wifi: iwlwifi: mvm: report hardware timestamps in RX/TX status

For TM/FTM frames, report the hardware timestamps reported by the
fw as part of the RX/TX status. Since the fw reports the timestamps
in a dedicated notification (and not as part of the RX/TX status),
hold the frame until the fw timestamps notification is received.
Timestamping is enabled when a station is connected and disabled
when disconnected. For AP interface, only the first station will
have timestamping enabled since the fw only supports timestamping
for one peer.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230320122330.e0392d498101.I9bf12c8ecfb3f17253a13dc48a48647ddd6e7855@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 174 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/time-sync.c b/drivers/net/wireless/intel/iwlwifi/mvm/time-sync.c
new file mode 100644
index 000000000000..b42e58e5ff24
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/time-sync.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (C) 2022 Intel Corporation
+ */
+
+#include "mvm.h"
+#include "time-sync.h"
+#include <linux/ieee80211.h>
+
+void iwl_mvm_init_time_sync(struct iwl_time_sync_data *data)
+{
+	skb_queue_head_init(&data->frame_list);
+}
+
+static bool iwl_mvm_is_skb_match(struct sk_buff *skb, u8 *addr, u8 dialog_token)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+	u8 skb_dialog_token;
+
+	if (ieee80211_is_timing_measurement(skb))
+		skb_dialog_token = mgmt->u.action.u.wnm_timing_msr.dialog_token;
+	else
+		skb_dialog_token = mgmt->u.action.u.ftm.dialog_token;
+
+	if ((ether_addr_equal(mgmt->sa, addr) ||
+	     ether_addr_equal(mgmt->da, addr)) &&
+	    skb_dialog_token == dialog_token)
+		return true;
+
+	return false;
+}
+
+static struct sk_buff *iwl_mvm_time_sync_find_skb(struct iwl_mvm *mvm, u8 *addr,
+						  u8 dialog_token)
+{
+	struct sk_buff *skb;
+
+	/* The queue is expected to have only one SKB. If there are other SKBs
+	 * in the queue, they did not get a time sync notification and are
+	 * probably obsolete by now, so drop them.
+	 */
+	while ((skb = skb_dequeue(&mvm->time_sync.frame_list))) {
+		if (iwl_mvm_is_skb_match(skb, addr, dialog_token))
+			break;
+
+		kfree_skb(skb);
+		skb = NULL;
+	}
+
+	return skb;
+}
+
+static u64 iwl_mvm_get_64_bit(__le32 high, __le32 low)
+{
+	return ((u64)le32_to_cpu(high) << 32) | le32_to_cpu(low);
+}
+
+void iwl_mvm_time_sync_msmt_event(struct iwl_mvm *mvm,
+				  struct iwl_rx_cmd_buffer *rxb)
+{
+	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	struct iwl_time_msmt_notify *notif = (void *)pkt->data;
+	struct ieee80211_rx_status *rx_status;
+	struct skb_shared_hwtstamps *shwt;
+	u64 ts_10ns;
+	struct sk_buff *skb =
+		iwl_mvm_time_sync_find_skb(mvm, notif->peer_addr,
+					   le32_to_cpu(notif->dialog_token));
+
+	if (!skb) {
+		IWL_DEBUG_INFO(mvm, "Time sync event but no pending skb\n");
+		return;
+	}
+
+	ts_10ns = iwl_mvm_get_64_bit(notif->t3_hi, notif->t3_lo);
+	rx_status = IEEE80211_SKB_RXCB(skb);
+	rx_status->ack_tx_hwtstamp = ktime_set(0, ts_10ns * 10);
+
+	ts_10ns = iwl_mvm_get_64_bit(notif->t2_hi, notif->t2_lo);
+	shwt = skb_hwtstamps(skb);
+	shwt->hwtstamp = ktime_set(0, ts_10ns * 10);
+
+	IWL_DEBUG_INFO(mvm,
+		       "Time sync: RX event - report frame t2=%llu t3=%llu\n",
+		       ktime_to_ns(shwt->hwtstamp),
+		       ktime_to_ns(rx_status->ack_tx_hwtstamp));
+	ieee80211_rx_napi(mvm->hw, NULL, skb, NULL);
+}
+
+void iwl_mvm_time_sync_msmt_confirm_event(struct iwl_mvm *mvm,
+					  struct iwl_rx_cmd_buffer *rxb)
+{
+	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	struct iwl_time_msmt_cfm_notify *notif = (void *)pkt->data;
+	struct ieee80211_tx_status status = {};
+	struct skb_shared_hwtstamps *shwt;
+	u64 ts_10ns;
+
+	status.skb =
+		iwl_mvm_time_sync_find_skb(mvm, notif->peer_addr,
+					   le32_to_cpu(notif->dialog_token));
+
+	if (!status.skb) {
+		IWL_DEBUG_INFO(mvm, "Time sync confirm but no pending skb\n");
+		return;
+	}
+
+	status.info = IEEE80211_SKB_CB(status.skb);
+
+	ts_10ns = iwl_mvm_get_64_bit(notif->t4_hi, notif->t4_lo);
+	status.ack_hwtstamp = ktime_set(0, ts_10ns * 10);
+
+	ts_10ns = iwl_mvm_get_64_bit(notif->t1_hi, notif->t1_lo);
+	shwt = skb_hwtstamps(status.skb);
+	shwt->hwtstamp = ktime_set(0, ts_10ns * 10);
+
+	IWL_DEBUG_INFO(mvm,
+		       "Time sync: TX event - report frame t1=%llu t4=%llu\n",
+		       ktime_to_ns(shwt->hwtstamp),
+		       ktime_to_ns(status.ack_hwtstamp));
+	ieee80211_tx_status_ext(mvm->hw, &status);
+}
+
+int iwl_mvm_time_sync_config(struct iwl_mvm *mvm, u8 *addr, u32 protocols)
+{
+	struct iwl_time_sync_cfg_cmd cmd = {};
+	int err;
+
+	lockdep_assert_held(&mvm->mutex);
+
+	if (!fw_has_capa(&mvm->fw->ucode_capa,
+			 IWL_UCODE_TLV_CAPA_TIME_SYNC_BOTH_FTM_TM))
+		return -EINVAL;
+
+	/* The fw only supports one peer. We do allow reconfiguration of the
+	 * same peer for cases of fw reset etc.
+	 */
+	if (mvm->time_sync.active &&
+	    !ether_addr_equal(addr, mvm->time_sync.peer_addr)) {
+		IWL_DEBUG_INFO(mvm, "Time sync: reject config for peer: %pM\n",
+			       addr);
+		return -ENOBUFS;
+	}
+
+	if (protocols & ~(IWL_TIME_SYNC_PROTOCOL_TM |
+			  IWL_TIME_SYNC_PROTOCOL_FTM))
+		return -EINVAL;
+
+	cmd.protocols = cpu_to_le32(protocols);
+
+	ether_addr_copy(cmd.peer_addr, addr);
+
+	err = iwl_mvm_send_cmd_pdu(mvm,
+				   WIDE_ID(DATA_PATH_GROUP,
+					   WNM_80211V_TIMING_MEASUREMENT_CONFIG_CMD),
+				   0, sizeof(cmd), &cmd);
+	if (err) {
+		IWL_ERR(mvm, "Failed to send time sync cfg cmd: %d\n", err);
+	} else {
+		mvm->time_sync.active = protocols != 0;
+		ether_addr_copy(mvm->time_sync.peer_addr, addr);
+		IWL_DEBUG_INFO(mvm, "Time sync: set peer addr=%pM\n", addr);
+	}
+
+	return err;
+}
+
+void iwl_mvm_time_sync_sta_rm(struct iwl_mvm *mvm, struct ieee80211_sta *sta)
+{
+	/* Disable time sync with this station */
+	iwl_mvm_time_sync_config(mvm, sta->addr, 0);
+
+	skb_queue_purge(&mvm->time_sync.frame_list);
+}