arch/m68k/mac/macints.c - maze/linux - Git at Google

 /*
  *	Macintosh interrupts
  *
  * General design:
  * In contrary to the Amiga and Atari platforms, the Mac hardware seems to
  * exclusively use the autovector interrupts (the 'generic level0-level7'
  * interrupts with exception vectors 0x19-0x1f). The following interrupt levels
  * are used:
  *	1	- VIA1
  *		  - slot 0: one second interrupt (CA2)
  *		  - slot 1: VBlank (CA1)
  *		  - slot 2: ADB data ready (SR full)
  *		  - slot 3: ADB data  (CB2)
  *		  - slot 4: ADB clock (CB1)
  *		  - slot 5: timer 2
  *		  - slot 6: timer 1
  *		  - slot 7: status of IRQ; signals 'any enabled int.'
  *
  *	2	- VIA2 or RBV
  *		  - slot 0: SCSI DRQ (CA2)
  *		  - slot 1: NUBUS IRQ (CA1) need to read port A to find which
  *		  - slot 2: /EXP IRQ (only on IIci)
  *		  - slot 3: SCSI IRQ (CB2)
  *		  - slot 4: ASC IRQ (CB1)
  *		  - slot 5: timer 2 (not on IIci)
  *		  - slot 6: timer 1 (not on IIci)
  *		  - slot 7: status of IRQ; signals 'any enabled int.'
  *
  *	2	- OSS (IIfx only?)
  *		  - slot 0: SCSI interrupt
  *		  - slot 1: Sound interrupt
  *
  * Levels 3-6 vary by machine type. For VIA or RBV Macintoshes:
  *
  *	3	- unused (?)
  *
  *	4	- SCC
  *
  *	5	- unused (?)
  *		  [serial errors or special conditions seem to raise level 6
  *		  interrupts on some models (LC4xx?)]
  *
  *	6	- off switch (?)
  *
  * For OSS Macintoshes (IIfx only at this point):
  *
  *	3	- Nubus interrupt
  *		  - slot 0: Slot $9
  *		  - slot 1: Slot $A
  *		  - slot 2: Slot $B
  *		  - slot 3: Slot $C
  *		  - slot 4: Slot $D
  *		  - slot 5: Slot $E
  *
  *	4	- SCC IOP
  *
  *	5	- ISM IOP (ADB?)
  *
  *	6	- unused
  *
  * For PSC Macintoshes (660AV, 840AV):
  *
  *	3	- PSC level 3
  *		  - slot 0: MACE
  *
  *	4	- PSC level 4
  *		  - slot 1: SCC channel A interrupt
  *		  - slot 2: SCC channel B interrupt
  *		  - slot 3: MACE DMA
  *
  *	5	- PSC level 5
  *
  *	6	- PSC level 6
  *
  * Finally we have good 'ole level 7, the non-maskable interrupt:
  *
  *	7	- NMI (programmer's switch on the back of some Macs)
  *		  Also RAM parity error on models which support it (IIc, IIfx?)
  *
  * The current interrupt logic looks something like this:
  *
  * - We install dispatchers for the autovector interrupts (1-7). These
  *   dispatchers are responsible for querying the hardware (the
  *   VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using
  *   this information a machspec interrupt number is generated by placing the
  *   index of the interrupt hardware into the low three bits and the original
  *   autovector interrupt number in the upper 5 bits. The handlers for the
  *   resulting machspec interrupt are then called.
  *
  * - Nubus is a special case because its interrupts are hidden behind two
  *   layers of hardware. Nubus interrupts come in as index 1 on VIA #2,
  *   which translates to IRQ number 17. In this spot we install _another_
  *   dispatcher. This dispatcher finds the interrupting slot number (9-F) and
  *   then forms a new machspec interrupt number as above with the slot number
  *   minus 9 in the low three bits and the pseudo-level 7 in the upper five
  *   bits.  The handlers for this new machspec interrupt number are then
  *   called. This puts Nubus interrupts into the range 56-62.
  *
  * - The Baboon interrupts (used on some PowerBooks) are an even more special
  *   case. They're hidden behind the Nubus slot $C interrupt thus adding a
  *   third layer of indirection. Why oh why did the Apple engineers do that?
  *
  * - We support "fast" and "slow" handlers, just like the Amiga port. The
  *   fast handlers are called first and with all interrupts disabled. They
  *   are expected to execute quickly (hence the name). The slow handlers are
  *   called last with interrupts enabled and the interrupt level restored.
  *   They must therefore be reentrant.
  *
  *   TODO:
  *
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/kernel_stat.h>
 #include <linux/interrupt.h> /* for intr_count */
 #include <linux/delay.h>
 #include <linux/seq_file.h>

 #include <asm/system.h>
 #include <asm/irq.h>
 #include <asm/traps.h>
 #include <asm/bootinfo.h>
 #include <asm/macintosh.h>
 #include <asm/mac_via.h>
 #include <asm/mac_psc.h>
 #include <asm/hwtest.h>
 #include <asm/errno.h>
 #include <asm/macints.h>
 #include <asm/irq_regs.h>
 #include <asm/mac_oss.h>

 #define SHUTUP_SONIC

 /*
  * VIA/RBV hooks
  */

 extern void via_register_interrupts(void);
 extern void via_irq_enable(int);
 extern void via_irq_disable(int);
 extern void via_irq_clear(int);
 extern int  via_irq_pending(int);

 /*
  * OSS hooks
  */

 extern void oss_register_interrupts(void);
 extern void oss_irq_enable(int);
 extern void oss_irq_disable(int);
 extern void oss_irq_clear(int);
 extern int  oss_irq_pending(int);

 /*
  * PSC hooks
  */

 extern void psc_register_interrupts(void);
 extern void psc_irq_enable(int);
 extern void psc_irq_disable(int);
 extern void psc_irq_clear(int);
 extern int  psc_irq_pending(int);

 /*
  * IOP hooks
  */

 extern void iop_register_interrupts(void);

 /*
  * Baboon hooks
  */

 extern int baboon_present;

 extern void baboon_register_interrupts(void);
 extern void baboon_irq_enable(int);
 extern void baboon_irq_disable(int);
 extern void baboon_irq_clear(int);

 /*
  * console_loglevel determines NMI handler function
  */

 irqreturn_t mac_nmi_handler(int, void *);
 irqreturn_t mac_debug_handler(int, void *);

 /* #define DEBUG_MACINTS */

 void mac_enable_irq(unsigned int irq);
 void mac_disable_irq(unsigned int irq);

 static struct irq_controller mac_irq_controller = {
 	.name		= "mac",
 	.lock		= __SPIN_LOCK_UNLOCKED(mac_irq_controller.lock),
 	.enable		= mac_enable_irq,
 	.disable	= mac_disable_irq,
 };

 void __init mac_init_IRQ(void)
 {
 #ifdef DEBUG_MACINTS
 	printk("mac_init_IRQ(): Setting things up...\n");
 #endif
 	m68k_setup_irq_controller(&mac_irq_controller, IRQ_USER,
 				  NUM_MAC_SOURCES - IRQ_USER);
 	/* Make sure the SONIC interrupt is cleared or things get ugly */
 #ifdef SHUTUP_SONIC
 	printk("Killing onboard sonic... ");
 	/* This address should hopefully be mapped already */
 	if (hwreg_present((void*)(0x50f0a000))) {
 		*(long *)(0x50f0a014) = 0x7fffL;
 		*(long *)(0x50f0a010) = 0L;
 	}
 	printk("Done.\n");
 #endif /* SHUTUP_SONIC */

 	/*
 	 * Now register the handlers for the master IRQ handlers
 	 * at levels 1-7. Most of the work is done elsewhere.
 	 */

 	if (oss_present)
 		oss_register_interrupts();
 	else
 		via_register_interrupts();
 	if (psc_present)
 		psc_register_interrupts();
 	if (baboon_present)
 		baboon_register_interrupts();
 	iop_register_interrupts();
 	if (request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI",
 			mac_nmi_handler))
 		pr_err("Couldn't register NMI\n");
 #ifdef DEBUG_MACINTS
 	printk("mac_init_IRQ(): Done!\n");
 #endif
 }

 /*
  *  mac_enable_irq - enable an interrupt source
  * mac_disable_irq - disable an interrupt source
  *   mac_clear_irq - clears a pending interrupt
  * mac_pending_irq - Returns the pending status of an IRQ (nonzero = pending)
  *
  * These routines are just dispatchers to the VIA/OSS/PSC routines.
  */

 void mac_enable_irq(unsigned int irq)
 {
 	int irq_src = IRQ_SRC(irq);

 	switch(irq_src) {
 	case 1:
 		via_irq_enable(irq);
 		break;
 	case 2:
 	case 7:
 		if (oss_present)
 			oss_irq_enable(irq);
 		else
 			via_irq_enable(irq);
 		break;
 	case 3:
 	case 5:
 	case 6:
 		if (psc_present)
 			psc_irq_enable(irq);
 		else if (oss_present)
 			oss_irq_enable(irq);
 		break;
 	case 4:
 		if (psc_present)
 			psc_irq_enable(irq);
 		break;
 	case 8:
 		if (baboon_present)
 			baboon_irq_enable(irq);
 		break;
 	}
 }

 void mac_disable_irq(unsigned int irq)
 {
 	int irq_src = IRQ_SRC(irq);

 	switch(irq_src) {
 	case 1:
 		via_irq_disable(irq);
 		break;
 	case 2:
 	case 7:
 		if (oss_present)
 			oss_irq_disable(irq);
 		else
 			via_irq_disable(irq);
 		break;
 	case 3:
 	case 5:
 	case 6:
 		if (psc_present)
 			psc_irq_disable(irq);
 		else if (oss_present)
 			oss_irq_disable(irq);
 		break;
 	case 4:
 		if (psc_present)
 			psc_irq_disable(irq);
 		break;
 	case 8:
 		if (baboon_present)
 			baboon_irq_disable(irq);
 		break;
 	}
 }

 void mac_clear_irq(unsigned int irq)
 {
 	switch(IRQ_SRC(irq)) {
 	case 1:
 		via_irq_clear(irq);
 		break;
 	case 2:
 	case 7:
 		if (oss_present)
 			oss_irq_clear(irq);
 		else
 			via_irq_clear(irq);
 		break;
 	case 3:
 	case 5:
 	case 6:
 		if (psc_present)
 			psc_irq_clear(irq);
 		else if (oss_present)
 			oss_irq_clear(irq);
 		break;
 	case 4:
 		if (psc_present)
 			psc_irq_clear(irq);
 		break;
 	case 8:
 		if (baboon_present)
 			baboon_irq_clear(irq);
 		break;
 	}
 }

 int mac_irq_pending(unsigned int irq)
 {
 	switch(IRQ_SRC(irq)) {
 	case 1:
 		return via_irq_pending(irq);
 	case 2:
 	case 7:
 		if (oss_present)
 			return oss_irq_pending(irq);
 		else
 			return via_irq_pending(irq);
 	case 3:
 	case 5:
 	case 6:
 		if (psc_present)
 			return psc_irq_pending(irq);
 		else if (oss_present)
 			return oss_irq_pending(irq);
 		break;
 	case 4:
 		if (psc_present)
 			return psc_irq_pending(irq);
 		break;
 	}
 	return 0;
 }
 EXPORT_SYMBOL(mac_irq_pending);

 static int num_debug[8];

 irqreturn_t mac_debug_handler(int irq, void *dev_id)
 {
 	if (num_debug[irq] < 10) {
 		printk("DEBUG: Unexpected IRQ %d\n", irq);
 		num_debug[irq]++;
 	}
 	return IRQ_HANDLED;
 }

 static int in_nmi;
 static volatile int nmi_hold;

 irqreturn_t mac_nmi_handler(int irq, void *dev_id)
 {
 	int i;
 	/*
 	 * generate debug output on NMI switch if 'debug' kernel option given
 	 * (only works with Penguin!)
 	 */

 	in_nmi++;
 	for (i=0; i<100; i++)
 		udelay(1000);

 	if (in_nmi == 1) {
 		nmi_hold = 1;
 		printk("... pausing, press NMI to resume ...");
 	} else {
 		printk(" ok!\n");
 		nmi_hold = 0;
 	}

 	barrier();

 	while (nmi_hold == 1)
 		udelay(1000);

 	if (console_loglevel >= 8) {
 #if 0
 		struct pt_regs *fp = get_irq_regs();
 		show_state();
 		printk("PC: %08lx\nSR: %04x  SP: %p\n", fp->pc, fp->sr, fp);
 		printk("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
 		       fp->d0, fp->d1, fp->d2, fp->d3);
 		printk("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
 		       fp->d4, fp->d5, fp->a0, fp->a1);

 		if (STACK_MAGIC != *(unsigned long *)current->kernel_stack_page)
 			printk("Corrupted stack page\n");
 		printk("Process %s (pid: %d, stackpage=%08lx)\n",
 			current->comm, current->pid, current->kernel_stack_page);
 		if (intr_count == 1)
 			dump_stack((struct frame *)fp);
 #else
 		/* printk("NMI "); */
 #endif
 	}
 	in_nmi--;
 	return IRQ_HANDLED;
 }
	/*
	* Macintosh interrupts
	*
	* General design:
	* In contrary to the Amiga and Atari platforms, the Mac hardware seems to
	* exclusively use the autovector interrupts (the 'generic level0-level7'
	* interrupts with exception vectors 0x19-0x1f). The following interrupt levels
	* are used:
	* 1 - VIA1
	* - slot 0: one second interrupt (CA2)
	* - slot 1: VBlank (CA1)
	* - slot 2: ADB data ready (SR full)
	* - slot 3: ADB data (CB2)
	* - slot 4: ADB clock (CB1)
	* - slot 5: timer 2
	* - slot 6: timer 1
	* - slot 7: status of IRQ; signals 'any enabled int.'
	*
	* 2 - VIA2 or RBV
	* - slot 0: SCSI DRQ (CA2)
	* - slot 1: NUBUS IRQ (CA1) need to read port A to find which
	* - slot 2: /EXP IRQ (only on IIci)
	* - slot 3: SCSI IRQ (CB2)
	* - slot 4: ASC IRQ (CB1)
	* - slot 5: timer 2 (not on IIci)
	* - slot 6: timer 1 (not on IIci)
	* - slot 7: status of IRQ; signals 'any enabled int.'
	*
	* 2 - OSS (IIfx only?)
	* - slot 0: SCSI interrupt
	* - slot 1: Sound interrupt
	*
	* Levels 3-6 vary by machine type. For VIA or RBV Macintoshes:
	*
	* 3 - unused (?)
	*
	* 4 - SCC
	*
	* 5 - unused (?)
	* [serial errors or special conditions seem to raise level 6
	* interrupts on some models (LC4xx?)]
	*
	* 6 - off switch (?)
	*
	* For OSS Macintoshes (IIfx only at this point):
	*
	* 3 - Nubus interrupt
	* - slot 0: Slot $9
	* - slot 1: Slot $A
	* - slot 2: Slot $B
	* - slot 3: Slot $C
	* - slot 4: Slot $D
	* - slot 5: Slot $E
	*
	* 4 - SCC IOP
	*
	* 5 - ISM IOP (ADB?)
	*
	* 6 - unused
	*
	* For PSC Macintoshes (660AV, 840AV):
	*
	* 3 - PSC level 3
	* - slot 0: MACE
	*
	* 4 - PSC level 4
	* - slot 1: SCC channel A interrupt
	* - slot 2: SCC channel B interrupt
	* - slot 3: MACE DMA
	*
	* 5 - PSC level 5
	*
	* 6 - PSC level 6
	*
	* Finally we have good 'ole level 7, the non-maskable interrupt:
	*
	* 7 - NMI (programmer's switch on the back of some Macs)
	* Also RAM parity error on models which support it (IIc, IIfx?)
	*
	* The current interrupt logic looks something like this:
	*
	* - We install dispatchers for the autovector interrupts (1-7). These
	* dispatchers are responsible for querying the hardware (the
	* VIA/RBV/OSS/PSC chips) to determine the actual interrupt source. Using
	* this information a machspec interrupt number is generated by placing the
	* index of the interrupt hardware into the low three bits and the original
	* autovector interrupt number in the upper 5 bits. The handlers for the
	* resulting machspec interrupt are then called.
	*
	* - Nubus is a special case because its interrupts are hidden behind two
	* layers of hardware. Nubus interrupts come in as index 1 on VIA #2,
	* which translates to IRQ number 17. In this spot we install _another_
	* dispatcher. This dispatcher finds the interrupting slot number (9-F) and
	* then forms a new machspec interrupt number as above with the slot number
	* minus 9 in the low three bits and the pseudo-level 7 in the upper five
	* bits. The handlers for this new machspec interrupt number are then
	* called. This puts Nubus interrupts into the range 56-62.
	*
	* - The Baboon interrupts (used on some PowerBooks) are an even more special
	* case. They're hidden behind the Nubus slot $C interrupt thus adding a
	* third layer of indirection. Why oh why did the Apple engineers do that?
	*
	* - We support "fast" and "slow" handlers, just like the Amiga port. The
	* fast handlers are called first and with all interrupts disabled. They
	* are expected to execute quickly (hence the name). The slow handlers are
	* called last with interrupts enabled and the interrupt level restored.
	* They must therefore be reentrant.
	*
	* TODO:
	*
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/sched.h>
	#include <linux/kernel_stat.h>
	#include <linux/interrupt.h> /* for intr_count */
	#include <linux/delay.h>
	#include <linux/seq_file.h>

	#include <asm/system.h>
	#include <asm/irq.h>
	#include <asm/traps.h>
	#include <asm/bootinfo.h>
	#include <asm/macintosh.h>
	#include <asm/mac_via.h>
	#include <asm/mac_psc.h>
	#include <asm/hwtest.h>
	#include <asm/errno.h>
	#include <asm/macints.h>
	#include <asm/irq_regs.h>
	#include <asm/mac_oss.h>

	#define SHUTUP_SONIC

	/*
	* VIA/RBV hooks
	*/

	extern void via_register_interrupts(void);
	extern void via_irq_enable(int);
	extern void via_irq_disable(int);
	extern void via_irq_clear(int);
	extern int via_irq_pending(int);

	/*
	* OSS hooks
	*/

	extern void oss_register_interrupts(void);
	extern void oss_irq_enable(int);
	extern void oss_irq_disable(int);
	extern void oss_irq_clear(int);
	extern int oss_irq_pending(int);

	/*
	* PSC hooks
	*/

	extern void psc_register_interrupts(void);
	extern void psc_irq_enable(int);
	extern void psc_irq_disable(int);
	extern void psc_irq_clear(int);
	extern int psc_irq_pending(int);

	/*
	* IOP hooks
	*/

	extern void iop_register_interrupts(void);

	/*
	* Baboon hooks
	*/

	extern int baboon_present;

	extern void baboon_register_interrupts(void);
	extern void baboon_irq_enable(int);
	extern void baboon_irq_disable(int);
	extern void baboon_irq_clear(int);

	/*
	* console_loglevel determines NMI handler function
	*/

	irqreturn_t mac_nmi_handler(int, void *);
	irqreturn_t mac_debug_handler(int, void *);

	/* #define DEBUG_MACINTS */

	void mac_enable_irq(unsigned int irq);
	void mac_disable_irq(unsigned int irq);

	static struct irq_controller mac_irq_controller = {
	.name = "mac",
	.lock = __SPIN_LOCK_UNLOCKED(mac_irq_controller.lock),
	.enable = mac_enable_irq,
	.disable = mac_disable_irq,
	};

	void __init mac_init_IRQ(void)
	{
	#ifdef DEBUG_MACINTS
	printk("mac_init_IRQ(): Setting things up...\n");
	#endif
	m68k_setup_irq_controller(&mac_irq_controller, IRQ_USER,
	NUM_MAC_SOURCES - IRQ_USER);
	/* Make sure the SONIC interrupt is cleared or things get ugly */
	#ifdef SHUTUP_SONIC
	printk("Killing onboard sonic... ");
	/* This address should hopefully be mapped already */
	if (hwreg_present((void*)(0x50f0a000))) {
	(long )(0x50f0a014) = 0x7fffL;
	(long )(0x50f0a010) = 0L;
	}
	printk("Done.\n");
	#endif /* SHUTUP_SONIC */

	/*
	* Now register the handlers for the master IRQ handlers
	* at levels 1-7. Most of the work is done elsewhere.
	*/

	if (oss_present)
	oss_register_interrupts();
	else
	via_register_interrupts();
	if (psc_present)
	psc_register_interrupts();
	if (baboon_present)
	baboon_register_interrupts();
	iop_register_interrupts();
	if (request_irq(IRQ_AUTO_7, mac_nmi_handler, 0, "NMI",
	mac_nmi_handler))
	pr_err("Couldn't register NMI\n");
	#ifdef DEBUG_MACINTS
	printk("mac_init_IRQ(): Done!\n");
	#endif
	}

	/*
	* mac_enable_irq - enable an interrupt source
	* mac_disable_irq - disable an interrupt source
	* mac_clear_irq - clears a pending interrupt
	* mac_pending_irq - Returns the pending status of an IRQ (nonzero = pending)
	*
	* These routines are just dispatchers to the VIA/OSS/PSC routines.
	*/

	void mac_enable_irq(unsigned int irq)
	{
	int irq_src = IRQ_SRC(irq);

	switch(irq_src) {
	case 1:
	via_irq_enable(irq);
	break;
	case 2:
	case 7:
	if (oss_present)
	oss_irq_enable(irq);
	else
	via_irq_enable(irq);
	break;
	case 3:
	case 5:
	case 6:
	if (psc_present)
	psc_irq_enable(irq);
	else if (oss_present)
	oss_irq_enable(irq);
	break;
	case 4:
	if (psc_present)
	psc_irq_enable(irq);
	break;
	case 8:
	if (baboon_present)
	baboon_irq_enable(irq);
	break;
	}
	}

	void mac_disable_irq(unsigned int irq)
	{
	int irq_src = IRQ_SRC(irq);

	switch(irq_src) {
	case 1:
	via_irq_disable(irq);
	break;
	case 2:
	case 7:
	if (oss_present)
	oss_irq_disable(irq);
	else
	via_irq_disable(irq);
	break;
	case 3:
	case 5:
	case 6:
	if (psc_present)
	psc_irq_disable(irq);
	else if (oss_present)
	oss_irq_disable(irq);
	break;
	case 4:
	if (psc_present)
	psc_irq_disable(irq);
	break;
	case 8:
	if (baboon_present)
	baboon_irq_disable(irq);
	break;
	}
	}

	void mac_clear_irq(unsigned int irq)
	{
	switch(IRQ_SRC(irq)) {
	case 1:
	via_irq_clear(irq);
	break;
	case 2:
	case 7:
	if (oss_present)
	oss_irq_clear(irq);
	else
	via_irq_clear(irq);
	break;
	case 3:
	case 5:
	case 6:
	if (psc_present)
	psc_irq_clear(irq);
	else if (oss_present)
	oss_irq_clear(irq);
	break;
	case 4:
	if (psc_present)
	psc_irq_clear(irq);
	break;
	case 8:
	if (baboon_present)
	baboon_irq_clear(irq);
	break;
	}
	}

	int mac_irq_pending(unsigned int irq)
	{
	switch(IRQ_SRC(irq)) {
	case 1:
	return via_irq_pending(irq);
	case 2:
	case 7:
	if (oss_present)
	return oss_irq_pending(irq);
	else
	return via_irq_pending(irq);
	case 3:
	case 5:
	case 6:
	if (psc_present)
	return psc_irq_pending(irq);
	else if (oss_present)
	return oss_irq_pending(irq);
	break;
	case 4:
	if (psc_present)
	return psc_irq_pending(irq);
	break;
	}
	return 0;
	}
	EXPORT_SYMBOL(mac_irq_pending);

	static int num_debug[8];

	irqreturn_t mac_debug_handler(int irq, void *dev_id)
	{
	if (num_debug[irq] < 10) {
	printk("DEBUG: Unexpected IRQ %d\n", irq);
	num_debug[irq]++;
	}
	return IRQ_HANDLED;
	}

	static int in_nmi;
	static volatile int nmi_hold;

	irqreturn_t mac_nmi_handler(int irq, void *dev_id)
	{
	int i;
	/*
	* generate debug output on NMI switch if 'debug' kernel option given
	* (only works with Penguin!)
	*/

	in_nmi++;
	for (i=0; i<100; i++)
	udelay(1000);

	if (in_nmi == 1) {
	nmi_hold = 1;
	printk("... pausing, press NMI to resume ...");
	} else {
	printk(" ok!\n");
	nmi_hold = 0;
	}

	barrier();

	while (nmi_hold == 1)
	udelay(1000);

	if (console_loglevel >= 8) {
	#if 0
	struct pt_regs *fp = get_irq_regs();
	show_state();
	printk("PC: %08lx\nSR: %04x SP: %p\n", fp->pc, fp->sr, fp);
	printk("d0: %08lx d1: %08lx d2: %08lx d3: %08lx\n",
	fp->d0, fp->d1, fp->d2, fp->d3);
	printk("d4: %08lx d5: %08lx a0: %08lx a1: %08lx\n",
	fp->d4, fp->d5, fp->a0, fp->a1);

	if (STACK_MAGIC != (unsigned long )current->kernel_stack_page)
	printk("Corrupted stack page\n");
	printk("Process %s (pid: %d, stackpage=%08lx)\n",
	current->comm, current->pid, current->kernel_stack_page);
	if (intr_count == 1)
	dump_stack((struct frame *)fp);
	#else
	/* printk("NMI "); */
	#endif
	}
	in_nmi--;
	return IRQ_HANDLED;
	}