1) Create net device & implement net operations for data/IP communication.
2) Bind IP Link to mux IP session for simultaneous IP traffic.
Signed-off-by: M Chetan Kumar <m.chetan.kumar@xxxxxxxxx>
---
v2:
* Removed Ethernet header & VLAN tag handling from wwan net driver.
* Implement rtnet_link interface for IP traffic handling.
---
drivers/net/wwan/iosm/iosm_ipc_wwan.c | 445 ++++++++++++++++++++++++++
drivers/net/wwan/iosm/iosm_ipc_wwan.h | 55 ++++
2 files changed, 500 insertions(+)
create mode 100644 drivers/net/wwan/iosm/iosm_ipc_wwan.c
create mode 100644 drivers/net/wwan/iosm/iosm_ipc_wwan.h
diff --git a/drivers/net/wwan/iosm/iosm_ipc_wwan.c b/drivers/net/wwan/iosm/iosm_ipc_wwan.c
new file mode 100644
index 000000000000..cf721bcbddce
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_wwan.c
@@ -0,0 +1,445 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_link.h>
+#include <net/rtnetlink.h>
+
+#include "iosm_ipc_chnl_cfg.h"
+#include "iosm_ipc_imem_ops.h"
+#include "iosm_ipc_wwan.h"
+
+#define IOSM_IP_TYPE_MASK 0xF0
+#define IOSM_IP_TYPE_IPV4 0x40
+#define IOSM_IP_TYPE_IPV6 0x60
+
+#define IOSM_IF_ID_PAYLOAD 2
+
+static struct device_type wwan_type = { .name = "wwan" };
+
+static const struct nla_policy iosm_wwan_policy[IFLA_IOSM_MAX + 1] = {
+ [IFLA_IOSM_IF_ID] = { .type = NLA_U16 },
+};
+
+/**
+ * struct iosm_net_link - This structure includes information about interface dev.
+ * @if_id: Interface id for device.
+ * @ch_id: IPC channel number for which interface device is created.
+ * @netdev: Pointer to network interface device structure
+ * @ipc_wwan: Pointer to iosm_wwan struct
+ */
+
+struct iosm_net_link {
+ int if_id;
+ int ch_id;
+ struct net_device *netdev;
+ struct iosm_wwan *ipc_wwan;
+};
+
+/**
+ * struct iosm_wwan - This structure contains information about WWAN root device
+ * and interface to the IPC layer.
+ * @netdev: Pointer to network interface device structure.
+ * @sub_netlist: List of netlink interfaces
+ * @ipc_imem: Pointer to imem data-struct
+ * @dev: Pointer device structure
+ * @if_mutex: Mutex used for add and remove interface id
+ * @is_registered: Registration status with netdev
+ */
+struct iosm_wwan {
+ struct net_device *netdev;
+ struct iosm_net_link __rcu *sub_netlist[MAX_NET_SESSION];
+ struct iosm_imem *ipc_imem;
+ struct device *dev;
+ struct mutex if_mutex; /* Mutex used for add and remove interface id */
+ u8 is_registered:1;
+};
+
+/* Bring-up the wwan net link */
+static int iosm_wwan_link_open(struct net_device *netdev)
+{
+ struct iosm_net_link *netlink = netdev_priv(netdev);
+ struct iosm_wwan *ipc_wwan = netlink->ipc_wwan;
+ int if_id = netlink->if_id;
+ int ret = -EINVAL;
+
+ if ((if_id < IP_MUX_SESSION_START || if_id > IP_MUX_SESSION_END) &&
+ (if_id < DSS_CHANNEL_START || if_id > DSS_CHANNEL_END))
+ return ret;
+
+ mutex_lock(&ipc_wwan->if_mutex);
+
+ /* get channel id */
+ netlink->ch_id =
+ imem_sys_wwan_open(ipc_wwan->ipc_imem, if_id);
+
+ if (netlink->ch_id < 0) {
+ dev_err(ipc_wwan->dev,
+ "cannot connect wwan0 & id %d to the IPC mem layer",
+ if_id);
+ ret = -ENODEV;
+ goto out;
+ }
+
+ /* enable tx path, DL data may follow */
+ netif_start_queue(netdev);
+
+ dev_dbg(ipc_wwan->dev, "Channel id %d allocated to if_id %d",
+ netlink->ch_id, netlink->if_id);
+
+ ret = 0;
+out:
+ mutex_unlock(&ipc_wwan->if_mutex);
+ return ret;
+}
+
+/* Bring-down the wwan net link */
+static int iosm_wwan_link_stop(struct net_device *netdev)
+{
+ struct iosm_net_link *netlink = netdev_priv(netdev);
+
+ netif_stop_queue(netdev);
+
+ mutex_lock(&netlink->ipc_wwan->if_mutex);
+ imem_sys_wwan_close(netlink->ipc_wwan->ipc_imem, netlink->if_id,
+ netlink->ch_id);
+ mutex_unlock(&netlink->ipc_wwan->if_mutex);
+
+ return 0;
+}
+
+/* Transmit a packet */
+static int iosm_wwan_link_transmit(struct sk_buff *skb,
+ struct net_device *netdev)
+{
+ struct iosm_net_link *netlink = netdev_priv(netdev);
+ struct iosm_wwan *ipc_wwan = netlink->ipc_wwan;
+ int if_id = netlink->if_id;
+ int ret = -EINVAL;
+
+ /* Interface IDs from 1 to 8 are for IP data
+ * & from 257 to 261 are for non-IP data
+ */
+ if ((if_id < IP_MUX_SESSION_START || if_id > IP_MUX_SESSION_END) &&
+ (if_id < DSS_CHANNEL_START || if_id > DSS_CHANNEL_END))
+ goto exit;
+
+ /* Send the SKB to device for transmission */
+ ret = imem_sys_wwan_transmit(ipc_wwan->ipc_imem,
+ if_id, netlink->ch_id, skb);
+
+ /* Return code of zero is success */
+ if (ret == 0) {
+ ret = NETDEV_TX_OK;
+ } else if (ret == -EBUSY) {
+ ret = NETDEV_TX_BUSY;
+ dev_err(ipc_wwan->dev, "unable to push packets");
+ } else {
+ goto exit;
+ }
+
+ return ret;
+
+exit:
+ /* Log any skb drop */
+ if (if_id)
+ dev_dbg(ipc_wwan->dev, "skb dropped. IF_ID: %d, ret: %d", if_id,
+ ret);
+
+ dev_kfree_skb_any(skb);
+ return ret;
+}
+
+/* Ops structure for wwan net link */
+static const struct net_device_ops iosm_inm_ops = {
+ .ndo_open = iosm_wwan_link_open,
+ .ndo_stop = iosm_wwan_link_stop,
+ .ndo_start_xmit = iosm_wwan_link_transmit,
+};
+
+/* Setup function for creating new net link */
+static void iosm_wwan_setup(struct net_device *iosm_dev)
+{
+ iosm_dev->header_ops = NULL;
+ iosm_dev->hard_header_len = 0;
+ iosm_dev->priv_flags |= IFF_NO_QUEUE;
+
+ iosm_dev->type = ARPHRD_NONE;
+ iosm_dev->min_mtu = ETH_MIN_MTU;
+ iosm_dev->max_mtu = ETH_MAX_MTU;
+
+ iosm_dev->flags = IFF_POINTOPOINT | IFF_NOARP;
+
+ iosm_dev->netdev_ops = &iosm_inm_ops;
+}
+
+static struct device_type inm_type = { .name = "iosmdev" };
+
+/* Create new wwan net link */
+static int iosm_wwan_newlink(struct net *src_net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ struct iosm_net_link *netlink = netdev_priv(dev);
+ struct iosm_wwan *ipc_wwan;
+ struct net_device *netdev;
+ int err = -EINVAL;
+ int index;
+
+ if (!data[IFLA_IOSM_IF_ID]) {
+ pr_err("Interface ID not specified");
+ goto out;
+ }
+
+ if (!tb[IFLA_LINK]) {
+ pr_err("Link not specified");
+ goto out;
+ }
+
+ netlink->netdev = dev;
+
+ netdev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
+
+ netlink->ipc_wwan = netdev_priv(netdev);
+
+ ipc_wwan = netlink->ipc_wwan;
+
+ if (ipc_wwan->netdev != netdev)
+ goto out;
+
+ netlink->if_id = nla_get_u16(data[IFLA_IOSM_IF_ID]);
+ index = netlink->if_id;
+
+ /* Complete all memory stores before this point */
+ smp_mb();
+ if (index >= DSS_SESSION_START && index <= DSS_SESSION_END)
+ index = (index - DSS_SESSION_START) + IP_MUX_SESSION_END + 1;
+ else if ((index < IP_MUX_SESSION_START || index > IP_MUX_SESSION_END) &&
+ (index < DSS_SESSION_START || index > DSS_SESSION_END))
+ goto out;
+
+ rcu_read_lock();
+
+ if (rcu_access_pointer(ipc_wwan->sub_netlist[index - 1])) {
+ pr_err("IOSM interface ID already in use");
+ goto out_free_lock;
+ }
+
+ SET_NETDEV_DEVTYPE(dev, &inm_type);
+
+ eth_hw_addr_random(dev);
+ err = register_netdevice(dev);
+ if (err) {
+ dev_err(ipc_wwan->dev, "register netlink failed.\n");
+ goto out_free_lock;
+ }
+
+ err = netdev_upper_dev_link(ipc_wwan->netdev, dev, extack);
+
+ if (err) {
+ dev_err(ipc_wwan->dev, "netdev linking with parent failed.\n");
+ goto netlink_err;
+ }
+
+ rcu_assign_pointer(ipc_wwan->sub_netlist[index - 1], netlink);
+ netif_device_attach(dev);
+ rcu_read_unlock();
+
+ return 0;
+
+netlink_err:
+ unregister_netdevice(dev);
+out_free_lock:
+ rcu_read_unlock();
+out:
+ return err;
+}
+
+/* Delete new wwan net link */
+static void iosm_wwan_dellink(struct net_device *dev, struct list_head *head)
+{
+ struct iosm_net_link *netlink = netdev_priv(dev);
+ u16 index = netlink->if_id;
+
+ netdev_upper_dev_unlink(netlink->ipc_wwan->netdev, dev);
+ unregister_netdevice(dev);
+
+ if (index >= DSS_SESSION_START && index <= DSS_SESSION_END)
+ index = (index - DSS_SESSION_START) + IP_MUX_SESSION_END + 1;
+
+ mutex_lock(&netlink->ipc_wwan->if_mutex);
+ rcu_assign_pointer(netlink->ipc_wwan->sub_netlist[index - 1], NULL);
+ mutex_unlock(&netlink->ipc_wwan->if_mutex);
+}
+
+/* Get size for iosm net link payload*/
+static size_t iosm_wwan_get_size(const struct net_device *dev)
+{
+ return nla_total_size(IOSM_IF_ID_PAYLOAD);
+}
+
+/* Validate the input parameters for wwan net link */
+static int iosm_wwan_validate(struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ u16 if_id;
+
+ if (!data || !data[IFLA_IOSM_IF_ID]) {
+ NL_SET_ERR_MSG_MOD(extack, "IF ID not specified");
+ return -EINVAL;
+ }
+
+ if_id = nla_get_u16(data[IFLA_IOSM_IF_ID]);
+
+ if ((if_id < IP_MUX_SESSION_START || if_id > IP_MUX_SESSION_END) &&
+ (if_id < DSS_SESSION_START || if_id > DSS_SESSION_END)) {
+ NL_SET_ERR_MSG_MOD(extack, "Invalid Interface");
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+/* RT Net link ops structure for new wwan net link */
+struct rtnl_link_ops iosm_netlink __read_mostly = {
+ .kind = "iosm",
+ .maxtype = __IFLA_IOSM_MAX,
+ .priv_size = sizeof(struct iosm_net_link),
+ .setup = iosm_wwan_setup,
+ .validate = iosm_wwan_validate,
+ .newlink = iosm_wwan_newlink,
+ .dellink = iosm_wwan_dellink,
+ .get_size = iosm_wwan_get_size,
+ .policy = iosm_wwan_policy,
+};
+
+int ipc_wwan_receive(struct iosm_wwan *ipc_wwan, struct sk_buff *skb_arg,
+ bool dss, int if_id)
+{
+ struct sk_buff *skb = skb_arg;
+ struct net_device_stats stats;
+ int ret;
+
+ if ((skb->data[0] & IOSM_IP_TYPE_MASK) == IOSM_IP_TYPE_IPV4)
+ skb->protocol = htons(ETH_P_IP);
+ else if ((skb->data[0] & IOSM_IP_TYPE_MASK) ==
+ IOSM_IP_TYPE_IPV6)
+ skb->protocol = htons(ETH_P_IPV6);
+
+ skb->pkt_type = PACKET_HOST;
+
+ if (if_id < (NET_SESSION_START - 1) || if_id > (MAX_NET_SESSION - 1)) {
+ dev_kfree_skb(skb);
+ return -EINVAL;
+ }
+
+ rcu_read_lock();
+ skb->dev = rcu_dereference(ipc_wwan->sub_netlist[if_id])->netdev;
+ stats = rcu_dereference(ipc_wwan->sub_netlist[if_id])->netdev->stats;
+ stats.rx_packets++;
+ stats.rx_bytes += skb->len;
+
+ ret = netif_rx(skb);
+ rcu_read_unlock();
+
+ return ret;
+}
+
+void ipc_wwan_tx_flowctrl(struct iosm_wwan *ipc_wwan, int if_id, bool on)
+{
+ struct net_device *netdev;
+ bool is_tx_blk;
+
+ rcu_read_lock();
+ netdev = rcu_dereference(ipc_wwan->sub_netlist[if_id])->netdev;
+
+ is_tx_blk = netif_queue_stopped(netdev);
+
+ if (on)
+ dev_dbg(ipc_wwan->dev, "session id[%d]: flowctrl enable",
+ if_id);
+
+ if (on && !is_tx_blk)
+ netif_stop_queue(netdev);
+ else if (!on && is_tx_blk)
+ netif_wake_queue(netdev);
+ rcu_read_unlock();
+}
+
+static void iosm_netdev_setup(struct net_device *dev) {}
+
+struct iosm_wwan *ipc_wwan_init(struct iosm_imem *ipc_imem, struct device *dev)
+{
+ static const struct net_device_ops iosm_wwandev_ops = {};
+ struct iosm_wwan *ipc_wwan;
+ struct net_device *netdev;
+
+ netdev = alloc_netdev(sizeof(*ipc_wwan), "wwan%d", NET_NAME_ENUM,
+ iosm_netdev_setup);
+
+ if (!netdev)
+ return NULL;
+
+ ipc_wwan = netdev_priv(netdev);
+
+ ipc_wwan->dev = dev;
+ ipc_wwan->netdev = netdev;
+ ipc_wwan->is_registered = false;
+
+ ipc_wwan->ipc_imem = ipc_imem;
+
+ mutex_init(&ipc_wwan->if_mutex);
+
+ /* allocate random ethernet address */
+ eth_random_addr(netdev->dev_addr);
+ netdev->addr_assign_type = NET_ADDR_RANDOM;
+
+ netdev->netdev_ops = &iosm_wwandev_ops;
+ netdev->flags |= IFF_NOARP;
+
+ SET_NETDEV_DEVTYPE(netdev, &wwan_type);
+
+ if (register_netdev(netdev)) {
+ dev_err(ipc_wwan->dev, "register_netdev failed");
+ goto reg_fail;
+ }
+
+ ipc_wwan->is_registered = true;
+
+ netif_device_attach(netdev);
+
+ return ipc_wwan;
+
+reg_fail:
+ free_netdev(netdev);
+ return NULL;
+}
+
+void ipc_wwan_deinit(struct iosm_wwan *ipc_wwan)
+{
+ struct iosm_net_link *netlink;
+ int i;
+
+ if (ipc_wwan->is_registered) {
+ rcu_read_lock();
+ for (i = IP_MUX_SESSION_START; i <= IP_DSS_SESSION_END; i++) {
+ if (rcu_access_pointer(ipc_wwan->sub_netlist[i - 1])) {
+ netlink =
+ rcu_dereference(ipc_wwan->sub_netlist[i - 1]);
+ rtnl_lock();
+ netdev_upper_dev_unlink(ipc_wwan->netdev,
+ netlink->netdev);
+ unregister_netdevice(netlink->netdev);
+ rtnl_unlock();
+ rcu_assign_pointer(ipc_wwan->sub_netlist[i - 1], NULL);
+ }
+ }
+ rcu_read_unlock();
+
+ unregister_netdev(ipc_wwan->netdev);
+ free_netdev(ipc_wwan->netdev);
+ }
+}
diff --git a/drivers/net/wwan/iosm/iosm_ipc_wwan.h b/drivers/net/wwan/iosm/iosm_ipc_wwan.h
new file mode 100644
index 000000000000..4925f22dff0a
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_wwan.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#ifndef IOSM_IPC_WWAN_H
+#define IOSM_IPC_WWAN_H
+
+/**
+ * ipc_wwan_init - Allocate, Init and register WWAN device
+ * @ipc_imem: Pointer to imem data-struct
+ * @dev: Pointer to device structure
+ *
+ * Returns: Pointer to instance on success else NULL
+ */
+struct iosm_wwan *ipc_wwan_init(struct iosm_imem *ipc_imem, struct device *dev);
+
+/**
+ * ipc_wwan_deinit - Unregister and free WWAN device, clear pointer
+ * @ipc_wwan: Pointer to wwan instance data
+ */
+void ipc_wwan_deinit(struct iosm_wwan *ipc_wwan);
+
+/**
+ * ipc_wwan_receive - Receive a downlink packet from CP.
+ * @ipc_wwan: Pointer to wwan instance
+ * @skb_arg: Pointer to struct sk_buff
+ * @dss: Set to true if interafce id is from 257 to 261,
+ * else false
+ * @if_id: Interface ID
+ *
+ * Return: 0 on success and failure value on error
+ */
+int ipc_wwan_receive(struct iosm_wwan *ipc_wwan, struct sk_buff *skb_arg,
+ bool dss, int if_id);
+
+/**
+ * ipc_wwan_tx_flowctrl - Enable/Disable TX flow control
+ * @ipc_wwan: Pointer to wwan instance
+ * @id: Ipc mux channel session id
+ * @on: if true then flow ctrl would be enabled else disable
+ *
+ */
+void ipc_wwan_tx_flowctrl(struct iosm_wwan *ipc_wwan, int id, bool on);
+
+/**
+ * ipc_wwan_is_tx_stopped - Checks if Tx stopped for a Interface id.
+ * @ipc_wwan: Pointer to wwan instance
+ * @id: Ipc mux channel session id
+ *
+ * Return: true if stopped, false otherwise
+ */
+bool ipc_wwan_is_tx_stopped(struct iosm_wwan *ipc_wwan, int id);
+
+#endif
--
2.25.1
