bnxt_en: Transmit and retrieve packet timestamps

Setup the TXBD to enable TX timestamp if requested.  At TX packet DMA
completion, if we requested TX timestamp on that packet, we defer to
.do_aux_work() to obtain the TX timestamp from the firmware before we
free the TX SKB.

v2: Use .do_aux_work() to get the TX timestamp from firmware.

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>

1 files changed, 94 insertions, 0 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
index cea7220f3d1b..f698b6bd4ff8 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
@@ -15,10 +15,32 @@
 #include <linux/net_tstamp.h>
 #include <linux/timecounter.h>
 #include <linux/timekeeping.h>
+#include <linux/ptp_classify.h>
 #include "bnxt_hsi.h"
 #include "bnxt.h"
 #include "bnxt_ptp.h"
 
+int bnxt_ptp_parse(struct sk_buff *skb, u16 *seq_id)
+{
+	unsigned int ptp_class;
+	struct ptp_header *hdr;
+
+	ptp_class = ptp_classify_raw(skb);
+
+	switch (ptp_class & PTP_CLASS_VMASK) {
+	case PTP_CLASS_V1:
+	case PTP_CLASS_V2:
+		hdr = ptp_parse_header(skb, ptp_class);
+		if (!hdr)
+			return -EINVAL;
+
+		*seq_id	 = ntohs(hdr->sequence_id);
+		return 0;
+	default:
+		return -ERANGE;
+	}
+}
+
 static int bnxt_ptp_settime(struct ptp_clock_info *ptp_info,
 			    const struct timespec64 *ts)
 {
@@ -57,6 +79,28 @@ static void bnxt_ptp_get_current_time(struct bnxt *bp)
 	spin_unlock_bh(&ptp->ptp_lock);
 }
 
+static int bnxt_hwrm_port_ts_query(struct bnxt *bp, u32 flags, u64 *ts)
+{
+	struct hwrm_port_ts_query_output *resp = bp->hwrm_cmd_resp_addr;
+	struct hwrm_port_ts_query_input req = {0};
+	int rc;
+
+	bnxt_hwrm_cmd_hdr_init(bp, &req, HWRM_PORT_TS_QUERY, -1, -1);
+	req.flags = cpu_to_le32(flags);
+	if ((flags & PORT_TS_QUERY_REQ_FLAGS_PATH) ==
+	    PORT_TS_QUERY_REQ_FLAGS_PATH_TX) {
+		req.enables = cpu_to_le16(BNXT_PTP_QTS_TX_ENABLES);
+		req.ptp_seq_id = cpu_to_le32(bp->ptp_cfg->tx_seqid);
+		req.ts_req_timeout = cpu_to_le16(BNXT_PTP_QTS_TIMEOUT);
+	}
+	mutex_lock(&bp->hwrm_cmd_lock);
+	rc = _hwrm_send_message(bp, &req, sizeof(req), HWRM_CMD_TIMEOUT);
+	if (!rc)
+		*ts = le64_to_cpu(resp->ptp_msg_ts);
+	mutex_unlock(&bp->hwrm_cmd_lock);
+	return rc;
+}
+
 static int bnxt_ptp_gettimex(struct ptp_clock_info *ptp_info,
 			     struct timespec64 *ts,
 			     struct ptp_system_timestamp *sts)
@@ -269,16 +313,62 @@ static u64 bnxt_cc_read(const struct cyclecounter *cc)
 	return bnxt_refclk_read(ptp->bp, NULL);
 }
 
+static void bnxt_stamp_tx_skb(struct bnxt *bp, struct sk_buff *skb)
+{
+	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
+	struct skb_shared_hwtstamps timestamp;
+	u64 ts = 0, ns = 0;
+	int rc;
+
+	rc = bnxt_hwrm_port_ts_query(bp, PORT_TS_QUERY_REQ_FLAGS_PATH_TX, &ts);
+	if (!rc) {
+		memset(&timestamp, 0, sizeof(timestamp));
+		spin_lock_bh(&ptp->ptp_lock);
+		ns = timecounter_cyc2time(&ptp->tc, ts);
+		spin_unlock_bh(&ptp->ptp_lock);
+		timestamp.hwtstamp = ns_to_ktime(ns);
+		skb_tstamp_tx(ptp->tx_skb, &timestamp);
+	} else {
+		netdev_err(bp->dev, "TS query for TX timer failed rc = %x\n",
+			   rc);
+	}
+
+	dev_kfree_skb_any(ptp->tx_skb);
+	ptp->tx_skb = NULL;
+	atomic_inc(&ptp->tx_avail);
+}
+
 static long bnxt_ptp_ts_aux_work(struct ptp_clock_info *ptp_info)
 {
 	struct bnxt_ptp_cfg *ptp = container_of(ptp_info, struct bnxt_ptp_cfg,
 						ptp_info);
+	unsigned long now = jiffies;
 	struct bnxt *bp = ptp->bp;
 
+	if (ptp->tx_skb)
+		bnxt_stamp_tx_skb(bp, ptp->tx_skb);
+
+	if (!time_after_eq(now, ptp->next_period))
+		return ptp->next_period - now;
+
 	bnxt_ptp_get_current_time(bp);
+	ptp->next_period = now + HZ;
 	return HZ;
 }
 
+int bnxt_get_tx_ts_p5(struct bnxt *bp, struct sk_buff *skb)
+{
+	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
+
+	if (ptp->tx_skb) {
+		netdev_err(bp->dev, "deferring skb:one SKB is still outstanding\n");
+		return -EBUSY;
+	}
+	ptp->tx_skb = skb;
+	ptp_schedule_worker(ptp->ptp_clock, 0);
+	return 0;
+}
+
 int bnxt_get_rx_ts_p5(struct bnxt *bp, u64 *ts, u32 pkt_ts)
 {
 	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
@@ -375,5 +465,9 @@ void bnxt_ptp_clear(struct bnxt *bp)
 		ptp_clock_unregister(ptp->ptp_clock);
 
 	ptp->ptp_clock = NULL;
+	if (ptp->tx_skb) {
+		dev_kfree_skb_any(ptp->tx_skb);
+		ptp->tx_skb = NULL;
+	}
 	bnxt_unmap_ptp_regs(bp);
 }