sdlamain.c

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	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 curent 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 *****************************************************************/