bnxt_en: Implement ethtool .get_tunable() for ETHTOOL_PFC_PREVENTION_TOUT

Return the current PFC watchdog timeout value if it is supported.

Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20250917040839.1924698-10-michael.chan@broadcom.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

4 files changed, 81 insertions, 0 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index c49a4755a94d..d59612d1e176 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -14748,6 +14748,23 @@ static bool bnxt_fw_pre_resv_vnics(struct bnxt *bp)
 	return false;
 }
 
+static void bnxt_hwrm_pfcwd_qcaps(struct bnxt *bp)
+{
+	struct hwrm_queue_pfcwd_timeout_qcaps_output *resp;
+	struct hwrm_queue_pfcwd_timeout_qcaps_input *req;
+	int rc;
+
+	bp->max_pfcwd_tmo_ms = 0;
+	rc = hwrm_req_init(bp, req, HWRM_QUEUE_PFCWD_TIMEOUT_QCAPS);
+	if (rc)
+		return;
+	resp = hwrm_req_hold(bp, req);
+	rc = hwrm_req_send_silent(bp, req);
+	if (!rc)
+		bp->max_pfcwd_tmo_ms = le16_to_cpu(resp->max_pfcwd_timeout);
+	hwrm_req_drop(bp, req);
+}
+
 static int bnxt_fw_init_one_p1(struct bnxt *bp)
 {
 	int rc;
@@ -14825,6 +14842,7 @@ static int bnxt_fw_init_one_p2(struct bnxt *bp)
 	if (bnxt_fw_pre_resv_vnics(bp))
 		bp->fw_cap |= BNXT_FW_CAP_PRE_RESV_VNICS;
 
+	bnxt_hwrm_pfcwd_qcaps(bp);
 	bnxt_hwrm_func_qcfg(bp);
 	bnxt_hwrm_vnic_qcaps(bp);
 	bnxt_hwrm_port_led_qcaps(bp);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index c0f46eaf91c0..06a4c2afdf8a 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -2426,6 +2426,8 @@ struct bnxt {
 	u8			max_q;
 	u8			num_tc;
 
+	u16			max_pfcwd_tmo_ms;
+
 	u8			tph_mode;
 
 	unsigned int		current_interval;
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 2830a2b17a27..d94a8a2bf0f9 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -4399,6 +4399,23 @@ static int bnxt_get_eee(struct net_device *dev, struct ethtool_keee *edata)
 	return 0;
 }
 
+static int bnxt_hwrm_pfcwd_qcfg(struct bnxt *bp, u16 *val)
+{
+	struct hwrm_queue_pfcwd_timeout_qcfg_output *resp;
+	struct hwrm_queue_pfcwd_timeout_qcfg_input *req;
+	int rc;
+
+	rc = hwrm_req_init(bp, req, HWRM_QUEUE_PFCWD_TIMEOUT_QCFG);
+	if (rc)
+		return rc;
+	resp = hwrm_req_hold(bp, req);
+	rc = hwrm_req_send(bp, req);
+	if (!rc)
+		*val = le16_to_cpu(resp->pfcwd_timeout_value);
+	hwrm_req_drop(bp, req);
+	return rc;
+}
+
 static int bnxt_set_tunable(struct net_device *dev,
 			    const struct ethtool_tunable *tuna,
 			    const void *data)
@@ -4431,6 +4448,10 @@ static int bnxt_get_tunable(struct net_device *dev,
 	case ETHTOOL_RX_COPYBREAK:
 		*(u32 *)data = bp->rx_copybreak;
 		break;
+	case ETHTOOL_PFC_PREVENTION_TOUT:
+		if (!bp->max_pfcwd_tmo_ms)
+			return -EOPNOTSUPP;
+		return bnxt_hwrm_pfcwd_qcfg(bp, data);
 	default:
 		return -EOPNOTSUPP;
 	}
diff --git a/include/linux/bnxt/hsi.h b/include/linux/bnxt/hsi.h
index 8c5dac3b3ef3..23e7b1290a92 100644
--- a/include/linux/bnxt/hsi.h
+++ b/include/linux/bnxt/hsi.h
@@ -6751,6 +6751,46 @@ struct hwrm_queue_dscp2pri_cfg_output {
 	u8	valid;
 };
 
+/* hwrm_queue_pfcwd_timeout_qcaps_input (size:128b/16B) */
+struct hwrm_queue_pfcwd_timeout_qcaps_input {
+	__le16	req_type;
+	__le16	cmpl_ring;
+	__le16	seq_id;
+	__le16	target_id;
+	__le64	resp_addr;
+};
+
+/* hwrm_queue_pfcwd_timeout_qcaps_output (size:128b/16B) */
+struct hwrm_queue_pfcwd_timeout_qcaps_output {
+	__le16	error_code;
+	__le16	req_type;
+	__le16	seq_id;
+	__le16	resp_len;
+	__le16	max_pfcwd_timeout;
+	u8	unused_0[5];
+	u8	valid;
+};
+
+/* hwrm_queue_pfcwd_timeout_qcfg_input (size:128b/16B) */
+struct hwrm_queue_pfcwd_timeout_qcfg_input {
+	__le16	req_type;
+	__le16	cmpl_ring;
+	__le16	seq_id;
+	__le16	target_id;
+	__le64	resp_addr;
+};
+
+/* hwrm_queue_pfcwd_timeout_qcfg_output (size:128b/16B) */
+struct hwrm_queue_pfcwd_timeout_qcfg_output {
+	__le16	error_code;
+	__le16	req_type;
+	__le16	seq_id;
+	__le16	resp_len;
+	__le16	pfcwd_timeout_value;
+	u8	unused_0[5];
+	u8	valid;
+};
+
 /* hwrm_vnic_alloc_input (size:192b/24B) */
 struct hwrm_vnic_alloc_input {
 	__le16	req_type;