bnxt_en: Get the RX packet timestamp

If the RX packet is timestamped by the hardware, the RX completion
record will contain the lower 32-bit of the timestamp.  This needs
to be combined with the upper 16-bit of the periodic timestamp that
we get from the timer.  The previous snapshot in ptp->old_timer is
used to make sure that the snapshot is not ahead of the RX timestamp
and we adjust for wrap-around if needed.

v2: Make ptp->old_time read access safe on 32-bit CPUs.

Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -1709,9 +1709,9 @@ static int bnxt_rx_pkt(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 	u8 *data_ptr, agg_bufs, cmp_type;
 	dma_addr_t dma_addr;
 	struct sk_buff *skb;
+	u32 flags, misc;
 	void *data;
 	int rc = 0;
-	u32 misc;
 
 	rxcmp = (struct rx_cmp *)
 			&cpr->cp_desc_ring[CP_RING(cp_cons)][CP_IDX(cp_cons)];
@@ -1809,7 +1809,8 @@ static int bnxt_rx_pkt(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 		goto next_rx_no_len;
 	}
 
-	len = le32_to_cpu(rxcmp->rx_cmp_len_flags_type) >> RX_CMP_LEN_SHIFT;
+	flags = le32_to_cpu(rxcmp->rx_cmp_len_flags_type);
+	len = flags >> RX_CMP_LEN_SHIFT;
 	dma_addr = rx_buf->mapping;
 
 	if (bnxt_rx_xdp(bp, rxr, cons, data, &data_ptr, &len, event)) {
@@ -1886,6 +1887,24 @@ static int bnxt_rx_pkt(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 		}
 	}
 
+	if (unlikely((flags & RX_CMP_FLAGS_ITYPES_MASK) ==
+		     RX_CMP_FLAGS_ITYPE_PTP_W_TS)) {
+		if (bp->flags & BNXT_FLAG_CHIP_P5) {
+			u32 cmpl_ts = le32_to_cpu(rxcmp1->rx_cmp_timestamp);
+			u64 ns, ts;
+
+			if (!bnxt_get_rx_ts_p5(bp, &ts, cmpl_ts)) {
+				struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
+
+				spin_lock_bh(&ptp->ptp_lock);
+				ns = timecounter_cyc2time(&ptp->tc, ts);
+				spin_unlock_bh(&ptp->ptp_lock);
+				memset(skb_hwtstamps(skb), 0,
+				       sizeof(*skb_hwtstamps(skb)));
+				skb_hwtstamps(skb)->hwtstamp = ns_to_ktime(ns);
+			}
+		}
+	}
 	bnxt_deliver_skb(bp, bnapi, skb);
 	rc = 1;
 

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -159,6 +159,7 @@ struct rx_cmp {
 	#define RX_CMP_FLAGS_RSS_VALID				(1 << 10)
 	#define RX_CMP_FLAGS_UNUSED				(1 << 11)
 	 #define RX_CMP_FLAGS_ITYPES_SHIFT			 12
+	 #define RX_CMP_FLAGS_ITYPES_MASK			 0xf000
 	 #define RX_CMP_FLAGS_ITYPE_UNKNOWN			 (0 << 12)
 	 #define RX_CMP_FLAGS_ITYPE_IP				 (1 << 12)
 	 #define RX_CMP_FLAGS_ITYPE_TCP				 (2 << 12)
@@ -240,7 +241,7 @@ struct rx_cmp_ext {
 	#define RX_CMPL_CFA_CODE_MASK				(0xffff << 16)
 	 #define RX_CMPL_CFA_CODE_SFT				 16
 
-	__le32 rx_cmp_unused3;
+	__le32 rx_cmp_timestamp;
 };
 
 #define RX_CMP_L2_ERRORS						\

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c

@@ -279,6 +279,22 @@ static long bnxt_ptp_ts_aux_work(struct ptp_clock_info *ptp_info)
 	return HZ;
 }
 
+int bnxt_get_rx_ts_p5(struct bnxt *bp, u64 *ts, u32 pkt_ts)
+{
+	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
+	u64 time;
+
+	if (!ptp)
+		return -ENODEV;
+
+	BNXT_READ_TIME64(ptp, time, ptp->old_time);
+	*ts = (time & BNXT_HI_TIMER_MASK) | pkt_ts;
+	if (pkt_ts < (time & BNXT_LO_TIMER_MASK))
+		*ts += BNXT_LO_TIMER_MASK + 1;
+
+	return 0;
+}
+
 void bnxt_ptp_start(struct bnxt *bp)
 {
 	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h

@@ -58,8 +58,21 @@ struct bnxt_ptp_cfg {
 	u32			refclk_mapped_regs[2];
 };
 
+#if BITS_PER_LONG == 32
+#define BNXT_READ_TIME64(ptp, dst, src)		\
+do {						\
+	spin_lock_bh(&(ptp)->ptp_lock);		\
+	(dst) = (src);				\
+	spin_unlock_bh(&(ptp)->ptp_lock);	\
+} while (0)
+#else
+#define BNXT_READ_TIME64(ptp, dst, src)		\
+	((dst) = READ_ONCE(src))
+#endif
+
 int bnxt_hwtstamp_set(struct net_device *dev, struct ifreq *ifr);
 int bnxt_hwtstamp_get(struct net_device *dev, struct ifreq *ifr);
+int bnxt_get_rx_ts_p5(struct bnxt *bp, u64 *ts, u32 pkt_ts);
 void bnxt_ptp_start(struct bnxt *bp);
 int bnxt_ptp_init(struct bnxt *bp);
 void bnxt_ptp_clear(struct bnxt *bp);