path: root/drivers/net/wan/sdlamain.c

/*****************************************************************************
* sdlamain.c	WANPIPE(tm) Multiprotocol WAN Link Driver.  Main module.
*
* Author:	Nenad Corbic	<ncorbic@sangoma.com>
*		Gideon Hack	
*
* Copyright:	(c) 1995-1999 Sangoma Technologies Inc.
*
*		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.
* ============================================================================
* Sep 23, 1999  Nenad Corbic    Added support for SMP
* Sep 13, 1999  Nenad Corbic	Each port is treated as a separate device.
* Jun 02, 1999  Gideon Hack     Added support for the S514 adapter.
*				Updates for Linux 2.2.X kernels.
* Sep 17, 1998	Jaspreet Singh	Updated for 2.1.121+ kernel
* Nov 28, 1997	Jaspreet Singh	Changed DRV_RELEASE to 1
* Nov 10, 1997	Jaspreet Singh	Changed sti() to restore_flags();
* Nov 06, 1997 	Jaspreet Singh	Changed DRV_VERSION to 4 and DRV_RELEASE to 0
* Oct 20, 1997 	Jaspreet Singh	Modified sdla_isr routine so that card->in_isr
*				assignments are taken out and placed in the
*				sdla_ppp.c, sdla_fr.c and sdla_x25.c isr
*				routines. Took out 'wandev->tx_int_enabled' and
*				replaced it with 'wandev->enable_tx_int'. 
* May 29, 1997	Jaspreet Singh	Flow Control Problem
*				added "wandev->tx_int_enabled=1" line in the
*				init module. This line intializes the flag for 
*				preventing Interrupt disabled with device set to
*				busy
* Jan 15, 1997	Gene Kozin	Version 3.1.0
*				 o added UDP management stuff
* Jan 02, 1997	Gene Kozin	Initial version.
*****************************************************************************/

#include <linux/version.h>
#include <linux/config.h>	/* OS configuration options */
#include <linux/stddef.h>	/* offsetof(), etc. */
#include <linux/errno.h>	/* return codes */
#include <linux/string.h>	/* inline memset(), etc. */
#include <linux/slab.h>	/* kmalloc(), kfree() */
#include <linux/kernel.h>	/* printk(), and other useful stuff */
#include <linux/module.h>	/* support for loadable modules */
#include <linux/ioport.h>	/* request_region(), release_region() */
#include <linux/tqueue.h>	/* for kernel task queues */
#include <linux/wanrouter.h>	/* WAN router definitions */
#include <linux/wanpipe.h>	/* WANPIPE common user API definitions */
#include <asm/uaccess.h>	/* kernel <-> user copy */
#include <asm/io.h>		/* phys_to_virt() */
#include <linux/pci.h>
#include <linux/sdlapci.h>

/****** Defines & Macros ****************************************************/

#ifdef	_DEBUG_
#define	STATIC
#else
#define	STATIC		static
#endif

#define	DRV_VERSION	5		/* version number */
#define	DRV_RELEASE	0		/* release (minor version) number */
#define	MAX_CARDS	8		/* max number of adapters */

#ifndef	CONFIG_WANPIPE_CARDS		/* configurable option */
#define	CONFIG_WANPIPE_CARDS 1
#endif

#define	CMD_OK		0		/* normal firmware return code */
#define	CMD_TIMEOUT	0xFF		/* firmware command timed out */
#define	MAX_CMD_RETRY	10		/* max number of firmware retries */
/****** Function Prototypes *************************************************/

extern void disable_irq(unsigned int);
extern void enable_irq(unsigned int);
 
/* Module entry points */
int init_module (void);
void cleanup_module (void);

/* WAN link driver entry points */
static int setup    (wan_device_t* wandev, wandev_conf_t* conf);
static int shutdown (wan_device_t* wandev);
static int ioctl    (wan_device_t* wandev, unsigned cmd, unsigned long arg);

/* IOCTL handlers */
static int ioctl_dump	(sdla_t* card, sdla_dump_t* u_dump);
static int ioctl_exec	(sdla_t* card, sdla_exec_t* u_exec);

/* Miscellaneous functions */
STATIC void sdla_isr	(int irq, void* dev_id, struct pt_regs *regs);
STATIC void sdla_poll	(void* data);
static void release_hw  (sdla_t *card);

/****** Global Data **********************************************************
 * Note: All data must be explicitly initialized!!!
 */

/* private data */
static char drvname[]	= "wanpipe";
static char fullname[]	= "WANPIPE(tm) Multiprotocol Driver";
static char copyright[]	= "(c) 1995-1999 Sangoma Technologies Inc.";
static int ncards = CONFIG_WANPIPE_CARDS;
static int active;			/* number of active cards */
static sdla_t* card_array;	/* adapter data space */

/* Task queue element for creating a 'thread' */
static struct tq_struct sdla_tq = { routine: sdla_poll };

/******* Kernel Loadable Module Entry Points ********************************/

/*============================================================================
 * Module 'insert' entry point.
 * o print announcement
 * o allocate adapter data space
 * o initialize static data
 * o register all cards with WAN router
 * o calibrate SDLA shared memory access delay.
 *
 * Return:	0	Ok
 *		< 0	error.
 * Context:	process
 */
 
#ifdef MODULE
int init_module (void)
#else
int wanpipe_init2(void)
#endif
{
	int cnt, err = 0;

	printk(KERN_INFO "%s v%u.%u %s\n",
		fullname, DRV_VERSION, DRV_RELEASE, copyright);

	/* Verify number of cards and allocate adapter data space */
	ncards = min(ncards, MAX_CARDS);
	ncards = max(ncards, 1);
	card_array = kmalloc(sizeof(sdla_t) * ncards, GFP_KERNEL);
	if (card_array == NULL)
		return -ENOMEM;

	memset(card_array, 0, sizeof(sdla_t) * ncards);

	/* Register adapters with WAN router */
	for (cnt = 0; cnt < ncards; ++ cnt) {
		sdla_t* card = &card_array[cnt];
		wan_device_t* wandev = &card->wandev;

		card->next = NULL;
		sprintf(card->devname, "%s%d", drvname, cnt + 1);
		wandev->magic    = ROUTER_MAGIC;
		wandev->name     = card->devname;
		wandev->private  = card;
		wandev->enable_tx_int = 0;
		wandev->setup    = &setup;
		wandev->shutdown = &shutdown;
		wandev->ioctl    = &ioctl;
		err = register_wan_device(wandev);
		if (err) {
			printk(KERN_ERR
				"%s: %s registration failed with error %d!\n",
				drvname, card->devname, err);
			break;
		}
	}
	if (cnt){
		ncards = cnt;	/* adjust actual number of cards */
	}else {
		kfree(card_array);
		printk(KERN_INFO "IN Init Module: NO Cards registered\n");
		err = -ENODEV;
	}
	return err;
}

#ifdef MODULE
/*============================================================================
 * Module 'remove' entry point.
 * o unregister all adapters from the WAN router
 * o release all remaining system resources
 */
void cleanup_module (void)
{
	int i;

	for (i = 0; i < ncards; ++i) {
		sdla_t* card = &card_array[i];
		unregister_wan_device(card->devname);
	}
	kfree(card_array);
}

#endif

/******* WAN Device Driver Entry Points *************************************/

/*============================================================================
 * Setup/configure WAN link driver.
 * o check adapter state
 * o make sure firmware is present in configuration
 * o make sure I/O port and IRQ are specified
 * o make sure I/O region is available
 * o allocate interrupt vector
 * o setup SDLA hardware
 * o call appropriate routine to perform protocol-specific initialization
 * o mark I/O region as used
 * o if this is the first active card, then schedule background task
 *
 * This function is called when router handles ROUTER_SETUP IOCTL. The
 * configuration structure is in kernel memory (including extended data, if
 * any).
 */
 
static int setup (wan_device_t* wandev, wandev_conf_t* conf)
{
	sdla_t* card;
	int err = 0;
	int irq=0;
	int i;

	/* Sanity checks */
	if ((wandev == NULL) || (wandev->private == NULL) || (conf == NULL))
		return -EFAULT;
		
	card = wandev->private;
	if (wandev->state != WAN_UNCONFIGURED)
		return -EBUSY;		/* already configured */

	printk(KERN_INFO "\nProcessing WAN device %s...\n", wandev->name);

	/* Initialize the counters for each wandev 
	 * Used for counting number of times new_if and 
         * del_if get called.
	 */
	wandev->del_if_cnt = 0;
	wandev->new_if_cnt = 0;
	wandev->config_id  = conf->config_id;

	if (!conf->data_size || (conf->data == NULL)) {
		printk(KERN_ERR
			"%s: firmware not found in configuration data!\n",
			wandev->name);
		return -EINVAL;
	}

	/* only check I/O port and IRQ if not an S514 adapter */
	if(!conf->S514_CPU_no[0]) {

                if (conf->ioport <= 0) {
                        printk(KERN_ERR
			"%s: can't configure without I/O port address!\n",
			wandev->name);
                        return -EINVAL;
                }
	
                if (conf->irq <= 0) {
                        printk(KERN_ERR "%s: can't configure without IRQ!\n",
			wandev->name);
                        return -EINVAL;
                }

		/* Check for already loaded card with the same IO port and IRQ 
		 * If found, copy its hardware configuration and use its
		 * resources (i.e. piggybacking)
		 */
		if (!card->configured){
			for (i = 0; i < ncards; i ++) {
				sdla_t *nxt_card = &card_array[i];
				if (nxt_card->hw.port == conf->ioport && 
				    nxt_card != card && 
				    conf->config_id == WANCONFIG_CHDLC &&
				    nxt_card->wandev.config_id == WANCONFIG_CHDLC){
					irq = nxt_card->hw.irq;
					memcpy(&card->hw, &nxt_card->hw, sizeof(sdlahw_t));
					nxt_card->next = card;
					card->next = nxt_card;
					card->wandev.piggyback = WANOPT_YES;
				}
			}
			

			/* Make sure I/O port region is available */
			if (check_region(conf->ioport, SDLA_MAXIORANGE) && 
			    !card->wandev.piggyback) {
				printk(KERN_ERR
					"%s: I/O region 0x%X - 0x%X is in use!\n",
					wandev->name, conf->ioport,
					conf->ioport + SDLA_MAXIORANGE);
				return -EINVAL;
			}
		}
	}

	/* 
	For a S514 adapter, check for a possible configuration error in that
	we are loading an adapter in the same slot as a previously loaded S514
	card.
	*/ 
	else {
		if (!card->configured){
			for (i = 0; i < ncards; i ++) {
				sdla_t* nxt_card = &card_array[i];
				if(nxt_card == card)
					continue;
				if((nxt_card->hw.type == SDLA_S514) &&
				   (nxt_card->hw.S514_slot_no == conf->PCI_slot_no) &&
				   (nxt_card->hw.S514_cpu_no[0] == conf->S514_CPU_no[0])&&
				   (conf->config_id == WANCONFIG_CHDLC)&&
				   (nxt_card->wandev.config_id == WANCONFIG_CHDLC)){

					irq = nxt_card->hw.irq;
					memcpy(&card->hw, &nxt_card->hw, sizeof(sdlahw_t));
					nxt_card->next = card;
					card->next = nxt_card;
					card->wandev.piggyback = WANOPT_YES;
				}
			}
		}
	}

	/* If the current card has already been configured
         * or its a piggyback card, do not try to allocate
         * resources.
	 */
	if (!card->wandev.piggyback && !card->configured){

		/* Configure hardware, load firmware, etc. */
		memset(&card->hw, 0, sizeof(sdlahw_t));

		/* for an S514 adapter, pass the CPU number and the slot number read */
		/* from 'router.conf' to the 'sdla_setup()' function via the 'port' */
		/* parameter */
		if (conf->S514_CPU_no[0]){

			card->hw.S514_cpu_no[0] = conf->S514_CPU_no[0];
			card->hw.S514_slot_no = conf->PCI_slot_no;
			printk(KERN_INFO "Setting CPU to %c and Slot to %i\n",
				card->hw.S514_cpu_no[0], card->hw.S514_slot_no);

		}else{
			/* 508 Card io port and irq initialization */
			card->hw.port = conf->ioport;
			card->hw.irq = (conf->irq == 9) ? 2 : conf->irq;
		}


		/* Compute the virtual address of the card in kernel space */
		if(conf->maddr)
			card->hw.dpmbase = phys_to_virt(conf->maddr);
		else	/* But 0 means NULL */
			card->hw.dpmbase = (void *)conf->maddr;

		card->hw.dpmsize = SDLA_WINDOWSIZE;
		/* set the adapter type if using an S514 adapter */
		card->hw.type = (conf->S514_CPU_no[0]) ? SDLA_S514 : conf->hw_opt[0]; 
		card->hw.pclk = conf->hw_opt[1];

		err = sdla_setup(&card->hw, conf->data, conf->data_size);
		if (err){
			return err;
		}

	        if(card->hw.type != SDLA_S514)
			irq = (conf->irq == 2) ? 9 : conf->irq; /* IRQ2 -> IRQ9 */
		else
			irq = card->hw.irq;

		/* request an interrupt vector - note that interrupts may be shared */
		/* when using the S514 PCI adapter */
       		if(request_irq(irq, sdla_isr, 
		      (card->hw.type == SDLA_S514) ? SA_SHIRQ : 0, wandev->name, card)){

			printk(KERN_ERR "%s: Can't reserve IRQ %d!\n", wandev->name, irq);
			return -EINVAL;
		}

	}else{
		printk(KERN_INFO "%s: Card Configured %i or Piggybacking %i!\n",
			wandev->name,card->configured,card->wandev.piggyback);
	} 


	if (!card->configured){

	#ifdef CONFIG_SMP
		/* Initialize the Spin lock */
		printk(KERN_INFO "%s: Initializing SMP\n",wandev->name);
		spin_lock_init(&card->lock);
	#endif
		
		/* Intialize WAN device data space */
		wandev->irq       = irq;
		wandev->dma       = 0;
		if(card->hw.type != SDLA_S514){ 
			wandev->ioport = card->hw.port;
		}else{
			wandev->S514_cpu_no[0] = card->hw.S514_cpu_no[0];
			wandev->S514_slot_no = card->hw.S514_slot_no;
		}
		wandev->maddr     = (unsigned long)card->hw.dpmbase;
		wandev->msize     = card->hw.dpmsize;
		wandev->hw_opt[0] = card->hw.type;
		wandev->hw_opt[1] = card->hw.pclk;
		wandev->hw_opt[2] = card->hw.memory;
		wandev->hw_opt[3] = card->hw.fwid;
	}

	/* Protocol-specific initialization */
	switch (card->hw.fwid) {
#ifdef	CONFIG_WANPIPE_X25
	case SFID_X25_502:
	case SFID_X25_508:
		err = wpx_init(card, conf);
		break;
#endif

#ifdef	CONFIG_WANPIPE_FR
	case SFID_FR502:
	case SFID_FR508:
		err = wpf_init(card, conf);
		break;
#endif

#ifdef	CONFIG_WANPIPE_PPP
	case SFID_PPP502:
	case SFID_PPP508:
		err = wpp_init(card, conf);
		break;
#endif

#ifdef CONFIG_WANPIPE_CHDLC
	case SFID_CHDLC508:
	case SFID_CHDLC514:
//		if (conf->ft1){		
//			printk(KERN_INFO "%s: Starting FT1 Configurator\n",
//				card->devname);
//			err = wpft1_init(card, conf);
//		}else{
			err = wpc_init(card, conf);
//		}
		break;
#endif

#ifdef CONFIG_WANPIPE_BSTRM
	case SFID_BSC502:
		err = bsc_init(card, conf);
		break;
#endif

#ifdef CONFIG_WANPIPE_HDLC
	case SFID_HDLC508:
		err = hdlc_init(card, conf);
		break;
#endif

	default:
		printk(KERN_ERR "%s: this firmware is not supported %X %X!\n",
			wandev->name,card->hw.fwid,SFID_CHDLC508);
		err = -EINVAL;
	}


	if (err){
		release_hw(card);
		return err;
		
	}


  	/* Reserve I/O region and schedule background task */
        if(card->hw.type != SDLA_S514 && !card->wandev.piggyback)
                request_region(card->hw.port, card->hw.io_range, wandev->name);

	if (++active == 1) {
		MOD_INC_USE_COUNT;
		if (schedule_task(&sdla_tq) == 0)
			MOD_DEC_USE_COUNT;
	}
		
	wandev->critical = 0;
	return 0;
}

/*============================================================================
 * Shut down WAN link driver. 
 * o shut down adapter hardware
 * o release system resources.
 *
 * This function is called by the router when device is being unregistered or
 * when it handles ROUTER_DOWN IOCTL.
 */
static int shutdown (wan_device_t* wandev)
{
	sdla_t *card;

	/* sanity checks */
	if ((wandev == NULL) || (wandev->private == NULL))
		return -EFAULT;
		
	if (wandev->state == WAN_UNCONFIGURED)
		return 0;
		
	/* If we are in a critical section we lose */
	if (test_and_set_bit(0, (void*)&wandev->critical))
		return -EAGAIN;
		
	card = wandev->private;
	wandev->state = WAN_UNCONFIGURED;

	if (--active == 0)
		schedule();	/* stop background thread */

	/* Release Resources */
	release_hw(card);

        /* only free the allocated I/O range if not an S514 adapter */
	if (wandev->hw_opt[0] != SDLA_S514 && !card->configured){
              	release_region(card->hw.port, card->hw.io_range);
	}

	if (!card->configured){
		memset(&card->hw, 0, sizeof(sdlahw_t));
	      	if (card->next){
			memset(&card->next->hw, 0, sizeof(sdlahw_t));
		}
	}

	wandev->critical = 0;
	return 0;
}

static void release_hw (sdla_t *card)
{
	sdla_t *nxt_card;

	/* Check if next device exists */
	if (card->next){
		nxt_card = card->next;
		/* If next device is down then release resources */
		if (nxt_card->wandev.state == WAN_UNCONFIGURED){
			if (card->wandev.piggyback){
				/* If this device is piggyback then use
                                 * information of the master device 
				 */
				printk(KERN_INFO "%s: Piggyback shutting down\n",card->devname);
				sdla_down(&card->next->hw);
       				free_irq(card->wandev.irq, card->next);
				card->configured = 0;
				card->next->configured = 0;
				card->wandev.piggyback = 0;
			}else{
				/* Master device shutting down */
				printk(KERN_INFO "%s: Master shutting down\n",card->devname);
				sdla_down(&card->hw);
				free_irq(card->wandev.irq, card);
				card->configured = 0;
				card->next->configured = 0;
			}
		}else{
			printk(KERN_INFO "%s: Device still running\n",
				nxt_card->devname);
			card->configured = 1;
		}
	}else{
		printk(KERN_INFO "%s: Master shutting down\n",card->devname);
		sdla_down(&card->hw);
       		free_irq(card->wandev.irq, card);
		card->configured = 0;
	}
}


/*============================================================================
 * Driver I/O control. 
 * o verify arguments
 * o perform requested action
 *
 * This function is called when router handles one of the reserved user
 * IOCTLs.  Note that 'arg' stil points to user address space.
 */
static int ioctl (wan_device_t* wandev, unsigned cmd, unsigned long arg)
{
	sdla_t* card;
	int err;

	/* sanity checks */
	if ((wandev == NULL) || (wandev->private == NULL))
		return -EFAULT;
	if (wandev->state == WAN_UNCONFIGURED)
		return -ENODEV;

	card = wandev->private;

	if(card->hw.type != SDLA_S514){
		disable_irq(card->hw.irq);
	}

	if (test_and_set_bit(0, (void*)&wandev->critical)) {
		if(card->hw.type != SDLA_S514){
			enable_irq(card->hw.irq);
		}
		return -EAGAIN;
	}
	
	switch (cmd) {
	case WANPIPE_DUMP:
		err = ioctl_dump(wandev->private, (void*)arg);
		break;

	case WANPIPE_EXEC:
		err = ioctl_exec(wandev->private, (void*)arg);
		break;

	default:
		err = -EINVAL;
	}
 
	clear_bit(0, (void*)&wandev->critical);
        if(card->hw.type != SDLA_S514){
		enable_irq(card->hw.irq);
	}
 
	return err;
}

/****** Driver IOCTL Handlers ***********************************************/

/*============================================================================
 * Dump adapter memory to user buffer.
 * o verify request structure
 * o copy request structure to kernel data space
 * o verify length/offset
 * o verify user buffer
 * o copy adapter memory image to user buffer
 *
 * Note: when dumping memory, this routine switches current dual-port memory
 *	 vector, so care must be taken to avoid racing conditions.
 */
static int ioctl_dump (sdla_t* card, sdla_dump_t* u_dump)
{
	sdla_dump_t dump;
	unsigned winsize;
	unsigned long oldvec;	/* DPM window vector */
	unsigned long flags;
	int err = 0;

	if(copy_from_user((void*)&dump, (void*)u_dump, sizeof(sdla_dump_t)))
		return -EFAULT;
		
	if ((dump.magic != WANPIPE_MAGIC) ||
	    (dump.offset + dump.length > card->hw.memory))
		return -EINVAL;
	
	winsize = card->hw.dpmsize;
	save_flags(flags);
        cli();				/* >>> critical section start <<< */

	if(card->hw.type != SDLA_S514) {
                oldvec = card->hw.vector;
                while (dump.length) {
			/* current offset */				
                        unsigned pos = dump.offset % winsize;
			/* current vector */
                        unsigned long vec = dump.offset - pos;
                        unsigned len = (dump.length > (winsize - pos)) ?
                        	(winsize - pos) : dump.length;
			/* relocate window */
                        if (sdla_mapmem(&card->hw, vec) != 0) {
                                err = -EIO;
                                break;
                        }
                        /* FIXME::: COPY TO KERNEL BUFFER FIRST ?? */
                        sti();  /* Not ideal but tough we have to do this */
                        if(copy_to_user((void *)dump.ptr,
                                (u8 *)card->hw.dpmbase + pos, len)) 
                                return -EFAULT;
                        cli();
                        dump.length     -= len;
                        dump.offset     += len;
                        (char*)dump.ptr += len;
                }
                sdla_mapmem(&card->hw, oldvec);/* restore DPM window position */
        }
	
	else {
		/* FIXME::: COPY TO KERNEL BUFFER FIRST ?? */
                sti();  /* Not ideal but tough we have to do this */
               if(copy_to_user((void *)dump.ptr,
	                (u8 *)card->hw.dpmbase + dump.offset, dump.length))
                	return -EFAULT;
               cli();
	}

	restore_flags(flags);		/* >>> critical section end <<< */
	return err;
}

/*============================================================================
 * Execute adapter firmware command.
 * o verify request structure
 * o copy request structure to kernel data space
 * o call protocol-specific 'exec' function
 */
static int ioctl_exec (sdla_t* card, sdla_exec_t* u_exec)
{
	sdla_exec_t exec;

	if (card->exec == NULL)
		return -ENODEV;
	
	if(copy_from_user((void*)&exec, (void*)u_exec, sizeof(sdla_exec_t)))
		return -EFAULT;

	if ((exec.magic != WANPIPE_MAGIC) || (exec.cmd == NULL))
		return -EINVAL;
	return card->exec(card, exec.cmd, exec.data);
}

/******* Miscellaneous ******************************************************/

/*============================================================================
 * SDLA Interrupt Service Routine.
 * o acknowledge SDLA hardware interrupt.
 * o call protocol-specific interrupt service routine, if any.
 */
STATIC void sdla_isr (int irq, void* dev_id, struct pt_regs *regs)
{
#define	card	((sdla_t*)dev_id)

	if(card->hw.type == SDLA_S514) {	/* handle interrrupt on S514 */
                u32 int_status;
                unsigned char CPU_no = card->hw.S514_cpu_no[0];
                unsigned char card_found_for_IRQ;
		u8 IRQ_count = 0;

		for(;;) {

			read_S514_int_stat(&card->hw, &int_status);

			/* check if the interrupt is for this device */
 			if(!((unsigned char)int_status &
				(IRQ_CPU_A | IRQ_CPU_B)))
                	        return;

			/* if the IRQ is for both CPUs on the same adapter, */
			/* then alter the interrupt status so as to handle */
			/* one CPU at a time */
			if(((unsigned char)int_status & (IRQ_CPU_A | IRQ_CPU_B))
				== (IRQ_CPU_A | IRQ_CPU_B)) {
				int_status &= (CPU_no == S514_CPU_A) ?
					~IRQ_CPU_B : ~IRQ_CPU_A;
			}
 
			card_found_for_IRQ = 0;

	             	/* check to see that the CPU number for this device */
			/* corresponds to the interrupt status read */
                	switch (CPU_no) {
                        	case S514_CPU_A:
                                	if((unsigned char)int_status &
						IRQ_CPU_A)
                                        card_found_for_IRQ = 1;
                                break;

	                        case S514_CPU_B:
        	                        if((unsigned char)int_status &
						IRQ_CPU_B)
                                        card_found_for_IRQ = 1;
                                break;
                	}

			/* exit if the interrupt is for another CPU on the */
			/* same IRQ */
			if(!card_found_for_IRQ)
				return;

       	 		if (!card || 
			   (card->wandev.state == WAN_UNCONFIGURED && !card->configured)){
					printk(KERN_INFO
						"Received IRQ %d for CPU #%c\n",
						irq, CPU_no);
					printk(KERN_INFO
						"IRQ for unconfigured adapter\n");
					S514_intack(&card->hw, int_status);
					return;
       			}

	        	if (card->in_isr) {
        	       		printk(KERN_INFO
					"%s: interrupt re-entrancy on IRQ %d\n",
                       			card->devname, card->wandev.irq);
				S514_intack(&card->hw, int_status);
 				return;
       			}

	               	S514_intack(&card->hw, int_status);
 
       			if (card->isr)
				card->isr(card);

			/* handle a maximum of two interrupts (one for each */
			/* CPU on the adapter) before returning */  
			if((++ IRQ_count) == 2)
				return;
		}
	}

	else {			/* handle interrupt on S508 adapter */

		if (!card || ((card->wandev.state == WAN_UNCONFIGURED) && !card->configured))
			return;

		if (card->in_isr) {
			printk(KERN_INFO
				"%s: interrupt re-entrancy on IRQ %d!\n",
				card->devname, card->wandev.irq);
			return;
		}

		/* Use spin lock only for S508 */

#ifdef CONFIG_SMP
		spin_lock(&card->lock);
#endif
		sdla_intack(&card->hw);
		if (card->isr)
			card->isr(card);
#ifdef CONFIG_SMP
		spin_unlock(&card->lock);
#endif

	}
                
#undef	card
}

/*============================================================================
 * SDLA polling routine.
 * This routine simulates kernel thread to perform various housekeeping job.
 *
 * o for each configured device call its poll() routine
 * o if there is at least one active card, then reschedule itself once again
 */
STATIC void sdla_poll (void* data)
{
	int i;

	for (i = 0; i < ncards; ++i) {
		sdla_t* card = &card_array[i];

		if ((card->wandev.state != WAN_UNCONFIGURED) && card->poll &&
			!card->wandev.critical) {
			card->poll(card);
		}
	}
	if (active) {
		MOD_INC_USE_COUNT;
		if (schedule_task(&sdla_tq) == 0)	/* Surely not? */
			MOD_DEC_USE_COUNT;
	}
	MOD_DEC_USE_COUNT;
}

/*============================================================================
 * This routine is called by the protocol-specific modules when network
 * interface is being open.  The only reason we need this, is because we
 * have to call MOD_INC_USE_COUNT, but cannot include 'module.h' where it's
 * defined more than once into the same kernel module.
 */
void wanpipe_open (sdla_t* card)
{
	++card->open_cnt;
	MOD_INC_USE_COUNT;
}

/*============================================================================
 * This routine is called by the protocol-specific modules when network
 * interface is being closed.  The only reason we need this, is because we
 * have to call MOD_DEC_USE_COUNT, but cannot include 'module.h' where it's
 * defined more than once into the same kernel module.
 */
void wanpipe_close (sdla_t* card)
{
	--card->open_cnt;
	MOD_DEC_USE_COUNT;
}

/*============================================================================
 * Set WAN device state.
 */
void wanpipe_set_state (sdla_t* card, int state)
{
	unsigned long flags;

	save_flags(flags);
	cli();
	if (card->wandev.state != state) {
		switch (state) {
		case WAN_CONNECTED:
			printk (KERN_INFO "%s: link connected!\n",
				card->devname);
			break;

		case WAN_CONNECTING:
			printk (KERN_INFO "%s: link connecting...\n",
				card->devname);
			break;

		case WAN_DISCONNECTED:
			printk (KERN_INFO "%s: link disconnected!\n",
				card->devname);
			break;
		}
		card->wandev.state = state;
	}
	card->state_tick = jiffies;
	restore_flags(flags);
}

/****** End *****************************************************************/