/*
* Simulated Ethernet Driver
*
* Copyright (C) 1999-2001, 2003 Hewlett-Packard Co
* Stephane Eranian <eranian@hpl.hp.com>
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/in.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/inetdevice.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/notifier.h>
#include <linux/bitops.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/hpsim.h>
#include "hpsim_ssc.h"
#define SIMETH_RECV_MAX 10
/*
* Maximum possible received frame for Ethernet.
* We preallocate an sk_buff of that size to avoid costly
* memcpy for temporary buffer into sk_buff. We do basically
* what's done in other drivers, like eepro with a ring.
* The difference is, of course, that we don't have real DMA !!!
*/
#define SIMETH_FRAME_SIZE ETH_FRAME_LEN
#define NETWORK_INTR 8
struct simeth_local {
struct net_device_stats stats;
int simfd; /* descriptor in the simulator */
};
static int simeth_probe1(void);
static int simeth_open(struct net_device *dev);
static int simeth_close(struct net_device *dev);
static int simeth_tx(struct sk_buff *skb, struct net_device *dev);
static int simeth_rx(struct net_device *dev);
static struct net_device_stats *simeth_get_stats(struct net_device *dev);
static irqreturn_t simeth_interrupt(int irq, void *dev_id);
static void set_multicast_list(struct net_device *dev);
static int simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr);
static char *simeth_version="0.3";
/*
* This variable is used to establish a mapping between the Linux/ia64 kernel
* and the host linux kernel.
*
* As of today, we support only one card, even though most of the code
* is ready for many more. The mapping is then:
* linux/ia64 -> linux/x86
* eth0 -> eth1
*
* In the future, we some string operations, we could easily support up
* to 10 cards (0-9).
*
* The default mapping can be changed on the kernel command line by
* specifying simeth=ethX (or whatever string you want).
*/
static char *simeth_device="eth0"; /* default host interface to use */
static volatile unsigned int card_count; /* how many cards "found" so far */
static int simeth_debug; /* set to 1 to get debug information */
/*
* Used to catch IFF_UP & IFF_DOWN events
*/
static struct notifier_block simeth_dev_notifier = {
simeth_device_event,
NULL
};
/*
* Function used when using a kernel command line option.
*
* Format: simeth=interface_name (like eth0)
*/
static int __init
simeth_setup(char *str)
{
simeth_device = str;
return 1;
}
__setup("simeth=", simeth_setup);
/*
* Function used to probe for simeth devices when not installed
* as a loadable module
*/
int __init
simeth_probe (void)
{
int r;
printk(KERN_INFO "simeth: v%s\n", simeth_version);
r = simeth_probe1();
if (r == 0) register_netdevice_notifier(&simeth_dev_notifier);
return r;
}
static inline int
netdev_probe(char *name, unsigned char *ether)
{
return ia64_ssc(__pa(name), __pa(ether), 0,0, SSC_NETDEV_PROBE);
}
static inline int
netdev_connect(int irq)
{
/* XXX Fix me
* this does not support multiple cards
* also no return value
*/
ia64_ssc_connect_irq(NETWORK_INTR, irq);
return 0;
}
static inline int
netdev_attach(int fd, int irq, unsigned int ipaddr)
{
/* this puts the host interface in the right mode (start interrupting) */
return ia64_ssc(fd, ipaddr, 0,0, SSC_NETDEV_ATTACH);
}
static inline int
netdev_detach(int fd)
{
/*
* inactivate the host interface (don't interrupt anymore) */
return ia64_ssc(fd, 0,0,0, SSC_NETDEV_DETACH);
}
static inline int
netdev_send(int fd, unsigned char *buf, unsigned int len)
{
return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_SEND);
}
static inline int
netdev_read(int fd, unsigned char *buf, unsigned int len)
{
return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_RECV);
}
/*
* Function shared with module code, so cannot be in init section
*
* So far this function "detects" only one card (test_&_set) but could
* be extended easily.
*
* Return:
* - -ENODEV is no device found
* - -ENOMEM is no more memory
* - 0 otherwise
*/
static int
simeth_probe1(void)
{
unsigned char mac_addr[ETH_ALEN];
struct simeth_local *local;
struct net_device *dev;
int fd, i, err, rc;
/*
* XXX Fix me
* let's support just one card for now
*/
if (test_and_set_bit(0, &card_count))
return -ENODEV;
/*
* check with the simulator for the device
*/
fd = netdev_probe(simeth_device, mac_addr);
if (fd == -1)
return -ENODEV;
dev = alloc_etherdev(sizeof(struct simeth_local));
if (!dev)
return -ENOMEM;
memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr));
local = dev->priv;
local->simfd = fd; /* keep track of underlying file descriptor */
dev->open = simeth_open;
dev->stop = simeth_close;
dev->hard_start_xmit = simeth_tx;
dev->get_stats = simeth_get_stats;
dev->set_multicast_list = set_multicast_list; /* no yet used */
err = register_netdev(dev);
if (err) {
free_netdev(dev);
return err;
}
if ((rc = assign_irq_vector(AUTO_ASSIGN)) < 0)
panic("%s: out of interrupt vectors!\n", __FUNCTION__);
dev->irq = rc;
/*
* attach the interrupt in the simulator, this does enable interrupts
* until a netdev_attach() is called
*/
netdev_connect(dev->irq);
printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr",
dev->name, simeth_device, local->simfd);
for(i = 0; i < ETH_ALEN; i++) {
printk(" %2.2x", dev->dev_addr[i]);
}
printk(", IRQ %d\n", dev->irq);
return 0;
}
/*
* actually binds the device to an interrupt vector
*/
static int
simeth_open(struct net_device *dev)
{
if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) {
printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq);
return -EAGAIN;
}
netif_start_queue(dev);
return 0;
}
/* copied from lapbether.c */
static __inline__ int dev_is_ethdev(struct net_device *dev)
{
return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5));
}
/*
* Handler for IFF_UP or IFF_DOWN
*
* The reason for that is that we don't want to be interrupted when the
* interface is down. There is no way to unconnect in the simualtor. Instead
* we use this function to shutdown packet processing in the frame filter
* in the simulator. Thus no interrupts are generated
*
*
* That's also the place where we pass the IP address of this device to the
* simulator so that that we can start filtering packets for it
*
* There may be a better way of doing this, but I don't know which yet.
*/
static int
simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr)
{
struct net_device *dev = ptr;
struct simeth_local *local;
struct in_device *in_dev;
struct in_ifaddr **ifap = NULL;
struct in_ifaddr *ifa = NULL;
int r;
if ( ! dev ) {
printk(KERN_WARNING "simeth_device_event dev=0\n");
return NOTIFY_DONE;
}
if (dev->nd_net != &init_net)
return NOTIFY_DONE;
if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE;
/*
* Check whether or not it's for an ethernet device
*
* XXX Fixme: This works only as long as we support one
* type of ethernet device.
*/
if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE;
if ((in_dev=dev->ip_ptr) != NULL) {
for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next)
if (strcmp(dev->name, ifa->ifa_label) == 0) break;
}
if ( ifa == NULL ) {
printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name);
return NOTIFY_DONE;
}
printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n",
dev->name, ntohl(ifa->ifa_local));
/*
* XXX Fix me
* if the device was up, and we're simply reconfiguring it, not sure
* we get DOWN then UP.
*/
local = dev->priv;
/* now do it for real */
r = event == NETDEV_UP ?
netdev_attach(local->simfd, dev->irq, ntohl(ifa->ifa_local)):
netdev_detach(local->simfd);
printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n",
event == NETDEV_UP ? "attach":"detach", r);
return NOTIFY_DONE;
}
static int
simeth_close(struct net_device *dev)
{
netif_stop_queue(dev);
free_irq(dev->irq, dev);
return 0;
}
/*
* Only used for debug
*/
static void
frame_print(unsigned char *from, unsigned char *frame, int len)
{
int i;
printk("%s: (%d) %02x", from, len, frame[0] & 0xff);
for(i=1; i < 6; i++ ) {
printk(":%02x", frame[i] &0xff);
}
printk(" %2x", frame[6] &0xff);
for(i=7; i < 12; i++ ) {
printk(":%02x", frame[i] &0xff);
}
printk(" [%02x%02x]\n", frame[12], frame[13]);
for(i=14; i < len; i++ ) {
printk("%02x ", frame[i] &0xff);
if ( (i%10)==0) printk("\n");
}
printk("\n");
}
/*
* Function used to transmit of frame, very last one on the path before
* going to the simulator.
*/
static int
simeth_tx(struct sk_buff *skb, struct net_device *dev)
{
struct simeth_local *local = dev->priv;
#if 0
/* ensure we have at least ETH_ZLEN bytes (min frame size) */
unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
/* Where do the extra padding bytes comes from inthe skbuff ? */
#else
/* the real driver in the host system is going to take care of that
* or maybe it's the NIC itself.
*/
unsigned int length = skb->len;
#endif
local->stats.tx_bytes += skb->len;
local->stats.tx_packets++;
if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length);
netdev_send(local->simfd, skb->data, length);
/*
* we are synchronous on write, so we don't simulate a
* trasnmit complete interrupt, thus we don't need to arm a tx
*/
dev_kfree_skb(skb);
return 0;
}
static inline struct sk_buff *
make_new_skb(struct net_device *dev)
{
struct sk_buff *nskb;
/*
* The +2 is used to make sure that the IP header is nicely
* aligned (on 4byte boundary I assume 14+2=16)
*/
nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2);
if ( nskb == NULL ) {
printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
return NULL;
}
skb_reserve(nskb, 2); /* Align IP on 16 byte boundaries */
skb_put(nskb,SIMETH_FRAME_SIZE);
return nskb;
}
/*
* called from interrupt handler to process a received frame
*/
static int
simeth_rx(struct net_device *dev)
{
struct simeth_local *local;
struct sk_buff *skb;
int len;
int rcv_count = SIMETH_RECV_MAX;
local = dev->priv;
/*
* the loop concept has been borrowed from other drivers
* looks to me like it's a throttling thing to avoid pushing to many
* packets at one time into the stack. Making sure we can process them
* upstream and make forward progress overall
*/
do {
if ( (skb=make_new_skb(dev)) == NULL ) {
printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name);
local->stats.rx_dropped++;
return 0;
}
/*
* Read only one frame at a time
*/
len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE);
if ( len == 0 ) {
if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n",
dev->name, SIMETH_RECV_MAX-rcv_count);
break;
}
#if 0
/*
* XXX Fix me
* Should really do a csum+copy here
*/
skb_copy_to_linear_data(skb, frame, len);
#endif
skb->protocol = eth_type_trans(skb, dev);
if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len);
/*
* push the packet up & trigger software interrupt
*/
netif_rx(skb);
local->stats.rx_packets++;
local->stats.rx_bytes += len;
} while ( --rcv_count );
return len; /* 0 = nothing left to read, otherwise, we can try again */
}
/*
* Interrupt handler (Yes, we can do it too !!!)
*/
static irqreturn_t
simeth_interrupt(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
if ( dev == NULL ) {
printk(KERN_WARNING "simeth: irq %d for unknown device\n", irq);
return IRQ_NONE;
}
/*
* very simple loop because we get interrupts only when receiving
*/
while (simeth_rx(dev));
return IRQ_HANDLED;
}
static struct net_device_stats *
simeth_get_stats(struct net_device *dev)
{
struct simeth_local *local = dev->priv;
return &local->stats;
}
/* fake multicast ability */
static void
set_multicast_list(struct net_device *dev)
{
printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name);
}
__initcall(simeth_probe);
