[net-next-2.6.git] / arch / i386 / kernel / i8259.c

#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/sysdev.h>
#include <linux/bitops.h>

#include <asm/8253pit.h>
#include <asm/atomic.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/timer.h>
#include <asm/pgtable.h>
#include <asm/delay.h>
#include <asm/desc.h>
#include <asm/apic.h>
#include <asm/arch_hooks.h>
#include <asm/i8259.h>

#include <io_ports.h>

/*
 * This is the 'legacy' 8259A Programmable Interrupt Controller,
 * present in the majority of PC/AT boxes.
 * plus some generic x86 specific things if generic specifics makes
 * any sense at all.
 * this file should become arch/i386/kernel/irq.c when the old irq.c
 * moves to arch independent land
 */

static int i8259A_auto_eoi;
DEFINE_SPINLOCK(i8259A_lock);
static void mask_and_ack_8259A(unsigned int);

static struct irq_chip i8259A_chip = {
	.name		= "XT-PIC",
	.mask		= disable_8259A_irq,
	.unmask		= enable_8259A_irq,
	.mask_ack	= mask_and_ack_8259A,
};

/*
 * 8259A PIC functions to handle ISA devices:
 */

/*
 * This contains the irq mask for both 8259A irq controllers,
 */
unsigned int cached_irq_mask = 0xffff;

/*
 * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
 * boards the timer interrupt is not really connected to any IO-APIC pin,
 * it's fed to the master 8259A's IR0 line only.
 *
 * Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
 * this 'mixed mode' IRQ handling costs nothing because it's only used
 * at IRQ setup time.
 */
unsigned long io_apic_irqs;

void disable_8259A_irq(unsigned int irq)
{
	unsigned int mask = 1 << irq;
	unsigned long flags;

	spin_lock_irqsave(&i8259A_lock, flags);
	cached_irq_mask |= mask;
	if (irq & 8)
		outb(cached_slave_mask, PIC_SLAVE_IMR);
	else
		outb(cached_master_mask, PIC_MASTER_IMR);
	spin_unlock_irqrestore(&i8259A_lock, flags);
}

void enable_8259A_irq(unsigned int irq)
{
	unsigned int mask = ~(1 << irq);
	unsigned long flags;

	spin_lock_irqsave(&i8259A_lock, flags);
	cached_irq_mask &= mask;
	if (irq & 8)
		outb(cached_slave_mask, PIC_SLAVE_IMR);
	else
		outb(cached_master_mask, PIC_MASTER_IMR);
	spin_unlock_irqrestore(&i8259A_lock, flags);
}

int i8259A_irq_pending(unsigned int irq)
{
	unsigned int mask = 1<<irq;
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&i8259A_lock, flags);
	if (irq < 8)
		ret = inb(PIC_MASTER_CMD) & mask;
	else
		ret = inb(PIC_SLAVE_CMD) & (mask >> 8);
	spin_unlock_irqrestore(&i8259A_lock, flags);

	return ret;
}

void make_8259A_irq(unsigned int irq)
{
	disable_irq_nosync(irq);
	io_apic_irqs &= ~(1<<irq);
	set_irq_chip_and_handler(irq, &i8259A_chip, handle_level_irq);
	enable_irq(irq);
}

/*
 * This function assumes to be called rarely. Switching between
 * 8259A registers is slow.
 * This has to be protected by the irq controller spinlock
 * before being called.
 */
static inline int i8259A_irq_real(unsigned int irq)
{
	int value;
	int irqmask = 1<<irq;

	if (irq < 8) {
		outb(0x0B,PIC_MASTER_CMD);	/* ISR register */
		value = inb(PIC_MASTER_CMD) & irqmask;
		outb(0x0A,PIC_MASTER_CMD);	/* back to the IRR register */
		return value;
	}
	outb(0x0B,PIC_SLAVE_CMD);	/* ISR register */
	value = inb(PIC_SLAVE_CMD) & (irqmask >> 8);
	outb(0x0A,PIC_SLAVE_CMD);	/* back to the IRR register */
	return value;
}

/*
 * Careful! The 8259A is a fragile beast, it pretty
 * much _has_ to be done exactly like this (mask it
 * first, _then_ send the EOI, and the order of EOI
 * to the two 8259s is important!
 */
static void mask_and_ack_8259A(unsigned int irq)
{
	unsigned int irqmask = 1 << irq;
	unsigned long flags;

	spin_lock_irqsave(&i8259A_lock, flags);
	/*
	 * Lightweight spurious IRQ detection. We do not want
	 * to overdo spurious IRQ handling - it's usually a sign
	 * of hardware problems, so we only do the checks we can
	 * do without slowing down good hardware unnecessarily.
	 *
	 * Note that IRQ7 and IRQ15 (the two spurious IRQs
	 * usually resulting from the 8259A-1|2 PICs) occur
	 * even if the IRQ is masked in the 8259A. Thus we
	 * can check spurious 8259A IRQs without doing the
	 * quite slow i8259A_irq_real() call for every IRQ.
	 * This does not cover 100% of spurious interrupts,
	 * but should be enough to warn the user that there
	 * is something bad going on ...
	 */
	if (cached_irq_mask & irqmask)
		goto spurious_8259A_irq;
	cached_irq_mask |= irqmask;

handle_real_irq:
	if (irq & 8) {
		inb(PIC_SLAVE_IMR);	/* DUMMY - (do we need this?) */
		outb(cached_slave_mask, PIC_SLAVE_IMR);
		outb(0x60+(irq&7),PIC_SLAVE_CMD);/* 'Specific EOI' to slave */
		outb(0x60+PIC_CASCADE_IR,PIC_MASTER_CMD); /* 'Specific EOI' to master-IRQ2 */
	} else {
		inb(PIC_MASTER_IMR);	/* DUMMY - (do we need this?) */
		outb(cached_master_mask, PIC_MASTER_IMR);
		outb(0x60+irq,PIC_MASTER_CMD);	/* 'Specific EOI to master */
	}
	spin_unlock_irqrestore(&i8259A_lock, flags);
	return;

spurious_8259A_irq:
	/*
	 * this is the slow path - should happen rarely.
	 */
	if (i8259A_irq_real(irq))
		/*
		 * oops, the IRQ _is_ in service according to the
		 * 8259A - not spurious, go handle it.
		 */
		goto handle_real_irq;

	{
		static int spurious_irq_mask;
		/*
		 * At this point we can be sure the IRQ is spurious,
		 * lets ACK and report it. [once per IRQ]
		 */
		if (!(spurious_irq_mask & irqmask)) {
			printk(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq);
			spurious_irq_mask |= irqmask;
		}
		atomic_inc(&irq_err_count);
		/*
		 * Theoretically we do not have to handle this IRQ,
		 * but in Linux this does not cause problems and is
		 * simpler for us.
		 */
		goto handle_real_irq;
	}
}

static char irq_trigger[2];
/**
 * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
 */
static void restore_ELCR(char *trigger)
{
	outb(trigger[0], 0x4d0);
	outb(trigger[1], 0x4d1);
}

static void save_ELCR(char *trigger)
{
	/* IRQ 0,1,2,8,13 are marked as reserved */
	trigger[0] = inb(0x4d0) & 0xF8;
	trigger[1] = inb(0x4d1) & 0xDE;
}

static int i8259A_resume(struct sys_device *dev)
{
	init_8259A(i8259A_auto_eoi);
	restore_ELCR(irq_trigger);
	return 0;
}

static int i8259A_suspend(struct sys_device *dev, pm_message_t state)
{
	save_ELCR(irq_trigger);
	return 0;
}

static int i8259A_shutdown(struct sys_device *dev)
{
	/* Put the i8259A into a quiescent state that
	 * the kernel initialization code can get it
	 * out of.
	 */
	outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */
	outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-1 */
	return 0;
}

static struct sysdev_class i8259_sysdev_class = {
	set_kset_name("i8259"),
	.suspend = i8259A_suspend,
	.resume = i8259A_resume,
	.shutdown = i8259A_shutdown,
};

static struct sys_device device_i8259A = {
	.id	= 0,
	.cls	= &i8259_sysdev_class,
};

static int __init i8259A_init_sysfs(void)
{
	int error = sysdev_class_register(&i8259_sysdev_class);
	if (!error)
		error = sysdev_register(&device_i8259A);
	return error;
}

device_initcall(i8259A_init_sysfs);

void init_8259A(int auto_eoi)
{
	unsigned long flags;

	i8259A_auto_eoi = auto_eoi;

	spin_lock_irqsave(&i8259A_lock, flags);

	outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */
	outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */

	/*
	 * outb_p - this has to work on a wide range of PC hardware.
	 */
	outb_p(0x11, PIC_MASTER_CMD);	/* ICW1: select 8259A-1 init */
	outb_p(0x20 + 0, PIC_MASTER_IMR);	/* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */
	outb_p(1U << PIC_CASCADE_IR, PIC_MASTER_IMR);	/* 8259A-1 (the master) has a slave on IR2 */
	if (auto_eoi)	/* master does Auto EOI */
		outb_p(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR);
	else		/* master expects normal EOI */
		outb_p(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR);

	outb_p(0x11, PIC_SLAVE_CMD);	/* ICW1: select 8259A-2 init */
	outb_p(0x20 + 8, PIC_SLAVE_IMR);	/* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */
	outb_p(PIC_CASCADE_IR, PIC_SLAVE_IMR);	/* 8259A-2 is a slave on master's IR2 */
	outb_p(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR); /* (slave's support for AEOI in flat mode is to be investigated) */
	if (auto_eoi)
		/*
		 * In AEOI mode we just have to mask the interrupt
		 * when acking.
		 */
		i8259A_chip.mask_ack = disable_8259A_irq;
	else
		i8259A_chip.mask_ack = mask_and_ack_8259A;

	udelay(100);		/* wait for 8259A to initialize */

	outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
	outb(cached_slave_mask, PIC_SLAVE_IMR);	  /* restore slave IRQ mask */

	spin_unlock_irqrestore(&i8259A_lock, flags);
}

/*
 * Note that on a 486, we don't want to do a SIGFPE on an irq13
 * as the irq is unreliable, and exception 16 works correctly
 * (ie as explained in the intel literature). On a 386, you
 * can't use exception 16 due to bad IBM design, so we have to
 * rely on the less exact irq13.
 *
 * Careful.. Not only is IRQ13 unreliable, but it is also
 * leads to races. IBM designers who came up with it should
 * be shot.
 */
 

static irqreturn_t math_error_irq(int cpl, void *dev_id)
{
	extern void math_error(void __user *);
	outb(0,0xF0);
	if (ignore_fpu_irq || !boot_cpu_data.hard_math)
		return IRQ_NONE;
	math_error((void __user *)get_irq_regs()->eip);
	return IRQ_HANDLED;
}

/*
 * New motherboards sometimes make IRQ 13 be a PCI interrupt,
 * so allow interrupt sharing.
 */
static struct irqaction fpu_irq = { math_error_irq, 0, CPU_MASK_NONE, "fpu", NULL, NULL };

void __init init_ISA_irqs (void)
{
	int i;

#ifdef CONFIG_X86_LOCAL_APIC
	init_bsp_APIC();
#endif
	init_8259A(0);

	for (i = 0; i < NR_IRQS; i++) {
		irq_desc[i].status = IRQ_DISABLED;
		irq_desc[i].action = NULL;
		irq_desc[i].depth = 1;

		if (i < 16) {
			/*
			 * 16 old-style INTA-cycle interrupts:
			 */
			set_irq_chip_and_handler(i, &i8259A_chip,
						 handle_level_irq);
		} else {
			/*
			 * 'high' PCI IRQs filled in on demand
			 */
			irq_desc[i].chip = &no_irq_chip;
		}
	}
}

void __init init_IRQ(void)
{
	int i;

	/* all the set up before the call gates are initialised */
	pre_intr_init_hook();

	/*
	 * Cover the whole vector space, no vector can escape
	 * us. (some of these will be overridden and become
	 * 'special' SMP interrupts)
	 */
	for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
		int vector = FIRST_EXTERNAL_VECTOR + i;
		if (i >= NR_IRQS)
			break;
		if (vector != SYSCALL_VECTOR) 
			set_intr_gate(vector, interrupt[i]);
	}

	/* setup after call gates are initialised (usually add in
	 * the architecture specific gates)
	 */
	intr_init_hook();

	/*
	 * Set the clock to HZ Hz, we already have a valid
	 * vector now:
	 */
	setup_pit_timer();

	/*
	 * External FPU? Set up irq13 if so, for
	 * original braindamaged IBM FERR coupling.
	 */
	if (boot_cpu_data.hard_math && !cpu_has_fpu)
		setup_irq(FPU_IRQ, &fpu_irq);

	irq_ctx_init(smp_processor_id());
}
Commit	Line	Data
1da177e4 LT	1	#include <linux/errno.h>
	2	#include <linux/signal.h>
	3	#include <linux/sched.h>
	4	#include <linux/ioport.h>
	5	#include <linux/interrupt.h>
	6	#include <linux/slab.h>
	7	#include <linux/random.h>
	8	#include <linux/smp_lock.h>
	9	#include <linux/init.h>
	10	#include <linux/kernel_stat.h>
	11	#include <linux/sysdev.h>
	12	#include <linux/bitops.h>
	13
	14	#include <asm/8253pit.h>
	15	#include <asm/atomic.h>
	16	#include <asm/system.h>
	17	#include <asm/io.h>
1da177e4 LT	18	#include <asm/timer.h>
	19	#include <asm/pgtable.h>
	20	#include <asm/delay.h>
	21	#include <asm/desc.h>
	22	#include <asm/apic.h>
	23	#include <asm/arch_hooks.h>
	24	#include <asm/i8259.h>
	25
1da177e4 LT	26	#include <io_ports.h>
	27
	28	/*
	29	* This is the 'legacy' 8259A Programmable Interrupt Controller,
	30	* present in the majority of PC/AT boxes.
	31	* plus some generic x86 specific things if generic specifics makes
	32	* any sense at all.
	33	* this file should become arch/i386/kernel/irq.c when the old irq.c
	34	* moves to arch independent land
	35	*/
	36
35d534a3	37	static int i8259A_auto_eoi;
f5b9ed7a	38	DEFINE_SPINLOCK(i8259A_lock);
1da177e4 LT	39	static void mask_and_ack_8259A(unsigned int);
1da177e4 LT	40
f5b9ed7a IM	41	static struct irq_chip i8259A_chip = {
	42	.name = "XT-PIC",
	43	.mask = disable_8259A_irq,
	44	.unmask = enable_8259A_irq,
	45	.mask_ack = mask_and_ack_8259A,
1da177e4 LT	46	};
	47
	48	/*
	49	* 8259A PIC functions to handle ISA devices:
	50	*/
	51
	52	/*
	53	* This contains the irq mask for both 8259A irq controllers,
	54	*/
	55	unsigned int cached_irq_mask = 0xffff;
	56
	57	/*
	58	* Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
	59	* boards the timer interrupt is not really connected to any IO-APIC pin,
	60	* it's fed to the master 8259A's IR0 line only.
	61	*
	62	* Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
	63	* this 'mixed mode' IRQ handling costs nothing because it's only used
	64	* at IRQ setup time.
	65	*/
	66	unsigned long io_apic_irqs;
	67
	68	void disable_8259A_irq(unsigned int irq)
	69	{
	70	unsigned int mask = 1 << irq;
	71	unsigned long flags;
	72
	73	spin_lock_irqsave(&i8259A_lock, flags);
	74	cached_irq_mask \|= mask;
	75	if (irq & 8)
	76	outb(cached_slave_mask, PIC_SLAVE_IMR);
	77	else
	78	outb(cached_master_mask, PIC_MASTER_IMR);
	79	spin_unlock_irqrestore(&i8259A_lock, flags);
	80	}
	81
	82	void enable_8259A_irq(unsigned int irq)
	83	{
	84	unsigned int mask = ~(1 << irq);
	85	unsigned long flags;
	86
	87	spin_lock_irqsave(&i8259A_lock, flags);
	88	cached_irq_mask &= mask;
	89	if (irq & 8)
	90	outb(cached_slave_mask, PIC_SLAVE_IMR);
	91	else
	92	outb(cached_master_mask, PIC_MASTER_IMR);
	93	spin_unlock_irqrestore(&i8259A_lock, flags);
	94	}
	95
	96	int i8259A_irq_pending(unsigned int irq)
	97	{
	98	unsigned int mask = 1<<irq;
	99	unsigned long flags;
	100	int ret;
	101
	102	spin_lock_irqsave(&i8259A_lock, flags);
	103	if (irq < 8)
	104	ret = inb(PIC_MASTER_CMD) & mask;
	105	else
	106	ret = inb(PIC_SLAVE_CMD) & (mask >> 8);
	107	spin_unlock_irqrestore(&i8259A_lock, flags);
	108
	109	return ret;
110	}
111
112	void make_8259A_irq(unsigned int irq)
113	{
114	disable_irq_nosync(irq);
115	io_apic_irqs &= ~(1<<irq);
f5b9ed7a	116	set_irq_chip_and_handler(irq, &i8259A_chip, handle_level_irq);
1da177e4 LT	117	enable_irq(irq);
	118	}
	119
	120	/*
	121	* This function assumes to be called rarely. Switching between
	122	* 8259A registers is slow.
	123	* This has to be protected by the irq controller spinlock
	124	* before being called.
	125	*/
	126	static inline int i8259A_irq_real(unsigned int irq)
	127	{
	128	int value;
	129	int irqmask = 1<<irq;
	130
	131	if (irq < 8) {
	132	outb(0x0B,PIC_MASTER_CMD); /* ISR register */
	133	value = inb(PIC_MASTER_CMD) & irqmask;
	134	outb(0x0A,PIC_MASTER_CMD); /* back to the IRR register */
	135	return value;
	136	}
	137	outb(0x0B,PIC_SLAVE_CMD); /* ISR register */
	138	value = inb(PIC_SLAVE_CMD) & (irqmask >> 8);
	139	outb(0x0A,PIC_SLAVE_CMD); /* back to the IRR register */
	140	return value;
	141	}
	142
	143	/*
	144	* Careful! The 8259A is a fragile beast, it pretty
	145	* much _has_ to be done exactly like this (mask it
	146	* first, _then_ send the EOI, and the order of EOI
	147	* to the two 8259s is important!
	148	*/
	149	static void mask_and_ack_8259A(unsigned int irq)
	150	{
	151	unsigned int irqmask = 1 << irq;
	152	unsigned long flags;
	153
	154	spin_lock_irqsave(&i8259A_lock, flags);
	155	/*
	156	* Lightweight spurious IRQ detection. We do not want
	157	* to overdo spurious IRQ handling - it's usually a sign
	158	* of hardware problems, so we only do the checks we can
d6e05edc	159	* do without slowing down good hardware unnecessarily.
1da177e4 LT	160	*
	161	* Note that IRQ7 and IRQ15 (the two spurious IRQs
	162	* usually resulting from the 8259A-1\|2 PICs) occur
	163	* even if the IRQ is masked in the 8259A. Thus we
	164	* can check spurious 8259A IRQs without doing the
	165	* quite slow i8259A_irq_real() call for every IRQ.
	166	* This does not cover 100% of spurious interrupts,
	167	* but should be enough to warn the user that there
	168	* is something bad going on ...
	169	*/
	170	if (cached_irq_mask & irqmask)
	171	goto spurious_8259A_irq;
	172	cached_irq_mask \|= irqmask;
	173
	174	handle_real_irq:
	175	if (irq & 8) {
	176	inb(PIC_SLAVE_IMR); /* DUMMY - (do we need this?) */
	177	outb(cached_slave_mask, PIC_SLAVE_IMR);
	178	outb(0x60+(irq&7),PIC_SLAVE_CMD);/* 'Specific EOI' to slave */
	179	outb(0x60+PIC_CASCADE_IR,PIC_MASTER_CMD); /* 'Specific EOI' to master-IRQ2 */
	180	} else {
	181	inb(PIC_MASTER_IMR); /* DUMMY - (do we need this?) */
	182	outb(cached_master_mask, PIC_MASTER_IMR);
	183	outb(0x60+irq,PIC_MASTER_CMD); /* 'Specific EOI to master */
	184	}
	185	spin_unlock_irqrestore(&i8259A_lock, flags);
	186	return;
	187
	188	spurious_8259A_irq:
	189	/*
	190	* this is the slow path - should happen rarely.
	191	*/
	192	if (i8259A_irq_real(irq))
	193	/*
	194	* oops, the IRQ _is_ in service according to the
	195	* 8259A - not spurious, go handle it.
	196	*/
	197	goto handle_real_irq;
	198
	199	{
	200	static int spurious_irq_mask;
	201	/*
	202	* At this point we can be sure the IRQ is spurious,
	203	* lets ACK and report it. [once per IRQ]
	204	*/
	205	if (!(spurious_irq_mask & irqmask)) {
	206	printk(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq);
	207	spurious_irq_mask \|= irqmask;
	208	}
	209	atomic_inc(&irq_err_count);
	210	/*
	211	* Theoretically we do not have to handle this IRQ,
	212	* but in Linux this does not cause problems and is
	213	* simpler for us.
	214	*/
	215	goto handle_real_irq;
	216	}
	217	}
	218
	219	static char irq_trigger[2];
	220	/**
	221	* ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
	222	*/
	223	static void restore_ELCR(char *trigger)
224	{
225	outb(trigger[0], 0x4d0);
226	outb(trigger[1], 0x4d1);
227	}
228
229	static void save_ELCR(char *trigger)
230	{
231	/* IRQ 0,1,2,8,13 are marked as reserved */
232	trigger[0] = inb(0x4d0) & 0xF8;
233	trigger[1] = inb(0x4d1) & 0xDE;
234	}
235
236	static int i8259A_resume(struct sys_device *dev)
237	{
35d534a3	238	init_8259A(i8259A_auto_eoi);
1da177e4 LT	239	restore_ELCR(irq_trigger);
	240	return 0;
	241	}
	242
438510f6	243	static int i8259A_suspend(struct sys_device *dev, pm_message_t state)
1da177e4 LT	244	{
	245	save_ELCR(irq_trigger);
	246	return 0;
	247	}
	248
cee5dab4 EB	249	static int i8259A_shutdown(struct sys_device *dev)
	250	{
	251	/* Put the i8259A into a quiescent state that
	252	* the kernel initialization code can get it
	253	* out of.
	254	*/
110cb1d2 AM	255	outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
110cb1d2 AM	256	outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-1 */
cee5dab4 EB	257	return 0;
	258	}
	259
1da177e4 LT	260	static struct sysdev_class i8259_sysdev_class = {
	261	set_kset_name("i8259"),
	262	.suspend = i8259A_suspend,
	263	.resume = i8259A_resume,
cee5dab4	264	.shutdown = i8259A_shutdown,
1da177e4 LT	265	};
	266
	267	static struct sys_device device_i8259A = {
	268	.id = 0,
	269	.cls = &i8259_sysdev_class,
	270	};
	271
	272	static int __init i8259A_init_sysfs(void)
	273	{
	274	int error = sysdev_class_register(&i8259_sysdev_class);
	275	if (!error)
	276	error = sysdev_register(&device_i8259A);
	277	return error;
	278	}
	279
	280	device_initcall(i8259A_init_sysfs);
	281
	282	void init_8259A(int auto_eoi)
	283	{
	284	unsigned long flags;
	285
35d534a3 MG	286	i8259A_auto_eoi = auto_eoi;
35d534a3 MG	287
1da177e4 LT	288	spin_lock_irqsave(&i8259A_lock, flags);
	289
	290	outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
	291	outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */
	292
	293	/*
	294	* outb_p - this has to work on a wide range of PC hardware.
	295	*/
	296	outb_p(0x11, PIC_MASTER_CMD); /* ICW1: select 8259A-1 init */
	297	outb_p(0x20 + 0, PIC_MASTER_IMR); /* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */
	298	outb_p(1U << PIC_CASCADE_IR, PIC_MASTER_IMR); /* 8259A-1 (the master) has a slave on IR2 */
	299	if (auto_eoi) /* master does Auto EOI */
	300	outb_p(MASTER_ICW4_DEFAULT \| PIC_ICW4_AEOI, PIC_MASTER_IMR);
	301	else /* master expects normal EOI */
	302	outb_p(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR);
	303
	304	outb_p(0x11, PIC_SLAVE_CMD); /* ICW1: select 8259A-2 init */
	305	outb_p(0x20 + 8, PIC_SLAVE_IMR); /* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */
	306	outb_p(PIC_CASCADE_IR, PIC_SLAVE_IMR); /* 8259A-2 is a slave on master's IR2 */
	307	outb_p(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR); /* (slave's support for AEOI in flat mode is to be investigated) */
	308	if (auto_eoi)
	309	/*
f5b9ed7a	310	* In AEOI mode we just have to mask the interrupt
1da177e4 LT	311	* when acking.
1da177e4 LT	312	*/
f5b9ed7a	313	i8259A_chip.mask_ack = disable_8259A_irq;
1da177e4	314	else
f5b9ed7a	315	i8259A_chip.mask_ack = mask_and_ack_8259A;
1da177e4 LT	316
	317	udelay(100); /* wait for 8259A to initialize */
	318
	319	outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
	320	outb(cached_slave_mask, PIC_SLAVE_IMR); /* restore slave IRQ mask */
	321
	322	spin_unlock_irqrestore(&i8259A_lock, flags);
	323	}
	324
	325	/*
	326	* Note that on a 486, we don't want to do a SIGFPE on an irq13
	327	* as the irq is unreliable, and exception 16 works correctly
	328	* (ie as explained in the intel literature). On a 386, you
	329	* can't use exception 16 due to bad IBM design, so we have to
	330	* rely on the less exact irq13.
	331	*
	332	* Careful.. Not only is IRQ13 unreliable, but it is also
	333	* leads to races. IBM designers who came up with it should
	334	* be shot.
	335	*/
	336
	337
7d12e780	338	static irqreturn_t math_error_irq(int cpl, void *dev_id)
1da177e4 LT	339	{
	340	extern void math_error(void __user *);
	341	outb(0,0xF0);
	342	if (ignore_fpu_irq \|\| !boot_cpu_data.hard_math)
	343	return IRQ_NONE;
7d12e780	344	math_error((void __user *)get_irq_regs()->eip);
1da177e4 LT	345	return IRQ_HANDLED;
	346	}
	347
	348	/*
	349	* New motherboards sometimes make IRQ 13 be a PCI interrupt,
	350	* so allow interrupt sharing.
	351	*/
	352	static struct irqaction fpu_irq = { math_error_irq, 0, CPU_MASK_NONE, "fpu", NULL, NULL };
	353
	354	void __init init_ISA_irqs (void)
	355	{
	356	int i;
	357
	358	#ifdef CONFIG_X86_LOCAL_APIC
	359	init_bsp_APIC();
	360	#endif
	361	init_8259A(0);
	362
	363	for (i = 0; i < NR_IRQS; i++) {
	364	irq_desc[i].status = IRQ_DISABLED;
	365	irq_desc[i].action = NULL;
	366	irq_desc[i].depth = 1;
	367
	368	if (i < 16) {
	369	/*
	370	* 16 old-style INTA-cycle interrupts:
	371	*/
f5b9ed7a IM	372	set_irq_chip_and_handler(i, &i8259A_chip,
f5b9ed7a IM	373	handle_level_irq);
1da177e4 LT	374	} else {
	375	/*
	376	* 'high' PCI IRQs filled in on demand
	377	*/
f5b9ed7a	378	irq_desc[i].chip = &no_irq_chip;
1da177e4 LT	379	}
	380	}
	381	}
	382
	383	void __init init_IRQ(void)
	384	{
	385	int i;
	386
	387	/* all the set up before the call gates are initialised */
	388	pre_intr_init_hook();
	389
	390	/*
	391	* Cover the whole vector space, no vector can escape
	392	* us. (some of these will be overridden and become
	393	* 'special' SMP interrupts)
	394	*/
	395	for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
	396	int vector = FIRST_EXTERNAL_VECTOR + i;
	397	if (i >= NR_IRQS)
	398	break;
	399	if (vector != SYSCALL_VECTOR)
	400	set_intr_gate(vector, interrupt[i]);
	401	}
	402
	403	/* setup after call gates are initialised (usually add in
	404	* the architecture specific gates)
	405	*/
	406	intr_init_hook();
	407
	408	/*
	409	* Set the clock to HZ Hz, we already have a valid
	410	* vector now:
	411	*/
	412	setup_pit_timer();
	413
	414	/*
	415	* External FPU? Set up irq13 if so, for
	416	* original braindamaged IBM FERR coupling.
	417	*/
	418	if (boot_cpu_data.hard_math && !cpu_has_fpu)
	419	setup_irq(FPU_IRQ, &fpu_irq);
	420
	421	irq_ctx_init(smp_processor_id());
	422	}