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linux/drivers/net/arcnet/arcnet.c

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/*
* Linux ARCnet driver - device-independent routines
*
* Written 1997 by David Woodhouse.
* Written 1994-1999 by Avery Pennarun.
* Written 1999-2000 by Martin Mares <mj@ucw.cz>.
* Derived from skeleton.c by Donald Becker.
*
* Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
* for sponsoring the further development of this driver.
*
* **********************
*
* The original copyright was as follows:
*
* skeleton.c Written 1993 by Donald Becker.
* Copyright 1993 United States Government as represented by the
* Director, National Security Agency. This software may only be used
* and distributed according to the terms of the GNU General Public License as
* modified by SRC, incorporated herein by reference.
*
* **********************
*
* The change log is now in a file called ChangeLog in this directory.
*
* Sources:
* - Crynwr arcnet.com/arcether.com packet drivers.
* - arcnet.c v0.00 dated 1/1/94 and apparently by
* Donald Becker - it didn't work :)
* - skeleton.c v0.05 dated 11/16/93 by Donald Becker
* (from Linux Kernel 1.1.45)
* - RFC's 1201 and 1051 - re: TCP/IP over ARCnet
* - The official ARCnet COM9026 data sheets (!) thanks to
* Ken Cornetet <kcornete@nyx10.cs.du.edu>
* - The official ARCnet COM20020 data sheets.
* - Information on some more obscure ARCnet controller chips, thanks
* to the nice people at SMSC.
* - net/inet/eth.c (from kernel 1.1.50) for header-building info.
* - Alternate Linux ARCnet source by V.Shergin <vsher@sao.stavropol.su>
* - Textual information and more alternate source from Joachim Koenig
* <jojo@repas.de>
*/
#define VERSION "arcnet: v3.94 BETA 2007/02/08 - by Avery Pennarun et al.\n"
#include <linux/module.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <net/arp.h>
#include <linux/init.h>
#include <linux/arcdevice.h>
#include <linux/jiffies.h>
/* "do nothing" functions for protocol drivers */
static void null_rx(struct net_device *dev, int bufnum,
struct archdr *pkthdr, int length);
static int null_build_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, uint8_t daddr);
static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
int length, int bufnum);
static void arcnet_rx(struct net_device *dev, int bufnum);
/*
* one ArcProto per possible proto ID. None of the elements of
* arc_proto_map are allowed to be NULL; they will get set to
* arc_proto_default instead. It also must not be NULL; if you would like
* to set it to NULL, set it to &arc_proto_null instead.
*/
struct ArcProto *arc_proto_map[256], *arc_proto_default,
*arc_bcast_proto, *arc_raw_proto;
static struct ArcProto arc_proto_null =
{
.suffix = '?',
.mtu = XMTU,
.is_ip = 0,
.rx = null_rx,
.build_header = null_build_header,
.prepare_tx = null_prepare_tx,
.continue_tx = NULL,
.ack_tx = NULL
};
/* Exported function prototypes */
int arcnet_debug = ARCNET_DEBUG;
EXPORT_SYMBOL(arc_proto_map);
EXPORT_SYMBOL(arc_proto_default);
EXPORT_SYMBOL(arc_bcast_proto);
EXPORT_SYMBOL(arc_raw_proto);
EXPORT_SYMBOL(arcnet_unregister_proto);
EXPORT_SYMBOL(arcnet_debug);
EXPORT_SYMBOL(alloc_arcdev);
EXPORT_SYMBOL(arcnet_interrupt);
/* Internal function prototypes */
static int arcnet_open(struct net_device *dev);
static int arcnet_close(struct net_device *dev);
static int arcnet_send_packet(struct sk_buff *skb, struct net_device *dev);
static void arcnet_timeout(struct net_device *dev);
static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, const void *daddr,
const void *saddr, unsigned len);
static int arcnet_rebuild_header(struct sk_buff *skb);
static struct net_device_stats *arcnet_get_stats(struct net_device *dev);
static int go_tx(struct net_device *dev);
static int debug = ARCNET_DEBUG;
module_param(debug, int, 0);
MODULE_LICENSE("GPL");
static int __init arcnet_init(void)
{
int count;
arcnet_debug = debug;
printk("arcnet loaded.\n");
#ifdef ALPHA_WARNING
BUGLVL(D_EXTRA) {
printk("arcnet: ***\n"
"arcnet: * Read arcnet.txt for important release notes!\n"
"arcnet: *\n"
"arcnet: * This is an ALPHA version! (Last stable release: v3.02) E-mail\n"
"arcnet: * me if you have any questions, comments, or bug reports.\n"
"arcnet: ***\n");
}
#endif
/* initialize the protocol map */
arc_raw_proto = arc_proto_default = arc_bcast_proto = &arc_proto_null;
for (count = 0; count < 256; count++)
arc_proto_map[count] = arc_proto_default;
BUGLVL(D_DURING)
printk("arcnet: struct sizes: %Zd %Zd %Zd %Zd %Zd\n",
sizeof(struct arc_hardware), sizeof(struct arc_rfc1201),
sizeof(struct arc_rfc1051), sizeof(struct arc_eth_encap),
sizeof(struct archdr));
return 0;
}
static void __exit arcnet_exit(void)
{
}
module_init(arcnet_init);
module_exit(arcnet_exit);
/*
* Dump the contents of an sk_buff
*/
#if ARCNET_DEBUG_MAX & D_SKB
void arcnet_dump_skb(struct net_device *dev,
struct sk_buff *skb, char *desc)
{
int i;
printk(KERN_DEBUG "%6s: skb dump (%s) follows:", dev->name, desc);
for (i = 0; i < skb->len; i++) {
if (i % 16 == 0)
printk("\n" KERN_DEBUG "[%04X] ", i);
printk("%02X ", ((u_char *) skb->data)[i]);
}
printk("\n");
}
EXPORT_SYMBOL(arcnet_dump_skb);
#endif
/*
* Dump the contents of an ARCnet buffer
*/
#if (ARCNET_DEBUG_MAX & (D_RX | D_TX))
static void arcnet_dump_packet(struct net_device *dev, int bufnum,
char *desc, int take_arcnet_lock)
{
struct arcnet_local *lp = dev->priv;
int i, length;
unsigned long flags = 0;
static uint8_t buf[512];
/* hw.copy_from_card expects IRQ context so take the IRQ lock
to keep it single threaded */
if(take_arcnet_lock)
spin_lock_irqsave(&lp->lock, flags);
lp->hw.copy_from_card(dev, bufnum, 0, buf, 512);
if(take_arcnet_lock)
spin_unlock_irqrestore(&lp->lock, flags);
/* if the offset[0] byte is nonzero, this is a 256-byte packet */
length = (buf[2] ? 256 : 512);
printk(KERN_DEBUG "%6s: packet dump (%s) follows:", dev->name, desc);
for (i = 0; i < length; i++) {
if (i % 16 == 0)
printk("\n" KERN_DEBUG "[%04X] ", i);
printk("%02X ", buf[i]);
}
printk("\n");
}
#else
#define arcnet_dump_packet(dev, bufnum, desc,take_arcnet_lock) do { } while (0)
#endif
/*
* Unregister a protocol driver from the arc_proto_map. Protocol drivers
* are responsible for registering themselves, but the unregister routine
* is pretty generic so we'll do it here.
*/
void arcnet_unregister_proto(struct ArcProto *proto)
{
int count;
if (arc_proto_default == proto)
arc_proto_default = &arc_proto_null;
if (arc_bcast_proto == proto)
arc_bcast_proto = arc_proto_default;
if (arc_raw_proto == proto)
arc_raw_proto = arc_proto_default;
for (count = 0; count < 256; count++) {
if (arc_proto_map[count] == proto)
arc_proto_map[count] = arc_proto_default;
}
}
/*
* Add a buffer to the queue. Only the interrupt handler is allowed to do
* this, unless interrupts are disabled.
*
* Note: we don't check for a full queue, since there aren't enough buffers
* to more than fill it.
*/
static void release_arcbuf(struct net_device *dev, int bufnum)
{
struct arcnet_local *lp = dev->priv;
int i;
lp->buf_queue[lp->first_free_buf++] = bufnum;
lp->first_free_buf %= 5;
BUGLVL(D_DURING) {
BUGMSG(D_DURING, "release_arcbuf: freed #%d; buffer queue is now: ",
bufnum);
for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5)
BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]);
BUGMSG2(D_DURING, "\n");
}
}
/*
* Get a buffer from the queue. If this returns -1, there are no buffers
* available.
*/
static int get_arcbuf(struct net_device *dev)
{
struct arcnet_local *lp = dev->priv;
int buf = -1, i;
if (!atomic_dec_and_test(&lp->buf_lock)) {
/* already in this function */
BUGMSG(D_NORMAL, "get_arcbuf: overlap (%d)!\n",
lp->buf_lock.counter);
}
else { /* we can continue */
if (lp->next_buf >= 5)
lp->next_buf -= 5;
if (lp->next_buf == lp->first_free_buf)
BUGMSG(D_NORMAL, "get_arcbuf: BUG: no buffers are available??\n");
else {
buf = lp->buf_queue[lp->next_buf++];
lp->next_buf %= 5;
}
}
BUGLVL(D_DURING) {
BUGMSG(D_DURING, "get_arcbuf: got #%d; buffer queue is now: ", buf);
for (i = lp->next_buf; i != lp->first_free_buf; i = (i+1) % 5)
BUGMSG2(D_DURING, "#%d ", lp->buf_queue[i]);
BUGMSG2(D_DURING, "\n");
}
atomic_inc(&lp->buf_lock);
return buf;
}
static int choose_mtu(void)
{
int count, mtu = 65535;
/* choose the smallest MTU of all available encaps */
for (count = 0; count < 256; count++) {
if (arc_proto_map[count] != &arc_proto_null
&& arc_proto_map[count]->mtu < mtu) {
mtu = arc_proto_map[count]->mtu;
}
}
return mtu == 65535 ? XMTU : mtu;
}
static const struct header_ops arcnet_header_ops = {
.create = arcnet_header,
.rebuild = arcnet_rebuild_header,
};
/* Setup a struct device for ARCnet. */
static void arcdev_setup(struct net_device *dev)
{
dev->type = ARPHRD_ARCNET;
dev->header_ops = &arcnet_header_ops;
dev->hard_header_len = sizeof(struct archdr);
dev->mtu = choose_mtu();
dev->addr_len = ARCNET_ALEN;
dev->tx_queue_len = 100;
dev->broadcast[0] = 0x00; /* for us, broadcasts are address 0 */
dev->watchdog_timeo = TX_TIMEOUT;
/* New-style flags. */
dev->flags = IFF_BROADCAST;
/*
* Put in this stuff here, so we don't have to export the symbols to
* the chipset drivers.
*/
dev->open = arcnet_open;
dev->stop = arcnet_close;
dev->hard_start_xmit = arcnet_send_packet;
dev->tx_timeout = arcnet_timeout;
dev->get_stats = arcnet_get_stats;
}
struct net_device *alloc_arcdev(char *name)
{
struct net_device *dev;
dev = alloc_netdev(sizeof(struct arcnet_local),
name && *name ? name : "arc%d", arcdev_setup);
if(dev) {
struct arcnet_local *lp = (struct arcnet_local *) dev->priv;
spin_lock_init(&lp->lock);
}
return dev;
}
/*
* Open/initialize the board. This is called sometime after booting when
* the 'ifconfig' program is run.
*
* This routine should set everything up anew at each open, even registers
* that "should" only need to be set once at boot, so that there is
* non-reboot way to recover if something goes wrong.
*/
static int arcnet_open(struct net_device *dev)
{
struct arcnet_local *lp = dev->priv;
int count, newmtu, error;
BUGMSG(D_INIT,"opened.");
if (!try_module_get(lp->hw.owner))
return -ENODEV;
BUGLVL(D_PROTO) {
int count;
BUGMSG(D_PROTO, "protocol map (default is '%c'): ",
arc_proto_default->suffix);
for (count = 0; count < 256; count++)
BUGMSG2(D_PROTO, "%c", arc_proto_map[count]->suffix);
BUGMSG2(D_PROTO, "\n");
}
BUGMSG(D_INIT, "arcnet_open: resetting card.\n");
/* try to put the card in a defined state - if it fails the first
* time, actually reset it.
*/
error = -ENODEV;
if (ARCRESET(0) && ARCRESET(1))
goto out_module_put;
newmtu = choose_mtu();
if (newmtu < dev->mtu)
dev->mtu = newmtu;
BUGMSG(D_INIT, "arcnet_open: mtu: %d.\n", dev->mtu);
/* autodetect the encapsulation for each host. */
memset(lp->default_proto, 0, sizeof(lp->default_proto));
/* the broadcast address is special - use the 'bcast' protocol */
for (count = 0; count < 256; count++) {
if (arc_proto_map[count] == arc_bcast_proto) {
lp->default_proto[0] = count;
break;
}
}
/* initialize buffers */
atomic_set(&lp->buf_lock, 1);
lp->next_buf = lp->first_free_buf = 0;
release_arcbuf(dev, 0);
release_arcbuf(dev, 1);
release_arcbuf(dev, 2);
release_arcbuf(dev, 3);
lp->cur_tx = lp->next_tx = -1;
lp->cur_rx = -1;
lp->rfc1201.sequence = 1;
/* bring up the hardware driver */
if (lp->hw.open)
lp->hw.open(dev);
if (dev->dev_addr[0] == 0)
BUGMSG(D_NORMAL, "WARNING! Station address 00 is reserved "
"for broadcasts!\n");
else if (dev->dev_addr[0] == 255)
BUGMSG(D_NORMAL, "WARNING! Station address FF may confuse "
"DOS networking programs!\n");
BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
if (ASTATUS() & RESETflag) {
BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
ACOMMAND(CFLAGScmd | RESETclear);
}
BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
/* make sure we're ready to receive IRQ's. */
AINTMASK(0);
udelay(1); /* give it time to set the mask before
* we reset it again. (may not even be
* necessary)
*/
BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
lp->intmask = NORXflag | RECONflag;
AINTMASK(lp->intmask);
BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
netif_start_queue(dev);
return 0;
out_module_put:
module_put(lp->hw.owner);
return error;
}
/* The inverse routine to arcnet_open - shuts down the card. */
static int arcnet_close(struct net_device *dev)
{
struct arcnet_local *lp = dev->priv;
netif_stop_queue(dev);
/* flush TX and disable RX */
AINTMASK(0);
ACOMMAND(NOTXcmd); /* stop transmit */
ACOMMAND(NORXcmd); /* disable receive */
mdelay(1);
/* shut down the card */
lp->hw.close(dev);
module_put(lp->hw.owner);
return 0;
}
static int arcnet_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, const void *daddr,
const void *saddr, unsigned len)
{
const struct arcnet_local *lp = netdev_priv(dev);
uint8_t _daddr, proto_num;
struct ArcProto *proto;
BUGMSG(D_DURING,
"create header from %d to %d; protocol %d (%Xh); size %u.\n",
saddr ? *(uint8_t *) saddr : -1,
daddr ? *(uint8_t *) daddr : -1,
type, type, len);
if (skb->len!=0 && len != skb->len)
BUGMSG(D_NORMAL, "arcnet_header: Yikes! skb->len(%d) != len(%d)!\n",
skb->len, len);
/* Type is host order - ? */
if(type == ETH_P_ARCNET) {
proto = arc_raw_proto;
BUGMSG(D_DEBUG, "arc_raw_proto used. proto='%c'\n",proto->suffix);
_daddr = daddr ? *(uint8_t *) daddr : 0;
}
else if (!daddr) {
/*
* if the dest addr isn't provided, we can't choose an encapsulation!
* Store the packet type (eg. ETH_P_IP) for now, and we'll push on a
* real header when we do rebuild_header.
*/
*(uint16_t *) skb_push(skb, 2) = type;
/*
* XXX: Why not use skb->mac_len?
*/
if (skb->network_header - skb->mac_header != 2)
BUGMSG(D_NORMAL, "arcnet_header: Yikes! diff (%d) is not 2!\n",
(int)(skb->network_header - skb->mac_header));
return -2; /* return error -- can't transmit yet! */
}
else {
/* otherwise, we can just add the header as usual. */
_daddr = *(uint8_t *) daddr;
proto_num = lp->default_proto[_daddr];
proto = arc_proto_map[proto_num];
BUGMSG(D_DURING, "building header for %02Xh using protocol '%c'\n",
proto_num, proto->suffix);
if (proto == &arc_proto_null && arc_bcast_proto != proto) {
BUGMSG(D_DURING, "actually, let's use '%c' instead.\n",
arc_bcast_proto->suffix);
proto = arc_bcast_proto;
}
}
return proto->build_header(skb, dev, type, _daddr);
}
/*
* Rebuild the ARCnet hard header. This is called after an ARP (or in the
* future other address resolution) has completed on this sk_buff. We now
* let ARP fill in the destination field.
*/
static int arcnet_rebuild_header(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
struct arcnet_local *lp = dev->priv;
int status = 0; /* default is failure */
unsigned short type;
uint8_t daddr=0;
struct ArcProto *proto;
/*
* XXX: Why not use skb->mac_len?
*/
if (skb->network_header - skb->mac_header != 2) {
BUGMSG(D_NORMAL,
"rebuild_header: shouldn't be here! (hdrsize=%d)\n",
(int)(skb->network_header - skb->mac_header));
return 0;
}
type = *(uint16_t *) skb_pull(skb, 2);
BUGMSG(D_DURING, "rebuild header for protocol %Xh\n", type);
if (type == ETH_P_IP) {
#ifdef CONFIG_INET
BUGMSG(D_DURING, "rebuild header for ethernet protocol %Xh\n", type);
status = arp_find(&daddr, skb) ? 1 : 0;
BUGMSG(D_DURING, " rebuilt: dest is %d; protocol %Xh\n",
daddr, type);
#endif
} else {
BUGMSG(D_NORMAL,
"I don't understand ethernet protocol %Xh addresses!\n", type);
lp->stats.tx_errors++;
lp->stats.tx_aborted_errors++;
}
/* if we couldn't resolve the address... give up. */
if (!status)
return 0;
/* add the _real_ header this time! */
proto = arc_proto_map[lp->default_proto[daddr]];
proto->build_header(skb, dev, type, daddr);
return 1; /* success */
}
/* Called by the kernel in order to transmit a packet. */
static int arcnet_send_packet(struct sk_buff *skb, struct net_device *dev)
{
struct arcnet_local *lp = dev->priv;
struct archdr *pkt;
struct arc_rfc1201 *soft;
struct ArcProto *proto;
int txbuf;
unsigned long flags;
int freeskb, retval;
BUGMSG(D_DURING,
"transmit requested (status=%Xh, txbufs=%d/%d, len=%d, protocol %x)\n",
ASTATUS(), lp->cur_tx, lp->next_tx, skb->len,skb->protocol);
pkt = (struct archdr *) skb->data;
soft = &pkt->soft.rfc1201;
proto = arc_proto_map[soft->proto];
BUGMSG(D_SKB_SIZE, "skb: transmitting %d bytes to %02X\n",
skb->len, pkt->hard.dest);
BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "tx");
/* fits in one packet? */
if (skb->len - ARC_HDR_SIZE > XMTU && !proto->continue_tx) {
BUGMSG(D_NORMAL, "fixme: packet too large: compensating badly!\n");
dev_kfree_skb(skb);
return NETDEV_TX_OK; /* don't try again */
}
/* We're busy transmitting a packet... */
netif_stop_queue(dev);
spin_lock_irqsave(&lp->lock, flags);
AINTMASK(0);
if(lp->next_tx == -1)
txbuf = get_arcbuf(dev);
else {
txbuf = -1;
}
if (txbuf != -1) {
if (proto->prepare_tx(dev, pkt, skb->len, txbuf) &&
!proto->ack_tx) {
/* done right away and we don't want to acknowledge
the package later - forget about it now */
lp->stats.tx_bytes += skb->len;
freeskb = 1;
} else {
/* do it the 'split' way */
lp->outgoing.proto = proto;
lp->outgoing.skb = skb;
lp->outgoing.pkt = pkt;
freeskb = 0;
if (proto->continue_tx &&
proto->continue_tx(dev, txbuf)) {
BUGMSG(D_NORMAL,
"bug! continue_tx finished the first time! "
"(proto='%c')\n", proto->suffix);
}
}
retval = NETDEV_TX_OK;
dev->trans_start = jiffies;
lp->next_tx = txbuf;
} else {
retval = NETDEV_TX_BUSY;
freeskb = 0;
}
BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__FUNCTION__,ASTATUS());
/* make sure we didn't ignore a TX IRQ while we were in here */
AINTMASK(0);
BUGMSG(D_DEBUG, "%s: %d: %s\n",__FILE__,__LINE__,__FUNCTION__);
lp->intmask |= TXFREEflag|EXCNAKflag;
AINTMASK(lp->intmask);
BUGMSG(D_DEBUG, "%s: %d: %s, status: %x\n",__FILE__,__LINE__,__FUNCTION__,ASTATUS());
spin_unlock_irqrestore(&lp->lock, flags);
if (freeskb) {
dev_kfree_skb(skb);
}
return retval; /* no need to try again */
}
/*
* Actually start transmitting a packet that was loaded into a buffer
* by prepare_tx. This should _only_ be called by the interrupt handler.
*/
static int go_tx(struct net_device *dev)
{
struct arcnet_local *lp = dev->priv;
BUGMSG(D_DURING, "go_tx: status=%Xh, intmask=%Xh, next_tx=%d, cur_tx=%d\n",
ASTATUS(), lp->intmask, lp->next_tx, lp->cur_tx);
if (lp->cur_tx != -1 || lp->next_tx == -1)
return 0;
BUGLVL(D_TX) arcnet_dump_packet(dev, lp->next_tx, "go_tx", 0);
lp->cur_tx = lp->next_tx;
lp->next_tx = -1;
/* start sending */
ACOMMAND(TXcmd | (lp->cur_tx << 3));
lp->stats.tx_packets++;
lp->lasttrans_dest = lp->lastload_dest;
lp->lastload_dest = 0;
lp->excnak_pending = 0;
lp->intmask |= TXFREEflag|EXCNAKflag;
return 1;
}
/* Called by the kernel when transmit times out */
static void arcnet_timeout(struct net_device *dev)
{
unsigned long flags;
struct arcnet_local *lp = dev->priv;
int status = ASTATUS();
char *msg;
spin_lock_irqsave(&lp->lock, flags);
if (status & TXFREEflag) { /* transmit _DID_ finish */
msg = " - missed IRQ?";
} else {
msg = "";
lp->stats.tx_aborted_errors++;
lp->timed_out = 1;
ACOMMAND(NOTXcmd | (lp->cur_tx << 3));
}
lp->stats.tx_errors++;
/* make sure we didn't miss a TX or a EXC NAK IRQ */
AINTMASK(0);
lp->intmask |= TXFREEflag|EXCNAKflag;
AINTMASK(lp->intmask);
spin_unlock_irqrestore(&lp->lock, flags);
if (time_after(jiffies, lp->last_timeout + 10*HZ)) {
BUGMSG(D_EXTRA, "tx timed out%s (status=%Xh, intmask=%Xh, dest=%02Xh)\n",
msg, status, lp->intmask, lp->lasttrans_dest);
lp->last_timeout = jiffies;
}
if (lp->cur_tx == -1)
netif_wake_queue(dev);
}
/*
* The typical workload of the driver: Handle the network interface
* interrupts. Establish which device needs attention, and call the correct
* chipset interrupt handler.
*/
irqreturn_t arcnet_interrupt(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
struct arcnet_local *lp;
int recbuf, status, diagstatus, didsomething, boguscount;
int retval = IRQ_NONE;
BUGMSG(D_DURING, "\n");
BUGMSG(D_DURING, "in arcnet_interrupt\n");
lp = dev->priv;
BUG_ON(!lp);
spin_lock(&lp->lock);
/*
* RESET flag was enabled - if device is not running, we must clear it right
* away (but nothing else).
*/
if (!netif_running(dev)) {
if (ASTATUS() & RESETflag)
ACOMMAND(CFLAGScmd | RESETclear);
AINTMASK(0);
spin_unlock(&lp->lock);
return IRQ_HANDLED;
}
BUGMSG(D_DURING, "in arcnet_inthandler (status=%Xh, intmask=%Xh)\n",
ASTATUS(), lp->intmask);
boguscount = 5;
do {
status = ASTATUS();
diagstatus = (status >> 8) & 0xFF;
BUGMSG(D_DEBUG, "%s: %d: %s: status=%x\n",
__FILE__,__LINE__,__FUNCTION__,status);
didsomething = 0;
/*
* RESET flag was enabled - card is resetting and if RX is
* disabled, it's NOT because we just got a packet.
*
* The card is in an undefined state. Clear it out and start over.
*/
if (status & RESETflag) {
BUGMSG(D_NORMAL, "spurious reset (status=%Xh)\n", status);
arcnet_close(dev);
arcnet_open(dev);
/* get out of the interrupt handler! */
break;
}
/*
* RX is inhibited - we must have received something. Prepare to
* receive into the next buffer.
*
* We don't actually copy the received packet from the card until
* after the transmit handler runs (and possibly launches the next
* tx); this should improve latency slightly if we get both types
* of interrupts at once.
*/
recbuf = -1;
if (status & lp->intmask & NORXflag) {
recbuf = lp->cur_rx;
BUGMSG(D_DURING, "Buffer #%d: receive irq (status=%Xh)\n",
recbuf, status);
lp->cur_rx = get_arcbuf(dev);
if (lp->cur_rx != -1) {
BUGMSG(D_DURING, "enabling receive to buffer #%d\n",
lp->cur_rx);
ACOMMAND(RXcmd | (lp->cur_rx << 3) | RXbcasts);
}
didsomething++;
}
if((diagstatus & EXCNAKflag)) {
BUGMSG(D_DURING, "EXCNAK IRQ (diagstat=%Xh)\n",
diagstatus);
ACOMMAND(NOTXcmd); /* disable transmit */
lp->excnak_pending = 1;
ACOMMAND(EXCNAKclear);
lp->intmask &= ~(EXCNAKflag);
didsomething++;
}
/* a transmit finished, and we're interested in it. */
if ((status & lp->intmask & TXFREEflag) || lp->timed_out) {
lp->intmask &= ~(TXFREEflag|EXCNAKflag);
BUGMSG(D_DURING, "TX IRQ (stat=%Xh)\n", status);
if (lp->cur_tx != -1 && !lp->timed_out) {
if(!(status & TXACKflag)) {
if (lp->lasttrans_dest != 0) {
BUGMSG(D_EXTRA,
"transmit was not acknowledged! "
"(status=%Xh, dest=%02Xh)\n",
status, lp->lasttrans_dest);
lp->stats.tx_errors++;
lp->stats.tx_carrier_errors++;
} else {
BUGMSG(D_DURING,
"broadcast was not acknowledged; that's normal "
"(status=%Xh, dest=%02Xh)\n",
status, lp->lasttrans_dest);
}
}
if (lp->outgoing.proto &&
lp->outgoing.proto->ack_tx) {
int ackstatus;
if(status & TXACKflag)
ackstatus=2;
else if(lp->excnak_pending)
ackstatus=1;
else
ackstatus=0;
lp->outgoing.proto
->ack_tx(dev, ackstatus);
}
}
if (lp->cur_tx != -1)
release_arcbuf(dev, lp->cur_tx);
lp->cur_tx = -1;
lp->timed_out = 0;
didsomething++;
/* send another packet if there is one */
go_tx(dev);
/* continue a split packet, if any */
if (lp->outgoing.proto && lp->outgoing.proto->continue_tx) {
int txbuf = get_arcbuf(dev);
if (txbuf != -1) {
if (lp->outgoing.proto->continue_tx(dev, txbuf)) {
/* that was the last segment */
lp->stats.tx_bytes += lp->outgoing.skb->len;
if(!lp->outgoing.proto->ack_tx)
{
dev_kfree_skb_irq(lp->outgoing.skb);
lp->outgoing.proto = NULL;
}
}
lp->next_tx = txbuf;
}
}
/* inform upper layers of idleness, if necessary */
if (lp->cur_tx == -1)
netif_wake_queue(dev);
}
/* now process the received packet, if any */
if (recbuf != -1) {
BUGLVL(D_RX) arcnet_dump_packet(dev, recbuf, "rx irq", 0);
arcnet_rx(dev, recbuf);
release_arcbuf(dev, recbuf);
didsomething++;
}
if (status & lp->intmask & RECONflag) {
ACOMMAND(CFLAGScmd | CONFIGclear);
lp->stats.tx_carrier_errors++;
BUGMSG(D_RECON, "Network reconfiguration detected (status=%Xh)\n",
status);
/* MYRECON bit is at bit 7 of diagstatus */
if(diagstatus & 0x80)
BUGMSG(D_RECON,"Put out that recon myself\n");
/* is the RECON info empty or old? */
if (!lp->first_recon || !lp->last_recon ||
jiffies - lp->last_recon > HZ * 10) {
if (lp->network_down)
BUGMSG(D_NORMAL, "reconfiguration detected: cabling restored?\n");
lp->first_recon = lp->last_recon = jiffies;
lp->num_recons = lp->network_down = 0;
BUGMSG(D_DURING, "recon: clearing counters.\n");
} else { /* add to current RECON counter */
lp->last_recon = jiffies;
lp->num_recons++;
BUGMSG(D_DURING, "recon: counter=%d, time=%lds, net=%d\n",
lp->num_recons,
(lp->last_recon - lp->first_recon) / HZ,
lp->network_down);
/* if network is marked up;
* and first_recon and last_recon are 60+ apart;
* and the average no. of recons counted is
* > RECON_THRESHOLD/min;
* then print a warning message.
*/
if (!lp->network_down
&& (lp->last_recon - lp->first_recon) <= HZ * 60
&& lp->num_recons >= RECON_THRESHOLD) {
lp->network_down = 1;
BUGMSG(D_NORMAL, "many reconfigurations detected: cabling problem?\n");
} else if (!lp->network_down
&& lp->last_recon - lp->first_recon > HZ * 60) {
/* reset counters if we've gone for over a minute. */
lp->first_recon = lp->last_recon;
lp->num_recons = 1;
}
}
} else if (lp->network_down && jiffies - lp->last_recon > HZ * 10) {
if (lp->network_down)
BUGMSG(D_NORMAL, "cabling restored?\n");
lp->first_recon = lp->last_recon = 0;
lp->num_recons = lp->network_down = 0;
BUGMSG(D_DURING, "not recon: clearing counters anyway.\n");
}
if(didsomething) {
retval |= IRQ_HANDLED;
}
}
while (--boguscount && didsomething);
BUGMSG(D_DURING, "arcnet_interrupt complete (status=%Xh, count=%d)\n",
ASTATUS(), boguscount);
BUGMSG(D_DURING, "\n");
AINTMASK(0);
udelay(1);
AINTMASK(lp->intmask);
spin_unlock(&lp->lock);
return retval;
}
/*
* This is a generic packet receiver that calls arcnet??_rx depending on the
* protocol ID found.
*/
static void arcnet_rx(struct net_device *dev, int bufnum)
{
struct arcnet_local *lp = dev->priv;
struct archdr pkt;
struct arc_rfc1201 *soft;
int length, ofs;
soft = &pkt.soft.rfc1201;
lp->hw.copy_from_card(dev, bufnum, 0, &pkt, sizeof(ARC_HDR_SIZE));
if (pkt.hard.offset[0]) {
ofs = pkt.hard.offset[0];
length = 256 - ofs;
} else {
ofs = pkt.hard.offset[1];
length = 512 - ofs;
}
/* get the full header, if possible */
if (sizeof(pkt.soft) <= length)
lp->hw.copy_from_card(dev, bufnum, ofs, soft, sizeof(pkt.soft));
else {
memset(&pkt.soft, 0, sizeof(pkt.soft));
lp->hw.copy_from_card(dev, bufnum, ofs, soft, length);
}
BUGMSG(D_DURING, "Buffer #%d: received packet from %02Xh to %02Xh "
"(%d+4 bytes)\n",
bufnum, pkt.hard.source, pkt.hard.dest, length);
lp->stats.rx_packets++;
lp->stats.rx_bytes += length + ARC_HDR_SIZE;
/* call the right receiver for the protocol */
if (arc_proto_map[soft->proto]->is_ip) {
BUGLVL(D_PROTO) {
struct ArcProto
*oldp = arc_proto_map[lp->default_proto[pkt.hard.source]],
*newp = arc_proto_map[soft->proto];
if (oldp != newp) {
BUGMSG(D_PROTO,
"got protocol %02Xh; encap for host %02Xh is now '%c'"
" (was '%c')\n", soft->proto, pkt.hard.source,
newp->suffix, oldp->suffix);
}
}
/* broadcasts will always be done with the last-used encap. */
lp->default_proto[0] = soft->proto;
/* in striking contrast, the following isn't a hack. */
lp->default_proto[pkt.hard.source] = soft->proto;
}
/* call the protocol-specific receiver. */
arc_proto_map[soft->proto]->rx(dev, bufnum, &pkt, length);
}
/*
* Get the current statistics. This may be called with the card open or
* closed.
*/
static struct net_device_stats *arcnet_get_stats(struct net_device *dev)
{
struct arcnet_local *lp = dev->priv;
return &lp->stats;
}
static void null_rx(struct net_device *dev, int bufnum,
struct archdr *pkthdr, int length)
{
BUGMSG(D_PROTO,
"rx: don't know how to deal with proto %02Xh from host %02Xh.\n",
pkthdr->soft.rfc1201.proto, pkthdr->hard.source);
}
static int null_build_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, uint8_t daddr)
{
struct arcnet_local *lp = dev->priv;
BUGMSG(D_PROTO,
"tx: can't build header for encap %02Xh; load a protocol driver.\n",
lp->default_proto[daddr]);
/* always fails */
return 0;
}
/* the "do nothing" prepare_tx function warns that there's nothing to do. */
static int null_prepare_tx(struct net_device *dev, struct archdr *pkt,
int length, int bufnum)
{
struct arcnet_local *lp = dev->priv;
struct arc_hardware newpkt;
BUGMSG(D_PROTO, "tx: no encap for this host; load a protocol driver.\n");
/* send a packet to myself -- will never get received, of course */
newpkt.source = newpkt.dest = dev->dev_addr[0];
/* only one byte of actual data (and it's random) */
newpkt.offset[0] = 0xFF;
lp->hw.copy_to_card(dev, bufnum, 0, &newpkt, ARC_HDR_SIZE);
return 1; /* done */
}
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