igc: Add support for PTP .getcyclesx64()

Add support for using Timer 1 (i225/i226 have 4 timer registers) as a
free-running clock (the "cycles" clock) in addition to Timer 0 (the
default, "adjustable clock"). The objective is to allow taprio/etf
offloading to coexist with PTP vclocks.

Besides the implementation of .getcyclesx64() for i225/i226, to keep
timestamping working when vclocks are in use, we also need to add
support for TX and RX timestamping using the free running timer, when
the requesting socket is bound to a vclock.

On the RX side, i225/i226 can be configured to store the values of two
timers in the received packet metadata area, so it's a matter of
configuring the right registers and retrieving the right timestamp.

The TX is a bit more involved because the hardware stores a single
timestamp (with the selected timer in the TX descriptor) into one of
the timestamp registers.

Note some changes at how the timestamps are done for RX, the
conversion and adjustment of timestamps are now done closer to the
consumption of the timestamp instead of near the reception.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 39 insertions, 16 deletions

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 7059710154eb..61db1d3bfa0b 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1306,6 +1306,10 @@ static void igc_tx_olinfo_status(struct igc_ring *tx_ring,
 	olinfo_status |= IGC_SET_FLAG(tx_flags, IGC_TX_FLAGS_IPV4,
 				      (IGC_TXD_POPTS_IXSM << 8));
 
+	/* Use the second timer (free running, in general) for the timestamp */
+	olinfo_status |= IGC_SET_FLAG(tx_flags, IGC_TX_FLAGS_TSTAMP_TIMER_1,
+				      IGC_TXD_PTP2_TIMER_1);
+
 	tx_desc->read.olinfo_status = cpu_to_le32(olinfo_status);
 }
 
@@ -1649,6 +1653,8 @@ done:
 		if (igc_request_tx_tstamp(adapter, skb, &tstamp_flags)) {
 			skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 			tx_flags |= IGC_TX_FLAGS_TSTAMP | tstamp_flags;
+			if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_USE_CYCLES)
+				tx_flags |= IGC_TX_FLAGS_TSTAMP_TIMER_1;
 		} else {
 			adapter->tx_hwtstamp_skipped++;
 		}
@@ -1961,9 +1967,9 @@ static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring,
 
 static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 					 struct igc_rx_buffer *rx_buffer,
-					 struct xdp_buff *xdp,
-					 ktime_t timestamp)
+					 struct igc_xdp_buff *ctx)
 {
+	struct xdp_buff *xdp = &ctx->xdp;
 	unsigned int metasize = xdp->data - xdp->data_meta;
 	unsigned int size = xdp->data_end - xdp->data;
 	unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size);
@@ -1980,8 +1986,10 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 	if (unlikely(!skb))
 		return NULL;
 
-	if (timestamp)
-		skb_hwtstamps(skb)->hwtstamp = timestamp;
+	if (ctx->rx_ts) {
+		skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP_NETDEV;
+		skb_hwtstamps(skb)->netdev_data = ctx->rx_ts;
+	}
 
 	/* Determine available headroom for copy */
 	headlen = size;
@@ -2581,11 +2589,10 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 	int xdp_status = 0, rx_buffer_pgcnt;
 
 	while (likely(total_packets < budget)) {
-		union igc_adv_rx_desc *rx_desc;
+		struct igc_xdp_buff ctx = { .rx_ts = NULL };
 		struct igc_rx_buffer *rx_buffer;
+		union igc_adv_rx_desc *rx_desc;
 		unsigned int size, truesize;
-		struct igc_xdp_buff ctx;
-		ktime_t timestamp = 0;
 		int pkt_offset = 0;
 		void *pktbuf;
 
@@ -2612,9 +2619,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 		pktbuf = page_address(rx_buffer->page) + rx_buffer->page_offset;
 
 		if (igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP)) {
-			timestamp = igc_ptp_rx_pktstamp(q_vector->adapter,
-							pktbuf);
-			ctx.rx_ts = timestamp;
+			ctx.rx_ts = pktbuf;
 			pkt_offset = IGC_TS_HDR_LEN;
 			size -= IGC_TS_HDR_LEN;
 		}
@@ -2651,8 +2656,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 		else if (ring_uses_build_skb(rx_ring))
 			skb = igc_build_skb(rx_ring, rx_buffer, &ctx.xdp);
 		else
-			skb = igc_construct_skb(rx_ring, rx_buffer, &ctx.xdp,
-						timestamp);
+			skb = igc_construct_skb(rx_ring, rx_buffer, &ctx);
 
 		/* exit if we failed to retrieve a buffer */
 		if (!skb) {
@@ -2801,9 +2805,7 @@ static int igc_clean_rx_irq_zc(struct igc_q_vector *q_vector, const int budget)
 		ctx->rx_desc = desc;
 
 		if (igc_test_staterr(desc, IGC_RXDADV_STAT_TSIP)) {
-			timestamp = igc_ptp_rx_pktstamp(q_vector->adapter,
-							bi->xdp->data);
-			ctx->rx_ts = timestamp;
+			ctx->rx_ts = bi->xdp->data;
 
 			bi->xdp->data += IGC_TS_HDR_LEN;
 
@@ -6560,6 +6562,24 @@ int igc_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
 	return 0;
 }
 
+static ktime_t igc_get_tstamp(struct net_device *dev,
+			      const struct skb_shared_hwtstamps *hwtstamps,
+			      bool cycles)
+{
+	struct igc_adapter *adapter = netdev_priv(dev);
+	struct igc_inline_rx_tstamps *tstamp;
+	ktime_t timestamp;
+
+	tstamp = hwtstamps->netdev_data;
+
+	if (cycles)
+		timestamp = igc_ptp_rx_pktstamp(adapter, tstamp->timer1);
+	else
+		timestamp = igc_ptp_rx_pktstamp(adapter, tstamp->timer0);
+
+	return timestamp;
+}
+
 static const struct net_device_ops igc_netdev_ops = {
 	.ndo_open		= igc_open,
 	.ndo_stop		= igc_close,
@@ -6577,6 +6597,7 @@ static const struct net_device_ops igc_netdev_ops = {
 	.ndo_bpf		= igc_bpf,
 	.ndo_xdp_xmit		= igc_xdp_xmit,
 	.ndo_xsk_wakeup		= igc_xsk_wakeup,
+	.ndo_get_tstamp		= igc_get_tstamp,
 };
 
 /* PCIe configuration access */
@@ -6680,9 +6701,11 @@ static int igc_xdp_rx_hash(const struct xdp_md *_ctx, u32 *hash,
 static int igc_xdp_rx_timestamp(const struct xdp_md *_ctx, u64 *timestamp)
 {
 	const struct igc_xdp_buff *ctx = (void *)_ctx;
+	struct igc_adapter *adapter = netdev_priv(ctx->xdp.rxq->dev);
+	struct igc_inline_rx_tstamps *tstamp = ctx->rx_ts;
 
 	if (igc_test_staterr(ctx->rx_desc, IGC_RXDADV_STAT_TSIP)) {
-		*timestamp = ctx->rx_ts;
+		*timestamp = igc_ptp_rx_pktstamp(adapter, tstamp->timer0);
 
 		return 0;
 	}