// 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 <linux/rtnetlink.h>
#include <linux/wwan.h>
#include <net/pkt_sched.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
/**
* struct iosm_netdev_priv - netdev WWAN driver specific private data
* @ipc_wwan: Pointer to iosm_wwan struct
* @netdev: Pointer to network interface device structure
* @if_id: Interface id for device.
* @ch_id: IPC channel number for which interface device is created.
*/
struct iosm_netdev_priv {
struct iosm_wwan *ipc_wwan;
struct net_device *netdev;
int if_id;
int ch_id;
};
/**
* struct iosm_wwan - This structure contains information about WWAN root device
* and interface to the IPC layer.
* @ipc_imem: Pointer to imem data-struct
* @sub_netlist: List of active netdevs
* @dev: Pointer device structure
*/
struct iosm_wwan {
struct iosm_imem *ipc_imem;
struct iosm_netdev_priv __rcu *sub_netlist[IP_MUX_SESSION_END + 1];
struct device *dev;
};
/* Bring-up the wwan net link */
static int ipc_wwan_link_open(struct net_device *netdev)
{
struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev);
struct iosm_wwan *ipc_wwan = priv->ipc_wwan;
int if_id = priv->if_id;
if (if_id < IP_MUX_SESSION_START ||
if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist))
return -EINVAL;
/* get channel id */
priv->ch_id = ipc_imem_sys_wwan_open(ipc_wwan->ipc_imem, if_id);
if (priv->ch_id < 0) {
dev_err(ipc_wwan->dev,
"cannot connect wwan0 & id %d to the IPC mem layer",
if_id);
return -ENODEV;
}
/* enable tx path, DL data may follow */
netif_start_queue(netdev);
dev_dbg(ipc_wwan->dev, "Channel id %d allocated to if_id %d",
priv->ch_id, priv->if_id);
return 0;
}
/* Bring-down the wwan net link */
static int ipc_wwan_link_stop(struct net_device *netdev)
{
struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev);
netif_stop_queue(netdev);
ipc_imem_sys_wwan_close(priv->ipc_wwan->ipc_imem, priv->if_id,
priv->ch_id);
priv->ch_id = -1;
return 0;
}
/* Transmit a packet */
static netdev_tx_t ipc_wwan_link_transmit(struct sk_buff *skb,
struct net_device *netdev)
{
struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev);
struct iosm_wwan *ipc_wwan = priv->ipc_wwan;
unsigned int len = skb->len;
int if_id = priv->if_id;
int ret;
/* 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 >= ARRAY_SIZE(ipc_wwan->sub_netlist))
return -EINVAL;
/* Send the SKB to device for transmission */
ret = ipc_imem_sys_wwan_transmit(ipc_wwan->ipc_imem,
if_id, priv->ch_id, skb);
/* Return code of zero is success */
if (ret == 0) {
netdev->stats.tx_packets++;
netdev->stats.tx_bytes += len;
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);
netdev->stats.tx_dropped++;
return NETDEV_TX_OK;
}
/* Ops structure for wwan net link */
static const struct net_device_ops ipc_inm_ops = {
.ndo_open = ipc_wwan_link_open,
.ndo_stop = ipc_wwan_link_stop,
.ndo_start_xmit = ipc_wwan_link_transmit,
};
/* Setup function for creating new net link */
static void ipc_wwan_setup(struct net_device *iosm_dev)
{
iosm_dev->header_ops = NULL;
iosm_dev->hard_header_len = 0;
iosm_dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
iosm_dev->type = ARPHRD_NONE;
iosm_dev->mtu = ETH_DATA_LEN;
iosm_dev->min_mtu = ETH_MIN_MTU;
iosm_dev->max_mtu = ETH_MAX_MTU;
iosm_dev->flags = IFF_POINTOPOINT | IFF_NOARP;
iosm_dev->needs_free_netdev = true;
iosm_dev->netdev_ops = &ipc_inm_ops;
}
/* Create new wwan net link */
static int ipc_wwan_newlink(void *ctxt, struct net_device *dev,
u32 if_id, struct netlink_ext_ack *extack)
{
struct iosm_wwan *ipc_wwan = ctxt;
struct iosm_netdev_priv *priv;
int err;
if (if_id < IP_MUX_SESSION_START ||
if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist))
return -EINVAL;
priv = wwan_netdev_drvpriv(dev);
priv->if_id = if_id;
priv->netdev = dev;
priv->ipc_wwan = ipc_wwan;
if (rcu_access_pointer(ipc_wwan->sub_netlist[if_id]))
return -EBUSY;
err = register_netdevice(dev);
if (err)
return err;
rcu_assign_pointer(ipc_wwan->sub_netlist[if_id], priv);
netif_device_attach(dev);
return 0;
}
static void ipc_wwan_dellink(void *ctxt, struct net_device *dev,
struct list_head *head)
{
struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(dev);
struct iosm_wwan *ipc_wwan = ctxt;
int if_id = priv->if_id;
if (WARN_ON(if_id < IP_MUX_SESSION_START ||
if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist)))
return;
if (WARN_ON(rcu_access_pointer(ipc_wwan->sub_netlist[if_id]) != priv))
return;
RCU_INIT_POINTER(ipc_wwan->sub_netlist[if_id], NULL);
/* unregistering includes synchronize_net() */
unregister_netdevice_queue(dev, head);
}
static const struct wwan_ops iosm_wwan_ops = {
.priv_size = sizeof(struct iosm_netdev_priv),
.setup = ipc_wwan_setup,
.newlink = ipc_wwan_newlink,
.dellink = ipc_wwan_dellink,
};
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;
struct iosm_netdev_priv *priv;
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 < IP_MUX_SESSION_START ||
if_id > IP_MUX_SESSION_END) {
ret = -EINVAL;
goto free;
}
rcu_read_lock();
priv = rcu_dereference(ipc_wwan->sub_netlist[if_id]);
if (!priv) {
ret = -EINVAL;
goto unlock;
}
skb->dev = priv->netdev;
stats = &priv->netdev->stats;
stats->rx_packets++;
stats->rx_bytes += skb->len;
ret = netif_rx(skb);
skb = NULL;
unlock:
rcu_read_unlock();
free:
dev_kfree_skb(skb);
return ret;
}
void ipc_wwan_tx_flowctrl(struct iosm_wwan *ipc_wwan, int if_id, bool on)
{
struct net_device *netdev;
struct iosm_netdev_priv *priv;
bool is_tx_blk;
rcu_read_lock();
priv = rcu_dereference(ipc_wwan->sub_netlist[if_id]);
if (!priv) {
rcu_read_unlock();
return;
}
netdev = priv->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();
}
struct iosm_wwan *ipc_wwan_init(struct iosm_imem *ipc_imem, struct device *dev)
{
struct iosm_wwan *ipc_wwan;
ipc_wwan = kzalloc(sizeof(*ipc_wwan), GFP_KERNEL);
if (!ipc_wwan)
return NULL;
ipc_wwan->dev = dev;
ipc_wwan->ipc_imem = ipc_imem;
/* WWAN core will create a netdev for the default IP MUX channel */
if (wwan_register_ops(ipc_wwan->dev, &iosm_wwan_ops, ipc_wwan,
IP_MUX_SESSION_DEFAULT)) {
kfree(ipc_wwan);
return NULL;
}
return ipc_wwan;
}
void ipc_wwan_deinit(struct iosm_wwan *ipc_wwan)
{
/* This call will remove all child netdev(s) */
wwan_unregister_ops(ipc_wwan->dev);
kfree(ipc_wwan);
}
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