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static const char version[] =
"de600.c: $Revision: 1.40 $, Bjorn Ekwall (bj0rn@blox.se)\n";
/*
* de600.c
*
* Linux driver for the D-Link DE-600 Ethernet pocket adapter.
*
* Portions (C) Copyright 1993, 1994 by Bjorn Ekwall
* The Author may be reached as bj0rn@blox.se
*
* Based on adapter information gathered from DE600.ASM by D-Link Inc.,
* as included on disk C in the v.2.11 of PC/TCP from FTP Software.
* For DE600.asm:
* Portions (C) Copyright 1990 D-Link, Inc.
* Copyright, 1988-1992, Russell Nelson, Crynwr Software
*
* Adapted to the sample network driver core for linux,
* written by: Donald Becker <becker@super.org>
* (Now at <becker@scyld.com>)
*
* compile-command:
* "gcc -D__KERNEL__ -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer \
* -m486 -c de600.c
*
**************************************************************/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
**************************************************************/
/* Add more time here if your adapter won't work OK: */
#define DE600_SLOW_DOWN udelay(delay_time)
/*
* If you still have trouble reading/writing to the adapter,
* modify the following "#define": (see <asm/io.h> for more info)
#define REALLY_SLOW_IO
*/
#define SLOW_IO_BY_JUMPING /* Looks "better" than dummy write to port 0x80 :-) */
/*
* If you want to enable automatic continuous checking for the DE600,
* keep this #define enabled.
* It doesn't cost much per packet, so I think it is worth it!
* If you disagree, comment away the #define, and live with it...
*
*/
#define CHECK_LOST_DE600
/*
* Enable this #define if you want the adapter to do a "ifconfig down" on
* itself when we have detected that something is possibly wrong with it.
* The default behaviour is to retry with "adapter_init()" until success.
* This should be used for debugging purposes only.
* (Depends on the CHECK_LOST_DE600 above)
*
*/
#define SHUTDOWN_WHEN_LOST
/*
* See comment at "de600_rspace()"!
* This is an *ugly* hack, but for now it achieves its goal of
* faking a TCP flow-control that will not flood the poor DE600.
*
* Tricks TCP to announce a small max window (max 2 fast packets please :-)
*
* Comment away at your own risk!
*
* Update: Use the more general per-device maxwindow parameter instead.
*/
#undef FAKE_SMALL_MAX
/* use 0 for production, 1 for verification, >2 for debug */
#ifdef DE600_DEBUG
#define PRINTK(x) if (de600_debug >= 2) printk x
#else
#define DE600_DEBUG 0
#define PRINTK(x) /**/
#endif
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <asm/io.h>
#include <linux/in.h>
#include <linux/ptrace.h>
#include <asm/system.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
static unsigned int de600_debug = DE600_DEBUG;
MODULE_PARM(de600_debug, "i");
MODULE_PARM_DESC(de600_debug, "DE-600 debug level (0-2)");
static unsigned int delay_time = 10;
MODULE_PARM(delay_time, "i");
MODULE_PARM_DESC(delay_time, "DE-600 deley on I/O in microseconds");
#ifdef FAKE_SMALL_MAX
static unsigned long de600_rspace(struct sock *sk);
#include <net/sock.h>
#endif
typedef unsigned char byte;
/**************************************************
* *
* Definition of D-Link Ethernet Pocket adapter *
* *
**************************************************/
/*
* D-Link Ethernet pocket adapter ports
*/
/*
* OK, so I'm cheating, but there are an awful lot of
* reads and writes in order to get anything in and out
* of the DE-600 with 4 bits at a time in the parallel port,
* so every saved instruction really helps :-)
*
* That is, I don't care what the device struct says
* but hope that Space.c will keep the rest of the drivers happy.
*/
#ifndef DE600_IO
#define DE600_IO 0x378
#endif
#define DATA_PORT (DE600_IO)
#define STATUS_PORT (DE600_IO + 1)
#define COMMAND_PORT (DE600_IO + 2)
#ifndef DE600_IRQ
#define DE600_IRQ 7
#endif
/*
* It really should look like this, and autoprobing as well...
*
#define DATA_PORT (dev->base_addr + 0)
#define STATUS_PORT (dev->base_addr + 1)
#define COMMAND_PORT (dev->base_addr + 2)
#define DE600_IRQ dev->irq
*/
/*
* D-Link COMMAND_PORT commands
*/
#define SELECT_NIC 0x04 /* select Network Interface Card */
#define SELECT_PRN 0x1c /* select Printer */
#define NML_PRN 0xec /* normal Printer situation */
#define IRQEN 0x10 /* enable IRQ line */
/*
* D-Link STATUS_PORT
*/
#define RX_BUSY 0x80
#define RX_GOOD 0x40
#define TX_FAILED16 0x10
#define TX_BUSY 0x08
/*
* D-Link DATA_PORT commands
* command in low 4 bits
* data in high 4 bits
* select current data nibble with HI_NIBBLE bit
*/
#define WRITE_DATA 0x00 /* write memory */
#define READ_DATA 0x01 /* read memory */
#define STATUS 0x02 /* read status register */
#define COMMAND 0x03 /* write command register (see COMMAND below) */
#define NULL_COMMAND 0x04 /* null command */
#define RX_LEN 0x05 /* read received packet length */
#define TX_ADDR 0x06 /* set adapter transmit memory address */
#define RW_ADDR 0x07 /* set adapter read/write memory address */
#define HI_NIBBLE 0x08 /* read/write the high nibble of data,
or-ed with rest of command */
/*
* command register, accessed through DATA_PORT with low bits = COMMAND
*/
#define RX_ALL 0x01 /* PROMISCUOUS */
#define RX_BP 0x02 /* default: BROADCAST & PHYSICAL ADDRESS */
#define RX_MBP 0x03 /* MULTICAST, BROADCAST & PHYSICAL ADDRESS */
#define TX_ENABLE 0x04 /* bit 2 */
#define RX_ENABLE 0x08 /* bit 3 */
#define RESET 0x80 /* set bit 7 high */
#define STOP_RESET 0x00 /* set bit 7 low */
/*
* data to command register
* (high 4 bits in write to DATA_PORT)
*/
#define RX_PAGE2_SELECT 0x10 /* bit 4, only 2 pages to select */
#define RX_BASE_PAGE 0x20 /* bit 5, always set when specifying RX_ADDR */
#define FLIP_IRQ 0x40 /* bit 6 */
/*
* D-Link adapter internal memory:
*
* 0-2K 1:st transmit page (send from pointer up to 2K)
* 2-4K 2:nd transmit page (send from pointer up to 4K)
*
* 4-6K 1:st receive page (data from 4K upwards)
* 6-8K 2:nd receive page (data from 6K upwards)
*
* 8K+ Adapter ROM (contains magic code and last 3 bytes of Ethernet address)
*/
#define MEM_2K 0x0800 /* 2048 */
#define MEM_4K 0x1000 /* 4096 */
#define MEM_6K 0x1800 /* 6144 */
#define NODE_ADDRESS 0x2000 /* 8192 */
#define RUNT 60 /* Too small Ethernet packet */
/**************************************************
* *
* End of definition *
* *
**************************************************/
/*
* Index to functions, as function prototypes.
*/
/* Routines used internally. (See "convenience macros") */
static byte de600_read_status(struct net_device *dev);
static byte de600_read_byte(unsigned char type, struct net_device *dev);
/* Put in the device structure. */
static int de600_open(struct net_device *dev);
static int de600_close(struct net_device *dev);
static struct net_device_stats *get_stats(struct net_device *dev);
static int de600_start_xmit(struct sk_buff *skb, struct net_device *dev);
/* Dispatch from interrupts. */
static void de600_interrupt(int irq, void *dev_id, struct pt_regs *regs);
static int de600_tx_intr(struct net_device *dev, int irq_status);
static void de600_rx_intr(struct net_device *dev);
/* Initialization */
static void trigger_interrupt(struct net_device *dev);
int de600_probe(struct net_device *dev);
static int adapter_init(struct net_device *dev);
/*
* D-Link driver variables:
*/
static volatile int rx_page;
#define TX_PAGES 2
static volatile int tx_fifo[TX_PAGES];
static volatile int tx_fifo_in;
static volatile int tx_fifo_out;
static volatile int free_tx_pages = TX_PAGES;
static int was_down;
/*
* Convenience macros/functions for D-Link adapter
*/
#define select_prn() outb_p(SELECT_PRN, COMMAND_PORT); DE600_SLOW_DOWN
#define select_nic() outb_p(SELECT_NIC, COMMAND_PORT); DE600_SLOW_DOWN
/* Thanks for hints from Mark Burton <markb@ordern.demon.co.uk> */
#define de600_put_byte(data) ( \
outb_p(((data) << 4) | WRITE_DATA , DATA_PORT), \
outb_p(((data) & 0xf0) | WRITE_DATA | HI_NIBBLE, DATA_PORT))
/*
* The first two outb_p()'s below could perhaps be deleted if there
* would be more delay in the last two. Not certain about it yet...
*/
#define de600_put_command(cmd) ( \
outb_p(( rx_page << 4) | COMMAND , DATA_PORT), \
outb_p(( rx_page & 0xf0) | COMMAND | HI_NIBBLE, DATA_PORT), \
outb_p(((rx_page | cmd) << 4) | COMMAND , DATA_PORT), \
outb_p(((rx_page | cmd) & 0xf0) | COMMAND | HI_NIBBLE, DATA_PORT))
#define de600_setup_address(addr,type) ( \
outb_p((((addr) << 4) & 0xf0) | type , DATA_PORT), \
outb_p(( (addr) & 0xf0) | type | HI_NIBBLE, DATA_PORT), \
outb_p((((addr) >> 4) & 0xf0) | type , DATA_PORT), \
outb_p((((addr) >> 8) & 0xf0) | type | HI_NIBBLE, DATA_PORT))
#define rx_page_adr() ((rx_page & RX_PAGE2_SELECT)?(MEM_6K):(MEM_4K))
/* Flip bit, only 2 pages */
#define next_rx_page() (rx_page ^= RX_PAGE2_SELECT)
#define tx_page_adr(a) (((a) + 1) * MEM_2K)
static inline byte
de600_read_status(struct net_device *dev)
{
byte status;
outb_p(STATUS, DATA_PORT);
status = inb(STATUS_PORT);
outb_p(NULL_COMMAND | HI_NIBBLE, DATA_PORT);
return status;
}
static inline byte
de600_read_byte(unsigned char type, struct net_device *dev) { /* dev used by macros */
byte lo;
(void)outb_p((type), DATA_PORT);
lo = ((unsigned char)inb(STATUS_PORT)) >> 4;
(void)outb_p((type) | HI_NIBBLE, DATA_PORT);
return ((unsigned char)inb(STATUS_PORT) & (unsigned char)0xf0) | lo;
}
/*
* Open/initialize the board. This is called (in the current kernel)
* after booting when 'ifconfig <dev->name> $IP_ADDR' is run (in rc.inet1).
*
* 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 a non-reboot way to recover if something goes wrong.
*/
static int
de600_open(struct net_device *dev)
{
int ret = request_irq(DE600_IRQ, de600_interrupt, 0, dev->name, dev);
if (ret) {
printk ("%s: unable to get IRQ %d\n", dev->name, DE600_IRQ);
return ret;
}
if (adapter_init(dev))
return -EIO;
return 0;
}
/*
* The inverse routine to de600_open().
*/
static int
de600_close(struct net_device *dev)
{
select_nic();
rx_page = 0;
de600_put_command(RESET);
de600_put_command(STOP_RESET);
de600_put_command(0);
select_prn();
if (netif_running(dev)) { /* perhaps not needed? */
free_irq(DE600_IRQ, dev);
}
return 0;
}
static struct net_device_stats *
get_stats(struct net_device *dev)
{
return (struct net_device_stats *)(dev->priv);
}
static inline void
trigger_interrupt(struct net_device *dev)
{
de600_put_command(FLIP_IRQ);
select_prn();
DE600_SLOW_DOWN;
select_nic();
de600_put_command(0);
}
/*
* Copy a buffer to the adapter transmit page memory.
* Start sending.
*/
static int
de600_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
unsigned long flags;
int transmit_from;
int len;
int tickssofar;
byte *buffer = skb->data;
if (free_tx_pages <= 0) { /* Do timeouts, to avoid hangs. */
tickssofar = jiffies - dev->trans_start;
if (tickssofar < 5)
return 1;
/* else */
printk("%s: transmit timed out (%d), %s?\n",
dev->name,
tickssofar,
"network cable problem"
);
/* Restart the adapter. */
if (adapter_init(dev)) {
return 1;
}
}
/* Start real output */
PRINTK(("de600_start_xmit:len=%d, page %d/%d\n", skb->len, tx_fifo_in, free_tx_pages));
if ((len = skb->len) < RUNT)
len = RUNT;
save_flags(flags);
cli();
select_nic();
tx_fifo[tx_fifo_in] = transmit_from = tx_page_adr(tx_fifo_in) - len;
tx_fifo_in = (tx_fifo_in + 1) % TX_PAGES; /* Next free tx page */
#ifdef CHECK_LOST_DE600
/* This costs about 40 instructions per packet... */
de600_setup_address(NODE_ADDRESS, RW_ADDR);
de600_read_byte(READ_DATA, dev);
if (was_down || (de600_read_byte(READ_DATA, dev) != 0xde)) {
if (adapter_init(dev)) {
restore_flags(flags);
return 1;
}
}
#endif
de600_setup_address(transmit_from, RW_ADDR);
for ( ; len > 0; --len, ++buffer)
de600_put_byte(*buffer);
if (free_tx_pages-- == TX_PAGES) { /* No transmission going on */
dev->trans_start = jiffies;
netif_start_queue(dev); /* allow more packets into adapter */
/* Send page and generate a faked interrupt */
de600_setup_address(transmit_from, TX_ADDR);
de600_put_command(TX_ENABLE);
}
else {
if (free_tx_pages)
netif_start_queue(dev);
else
netif_stop_queue(dev);
select_prn();
}
restore_flags(flags);
#ifdef FAKE_SMALL_MAX
/* This will "patch" the socket TCP proto at an early moment */
if (skb->sk && (skb->sk->protocol == IPPROTO_TCP) &&
(skb->sk->prot->rspace != &de600_rspace))
skb->sk->prot->rspace = de600_rspace; /* Ugh! */
#endif
dev_kfree_skb (skb);
return 0;
}
/*
* The typical workload of the driver:
* Handle the network interface interrupts.
*/
static void
de600_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
struct net_device *dev = dev_id;
byte irq_status;
int retrig = 0;
int boguscount = 0;
/* This might just as well be deleted now, no crummy drivers present :-) */
if ((dev == NULL) || (DE600_IRQ != irq)) {
printk("%s: bogus interrupt %d\n", dev?dev->name:"DE-600", irq);
return;
}
select_nic();
irq_status = de600_read_status(dev);
do {
PRINTK(("de600_interrupt (%02X)\n", irq_status));
if (irq_status & RX_GOOD)
de600_rx_intr(dev);
else if (!(irq_status & RX_BUSY))
de600_put_command(RX_ENABLE);
/* Any transmission in progress? */
if (free_tx_pages < TX_PAGES)
retrig = de600_tx_intr(dev, irq_status);
else
retrig = 0;
irq_status = de600_read_status(dev);
} while ( (irq_status & RX_GOOD) || ((++boguscount < 100) && retrig) );
/*
* Yeah, it _looks_ like busy waiting, smells like busy waiting
* and I know it's not PC, but please, it will only occur once
* in a while and then only for a loop or so (< 1ms for sure!)
*/
/* Enable adapter interrupts */
select_prn();
if (retrig)
trigger_interrupt(dev);
return;
}
static int
de600_tx_intr(struct net_device *dev, int irq_status)
{
/*
* Returns 1 if tx still not done
*/
/* Check if current transmission is done yet */
if (irq_status & TX_BUSY)
return 1; /* tx not done, try again */
/* else */
/* If last transmission OK then bump fifo index */
if (!(irq_status & TX_FAILED16)) {
tx_fifo_out = (tx_fifo_out + 1) % TX_PAGES;
++free_tx_pages;
((struct net_device_stats *)(dev->priv))->tx_packets++;
netif_wake_queue(dev);
}
/* More to send, or resend last packet? */
if ((free_tx_pages < TX_PAGES) || (irq_status & TX_FAILED16)) {
dev->trans_start = jiffies;
de600_setup_address(tx_fifo[tx_fifo_out], TX_ADDR);
de600_put_command(TX_ENABLE);
return 1;
}
/* else */
return 0;
}
/*
* We have a good packet, get it out of the adapter.
*/
static void
de600_rx_intr(struct net_device *dev)
{
struct sk_buff *skb;
unsigned long flags;
int i;
int read_from;
int size;
register unsigned char *buffer;
save_flags(flags);
cli();
/* Get size of received packet */
size = de600_read_byte(RX_LEN, dev); /* low byte */
size += (de600_read_byte(RX_LEN, dev) << 8); /* high byte */
size -= 4; /* Ignore trailing 4 CRC-bytes */
/* Tell adapter where to store next incoming packet, enable receiver */
read_from = rx_page_adr();
next_rx_page();
de600_put_command(RX_ENABLE);
restore_flags(flags);
if ((size < 32) || (size > 1535)) {
printk("%s: Bogus packet size %d.\n", dev->name, size);
if (size > 10000)
adapter_init(dev);
return;
}
skb = dev_alloc_skb(size+2);
if (skb == NULL) {
printk("%s: Couldn't allocate a sk_buff of size %d.\n",
dev->name, size);
return;
}
/* else */
skb->dev = dev;
skb_reserve(skb,2); /* Align */
/* 'skb->data' points to the start of sk_buff data area. */
buffer = skb_put(skb,size);
/* copy the packet into the buffer */
de600_setup_address(read_from, RW_ADDR);
for (i = size; i > 0; --i, ++buffer)
*buffer = de600_read_byte(READ_DATA, dev);
skb->protocol=eth_type_trans(skb,dev);
netif_rx(skb);
/* update stats */
dev->last_rx = jiffies;
((struct net_device_stats *)(dev->priv))->rx_packets++; /* count all receives */
((struct net_device_stats *)(dev->priv))->rx_bytes += size; /* count all received bytes */
/*
* If any worth-while packets have been received, netif_rx()
* has done a mark_bh(INET_BH) for us and will work on them
* when we get to the bottom-half routine.
*/
}
int __init
de600_probe(struct net_device *dev)
{
int i;
static struct net_device_stats de600_netstats;
/*dev->priv = kmalloc(sizeof(struct net_device_stats), GFP_KERNEL);*/
SET_MODULE_OWNER(dev);
printk("%s: D-Link DE-600 pocket adapter", dev->name);
/* Alpha testers must have the version number to report bugs. */
if (de600_debug > 1)
printk(version);
/* probe for adapter */
rx_page = 0;
select_nic();
(void)de600_read_status(dev);
de600_put_command(RESET);
de600_put_command(STOP_RESET);
if (de600_read_status(dev) & 0xf0) {
printk(": not at I/O %#3x.\n", DATA_PORT);
return -ENODEV;
}
/*
* Maybe we found one,
* have to check if it is a D-Link DE-600 adapter...
*/
/* Get the adapter ethernet address from the ROM */
de600_setup_address(NODE_ADDRESS, RW_ADDR);
for (i = 0; i < ETH_ALEN; i++) {
dev->dev_addr[i] = de600_read_byte(READ_DATA, dev);
dev->broadcast[i] = 0xff;
}
/* Check magic code */
if ((dev->dev_addr[1] == 0xde) && (dev->dev_addr[2] == 0x15)) {
/* OK, install real address */
dev->dev_addr[0] = 0x00;
dev->dev_addr[1] = 0x80;
dev->dev_addr[2] = 0xc8;
dev->dev_addr[3] &= 0x0f;
dev->dev_addr[3] |= 0x70;
} else {
printk(" not identified in the printer port\n");
return -ENODEV;
}
#if 0 /* Not yet */
if (check_region(DE600_IO, 3)) {
printk(", port 0x%x busy\n", DE600_IO);
return -EBUSY;
}
#endif
request_region(DE600_IO, 3, "de600");
printk(", Ethernet Address: %02X", dev->dev_addr[0]);
for (i = 1; i < ETH_ALEN; i++)
printk(":%02X",dev->dev_addr[i]);
printk("\n");
/* Initialize the device structure. */
dev->priv = &de600_netstats;
memset(dev->priv, 0, sizeof(struct net_device_stats));
dev->get_stats = get_stats;
dev->open = de600_open;
dev->stop = de600_close;
dev->hard_start_xmit = &de600_start_xmit;
ether_setup(dev);
dev->flags&=~IFF_MULTICAST;
select_prn();
return 0;
}
static int
adapter_init(struct net_device *dev)
{
int i;
long flags;
save_flags(flags);
cli();
select_nic();
rx_page = 0; /* used by RESET */
de600_put_command(RESET);
de600_put_command(STOP_RESET);
#ifdef CHECK_LOST_DE600
/* Check if it is still there... */
/* Get the some bytes of the adapter ethernet address from the ROM */
de600_setup_address(NODE_ADDRESS, RW_ADDR);
de600_read_byte(READ_DATA, dev);
if ((de600_read_byte(READ_DATA, dev) != 0xde) ||
(de600_read_byte(READ_DATA, dev) != 0x15)) {
/* was: if (de600_read_status(dev) & 0xf0) { */
printk("Something has happened to the DE-600! Please check it"
#ifdef SHUTDOWN_WHEN_LOST
" and do a new ifconfig"
#endif /* SHUTDOWN_WHEN_LOST */
"!\n");
#ifdef SHUTDOWN_WHEN_LOST
/* Goodbye, cruel world... */
dev->flags &= ~IFF_UP;
de600_close(dev);
#endif /* SHUTDOWN_WHEN_LOST */
was_down = 1;
netif_stop_queue(dev); /* Transmit busy... */
restore_flags(flags);
return 1; /* failed */
}
#endif /* CHECK_LOST_DE600 */
if (was_down) {
printk("Thanks, I feel much better now!\n");
was_down = 0;
}
netif_start_queue(dev);
tx_fifo_in = 0;
tx_fifo_out = 0;
free_tx_pages = TX_PAGES;
/* set the ether address. */
de600_setup_address(NODE_ADDRESS, RW_ADDR);
for (i = 0; i < ETH_ALEN; i++)
de600_put_byte(dev->dev_addr[i]);
/* where to start saving incoming packets */
rx_page = RX_BP | RX_BASE_PAGE;
de600_setup_address(MEM_4K, RW_ADDR);
/* Enable receiver */
de600_put_command(RX_ENABLE);
select_prn();
restore_flags(flags);
return 0; /* OK */
}
#ifdef FAKE_SMALL_MAX
/*
* The new router code (coming soon 8-) ) will fix this properly.
*/
#define DE600_MIN_WINDOW 1024
#define DE600_MAX_WINDOW 2048
#define DE600_TCP_WINDOW_DIFF 1024
/*
* Copied from "net/inet/sock.c"
*
* Sets a lower max receive window in order to achieve <= 2
* packets arriving at the adapter in fast succession.
* (No way that a DE-600 can keep up with a net saturated
* with packets homing in on it :-( )
*
* Since there are only 2 receive buffers in the DE-600
* and it takes some time to copy from the adapter,
* this is absolutely necessary for any TCP performance whatsoever!
*
* Note that the returned window info will never be smaller than
* DE600_MIN_WINDOW, i.e. 1024
* This differs from the standard function, that can return an
* arbitrarily small window!
*/
static unsigned long
de600_rspace(struct sock *sk)
{
int amt;
if (sk != NULL) {
/*
* Hack! You might want to play with commenting away the following line,
* if you know what you do!
sk->max_unacked = DE600_MAX_WINDOW - DE600_TCP_WINDOW_DIFF;
*/
if (atomic_read(&sk->rmem_alloc) >= sk->rcvbuf-2*DE600_MIN_WINDOW) return(0);
amt = min_t(int, (sk->rcvbuf-atomic_read(&sk->rmem_alloc))/2/*-DE600_MIN_WINDOW*/, DE600_MAX_WINDOW);
if (amt < 0) return(0);
return(amt);
}
return(0);
}
#endif
#ifdef MODULE
static struct net_device de600_dev;
int
init_module(void)
{
de600_dev.init = de600_probe;
if (register_netdev(&de600_dev) != 0)
return -EIO;
return 0;
}
void
cleanup_module(void)
{
unregister_netdev(&de600_dev);
release_region(DE600_IO, 3);
}
#endif /* MODULE */
MODULE_LICENSE("GPL");
/*
* Local variables:
* kernel-compile-command: "gcc -D__KERNEL__ -Ilinux/include -I../../net/inet -Wall -Wstrict-prototypes -O2 -m486 -c de600.c"
* module-compile-command: "gcc -D__KERNEL__ -DMODULE -Ilinux/include -I../../net/inet -Wall -Wstrict-prototypes -O2 -m486 -c de600.c"
* compile-command: "gcc -D__KERNEL__ -DMODULE -Ilinux/include -I../../net/inet -Wall -Wstrict-prototypes -O2 -m486 -c de600.c"
* End:
*/
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