fs_enet-main.c

linux-2.6.15.6

/*
 * Combined Ethernet driver for Motorola MPC8xx and MPC82xx.
 *
 * Copyright (c) 2003 Intracom S.A. 
 *  by Pantelis Antoniou <[e-mail]>
 * 
 * 2005 (c) MontaVista Software, Inc. 
 * Vitaly Bordug <[e-mail]>
 *
 * Heavily based on original FEC driver by Dan Malek <[e-mail]>
 * and modifications by Joakim Tjernlund <[e-mail]>
 *
 * This file is licensed under the terms of the GNU General Public License 
 * version 2. This program is licensed "as is" without any warranty of any 
 * kind, whether express or implied.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/bitops.h>
#include <linux/fs.h>
#include <linux/platform_device.h>

#include <linux/vmalloc.h>
#include <asm/pgtable.h>

#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/uaccess.h>

#include "fs_enet.h"

/*************************************************/

static char version[] __devinitdata =
    DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")" "\n";

MODULE_AUTHOR("Pantelis Antoniou <[e-mail]>");
MODULE_DESCRIPTION("Freescale Ethernet Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_MODULE_VERSION);

MODULE_PARM(fs_enet_debug, "i");
MODULE_PARM_DESC(fs_enet_debug,
		 "Freescale bitmapped debugging message enable value");

int fs_enet_debug = -1;		/* -1 == use FS_ENET_DEF_MSG_ENABLE as value */

static void fs_set_multicast_list(struct net_device *dev)
{
	struct fs_enet_private *fep = netdev_priv(dev);

	(*fep->ops->set_multicast_list)(dev);
}

/* NAPI receive function */
static int fs_enet_rx_napi(struct net_device *dev, int *budget)
{
	struct fs_enet_private *fep = netdev_priv(dev);
	const struct fs_platform_info *fpi = fep->fpi;
	cbd_t *bdp;
	struct sk_buff *skb, *skbn, *skbt;
	int received = 0;
	u16 pkt_len, sc;
	int curidx;
	int rx_work_limit = 0;	/* pacify gcc */

	rx_work_limit = min(dev->quota, *budget);

	if (!netif_running(dev))
		return 0;

	/*
	 * First, grab all of the stats for the incoming packet.
	 * These get messed up if we get called due to a busy condition.
	 */
	bdp = fep->cur_rx;

	/* clear RX status bits for napi*/
	(*fep->ops->napi_clear_rx_event)(dev);

	while (((sc = CBDR_SC(bdp)) & BD_ENET_RX_EMPTY) == 0) {

		curidx = bdp - fep->rx_bd_base;

		/*
		 * Since we have allocated space to hold a complete frame,
		 * the last indicator should be set.
		 */
		if ((sc & BD_ENET_RX_LAST) == 0)
			printk(KERN_WARNING DRV_MODULE_NAME
			       ": %s rcv is not +last\n",
			       dev->name);

		/*
		 * Check for errors. 
		 */
		if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_CL |
			  BD_ENET_RX_NO | BD_ENET_RX_CR | BD_ENET_RX_OV)) {
			fep->stats.rx_errors++;
			/* Frame too long or too short. */
			if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
				fep->stats.rx_length_errors++;
			/* Frame alignment */
			if (sc & (BD_ENET_RX_NO | BD_ENET_RX_CL))
				fep->stats.rx_frame_errors++;
			/* CRC Error */
			if (sc & BD_ENET_RX_CR)
				fep->stats.rx_crc_errors++;
			/* FIFO overrun */
			if (sc & BD_ENET_RX_OV)
				fep->stats.rx_crc_errors++;

			skb = fep->rx_skbuff[curidx];

			dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
				DMA_FROM_DEVICE);

			skbn = skb;

		} else {

			/* napi, got packet but no quota */
			if (--rx_work_limit < 0)
				break;

			skb = fep->rx_skbuff[curidx];

			dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
				DMA_FROM_DEVICE);

			/*
			 * Process the incoming frame.
			 */
			fep->stats.rx_packets++;
			pkt_len = CBDR_DATLEN(bdp) - 4;	/* remove CRC */
			fep->stats.rx_bytes += pkt_len + 4;

			if (pkt_len <= fpi->rx_copybreak) {
				/* +2 to make IP header L1 cache aligned */
				skbn = dev_alloc_skb(pkt_len + 2);
				if (skbn != NULL) {
					skb_reserve(skbn, 2);	/* align IP header */
					memcpy(skbn->data, skb->data, pkt_len);
					/* swap */
					skbt = skb;
					skb = skbn;
					skbn = skbt;
				}
			} else
				skbn = dev_alloc_skb(ENET_RX_FRSIZE);

			if (skbn != NULL) {
				skb->dev = dev;
				skb_put(skb, pkt_len);	/* Make room */
				skb->protocol = eth_type_trans(skb, dev);
				received++;
				netif_receive_skb(skb);
			} else {
				printk(KERN_WARNING DRV_MODULE_NAME
				       ": %s Memory squeeze, dropping packet.\n",
				       dev->name);
				fep->stats.rx_dropped++;
				skbn = skb;
			}
		}

		fep->rx_skbuff[curidx] = skbn;
		CBDW_BUFADDR(bdp, dma_map_single(fep->dev, skbn->data,
			     L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
			     DMA_FROM_DEVICE));
		CBDW_DATLEN(bdp, 0);
		CBDW_SC(bdp, (sc & ~BD_ENET_RX_STATS) | BD_ENET_RX_EMPTY);

		/*
		 * Update BD pointer to next entry. 
		 */
		if ((sc & BD_ENET_RX_WRAP) == 0)
			bdp++;
		else
			bdp = fep->rx_bd_base;

		(*fep->ops->rx_bd_done)(dev);
	}

	fep->cur_rx = bdp;

	dev->quota -= received;
	*budget -= received;

	if (rx_work_limit < 0)
		return 1;	/* not done */

	/* done */
	netif_rx_complete(dev);

	(*fep->ops->napi_enable_rx)(dev);

	return 0;
}

/* non NAPI receive function */
static int fs_enet_rx_non_napi(struct net_device *dev)
{
	struct fs_enet_private *fep = netdev_priv(dev);
	const struct fs_platform_info *fpi = fep->fpi;
	cbd_t *bdp;
	struct sk_buff *skb, *skbn, *skbt;
	int received = 0;
	u16 pkt_len, sc;
	int curidx;
	/*
	 * First, grab all of the stats for the incoming packet.
	 * These get messed up if we get called due to a busy condition.
	 */
	bdp = fep->cur_rx;

	while (((sc = CBDR_SC(bdp)) & BD_ENET_RX_EMPTY) == 0) {

		curidx = bdp - fep->rx_bd_base;

		/*
		 * Since we have allocated space to hold a complete frame,
		 * the last indicator should be set.
		 */
		if ((sc & BD_ENET_RX_LAST) == 0)
			printk(KERN_WARNING DRV_MODULE_NAME
			       ": %s rcv is not +last\n",
			       dev->name);

		/*
		 * Check for errors. 
		 */
		if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_CL |
			  BD_ENET_RX_NO | BD_ENET_RX_CR | BD_ENET_RX_OV)) {
			fep->stats.rx_errors++;
			/* Frame too long or too short. */
			if (sc & (BD_ENET_RX_LG | BD_ENET_RX_SH))
				fep->stats.rx_length_errors++;
			/* Frame alignment */
			if (sc & (BD_ENET_RX_NO | BD_ENET_RX_CL))
				fep->stats.rx_frame_errors++;
			/* CRC Error */
			if (sc & BD_ENET_RX_CR)
				fep->stats.rx_crc_errors++;
			/* FIFO overrun */
			if (sc & BD_ENET_RX_OV)
				fep->stats.rx_crc_errors++;

			skb = fep->rx_skbuff[curidx];

			dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
				DMA_FROM_DEVICE);

			skbn = skb;

		} else {

			skb = fep->rx_skbuff[curidx];

			dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
				DMA_FROM_DEVICE);

			/*
			 * Process the incoming frame.
			 */
			fep->stats.rx_packets++;
			pkt_len = CBDR_DATLEN(bdp) - 4;	/* remove CRC */
			fep->stats.rx_bytes += pkt_len + 4;

			if (pkt_len <= fpi->rx_copybreak) {
				/* +2 to make IP header L1 cache aligned */
				skbn = dev_alloc_skb(pkt_len + 2);
				if (skbn != NULL) {
					skb_reserve(skbn, 2);	/* align IP header */
					memcpy(skbn->data, skb->data, pkt_len);
					/* swap */
					skbt = skb;
					skb = skbn;
					skbn = skbt;
				}
			} else
				skbn = dev_alloc_skb(ENET_RX_FRSIZE);

			if (skbn != NULL) {
				skb->dev = dev;
				skb_put(skb, pkt_len);	/* Make room */
				skb->protocol = eth_type_trans(skb, dev);
				received++;
				netif_rx(skb);
			} else {
				printk(KERN_WARNING DRV_MODULE_NAME
				       ": %s Memory squeeze, dropping packet.\n",
				       dev->name);
				fep->stats.rx_dropped++;
				skbn = skb;
			}
		}

		fep->rx_skbuff[curidx] = skbn;
		CBDW_BUFADDR(bdp, dma_map_single(fep->dev, skbn->data,
			     L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
			     DMA_FROM_DEVICE));
		CBDW_DATLEN(bdp, 0);
		CBDW_SC(bdp, (sc & ~BD_ENET_RX_STATS) | BD_ENET_RX_EMPTY);

		/*
		 * Update BD pointer to next entry. 
		 */
		if ((sc & BD_ENET_RX_WRAP) == 0)
			bdp++;
		else
			bdp = fep->rx_bd_base;

		(*fep->ops->rx_bd_done)(dev);
	}

	fep->cur_rx = bdp;

	return 0;
}

static void fs_enet_tx(struct net_device *dev)
{
	struct fs_enet_private *fep = netdev_priv(dev);
	cbd_t *bdp;
	struct sk_buff *skb;
	int dirtyidx, do_wake, do_restart;
	u16 sc;

	spin_lock(&fep->lock);
	bdp = fep->dirty_tx;

	do_wake = do_restart = 0;
	while (((sc = CBDR_SC(bdp)) & BD_ENET_TX_READY) == 0) {

		dirtyidx = bdp - fep->tx_bd_base;

		if (fep->tx_free == fep->tx_ring)
			break;

		skb = fep->tx_skbuff[dirtyidx];

		/*
		 * Check for errors. 
		 */
		if (sc & (BD_ENET_TX_HB | BD_ENET_TX_LC |
			  BD_ENET_TX_RL | BD_ENET_TX_UN | BD_ENET_TX_CSL)) {

			if (sc & BD_ENET_TX_HB)	/* No heartbeat */
				fep->stats.tx_heartbeat_errors++;
			if (sc & BD_ENET_TX_LC)	/* Late collision */
				fep->stats.tx_window_errors++;
			if (sc & BD_ENET_TX_RL)	/* Retrans limit */
				fep->stats.tx_aborted_errors++;
			if (sc & BD_ENET_TX_UN)	/* Underrun */
				fep->stats.tx_fifo_errors++;
			if (sc & BD_ENET_TX_CSL)	/* Carrier lost */
				fep->stats.tx_carrier_errors++;

			if (sc & (BD_ENET_TX_LC | BD_ENET_TX_RL | BD_ENET_TX_UN)) {
				fep->stats.tx_errors++;
				do_restart = 1;
			}
		} else
			fep->stats.tx_packets++;

		if (sc & BD_ENET_TX_READY)
			printk(KERN_WARNING DRV_MODULE_NAME
			       ": %s HEY! Enet xmit interrupt and TX_READY.\n",
			       dev->name);

		/*
		 * Deferred means some collisions occurred during transmit,
		 * but we eventually sent the packet OK.
		 */
		if (sc & BD_ENET_TX_DEF)
			fep->stats.collisions++;

		/* unmap */
		dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
				skb->len, DMA_TO_DEVICE);

		/*
		 * Free the sk buffer associated with this last transmit. 
		 */
		dev_kfree_skb_irq(skb);
		fep->tx_skbuff[dirtyidx] = NULL;

		/*
		 * Update pointer to next buffer descriptor to be transmitted. 
		 */
		if ((sc & BD_ENET_TX_WRAP) == 0)
			bdp++;
		else
			bdp = fep->tx_bd_base;

		/*
		 * Since we have freed up a buffer, the ring is no longer
		 * full.
		 */
		if (!fep->tx_free++)
			do_wake = 1;
	}

	fep->dirty_tx = bdp;

	if (do_restart)
		(*fep->ops->tx_restart)(dev);

	spin_unlock(&fep->lock);

	if (do_wake)
		netif_wake_queue(dev);
}

/*
 * The interrupt handler.
 * This is called from the MPC core interrupt.
 */
static irqreturn_t
fs_enet_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = dev_id;
	struct fs_enet_private *fep;
	const struct fs_platform_info *fpi;
	u32 int_events;
	u32 int_clr_events;
	int nr, napi_ok;
	int handled;

	fep = netdev_priv(dev);
	fpi = fep->fpi;

	nr = 0;
	while ((int_events = (*fep->ops->get_int_events)(dev)) != 0) {

		nr++;

		int_clr_events = int_events;
		if (fpi->use_napi)
			int_clr_events &= ~fep->ev_napi_rx;

		(*fep->ops->clear_int_events)(dev, int_clr_events);

		if (int_events & fep->ev_err)
			(*fep->ops->ev_error)(dev, int_events);

		if (int_events & fep->ev_rx) {
			if (!fpi->use_napi)
				fs_enet_rx_non_napi(dev);
			else {
				napi_ok = netif_rx_schedule_prep(dev);

				(*fep->ops->napi_disable_rx)(dev);
				(*fep->ops->clear_int_events)(dev, fep->ev_napi_rx);

				/* NOTE: it is possible for FCCs in NAPI mode    */
				/* to submit a spurious interrupt while in poll  */
				if (napi_ok)
					__netif_rx_schedule(dev);
			}
		}

		if (int_events & fep->ev_tx)
			fs_enet_tx(dev);
	}

	handled = nr > 0;
	return IRQ_RETVAL(handled);
}

void fs_init_bds(struct net_device *dev)
{
	struct fs_enet_private *fep = netdev_priv(dev);
	cbd_t *bdp;
	struct sk_buff *skb;
	int i;

	fs_cleanup_bds(dev);

	fep->dirty_tx = fep->cur_tx = fep->tx_bd_base;
	fep->tx_free = fep->tx_ring;
	fep->cur_rx = fep->rx_bd_base;

	/*
	 * Initialize the receive buffer descriptors. 
	 */
	for (i = 0, bdp = fep->rx_bd_base; i < fep->rx_ring; i++, bdp++) {
		skb = dev_alloc_skb(ENET_RX_FRSIZE);
		if (skb == NULL) {
			printk(KERN_WARNING DRV_MODULE_NAME
			       ": %s Memory squeeze, unable to allocate skb\n",
			       dev->name);
			break;
		}
		fep->rx_skbuff[i] = skb;
		skb->dev = dev;
		CBDW_BUFADDR(bdp,
			dma_map_single(fep->dev, skb->data,
				L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
				DMA_FROM_DEVICE));
		CBDW_DATLEN(bdp, 0);	/* zero */
		CBDW_SC(bdp, BD_ENET_RX_EMPTY |
			((i < fep->rx_ring - 1) ? 0 : BD_SC_WRAP));
	}
	/*
	 * if we failed, fillup remainder 
	 */
	for (; i < fep->rx_ring; i++, bdp++) {
		fep->rx_skbuff[i] = NULL;
		CBDW_SC(bdp, (i < fep->rx_ring - 1) ? 0 : BD_SC_WRAP);
	}

	/*
	 * ...and the same for transmit.  
	 */
	for (i = 0, bdp = fep->tx_bd_base; i < fep->tx_ring; i++, bdp++) {
		fep->tx_skbuff[i] = NULL;
		CBDW_BUFADDR(bdp, 0);
		CBDW_DATLEN(bdp, 0);
		CBDW_SC(bdp, (i < fep->tx_ring - 1) ? 0 : BD_SC_WRAP);
	}
}

void fs_cleanup_bds(struct net_device *dev)
{
	struct fs_enet_private *fep = netdev_priv(dev);
	struct sk_buff *skb;
	cbd_t *bdp;
	int i;

	/*
	 * Reset SKB transmit buffers.  
	 */
	for (i = 0, bdp = fep->tx_bd_base; i < fep->tx_ring; i++, bdp++) {
		if ((skb = fep->tx_skbuff[i]) == NULL)
			continue;

		/* unmap */
		dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
				skb->len, DMA_TO_DEVICE);

		fep->tx_skbuff[i] = NULL;
		dev_kfree_skb(skb);
	}

	/*
	 * Reset SKB receive buffers 
	 */
	for (i = 0, bdp = fep->rx_bd_base; i < fep->rx_ring; i++, bdp++) {
		if ((skb = fep->rx_skbuff[i]) == NULL)
			continue;

		/* unmap */
		dma_unmap_single(fep->dev, CBDR_BUFADDR(bdp),
			L1_CACHE_ALIGN(PKT_MAXBUF_SIZE),
			DMA_FROM_DEVICE);

		fep->rx_skbuff[i] = NULL;

		dev_kfree_skb(skb);
	}
}

/**********************************************************************************/

static int fs_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct fs_enet_private *fep = netdev_priv(dev);
	cbd_t *bdp;
	int curidx;
	u16 sc;
	unsigned long flags;

	spin_lock_irqsave(&fep->tx_lock, flags);

	/*
	 * Fill in a Tx ring entry 
	 */
	bdp = fep->cur_tx;

	if (!fep->tx_free || (CBDR_SC(bdp) & BD_ENET_TX_READY)) {
		netif_stop_queue(dev);
		spin_unlock_irqrestore(&fep->tx_lock, flags);

		/*
		 * Ooops.  All transmit buffers are full.  Bail out.
		 * This should not happen, since the tx queue should be stopped.
		 */
		printk(KERN_WARNING DRV_MODULE_NAME
		       ": %s tx queue full!.\n", dev->name);
		return NETDEV_TX_BUSY;
	}