[PATCH v2 net-next 04/15] net: enetc: add link speed message support to PF driver

[wei.fang@oss.nxp.com]

From: Wei Fang <wei.fang@nxp.com>

When a VF is driven by DPDK, the VF relies on the PF to provide accurate
link speed information so that the VF-side user space application can
make correct forwarding and configuration decisions.

Therefore, add link speed message support for DPDK-owned VF. The PF will
reply the current link speed when it receives the get link speed message
from VF.

With this enhancement, VFs controlled by DPDK can obtain real-time link
speed information from the PF, improving overall link state visibility,
synchronization between PF/VF, and enabling more accurate performance
adjustments in VF-side applications.

Note that currently the link speed change notification is not supported.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
---
 .../ethernet/freescale/enetc/enetc_mailbox.h  | 30 +++++++
 .../net/ethernet/freescale/enetc/enetc_msg.c  | 85 +++++++++++++++++++
 2 files changed, 115 insertions(+)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_mailbox.h b/drivers/net/ethernet/freescale/enetc/enetc_mailbox.h
index 43b9ee2ab3e4..46446330e222 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_mailbox.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_mailbox.h
@@ -108,6 +108,7 @@ enum enetc_msg_class_id {
 	/* Common Class ID for PSI-to-VSI and VSI-to-PSI messages */
 	ENETC_MSG_CLASS_ID_MAC_FILTER		= 0x20,
 	ENETC_MSG_CLASS_ID_LINK_STATUS		= 0x80,
+	ENETC_MSG_CLASS_ID_LINK_SPEED		= 0x81,
 	ENETC_MSG_CLASS_ID_IP_REVISION		= 0xf0,
 };
 
@@ -125,6 +126,13 @@ enum enetc_msg_link_status_cmd_id {
 	ENETC_MSG_UNREGISTER_LINK_CHANGE_NOTIFIER,
 };
 
+enum enetc_msg_link_speed_cmd_id {
+	ENETC_MSG_GET_CURRENT_LINK_SPEED,
+	/* The following command IDs are not currently supported */
+	ENETC_MSG_REGISTER_SPEED_CHANGE_NOTIFIER,
+	ENETC_MSG_UNREGISTER_SPEED_CHANGE_NOTIFIER,
+};
+
 /* Class-specific error return codes of MAC filter */
 enum enetc_mac_filter_class_code {
 	ENETC_MF_CLASS_CODE_INVALID_MAC,
@@ -136,6 +144,23 @@ enum enetc_link_status_class_code {
 	ENETC_LINK_STATUS_CLASS_CODE_DOWN,
 };
 
+/* Class-specific notifications/codes of link speed */
+enum enetc_link_speed_class_code {
+	ENETC_MSG_SPEED_UNKNOWN,
+	ENETC_MSG_SPEED_10M_HD,
+	ENETC_MSG_SPEED_10M_FD,
+	ENETC_MSG_SPEED_100M_HD,
+	ENETC_MSG_SPEED_100M_FD,
+	ENETC_MSG_SPEED_1000M,
+	ENETC_MSG_SPEED_2500M,
+	ENETC_MSG_SPEED_5G,
+	ENETC_MSG_SPEED_10G,
+	ENETC_MSG_SPEED_25G,
+	ENETC_MSG_SPEED_40G,
+	ENETC_MSG_SPEED_50G,
+	ENETC_MSG_SPEED_100G,
+};
+
 struct enetc_msg_swbd {
 	void *vaddr;
 	dma_addr_t dma;
@@ -179,6 +204,11 @@ struct enetc_msg_mac_exact_filter {
  * cmd_id 0x0: get the current link status
  * cmd_id 0x1: register link status change notification
  * cmd_id 0x2: unregister link status change notification
+ *
+ * Link speed message, class_id 0x81.
+ * cmd_id 0x0: get the current link speed.
+ * cmd_id 0x1: register link speed change notification, not supported yet
+ * cmd_id 0x2: unregister link speed change notification, not supported yet
  */
 struct enetc_msg_generic {
 	struct enetc_msg_header hdr;
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_msg.c b/drivers/net/ethernet/freescale/enetc/enetc_msg.c
index eac71f90d80b..b24903b23a61 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_msg.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_msg.c
@@ -9,6 +9,9 @@
 					   ENETC_MSG_CLASS_ID_CMD_NOT_SUPPORT)
 #define ENETC_PF_MSG_PERM_DENY	FIELD_PREP(ENETC_PF_MSG_CLASS_ID, \
 					   ENETC_MSG_CLASS_ID_PERMISSION_DENY)
+#define ENETC_PF_MSG_SPEED(s)	(FIELD_PREP(ENETC_PF_MSG_CLASS_ID, \
+					    ENETC_MSG_CLASS_ID_LINK_SPEED) | \
+				 FIELD_PREP(ENETC_PF_MSG_CLASS_CODE, (s)))
 
 static void enetc_msg_disable_mr_int(struct enetc_pf *pf)
 {
@@ -274,6 +277,84 @@ static u16 enetc_msg_handle_link_status(struct enetc_pf *pf, int vf_id,
 	}
 }
 
+static u16 enetc_msg_get_link_speed(struct enetc_pf *pf, int vf_id)
+{
+	struct enetc_ndev_priv *priv = netdev_priv(pf->si->ndev);
+	struct enetc_vf_state *vf_state = &pf->vf_state[vf_id];
+	struct ethtool_link_ksettings link_info = {};
+
+	/* A malicious or malfunctioning VM could potentially spam these
+	 * messages in a tight loop causing global rtnl_lock contention,
+	 * which may severely starve other processes on the host that
+	 * require rtnl_lock for routine network configuration, resulting
+	 * in a system-wide control-plane denial of service. Therefore,
+	 * we expect the VF query for link speed to be trusted. There's no
+	 * need to consider the transition from trusted to untrusted here,
+	 * as this won't cause rntl_lock() to be called frequently.
+	 */
+	mutex_lock(&vf_state->lock);
+	if (!(vf_state->flags & ENETC_VF_FLAG_TRUSTED)) {
+		mutex_unlock(&vf_state->lock);
+
+		return ENETC_PF_MSG_PERM_DENY;
+	}
+	mutex_unlock(&vf_state->lock);
+
+	rtnl_lock();
+	phylink_ethtool_ksettings_get(priv->phylink, &link_info);
+	rtnl_unlock();
+
+	switch (link_info.base.speed) {
+	case SPEED_10:
+		if (link_info.base.duplex == DUPLEX_HALF)
+			return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_10M_HD);
+		else if (link_info.base.duplex == DUPLEX_FULL)
+			return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_10M_FD);
+		else
+			return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_UNKNOWN);
+	case SPEED_100:
+		if (link_info.base.duplex == DUPLEX_HALF)
+			return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_100M_HD);
+		else if (link_info.base.duplex == DUPLEX_FULL)
+			return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_100M_FD);
+		else
+			return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_UNKNOWN);
+	case SPEED_1000:
+		return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_1000M);
+	case SPEED_2500:
+		return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_2500M);
+	case SPEED_5000:
+		return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_5G);
+	case SPEED_10000:
+		return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_10G);
+	case SPEED_25000:
+		return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_25G);
+	case SPEED_40000:
+		return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_40G);
+	case SPEED_50000:
+		return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_50G);
+	case SPEED_100000:
+		return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_100G);
+	default:
+		return ENETC_PF_MSG_SPEED(ENETC_MSG_SPEED_UNKNOWN);
+	}
+}
+
+static u16 enetc_msg_handle_link_speed(struct enetc_pf *pf, int vf_id,
+				       void *vf_msg)
+{
+	struct enetc_msg_header *msg_hdr = vf_msg;
+
+	switch (msg_hdr->cmd_id) {
+	case ENETC_MSG_GET_CURRENT_LINK_SPEED:
+		return enetc_msg_get_link_speed(pf, vf_id);
+	case ENETC_MSG_REGISTER_SPEED_CHANGE_NOTIFIER:
+	case ENETC_MSG_UNREGISTER_SPEED_CHANGE_NOTIFIER:
+	default:
+		return ENETC_PF_MSG_NOTSUPP;
+	}
+}
+
 /* If *pf_msg is set to 0, it means that PF has responded to VF in
  * enetc_msg_handle_rxmsg() through enetc_pf_reply_msg(), which also
  * clears the corresponding VF MR bit in PSIIDR.
@@ -356,6 +437,9 @@ static void enetc_msg_handle_rxmsg(struct enetc_pf *pf, int vf_id,
 	case ENETC_MSG_CLASS_ID_LINK_STATUS:
 		*pf_msg = enetc_msg_handle_link_status(pf, vf_id, msg);
 		break;
+	case ENETC_MSG_CLASS_ID_LINK_SPEED:
+		*pf_msg = enetc_msg_handle_link_speed(pf, vf_id, msg);
+		break;
 	default:
 		dev_err_ratelimited(dev,
 				    "Unsupported message class ID: 0x%x\n",
@@ -540,6 +624,7 @@ int enetc_sriov_configure(struct pci_dev *pdev, int num_vfs)
 			dev_err(&pdev->dev, "pci_enable_sriov err %d\n", err);
 			goto err_en_sriov;
 		}
+
 	}
 
 	return num_vfs;
-- 
2.34.1