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

/*
 *  arch/ppc/kernel/irq.c
 *
 *  Derived from arch/i386/kernel/irq.c
 *    Copyright (C) 1992 Linus Torvalds
 *  Adapted from arch/i386 by Gary Thomas
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
 *    Copyright (C) 1996-2001 Cort Dougan
 *  Adapted for Power Macintosh by Paul Mackerras
 *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
 *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
 *
 * 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.
 *
 * This file contains the code used by various IRQ handling routines:
 * asking for different IRQ's should be done through these routines
 * instead of just grabbing them. Thus setups with different IRQ numbers
 * shouldn't result in any weird surprises, and installing new handlers
 * should be easier.
 *
 * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
 * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
 * mask register (of which only 16 are defined), hence the weird shifting
 * and complement of the cached_irq_mask.  I want to be able to stuff
 * this right into the SIU SMASK register.
 * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
 * to reduce code space and undefined function references.
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/threads.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/config.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/proc_fs.h>
#include <linux/random.h>
#include <linux/seq_file.h>
#include <linux/cpumask.h>
#include <linux/profile.h>
#include <linux/bitops.h>
#ifdef CONFIG_PPC64
#include <linux/kallsyms.h>
#endif

#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/cache.h>
#include <asm/prom.h>
#include <asm/ptrace.h>
#include <asm/machdep.h>
#ifdef CONFIG_PPC64
#include <asm/iseries/it_lp_queue.h>
#include <asm/paca.h>
#endif

int __irq_offset_value;
#ifdef CONFIG_PPC32
EXPORT_SYMBOL(__irq_offset_value);
#endif

static int ppc_spurious_interrupts;

#ifdef CONFIG_PPC32
#define NR_MASK_WORDS	((NR_IRQS + 31) / 32)

unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
atomic_t ppc_n_lost_interrupts;

#ifdef CONFIG_TAU_INT
extern int tau_initialized;
extern int tau_interrupts(int);
#endif

#if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
extern atomic_t ipi_recv;
extern atomic_t ipi_sent;
#endif
#endif /* CONFIG_PPC32 */

#ifdef CONFIG_PPC64
EXPORT_SYMBOL(irq_desc);

int distribute_irqs = 1;
u64 ppc64_interrupt_controller;
#endif /* CONFIG_PPC64 */

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

	if (i == 0) {
		seq_puts(p, "           ");
		for_each_online_cpu(j)
			seq_printf(p, "CPU%d       ", j);
		seq_putc(p, '\n');
	}

	if (i < NR_IRQS) {
		desc = get_irq_desc(i);
		spin_lock_irqsave(&desc->lock, flags);
		action = desc->action;
		if (!action || !action->handler)
			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 /* CONFIG_SMP */
		if (desc->handler)
			seq_printf(p, " %s ", desc->handler->typename);
		else
			seq_puts(p, "  None      ");
		seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
		seq_printf(p, "    %s", action->name);
		for (action = action->next; action; action = action->next)
			seq_printf(p, ", %s", action->name);
		seq_putc(p, '\n');
skip:
		spin_unlock_irqrestore(&desc->lock, flags);
	} else if (i == NR_IRQS) {
#ifdef CONFIG_PPC32
#ifdef CONFIG_TAU_INT
		if (tau_initialized){
			seq_puts(p, "TAU: ");
			for (j = 0; j < NR_CPUS; j++)
				if (cpu_online(j))
					seq_printf(p, "%10u ", tau_interrupts(j));
			seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
		}
#endif
#if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
		/* should this be per processor send/receive? */
		seq_printf(p, "IPI (recv/sent): %10u/%u\n",
				atomic_read(&ipi_recv), atomic_read(&ipi_sent));
#endif
#endif /* CONFIG_PPC32 */
		seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
	}
	return 0;
}

#ifdef CONFIG_HOTPLUG_CPU
void fixup_irqs(cpumask_t map)
{
	unsigned int irq;
	static int warned;

	for_each_irq(irq) {
		cpumask_t mask;

		if (irq_desc[irq].status & IRQ_PER_CPU)
			continue;

		cpus_and(mask, irq_affinity[irq], map);
		if (any_online_cpu(mask) == NR_CPUS) {
			printk("Breaking affinity for irq %i\n", irq);
			mask = map;
		}
		if (irq_desc[irq].handler->set_affinity)
			irq_desc[irq].handler->set_affinity(irq, mask);
		else if (irq_desc[irq].action && !(warned++))
			printk("Cannot set affinity for irq %i\n", irq);
	}

	local_irq_enable();
	mdelay(1);
	local_irq_disable();
}
#endif

void do_IRQ(struct pt_regs *regs)
{
	int irq;
#ifdef CONFIG_IRQSTACKS
	struct thread_info *curtp, *irqtp;
#endif

        irq_enter();

#ifdef CONFIG_DEBUG_STACKOVERFLOW
	/* Debugging check for stack overflow: is there less than 2KB free? */
	{
		long sp;

		sp = __get_SP() & (THREAD_SIZE-1);

		if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
			printk("do_IRQ: stack overflow: %ld\n",
				sp - sizeof(struct thread_info));
			dump_stack();
		}
	}
#endif

	/*
	 * Every platform is required to implement ppc_md.get_irq.
	 * This function will either return an irq number or -1 to
	 * indicate there are no more pending.
	 * The value -2 is for buggy hardware and means that this IRQ
	 * has already been handled. -- Tom
	 */
	irq = ppc_md.get_irq(regs);

	if (irq >= 0) {
#ifdef CONFIG_IRQSTACKS
		/* Switch to the irq stack to handle this */
		curtp = current_thread_info();
		irqtp = hardirq_ctx[smp_processor_id()];
		if (curtp != irqtp) {
			irqtp->task = curtp->task;
			irqtp->flags = 0;
			call___do_IRQ(irq, regs, irqtp);
			irqtp->task = NULL;
			if (irqtp->flags)
				set_bits(irqtp->flags, &curtp->flags);
		} else
#endif
			__do_IRQ(irq, regs);
	} else if (irq != -2)
		/* That's not SMP safe ... but who cares ? */
		ppc_spurious_interrupts++;

        irq_exit();

#ifdef CONFIG_PPC_ISERIES
	{
		struct paca_struct *lpaca = get_paca();

		if (lpaca->lppaca.int_dword.fields.decr_int) {
			lpaca->lppaca.int_dword.fields.decr_int = 0;
			/* Signal a fake decrementer interrupt */
			timer_interrupt(regs);
		}
	}
#endif
}

void __init init_IRQ(void)
{
#ifdef CONFIG_PPC64
	static int once = 0;

	if (once)
		return;

	once++;

#endif
	ppc_md.init_IRQ();
#ifdef CONFIG_PPC64
	irq_ctx_init();
#endif
}

#ifdef CONFIG_PPC64
/*
 * Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
 */

#define UNDEFINED_IRQ 0xffffffff
unsigned int virt_irq_to_real_map[NR_IRQS];

/*
 * Don't use virtual irqs 0, 1, 2 for devices.
 * The pcnet32 driver considers interrupt numbers < 2 to be invalid,
 * and 2 is the XICS IPI interrupt.
 * We limit virtual irqs to 17 less than NR_IRQS so that when we
 * offset them by 16 (to reserve the first 16 for ISA interrupts)
 * we don't end up with an interrupt number >= NR_IRQS.
 */
#define MIN_VIRT_IRQ	3
#define MAX_VIRT_IRQ	(NR_IRQS - NUM_ISA_INTERRUPTS - 1)
#define NR_VIRT_IRQS	(MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)

void
virt_irq_init(void)
{
	int i;
	for (i = 0; i < NR_IRQS; i++)
		virt_irq_to_real_map[i] = UNDEFINED_IRQ;
}

/* Create a mapping for a real_irq if it doesn't already exist.
 * Return the virtual irq as a convenience.
 */
int virt_irq_create_mapping(unsigned int real_irq)
{
	unsigned int virq, first_virq;
	static int warned;

	if (ppc64_interrupt_controller == IC_OPEN_PIC)
		return real_irq;	/* no mapping for openpic (for now) */

	if (ppc64_interrupt_controller == IC_CELL_PIC)
		return real_irq;	/* no mapping for iic either */

	/* don't map interrupts < MIN_VIRT_IRQ */
	if (real_irq < MIN_VIRT_IRQ) {
		virt_irq_to_real_map[real_irq] = real_irq;
		return real_irq;
	}

	/* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
	virq = real_irq;
	if (virq > MAX_VIRT_IRQ)
		virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;

	/* search for this number or a free slot */
	first_virq = virq;
	while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
		if (virt_irq_to_real_map[virq] == real_irq)
			return virq;
		if (++virq > MAX_VIRT_IRQ)
			virq = MIN_VIRT_IRQ;
		if (virq == first_virq)
			goto nospace;	/* oops, no free slots */
	}

	virt_irq_to_real_map[virq] = real_irq;
	return virq;

 nospace:
	if (!warned) {
		printk(KERN_CRIT "Interrupt table is full\n");
		printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
		       "in your kernel sources and rebuild.\n", NR_IRQS);
		warned = 1;
	}
	return NO_IRQ;
}

/*
 * In most cases will get a hit on the very first slot checked in the
 * virt_irq_to_real_map.  Only when there are a large number of
 * IRQs will this be expensive.
 */
unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
{
	unsigned int virq;
	unsigned int first_virq;

	virq = real_irq;

	if (virq > MAX_VIRT_IRQ)
		virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;

	first_virq = virq;

	do {
		if (virt_irq_to_real_map[virq] == real_irq)
			return virq;

		virq++;

		if (virq >= MAX_VIRT_IRQ)
			virq = 0;

	} while (first_virq != virq);

	return NO_IRQ;

}

#ifdef CONFIG_IRQSTACKS
struct thread_info *softirq_ctx[NR_CPUS];
struct thread_info *hardirq_ctx[NR_CPUS];

void irq_ctx_init(void)
{
	struct thread_info *tp;
	int i;

	for_each_cpu(i) {
		memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
		tp = softirq_ctx[i];
		tp->cpu = i;
		tp->preempt_count = SOFTIRQ_OFFSET;

		memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
		tp = hardirq_ctx[i];
		tp->cpu = i;
		tp->preempt_count = HARDIRQ_OFFSET;
	}
}

void do_softirq(void)
{
	unsigned long flags;
	struct thread_info *curtp, *irqtp;

	if (in_interrupt())
		return;

	local_irq_save(flags);

	if (local_softirq_pending()) {
		curtp = current_thread_info();
		irqtp = softirq_ctx[smp_processor_id()];
		irqtp->task = curtp->task;
		call_do_softirq(irqtp);
		irqtp->task = NULL;
	}

	local_irq_restore(flags);
}
EXPORT_SYMBOL(do_softirq);

#endif /* CONFIG_IRQSTACKS */

static int __init setup_noirqdistrib(char *str)
{
	distribute_irqs = 0;
	return 1;
}

__setup("noirqdistrib", setup_noirqdistrib);
#endif /* CONFIG_PPC64 */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* arch/ppc/kernel/irq.c
	3	*
	4	* Derived from arch/i386/kernel/irq.c
	5	* Copyright (C) 1992 Linus Torvalds
	6	* Adapted from arch/i386 by Gary Thomas
	7	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
756e7104 SR	8	* Updated and modified by Cort Dougan <cort@fsmlabs.com>
756e7104 SR	9	* Copyright (C) 1996-2001 Cort Dougan
1da177e4 LT	10	* Adapted for Power Macintosh by Paul Mackerras
	11	* Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
	12	* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
756e7104	13	*
1da177e4 LT	14	* This program is free software; you can redistribute it and/or
	15	* modify it under the terms of the GNU General Public License
	16	* as published by the Free Software Foundation; either version
	17	* 2 of the License, or (at your option) any later version.
	18	*
	19	* This file contains the code used by various IRQ handling routines:
	20	* asking for different IRQ's should be done through these routines
	21	* instead of just grabbing them. Thus setups with different IRQ numbers
	22	* shouldn't result in any weird surprises, and installing new handlers
	23	* should be easier.
756e7104 SR	24	*
	25	* The MPC8xx has an interrupt mask in the SIU. If a bit is set, the
	26	* interrupt is _enabled_. As expected, IRQ0 is bit 0 in the 32-bit
	27	* mask register (of which only 16 are defined), hence the weird shifting
	28	* and complement of the cached_irq_mask. I want to be able to stuff
	29	* this right into the SIU SMASK register.
	30	* Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
	31	* to reduce code space and undefined function references.
1da177e4 LT	32	*/
	33
	34	#include <linux/errno.h>
	35	#include <linux/module.h>
	36	#include <linux/threads.h>
	37	#include <linux/kernel_stat.h>
	38	#include <linux/signal.h>
	39	#include <linux/sched.h>
756e7104	40	#include <linux/ptrace.h>
1da177e4 LT	41	#include <linux/ioport.h>
	42	#include <linux/interrupt.h>
	43	#include <linux/timex.h>
	44	#include <linux/config.h>
	45	#include <linux/init.h>
	46	#include <linux/slab.h>
	47	#include <linux/pci.h>
	48	#include <linux/delay.h>
	49	#include <linux/irq.h>
	50	#include <linux/proc_fs.h>
	51	#include <linux/random.h>
756e7104 SR	52	#include <linux/seq_file.h>
756e7104 SR	53	#include <linux/cpumask.h>
1da177e4 LT	54	#include <linux/profile.h>
1da177e4 LT	55	#include <linux/bitops.h>
756e7104 SR	56	#ifdef CONFIG_PPC64
	57	#include <linux/kallsyms.h>
	58	#endif
1da177e4 LT	59
	60	#include <asm/uaccess.h>
	61	#include <asm/system.h>
	62	#include <asm/io.h>
	63	#include <asm/pgtable.h>
	64	#include <asm/irq.h>
	65	#include <asm/cache.h>
	66	#include <asm/prom.h>
	67	#include <asm/ptrace.h>
1da177e4	68	#include <asm/machdep.h>
756e7104 SR	69	#ifdef CONFIG_PPC64
756e7104 SR	70	#include <asm/iseries/it_lp_queue.h>
1da177e4	71	#include <asm/paca.h>
756e7104	72	#endif
1da177e4	73
868accb7 SR	74	int __irq_offset_value;
	75	#ifdef CONFIG_PPC32
	76	EXPORT_SYMBOL(__irq_offset_value);
	77	#endif
	78
756e7104 SR	79	static int ppc_spurious_interrupts;
756e7104 SR	80
756e7104 SR	81	#ifdef CONFIG_PPC32
	82	#define NR_MASK_WORDS ((NR_IRQS + 31) / 32)
	83
	84	unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
	85	atomic_t ppc_n_lost_interrupts;
	86
	87	#ifdef CONFIG_TAU_INT
	88	extern int tau_initialized;
	89	extern int tau_interrupts(int);
	90	#endif
	91
	92	#if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
	93	extern atomic_t ipi_recv;
	94	extern atomic_t ipi_sent;
	95	#endif
	96	#endif /* CONFIG_PPC32 */
	97
	98	#ifdef CONFIG_PPC64
1da177e4 LT	99	EXPORT_SYMBOL(irq_desc);
	100
	101	int distribute_irqs = 1;
1da177e4	102	u64 ppc64_interrupt_controller;
756e7104	103	#endif /* CONFIG_PPC64 */
1da177e4 LT	104
	105	int show_interrupts(struct seq_file p, void v)
	106	{
756e7104 SR	107	int i = (loff_t )v, j;
756e7104 SR	108	struct irqaction *action;
1da177e4 LT	109	irq_desc_t *desc;
	110	unsigned long flags;
	111
	112	if (i == 0) {
756e7104 SR	113	seq_puts(p, " ");
	114	for_each_online_cpu(j)
	115	seq_printf(p, "CPU%d ", j);
1da177e4 LT	116	seq_putc(p, '\n');
	117	}
	118
	119	if (i < NR_IRQS) {
	120	desc = get_irq_desc(i);
	121	spin_lock_irqsave(&desc->lock, flags);
	122	action = desc->action;
	123	if (!action \|\| !action->handler)
	124	goto skip;
	125	seq_printf(p, "%3d: ", i);
	126	#ifdef CONFIG_SMP
756e7104 SR	127	for_each_online_cpu(j)
756e7104 SR	128	seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
1da177e4 LT	129	#else
	130	seq_printf(p, "%10u ", kstat_irqs(i));
	131	#endif /* CONFIG_SMP */
	132	if (desc->handler)
756e7104	133	seq_printf(p, " %s ", desc->handler->typename);
1da177e4	134	else
756e7104	135	seq_puts(p, " None ");
1da177e4	136	seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge ");
756e7104 SR	137	seq_printf(p, " %s", action->name);
756e7104 SR	138	for (action = action->next; action; action = action->next)
1da177e4 LT	139	seq_printf(p, ", %s", action->name);
	140	seq_putc(p, '\n');
	141	skip:
	142	spin_unlock_irqrestore(&desc->lock, flags);
756e7104 SR	143	} else if (i == NR_IRQS) {
	144	#ifdef CONFIG_PPC32
	145	#ifdef CONFIG_TAU_INT
	146	if (tau_initialized){
	147	seq_puts(p, "TAU: ");
	148	for (j = 0; j < NR_CPUS; j++)
	149	if (cpu_online(j))
	150	seq_printf(p, "%10u ", tau_interrupts(j));
	151	seq_puts(p, " PowerPC Thermal Assist (cpu temp)\n");
	152	}
	153	#endif
	154	#if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
	155	/* should this be per processor send/receive? */
	156	seq_printf(p, "IPI (recv/sent): %10u/%u\n",
	157	atomic_read(&ipi_recv), atomic_read(&ipi_sent));
	158	#endif
	159	#endif /* CONFIG_PPC32 */
1da177e4	160	seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
756e7104	161	}
1da177e4 LT	162	return 0;
	163	}
	164
	165	#ifdef CONFIG_HOTPLUG_CPU
	166	void fixup_irqs(cpumask_t map)
	167	{
	168	unsigned int irq;
	169	static int warned;
	170
	171	for_each_irq(irq) {
	172	cpumask_t mask;
	173
	174	if (irq_desc[irq].status & IRQ_PER_CPU)
	175	continue;
	176
	177	cpus_and(mask, irq_affinity[irq], map);
	178	if (any_online_cpu(mask) == NR_CPUS) {
	179	printk("Breaking affinity for irq %i\n", irq);
	180	mask = map;
	181	}
	182	if (irq_desc[irq].handler->set_affinity)
	183	irq_desc[irq].handler->set_affinity(irq, mask);
	184	else if (irq_desc[irq].action && !(warned++))
	185	printk("Cannot set affinity for irq %i\n", irq);
	186	}
	187
	188	local_irq_enable();
	189	mdelay(1);
	190	local_irq_disable();
	191	}
	192	#endif
	193
1da177e4 LT	194	void do_IRQ(struct pt_regs *regs)
	195	{
	196	int irq;
b709c083 SR	197	#ifdef CONFIG_IRQSTACKS
	198	struct thread_info curtp, irqtp;
	199	#endif
1da177e4	200
756e7104	201	irq_enter();
1da177e4 LT	202
	203	#ifdef CONFIG_DEBUG_STACKOVERFLOW
	204	/* Debugging check for stack overflow: is there less than 2KB free? */
	205	{
	206	long sp;
	207
	208	sp = __get_SP() & (THREAD_SIZE-1);
	209
	210	if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
	211	printk("do_IRQ: stack overflow: %ld\n",
	212	sp - sizeof(struct thread_info));
	213	dump_stack();
	214	}
	215	}
	216	#endif
	217
756e7104 SR	218	/*
	219	* Every platform is required to implement ppc_md.get_irq.
	220	* This function will either return an irq number or -1 to
	221	* indicate there are no more pending.
	222	* The value -2 is for buggy hardware and means that this IRQ
	223	* has already been handled. -- Tom
	224	*/
1da177e4 LT	225	irq = ppc_md.get_irq(regs);
1da177e4 LT	226
b709c083 SR	227	if (irq >= 0) {
	228	#ifdef CONFIG_IRQSTACKS
	229	/* Switch to the irq stack to handle this */
	230	curtp = current_thread_info();
	231	irqtp = hardirq_ctx[smp_processor_id()];
	232	if (curtp != irqtp) {
	233	irqtp->task = curtp->task;
	234	irqtp->flags = 0;
d4be4f37	235	call___do_IRQ(irq, regs, irqtp);
b709c083 SR	236	irqtp->task = NULL;
	237	if (irqtp->flags)
	238	set_bits(irqtp->flags, &curtp->flags);
	239	} else
	240	#endif
d4be4f37	241	__do_IRQ(irq, regs);
e199500c SR	242	} else if (irq != -2)
	243	/* That's not SMP safe ... but who cares ? */
	244	ppc_spurious_interrupts++;
	245
756e7104	246	irq_exit();
756e7104	247
e199500c SR	248	#ifdef CONFIG_PPC_ISERIES
	249	{
	250	struct paca_struct *lpaca = get_paca();
	251
	252	if (lpaca->lppaca.int_dword.fields.decr_int) {
	253	lpaca->lppaca.int_dword.fields.decr_int = 0;
	254	/* Signal a fake decrementer interrupt */
	255	timer_interrupt(regs);
	256	}
	257	}
	258	#endif
	259	}
1da177e4 LT	260
	261	void __init init_IRQ(void)
	262	{
756e7104	263	#ifdef CONFIG_PPC64
1da177e4 LT	264	static int once = 0;
	265
	266	if (once)
	267	return;
	268
	269	once++;
	270
756e7104	271	#endif
1da177e4	272	ppc_md.init_IRQ();
756e7104	273	#ifdef CONFIG_PPC64
1da177e4	274	irq_ctx_init();
756e7104	275	#endif
1da177e4 LT	276	}
1da177e4 LT	277
756e7104	278	#ifdef CONFIG_PPC64
1da177e4 LT	279	/*
	280	* Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
	281	*/
	282
	283	#define UNDEFINED_IRQ 0xffffffff
	284	unsigned int virt_irq_to_real_map[NR_IRQS];
	285
	286	/*
	287	* Don't use virtual irqs 0, 1, 2 for devices.
	288	* The pcnet32 driver considers interrupt numbers < 2 to be invalid,
	289	* and 2 is the XICS IPI interrupt.
	290	* We limit virtual irqs to 17 less than NR_IRQS so that when we
	291	* offset them by 16 (to reserve the first 16 for ISA interrupts)
	292	* we don't end up with an interrupt number >= NR_IRQS.
	293	*/
	294	#define MIN_VIRT_IRQ 3
	295	#define MAX_VIRT_IRQ (NR_IRQS - NUM_ISA_INTERRUPTS - 1)
	296	#define NR_VIRT_IRQS (MAX_VIRT_IRQ - MIN_VIRT_IRQ + 1)
	297
	298	void
	299	virt_irq_init(void)
	300	{
	301	int i;
	302	for (i = 0; i < NR_IRQS; i++)
	303	virt_irq_to_real_map[i] = UNDEFINED_IRQ;
	304	}
	305
	306	/* Create a mapping for a real_irq if it doesn't already exist.
	307	* Return the virtual irq as a convenience.
	308	*/
	309	int virt_irq_create_mapping(unsigned int real_irq)
	310	{
	311	unsigned int virq, first_virq;
	312	static int warned;
	313
	314	if (ppc64_interrupt_controller == IC_OPEN_PIC)
	315	return real_irq; /* no mapping for openpic (for now) */
	316
f3f66f59	317	if (ppc64_interrupt_controller == IC_CELL_PIC)
fef1c772 AB	318	return real_irq; /* no mapping for iic either */
fef1c772 AB	319
1da177e4 LT	320	/* don't map interrupts < MIN_VIRT_IRQ */
	321	if (real_irq < MIN_VIRT_IRQ) {
	322	virt_irq_to_real_map[real_irq] = real_irq;
	323	return real_irq;
	324	}
	325
	326	/* map to a number between MIN_VIRT_IRQ and MAX_VIRT_IRQ */
	327	virq = real_irq;
	328	if (virq > MAX_VIRT_IRQ)
	329	virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
	330
	331	/* search for this number or a free slot */
	332	first_virq = virq;
	333	while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
	334	if (virt_irq_to_real_map[virq] == real_irq)
	335	return virq;
	336	if (++virq > MAX_VIRT_IRQ)
	337	virq = MIN_VIRT_IRQ;
	338	if (virq == first_virq)
	339	goto nospace; /* oops, no free slots */
	340	}
	341
	342	virt_irq_to_real_map[virq] = real_irq;
	343	return virq;
	344
	345	nospace:
	346	if (!warned) {
	347	printk(KERN_CRIT "Interrupt table is full\n");
	348	printk(KERN_CRIT "Increase NR_IRQS (currently %d) "
	349	"in your kernel sources and rebuild.\n", NR_IRQS);
	350	warned = 1;
	351	}
	352	return NO_IRQ;
	353	}
	354
	355	/*
	356	* In most cases will get a hit on the very first slot checked in the
	357	* virt_irq_to_real_map. Only when there are a large number of
	358	* IRQs will this be expensive.
	359	*/
	360	unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
	361	{
	362	unsigned int virq;
	363	unsigned int first_virq;
	364
	365	virq = real_irq;
	366
	367	if (virq > MAX_VIRT_IRQ)
	368	virq = (virq % NR_VIRT_IRQS) + MIN_VIRT_IRQ;
	369
	370	first_virq = virq;
	371
	372	do {
	373	if (virt_irq_to_real_map[virq] == real_irq)
	374	return virq;
	375
	376	virq++;
	377
	378	if (virq >= MAX_VIRT_IRQ)
	379	virq = 0;
	380
	381	} while (first_virq != virq);
	382
	383	return NO_IRQ;
384
385	}
386
1da177e4 LT	387	#ifdef CONFIG_IRQSTACKS
	388	struct thread_info *softirq_ctx[NR_CPUS];
	389	struct thread_info *hardirq_ctx[NR_CPUS];
	390
	391	void irq_ctx_init(void)
	392	{
	393	struct thread_info *tp;
	394	int i;
	395
	396	for_each_cpu(i) {
	397	memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
	398	tp = softirq_ctx[i];
	399	tp->cpu = i;
	400	tp->preempt_count = SOFTIRQ_OFFSET;
	401
	402	memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
	403	tp = hardirq_ctx[i];
	404	tp->cpu = i;
	405	tp->preempt_count = HARDIRQ_OFFSET;
	406	}
	407	}
	408
	409	void do_softirq(void)
	410	{
	411	unsigned long flags;
	412	struct thread_info curtp, irqtp;
	413
	414	if (in_interrupt())
	415	return;
	416
	417	local_irq_save(flags);
	418
	419	if (local_softirq_pending()) {
	420	curtp = current_thread_info();
	421	irqtp = softirq_ctx[smp_processor_id()];
	422	irqtp->task = curtp->task;
	423	call_do_softirq(irqtp);
	424	irqtp->task = NULL;
	425	}
	426
	427	local_irq_restore(flags);
	428	}
	429	EXPORT_SYMBOL(do_softirq);
	430
	431	#endif /* CONFIG_IRQSTACKS */
	432
	433	static int __init setup_noirqdistrib(char *str)
	434	{
	435	distribute_irqs = 0;
	436	return 1;
	437	}
	438
	439	__setup("noirqdistrib", setup_noirqdistrib);
756e7104	440	#endif /* CONFIG_PPC64 */