drivers: net: ethernet: qualcomm: rmnet: Initial implementation

RmNet driver provides a transport agnostic MAP (multiplexing and
aggregation protocol) support in embedded module. Module provides
virtual network devices which can be attached to any IP-mode
physical device. This will be used to provide all MAP functionality
on future hardware in a single consistent location.

Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 107 insertions, 0 deletions

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c
new file mode 100644
index 000000000000..ccded40ee551
--- /dev/null
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c
@@ -0,0 +1,107 @@
+/* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/netdevice.h>
+#include "rmnet_config.h"
+#include "rmnet_map.h"
+#include "rmnet_private.h"
+#include "rmnet_vnd.h"
+
+static u8 rmnet_map_do_flow_control(struct sk_buff *skb,
+				    struct rmnet_real_dev_info *rdinfo,
+				    int enable)
+{
+	struct rmnet_map_control_command *cmd;
+	struct rmnet_endpoint *ep;
+	struct net_device *vnd;
+	u16 ip_family;
+	u16 fc_seq;
+	u32 qos_id;
+	u8 mux_id;
+	int r;
+
+	mux_id = RMNET_MAP_GET_MUX_ID(skb);
+	cmd = RMNET_MAP_GET_CMD_START(skb);
+
+	if (mux_id >= RMNET_MAX_LOGICAL_EP) {
+		kfree_skb(skb);
+		return RX_HANDLER_CONSUMED;
+	}
+
+	ep = &rdinfo->muxed_ep[mux_id];
+	vnd = ep->egress_dev;
+
+	ip_family = cmd->flow_control.ip_family;
+	fc_seq = ntohs(cmd->flow_control.flow_control_seq_num);
+	qos_id = ntohl(cmd->flow_control.qos_id);
+
+	/* Ignore the ip family and pass the sequence number for both v4 and v6
+	 * sequence. User space does not support creating dedicated flows for
+	 * the 2 protocols
+	 */
+	r = rmnet_vnd_do_flow_control(vnd, enable);
+	if (r) {
+		kfree_skb(skb);
+		return RMNET_MAP_COMMAND_UNSUPPORTED;
+	} else {
+		return RMNET_MAP_COMMAND_ACK;
+	}
+}
+
+static void rmnet_map_send_ack(struct sk_buff *skb,
+			       unsigned char type,
+			       struct rmnet_real_dev_info *rdinfo)
+{
+	struct rmnet_map_control_command *cmd;
+	int xmit_status;
+
+	skb->protocol = htons(ETH_P_MAP);
+
+	cmd = RMNET_MAP_GET_CMD_START(skb);
+	cmd->cmd_type = type & 0x03;
+
+	netif_tx_lock(skb->dev);
+	xmit_status = skb->dev->netdev_ops->ndo_start_xmit(skb, skb->dev);
+	netif_tx_unlock(skb->dev);
+}
+
+/* Process MAP command frame and send N/ACK message as appropriate. Message cmd
+ * name is decoded here and appropriate handler is called.
+ */
+rx_handler_result_t rmnet_map_command(struct sk_buff *skb,
+				      struct rmnet_real_dev_info *rdinfo)
+{
+	struct rmnet_map_control_command *cmd;
+	unsigned char command_name;
+	unsigned char rc = 0;
+
+	cmd = RMNET_MAP_GET_CMD_START(skb);
+	command_name = cmd->command_name;
+
+	switch (command_name) {
+	case RMNET_MAP_COMMAND_FLOW_ENABLE:
+		rc = rmnet_map_do_flow_control(skb, rdinfo, 1);
+		break;
+
+	case RMNET_MAP_COMMAND_FLOW_DISABLE:
+		rc = rmnet_map_do_flow_control(skb, rdinfo, 0);
+		break;
+
+	default:
+		rc = RMNET_MAP_COMMAND_UNSUPPORTED;
+		kfree_skb(skb);
+		break;
+	}
+	if (rc == RMNET_MAP_COMMAND_ACK)
+		rmnet_map_send_ack(skb, rc, rdinfo);
+	return RX_HANDLER_CONSUMED;
+}