net/ncsi: Add NCSI OEM command support

This patch adds OEM commands and response handling. It also defines OEM
command and response structure as per NCSI specification along with its
handlers.

ncsi_cmd_handler_oem: This is a generic command request handler for OEM
commands
ncsi_rsp_handler_oem: This is a generic response handler for OEM commands

Signed-off-by: Vijay Khemka <vijaykhemka@fb.com>
Reviewed-by: Justin Lee <justin.lee1@dell.com>
Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ncsi/internal.h

@@ -68,6 +68,10 @@ enum {
 	NCSI_MODE_MAX
 };
 
+/* OEM Vendor Manufacture ID */
+#define NCSI_OEM_MFR_MLX_ID             0x8119
+#define NCSI_OEM_MFR_BCM_ID             0x113d
+
 struct ncsi_channel_version {
 	u32 version;		/* Supported BCD encoded NCSI version */
 	u32 alpha2;		/* Supported BCD encoded NCSI version */
@@ -305,6 +309,7 @@ struct ncsi_cmd_arg {
 		unsigned short words[8];
 		unsigned int   dwords[4];
 	};
+	unsigned char        *data;       /* NCSI OEM data                 */
 };
 
 extern struct list_head ncsi_dev_list;

net/ncsi/ncsi-cmd.c

@@ -211,6 +211,25 @@ static int ncsi_cmd_handler_snfc(struct sk_buff *skb,
 	return 0;
 }
 
+static int ncsi_cmd_handler_oem(struct sk_buff *skb,
+				struct ncsi_cmd_arg *nca)
+{
+	struct ncsi_cmd_oem_pkt *cmd;
+	unsigned int len;
+
+	len = sizeof(struct ncsi_cmd_pkt_hdr) + 4;
+	if (nca->payload < 26)
+		len += 26;
+	else
+		len += nca->payload;
+
+	cmd = skb_put_zero(skb, len);
+	memcpy(&cmd->mfr_id, nca->data, nca->payload);
+	ncsi_cmd_build_header(&cmd->cmd.common, nca);
+
+	return 0;
+}
+
 static struct ncsi_cmd_handler {
 	unsigned char type;
 	int           payload;
@@ -244,7 +263,7 @@ static struct ncsi_cmd_handler {
 	{ NCSI_PKT_CMD_GNS,    0, ncsi_cmd_handler_default },
 	{ NCSI_PKT_CMD_GNPTS,  0, ncsi_cmd_handler_default },
 	{ NCSI_PKT_CMD_GPS,    0, ncsi_cmd_handler_default },
-	{ NCSI_PKT_CMD_OEM,    0, NULL                     },
+	{ NCSI_PKT_CMD_OEM,   -1, ncsi_cmd_handler_oem     },
 	{ NCSI_PKT_CMD_PLDM,   0, NULL                     },
 	{ NCSI_PKT_CMD_GPUUID, 0, ncsi_cmd_handler_default }
 };
@@ -316,8 +335,13 @@ int ncsi_xmit_cmd(struct ncsi_cmd_arg *nca)
 		return -ENOENT;
 	}
 
-	/* Get packet payload length and allocate the request */
-	nca->payload = nch->payload;
+	/* Get packet payload length and allocate the request
+	 * It is expected that if length set as negative in
+	 * handler structure means caller is initializing it
+	 * and setting length in nca before calling xmit function
+	 */
+	if (nch->payload >= 0)
+		nca->payload = nch->payload;
 	nr = ncsi_alloc_command(nca);
 	if (!nr)
 		return -ENOMEM;

net/ncsi/ncsi-pkt.h

@@ -151,6 +151,20 @@ struct ncsi_cmd_snfc_pkt {
 	unsigned char           pad[22];
 };
 
+/* OEM Request Command as per NCSI Specification */
+struct ncsi_cmd_oem_pkt {
+	struct ncsi_cmd_pkt_hdr cmd;         /* Command header    */
+	__be32                  mfr_id;      /* Manufacture ID    */
+	unsigned char           data[];      /* OEM Payload Data  */
+};
+
+/* OEM Response Packet as per NCSI Specification */
+struct ncsi_rsp_oem_pkt {
+	struct ncsi_rsp_pkt_hdr rsp;         /* Command header    */
+	__be32                  mfr_id;      /* Manufacture ID    */
+	unsigned char           data[];      /* Payload data      */
+};
+
 /* Get Link Status */
 struct ncsi_rsp_gls_pkt {
 	struct ncsi_rsp_pkt_hdr rsp;        /* Response header   */

net/ncsi/ncsi-rsp.c

@@ -596,6 +596,47 @@ static int ncsi_rsp_handler_snfc(struct ncsi_request *nr)
 	return 0;
 }
 
+static struct ncsi_rsp_oem_handler {
+	unsigned int	mfr_id;
+	int		(*handler)(struct ncsi_request *nr);
+} ncsi_rsp_oem_handlers[] = {
+	{ NCSI_OEM_MFR_MLX_ID, NULL },
+	{ NCSI_OEM_MFR_BCM_ID, NULL }
+};
+
+/* Response handler for OEM command */
+static int ncsi_rsp_handler_oem(struct ncsi_request *nr)
+{
+	struct ncsi_rsp_oem_pkt *rsp;
+	struct ncsi_rsp_oem_handler *nrh = NULL;
+	unsigned int mfr_id, i;
+
+	/* Get the response header */
+	rsp = (struct ncsi_rsp_oem_pkt *)skb_network_header(nr->rsp);
+	mfr_id = ntohl(rsp->mfr_id);
+
+	/* Check for manufacturer id and Find the handler */
+	for (i = 0; i < ARRAY_SIZE(ncsi_rsp_oem_handlers); i++) {
+		if (ncsi_rsp_oem_handlers[i].mfr_id == mfr_id) {
+			if (ncsi_rsp_oem_handlers[i].handler)
+				nrh = &ncsi_rsp_oem_handlers[i];
+			else
+				nrh = NULL;
+
+			break;
+		}
+	}
+
+	if (!nrh) {
+		netdev_err(nr->ndp->ndev.dev, "Received unrecognized OEM packet with MFR-ID (0x%x)\n",
+			   mfr_id);
+		return -ENOENT;
+	}
+
+	/* Process the packet */
+	return nrh->handler(nr);
+}
+
 static int ncsi_rsp_handler_gvi(struct ncsi_request *nr)
 {
 	struct ncsi_rsp_gvi_pkt *rsp;
@@ -932,7 +973,7 @@ static struct ncsi_rsp_handler {
 	{ NCSI_PKT_RSP_GNS,   172, ncsi_rsp_handler_gns     },
 	{ NCSI_PKT_RSP_GNPTS, 172, ncsi_rsp_handler_gnpts   },
 	{ NCSI_PKT_RSP_GPS,     8, ncsi_rsp_handler_gps     },
-	{ NCSI_PKT_RSP_OEM,     0, NULL                     },
+	{ NCSI_PKT_RSP_OEM,    -1, ncsi_rsp_handler_oem     },
 	{ NCSI_PKT_RSP_PLDM,    0, NULL                     },
 	{ NCSI_PKT_RSP_GPUUID, 20, ncsi_rsp_handler_gpuuid  }
 };