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- static char *version =
- "d_link.c: $Revision: 0.32 $, Bjorn Ekwall (bj0rn@blox.se)\n";
- /*
- * d_link.c
- *
- * Linux driver for the D-Link DE-600 Ethernet pocket adapter.
- *
- * Portions (C) Copyright 1993 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>
- * C/O Supercomputing Research Ctr., 17100 Science Dr., Bowie MD 20715
- *
- * compile-command:
- * "gcc -D__KERNEL__ -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer \
- * -m486 -DD_LINK_IO=0x378 -DD_LINK_IRQ=7 -UD_LINK_DEBUG -S d_link.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 another "; SLOW_DOWN_IO" here if your adapter won't work OK: */
- #define D_LINK_SLOW_DOWN SLOW_DOWN_IO; SLOW_DOWN_IO; SLOW_DOWN_IO
-
- /*
- * 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 :-) */
-
- /*
- * For fix to TCP "slowdown", take a look at the "#define D_LINK_MAX_WINDOW"
- * near the end of the file...
- */
-
- /* use 0 for production, 1 for verification, >2 for debug */
- #ifdef D_LINK_DEBUG
- #define PRINTK(x) if (d_link_debug >= 2) printk x
- #else
- #define D_LINK_DEBUG 0
- #define PRINTK(x) /**/
- #endif
- static unsigned int d_link_debug = D_LINK_DEBUG;
-
- #include <linux/config.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 <asm/io.h>
- #include <netinet/in.h>
- #include <linux/ptrace.h>
- #include <asm/system.h>
- #include <errno.h>
-
- #include "inet.h"
- #include "dev.h"
- #include "eth.h"
- #include "ip.h"
- #include "route.h"
- #include "protocol.h"
- #include "tcp.h"
- #include "skbuff.h"
- #include "sock.h"
- #include "arp.h"
-
- #define netstats enet_statistics
-
- #ifndef HAVE_ALLOC_SKB
- #define alloc_skb(size,pri) (struct sk_buff *)kmalloc(size,pri)
- #endif
-
- /**************************************************
- * *
- * 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 D_LINK_IO
- #define D_LINK_IO 0x378
- #endif
-
- #define DATA_PORT (D_LINK_IO)
- #define STATUS_PORT (D_LINK_IO + 1)
- #define COMMAND_PORT (D_LINK_IO + 2)
-
- #ifndef D_LINK_IRQ
- #define D_LINK_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 D_LINK_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 /* PROMISCIOUS */
- #define RX_BP 0x02 /* default: BROADCAST & PHYSICAL ADRESS */
- #define RX_MBP 0x03 /* MULTICAST, BROADCAST & PHYSICAL ADRESS */
-
- #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.
- */
-
- /* For tricking tcp.c to announce a small max window (max 2 fast packets please :-) */
- static unsigned long d_link_rspace(struct sock *sk);
-
- /* Routines used internally. (See "convenience macros") */
- static int d_link_read_status(struct device *dev);
- static unsigned char d_link_read_byte(unsigned char type, struct device *dev);
-
- /* Put in the device structure. */
- static int d_link_open(struct device *dev);
- static int d_link_close(struct device *dev);
- static struct netstats *get_stats(struct device *dev);
- static int d_link_start_xmit(struct sk_buff *skb, struct device *dev);
-
- /* Dispatch from interrupts. */
- static void d_link_interrupt(int reg_ptr);
- static int d_link_tx_intr(struct device *dev, int irq_status);
- static void d_link_rx_intr(struct device *dev);
-
- /* Initialization */
- static void trigger_interrupt(struct device *dev);
- int d_link_init(struct device *dev);
- static void adapter_init(struct device *dev);
-
- /*
- * D-Link driver variables:
- */
- extern struct device *irq2dev_map[16];
- static volatile int rx_page = 0;
-
- #define TX_PAGES 2
- static volatile int tx_fifo[TX_PAGES];
- static volatile int tx_fifo_in = 0;
- static volatile int tx_fifo_out = 0;
- static volatile int free_tx_pages = TX_PAGES;
-
- /*
- * Convenience macros/functions for D-Link adapter
- */
-
- #define select_prn() outb_p(SELECT_PRN, COMMAND_PORT); D_LINK_SLOW_DOWN
- #define select_nic() outb_p(SELECT_NIC, COMMAND_PORT); D_LINK_SLOW_DOWN
-
- /* Thanks for hints from Mark Burton <markb@ordern.demon.co.uk> */
- #define d_link_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 d_link_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 d_link_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 int
- d_link_read_status(struct device *dev)
- {
- int status;
-
- outb_p(STATUS, DATA_PORT);
- status = inb(STATUS_PORT);
- outb_p(NULL_COMMAND | HI_NIBBLE, DATA_PORT);
-
- return status;
- }
-
- static inline unsigned char
- d_link_read_byte(unsigned char type, struct device *dev) { /* dev used by macros */
- unsigned char 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
- d_link_open(struct device *dev)
- {
- extern struct proto tcp_prot;
-
- if (request_irq(D_LINK_IRQ, d_link_interrupt)) {
- printk ("%s: unable to get IRQ %d\n", dev->name, D_LINK_IRQ);
- return 1;
- }
- irq2dev_map[D_LINK_IRQ] = dev;
-
- adapter_init(dev);
-
- /*
- * Yes, I know!
- * This is really not nice, but since a machine that uses DE-600
- * rarely uses any other TCP/IP connection device simultaneously,
- * this hack shouldn't really slow anything up.
- * (I don't know about slip though... but it won't break it)
- *
- * This fix is better than changing in tcp.h IMHO
- */
- tcp_prot.rspace = d_link_rspace; /* was: sock_rspace */
-
- return 0;
- }
-
- /*
- * The inverse routine to d_link_open().
- */
- static int
- d_link_close(struct device *dev)
- {
- select_nic();
- rx_page = 0;
- d_link_put_command(RESET);
- d_link_put_command(STOP_RESET);
- d_link_put_command(0);
- select_prn();
-
- free_irq(D_LINK_IRQ);
- irq2dev_map[D_LINK_IRQ] = NULL;
- dev->start = 0;
- tcp_prot.rspace = sock_rspace; /* see comment above! */
-
- return 0;
- }
-
- static struct netstats *
- get_stats(struct device *dev)
- {
- return (struct netstats *)(dev->priv);
- }
-
- static inline void
- trigger_interrupt(struct device *dev)
- {
- d_link_put_command(FLIP_IRQ);
- select_prn();
- D_LINK_SLOW_DOWN;
- select_nic();
- d_link_put_command(0);
- }
-
- /*
- * Copy a buffer to the adapter transmit page memory.
- * Start sending.
- */
- static int
- d_link_start_xmit(struct sk_buff *skb, struct device *dev)
- {
- int transmit_from;
- int len;
- int tickssofar;
- unsigned char *buffer = skb->data;
-
- /*
- * If some higher layer thinks we've missed a
- * tx-done interrupt we are passed NULL.
- * Caution: dev_tint() handles the cli()/sti() itself.
- */
-
- if (skb == NULL) {
- dev_tint(dev);
- return 0;
- }
-
- /* For ethernet, fill in the header (hardware addresses) with an arp. */
- if (!skb->arp)
- if(dev->rebuild_header(skb->data, dev)) {
- skb->dev = dev;
- arp_queue (skb);
- return 0;
- }
- skb->arp = 1;
-
- 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. */
- adapter_init(dev);
- }
-
- /* Start real output */
- PRINTK(("d_link_start_xmit:len=%d, page %d/%d\n", skb->len, tx_fifo_in, free_tx_pages));
-
- if ((len = skb->len) < RUNT)
- len = RUNT;
-
- 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 */
-
- d_link_setup_address(transmit_from, RW_ADDR);
- for ( ; len > 0; --len, ++buffer)
- d_link_put_byte(*buffer);
-
- if (free_tx_pages-- == TX_PAGES) { /* No transmission going on */
- dev->trans_start = jiffies;
- dev->tbusy = 0; /* allow more packets into adapter */
- /* Send page and generate an interrupt */
- d_link_setup_address(transmit_from, TX_ADDR);
- d_link_put_command(TX_ENABLE);
- }
- else {
- dev->tbusy = !free_tx_pages;
- select_prn();
- }
-
- sti(); /* interrupts back on */
-
- if (skb->free)
- kfree_skb (skb, FREE_WRITE);
-
- return 0;
- }
-
- /*
- * The typical workload of the driver:
- * Handle the network interface interrupts.
- */
- static void
- d_link_interrupt(int reg_ptr)
- {
- int irq = -(((struct pt_regs *)reg_ptr)->orig_eax+2);
- struct device *dev = irq2dev_map[irq];
- unsigned char irq_status;
- int retrig = 0;
- int boguscount = 0;
-
- /* This might just as well be deleted now, no crummy drivers present :-) */
- if ((dev == NULL) || (dev->start == 0) || (D_LINK_IRQ != irq)) {
- printk("%s: bogus interrupt %d\n", dev?dev->name:"DE-600", irq);
- return;
- }
-
- dev->interrupt = 1;
- select_nic();
- irq_status = d_link_read_status(dev);
-
- do {
- PRINTK(("d_link_interrupt (%2.2X)\n", irq_status));
-
- if (irq_status & RX_GOOD)
- d_link_rx_intr(dev);
- else if (!(irq_status & RX_BUSY))
- d_link_put_command(RX_ENABLE);
-
- /* Any transmission in progress? */
- if (free_tx_pages < TX_PAGES)
- retrig = d_link_tx_intr(dev, irq_status);
- else
- retrig = 0;
-
- irq_status = d_link_read_status(dev);
- } while ( (irq_status & RX_GOOD) || ((++boguscount < 10) && 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 */
- dev->interrupt = 0;
- select_prn();
-
- if (retrig)
- trigger_interrupt(dev);
-
- sti();
- return;
- }
-
- static int
- d_link_tx_intr(struct device *dev, int irq_status)
- {
- /*
- * Returns 1 if tx still not done
- */
-
- mark_bh(INET_BH);
- /* 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 netstats *)(dev->priv))->tx_packets++;
- dev->tbusy = 0;
- }
-
- /* More to send, or resend last packet? */
- if ((free_tx_pages < TX_PAGES) || (irq_status & TX_FAILED16)) {
- dev->trans_start = jiffies;
- d_link_setup_address(tx_fifo[tx_fifo_out], TX_ADDR);
- d_link_put_command(TX_ENABLE);
- return 1;
- }
- /* else */
-
- return 0;
- }
-
- /*
- * We have a good packet, get it out of the adapter.
- */
- static void
- d_link_rx_intr(struct device *dev)
- {
- struct sk_buff *skb;
- int i;
- int read_from;
- int size;
- int sksize;
- register unsigned char *buffer;
-
- cli();
- /* Get size of received packet */
- size = d_link_read_byte(RX_LEN, dev); /* low byte */
- size += (d_link_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();
- d_link_put_command(RX_ENABLE);
- sti();
-
- if ((size < 32) || (size > 1535))
- printk("%s: Bogus packet size %d.\n", dev->name, size);
-
- sksize = sizeof(struct sk_buff) + size;
- skb = alloc_skb(sksize, GFP_ATOMIC);
- sti();
- if (skb == NULL) {
- printk("%s: Couldn't allocate a sk_buff of size %d.\n",
- dev->name, sksize);
- return;
- }
- /* else */
-
- skb->lock = 0;
- skb->mem_len = sksize;
- skb->mem_addr = skb;
- /* 'skb->data' points to the start of sk_buff data area. */
- buffer = skb->data;
-
- /* copy the packet into the buffer */
- d_link_setup_address(read_from, RW_ADDR);
- for (i = size; i > 0; --i, ++buffer)
- *buffer = d_link_read_byte(READ_DATA, dev);
-
- ((struct netstats *)(dev->priv))->rx_packets++; /* count all receives */
-
- if (dev_rint((unsigned char *)skb, size, IN_SKBUFF, dev))
- printk("%s: receive buffers full.\n", dev->name);
- /*
- * If any worth-while packets have been received, dev_rint()
- * has done a mark_bh(INET_BH) for us and will work on them
- * when we get to the bottom-half routine.
- */
- }
-
- int
- d_link_init(struct device *dev)
- {
- int i;
-
- printk("%s: D-Link DE-600 pocket adapter", dev->name);
- /* Alpha testers must have the version number to report bugs. */
- if (d_link_debug > 1)
- printk(version);
-
- /* probe for adapter */
- rx_page = 0;
- select_nic();
- (void)d_link_read_status(dev);
- d_link_put_command(RESET);
- d_link_put_command(STOP_RESET);
- if (d_link_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 */
- d_link_setup_address(NODE_ADDRESS, RW_ADDR);
- for (i = 0; i < ETH_ALEN; i++) {
- dev->dev_addr[i] = d_link_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;
- }
-
- printk(", Ethernet Address: %2.2X", dev->dev_addr[0]);
- for (i = 1; i < ETH_ALEN; i++)
- printk(":%2.2X",dev->dev_addr[i]);
- printk("\n");
-
- /* Initialize the device structure. */
- dev->priv = kmalloc(sizeof(struct netstats), GFP_KERNEL);
- memset(dev->priv, 0, sizeof(struct netstats));
-
- for (i = 0; i < DEV_NUMBUFFS; i++)
- dev->buffs[i] = NULL;
-
- dev->get_stats = get_stats;
- dev->hard_header = eth_header;
- dev->add_arp = eth_add_arp;
- dev->queue_xmit = dev_queue_xmit;
- dev->rebuild_header = eth_rebuild_header;
- dev->type_trans = eth_type_trans;
-
- dev->open = d_link_open;
- dev->stop = d_link_close;
- dev->hard_start_xmit = &d_link_start_xmit;
-
- /* These are ethernet specific. */
- dev->type = ARPHRD_ETHER;
- dev->hard_header_len = ETH_HLEN;
- dev->mtu = 1500; /* eth_mtu */
- dev->addr_len = ETH_ALEN;
-
- /* New-style flags. */
- dev->flags = IFF_BROADCAST;
- dev->family = AF_INET;
- dev->pa_addr = 0;
- dev->pa_brdaddr = 0;
- dev->pa_mask = 0;
- dev->pa_alen = sizeof(unsigned long);
-
- select_prn();
- return 0;
- }
-
- static void
- adapter_init(struct device *dev)
- {
- int i;
-
- cli();
- dev->tbusy = 0; /* Transmit busy... */
- dev->interrupt = 0;
- dev->start = 1;
-
- select_nic();
- rx_page = 0; /* used by RESET */
- d_link_put_command(RESET);
- d_link_put_command(STOP_RESET);
-
- tx_fifo_in = 0;
- tx_fifo_out = 0;
- free_tx_pages = TX_PAGES;
-
- /* set the ether address. */
- d_link_setup_address(NODE_ADDRESS, RW_ADDR);
- for (i = 0; i < ETH_ALEN; i++)
- d_link_put_byte(dev->dev_addr[i]);
-
- /* where to start saving incoming packets */
- rx_page = RX_BP | RX_BASE_PAGE;
- d_link_setup_address(MEM_4K, RW_ADDR);
- /* Enable receiver */
- d_link_put_command(RX_ENABLE);
- select_prn();
- sti();
- }
-
- #define D_LINK_MIN_WINDOW 1024
- #define D_LINK_MAX_WINDOW 2048
- #define D_LINK_TCP_WINDOW_DIFF 1024
- /*
- * Copied from 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 cope with an ethernet saturated with its packets :-)
- *
- * 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!
- *
- */
- #define min(a,b) ((a)<(b)?(a):(b))
- static unsigned long
- d_link_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 = D_LINK_MAX_WINDOW - D_LINK_TCP_WINDOW_DIFF;
-
- if (sk->rmem_alloc >= SK_RMEM_MAX-2*D_LINK_MIN_WINDOW) return(0);
- amt = min((SK_RMEM_MAX-sk->rmem_alloc)/2-D_LINK_MIN_WINDOW, D_LINK_MAX_WINDOW);
- if (amt < 0) return(0);
- return(amt);
- }
- return(0);
- }
-