[deliverable/linux.git] / arch / parisc / kernel / irq.c

/* 
 * Code to handle x86 style IRQs plus some generic interrupt stuff.
 *
 * Copyright (C) 1992 Linus Torvalds
 * Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle
 * Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
 * Copyright (C) 1999-2000 Grant Grundler
 * Copyright (c) 2005 Matthew Wilcox
 *
 *    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, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <asm/io.h>

#include <asm/smp.h>

#undef PARISC_IRQ_CR16_COUNTS

extern irqreturn_t timer_interrupt(int, void *);
extern irqreturn_t ipi_interrupt(int, void *);

#define EIEM_MASK(irq)       (1UL<<(CPU_IRQ_MAX - irq))

/* Bits in EIEM correlate with cpu_irq_action[].
** Numbered *Big Endian*! (ie bit 0 is MSB)
*/
static volatile unsigned long cpu_eiem = 0;

/*
** ack bitmap ... habitually set to 1, but reset to zero
** between ->ack() and ->end() of the interrupt to prevent
** re-interruption of a processing interrupt.
*/
static volatile unsigned long global_ack_eiem = ~0UL;
/*
** Local bitmap, same as above but for per-cpu interrupts
*/
static DEFINE_PER_CPU(unsigned long, local_ack_eiem) = ~0UL;

static void cpu_disable_irq(unsigned int irq)
{
	unsigned long eirr_bit = EIEM_MASK(irq);

	cpu_eiem &= ~eirr_bit;
	/* Do nothing on the other CPUs.  If they get this interrupt,
	 * The & cpu_eiem in the do_cpu_irq_mask() ensures they won't
	 * handle it, and the set_eiem() at the bottom will ensure it
	 * then gets disabled */
}

static void cpu_enable_irq(unsigned int irq)
{
	unsigned long eirr_bit = EIEM_MASK(irq);

	cpu_eiem |= eirr_bit;

	/* This is just a simple NOP IPI.  But what it does is cause
	 * all the other CPUs to do a set_eiem(cpu_eiem) at the end
	 * of the interrupt handler */
	smp_send_all_nop();
}

static unsigned int cpu_startup_irq(unsigned int irq)
{
	cpu_enable_irq(irq);
	return 0;
}

void no_ack_irq(unsigned int irq) { }
void no_end_irq(unsigned int irq) { }

void cpu_ack_irq(unsigned int irq)
{
	unsigned long mask = EIEM_MASK(irq);
	int cpu = smp_processor_id();

	/* Clear in EIEM so we can no longer process */
	if (CHECK_IRQ_PER_CPU(irq_desc[irq].status))
		per_cpu(local_ack_eiem, cpu) &= ~mask;
	else
		global_ack_eiem &= ~mask;

	/* disable the interrupt */
	set_eiem(cpu_eiem & global_ack_eiem & per_cpu(local_ack_eiem, cpu));
	/* and now ack it */
	mtctl(mask, 23);
}

void cpu_end_irq(unsigned int irq)
{
	unsigned long mask = EIEM_MASK(irq);
	int cpu = smp_processor_id();

	/* set it in the eiems---it's no longer in process */
	if (CHECK_IRQ_PER_CPU(irq_desc[irq].status))
		per_cpu(local_ack_eiem, cpu) |= mask;
	else
		global_ack_eiem |= mask;

	/* enable the interrupt */
	set_eiem(cpu_eiem & global_ack_eiem & per_cpu(local_ack_eiem, cpu));
}

#ifdef CONFIG_SMP
int cpu_check_affinity(unsigned int irq, cpumask_t *dest)
{
	int cpu_dest;

	/* timer and ipi have to always be received on all CPUs */
	if (CHECK_IRQ_PER_CPU(irq)) {
		/* Bad linux design decision.  The mask has already
		 * been set; we must reset it */
		irq_desc[irq].affinity = CPU_MASK_ALL;
		return -EINVAL;
	}

	/* whatever mask they set, we just allow one CPU */
	cpu_dest = first_cpu(*dest);
	*dest = cpumask_of_cpu(cpu_dest);

	return 0;
}

static void cpu_set_affinity_irq(unsigned int irq, cpumask_t dest)
{
	if (cpu_check_affinity(irq, &dest))
		return;

	irq_desc[irq].affinity = dest;
}
#endif

static struct hw_interrupt_type cpu_interrupt_type = {
	.typename	= "CPU",
	.startup	= cpu_startup_irq,
	.shutdown	= cpu_disable_irq,
	.enable		= cpu_enable_irq,
	.disable	= cpu_disable_irq,
	.ack		= cpu_ack_irq,
	.end		= cpu_end_irq,
#ifdef CONFIG_SMP
	.set_affinity	= cpu_set_affinity_irq,
#endif
	/* XXX: Needs to be written.  We managed without it so far, but
	 * we really ought to write it.
	 */
	.retrigger	= NULL,
};

int show_interrupts(struct seq_file *p, void *v)
{
	int i = *(loff_t *) v, j;
	unsigned long flags;

	if (i == 0) {
		seq_puts(p, "    ");
		for_each_online_cpu(j)
			seq_printf(p, "       CPU%d", j);

#ifdef PARISC_IRQ_CR16_COUNTS
		seq_printf(p, " [min/avg/max] (CPU cycle counts)");
#endif
		seq_putc(p, '\n');
	}

	if (i < NR_IRQS) {
		struct irqaction *action;

		spin_lock_irqsave(&irq_desc[i].lock, flags);
		action = irq_desc[i].action;
		if (!action)
			goto skip;
		seq_printf(p, "%3d: ", i);
#ifdef CONFIG_SMP
		for_each_online_cpu(j)
			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#else
		seq_printf(p, "%10u ", kstat_irqs(i));
#endif

		seq_printf(p, " %14s", irq_desc[i].chip->typename);
#ifndef PARISC_IRQ_CR16_COUNTS
		seq_printf(p, "  %s", action->name);

		while ((action = action->next))
			seq_printf(p, ", %s", action->name);
#else
		for ( ;action; action = action->next) {
			unsigned int k, avg, min, max;

			min = max = action->cr16_hist[0];

			for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) {
				int hist = action->cr16_hist[k];

				if (hist) {
					avg += hist;
				} else
					break;

				if (hist > max) max = hist;
				if (hist < min) min = hist;
			}

			avg /= k;
			seq_printf(p, " %s[%d/%d/%d]", action->name,
					min,avg,max);
		}
#endif

		seq_putc(p, '\n');
 skip:
		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
	}

	return 0;
}


/*
** The following form a "set": Virtual IRQ, Transaction Address, Trans Data.
** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit.
**
** To use txn_XXX() interfaces, get a Virtual IRQ first.
** Then use that to get the Transaction address and data.
*/

int cpu_claim_irq(unsigned int irq, struct irq_chip *type, void *data)
{
	if (irq_desc[irq].action)
		return -EBUSY;
	if (irq_desc[irq].chip != &cpu_interrupt_type)
		return -EBUSY;

	if (type) {
		irq_desc[irq].chip = type;
		irq_desc[irq].chip_data = data;
		cpu_interrupt_type.enable(irq);
	}
	return 0;
}

int txn_claim_irq(int irq)
{
	return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
}

/*
 * The bits_wide parameter accommodates the limitations of the HW/SW which
 * use these bits:
 * Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register)
 * V-class (EPIC):          6 bits
 * N/L/A-class (iosapic):   8 bits
 * PCI 2.2 MSI:            16 bits
 * Some PCI devices:       32 bits (Symbios SCSI/ATM/HyperFabric)
 *
 * On the service provider side:
 * o PA 1.1 (and PA2.0 narrow mode)     5-bits (width of EIR register)
 * o PA 2.0 wide mode                   6-bits (per processor)
 * o IA64                               8-bits (0-256 total)
 *
 * So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported
 * by the processor...and the N/L-class I/O subsystem supports more bits than
 * PA2.0 has. The first case is the problem.
 */
int txn_alloc_irq(unsigned int bits_wide)
{
	int irq;

	/* never return irq 0 cause that's the interval timer */
	for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) {
		if (cpu_claim_irq(irq, NULL, NULL) < 0)
			continue;
		if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide))
			continue;
		return irq;
	}

	/* unlikely, but be prepared */
	return -1;
}


unsigned long txn_affinity_addr(unsigned int irq, int cpu)
{
#ifdef CONFIG_SMP
	irq_desc[irq].affinity = cpumask_of_cpu(cpu);
#endif

	return cpu_data[cpu].txn_addr;
}


unsigned long txn_alloc_addr(unsigned int virt_irq)
{
	static int next_cpu = -1;

	next_cpu++; /* assign to "next" CPU we want this bugger on */

	/* validate entry */
	while ((next_cpu < NR_CPUS) && (!cpu_data[next_cpu].txn_addr || 
		!cpu_online(next_cpu)))
		next_cpu++;

	if (next_cpu >= NR_CPUS) 
		next_cpu = 0;	/* nothing else, assign monarch */

	return txn_affinity_addr(virt_irq, next_cpu);
}


unsigned int txn_alloc_data(unsigned int virt_irq)
{
	return virt_irq - CPU_IRQ_BASE;
}

static inline int eirr_to_irq(unsigned long eirr)
{
	int bit = fls_long(eirr);
	return (BITS_PER_LONG - bit) + TIMER_IRQ;
}

/* ONLY called from entry.S:intr_extint() */
void do_cpu_irq_mask(struct pt_regs *regs)
{
	struct pt_regs *old_regs;
	unsigned long eirr_val;
	int irq, cpu = smp_processor_id();
#ifdef CONFIG_SMP
	cpumask_t dest;
#endif

	old_regs = set_irq_regs(regs);
	local_irq_disable();
	irq_enter();

	eirr_val = mfctl(23) & cpu_eiem & global_ack_eiem &
		per_cpu(local_ack_eiem, cpu);
	if (!eirr_val)
		goto set_out;
	irq = eirr_to_irq(eirr_val);

#ifdef CONFIG_SMP
	dest = irq_desc[irq].affinity;
	if (CHECK_IRQ_PER_CPU(irq_desc[irq].status) &&
	    !cpu_isset(smp_processor_id(), dest)) {
		int cpu = first_cpu(dest);

		printk(KERN_DEBUG "redirecting irq %d from CPU %d to %d\n",
		       irq, smp_processor_id(), cpu);
		gsc_writel(irq + CPU_IRQ_BASE,
			   cpu_data[cpu].hpa);
		goto set_out;
	}
#endif
	__do_IRQ(irq);

 out:
	irq_exit();
	set_irq_regs(old_regs);
	return;

 set_out:
	set_eiem(cpu_eiem & global_ack_eiem & per_cpu(local_ack_eiem, cpu));
	goto out;
}

static struct irqaction timer_action = {
	.handler = timer_interrupt,
	.name = "timer",
	.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL,
};

#ifdef CONFIG_SMP
static struct irqaction ipi_action = {
	.handler = ipi_interrupt,
	.name = "IPI",
	.flags = IRQF_DISABLED | IRQF_PERCPU,
};
#endif

static void claim_cpu_irqs(void)
{
	int i;
	for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
		irq_desc[i].chip = &cpu_interrupt_type;
	}

	irq_desc[TIMER_IRQ].action = &timer_action;
	irq_desc[TIMER_IRQ].status |= IRQ_PER_CPU;
#ifdef CONFIG_SMP
	irq_desc[IPI_IRQ].action = &ipi_action;
	irq_desc[IPI_IRQ].status = IRQ_PER_CPU;
#endif
}

void __init init_IRQ(void)
{
	local_irq_disable();	/* PARANOID - should already be disabled */
	mtctl(~0UL, 23);	/* EIRR : clear all pending external intr */
	claim_cpu_irqs();
#ifdef CONFIG_SMP
	if (!cpu_eiem)
		cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
#else
	cpu_eiem = EIEM_MASK(TIMER_IRQ);
#endif
        set_eiem(cpu_eiem);	/* EIEM : enable all external intr */

}

void ack_bad_irq(unsigned int irq)
{
	printk("unexpected IRQ %d\n", irq);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Code to handle x86 style IRQs plus some generic interrupt stuff.
	3	*
	4	* Copyright (C) 1992 Linus Torvalds
	5	* Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle
	6	* Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
	7	* Copyright (C) 1999-2000 Grant Grundler
	8	* Copyright (c) 2005 Matthew Wilcox
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; either version 2, or (at your option)
	13	* any later version.
	14	*
	15	* This program is distributed in the hope that it will be useful,
	16	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	* GNU General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with this program; if not, write to the Free Software
	22	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	23	*/
	24	#include <linux/bitops.h>
1da177e4 LT	25	#include <linux/errno.h>
	26	#include <linux/init.h>
	27	#include <linux/interrupt.h>
	28	#include <linux/kernel_stat.h>
	29	#include <linux/seq_file.h>
	30	#include <linux/spinlock.h>
	31	#include <linux/types.h>
c2ab64d0	32	#include <asm/io.h>
1da177e4	33
1d4c452a KM	34	#include <asm/smp.h>
1d4c452a KM	35
1da177e4 LT	36	#undef PARISC_IRQ_CR16_COUNTS
1da177e4 LT	37
be577a52 MW	38	extern irqreturn_t timer_interrupt(int, void *);
be577a52 MW	39	extern irqreturn_t ipi_interrupt(int, void *);
1da177e4 LT	40
	41	#define EIEM_MASK(irq) (1UL<<(CPU_IRQ_MAX - irq))
	42
	43	/* Bits in EIEM correlate with cpu_irq_action[].
	44	** Numbered Big Endian! (ie bit 0 is MSB)
	45	*/
	46	static volatile unsigned long cpu_eiem = 0;
	47
7085689e JB	48	/*
	49	** ack bitmap ... habitually set to 1, but reset to zero
	50	** between ->ack() and ->end() of the interrupt to prevent
	51	** re-interruption of a processing interrupt.
	52	*/
	53	static volatile unsigned long global_ack_eiem = ~0UL;
	54	/*
	55	** Local bitmap, same as above but for per-cpu interrupts
	56	*/
	57	static DEFINE_PER_CPU(unsigned long, local_ack_eiem) = ~0UL;
	58
d911aed8	59	static void cpu_disable_irq(unsigned int irq)
1da177e4 LT	60	{
	61	unsigned long eirr_bit = EIEM_MASK(irq);
	62
	63	cpu_eiem &= ~eirr_bit;
d911aed8 JB	64	/* Do nothing on the other CPUs. If they get this interrupt,
	65	* The & cpu_eiem in the do_cpu_irq_mask() ensures they won't
	66	* handle it, and the set_eiem() at the bottom will ensure it
	67	* then gets disabled */
1da177e4 LT	68	}
	69
	70	static void cpu_enable_irq(unsigned int irq)
	71	{
	72	unsigned long eirr_bit = EIEM_MASK(irq);
	73
1da177e4	74	cpu_eiem \|= eirr_bit;
d911aed8	75
d911aed8 JB	76	/* This is just a simple NOP IPI. But what it does is cause
	77	* all the other CPUs to do a set_eiem(cpu_eiem) at the end
	78	* of the interrupt handler */
	79	smp_send_all_nop();
1da177e4 LT	80	}
	81
	82	static unsigned int cpu_startup_irq(unsigned int irq)
	83	{
	84	cpu_enable_irq(irq);
	85	return 0;
	86	}
	87
	88	void no_ack_irq(unsigned int irq) { }
	89	void no_end_irq(unsigned int irq) { }
	90
7085689e JB	91	void cpu_ack_irq(unsigned int irq)
	92	{
	93	unsigned long mask = EIEM_MASK(irq);
	94	int cpu = smp_processor_id();
	95
	96	/* Clear in EIEM so we can no longer process */
	97	if (CHECK_IRQ_PER_CPU(irq_desc[irq].status))
	98	per_cpu(local_ack_eiem, cpu) &= ~mask;
	99	else
	100	global_ack_eiem &= ~mask;
	101
	102	/* disable the interrupt */
	103	set_eiem(cpu_eiem & global_ack_eiem & per_cpu(local_ack_eiem, cpu));
	104	/* and now ack it */
	105	mtctl(mask, 23);
	106	}
	107
	108	void cpu_end_irq(unsigned int irq)
	109	{
	110	unsigned long mask = EIEM_MASK(irq);
	111	int cpu = smp_processor_id();
	112
	113	/* set it in the eiems---it's no longer in process */
	114	if (CHECK_IRQ_PER_CPU(irq_desc[irq].status))
	115	per_cpu(local_ack_eiem, cpu) \|= mask;
	116	else
	117	global_ack_eiem \|= mask;
	118
	119	/* enable the interrupt */
	120	set_eiem(cpu_eiem & global_ack_eiem & per_cpu(local_ack_eiem, cpu));
	121	}
	122
c2ab64d0 JB	123	#ifdef CONFIG_SMP
	124	int cpu_check_affinity(unsigned int irq, cpumask_t *dest)
	125	{
	126	int cpu_dest;
	127
	128	/* timer and ipi have to always be received on all CPUs */
7085689e	129	if (CHECK_IRQ_PER_CPU(irq)) {
c2ab64d0 JB	130	/* Bad linux design decision. The mask has already
c2ab64d0 JB	131	* been set; we must reset it */
a53da52f	132	irq_desc[irq].affinity = CPU_MASK_ALL;
c2ab64d0 JB	133	return -EINVAL;
	134	}
	135
	136	/* whatever mask they set, we just allow one CPU */
	137	cpu_dest = first_cpu(*dest);
	138	*dest = cpumask_of_cpu(cpu_dest);
	139
	140	return 0;
	141	}
	142
	143	static void cpu_set_affinity_irq(unsigned int irq, cpumask_t dest)
	144	{
	145	if (cpu_check_affinity(irq, &dest))
	146	return;
	147
a53da52f	148	irq_desc[irq].affinity = dest;
c2ab64d0 JB	149	}
	150	#endif
	151
1da177e4 LT	152	static struct hw_interrupt_type cpu_interrupt_type = {
	153	.typename = "CPU",
	154	.startup = cpu_startup_irq,
	155	.shutdown = cpu_disable_irq,
	156	.enable = cpu_enable_irq,
	157	.disable = cpu_disable_irq,
7085689e JB	158	.ack = cpu_ack_irq,
7085689e JB	159	.end = cpu_end_irq,
c2ab64d0 JB	160	#ifdef CONFIG_SMP
	161	.set_affinity = cpu_set_affinity_irq,
	162	#endif
c0ad90a3 IM	163	/* XXX: Needs to be written. We managed without it so far, but
	164	* we really ought to write it.
	165	*/
	166	.retrigger = NULL,
1da177e4 LT	167	};
	168
	169	int show_interrupts(struct seq_file p, void v)
	170	{
	171	int i = (loff_t ) v, j;
	172	unsigned long flags;
	173
	174	if (i == 0) {
	175	seq_puts(p, " ");
	176	for_each_online_cpu(j)
	177	seq_printf(p, " CPU%d", j);
	178
	179	#ifdef PARISC_IRQ_CR16_COUNTS
	180	seq_printf(p, " [min/avg/max] (CPU cycle counts)");
	181	#endif
	182	seq_putc(p, '\n');
	183	}
	184
	185	if (i < NR_IRQS) {
	186	struct irqaction *action;
	187
	188	spin_lock_irqsave(&irq_desc[i].lock, flags);
	189	action = irq_desc[i].action;
	190	if (!action)
	191	goto skip;
	192	seq_printf(p, "%3d: ", i);
	193	#ifdef CONFIG_SMP
	194	for_each_online_cpu(j)
	195	seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
	196	#else
	197	seq_printf(p, "%10u ", kstat_irqs(i));
	198	#endif
	199
d1bef4ed	200	seq_printf(p, " %14s", irq_desc[i].chip->typename);
1da177e4 LT	201	#ifndef PARISC_IRQ_CR16_COUNTS
	202	seq_printf(p, " %s", action->name);
	203
	204	while ((action = action->next))
	205	seq_printf(p, ", %s", action->name);
	206	#else
	207	for ( ;action; action = action->next) {
	208	unsigned int k, avg, min, max;
	209
	210	min = max = action->cr16_hist[0];
	211
	212	for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) {
	213	int hist = action->cr16_hist[k];
	214
	215	if (hist) {
	216	avg += hist;
	217	} else
	218	break;
	219
	220	if (hist > max) max = hist;
	221	if (hist < min) min = hist;
	222	}
	223
	224	avg /= k;
	225	seq_printf(p, " %s[%d/%d/%d]", action->name,
	226	min,avg,max);
	227	}
	228	#endif
	229
	230	seq_putc(p, '\n');
	231	skip:
	232	spin_unlock_irqrestore(&irq_desc[i].lock, flags);
	233	}
	234
	235	return 0;
	236	}
	237
	238
	239
	240	/*
	241	** The following form a "set": Virtual IRQ, Transaction Address, Trans Data.
	242	** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit.
	243	**
	244	** To use txn_XXX() interfaces, get a Virtual IRQ first.
	245	** Then use that to get the Transaction address and data.
	246	*/
	247
5cfe87d3	248	int cpu_claim_irq(unsigned int irq, struct irq_chip type, void data)
1da177e4 LT	249	{
	250	if (irq_desc[irq].action)
	251	return -EBUSY;
d1bef4ed	252	if (irq_desc[irq].chip != &cpu_interrupt_type)
1da177e4 LT	253	return -EBUSY;
	254
	255	if (type) {
d1bef4ed IM	256	irq_desc[irq].chip = type;
d1bef4ed IM	257	irq_desc[irq].chip_data = data;
1da177e4 LT	258	cpu_interrupt_type.enable(irq);
	259	}
	260	return 0;
	261	}
	262
	263	int txn_claim_irq(int irq)
	264	{
	265	return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
	266	}
	267
	268	/*
	269	* The bits_wide parameter accommodates the limitations of the HW/SW which
	270	* use these bits:
	271	* Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register)
	272	* V-class (EPIC): 6 bits
	273	* N/L/A-class (iosapic): 8 bits
	274	* PCI 2.2 MSI: 16 bits
	275	* Some PCI devices: 32 bits (Symbios SCSI/ATM/HyperFabric)
	276	*
	277	* On the service provider side:
	278	* o PA 1.1 (and PA2.0 narrow mode) 5-bits (width of EIR register)
	279	* o PA 2.0 wide mode 6-bits (per processor)
	280	* o IA64 8-bits (0-256 total)
	281	*
	282	* So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported
	283	* by the processor...and the N/L-class I/O subsystem supports more bits than
	284	* PA2.0 has. The first case is the problem.
	285	*/
	286	int txn_alloc_irq(unsigned int bits_wide)
	287	{
	288	int irq;
	289
	290	/* never return irq 0 cause that's the interval timer */
	291	for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) {
	292	if (cpu_claim_irq(irq, NULL, NULL) < 0)
	293	continue;
	294	if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide))
	295	continue;
	296	return irq;
	297	}
	298
	299	/* unlikely, but be prepared */
	300	return -1;
	301	}
	302
03afe22f	303
c2ab64d0 JB	304	unsigned long txn_affinity_addr(unsigned int irq, int cpu)
c2ab64d0 JB	305	{
03afe22f	306	#ifdef CONFIG_SMP
a53da52f	307	irq_desc[irq].affinity = cpumask_of_cpu(cpu);
03afe22f	308	#endif
c2ab64d0 JB	309
	310	return cpu_data[cpu].txn_addr;
	311	}
	312
03afe22f	313
1da177e4 LT	314	unsigned long txn_alloc_addr(unsigned int virt_irq)
	315	{
	316	static int next_cpu = -1;
	317
	318	next_cpu++; /* assign to "next" CPU we want this bugger on */
	319
	320	/* validate entry */
	321	while ((next_cpu < NR_CPUS) && (!cpu_data[next_cpu].txn_addr \|\|
	322	!cpu_online(next_cpu)))
	323	next_cpu++;
	324
	325	if (next_cpu >= NR_CPUS)
	326	next_cpu = 0; /* nothing else, assign monarch */
	327
c2ab64d0	328	return txn_affinity_addr(virt_irq, next_cpu);
1da177e4 LT	329	}
	330
	331
	332	unsigned int txn_alloc_data(unsigned int virt_irq)
	333	{
	334	return virt_irq - CPU_IRQ_BASE;
	335	}
	336
7085689e JB	337	static inline int eirr_to_irq(unsigned long eirr)
7085689e JB	338	{
0c2de3c6	339	int bit = fls_long(eirr);
7085689e JB	340	return (BITS_PER_LONG - bit) + TIMER_IRQ;
	341	}
	342
1da177e4 LT	343	/* ONLY called from entry.S:intr_extint() */
	344	void do_cpu_irq_mask(struct pt_regs *regs)
	345	{
e11e30a0	346	struct pt_regs *old_regs;
1da177e4	347	unsigned long eirr_val;
7085689e	348	int irq, cpu = smp_processor_id();
03afe22f	349	#ifdef CONFIG_SMP
7085689e	350	cpumask_t dest;
03afe22f	351	#endif
1da177e4	352
e11e30a0	353	old_regs = set_irq_regs(regs);
7085689e JB	354	local_irq_disable();
7085689e JB	355	irq_enter();
1da177e4	356
7085689e JB	357	eirr_val = mfctl(23) & cpu_eiem & global_ack_eiem &
	358	per_cpu(local_ack_eiem, cpu);
	359	if (!eirr_val)
	360	goto set_out;
	361	irq = eirr_to_irq(eirr_val);
c2ab64d0	362
7085689e JB	363	#ifdef CONFIG_SMP
	364	dest = irq_desc[irq].affinity;
	365	if (CHECK_IRQ_PER_CPU(irq_desc[irq].status) &&
	366	!cpu_isset(smp_processor_id(), dest)) {
	367	int cpu = first_cpu(dest);
	368
	369	printk(KERN_DEBUG "redirecting irq %d from CPU %d to %d\n",
	370	irq, smp_processor_id(), cpu);
	371	gsc_writel(irq + CPU_IRQ_BASE,
	372	cpu_data[cpu].hpa);
	373	goto set_out;
1da177e4	374	}
7085689e	375	#endif
be577a52	376	__do_IRQ(irq);
3f902886	377
7085689e	378	out:
1da177e4	379	irq_exit();
e11e30a0	380	set_irq_regs(old_regs);
7085689e	381	return;
1da177e4	382
7085689e JB	383	set_out:
	384	set_eiem(cpu_eiem & global_ack_eiem & per_cpu(local_ack_eiem, cpu));
	385	goto out;
	386	}
1da177e4 LT	387
	388	static struct irqaction timer_action = {
	389	.handler = timer_interrupt,
	390	.name = "timer",
57501c70	391	.flags = IRQF_DISABLED \| IRQF_TIMER \| IRQF_PERCPU \| IRQF_IRQPOLL,
1da177e4 LT	392	};
	393
	394	#ifdef CONFIG_SMP
	395	static struct irqaction ipi_action = {
	396	.handler = ipi_interrupt,
	397	.name = "IPI",
7085689e	398	.flags = IRQF_DISABLED \| IRQF_PERCPU,
1da177e4 LT	399	};
	400	#endif
	401
	402	static void claim_cpu_irqs(void)
	403	{
	404	int i;
	405	for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
d1bef4ed	406	irq_desc[i].chip = &cpu_interrupt_type;
1da177e4 LT	407	}
	408
	409	irq_desc[TIMER_IRQ].action = &timer_action;
	410	irq_desc[TIMER_IRQ].status \|= IRQ_PER_CPU;
	411	#ifdef CONFIG_SMP
	412	irq_desc[IPI_IRQ].action = &ipi_action;
	413	irq_desc[IPI_IRQ].status = IRQ_PER_CPU;
	414	#endif
	415	}
	416
	417	void __init init_IRQ(void)
	418	{
	419	local_irq_disable(); /* PARANOID - should already be disabled */
	420	mtctl(~0UL, 23); /* EIRR : clear all pending external intr */
	421	claim_cpu_irqs();
	422	#ifdef CONFIG_SMP
	423	if (!cpu_eiem)
	424	cpu_eiem = EIEM_MASK(IPI_IRQ) \| EIEM_MASK(TIMER_IRQ);
	425	#else
	426	cpu_eiem = EIEM_MASK(TIMER_IRQ);
	427	#endif
	428	set_eiem(cpu_eiem); /* EIEM : enable all external intr */
	429
	430	}
	431
1da177e4 LT	432	void ack_bad_irq(unsigned int irq)
	433	{
	434	printk("unexpected IRQ %d\n", irq);
	435	}