs = status->rate_idx;
+ ri.nss = status->nss;
+ ri.he_ru_alloc = status->he_ru;
+ if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
+ ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
+
+ /*
+ * See P802.11ax_D6.0, section 27.3.4 for
+ * VHT PPDU format.
+ */
+ if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
+ mpdu_offset += 2;
+ ts += 36;
+
+ /*
+ * TODO:
+ * For HE MU PPDU, add the HE-SIG-B.
+ * For HE ER PPDU, add 8us for the HE-SIG-A.
+ * For HE TB PPDU, add 4us for the HE-STF.
+ * Add the HE-LTF durations - variable.
+ */
+ }
+
+ break;
case RX_ENC_HT:
ri.mcs = status->rate_idx;
ri.flags |= RATE_INFO_FLAGS_MCS;
if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
+
+ /*
+ * See P802.11REVmd_D3.0, section 19.3.2 for
+ * HT PPDU format.
+ */
+ if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
+ mpdu_offset += 2;
+ if (status->enc_flags & RX_ENC_FLAG_HT_GF)
+ ts += 24;
+ else
+ ts += 32;
+
+ /*
+ * Add Data HT-LTFs per streams
+ * TODO: add Extension HT-LTFs, 4us per LTF
+ */
+ n_ltf = ((ri.mcs >> 3) & 3) + 1;
+ n_ltf = n_ltf == 3 ? 4 : n_ltf;
+ ts += n_ltf * 4;
+ }
+
break;
case RX_ENC_VHT:
ri.flags |= RATE_INFO_FLAGS_VHT_MCS;
@@ -3260,6 +3308,23 @@ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,
ri.nss = status->nss;
if (status->enc_flags & RX_ENC_FLAG_SHORT_GI)
ri.flags |= RATE_INFO_FLAGS_SHORT_GI;
+
+ /*
+ * See P802.11REVmd_D3.0, section 21.3.2 for
+ * VHT PPDU format.
+ */
+ if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
+ mpdu_offset += 2;
+ ts += 36;
+
+ /*
+ * Add VHT-LTFs per streams
+ */
+ n_ltf = (ri.nss != 1) && (ri.nss % 2) ?
+ ri.nss + 1 : ri.nss;
+ ts += 4 * n_ltf;
+ }
+
break;
default:
WARN_ON(1);
@@ -3283,7 +3348,6 @@ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local,
ri.legacy = DIV_ROUND_UP(bitrate, (1 << shift));

if (status->flag & RX_FLAG_MACTIME_PLCP_START) {
- /* TODO: handle HT/VHT preambles */
if (status->band == NL80211_BAND_5GHZ) {
ts += 20 << shift;
mpdu_offset += 2;
--
2.27.0