// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* arch/xtensa/platforms/iss/network.c
*
* Platform specific initialization.
*
* Authors: Chris Zankel <[email protected]>
* Based on work form the UML team.
*
* Copyright 2005 Tensilica Inc.
*/
#define pr_fmt(fmt) "%s: " fmt, __func__
#include <linux/list.h>
#include <linux/irq.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/if_ether.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/if_tun.h>
#include <linux/etherdevice.h>
#include <linux/interrupt.h>
#include <linux/ioctl.h>
#include <linux/memblock.h>
#include <linux/ethtool.h>
#include <linux/rtnetlink.h>
#include <linux/platform_device.h>
#include <platform/simcall.h>
#define DRIVER_NAME "iss-netdev"
#define ETH_MAX_PACKET 1500
#define ETH_HEADER_OTHER 14
#define ISS_NET_TIMER_VALUE (HZ / 10)
/* ------------------------------------------------------------------------- */
/* We currently only support the TUNTAP transport protocol. */
#define TRANSPORT_TUNTAP_NAME "tuntap"
#define TRANSPORT_TUNTAP_MTU ETH_MAX_PACKET
struct tuntap_info {
char dev_name[IFNAMSIZ];
int fd;
};
/* ------------------------------------------------------------------------- */
struct iss_net_private;
struct iss_net_ops {
int (*open)(struct iss_net_private *lp);
void (*close)(struct iss_net_private *lp);
int (*read)(struct iss_net_private *lp, struct sk_buff **skb);
int (*write)(struct iss_net_private *lp, struct sk_buff **skb);
unsigned short (*protocol)(struct sk_buff *skb);
int (*poll)(struct iss_net_private *lp);
};
/* This structure contains out private information for the driver. */
struct iss_net_private {
spinlock_t lock;
struct net_device *dev;
struct platform_device pdev;
struct timer_list tl;
struct rtnl_link_stats64 stats;
struct timer_list timer;
unsigned int timer_val;
int index;
int mtu;
struct {
union {
struct tuntap_info tuntap;
} info;
const struct iss_net_ops *net_ops;
} tp;
};
/* ================================ HELPERS ================================ */
static char *split_if_spec(char *str, ...)
{
char **arg, *end;
va_list ap;
va_start(ap, str);
while ((arg = va_arg(ap, char**)) != NULL) {
if (*str == '\0') {
va_end(ap);
return NULL;
}
end = strchr(str, ',');
if (end != str)
*arg = str;
if (end == NULL) {
va_end(ap);
return NULL;
}
*end++ = '\0';
str = end;
}
va_end(ap);
return str;
}
/* Set Ethernet address of the specified device. */
static void setup_etheraddr(struct net_device *dev, char *str)
{
u8 addr[ETH_ALEN];
if (str == NULL)
goto random;
if (!mac_pton(str, addr)) {
pr_err("%s: failed to parse '%s' as an ethernet address\n",
dev->name, str);
goto random;
}
if (is_multicast_ether_addr(addr)) {
pr_err("%s: attempt to assign a multicast ethernet address\n",
dev->name);
goto random;
}
if (!is_valid_ether_addr(addr)) {
pr_err("%s: attempt to assign an invalid ethernet address\n",
dev->name);
goto random;
}
if (!is_local_ether_addr(addr))
pr_warn("%s: assigning a globally valid ethernet address\n",
dev->name);
eth_hw_addr_set(dev, addr);
return;
random:
pr_info("%s: choosing a random ethernet address\n",
dev->name);
eth_hw_addr_random(dev);
}
/* ======================= TUNTAP TRANSPORT INTERFACE ====================== */
static int tuntap_open(struct iss_net_private *lp)
{
struct ifreq ifr;
char *dev_name = lp->tp.info.tuntap.dev_name;
int err = -EINVAL;
int fd;
fd = simc_open("/dev/net/tun", 02, 0); /* O_RDWR */
if (fd < 0) {
pr_err("%s: failed to open /dev/net/tun, returned %d (errno = %d)\n",
lp->dev->name, fd, errno);
return fd;
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
strscpy(ifr.ifr_name, dev_name, sizeof(ifr.ifr_name));
err = simc_ioctl(fd, TUNSETIFF, &ifr);
if (err < 0) {
pr_err("%s: failed to set interface %s, returned %d (errno = %d)\n",
lp->dev->name, dev_name, err, errno);
simc_close(fd);
return err;
}
lp->tp.info.tuntap.fd = fd;
return err;
}
static void tuntap_close(struct iss_net_private *lp)
{
simc_close(lp->tp.info.tuntap.fd);
lp->tp.info.tuntap.fd = -1;
}
static int tuntap_read(struct iss_net_private *lp, struct sk_buff **skb)
{
return simc_read(lp->tp.info.tuntap.fd,
(*skb)->data, (*skb)->dev->mtu + ETH_HEADER_OTHER);
}
static int tuntap_write(struct iss_net_private *lp, struct sk_buff **skb)
{
return simc_write(lp->tp.info.tuntap.fd, (*skb)->data, (*skb)->len);
}
static unsigned short tuntap_protocol(struct sk_buff *skb)
{
return eth_type_trans(skb, skb->dev);
}
static int tuntap_poll(struct iss_net_private *lp)
{
return simc_poll(lp->tp.info.tuntap.fd);
}
static const struct iss_net_ops tuntap_ops = {
.open = tuntap_open,
.close = tuntap_close,
.read = tuntap_read,
.write = tuntap_write,
.protocol = tuntap_protocol,
.poll = tuntap_poll,
};
/*
* ethX=tuntap,[mac address],device name
*/
static int tuntap_probe(struct iss_net_private *lp, int index, char *init)
{
struct net_device *dev = lp->dev;
char *dev_name = NULL, *mac_str = NULL, *rem = NULL;
/* Transport should be 'tuntap': ethX=tuntap,mac,dev_name */
if (strncmp(init, TRANSPORT_TUNTAP_NAME,
sizeof(TRANSPORT_TUNTAP_NAME) - 1))
return 0;
init += sizeof(TRANSPORT_TUNTAP_NAME) - 1;
if (*init == ',') {
rem = split_if_spec(init + 1, &mac_str, &dev_name, NULL);
if (rem != NULL) {
pr_err("%s: extra garbage on specification : '%s'\n",
dev->name, rem);
return 0;
}
} else if (*init != '\0') {
pr_err("%s: invalid argument: %s. Skipping device!\n",
dev->name, init);
return 0;
}
if (!dev_name) {
pr_err("%s: missing tuntap device name\n", dev->name);
return 0;
}
strscpy(lp->tp.info.tuntap.dev_name, dev_name,
sizeof(lp->tp.info.tuntap.dev_name));
setup_etheraddr(dev, mac_str);
lp->mtu = TRANSPORT_TUNTAP_MTU;
lp->tp.info.tuntap.fd = -1;
lp->tp.net_ops = &tuntap_ops;
return 1;
}
/* ================================ ISS NET ================================ */
static int iss_net_rx(struct net_device *dev)
{
struct iss_net_private *lp = netdev_priv(dev);
int pkt_len;
struct sk_buff *skb;
/* Check if there is any new data. */
if (lp->tp.net_ops->poll(lp) == 0)
return 0;
/* Try to allocate memory, if it fails, try again next round. */
skb = dev_alloc_skb(dev->mtu + 2 + ETH_HEADER_OTHER);
if (skb == NULL) {
spin_lock_bh(&lp->lock);
lp->stats.rx_dropped++;
spin_unlock_bh(&lp->lock);
return 0;
}
skb_reserve(skb, 2);
/* Setup skb */
skb->dev = dev;
skb_reset_mac_header(skb);
pkt_len = lp->tp.net_ops->read(lp, &skb);
skb_put(skb, pkt_len);
if (pkt_len > 0) {
skb_trim(skb, pkt_len);
skb->protocol = lp->tp.net_ops->protocol(skb);
spin_lock_bh(&lp->lock);
lp->stats.rx_bytes += skb->len;
lp->stats.rx_packets++;
spin_unlock_bh(&lp->lock);
netif_rx(skb);
return pkt_len;
}
kfree_skb(skb);
return pkt_len;
}
static int iss_net_poll(struct iss_net_private *lp)
{
int err, ret = 0;
if (!netif_running(lp->dev))
return 0;
while ((err = iss_net_rx(lp->dev)) > 0)
ret++;
if (err < 0) {
pr_err("Device '%s' read returned %d, shutting it down\n",
lp->dev->name, err);
dev_close(lp->dev);
} else {
/* FIXME reactivate_fd(lp->fd, ISS_ETH_IRQ); */
}
return ret;
}
static void iss_net_timer(struct timer_list *t)
{
struct iss_net_private *lp = from_timer(lp, t, timer);
iss_net_poll(lp);
mod_timer(&lp->timer, jiffies + lp->timer_val);
}
static int iss_net_open(struct net_device *dev)
{
struct iss_net_private *lp = netdev_priv(dev);
int err;
err = lp->tp.net_ops->open(lp);
if (err < 0)
return err;
netif_start_queue(dev);
/* clear buffer - it can happen that the host side of the interface
* is full when we get here. In this case, new data is never queued,
* SIGIOs never arrive, and the net never works.
*/
while ((err = iss_net_rx(dev)) > 0)
;
timer_setup(&lp->timer, iss_net_timer, 0);
lp->timer_val = ISS_NET_TIMER_VALUE;
mod_timer(&lp->timer, jiffies + lp->timer_val);
return err;
}
static int iss_net_close(struct net_device *dev)
{
struct iss_net_private *lp = netdev_priv(dev);
netif_stop_queue(dev);
del_timer_sync(&lp->timer);
lp->tp.net_ops->close(lp);
return 0;
}
static int iss_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct iss_net_private *lp = netdev_priv(dev);
int len;
netif_stop_queue(dev);
len = lp->tp.net_ops->write(lp, &skb);
if (len == skb->len) {
spin_lock_bh(&lp->lock);
lp->stats.tx_packets++;
lp->stats.tx_bytes += skb->len;
spin_unlock_bh(&lp->lock);
netif_trans_update(dev);
netif_start_queue(dev);
/* this is normally done in the interrupt when tx finishes */
netif_wake_queue(dev);
} else if (len == 0) {
netif_start_queue(dev);
spin_lock_bh(&lp->lock);
lp->stats.tx_dropped++;
spin_unlock_bh(&lp->lock);
} else {
netif_start_queue(dev);
pr_err("%s: %s failed(%d)\n", dev->name, __func__, len);
}
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
static void iss_net_get_stats64(struct net_device *dev,
struct rtnl_link_stats64 *stats)
{
struct iss_net_private *lp = netdev_priv(dev);
spin_lock_bh(&lp->lock);
*stats = lp->stats;
spin_unlock_bh(&lp->lock);
}
static void iss_net_set_multicast_list(struct net_device *dev)
{
}
static void iss_net_tx_timeout(struct net_device *dev, unsigned int txqueue)
{
}
static int iss_net_change_mtu(struct net_device *dev, int new_mtu)
{
return -EINVAL;
}
static void iss_net_user_timer_expire(struct timer_list *unused)
{
}
static struct platform_driver iss_net_driver = {
.driver = {
.name = DRIVER_NAME,
},
};
static int driver_registered;
static const struct net_device_ops iss_netdev_ops = {
.ndo_open = iss_net_open,
.ndo_stop = iss_net_close,
.ndo_get_stats64 = iss_net_get_stats64,
.ndo_start_xmit = iss_net_start_xmit,
.ndo_validate_addr = eth_validate_addr,
.ndo_change_mtu = iss_net_change_mtu,
.ndo_set_mac_address = eth_mac_addr,
.ndo_tx_timeout = iss_net_tx_timeout,
.ndo_set_rx_mode = iss_net_set_multicast_list,
};
static void iss_net_pdev_release(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct iss_net_private *lp =
container_of(pdev, struct iss_net_private, pdev);
free_netdev(lp->dev);
}
static void iss_net_configure(int index, char *init)
{
struct net_device *dev;
struct iss_net_private *lp;
dev = alloc_etherdev(sizeof(*lp));
if (dev == NULL) {
pr_err("eth_configure: failed to allocate device\n");
return;
}
/* Initialize private element. */
lp = netdev_priv(dev);
*lp = (struct iss_net_private) {
.dev = dev,
.index = index,
};
spin_lock_init(&lp->lock);
/*
* If this name ends up conflicting with an existing registered
* netdevice, that is OK, register_netdev{,ice}() will notice this
* and fail.
*/
snprintf(dev->name, sizeof(dev->name), "eth%d", index);
/*
* Try all transport protocols.
* Note: more protocols can be added by adding '&& !X_init(lp, eth)'.
*/
if (!tuntap_probe(lp, index, init)) {
pr_err("%s: invalid arguments. Skipping device!\n",
dev->name);
goto err_free_netdev;
}
pr_info("Netdevice %d (%pM)\n", index, dev->dev_addr);
/* sysfs register */
if (!driver_registered) {
if (platform_driver_register(&iss_net_driver))
goto err_free_netdev;
driver_registered = 1;
}
lp->pdev.id = index;
lp->pdev.name = DRIVER_NAME;
lp->pdev.dev.release = iss_net_pdev_release;
if (platform_device_register(&lp->pdev))
goto err_free_netdev;
SET_NETDEV_DEV(dev, &lp->pdev.dev);
dev->netdev_ops = &iss_netdev_ops;
dev->mtu = lp->mtu;
dev->watchdog_timeo = (HZ >> 1);
dev->irq = -1;
rtnl_lock();
if (register_netdevice(dev)) {
rtnl_unlock();
pr_err("%s: error registering net device!\n", dev->name);
platform_device_unregister(&lp->pdev);
/* dev is freed by the iss_net_pdev_release callback */
return;
}
rtnl_unlock();
timer_setup(&lp->tl, iss_net_user_timer_expire, 0);
return;
err_free_netdev:
free_netdev(dev);
}
/* ------------------------------------------------------------------------- */
/* Filled in during early boot */
struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
struct iss_net_init {
struct list_head list;
char *init; /* init string */
int index;
};
/*
* Parse the command line and look for 'ethX=...' fields, and register all
* those fields. They will be later initialized in iss_net_init.
*/
static int __init iss_net_setup(char *str)
{
struct iss_net_init *device = NULL;
struct iss_net_init *new;
struct list_head *ele;
char *end;
int rc;
unsigned n;
end = strchr(str, '=');
if (!end) {
pr_err("Expected '=' after device number\n");
return 1;
}
*end = 0;
rc = kstrtouint(str, 0, &n);
*end = '=';
if (rc < 0) {
pr_err("Failed to parse '%s'\n", str);
return 1;
}
str = end;
list_for_each(ele, ð_cmd_line) {
device = list_entry(ele, struct iss_net_init, list);
if (device->index == n)
break;
}
if (device && device->index == n) {
pr_err("Device %u already configured\n", n);
return 1;
}
new = memblock_alloc(sizeof(*new), SMP_CACHE_BYTES);
if (new == NULL) {
pr_err("Alloc_bootmem failed\n");
return 1;
}
INIT_LIST_HEAD(&new->list);
new->index = n;
new->init = str + 1;
list_add_tail(&new->list, ð_cmd_line);
return 1;
}
__setup("eth", iss_net_setup);
/*
* Initialize all ISS Ethernet devices previously registered in iss_net_setup.
*/
static int iss_net_init(void)
{
struct list_head *ele, *next;
/* Walk through all Ethernet devices specified in the command line. */
list_for_each_safe(ele, next, ð_cmd_line) {
struct iss_net_init *eth;
eth = list_entry(ele, struct iss_net_init, list);
iss_net_configure(eth->index, eth->init);
}
return 1;
}
device_initcall(iss_net_init);
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