RT-AC56 3.0.0.4.374.37 core

[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / drivers / net / skfp / skfddi.c

/*
 * File Name:
 *   skfddi.c
 *
 * Copyright Information:
 *   Copyright SysKonnect 1998,1999.
 *
 * 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.
 *
 * The information in this file is provided "AS IS" without warranty.
 *
 * Abstract:
 *   A Linux device driver supporting the SysKonnect FDDI PCI controller
 *   familie.
 *
 * Maintainers:
 *   CG    Christoph Goos (cgoos@syskonnect.de)
 *
 * Contributors:
 *   DM    David S. Miller
 *
 * Address all question to:
 *   linux@syskonnect.de
 *
 * The technical manual for the adapters is available from SysKonnect's
 * web pages: www.syskonnect.com
 * Goto "Support" and search Knowledge Base for "manual".
 *
 * Driver Architecture:
 *   The driver architecture is based on the DEC FDDI driver by
 *   Lawrence V. Stefani and several ethernet drivers.
 *   I also used an existing Windows NT miniport driver.
 *   All hardware dependent fuctions are handled by the SysKonnect
 *   Hardware Module.
 *   The only headerfiles that are directly related to this source
 *   are skfddi.c, h/types.h, h/osdef1st.h, h/targetos.h.
 *   The others belong to the SysKonnect FDDI Hardware Module and
 *   should better not be changed.
 *
 * Modification History:
 *              Date            Name    Description
 *              02-Mar-98       CG      Created.
 *
 *              10-Mar-99       CG      Support for 2.2.x added.
 *              25-Mar-99       CG      Corrected IRQ routing for SMP (APIC)
 *              26-Oct-99       CG      Fixed compilation error on 2.2.13
 *              12-Nov-99       CG      Source code release
 *              22-Nov-99       CG      Included in kernel source.
 *              07-May-00       DM      64 bit fixes, new dma interface
 *              31-Jul-03       DB      Audit copy_*_user in skfp_ioctl
 *                                        Daniele Bellucci <bellucda@tiscali.it>
 *              03-Dec-03       SH      Convert to PCI device model
 *
 * Compilation options (-Dxxx):
 *              DRIVERDEBUG     print lots of messages to log file
 *              DUMPPACKETS     print received/transmitted packets to logfile
 * 
 * Tested cpu architectures:
 *      - i386
 *      - sparc64
 */

/* Version information string - should be updated prior to */
/* each new release!!! */
#define VERSION         "2.07"

static const char * const boot_msg = 
        "SysKonnect FDDI PCI Adapter driver v" VERSION " for\n"
        "  SK-55xx/SK-58xx adapters (SK-NET FDDI-FP/UP/LP)";

/* Include files */

#include <linux/capability.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/fddidevice.h>
#include <linux/skbuff.h>
#include <linux/bitops.h>
#include <linux/gfp.h>

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

#include        "h/types.h"
#undef ADDR                     // undo Linux definition
#include        "h/skfbi.h"
#include        "h/fddi.h"
#include        "h/smc.h"
#include        "h/smtstate.h"


// Define module-wide (static) routines
static int skfp_driver_init(struct net_device *dev);
static int skfp_open(struct net_device *dev);
static int skfp_close(struct net_device *dev);
static irqreturn_t skfp_interrupt(int irq, void *dev_id);
static struct net_device_stats *skfp_ctl_get_stats(struct net_device *dev);
static void skfp_ctl_set_multicast_list(struct net_device *dev);
static void skfp_ctl_set_multicast_list_wo_lock(struct net_device *dev);
static int skfp_ctl_set_mac_address(struct net_device *dev, void *addr);
static int skfp_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
static netdev_tx_t skfp_send_pkt(struct sk_buff *skb,
                                       struct net_device *dev);
static void send_queued_packets(struct s_smc *smc);
static void CheckSourceAddress(unsigned char *frame, unsigned char *hw_addr);
static void ResetAdapter(struct s_smc *smc);


// Functions needed by the hardware module
void *mac_drv_get_space(struct s_smc *smc, u_int size);
void *mac_drv_get_desc_mem(struct s_smc *smc, u_int size);
unsigned long mac_drv_virt2phys(struct s_smc *smc, void *virt);
unsigned long dma_master(struct s_smc *smc, void *virt, int len, int flag);
void dma_complete(struct s_smc *smc, volatile union s_fp_descr *descr,
                  int flag);
void mac_drv_tx_complete(struct s_smc *smc, volatile struct s_smt_fp_txd *txd);
void llc_restart_tx(struct s_smc *smc);
void mac_drv_rx_complete(struct s_smc *smc, volatile struct s_smt_fp_rxd *rxd,
                         int frag_count, int len);
void mac_drv_requeue_rxd(struct s_smc *smc, volatile struct s_smt_fp_rxd *rxd,
                         int frag_count);
void mac_drv_fill_rxd(struct s_smc *smc);
void mac_drv_clear_rxd(struct s_smc *smc, volatile struct s_smt_fp_rxd *rxd,
                       int frag_count);
int mac_drv_rx_init(struct s_smc *smc, int len, int fc, char *look_ahead,
                    int la_len);
void dump_data(unsigned char *Data, int length);

// External functions from the hardware module
extern u_int mac_drv_check_space(void);
extern int mac_drv_init(struct s_smc *smc);
extern void hwm_tx_frag(struct s_smc *smc, char far * virt, u_long phys,
                        int len, int frame_status);
extern int hwm_tx_init(struct s_smc *smc, u_char fc, int frag_count,
                       int frame_len, int frame_status);
extern void fddi_isr(struct s_smc *smc);
extern void hwm_rx_frag(struct s_smc *smc, char far * virt, u_long phys,
                        int len, int frame_status);
extern void mac_drv_rx_mode(struct s_smc *smc, int mode);
extern void mac_drv_clear_rx_queue(struct s_smc *smc);
extern void enable_tx_irq(struct s_smc *smc, u_short queue);

static DEFINE_PCI_DEVICE_TABLE(skfddi_pci_tbl) = {
        { PCI_VENDOR_ID_SK, PCI_DEVICE_ID_SK_FP, PCI_ANY_ID, PCI_ANY_ID, },
        { }                     /* Terminating entry */
};
MODULE_DEVICE_TABLE(pci, skfddi_pci_tbl);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mirko Lindner <mlindner@syskonnect.de>");

// Define module-wide (static) variables

static int num_boards;  /* total number of adapters configured */

static const struct net_device_ops skfp_netdev_ops = {
        .ndo_open               = skfp_open,
        .ndo_stop               = skfp_close,
        .ndo_start_xmit         = skfp_send_pkt,
        .ndo_get_stats          = skfp_ctl_get_stats,
        .ndo_change_mtu         = fddi_change_mtu,
        .ndo_set_multicast_list = skfp_ctl_set_multicast_list,
        .ndo_set_mac_address    = skfp_ctl_set_mac_address,
        .ndo_do_ioctl           = skfp_ioctl,
};

/*
 * =================
 * = skfp_init_one =
 * =================
 *   
 * Overview:
 *   Probes for supported FDDI PCI controllers
 *  
 * Returns:
 *   Condition code
 *       
 * Arguments:
 *   pdev - pointer to PCI device information
 *
 * Functional Description:
 *   This is now called by PCI driver registration process
 *   for each board found.
 *   
 * Return Codes:
 *   0           - This device (fddi0, fddi1, etc) configured successfully
 *   -ENODEV - No devices present, or no SysKonnect FDDI PCI device
 *                         present for this device name
 *
 *
 * Side Effects:
 *   Device structures for FDDI adapters (fddi0, fddi1, etc) are
 *   initialized and the board resources are read and stored in
 *   the device structure.
 */
static int skfp_init_one(struct pci_dev *pdev,
                                const struct pci_device_id *ent)
{
        struct net_device *dev;
        struct s_smc *smc;      /* board pointer */
        void __iomem *mem;
        int err;

        pr_debug(KERN_INFO "entering skfp_init_one\n");

        if (num_boards == 0) 
                printk("%s\n", boot_msg);

        err = pci_enable_device(pdev);
        if (err)
                return err;

        err = pci_request_regions(pdev, "skfddi");
        if (err)
                goto err_out1;

        pci_set_master(pdev);

#ifdef MEM_MAPPED_IO
        if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
                printk(KERN_ERR "skfp: region is not an MMIO resource\n");
                err = -EIO;
                goto err_out2;
        }

        mem = ioremap(pci_resource_start(pdev, 0), 0x4000);
#else
        if (!(pci_resource_flags(pdev, 1) & IO_RESOURCE_IO)) {
                printk(KERN_ERR "skfp: region is not PIO resource\n");
                err = -EIO;
                goto err_out2;
        }

        mem = ioport_map(pci_resource_start(pdev, 1), FP_IO_LEN);
#endif
        if (!mem) {
                printk(KERN_ERR "skfp:  Unable to map register, "
                                "FDDI adapter will be disabled.\n");
                err = -EIO;
                goto err_out2;
        }

        dev = alloc_fddidev(sizeof(struct s_smc));
        if (!dev) {
                printk(KERN_ERR "skfp: Unable to allocate fddi device, "
                                "FDDI adapter will be disabled.\n");
                err = -ENOMEM;
                goto err_out3;
        }

        dev->irq = pdev->irq;
        dev->netdev_ops = &skfp_netdev_ops;

        SET_NETDEV_DEV(dev, &pdev->dev);

        /* Initialize board structure with bus-specific info */
        smc = netdev_priv(dev);
        smc->os.dev = dev;
        smc->os.bus_type = SK_BUS_TYPE_PCI;
        smc->os.pdev = *pdev;
        smc->os.QueueSkb = MAX_TX_QUEUE_LEN;
        smc->os.MaxFrameSize = MAX_FRAME_SIZE;
        smc->os.dev = dev;
        smc->hw.slot = -1;
        smc->hw.iop = mem;
        smc->os.ResetRequested = FALSE;
        skb_queue_head_init(&smc->os.SendSkbQueue);

        dev->base_addr = (unsigned long)mem;

        err = skfp_driver_init(dev);
        if (err)
                goto err_out4;

        err = register_netdev(dev);
        if (err)
                goto err_out5;

        ++num_boards;
        pci_set_drvdata(pdev, dev);

        if ((pdev->subsystem_device & 0xff00) == 0x5500 ||
            (pdev->subsystem_device & 0xff00) == 0x5800) 
                printk("%s: SysKonnect FDDI PCI adapter"
                       " found (SK-%04X)\n", dev->name, 
                       pdev->subsystem_device);
        else
                printk("%s: FDDI PCI adapter found\n", dev->name);

        return 0;
err_out5:
        if (smc->os.SharedMemAddr) 
                pci_free_consistent(pdev, smc->os.SharedMemSize,
                                    smc->os.SharedMemAddr, 
                                    smc->os.SharedMemDMA);
        pci_free_consistent(pdev, MAX_FRAME_SIZE,
                            smc->os.LocalRxBuffer, smc->os.LocalRxBufferDMA);
err_out4:
        free_netdev(dev);
err_out3:
#ifdef MEM_MAPPED_IO
        iounmap(mem);
#else
        ioport_unmap(mem);
#endif
err_out2:
        pci_release_regions(pdev);
err_out1:
        pci_disable_device(pdev);
        return err;
}

/*
 * Called for each adapter board from pci_unregister_driver
 */
static void __devexit skfp_remove_one(struct pci_dev *pdev)
{
        struct net_device *p = pci_get_drvdata(pdev);
        struct s_smc *lp = netdev_priv(p);

        unregister_netdev(p);

        if (lp->os.SharedMemAddr) {
                pci_free_consistent(&lp->os.pdev,
                                    lp->os.SharedMemSize,
                                    lp->os.SharedMemAddr,
                                    lp->os.SharedMemDMA);
                lp->os.SharedMemAddr = NULL;
        }
        if (lp->os.LocalRxBuffer) {
                pci_free_consistent(&lp->os.pdev,
                                    MAX_FRAME_SIZE,
                                    lp->os.LocalRxBuffer,
                                    lp->os.LocalRxBufferDMA);
                lp->os.LocalRxBuffer = NULL;
        }
#ifdef MEM_MAPPED_IO
        iounmap(lp->hw.iop);
#else
        ioport_unmap(lp->hw.iop);
#endif
        pci_release_regions(pdev);
        free_netdev(p);

        pci_disable_device(pdev);
        pci_set_drvdata(pdev, NULL);
}

/*
 * ====================
 * = skfp_driver_init =
 * ====================
 *   
 * Overview:
 *   Initializes remaining adapter board structure information
 *   and makes sure adapter is in a safe state prior to skfp_open().
 *  
 * Returns:
 *   Condition code
 *       
 * Arguments:
 *   dev - pointer to device information
 *
 * Functional Description:
 *   This function allocates additional resources such as the host memory
 *   blocks needed by the adapter.
 *   The adapter is also reset. The OS must call skfp_open() to open 
 *   the adapter and bring it on-line.
 *
 * Return Codes:
 *    0 - initialization succeeded
 *   -1 - initialization failed
 */
static  int skfp_driver_init(struct net_device *dev)
{
        struct s_smc *smc = netdev_priv(dev);
        skfddi_priv *bp = &smc->os;
        int err = -EIO;

        pr_debug(KERN_INFO "entering skfp_driver_init\n");

        // set the io address in private structures
        bp->base_addr = dev->base_addr;

        // Get the interrupt level from the PCI Configuration Table
        smc->hw.irq = dev->irq;

        spin_lock_init(&bp->DriverLock);
        
        // Allocate invalid frame
        bp->LocalRxBuffer = pci_alloc_consistent(&bp->pdev, MAX_FRAME_SIZE, &bp->LocalRxBufferDMA);
        if (!bp->LocalRxBuffer) {
                printk("could not allocate mem for ");
                printk("LocalRxBuffer: %d byte\n", MAX_FRAME_SIZE);
                goto fail;
        }

        // Determine the required size of the 'shared' memory area.
        bp->SharedMemSize = mac_drv_check_space();
        pr_debug(KERN_INFO "Memory for HWM: %ld\n", bp->SharedMemSize);
        if (bp->SharedMemSize > 0) {
                bp->SharedMemSize += 16;        // for descriptor alignment

                bp->SharedMemAddr = pci_alloc_consistent(&bp->pdev,
                                                         bp->SharedMemSize,
                                                         &bp->SharedMemDMA);
                if (!bp->SharedMemSize) {
                        printk("could not allocate mem for ");
                        printk("hardware module: %ld byte\n",
                               bp->SharedMemSize);
                        goto fail;
                }
                bp->SharedMemHeap = 0;  // Nothing used yet.

        } else {
                bp->SharedMemAddr = NULL;
                bp->SharedMemHeap = 0;
        }                       // SharedMemSize > 0

        memset(bp->SharedMemAddr, 0, bp->SharedMemSize);

        card_stop(smc);         // Reset adapter.

        pr_debug(KERN_INFO "mac_drv_init()..\n");
        if (mac_drv_init(smc) != 0) {
                pr_debug(KERN_INFO "mac_drv_init() failed.\n");
                goto fail;
        }
        read_address(smc, NULL);
        pr_debug(KERN_INFO "HW-Addr: %pMF\n", smc->hw.fddi_canon_addr.a);
        memcpy(dev->dev_addr, smc->hw.fddi_canon_addr.a, 6);

        smt_reset_defaults(smc, 0);

        return (0);

fail:
        if (bp->SharedMemAddr) {
                pci_free_consistent(&bp->pdev,
                                    bp->SharedMemSize,
                                    bp->SharedMemAddr,
                                    bp->SharedMemDMA);
                bp->SharedMemAddr = NULL;
        }
        if (bp->LocalRxBuffer) {
                pci_free_consistent(&bp->pdev, MAX_FRAME_SIZE,
                                    bp->LocalRxBuffer, bp->LocalRxBufferDMA);
                bp->LocalRxBuffer = NULL;
        }
        return err;
}                               // skfp_driver_init


/*
 * =============
 * = skfp_open =
 * =============
 *   
 * Overview:
 *   Opens the adapter
 *  
 * Returns:
 *   Condition code
 *       
 * Arguments:
 *   dev - pointer to device information
 *
 * Functional Description:
 *   This function brings the adapter to an operational state.
 *
 * Return Codes:
 *   0           - Adapter was successfully opened
 *   -EAGAIN - Could not register IRQ
 */
static int skfp_open(struct net_device *dev)
{
        struct s_smc *smc = netdev_priv(dev);
        int err;

        pr_debug(KERN_INFO "entering skfp_open\n");
        /* Register IRQ - support shared interrupts by passing device ptr */
        err = request_irq(dev->irq, skfp_interrupt, IRQF_SHARED,
                          dev->name, dev);
        if (err)
                return err;

        /*
         * Set current address to factory MAC address
         *
         * Note: We've already done this step in skfp_driver_init.
         *       However, it's possible that a user has set a node
         *               address override, then closed and reopened the
         *               adapter.  Unless we reset the device address field
         *               now, we'll continue to use the existing modified
         *               address.
         */
        read_address(smc, NULL);
        memcpy(dev->dev_addr, smc->hw.fddi_canon_addr.a, 6);

        init_smt(smc, NULL);
        smt_online(smc, 1);
        STI_FBI();

        /* Clear local multicast address tables */
        mac_clear_multicast(smc);

        /* Disable promiscuous filter settings */
        mac_drv_rx_mode(smc, RX_DISABLE_PROMISC);

        netif_start_queue(dev);
        return (0);
}                               // skfp_open


/*
 * ==============
 * = skfp_close =
 * ==============
 *   
 * Overview:
 *   Closes the device/module.
 *  
 * Returns:
 *   Condition code
 *       
 * Arguments:
 *   dev - pointer to device information
 *
 * Functional Description:
 *   This routine closes the adapter and brings it to a safe state.
 *   The interrupt service routine is deregistered with the OS.
 *   The adapter can be opened again with another call to skfp_open().
 *
 * Return Codes:
 *   Always return 0.
 *
 * Assumptions:
 *   No further requests for this adapter are made after this routine is
 *   called.  skfp_open() can be called to reset and reinitialize the
 *   adapter.
 */
static int skfp_close(struct net_device *dev)
{
        struct s_smc *smc = netdev_priv(dev);
        skfddi_priv *bp = &smc->os;

        CLI_FBI();
        smt_reset_defaults(smc, 1);
        card_stop(smc);
        mac_drv_clear_tx_queue(smc);
        mac_drv_clear_rx_queue(smc);

        netif_stop_queue(dev);
        /* Deregister (free) IRQ */
        free_irq(dev->irq, dev);

        skb_queue_purge(&bp->SendSkbQueue);
        bp->QueueSkb = MAX_TX_QUEUE_LEN;

        return (0);
}                               // skfp_close


/*
 * ==================
 * = skfp_interrupt =
 * ==================
 *   
 * Overview:
 *   Interrupt processing routine
 *  
 * Returns:
 *   None
 *       
 * Arguments:
 *   irq        - interrupt vector
 *   dev_id     - pointer to device information
 *
 * Functional Description:
 *   This routine calls the interrupt processing routine for this adapter.  It
 *   disables and reenables adapter interrupts, as appropriate.  We can support
 *   shared interrupts since the incoming dev_id pointer provides our device
 *   structure context. All the real work is done in the hardware module.
 *
 * Return Codes:
 *   None
 *
 * Assumptions:
 *   The interrupt acknowledgement at the hardware level (eg. ACKing the PIC
 *   on Intel-based systems) is done by the operating system outside this
 *   routine.
 *
 *       System interrupts are enabled through this call.
 *
 * Side Effects:
 *   Interrupts are disabled, then reenabled at the adapter.
 */

static irqreturn_t skfp_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct s_smc *smc;      /* private board structure pointer */
        skfddi_priv *bp;

        smc = netdev_priv(dev);
        bp = &smc->os;

        // IRQs enabled or disabled ?
        if (inpd(ADDR(B0_IMSK)) == 0) {
                // IRQs are disabled: must be shared interrupt
                return IRQ_NONE;
        }
        // Note: At this point, IRQs are enabled.
        if ((inpd(ISR_A) & smc->hw.is_imask) == 0) {    // IRQ?
                // Adapter did not issue an IRQ: must be shared interrupt
                return IRQ_NONE;
        }
        CLI_FBI();              // Disable IRQs from our adapter.
        spin_lock(&bp->DriverLock);

        // Call interrupt handler in hardware module (HWM).
        fddi_isr(smc);

        if (smc->os.ResetRequested) {
                ResetAdapter(smc);
                smc->os.ResetRequested = FALSE;
        }
        spin_unlock(&bp->DriverLock);
        STI_FBI();              // Enable IRQs from our adapter.

        return IRQ_HANDLED;
}                               // skfp_interrupt


/*
 * ======================
 * = skfp_ctl_get_stats =
 * ======================
 *   
 * Overview:
 *   Get statistics for FDDI adapter
 *  
 * Returns:
 *   Pointer to FDDI statistics structure
 *       
 * Arguments:
 *   dev - pointer to device information
 *
 * Functional Description:
 *   Gets current MIB objects from adapter, then
 *   returns FDDI statistics structure as defined
 *   in if_fddi.h.
 *
 *   Note: Since the FDDI statistics structure is
 *   still new and the device structure doesn't
 *   have an FDDI-specific get statistics handler,
 *   we'll return the FDDI statistics structure as
 *   a pointer to an Ethernet statistics structure.
 *   That way, at least the first part of the statistics
 *   structure can be decoded properly.
 *   We'll have to pay attention to this routine as the
 *   device structure becomes more mature and LAN media
 *   independent.
 *
 */
static struct net_device_stats *skfp_ctl_get_stats(struct net_device *dev)
{
        struct s_smc *bp = netdev_priv(dev);

        /* Fill the bp->stats structure with driver-maintained counters */

        bp->os.MacStat.port_bs_flag[0] = 0x1234;
        bp->os.MacStat.port_bs_flag[1] = 0x5678;
// goos: need to fill out fddi statistic
        return ((struct net_device_stats *) &bp->os.MacStat);
}                               // ctl_get_stat


/*
 * ==============================
 * = skfp_ctl_set_multicast_list =
 * ==============================
 *   
 * Overview:
 *   Enable/Disable LLC frame promiscuous mode reception
 *   on the adapter and/or update multicast address table.
 *  
 * Returns:
 *   None
 *       
 * Arguments:
 *   dev - pointer to device information
 *
 * Functional Description:
 *   This function acquires the driver lock and only calls
 *   skfp_ctl_set_multicast_list_wo_lock then.
 *   This routine follows a fairly simple algorithm for setting the
 *   adapter filters and CAM:
 *
 *      if IFF_PROMISC flag is set
 *              enable promiscuous mode
 *      else
 *              disable promiscuous mode
 *              if number of multicast addresses <= max. multicast number
 *                      add mc addresses to adapter table
 *              else
 *                      enable promiscuous mode
 *              update adapter filters
 *
 * Assumptions:
 *   Multicast addresses are presented in canonical (LSB) format.
 *
 * Side Effects:
 *   On-board adapter filters are updated.
 */
static void skfp_ctl_set_multicast_list(struct net_device *dev)
{
        struct s_smc *smc = netdev_priv(dev);
        skfddi_priv *bp = &smc->os;
        unsigned long Flags;

        spin_lock_irqsave(&bp->DriverLock, Flags);
        skfp_ctl_set_multicast_list_wo_lock(dev);
        spin_unlock_irqrestore(&bp->DriverLock, Flags);
}                               // skfp_ctl_set_multicast_list



static void skfp_ctl_set_multicast_list_wo_lock(struct net_device *dev)
{
        struct s_smc *smc = netdev_priv(dev);
        struct netdev_hw_addr *ha;

        /* Enable promiscuous mode, if necessary */
        if (dev->flags & IFF_PROMISC) {
                mac_drv_rx_mode(smc, RX_ENABLE_PROMISC);
                pr_debug(KERN_INFO "PROMISCUOUS MODE ENABLED\n");
        }
        /* Else, update multicast address table */
        else {
                mac_drv_rx_mode(smc, RX_DISABLE_PROMISC);
                pr_debug(KERN_INFO "PROMISCUOUS MODE DISABLED\n");

                // Reset all MC addresses
                mac_clear_multicast(smc);
                mac_drv_rx_mode(smc, RX_DISABLE_ALLMULTI);

                if (dev->flags & IFF_ALLMULTI) {
                        mac_drv_rx_mode(smc, RX_ENABLE_ALLMULTI);
                        pr_debug(KERN_INFO "ENABLE ALL MC ADDRESSES\n");
                } else if (!netdev_mc_empty(dev)) {
                        if (netdev_mc_count(dev) <= FPMAX_MULTICAST) {
                                /* use exact filtering */

                                // point to first multicast addr
                                netdev_for_each_mc_addr(ha, dev) {
                                        mac_add_multicast(smc,
                                                (struct fddi_addr *)ha->addr,
                                                1);

                                        pr_debug(KERN_INFO "ENABLE MC ADDRESS: %pMF\n",
                                                ha->addr);
                                }

                        } else {        // more MC addresses than HW supports

                                mac_drv_rx_mode(smc, RX_ENABLE_ALLMULTI);
                                pr_debug(KERN_INFO "ENABLE ALL MC ADDRESSES\n");
                        }
                } else {        // no MC addresses

                        pr_debug(KERN_INFO "DISABLE ALL MC ADDRESSES\n");
                }

                /* Update adapter filters */
                mac_update_multicast(smc);
        }
}                               // skfp_ctl_set_multicast_list_wo_lock


/*
 * ===========================
 * = skfp_ctl_set_mac_address =
 * ===========================
 *   
 * Overview:
 *   set new mac address on adapter and update dev_addr field in device table.
 *  
 * Returns:
 *   None
 *       
 * Arguments:
 *   dev  - pointer to device information
 *   addr - pointer to sockaddr structure containing unicast address to set
 *
 * Assumptions:
 *   The address pointed to by addr->sa_data is a valid unicast
 *   address and is presented in canonical (LSB) format.
 */
static int skfp_ctl_set_mac_address(struct net_device *dev, void *addr)
{
        struct s_smc *smc = netdev_priv(dev);
        struct sockaddr *p_sockaddr = (struct sockaddr *) addr;
        skfddi_priv *bp = &smc->os;
        unsigned long Flags;


        memcpy(dev->dev_addr, p_sockaddr->sa_data, FDDI_K_ALEN);
        spin_lock_irqsave(&bp->DriverLock, Flags);
        ResetAdapter(smc);
        spin_unlock_irqrestore(&bp->DriverLock, Flags);

        return (0);             /* always return zero */
}                               // skfp_ctl_set_mac_address


/*
 * ==============
 * = skfp_ioctl =
 * ==============
 *   
 * Overview:
 *
 * Perform IOCTL call functions here. Some are privileged operations and the
 * effective uid is checked in those cases.
 *  
 * Returns:
 *   status value
 *   0 - success
 *   other - failure
 *       
 * Arguments:
 *   dev  - pointer to device information
 *   rq - pointer to ioctl request structure
 *   cmd - ?
 *
 */


static int skfp_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
        struct s_smc *smc = netdev_priv(dev);
        skfddi_priv *lp = &smc->os;
        struct s_skfp_ioctl ioc;
        int status = 0;

        if (copy_from_user(&ioc, rq->ifr_data, sizeof(struct s_skfp_ioctl)))
                return -EFAULT;

        switch (ioc.cmd) {
        case SKFP_GET_STATS:    /* Get the driver statistics */
                ioc.len = sizeof(lp->MacStat);
                status = copy_to_user(ioc.data, skfp_ctl_get_stats(dev), ioc.len)
                                ? -EFAULT : 0;
                break;
        case SKFP_CLR_STATS:    /* Zero out the driver statistics */
                if (!capable(CAP_NET_ADMIN)) {
                        status = -EPERM;
                } else {
                        memset(&lp->MacStat, 0, sizeof(lp->MacStat));
                }
                break;
        default:
                printk("ioctl for %s: unknown cmd: %04x\n", dev->name, ioc.cmd);
                status = -EOPNOTSUPP;

        }                       // switch

        return status;
}                               // skfp_ioctl


/*
 * =====================
 * = skfp_send_pkt     =
 * =====================
 *   
 * Overview:
 *   Queues a packet for transmission and try to transmit it.
 *  
 * Returns:
 *   Condition code
 *       
 * Arguments:
 *   skb - pointer to sk_buff to queue for transmission
 *   dev - pointer to device information
 *
 * Functional Description:
 *   Here we assume that an incoming skb transmit request
 *   is contained in a single physically contiguous buffer
 *   in which the virtual address of the start of packet
 *   (skb->data) can be converted to a physical address
 *   by using pci_map_single().
 *
 *   We have an internal queue for packets we can not send 
 *   immediately. Packets in this queue can be given to the 
 *   adapter if transmit buffers are freed.
 *
 *   We can't free the skb until after it's been DMA'd
 *   out by the adapter, so we'll keep it in the driver and
 *   return it in mac_drv_tx_complete.
 *
 * Return Codes:
 *   0 - driver has queued and/or sent packet
 *       1 - caller should requeue the sk_buff for later transmission
 *
 * Assumptions:
 *   The entire packet is stored in one physically
 *   contiguous buffer which is not cached and whose
 *   32-bit physical address can be determined.
 *
 *   It's vital that this routine is NOT reentered for the
 *   same board and that the OS is not in another section of
 *   code (eg. skfp_interrupt) for the same board on a
 *   different thread.
 *
 * Side Effects:
 *   None
 */
static netdev_tx_t skfp_send_pkt(struct sk_buff *skb,
                                       struct net_device *dev)
{
        struct s_smc *smc = netdev_priv(dev);
        skfddi_priv *bp = &smc->os;

        pr_debug(KERN_INFO "skfp_send_pkt\n");

        /*
         * Verify that incoming transmit request is OK
         *
         * Note: The packet size check is consistent with other
         *               Linux device drivers, although the correct packet
         *               size should be verified before calling the
         *               transmit routine.
         */

        if (!(skb->len >= FDDI_K_LLC_ZLEN && skb->len <= FDDI_K_LLC_LEN)) {
                bp->MacStat.gen.tx_errors++;    /* bump error counter */
                // dequeue packets from xmt queue and send them
                netif_start_queue(dev);
                dev_kfree_skb(skb);
                return NETDEV_TX_OK;    /* return "success" */
        }
        if (bp->QueueSkb == 0) {        // return with tbusy set: queue full

                netif_stop_queue(dev);
                return NETDEV_TX_BUSY;
        }
        bp->QueueSkb--;
        skb_queue_tail(&bp->SendSkbQueue, skb);
        send_queued_packets(netdev_priv(dev));
        if (bp->QueueSkb == 0) {
                netif_stop_queue(dev);
        }
        return NETDEV_TX_OK;

}                               // skfp_send_pkt


/*
 * =======================
 * = send_queued_packets =
 * =======================
 *   
 * Overview:
 *   Send packets from the driver queue as long as there are some and
 *   transmit resources are available.
 *  
 * Returns:
 *   None
 *       
 * Arguments:
 *   smc - pointer to smc (adapter) structure
 *
 * Functional Description:
 *   Take a packet from queue if there is any. If not, then we are done.
 *   Check if there are resources to send the packet. If not, requeue it
 *   and exit. 
 *   Set packet descriptor flags and give packet to adapter.
 *   Check if any send resources can be freed (we do not use the
 *   transmit complete interrupt).
 */
static void send_queued_packets(struct s_smc *smc)
{
        skfddi_priv *bp = &smc->os;
        struct sk_buff *skb;
        unsigned char fc;
        int queue;
        struct s_smt_fp_txd *txd;       // Current TxD.
        dma_addr_t dma_address;
        unsigned long Flags;

        int frame_status;       // HWM tx frame status.

        pr_debug(KERN_INFO "send queued packets\n");
        for (;;) {
                // send first buffer from queue
                skb = skb_dequeue(&bp->SendSkbQueue);

                if (!skb) {
                        pr_debug(KERN_INFO "queue empty\n");
                        return;
                }               // queue empty !

                spin_lock_irqsave(&bp->DriverLock, Flags);
                fc = skb->data[0];
                queue = (fc & FC_SYNC_BIT) ? QUEUE_S : QUEUE_A0;
#ifdef ESS
                // Check if the frame may/must be sent as a synchronous frame.

                if ((fc & ~(FC_SYNC_BIT | FC_LLC_PRIOR)) == FC_ASYNC_LLC) {
                        // It's an LLC frame.
                        if (!smc->ess.sync_bw_available)
                                fc &= ~FC_SYNC_BIT; // No bandwidth available.

                        else {  // Bandwidth is available.

                                if (smc->mib.fddiESSSynchTxMode) {
                                        // Send as sync. frame.
                                        fc |= FC_SYNC_BIT;
                                }
                        }
                }
#endif                          // ESS
                frame_status = hwm_tx_init(smc, fc, 1, skb->len, queue);

                if ((frame_status & (LOC_TX | LAN_TX)) == 0) {
                        // Unable to send the frame.

                        if ((frame_status & RING_DOWN) != 0) {
                                // Ring is down.
                                pr_debug("Tx attempt while ring down.\n");
                        } else if ((frame_status & OUT_OF_TXD) != 0) {
                                pr_debug("%s: out of TXDs.\n", bp->dev->name);
                        } else {
                                pr_debug("%s: out of transmit resources",
                                        bp->dev->name);
                        }

                        // Note: We will retry the operation as soon as
                        // transmit resources become available.
                        skb_queue_head(&bp->SendSkbQueue, skb);
                        spin_unlock_irqrestore(&bp->DriverLock, Flags);
                        return; // Packet has been queued.

                }               // if (unable to send frame)

                bp->QueueSkb++; // one packet less in local queue

                // source address in packet ?
                CheckSourceAddress(skb->data, smc->hw.fddi_canon_addr.a);

                txd = (struct s_smt_fp_txd *) HWM_GET_CURR_TXD(smc, queue);

                dma_address = pci_map_single(&bp->pdev, skb->data,
                                             skb->len, PCI_DMA_TODEVICE);
                if (frame_status & LAN_TX) {
                        txd->txd_os.skb = skb;                  // save skb
                        txd->txd_os.dma_addr = dma_address;     // save dma mapping
                }
                hwm_tx_frag(smc, skb->data, dma_address, skb->len,
                      frame_status | FIRST_FRAG | LAST_FRAG | EN_IRQ_EOF);

                if (!(frame_status & LAN_TX)) {         // local only frame
                        pci_unmap_single(&bp->pdev, dma_address,
                                         skb->len, PCI_DMA_TODEVICE);
                        dev_kfree_skb_irq(skb);
                }
                spin_unlock_irqrestore(&bp->DriverLock, Flags);
        }                       // for

        return;                 // never reached

}                               // send_queued_packets


/************************
 * 
 * CheckSourceAddress
 *
 * Verify if the source address is set. Insert it if necessary.
 *
 ************************/
static void CheckSourceAddress(unsigned char *frame, unsigned char *hw_addr)
{
        unsigned char SRBit;

        if ((((unsigned long) frame[1 + 6]) & ~0x01) != 0) // source routing bit

                return;
        if ((unsigned short) frame[1 + 10] != 0)
                return;
        SRBit = frame[1 + 6] & 0x01;
        memcpy(&frame[1 + 6], hw_addr, 6);
        frame[8] |= SRBit;
}                               // CheckSourceAddress


/************************
 *
 *      ResetAdapter
 *
 *      Reset the adapter and bring it back to operational mode.
 * Args
 *      smc - A pointer to the SMT context struct.
 * Out
 *      Nothing.
 *
 ************************/
static void ResetAdapter(struct s_smc *smc)
{

        pr_debug(KERN_INFO "[fddi: ResetAdapter]\n");

        // Stop the adapter.

        card_stop(smc);         // Stop all activity.

        // Clear the transmit and receive descriptor queues.
        mac_drv_clear_tx_queue(smc);
        mac_drv_clear_rx_queue(smc);

        // Restart the adapter.

        smt_reset_defaults(smc, 1);     // Initialize the SMT module.

        init_smt(smc, (smc->os.dev)->dev_addr); // Initialize the hardware.

        smt_online(smc, 1);     // Insert into the ring again.
        STI_FBI();

        // Restore original receive mode (multicasts, promiscuous, etc.).
        skfp_ctl_set_multicast_list_wo_lock(smc->os.dev);
}                               // ResetAdapter


//--------------- functions called by hardware module ----------------

/************************
 *
 *      llc_restart_tx
 *
 *      The hardware driver calls this routine when the transmit complete
 *      interrupt bits (end of frame) for the synchronous or asynchronous
 *      queue is set.
 *
 * NOTE The hardware driver calls this function also if no packets are queued.
 *      The routine must be able to handle this case.
 * Args
 *      smc - A pointer to the SMT context struct.
 * Out
 *      Nothing.
 *
 ************************/
void llc_restart_tx(struct s_smc *smc)
{
        skfddi_priv *bp = &smc->os;

        pr_debug(KERN_INFO "[llc_restart_tx]\n");

        // Try to send queued packets
        spin_unlock(&bp->DriverLock);
        send_queued_packets(smc);
        spin_lock(&bp->DriverLock);
        netif_start_queue(bp->dev);// system may send again if it was blocked

}                               // llc_restart_tx


/************************
 *
 *      mac_drv_get_space
 *
 *      The hardware module calls this function to allocate the memory
 *      for the SMT MBufs if the define MB_OUTSIDE_SMC is specified.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      size - Size of memory in bytes to allocate.
 * Out
 *      != 0    A pointer to the virtual address of the allocated memory.
 *      == 0    Allocation error.
 *
 ************************/
void *mac_drv_get_space(struct s_smc *smc, unsigned int size)
{
        void *virt;

        pr_debug(KERN_INFO "mac_drv_get_space (%d bytes), ", size);
        virt = (void *) (smc->os.SharedMemAddr + smc->os.SharedMemHeap);

        if ((smc->os.SharedMemHeap + size) > smc->os.SharedMemSize) {
                printk("Unexpected SMT memory size requested: %d\n", size);
                return (NULL);
        }
        smc->os.SharedMemHeap += size;  // Move heap pointer.

        pr_debug(KERN_INFO "mac_drv_get_space end\n");
        pr_debug(KERN_INFO "virt addr: %lx\n", (ulong) virt);
        pr_debug(KERN_INFO "bus  addr: %lx\n", (ulong)
               (smc->os.SharedMemDMA +
                ((char *) virt - (char *)smc->os.SharedMemAddr)));
        return (virt);
}                               // mac_drv_get_space


/************************
 *
 *      mac_drv_get_desc_mem
 *
 *      This function is called by the hardware dependent module.
 *      It allocates the memory for the RxD and TxD descriptors.
 *
 *      This memory must be non-cached, non-movable and non-swappable.
 *      This memory should start at a physical page boundary.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      size - Size of memory in bytes to allocate.
 * Out
 *      != 0    A pointer to the virtual address of the allocated memory.
 *      == 0    Allocation error.
 *
 ************************/
void *mac_drv_get_desc_mem(struct s_smc *smc, unsigned int size)
{

        char *virt;

        pr_debug(KERN_INFO "mac_drv_get_desc_mem\n");

        // Descriptor memory must be aligned on 16-byte boundary.

        virt = mac_drv_get_space(smc, size);

        size = (u_int) (16 - (((unsigned long) virt) & 15UL));
        size = size % 16;

        pr_debug("Allocate %u bytes alignment gap ", size);
        pr_debug("for descriptor memory.\n");

        if (!mac_drv_get_space(smc, size)) {
                printk("fddi: Unable to align descriptor memory.\n");
                return (NULL);
        }
        return (virt + size);
}                               // mac_drv_get_desc_mem


/************************
 *
 *      mac_drv_virt2phys
 *
 *      Get the physical address of a given virtual address.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      virt - A (virtual) pointer into our 'shared' memory area.
 * Out
 *      Physical address of the given virtual address.
 *
 ************************/
unsigned long mac_drv_virt2phys(struct s_smc *smc, void *virt)
{
        return (smc->os.SharedMemDMA +
                ((char *) virt - (char *)smc->os.SharedMemAddr));
}                               // mac_drv_virt2phys


/************************
 *
 *      dma_master
 *
 *      The HWM calls this function, when the driver leads through a DMA
 *      transfer. If the OS-specific module must prepare the system hardware
 *      for the DMA transfer, it should do it in this function.
 *
 *      The hardware module calls this dma_master if it wants to send an SMT
 *      frame.  This means that the virt address passed in here is part of
 *      the 'shared' memory area.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      virt - The virtual address of the data.
 *
 *      len - The length in bytes of the data.
 *
 *      flag - Indicates the transmit direction and the buffer type:
 *              DMA_RD  (0x01)  system RAM ==> adapter buffer memory
 *              DMA_WR  (0x02)  adapter buffer memory ==> system RAM
 *              SMT_BUF (0x80)  SMT buffer
 *
 *      >> NOTE: SMT_BUF and DMA_RD are always set for PCI. <<
 * Out
 *      Returns the pyhsical address for the DMA transfer.
 *
 ************************/
u_long dma_master(struct s_smc * smc, void *virt, int len, int flag)
{
        return (smc->os.SharedMemDMA +
                ((char *) virt - (char *)smc->os.SharedMemAddr));
}                               // dma_master


/************************
 *
 *      dma_complete
 *
 *      The hardware module calls this routine when it has completed a DMA
 *      transfer. If the operating system dependent module has set up the DMA
 *      channel via dma_master() (e.g. Windows NT or AIX) it should clean up
 *      the DMA channel.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      descr - A pointer to a TxD or RxD, respectively.
 *
 *      flag - Indicates the DMA transfer direction / SMT buffer:
 *              DMA_RD  (0x01)  system RAM ==> adapter buffer memory
 *              DMA_WR  (0x02)  adapter buffer memory ==> system RAM
 *              SMT_BUF (0x80)  SMT buffer (managed by HWM)
 * Out
 *      Nothing.
 *
 ************************/
void dma_complete(struct s_smc *smc, volatile union s_fp_descr *descr, int flag)
{
        /* For TX buffers, there are two cases.  If it is an SMT transmit
         * buffer, there is nothing to do since we use consistent memory
         * for the 'shared' memory area.  The other case is for normal
         * transmit packets given to us by the networking stack, and in
         * that case we cleanup the PCI DMA mapping in mac_drv_tx_complete
         * below.
         *
         * For RX buffers, we have to unmap dynamic PCI DMA mappings here
         * because the hardware module is about to potentially look at
         * the contents of the buffer.  If we did not call the PCI DMA
         * unmap first, the hardware module could read inconsistent data.
         */
        if (flag & DMA_WR) {
                skfddi_priv *bp = &smc->os;
                volatile struct s_smt_fp_rxd *r = &descr->r;

                /* If SKB is NULL, we used the local buffer. */
                if (r->rxd_os.skb && r->rxd_os.dma_addr) {
                        int MaxFrameSize = bp->MaxFrameSize;

                        pci_unmap_single(&bp->pdev, r->rxd_os.dma_addr,
                                         MaxFrameSize, PCI_DMA_FROMDEVICE);
                        r->rxd_os.dma_addr = 0;
                }
        }
}                               // dma_complete


/************************
 *
 *      mac_drv_tx_complete
 *
 *      Transmit of a packet is complete. Release the tx staging buffer.
 *
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      txd - A pointer to the last TxD which is used by the frame.
 * Out
 *      Returns nothing.
 *
 ************************/
void mac_drv_tx_complete(struct s_smc *smc, volatile struct s_smt_fp_txd *txd)
{
        struct sk_buff *skb;

        pr_debug(KERN_INFO "entering mac_drv_tx_complete\n");
        // Check if this TxD points to a skb

        if (!(skb = txd->txd_os.skb)) {
                pr_debug("TXD with no skb assigned.\n");
                return;
        }
        txd->txd_os.skb = NULL;

        // release the DMA mapping
        pci_unmap_single(&smc->os.pdev, txd->txd_os.dma_addr,
                         skb->len, PCI_DMA_TODEVICE);
        txd->txd_os.dma_addr = 0;

        smc->os.MacStat.gen.tx_packets++;       // Count transmitted packets.
        smc->os.MacStat.gen.tx_bytes+=skb->len; // Count bytes

        // free the skb
        dev_kfree_skb_irq(skb);

        pr_debug(KERN_INFO "leaving mac_drv_tx_complete\n");
}                               // mac_drv_tx_complete


/************************
 *
 * dump packets to logfile
 *
 ************************/
#ifdef DUMPPACKETS
void dump_data(unsigned char *Data, int length)
{
        int i, j;
        unsigned char s[255], sh[10];
        if (length > 64) {
                length = 64;
        }
        printk(KERN_INFO "---Packet start---\n");
        for (i = 0, j = 0; i < length / 8; i++, j += 8)
                printk(KERN_INFO "%02x %02x %02x %02x %02x %02x %02x %02x\n",
                       Data[j + 0], Data[j + 1], Data[j + 2], Data[j + 3],
                       Data[j + 4], Data[j + 5], Data[j + 6], Data[j + 7]);
        strcpy(s, "");
        for (i = 0; i < length % 8; i++) {
                sprintf(sh, "%02x ", Data[j + i]);
                strcat(s, sh);
        }
        printk(KERN_INFO "%s\n", s);
        printk(KERN_INFO "------------------\n");
}                               // dump_data
#else
#define dump_data(data,len)
#endif                          // DUMPPACKETS

/************************
 *
 *      mac_drv_rx_complete
 *
 *      The hardware module calls this function if an LLC frame is received
 *      in a receive buffer. Also the SMT, NSA, and directed beacon frames
 *      from the network will be passed to the LLC layer by this function
 *      if passing is enabled.
 *
 *      mac_drv_rx_complete forwards the frame to the LLC layer if it should
 *      be received. It also fills the RxD ring with new receive buffers if
 *      some can be queued.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      rxd - A pointer to the first RxD which is used by the receive frame.
 *
 *      frag_count - Count of RxDs used by the received frame.
 *
 *      len - Frame length.
 * Out
 *      Nothing.
 *
 ************************/
void mac_drv_rx_complete(struct s_smc *smc, volatile struct s_smt_fp_rxd *rxd,
                         int frag_count, int len)
{
        skfddi_priv *bp = &smc->os;
        struct sk_buff *skb;
        unsigned char *virt, *cp;
        unsigned short ri;
        u_int RifLength;

        pr_debug(KERN_INFO "entering mac_drv_rx_complete (len=%d)\n", len);
        if (frag_count != 1) {  // This is not allowed to happen.

                printk("fddi: Multi-fragment receive!\n");
                goto RequeueRxd;        // Re-use the given RXD(s).

        }
        skb = rxd->rxd_os.skb;
        if (!skb) {
                pr_debug(KERN_INFO "No skb in rxd\n");
                smc->os.MacStat.gen.rx_errors++;
                goto RequeueRxd;
        }
        virt = skb->data;

        // The DMA mapping was released in dma_complete above.

        dump_data(skb->data, len);

        /*
         * FDDI Frame format:
         * +-------+-------+-------+------------+--------+------------+
         * | FC[1] | DA[6] | SA[6] | RIF[0..18] | LLC[3] | Data[0..n] |
         * +-------+-------+-------+------------+--------+------------+
         *
         * FC = Frame Control
         * DA = Destination Address
         * SA = Source Address
         * RIF = Routing Information Field
         * LLC = Logical Link Control
         */

        // Remove Routing Information Field (RIF), if present.

        if ((virt[1 + 6] & FDDI_RII) == 0)
                RifLength = 0;
        else {
                int n;
// goos: RIF removal has still to be tested
                pr_debug(KERN_INFO "RIF found\n");
                // Get RIF length from Routing Control (RC) field.
                cp = virt + FDDI_MAC_HDR_LEN;   // Point behind MAC header.

                ri = ntohs(*((__be16 *) cp));
                RifLength = ri & FDDI_RCF_LEN_MASK;
                if (len < (int) (FDDI_MAC_HDR_LEN + RifLength)) {
                        printk("fddi: Invalid RIF.\n");
                        goto RequeueRxd;        // Discard the frame.

                }
                virt[1 + 6] &= ~FDDI_RII;       // Clear RII bit.
                // regions overlap

                virt = cp + RifLength;
                for (n = FDDI_MAC_HDR_LEN; n; n--)
                        *--virt = *--cp;
                // adjust sbd->data pointer
                skb_pull(skb, RifLength);
                len -= RifLength;
                RifLength = 0;
        }

        // Count statistics.
        smc->os.MacStat.gen.rx_packets++;       // Count indicated receive
                                                // packets.
        smc->os.MacStat.gen.rx_bytes+=len;      // Count bytes.

        // virt points to header again
        if (virt[1] & 0x01) {   // Check group (multicast) bit.

                smc->os.MacStat.gen.multicast++;
        }

        // deliver frame to system
        rxd->rxd_os.skb = NULL;
        skb_trim(skb, len);
        skb->protocol = fddi_type_trans(skb, bp->dev);

        netif_rx(skb);

        HWM_RX_CHECK(smc, RX_LOW_WATERMARK);
        return;

      RequeueRxd:
        pr_debug(KERN_INFO "Rx: re-queue RXD.\n");
        mac_drv_requeue_rxd(smc, rxd, frag_count);
        smc->os.MacStat.gen.rx_errors++;        // Count receive packets
                                                // not indicated.

}                               // mac_drv_rx_complete


/************************
 *
 *      mac_drv_requeue_rxd
 *
 *      The hardware module calls this function to request the OS-specific
 *      module to queue the receive buffer(s) represented by the pointer
 *      to the RxD and the frag_count into the receive queue again. This
 *      buffer was filled with an invalid frame or an SMT frame.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      rxd - A pointer to the first RxD which is used by the receive frame.
 *
 *      frag_count - Count of RxDs used by the received frame.
 * Out
 *      Nothing.
 *
 ************************/
void mac_drv_requeue_rxd(struct s_smc *smc, volatile struct s_smt_fp_rxd *rxd,
                         int frag_count)
{
        volatile struct s_smt_fp_rxd *next_rxd;
        volatile struct s_smt_fp_rxd *src_rxd;
        struct sk_buff *skb;
        int MaxFrameSize;
        unsigned char *v_addr;
        dma_addr_t b_addr;

        if (frag_count != 1)    // This is not allowed to happen.

                printk("fddi: Multi-fragment requeue!\n");

        MaxFrameSize = smc->os.MaxFrameSize;
        src_rxd = rxd;
        for (; frag_count > 0; frag_count--) {
                next_rxd = src_rxd->rxd_next;
                rxd = HWM_GET_CURR_RXD(smc);

                skb = src_rxd->rxd_os.skb;
                if (skb == NULL) {      // this should not happen

                        pr_debug("Requeue with no skb in rxd!\n");
                        skb = alloc_skb(MaxFrameSize + 3, GFP_ATOMIC);
                        if (skb) {
                                // we got a skb
                                rxd->rxd_os.skb = skb;
                                skb_reserve(skb, 3);
                                skb_put(skb, MaxFrameSize);
                                v_addr = skb->data;
                                b_addr = pci_map_single(&smc->os.pdev,
                                                        v_addr,
                                                        MaxFrameSize,
                                                        PCI_DMA_FROMDEVICE);
                                rxd->rxd_os.dma_addr = b_addr;
                        } else {
                                // no skb available, use local buffer
                                pr_debug("Queueing invalid buffer!\n");
                                rxd->rxd_os.skb = NULL;
                                v_addr = smc->os.LocalRxBuffer;
                                b_addr = smc->os.LocalRxBufferDMA;
                        }
                } else {
                        // we use skb from old rxd
                        rxd->rxd_os.skb = skb;
                        v_addr = skb->data;
                        b_addr = pci_map_single(&smc->os.pdev,
                                                v_addr,
                                                MaxFrameSize,
                                                PCI_DMA_FROMDEVICE);
                        rxd->rxd_os.dma_addr = b_addr;
                }
                hwm_rx_frag(smc, v_addr, b_addr, MaxFrameSize,
                            FIRST_FRAG | LAST_FRAG);

                src_rxd = next_rxd;
        }
}                               // mac_drv_requeue_rxd


/************************
 *
 *      mac_drv_fill_rxd
 *
 *      The hardware module calls this function at initialization time
 *      to fill the RxD ring with receive buffers. It is also called by
 *      mac_drv_rx_complete if rx_free is large enough to queue some new
 *      receive buffers into the RxD ring. mac_drv_fill_rxd queues new
 *      receive buffers as long as enough RxDs and receive buffers are
 *      available.
 * Args
 *      smc - A pointer to the SMT context struct.
 * Out
 *      Nothing.
 *
 ************************/
void mac_drv_fill_rxd(struct s_smc *smc)
{
        int MaxFrameSize;
        unsigned char *v_addr;
        unsigned long b_addr;
        struct sk_buff *skb;
        volatile struct s_smt_fp_rxd *rxd;

        pr_debug(KERN_INFO "entering mac_drv_fill_rxd\n");

        // Walk through the list of free receive buffers, passing receive
        // buffers to the HWM as long as RXDs are available.

        MaxFrameSize = smc->os.MaxFrameSize;
        // Check if there is any RXD left.
        while (HWM_GET_RX_FREE(smc) > 0) {
                pr_debug(KERN_INFO ".\n");

                rxd = HWM_GET_CURR_RXD(smc);
                skb = alloc_skb(MaxFrameSize + 3, GFP_ATOMIC);
                if (skb) {
                        // we got a skb
                        skb_reserve(skb, 3);
                        skb_put(skb, MaxFrameSize);
                        v_addr = skb->data;
                        b_addr = pci_map_single(&smc->os.pdev,
                                                v_addr,
                                                MaxFrameSize,
                                                PCI_DMA_FROMDEVICE);
                        rxd->rxd_os.dma_addr = b_addr;
                } else {
                        // no skb available, use local buffer
                        // System has run out of buffer memory, but we want to
                        // keep the receiver running in hope of better times.
                        // Multiple descriptors may point to this local buffer,
                        // so data in it must be considered invalid.
                        pr_debug("Queueing invalid buffer!\n");
                        v_addr = smc->os.LocalRxBuffer;
                        b_addr = smc->os.LocalRxBufferDMA;
                }

                rxd->rxd_os.skb = skb;

                // Pass receive buffer to HWM.
                hwm_rx_frag(smc, v_addr, b_addr, MaxFrameSize,
                            FIRST_FRAG | LAST_FRAG);
        }
        pr_debug(KERN_INFO "leaving mac_drv_fill_rxd\n");
}                               // mac_drv_fill_rxd


/************************
 *
 *      mac_drv_clear_rxd
 *
 *      The hardware module calls this function to release unused
 *      receive buffers.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      rxd - A pointer to the first RxD which is used by the receive buffer.
 *
 *      frag_count - Count of RxDs used by the receive buffer.
 * Out
 *      Nothing.
 *
 ************************/
void mac_drv_clear_rxd(struct s_smc *smc, volatile struct s_smt_fp_rxd *rxd,
                       int frag_count)
{

        struct sk_buff *skb;

        pr_debug("entering mac_drv_clear_rxd\n");

        if (frag_count != 1)    // This is not allowed to happen.

                printk("fddi: Multi-fragment clear!\n");

        for (; frag_count > 0; frag_count--) {
                skb = rxd->rxd_os.skb;
                if (skb != NULL) {
                        skfddi_priv *bp = &smc->os;
                        int MaxFrameSize = bp->MaxFrameSize;

                        pci_unmap_single(&bp->pdev, rxd->rxd_os.dma_addr,
                                         MaxFrameSize, PCI_DMA_FROMDEVICE);

                        dev_kfree_skb(skb);
                        rxd->rxd_os.skb = NULL;
                }
                rxd = rxd->rxd_next;    // Next RXD.

        }
}                               // mac_drv_clear_rxd


/************************
 *
 *      mac_drv_rx_init
 *
 *      The hardware module calls this routine when an SMT or NSA frame of the
 *      local SMT should be delivered to the LLC layer.
 *
 *      It is necessary to have this function, because there is no other way to
 *      copy the contents of SMT MBufs into receive buffers.
 *
 *      mac_drv_rx_init allocates the required target memory for this frame,
 *      and receives the frame fragment by fragment by calling mac_drv_rx_frag.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      len - The length (in bytes) of the received frame (FC, DA, SA, Data).
 *
 *      fc - The Frame Control field of the received frame.
 *
 *      look_ahead - A pointer to the lookahead data buffer (may be NULL).
 *
 *      la_len - The length of the lookahead data stored in the lookahead
 *      buffer (may be zero).
 * Out
 *      Always returns zero (0).
 *
 ************************/
int mac_drv_rx_init(struct s_smc *smc, int len, int fc,
                    char *look_ahead, int la_len)
{
        struct sk_buff *skb;

        pr_debug("entering mac_drv_rx_init(len=%d)\n", len);

        // "Received" a SMT or NSA frame of the local SMT.

        if (len != la_len || len < FDDI_MAC_HDR_LEN || !look_ahead) {
                pr_debug("fddi: Discard invalid local SMT frame\n");
                pr_debug("  len=%d, la_len=%d, (ULONG) look_ahead=%08lXh.\n",
                       len, la_len, (unsigned long) look_ahead);
                return (0);
        }
        skb = alloc_skb(len + 3, GFP_ATOMIC);
        if (!skb) {
                pr_debug("fddi: Local SMT: skb memory exhausted.\n");
                return (0);
        }
        skb_reserve(skb, 3);
        skb_put(skb, len);
        skb_copy_to_linear_data(skb, look_ahead, len);

        // deliver frame to system
        skb->protocol = fddi_type_trans(skb, smc->os.dev);
        netif_rx(skb);

        return (0);
}                               // mac_drv_rx_init


/************************
 *
 *      smt_timer_poll
 *
 *      This routine is called periodically by the SMT module to clean up the
 *      driver.
 *
 *      Return any queued frames back to the upper protocol layers if the ring
 *      is down.
 * Args
 *      smc - A pointer to the SMT context struct.
 * Out
 *      Nothing.
 *
 ************************/
void smt_timer_poll(struct s_smc *smc)
{
}                               // smt_timer_poll


/************************
 *
 *      ring_status_indication
 *
 *      This function indicates a change of the ring state.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      status - The current ring status.
 * Out
 *      Nothing.
 *
 ************************/
void ring_status_indication(struct s_smc *smc, u_long status)
{
        pr_debug("ring_status_indication( ");
        if (status & RS_RES15)
                pr_debug("RS_RES15 ");
        if (status & RS_HARDERROR)
                pr_debug("RS_HARDERROR ");
        if (status & RS_SOFTERROR)
                pr_debug("RS_SOFTERROR ");
        if (status & RS_BEACON)
                pr_debug("RS_BEACON ");
        if (status & RS_PATHTEST)
                pr_debug("RS_PATHTEST ");
        if (status & RS_SELFTEST)
                pr_debug("RS_SELFTEST ");
        if (status & RS_RES9)
                pr_debug("RS_RES9 ");
        if (status & RS_DISCONNECT)
                pr_debug("RS_DISCONNECT ");
        if (status & RS_RES7)
                pr_debug("RS_RES7 ");
        if (status & RS_DUPADDR)
                pr_debug("RS_DUPADDR ");
        if (status & RS_NORINGOP)
                pr_debug("RS_NORINGOP ");
        if (status & RS_VERSION)
                pr_debug("RS_VERSION ");
        if (status & RS_STUCKBYPASSS)
                pr_debug("RS_STUCKBYPASSS ");
        if (status & RS_EVENT)
                pr_debug("RS_EVENT ");
        if (status & RS_RINGOPCHANGE)
                pr_debug("RS_RINGOPCHANGE ");
        if (status & RS_RES0)
                pr_debug("RS_RES0 ");
        pr_debug("]\n");
}                               // ring_status_indication


/************************
 *
 *      smt_get_time
 *
 *      Gets the current time from the system.
 * Args
 *      None.
 * Out
 *      The current time in TICKS_PER_SECOND.
 *
 *      TICKS_PER_SECOND has the unit 'count of timer ticks per second'. It is
 *      defined in "targetos.h". The definition of TICKS_PER_SECOND must comply
 *      to the time returned by smt_get_time().
 *
 ************************/
unsigned long smt_get_time(void)
{
        return jiffies;
}                               // smt_get_time


/************************
 *
 *      smt_stat_counter
 *
 *      Status counter update (ring_op, fifo full).
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      stat -  = 0: A ring operational change occurred.
 *              = 1: The FORMAC FIFO buffer is full / FIFO overflow.
 * Out
 *      Nothing.
 *
 ************************/
void smt_stat_counter(struct s_smc *smc, int stat)
{
//      BOOLEAN RingIsUp ;

        pr_debug(KERN_INFO "smt_stat_counter\n");
        switch (stat) {
        case 0:
                pr_debug(KERN_INFO "Ring operational change.\n");
                break;
        case 1:
                pr_debug(KERN_INFO "Receive fifo overflow.\n");
                smc->os.MacStat.gen.rx_errors++;
                break;
        default:
                pr_debug(KERN_INFO "Unknown status (%d).\n", stat);
                break;
        }
}                               // smt_stat_counter


/************************
 *
 *      cfm_state_change
 *
 *      Sets CFM state in custom statistics.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      c_state - Possible values are:
 *
 *              EC0_OUT, EC1_IN, EC2_TRACE, EC3_LEAVE, EC4_PATH_TEST,
 *              EC5_INSERT, EC6_CHECK, EC7_DEINSERT
 * Out
 *      Nothing.
 *
 ************************/
void cfm_state_change(struct s_smc *smc, int c_state)
{
#ifdef DRIVERDEBUG
        char *s;

        switch (c_state) {
        case SC0_ISOLATED:
                s = "SC0_ISOLATED";
                break;
        case SC1_WRAP_A:
                s = "SC1_WRAP_A";
                break;
        case SC2_WRAP_B:
                s = "SC2_WRAP_B";
                break;
        case SC4_THRU_A:
                s = "SC4_THRU_A";
                break;
        case SC5_THRU_B:
                s = "SC5_THRU_B";
                break;
        case SC7_WRAP_S:
                s = "SC7_WRAP_S";
                break;
        case SC9_C_WRAP_A:
                s = "SC9_C_WRAP_A";
                break;
        case SC10_C_WRAP_B:
                s = "SC10_C_WRAP_B";
                break;
        case SC11_C_WRAP_S:
                s = "SC11_C_WRAP_S";
                break;
        default:
                pr_debug(KERN_INFO "cfm_state_change: unknown %d\n", c_state);
                return;
        }
        pr_debug(KERN_INFO "cfm_state_change: %s\n", s);
#endif                          // DRIVERDEBUG
}                               // cfm_state_change


/************************
 *
 *      ecm_state_change
 *
 *      Sets ECM state in custom statistics.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      e_state - Possible values are:
 *
 *              SC0_ISOLATED, SC1_WRAP_A (5), SC2_WRAP_B (6), SC4_THRU_A (12),
 *              SC5_THRU_B (7), SC7_WRAP_S (8)
 * Out
 *      Nothing.
 *
 ************************/
void ecm_state_change(struct s_smc *smc, int e_state)
{
#ifdef DRIVERDEBUG
        char *s;

        switch (e_state) {
        case EC0_OUT:
                s = "EC0_OUT";
                break;
        case EC1_IN:
                s = "EC1_IN";
                break;
        case EC2_TRACE:
                s = "EC2_TRACE";
                break;
        case EC3_LEAVE:
                s = "EC3_LEAVE";
                break;
        case EC4_PATH_TEST:
                s = "EC4_PATH_TEST";
                break;
        case EC5_INSERT:
                s = "EC5_INSERT";
                break;
        case EC6_CHECK:
                s = "EC6_CHECK";
                break;
        case EC7_DEINSERT:
                s = "EC7_DEINSERT";
                break;
        default:
                s = "unknown";
                break;
        }
        pr_debug(KERN_INFO "ecm_state_change: %s\n", s);
#endif                          //DRIVERDEBUG
}                               // ecm_state_change


/************************
 *
 *      rmt_state_change
 *
 *      Sets RMT state in custom statistics.
 * Args
 *      smc - A pointer to the SMT context struct.
 *
 *      r_state - Possible values are:
 *
 *              RM0_ISOLATED, RM1_NON_OP, RM2_RING_OP, RM3_DETECT,
 *              RM4_NON_OP_DUP, RM5_RING_OP_DUP, RM6_DIRECTED, RM7_TRACE
 * Out
 *      Nothing.
 *
 ************************/
void rmt_state_change(struct s_smc *smc, int r_state)
{
#ifdef DRIVERDEBUG
        char *s;

        switch (r_state) {
        case RM0_ISOLATED:
                s = "RM0_ISOLATED";
                break;
        case RM1_NON_OP:
                s = "RM1_NON_OP - not operational";
                break;
        case RM2_RING_OP:
                s = "RM2_RING_OP - ring operational";
                break;
        case RM3_DETECT:
                s = "RM3_DETECT - detect dupl addresses";
                break;
        case RM4_NON_OP_DUP:
                s = "RM4_NON_OP_DUP - dupl. addr detected";
                break;
        case RM5_RING_OP_DUP:
                s = "RM5_RING_OP_DUP - ring oper. with dupl. addr";
                break;
        case RM6_DIRECTED:
                s = "RM6_DIRECTED - sending directed beacons";
                break;
        case RM7_TRACE:
                s = "RM7_TRACE - trace initiated";
                break;
        default:
                s = "unknown";
                break;
        }
        pr_debug(KERN_INFO "[rmt_state_change: %s]\n", s);
#endif                          // DRIVERDEBUG
}                               // rmt_state_change


/************************
 *
 *      drv_reset_indication
 *
 *      This function is called by the SMT when it has detected a severe
 *      hardware problem. The driver should perform a reset on the adapter
 *      as soon as possible, but not from within this function.
 * Args
 *      smc - A pointer to the SMT context struct.
 * Out
 *      Nothing.
 *
 ************************/
void drv_reset_indication(struct s_smc *smc)
{
        pr_debug(KERN_INFO "entering drv_reset_indication\n");

        smc->os.ResetRequested = TRUE;  // Set flag.

}                               // drv_reset_indication

static struct pci_driver skfddi_pci_driver = {
        .name           = "skfddi",
        .id_table       = skfddi_pci_tbl,
        .probe          = skfp_init_one,
        .remove         = __devexit_p(skfp_remove_one),
};

static int __init skfd_init(void)
{
        return pci_register_driver(&skfddi_pci_driver);
}

static void __exit skfd_exit(void)
{
        pci_unregister_driver(&skfddi_pci_driver);
}

module_init(skfd_init);
module_exit(skfd_exit);