net/ncsi: add NCSI Intel OEM command to keep PHY up

This allows to keep PHY link up and prevents any channel resets during
the host load.

It is KEEP_PHY_LINK_UP option(Veto bit) in i210 datasheet which
block PHY reset and power state changes.

Signed-off-by: Ivan Mikhaylov <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/ncsi/Kconfig

···
 	help
 	  This allows to get MAC address from NCSI firmware and set them back to
 		controller.
+config NCSI_OEM_CMD_KEEP_PHY
+	bool "Keep PHY Link up"
+	depends on NET_NCSI
+	help
+	  This allows to keep PHY link up and prevents any channel resets during
+	  the host load.

net/ncsi/internal.h

···
 /* OEM Vendor Manufacture ID */
 #define NCSI_OEM_MFR_MLX_ID             0x8119
 #define NCSI_OEM_MFR_BCM_ID             0x113d
+#define NCSI_OEM_MFR_INTEL_ID           0x157
+/* Intel specific OEM command */
+#define NCSI_OEM_INTEL_CMD_KEEP_PHY     0x20   /* CMD ID for Keep PHY up */
 /* Broadcom specific OEM Command */
 #define NCSI_OEM_BCM_CMD_GMA            0x01   /* CMD ID for Get MAC */
 /* Mellanox specific OEM Command */
···
 #define NCSI_OEM_MLX_CMD_SMAF           0x01   /* CMD ID for Set MC Affinity */
 #define NCSI_OEM_MLX_CMD_SMAF_PARAM     0x07   /* Parameter for SMAF         */
 /* OEM Command payload lengths*/
+#define NCSI_OEM_INTEL_CMD_KEEP_PHY_LEN 7
 #define NCSI_OEM_BCM_CMD_GMA_LEN        12
 #define NCSI_OEM_MLX_CMD_GMA_LEN        8
 #define NCSI_OEM_MLX_CMD_SMAF_LEN        60
···
 	ncsi_dev_state_probe_mlx_gma,
 	ncsi_dev_state_probe_mlx_smaf,
 	ncsi_dev_state_probe_cis,
+	ncsi_dev_state_probe_keep_phy,
 	ncsi_dev_state_probe_gvi,
 	ncsi_dev_state_probe_gc,
 	ncsi_dev_state_probe_gls,

net/ncsi/ncsi-manage.c

···
 	return 0;
 }
 
+#if IS_ENABLED(CONFIG_NCSI_OEM_CMD_KEEP_PHY)
+
+static int ncsi_oem_keep_phy_intel(struct ncsi_cmd_arg *nca)
+{
+	unsigned char data[NCSI_OEM_INTEL_CMD_KEEP_PHY_LEN];
+	int ret = 0;
+
+	nca->payload = NCSI_OEM_INTEL_CMD_KEEP_PHY_LEN;
+
+	memset(data, 0, NCSI_OEM_INTEL_CMD_KEEP_PHY_LEN);
+	*(unsigned int *)data = ntohl((__force __be32)NCSI_OEM_MFR_INTEL_ID);
+
+	data[4] = NCSI_OEM_INTEL_CMD_KEEP_PHY;
+
+	/* PHY Link up attribute */
+	data[6] = 0x1;
+
+	nca->data = data;
+
+	ret = ncsi_xmit_cmd(nca);
+	if (ret)
+		netdev_err(nca->ndp->ndev.dev,
+			   "NCSI: Failed to transmit cmd 0x%x during configure\n",
+			   nca->type);
+	return ret;
+}
+
+#endif
+
 #if IS_ENABLED(CONFIG_NCSI_OEM_CMD_GET_MAC)
 
 /* NCSI OEM Command APIs */
···
 		}
 
 		nd->state = ncsi_dev_state_probe_gvi;
+		if (IS_ENABLED(CONFIG_NCSI_OEM_CMD_KEEP_PHY))
+			nd->state = ncsi_dev_state_probe_keep_phy;
 		break;
+#if IS_ENABLED(CONFIG_NCSI_OEM_CMD_KEEP_PHY)
+	case ncsi_dev_state_probe_keep_phy:
+		ndp->pending_req_num = 1;
+
+		nca.type = NCSI_PKT_CMD_OEM;
+		nca.package = ndp->active_package->id;
+		nca.channel = 0;
+		ret = ncsi_oem_keep_phy_intel(&nca);
+		if (ret)
+			goto error;
+
+		nd->state = ncsi_dev_state_probe_gvi;
+		break;
+#endif /* CONFIG_NCSI_OEM_CMD_KEEP_PHY */
 	case ncsi_dev_state_probe_gvi:
 	case ncsi_dev_state_probe_gc:
 	case ncsi_dev_state_probe_gls: