mac80211: support rx timestamps for HE rates

Signed-off-by: Felix Fietkau <nbd@nbd.name>
(cherry-picked from commit 7d8e14e44f76e18d1696565569ec50ccdce963b3)

1 files changed, 134 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/subsys/373-mac80211-support-Rx-timestamp-calculation-for-all-pr.patch b/package/kernel/mac80211/patches/subsys/373-mac80211-support-Rx-timestamp-calculation-for-all-pr.patch
new file mode 100644
index 0000000000..c432d77b2e
--- /dev/null
+++ b/package/kernel/mac80211/patches/subsys/373-mac80211-support-Rx-timestamp-calculation-for-all-pr.patch
@@ -0,0 +1,134 @@
+From: Avraham Stern <avraham.stern@intel.com>
+Date: Sun, 6 Dec 2020 14:54:45 +0200
+Subject: [PATCH] mac80211: support Rx timestamp calculation for all preamble
+ types
+
+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>
+---
+
+--- a/net/mac80211/ieee80211_i.h
++++ b/net/mac80211/ieee80211_i.h
+@@ -1600,13 +1600,8 @@ ieee80211_have_rx_timestamp(struct ieee8
+ {
+ 	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);
+--- a/net/mac80211/util.c
++++ b/net/mac80211/util.c
+@@ -3665,6 +3665,7 @@ u64 ieee80211_calculate_rx_timestamp(str
+ 	u64 ts = status->mactime;
+ 	struct rate_info ri;
+ 	u16 rate;
++	u8 n_ltf;
+ 
+ 	if (WARN_ON(!ieee80211_have_rx_timestamp(status)))
+ 		return 0;
+@@ -3675,11 +3676,58 @@ u64 ieee80211_calculate_rx_timestamp(str
+ 
+ 	/* 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;
+@@ -3687,6 +3735,23 @@ u64 ieee80211_calculate_rx_timestamp(str
+ 		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);
+@@ -3710,7 +3775,6 @@ u64 ieee80211_calculate_rx_timestamp(str
+ 		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;