[PATCH net-next v2 2/6] bnxt_en: Add PTP .getcrosststamp() interface to get device/host times

[Michael Chan <michael.chan@broadcom.com>]

From: Pavan Chebbi <pavan.chebbi@broadcom.com>

.getcrosststamp() helps the applications to obtain a snapshot of
device and host time almost taken at the same time. This function
will report PCIe PTM device and host times to any application using
the ioctl PTP_SYS_OFFSET_PRECISE. The device time from the HW is
48-bit and needs to be converted to 64-bit.

Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
v2: Add check for x86 support

v1: https://lore.kernel.org/netdev/20251126215648.1885936-8-michael.chan@broadcom.com/
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c     |  2 +
 drivers/net/ethernet/broadcom/bnxt/bnxt.h     |  1 +
 drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c | 47 +++++++++++++++++++
 3 files changed, 50 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index d17d0ea89c36..9ab9ebd57367 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -9691,6 +9691,8 @@ static int __bnxt_hwrm_func_qcaps(struct bnxt *bp)
 		bp->fw_cap |= BNXT_FW_CAP_EXT_HW_STATS_SUPPORTED;
 	if (BNXT_PF(bp) && (flags_ext & FUNC_QCAPS_RESP_FLAGS_EXT_PTP_PPS_SUPPORTED))
 		bp->fw_cap |= BNXT_FW_CAP_PTP_PPS;
+	if (flags_ext & FUNC_QCAPS_RESP_FLAGS_EXT_PTP_PTM_SUPPORTED)
+		bp->fw_cap |= BNXT_FW_CAP_PTP_PTM;
 	if (flags_ext & FUNC_QCAPS_RESP_FLAGS_EXT_PTP_64BIT_RTC_SUPPORTED)
 		bp->fw_cap |= BNXT_FW_CAP_PTP_RTC;
 	if (BNXT_PF(bp) && (flags_ext & FUNC_QCAPS_RESP_FLAGS_EXT_HOT_RESET_IF_SUPPORT))
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index f5f07a7e6b29..08d9adf52ec6 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -2518,6 +2518,7 @@ struct bnxt {
 	#define BNXT_FW_CAP_SW_MAX_RESOURCE_LIMITS	BIT_ULL(41)
 	#define BNXT_FW_CAP_NPAR_1_2			BIT_ULL(42)
 	#define BNXT_FW_CAP_MIRROR_ON_ROCE		BIT_ULL(43)
+	#define BNXT_FW_CAP_PTP_PTM			BIT_ULL(44)
 
 	u32			fw_dbg_cap;
 
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
index a8a74f07bb54..75ad385f5f79 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
@@ -882,6 +882,49 @@ void bnxt_tx_ts_cmp(struct bnxt *bp, struct bnxt_napi *bnapi,
 	}
 }
 
+static int bnxt_phc_get_syncdevicetime(ktime_t *device,
+				       struct system_counterval_t *system,
+				       void *ctx)
+{
+	struct bnxt_ptp_cfg *ptp = (struct bnxt_ptp_cfg *)ctx;
+	struct hwrm_func_ptp_ts_query_output *resp;
+	struct hwrm_func_ptp_ts_query_input *req;
+	struct bnxt *bp = ptp->bp;
+	u64 ptm_local_ts;
+	int rc;
+
+	rc = hwrm_req_init(bp, req, HWRM_FUNC_PTP_TS_QUERY);
+	if (rc)
+		return rc;
+	req->flags = cpu_to_le32(FUNC_PTP_TS_QUERY_REQ_FLAGS_PTM_TIME);
+	resp = hwrm_req_hold(bp, req);
+	rc = hwrm_req_send(bp, req);
+	if (rc) {
+		hwrm_req_drop(bp, req);
+		return rc;
+	}
+	ptm_local_ts = le64_to_cpu(resp->ptm_local_ts);
+	*device = ns_to_ktime(bnxt_timecounter_cyc2time(ptp, ptm_local_ts));
+	/* ptm_system_ts is 64-bit */
+	system->cycles = le64_to_cpu(resp->ptm_system_ts);
+	system->cs_id = CSID_X86_ART;
+	system->use_nsecs = true;
+
+	hwrm_req_drop(bp, req);
+
+	return 0;
+}
+
+static int bnxt_ptp_getcrosststamp(struct ptp_clock_info *ptp_info,
+				   struct system_device_crosststamp *xtstamp)
+{
+	struct bnxt_ptp_cfg *ptp = container_of(ptp_info, struct bnxt_ptp_cfg,
+						ptp_info);
+
+	return get_device_system_crosststamp(bnxt_phc_get_syncdevicetime,
+					     ptp, NULL, xtstamp);
+}
+
 static const struct ptp_clock_info bnxt_ptp_caps = {
 	.owner		= THIS_MODULE,
 	.name		= "bnxt clock",
@@ -1094,6 +1137,10 @@ int bnxt_ptp_init(struct bnxt *bp)
 		if (bnxt_ptp_pps_init(bp))
 			netdev_err(bp->dev, "1pps not initialized, continuing without 1pps support\n");
 	}
+	if ((bp->fw_cap & BNXT_FW_CAP_PTP_PTM) && pcie_ptm_enabled(bp->pdev) &&
+	    boot_cpu_has(X86_FEATURE_ART))
+		ptp->ptp_info.getcrosststamp = bnxt_ptp_getcrosststamp;
+
 	ptp->ptp_clock = ptp_clock_register(&ptp->ptp_info, &bp->pdev->dev);
 	if (IS_ERR(ptp->ptp_clock)) {
 		int err = PTR_ERR(ptp->ptp_clock);
-- 
2.51.0