1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/net/ethernet/google/gve/gve_ptp.c b/drivers/net/ethernet/google/gve/gve_ptp.c
new file mode 100644
index 000000000000..e96247c9d68d
--- /dev/null
+++ b/drivers/net/ethernet/google/gve/gve_ptp.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/* Google virtual Ethernet (gve) driver
+ *
+ * Copyright (C) 2025 Google LLC
+ */
+
+#include "gve.h"
+#include "gve_adminq.h"
+
+/* Interval to schedule a nic timestamp calibration, 250ms. */
+#define GVE_NIC_TS_SYNC_INTERVAL_MS 250
+
+/* Read the nic timestamp from hardware via the admin queue. */
+int gve_clock_nic_ts_read(struct gve_priv *priv)
+{
+	u64 nic_raw;
+	int err;
+
+	err = gve_adminq_report_nic_ts(priv, priv->nic_ts_report_bus);
+	if (err)
+		return err;
+
+	nic_raw = be64_to_cpu(priv->nic_ts_report->nic_timestamp);
+	WRITE_ONCE(priv->last_sync_nic_counter, nic_raw);
+
+	return 0;
+}
+
+static long gve_ptp_do_aux_work(struct ptp_clock_info *info)
+{
+	const struct gve_ptp *ptp = container_of(info, struct gve_ptp, info);
+	struct gve_priv *priv = ptp->priv;
+	int err;
+
+	if (gve_get_reset_in_progress(priv) || !gve_get_admin_queue_ok(priv))
+		goto out;
+
+	err = gve_clock_nic_ts_read(priv);
+	if (err && net_ratelimit())
+		dev_err(&priv->pdev->dev,
+			"%s read err %d\n", __func__, err);
+
+out:
+	return msecs_to_jiffies(GVE_NIC_TS_SYNC_INTERVAL_MS);
+}
+
+static const struct ptp_clock_info gve_ptp_caps = {
+	.owner          = THIS_MODULE,
+	.name		= "gve clock",
+	.do_aux_work	= gve_ptp_do_aux_work,
+};
+
+static int gve_ptp_init(struct gve_priv *priv)
+{
+	struct gve_ptp *ptp;
+	int err;
+
+	if (!priv->nic_timestamp_supported) {
+		dev_dbg(&priv->pdev->dev, "Device does not support PTP\n");
+		return -EOPNOTSUPP;
+	}
+
+	priv->ptp = kzalloc(sizeof(*priv->ptp), GFP_KERNEL);
+	if (!priv->ptp)
+		return -ENOMEM;
+
+	ptp = priv->ptp;
+	ptp->info = gve_ptp_caps;
+	ptp->clock = ptp_clock_register(&ptp->info, &priv->pdev->dev);
+
+	if (IS_ERR(ptp->clock)) {
+		dev_err(&priv->pdev->dev, "PTP clock registration failed\n");
+		err  = PTR_ERR(ptp->clock);
+		goto free_ptp;
+	}
+
+	ptp->priv = priv;
+	return 0;
+
+free_ptp:
+	kfree(ptp);
+	priv->ptp = NULL;
+	return err;
+}
+
+static void gve_ptp_release(struct gve_priv *priv)
+{
+	struct gve_ptp *ptp = priv->ptp;
+
+	if (!ptp)
+		return;
+
+	if (ptp->clock)
+		ptp_clock_unregister(ptp->clock);
+
+	kfree(ptp);
+	priv->ptp = NULL;
+}
+
+int gve_init_clock(struct gve_priv *priv)
+{
+	int err;
+
+	if (!priv->nic_timestamp_supported)
+		return 0;
+
+	err = gve_ptp_init(priv);
+	if (err)
+		return err;
+
+	priv->nic_ts_report =
+		dma_alloc_coherent(&priv->pdev->dev,
+				   sizeof(struct gve_nic_ts_report),
+				   &priv->nic_ts_report_bus,
+				   GFP_KERNEL);
+	if (!priv->nic_ts_report) {
+		dev_err(&priv->pdev->dev, "%s dma alloc error\n", __func__);
+		err = -ENOMEM;
+		goto release_ptp;
+	}
+
+	return 0;
+
+release_ptp:
+	gve_ptp_release(priv);
+	return err;
+}
+
+void gve_teardown_clock(struct gve_priv *priv)
+{
+	gve_ptp_release(priv);
+
+	if (priv->nic_ts_report) {
+		dma_free_coherent(&priv->pdev->dev,
+				  sizeof(struct gve_nic_ts_report),
+				  priv->nic_ts_report, priv->nic_ts_report_bus);
+		priv->nic_ts_report = NULL;
+	}
+}