net: microchip: lan743x: improve throughput with rx timestamp config

Currently all RX frames are timestamped which results in a performance
penalty when timestamping is not needed.  The default is now being
changed to not timestamp any Rx frames (HWTSTAMP_FILTER_NONE), but
support has been added to allow changing the desired RX timestamping
mode (HWTSTAMP_FILTER_ALL -  which was the previous setting and
HWTSTAMP_FILTER_PTP_V2_EVENT are now supported) using
SIOCSHWTSTAMP. All settings were tested using the hwstamp_ctl application.
It is also noted that ptp4l, when started, preconfigures the device to
timestamp using HWTSTAMP_FILTER_PTP_V2_EVENT, so this driver continues
to work properly "out of the box".

Test setup:  x64 PC with LAN7430 ---> x64 PC as partner

iperf3 with - Timestamp all incoming packets:
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-5.05   sec   517 MBytes   859 Mbits/sec    0    sender
[  5]   0.00-5.00   sec   515 MBytes   864 Mbits/sec         receiver

iperf Done.

iperf3 with - Timestamp only PTP packets:
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-5.04   sec   563 MBytes   937 Mbits/sec    0    sender
[  5]   0.00-5.00   sec   561 MBytes   941 Mbits/sec         receiver
Signed-off-by: Vishvambar Panth S <vishvambarpanth.s@microchip.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20231020185801.25649-1-vishvambarpanth.s@microchip.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/microchip/lan743x_ethtool.c

@@ -1047,7 +1047,8 @@ static int lan743x_ethtool_get_ts_info(struct net_device *netdev,
 			    BIT(HWTSTAMP_TX_ON) |
 			    BIT(HWTSTAMP_TX_ONESTEP_SYNC);
 	ts_info->rx_filters = BIT(HWTSTAMP_FILTER_NONE) |
-			      BIT(HWTSTAMP_FILTER_ALL);
+			      BIT(HWTSTAMP_FILTER_ALL) |
+			      BIT(HWTSTAMP_FILTER_PTP_V2_EVENT);
 	return 0;
 }
 

drivers/net/ethernet/microchip/lan743x_main.c

@@ -1870,6 +1870,50 @@ static int lan743x_tx_get_avail_desc(struct lan743x_tx *tx)
 		return last_head - last_tail - 1;
 }
 
+static void lan743x_rx_cfg_b_tstamp_config(struct lan743x_adapter *adapter,
+					   int rx_ts_config)
+{
+	int channel_number;
+	int index;
+	u32 data;
+
+	for (index = 0; index < LAN743X_USED_RX_CHANNELS; index++) {
+		channel_number = adapter->rx[index].channel_number;
+		data = lan743x_csr_read(adapter, RX_CFG_B(channel_number));
+		data &= RX_CFG_B_TS_MASK_;
+		data |= rx_ts_config;
+		lan743x_csr_write(adapter, RX_CFG_B(channel_number),
+				  data);
+	}
+}
+
+int lan743x_rx_set_tstamp_mode(struct lan743x_adapter *adapter,
+			       int rx_filter)
+{
+	u32 data;
+
+	switch (rx_filter) {
+	case HWTSTAMP_FILTER_PTP_V2_EVENT:
+			lan743x_rx_cfg_b_tstamp_config(adapter,
+						       RX_CFG_B_TS_DESCR_EN_);
+			data = lan743x_csr_read(adapter, PTP_RX_TS_CFG);
+			data |= PTP_RX_TS_CFG_EVENT_MSGS_;
+			lan743x_csr_write(adapter, PTP_RX_TS_CFG, data);
+			break;
+	case HWTSTAMP_FILTER_NONE:
+			lan743x_rx_cfg_b_tstamp_config(adapter,
+						       RX_CFG_B_TS_NONE_);
+			break;
+	case HWTSTAMP_FILTER_ALL:
+			lan743x_rx_cfg_b_tstamp_config(adapter,
+						       RX_CFG_B_TS_ALL_RX_);
+			break;
+	default:
+			return -ERANGE;
+	}
+	return 0;
+}
+
 void lan743x_tx_set_timestamping_mode(struct lan743x_tx *tx,
 				      bool enable_timestamping,
 				      bool enable_onestep_sync)
@@ -2944,7 +2988,6 @@ static int lan743x_rx_open(struct lan743x_rx *rx)
 		data |= RX_CFG_B_RX_PAD_2_;
 	data &= ~RX_CFG_B_RX_RING_LEN_MASK_;
 	data |= ((rx->ring_size) & RX_CFG_B_RX_RING_LEN_MASK_);
-	data |= RX_CFG_B_TS_ALL_RX_;
 	if (!(adapter->csr.flags & LAN743X_CSR_FLAG_IS_A0))
 		data |= RX_CFG_B_RDMABL_512_;
 

drivers/net/ethernet/microchip/lan743x_main.h

@@ -522,6 +522,8 @@
 	(((u32)(rx_latency)) & 0x0000FFFF)
 #define PTP_CAP_INFO				(0x0A60)
 #define PTP_CAP_INFO_TX_TS_CNT_GET_(reg_val)	(((reg_val) & 0x00000070) >> 4)
+#define PTP_RX_TS_CFG				(0x0A68)
+#define PTP_RX_TS_CFG_EVENT_MSGS_               GENMASK(3, 0)
 
 #define PTP_TX_MOD				(0x0AA4)
 #define PTP_TX_MOD_TX_PTP_SYNC_TS_INSERT_	(0x10000000)
@@ -657,6 +659,9 @@
 
 #define RX_CFG_B(channel)			(0xC44 + ((channel) << 6))
 #define RX_CFG_B_TS_ALL_RX_			BIT(29)
+#define RX_CFG_B_TS_DESCR_EN_			BIT(28)
+#define RX_CFG_B_TS_NONE_			0
+#define RX_CFG_B_TS_MASK_			(0xCFFFFFFF)
 #define RX_CFG_B_RX_PAD_MASK_			(0x03000000)
 #define RX_CFG_B_RX_PAD_0_			(0x00000000)
 #define RX_CFG_B_RX_PAD_2_			(0x02000000)
@@ -991,6 +996,9 @@ struct lan743x_rx {
 	struct sk_buff *skb_head, *skb_tail;
 };
 
+int lan743x_rx_set_tstamp_mode(struct lan743x_adapter *adapter,
+			       int rx_filter);
+
 /* SGMII Link Speed Duplex status */
 enum lan743x_sgmii_lsd {
 	POWER_DOWN = 0,

drivers/net/ethernet/microchip/lan743x_ptp.c

@@ -1493,6 +1493,10 @@ int lan743x_ptp_open(struct lan743x_adapter *adapter)
 	temp = lan743x_csr_read(adapter, PTP_TX_MOD2);
 	temp |= PTP_TX_MOD2_TX_PTP_CLR_UDPV4_CHKSUM_;
 	lan743x_csr_write(adapter, PTP_TX_MOD2, temp);
+
+	/* Default Timestamping */
+	lan743x_rx_set_tstamp_mode(adapter, HWTSTAMP_FILTER_NONE);
+
 	lan743x_ptp_enable(adapter);
 	lan743x_csr_write(adapter, INT_EN_SET, INT_BIT_1588_);
 	lan743x_csr_write(adapter, PTP_INT_EN_SET,
@@ -1653,6 +1657,9 @@ static void lan743x_ptp_disable(struct lan743x_adapter *adapter)
 {
 	struct lan743x_ptp *ptp = &adapter->ptp;
 
+	/* Disable Timestamping */
+	lan743x_rx_set_tstamp_mode(adapter, HWTSTAMP_FILTER_NONE);
+
 	mutex_lock(&ptp->command_lock);
 	if (!lan743x_ptp_is_enabled(adapter)) {
 		netif_warn(adapter, drv, adapter->netdev,
@@ -1785,6 +1792,8 @@ int lan743x_ptp_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
 		break;
 	}
 
+	ret = lan743x_rx_set_tstamp_mode(adapter, config.rx_filter);
+
 	if (!ret)
 		return copy_to_user(ifr->ifr_data, &config,
 			sizeof(config)) ? -EFAULT : 0;