amd8111e.c

/* Advanced  Micro Devices Inc. AMD8111E Linux Network Driver 
 * Copyright (C) 2004 Advanced Micro Devices 
 *
 * 
 * Copyright 2001,2002 Jeff Garzik <jgarzik@mandrakesoft.com> [ 8139cp.c,tg3.c ]
 * Copyright (C) 2001, 2002 David S. Miller (davem@redhat.com)[ tg3.c]
 * Copyright 1996-1999 Thomas Bogendoerfer [ pcnet32.c ]
 * Derived from the lance driver written 1993,1994,1995 by Donald Becker.
 * Copyright 1993 United States Government as represented by the
 *	Director, National Security Agency.[ pcnet32.c ]
 * Carsten Langgaard, carstenl@mips.com [ pcnet32.c ]
 * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
 *
 * 
 * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 
 * USA
  
Module Name:

	amd8111e.c

Abstract:
	
 	 AMD8111 based 10/100 Ethernet Controller Driver. 

Environment:

	Kernel Mode

Revision History:
 	3.0.0
	   Initial Revision.
	3.0.1
	 1. Dynamic interrupt coalescing.
	 2. Removed prev_stats.
	 3. MII support.
	 4. Dynamic IPG support
	3.0.2  05/29/2003
	 1. Bug fix: Fixed failure to send jumbo packets larger than 4k.
	 2. Bug fix: Fixed VLAN support failure.
	 3. Bug fix: Fixed receive interrupt coalescing bug.
	 4. Dynamic IPG support is disabled by default.
	3.0.3 06/05/2003
	 1. Bug fix: Fixed failure to close the interface if SMP is enabled.
	3.0.4 12/09/2003
	 1. Added set_mac_address routine for bonding driver support.
	 2. Tested the driver for bonding support
	 3. Bug fix: Fixed mismach in actual receive buffer lenth and lenth 
	    indicated to the h/w.
	 4. Modified amd8111e_rx() routine to receive all the received packets 
	    in the first interrupt.
	 5. Bug fix: Corrected  rx_errors  reported in get_stats() function.
	3.0.5 03/22/2004
	 1. Added NAPI support  

*/


#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/if_vlan.h>
#include <linux/ctype.h>	
#include <linux/crc32.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/byteorder.h>
#include <asm/uaccess.h>

#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
#define AMD8111E_VLAN_TAG_USED 1
#else
#define AMD8111E_VLAN_TAG_USED 0
#endif

#include "amd8111e.h"
#define MODULE_NAME	"amd8111e"
#define MODULE_VERS	"3.0.5"
MODULE_AUTHOR("Advanced Micro Devices, Inc.");
MODULE_DESCRIPTION ("AMD8111 based 10/100 Ethernet Controller. Driver Version 3.0.3");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, amd8111e_pci_tbl);
module_param_array(speed_duplex, int, NULL, 0);
MODULE_PARM_DESC(speed_duplex, "Set device speed and duplex modes, 0: Auto Negotitate, 1: 10Mbps Half Duplex, 2: 10Mbps Full Duplex, 3: 100Mbps Half Duplex, 4: 100Mbps Full Duplex");
module_param_array(coalesce, bool, NULL, 0);
MODULE_PARM_DESC(coalesce, "Enable or Disable interrupt coalescing, 1: Enable, 0: Disable");
module_param_array(dynamic_ipg, bool, NULL, 0);
MODULE_PARM_DESC(dynamic_ipg, "Enable or Disable dynamic IPG, 1: Enable, 0: Disable");

static struct pci_device_id amd8111e_pci_tbl[] = {
		
	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD8111E_7462,
	 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0UL },
	{ 0, }

};
/* 
This function will read the PHY registers.
*/
static int amd8111e_read_phy(struct amd8111e_priv* lp, int phy_id, int reg, u32* val)
{
	void __iomem *mmio = lp->mmio;
	unsigned int reg_val;
	unsigned int repeat= REPEAT_CNT;

	reg_val = readl(mmio + PHY_ACCESS);
	while (reg_val & PHY_CMD_ACTIVE)
		reg_val = readl( mmio + PHY_ACCESS );

	writel( PHY_RD_CMD | ((phy_id & 0x1f) << 21) |
			   ((reg & 0x1f) << 16),  mmio +PHY_ACCESS);
	do{
		reg_val = readl(mmio + PHY_ACCESS);
		udelay(30);  /* It takes 30 us to read/write data */
	} while (--repeat && (reg_val & PHY_CMD_ACTIVE));
	if(reg_val & PHY_RD_ERR)
		goto err_phy_read;
	
	*val = reg_val & 0xffff;
	return 0;
err_phy_read:	
	*val = 0;
	return -EINVAL;
	
}

/* 
This function will write into PHY registers. 
*/
static int amd8111e_write_phy(struct amd8111e_priv* lp,int phy_id, int reg, u32 val)
{
	unsigned int repeat = REPEAT_CNT
	void __iomem *mmio = lp->mmio;
	unsigned int reg_val;

	reg_val = readl(mmio + PHY_ACCESS);
	while (reg_val & PHY_CMD_ACTIVE)
		reg_val = readl( mmio + PHY_ACCESS );

	writel( PHY_WR_CMD | ((phy_id & 0x1f) << 21) |
			   ((reg & 0x1f) << 16)|val, mmio + PHY_ACCESS);

	do{
		reg_val = readl(mmio + PHY_ACCESS);
		udelay(30);  /* It takes 30 us to read/write the data */
	} while (--repeat && (reg_val & PHY_CMD_ACTIVE));
	
	if(reg_val & PHY_RD_ERR)
		goto err_phy_write;
	
	return 0;

err_phy_write:	
	return -EINVAL;
	
}
/* 
This is the mii register read function provided to the mii interface.
*/ 
static int amd8111e_mdio_read(struct net_device * dev, int phy_id, int reg_num)
{
	struct amd8111e_priv* lp = netdev_priv(dev);
	unsigned int reg_val;

	amd8111e_read_phy(lp,phy_id,reg_num,&reg_val);
	return reg_val;
	
}

/* 
This is the mii register write function provided to the mii interface.
*/ 
static void amd8111e_mdio_write(struct net_device * dev, int phy_id, int reg_num, int val)
{
	struct amd8111e_priv* lp = netdev_priv(dev);

	amd8111e_write_phy(lp, phy_id, reg_num, val);
}

/*
This function will set PHY speed. During initialization sets the original speed to 100 full.
*/
static void amd8111e_set_ext_phy(struct net_device *dev)
{
	struct amd8111e_priv *lp = netdev_priv(dev);
	u32 bmcr,advert,tmp;
	
	/* Determine mii register values to set the speed */
	advert = amd8111e_mdio_read(dev, lp->ext_phy_addr, MII_ADVERTISE);
	tmp = advert & ~(ADVERTISE_ALL | ADVERTISE_100BASE4);
	switch (lp->ext_phy_option){

		default:
		case SPEED_AUTONEG: /* advertise all values */
			tmp |= ( ADVERTISE_10HALF|ADVERTISE_10FULL|
				ADVERTISE_100HALF|ADVERTISE_100FULL) ;
			break;
		case SPEED10_HALF:
			tmp |= ADVERTISE_10HALF;
			break;
		case SPEED10_FULL:
			tmp |= ADVERTISE_10FULL;
			break;
		case SPEED100_HALF: 
			tmp |= ADVERTISE_100HALF;
			break;
		case SPEED100_FULL:
			tmp |= ADVERTISE_100FULL;
			break;
	}

	if(advert != tmp)
		amd8111e_mdio_write(dev, lp->ext_phy_addr, MII_ADVERTISE, tmp);
	/* Restart auto negotiation */
	bmcr = amd8111e_mdio_read(dev, lp->ext_phy_addr, MII_BMCR);
	bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
	amd8111e_mdio_write(dev, lp->ext_phy_addr, MII_BMCR, bmcr);

}

/* 
This function will unmap skb->data space and will free 
all transmit and receive skbuffs.
*/
static int amd8111e_free_skbs(struct net_device *dev)
{
	struct amd8111e_priv *lp = netdev_priv(dev);
	struct sk_buff* rx_skbuff;
	int i;

	/* Freeing transmit skbs */
	for(i = 0; i < NUM_TX_BUFFERS; i++){
		if(lp->tx_skbuff[i]){
			pci_unmap_single(lp->pci_dev,lp->tx_dma_addr[i],					lp->tx_skbuff[i]->len,PCI_DMA_TODEVICE);
			dev_kfree_skb (lp->tx_skbuff[i]);
			lp->tx_skbuff[i] = NULL;
			lp->tx_dma_addr[i] = 0;
		}
	}
	/* Freeing previously allocated receive buffers */
	for (i = 0; i < NUM_RX_BUFFERS; i++){
		rx_skbuff = lp->rx_skbuff[i];
		if(rx_skbuff != NULL){
			pci_unmap_single(lp->pci_dev,lp->rx_dma_addr[i],
				  lp->rx_buff_len - 2,PCI_DMA_FROMDEVICE);
			dev_kfree_skb(lp->rx_skbuff[i]);
			lp->rx_skbuff[i] = NULL;
			lp->rx_dma_addr[i] = 0;
		}
	}
	
	return 0;
}

/*
This will set the receive buffer length corresponding to the mtu size of networkinterface.
*/
static inline void amd8111e_set_rx_buff_len(struct net_device* dev)
{
	struct amd8111e_priv* lp = netdev_priv(dev);
	unsigned int mtu = dev->mtu;
	
	if (mtu > ETH_DATA_LEN){
		/* MTU + ethernet header + FCS
		+ optional VLAN tag + skb reserve space 2 */

		lp->rx_buff_len = mtu + ETH_HLEN + 10;
		lp->options |= OPTION_JUMBO_ENABLE;
	} else{
		lp->rx_buff_len = PKT_BUFF_SZ;
		lp->options &= ~OPTION_JUMBO_ENABLE;
	}
}

/* 
This function will free all the previously allocated buffers, determine new receive buffer length  and will allocate new receive buffers. This function also allocates and initializes both the transmitter and receive hardware descriptors.
 */
static int amd8111e_init_ring(struct net_device *dev)
{
	struct amd8111e_priv *lp = netdev_priv(dev);
	int i;

	lp->rx_idx = lp->tx_idx = 0;
	lp->tx_complete_idx = 0;
	lp->tx_ring_idx = 0;
	

	if(lp->opened)
		/* Free previously allocated transmit and receive skbs */
		amd8111e_free_skbs(dev);	

	else{
		 /* allocate the tx and rx descriptors */
	     	if((lp->tx_ring = pci_alloc_consistent(lp->pci_dev, 
			sizeof(struct amd8111e_tx_dr)*NUM_TX_RING_DR,
			&lp->tx_ring_dma_addr)) == NULL)
		
			goto err_no_mem;
	
	     	if((lp->rx_ring = pci_alloc_consistent(lp->pci_dev, 
			sizeof(struct amd8111e_rx_dr)*NUM_RX_RING_DR,
			&lp->rx_ring_dma_addr)) == NULL)
		
			goto err_free_tx_ring;

	}
	/* Set new receive buff size */
	amd8111e_set_rx_buff_len(dev);

	/* Allocating receive  skbs */
	for (i = 0; i < NUM_RX_BUFFERS; i++) {

		if (!(lp->rx_skbuff[i] = dev_alloc_skb(lp->rx_buff_len))) {
				/* Release previos allocated skbs */
				for(--i; i >= 0 ;i--)
					dev_kfree_skb(lp->rx_skbuff[i]);
				goto err_free_rx_ring;
		}
		skb_reserve(lp->rx_skbuff[i],2);
	}
        /* Initilaizing receive descriptors */
	for (i = 0; i < NUM_RX_BUFFERS; i++) {
		lp->rx_dma_addr[i] = pci_map_single(lp->pci_dev, 
			lp->rx_skbuff[i]->data,lp->rx_buff_len-2, PCI_DMA_FROMDEVICE);

		lp->rx_ring[i].buff_phy_addr = cpu_to_le32(lp->rx_dma_addr[i]);
		lp->rx_ring[i].buff_count = cpu_to_le16(lp->rx_buff_len-2);
		wmb();
		lp->rx_ring[i].rx_flags = cpu_to_le16(OWN_BIT);
	}

	/* Initializing transmit descriptors */
	for (i = 0; i < NUM_TX_RING_DR; i++) {
		lp->tx_ring[i].buff_phy_addr = 0;
		lp->tx_ring[i].tx_flags = 0;
		lp->tx_ring[i].buff_count = 0;
	}

	return 0;

err_free_rx_ring:
	
	pci_free_consistent(lp->pci_dev, 
		sizeof(struct amd8111e_rx_dr)*NUM_RX_RING_DR,lp->rx_ring,
		lp->rx_ring_dma_addr);

err_free_tx_ring:
	
	pci_free_consistent(lp->pci_dev,
		 sizeof(struct amd8111e_tx_dr)*NUM_TX_RING_DR,lp->tx_ring, 
		 lp->tx_ring_dma_addr);

err_no_mem:
	return -ENOMEM;
}
/* This function will set the interrupt coalescing according to the input arguments */
static int amd8111e_set_coalesce(struct net_device * dev, enum coal_mode cmod)
{
	unsigned int timeout;
	unsigned int event_count;

	struct amd8111e_priv *lp = netdev_priv(dev);
	void __iomem *mmio = lp->mmio;
	struct amd8111e_coalesce_conf * coal_conf = &lp->coal_conf;


	switch(cmod)
	{
		case RX_INTR_COAL :
			timeout = coal_conf->rx_timeout;
			event_count = coal_conf->rx_event_count;
			if( timeout > MAX_TIMEOUT || 
					event_count > MAX_EVENT_COUNT ) 
			return -EINVAL;

			timeout = timeout * DELAY_TIMER_CONV; 
			writel(VAL0|STINTEN, mmio+INTEN0);
			writel((u32)DLY_INT_A_R0|( event_count<< 16 )|timeout,
							mmio+DLY_INT_A);
			break;

		case TX_INTR_COAL :
			timeout = coal_conf->tx_timeout;
			event_count = coal_conf->tx_event_count;
			if( timeout > MAX_TIMEOUT || 
					event_count > MAX_EVENT_COUNT ) 
			return -EINVAL;

		   
			timeout = timeout * DELAY_TIMER_CONV; 
			writel(VAL0|STINTEN,mmio+INTEN0);
			writel((u32)DLY_INT_B_T0|( event_count<< 16 )|timeout,
							 mmio+DLY_INT_B);
			break;

		case DISABLE_COAL:
			writel(0,mmio+STVAL);
			writel(STINTEN, mmio+INTEN0);
			writel(0, mmio +DLY_INT_B);
			writel(0, mmio+DLY_INT_A);
			break;
		 case ENABLE_COAL: 
		       /* Start the timer */
			writel((u32)SOFT_TIMER_FREQ, mmio+STVAL); /*  0.5 sec */
			writel(VAL0|STINTEN, mmio+INTEN0);
			break;
		default:
			break;

   }
	return 0;

}

/* 
This function initializes the device registers  and starts the device.  
*/
static int amd8111e_restart(struct net_device *dev)
{
	struct amd8111e_priv *lp = netdev_priv(dev);
	void __iomem *mmio = lp->mmio;
	int i,reg_val;

	/* stop the chip */
	 writel(RUN, mmio + CMD0);

	if(amd8111e_init_ring(dev))
		return -ENOMEM;

	/* enable the port manager and set auto negotiation always */
	writel((u32) VAL1|EN_PMGR, mmio + CMD3 );
	writel((u32)XPHYANE|XPHYRST , mmio + CTRL2); 
	
	amd8111e_set_ext_phy(dev);

	/* set control registers */
	reg_val = readl(mmio + CTRL1);
	reg_val &= ~XMTSP_MASK;
	writel( reg_val| XMTSP_128 | CACHE_ALIGN, mmio + CTRL1 );

	/* enable interrupt */
	writel( APINT5EN | APINT4EN | APINT3EN | APINT2EN | APINT1EN | 
		APINT0EN | MIIPDTINTEN | MCCIINTEN | MCCINTEN | MREINTEN |
		SPNDINTEN | MPINTEN | SINTEN | STINTEN, mmio + INTEN0);

	writel(VAL3 | LCINTEN | VAL1 | TINTEN0 | VAL0 | RINTEN0, mmio + INTEN0);

	/* initialize tx and rx ring base addresses */
	writel((u32)lp->tx_ring_dma_addr,mmio + XMT_RING_BASE_ADDR0);
	writel((u32)lp->rx_ring_dma_addr,mmio+ RCV_RING_BASE_ADDR0);

	writew((u32)NUM_TX_RING_DR, mmio + XMT_RING_LEN0);
	writew((u16)NUM_RX_RING_DR, mmio + RCV_RING_LEN0);
	
	/* set default IPG to 96 */
	writew((u32)DEFAULT_IPG,mmio+IPG);
	writew((u32)(DEFAULT_IPG-IFS1_DELTA), mmio + IFS1); 

	if(lp->options & OPTION_JUMBO_ENABLE){
		writel((u32)VAL2|JUMBO, mmio + CMD3);
		/* Reset REX_UFLO */
		writel( REX_UFLO, mmio + CMD2);
		/* Should not set REX_UFLO for jumbo frames */
		writel( VAL0 | APAD_XMT|REX_RTRY , mmio + CMD2);
	}else{
		writel( VAL0 | APAD_XMT | REX_RTRY|REX_UFLO, mmio + CMD2);
		writel((u32)JUMBO, mmio + CMD3);
	}

#if AMD8111E_VLAN_TAG_USED
	writel((u32) VAL2|VSIZE|VL_TAG_DEL, mmio + CMD3);
#endif
	writel( VAL0 | APAD_XMT | REX_RTRY, mmio + CMD2 );
	
	/* Setting the MAC address to the device */
	for(i = 0; i < ETH_ADDR_LEN; i++)
		writeb( dev->dev_addr[i], mmio + PADR + i ); 

	/* Enable interrupt coalesce */
	if(lp->options & OPTION_INTR_COAL_ENABLE){
		printk(KERN_INFO "%s: Interrupt Coalescing Enabled.\n",
								dev->name);
		amd8111e_set_coalesce(dev,ENABLE_COAL);
	}
	
	/* set RUN bit to start the chip */
	writel(VAL2 | RDMD0, mmio + CMD0);
	writel(VAL0 | INTREN | RUN, mmio + CMD0);
	
	/* To avoid PCI posting bug */
	readl(mmio+CMD0);
	return 0;
}
/* 
This function clears necessary the device registers. 
*/	
static void amd8111e_init_hw_default( struct amd8111e_priv* lp)
{
	unsigned int reg_val;
	unsigned int logic_filter[2] ={0,};
	void __iomem *mmio = lp->mmio;


        /* stop the chip */
	writel(RUN, mmio + CMD0);

	/* AUTOPOLL0 Register *//*TBD default value is 8100 in FPS */
	writew( 0x8100 | lp->ext_phy_addr, mmio + AUTOPOLL0);

	/* Clear RCV_RING_BASE_ADDR */
	writel(0, mmio + RCV_RING_BASE_ADDR0);

	/* Clear XMT_RING_BASE_ADDR */
	writel(0, mmio + XMT_RING_BASE_ADDR0);
	writel(0, mmio + XMT_RING_BASE_ADDR1);
	writel(0, mmio + XMT_RING_BASE_ADDR2);
	writel(0, mmio + XMT_RING_BASE_ADDR3);

	/* Clear CMD0  */
	writel(CMD0_CLEAR,mmio + CMD0);
	
	/* Clear CMD2 */
	writel(CMD2_CLEAR, mmio +CMD2);

	/* Clear CMD7 */
	writel(CMD7_CLEAR , mmio + CMD7);

	/* Clear DLY_INT_A and DLY_INT_B */
	writel(0x0, mmio + DLY_INT_A);
	writel(0x0, mmio + DLY_INT_B);

	/* Clear FLOW_CONTROL */
	writel(0x0, mmio + FLOW_CONTROL);

	/* Clear INT0  write 1 to clear register */
	reg_val = readl(mmio + INT0);
	writel(reg_val, mmio + INT0);

	/* Clear STVAL */
	writel(0x0, mmio + STVAL);

	/* Clear INTEN0 */
	writel( INTEN0_CLEAR, mmio + INTEN0);

	/* Clear LADRF */
	writel(0x0 , mmio + LADRF);

	/* Set SRAM_SIZE & SRAM_BOUNDARY registers  */
	writel( 0x80010,mmio + SRAM_SIZE);

	/* Clear RCV_RING0_LEN */
	writel(0x0, mmio +  RCV_RING_LEN0);

	/* Clear XMT_RING0/1/2/3_LEN */
	writel(0x0, mmio +  XMT_RING_LEN0);
	writel(0x0, mmio +  XMT_RING_LEN1);
	writel(0x0, mmio +  XMT_RING_LEN2);
	writel(0x0, mmio +  XMT_RING_LEN3);

	/* Clear XMT_RING_LIMIT */
	writel(0x0, mmio + XMT_RING_LIMIT);

	/* Clear MIB */
	writew(MIB_CLEAR, mmio + MIB_ADDR);

	/* Clear LARF */
	amd8111e_writeq(*(u64*)logic_filter,mmio+LADRF);

	/* SRAM_SIZE register */
	reg_val = readl(mmio + SRAM_SIZE);
	
	if(lp->options & OPTION_JUMBO_ENABLE)
		writel( VAL2|JUMBO, mmio + CMD3);
#if AMD8111E_VLAN_TAG_USED
	writel(VAL2|VSIZE|VL_TAG_DEL, mmio + CMD3 );
#endif
	/* Set default value to CTRL1 Register */
	writel(CTRL1_DEFAULT, mmio + CTRL1);

	/* To avoid PCI posting bug */
	readl(mmio + CMD2);

}

/* 
This function disables the interrupt and clears all the pending 
interrupts in INT0
 */
static void amd8111e_disable_interrupt(struct amd8111e_priv* lp)
{	
	u32 intr0;

	/* Disable interrupt */
	writel(INTREN, lp->mmio + CMD0);
	
	/* Clear INT0 */
	intr0 = readl(lp->mmio + INT0);
	writel(intr0, lp->mmio + INT0);
	
	/* To avoid PCI posting bug */
	readl(lp->mmio + INT0);

}

/*
This function stops the chip. 
*/
static void amd8111e_stop_chip(struct amd8111e_priv* lp)
{
	writel(RUN, lp->mmio + CMD0);
	
	/* To avoid PCI posting bug */
	readl(lp->mmio + CMD0);
}

/* 
This function frees the  transmiter and receiver descriptor rings.
*/
static void amd8111e_free_ring(struct amd8111e_priv* lp)
{	

	/* Free transmit and receive skbs */
	amd8111e_free_skbs(lp->amd8111e_net_dev);

	/* Free transmit and receive descriptor rings */
	if(lp->rx_ring){
		pci_free_consistent(lp->pci_dev, 
			sizeof(struct amd8111e_rx_dr)*NUM_RX_RING_DR,
			lp->rx_ring, lp->rx_ring_dma_addr);
		lp->rx_ring = NULL;
	}
	
	if(lp->tx_ring){
		pci_free_consistent(lp->pci_dev, 
			sizeof(struct amd8111e_tx_dr)*NUM_TX_RING_DR,
			lp->tx_ring, lp->tx_ring_dma_addr);

		lp->tx_ring = NULL;
	}

}
#if AMD8111E_VLAN_TAG_USED	
/* 
This is the receive indication function for packets with vlan tag.
*/	
static int amd8111e_vlan_rx(struct amd8111e_priv *lp, struct sk_buff *skb, u16 vlan_tag)
{
#ifdef CONFIG_AMD8111E_NAPI
	return vlan_hwaccel_receive_skb(skb, lp->vlgrp,vlan_tag);
#else
	return vlan_hwaccel_rx(skb, lp->vlgrp, vlan_tag);
#endif /* CONFIG_AMD8111E_NAPI */
}
#endif

/*
This function will free all the transmit skbs that are actually transmitted by the device. It will check the ownership of the skb before freeing the skb. 
*/
static int amd8111e_tx(struct net_device *dev)
{
	struct amd8111e_priv* lp = netdev_priv(dev);
	int tx_index = lp->tx_complete_idx & TX_RING_DR_MOD_MASK;
	int status;
	/* Complete all the transmit packet */
	while (lp->tx_complete_idx != lp->tx_idx){
		tx_index =  lp->tx_complete_idx & TX_RING_DR_MOD_MASK;
		status = le16_to_cpu(lp->tx_ring[tx_index].tx_flags);

		if(status & OWN_BIT)
			break;	/* It still hasn't been Txed */

		lp->tx_ring[tx_index].buff_phy_addr = 0;

		/* We must free the original skb */
		if (lp->tx_skbuff[tx_index]) {
			pci_unmap_single(lp->pci_dev, lp->tx_dma_addr[tx_index],
				  	lp->tx_skbuff[tx_index]->len,
					PCI_DMA_TODEVICE);
			dev_kfree_skb_irq (lp->tx_skbuff[tx_index]);
			lp->tx_skbuff[tx_index] = NULL;
			lp->tx_dma_addr[tx_index] = 0;
		}
		lp->tx_complete_idx++;
		/*COAL update tx coalescing parameters */
		lp->coal_conf.tx_packets++;
		lp->coal_conf.tx_bytes += lp->tx_ring[tx_index].buff_count;	

		if (netif_queue_stopped(dev) &&
			lp->tx_complete_idx > lp->tx_idx - NUM_TX_BUFFERS +2){
			/* The ring is no longer full, clear tbusy. */
			/* lp->tx_full = 0; */
			netif_wake_queue (dev);
		}
	}
	return 0;
}

#ifdef CONFIG_AMD8111E_NAPI
/* This function handles the driver receive operation in polling mode */
static int amd8111e_rx_poll(struct net_device *dev, int * budget)
{
	struct amd8111e_priv *lp = netdev_priv(dev);
	int rx_index = lp->rx_idx & RX_RING_DR_MOD_MASK;
	void __iomem *mmio = lp->mmio;
	struct sk_buff *skb,*new_skb;
	int min_pkt_len, status;
	unsigned int intr0;
	int num_rx_pkt = 0;
	/*int max_rx_pkt = NUM_RX_BUFFERS;*/
	short pkt_len;
#if AMD8111E_VLAN_TAG_USED		
	short vtag;
#endif
	int rx_pkt_limit = dev->quota;
	
	do{   
		/* process receive packets until we use the quota*/
		/* If we own the next entry, it's a new packet. Send it up. */
		while(1) {
			status = le16_to_cpu(lp->rx_ring[rx_index].rx_flags);
			if (status & OWN_BIT)
				break;

			/* 
			 * There is a tricky error noted by John Murphy,
			 * <murf@perftech.com> to Russ Nelson: Even with
			 * full-sized * buffers it's possible for a  
			 * jabber packet to use two buffers, with only 
			 * the last correctly noting the error.
			 */

			if(status & ERR_BIT) {
				/* reseting flags */
				lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
				goto err_next_pkt;
			}
			/* check for STP and ENP */
			if(!((status & STP_BIT) && (status & ENP_BIT))){
				/* reseting flags */
				lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
				goto err_next_pkt;
			}
			pkt_len = le16_to_cpu(lp->rx_ring[rx_index].msg_count) - 4;

#if AMD8111E_VLAN_TAG_USED		
			vtag = status & TT_MASK;
			/*MAC will strip vlan tag*/ 
			if(lp->vlgrp != NULL && vtag !=0)
				min_pkt_len =MIN_PKT_LEN - 4;
			else
#endif
				min_pkt_len =MIN_PKT_LEN;

			if (pkt_len < min_pkt_len) {
				lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
				lp->drv_rx_errors++;
				goto err_next_pkt;
			}
			if(--rx_pkt_limit < 0)
				goto rx_not_empty;
			if(!(new_skb = dev_alloc_skb(lp->rx_buff_len))){
				/* if allocation fail, 
				   ignore that pkt and go to next one */
				lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
				lp->drv_rx_errors++;
				goto err_next_pkt;
			}
		
			skb_reserve(new_skb, 2);
			skb = lp->rx_skbuff[rx_index];
			pci_unmap_single(lp->pci_dev,lp->rx_dma_addr[rx_index],
					 lp->rx_buff_len-2, PCI_DMA_FROMDEVICE);
			skb_put(skb, pkt_len);
			skb->dev = dev;
			lp->rx_skbuff[rx_index] = new_skb;
			new_skb->dev = dev;
			lp->rx_dma_addr[rx_index] = pci_map_single(lp->pci_dev,
								   new_skb->data,
								   lp->rx_buff_len-2,
								   PCI_DMA_FROMDEVICE);
	
			skb->protocol = eth_type_trans(skb, dev);

#if AMD8111E_VLAN_TAG_USED		
			if(lp->vlgrp != NULL && (vtag == TT_VLAN_TAGGED)){
				amd8111e_vlan_rx(lp, skb,
					 le16_to_cpu(lp->rx_ring[rx_index].tag_ctrl_info));
			} else
#endif
				netif_receive_skb(skb);
			/*COAL update rx coalescing parameters*/
			lp->coal_conf.rx_packets++;
			lp->coal_conf.rx_bytes += pkt_len;	
			num_rx_pkt++;
			dev->last_rx = jiffies;
	
		err_next_pkt:	
			lp->rx_ring[rx_index].buff_phy_addr
				= cpu_to_le32(lp->rx_dma_addr[rx_index]);
			lp->rx_ring[rx_index].buff_count = 
				cpu_to_le16(lp->rx_buff_len-2);
			wmb();
			lp->rx_ring[rx_index].rx_flags |= cpu_to_le16(OWN_BIT);
			rx_index = (++lp->rx_idx) & RX_RING_DR_MOD_MASK;
		}
		/* Check the interrupt status register for more packets in the 
		   mean time. Process them since we have not used up our quota.*/

		intr0 = readl(mmio + INT0);
		/*Ack receive packets */
		writel(intr0 & RINT0,mmio + INT0);

	} while(intr0 & RINT0);

	/* Receive descriptor is empty now */
	dev->quota -= num_rx_pkt;
	*budget -= num_rx_pkt;
	netif_rx_complete(dev);
	/* enable receive interrupt */
	writel(VAL0|RINTEN0, mmio + INTEN0);
	writel(VAL2 | RDMD0, mmio + CMD0);
	return 0;
rx_not_empty:
	/* Do not call a netif_rx_complete */
	dev->quota -= num_rx_pkt;	
	*budget -= num_rx_pkt;
	return 1;

	
}

#else
/* 
This function will check the ownership of receive buffers and descriptors. It will indicate to kernel up to half the number of maximum receive buffers in the descriptor ring, in a single receive interrupt. It will also replenish the descriptors with new skbs.
*/
static int amd8111e_rx(struct net_device *dev)
{
	struct amd8111e_priv *lp = netdev_priv(dev);
	struct sk_buff *skb,*new_skb;
	int rx_index = lp->rx_idx & RX_RING_DR_MOD_MASK;
	int min_pkt_len, status;
	int num_rx_pkt = 0;
	int max_rx_pkt = NUM_RX_BUFFERS;
	short pkt_len;
#if AMD8111E_VLAN_TAG_USED		
	short vtag;
#endif
	
	/* If we own the next entry, it's a new packet. Send it up. */
	while(++num_rx_pkt <= max_rx_pkt){
		status = le16_to_cpu(lp->rx_ring[rx_index].rx_flags);
		if(status & OWN_BIT)
			return 0;
	       
		/* check if err summary bit is set */ 
		if(status & ERR_BIT){
			/* 
			 * There is a tricky error noted by John Murphy,
			 * <murf@perftech.com> to Russ Nelson: Even with full-sized
			 * buffers it's possible for a jabber packet to use two
			 * buffers, with only the last correctly noting the error.			 */
			/* reseting flags */
			lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
			goto err_next_pkt;
		}
		/* check for STP and ENP */
		if(!((status & STP_BIT) && (status & ENP_BIT))){
			/* reseting flags */
			lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
			goto err_next_pkt;
		}
		pkt_len = le16_to_cpu(lp->rx_ring[rx_index].msg_count) - 4;

#if AMD8111E_VLAN_TAG_USED		
		vtag = status & TT_MASK;
		/*MAC will strip vlan tag*/ 
		if(lp->vlgrp != NULL && vtag !=0)
			min_pkt_len =MIN_PKT_LEN - 4;
		else
#endif
			min_pkt_len =MIN_PKT_LEN;

		if (pkt_len < min_pkt_len) {
			lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
			lp->drv_rx_errors++;
			goto err_next_pkt;
		}
		if(!(new_skb = dev_alloc_skb(lp->rx_buff_len))){
			/* if allocation fail, 
				ignore that pkt and go to next one */
			lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
			lp->drv_rx_errors++;
			goto err_next_pkt;
		}
		
		skb_reserve(new_skb, 2);
		skb = lp->rx_skbuff[rx_index];
		pci_unmap_single(lp->pci_dev,lp->rx_dma_addr[rx_index],
			lp->rx_buff_len-2, PCI_DMA_FROMDEVICE);
		skb_put(skb, pkt_len);
		skb->dev = dev;
		lp->rx_skbuff[rx_index] = new_skb;
		new_skb->dev = dev;
		lp->rx_dma_addr[rx_index] = pci_map_single(lp->pci_dev,
			new_skb->data, lp->rx_buff_len-2,PCI_DMA_FROMDEVICE);
	
		skb->protocol = eth_type_trans(skb, dev);

#if AMD8111E_VLAN_TAG_USED				
		if(lp->vlgrp != NULL && (vtag == TT_VLAN_TAGGED)){
			amd8111e_vlan_rx(lp, skb,
				 le16_to_cpu(lp->rx_ring[rx_index].tag_ctrl_info));
		} else
#endif
			
			netif_rx (skb);
			/*COAL update rx coalescing parameters*/
			lp->coal_conf.rx_packets++;
			lp->coal_conf.rx_bytes += pkt_len;	

			dev->last_rx = jiffies;
	
err_next_pkt:
		lp->rx_ring[rx_index].buff_phy_addr
			 = cpu_to_le32(lp->rx_dma_addr[rx_index]);
		lp->rx_ring[rx_index].buff_count = 
				cpu_to_le16(lp->rx_buff_len-2);
		wmb();
		lp->rx_ring[rx_index].rx_flags |= cpu_to_le16(OWN_BIT);
		rx_index = (++lp->rx_idx) & RX_RING_DR_MOD_MASK;
	}

	return 0;
}
#endif /* CONFIG_AMD8111E_NAPI */
/* 
This function will indicate the link status to the kernel.
*/
static int amd8111e_link_change(struct net_device* dev)
{	
	struct amd8111e_priv *lp = netdev_priv(dev);
	int status0,speed;

	/* read the link change */
     	status0 = readl(lp->mmio + STAT0);
	
	if(status0 & LINK_STATS){
		if(status0 & AUTONEG_COMPLETE)
			lp->link_config.autoneg = AUTONEG_ENABLE;
		else 
			lp->link_config.autoneg = AUTONEG_DISABLE;

		if(status0 & FULL_DPLX)
			lp->link_config.duplex = DUPLEX_FULL;
		else 
			lp->link_config.duplex = DUPLEX_HALF;
		speed = (status0 & SPEED_MASK) >> 7;
		if(speed == PHY_SPEED_10)
			lp->link_config.speed = SPEED_10;
		else if(speed == PHY_SPEED_100)
			lp->link_config.speed = SPEED_100;

		printk(KERN_INFO "%s: Link is Up. Speed is %s Mbps %s Duplex\n",			dev->name,
		       (lp->link_config.speed == SPEED_100) ? "100": "10", 
		       (lp->link_config.duplex == DUPLEX_FULL)? "Full": "Half"); 
		netif_carrier_on(dev);
	}
	else{	
		lp->link_config.speed = SPEED_INVALID;
		lp->link_config.duplex = DUPLEX_INVALID;
		lp->link_config.autoneg = AUTONEG_INVALID;
		printk(KERN_INFO "%s: Link is Down.\n",dev->name);
		netif_carrier_off(dev);
	}