[deliverable/linux.git] / kernel / irq / irqdesc.c

/*
 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
 *
 * This file contains the interrupt descriptor management code
 *
 * Detailed information is available in Documentation/DocBook/genericirq
 *
 */
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/radix-tree.h>
#include <linux/bitmap.h>

#include "internals.h"

/*
 * lockdep: we want to handle all irq_desc locks as a single lock-class:
 */
static struct lock_class_key irq_desc_lock_class;

#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
static void __init init_irq_default_affinity(void)
{
	alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
	cpumask_setall(irq_default_affinity);
}
#else
static void __init init_irq_default_affinity(void)
{
}
#endif

#ifdef CONFIG_SMP
static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
{
	if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
		return -ENOMEM;

#ifdef CONFIG_GENERIC_PENDING_IRQ
	if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
		free_cpumask_var(desc->irq_data.affinity);
		return -ENOMEM;
	}
#endif
	return 0;
}

static void desc_smp_init(struct irq_desc *desc, int node)
{
	desc->irq_data.node = node;
	cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
#ifdef CONFIG_GENERIC_PENDING_IRQ
	cpumask_clear(desc->pending_mask);
#endif
}

static inline int desc_node(struct irq_desc *desc)
{
	return desc->irq_data.node;
}

#else
static inline int
alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
static inline void desc_smp_init(struct irq_desc *desc, int node) { }
static inline int desc_node(struct irq_desc *desc) { return 0; }
#endif

static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node)
{
	int cpu;

	desc->irq_data.irq = irq;
	desc->irq_data.chip = &no_irq_chip;
	desc->irq_data.chip_data = NULL;
	desc->irq_data.handler_data = NULL;
	desc->irq_data.msi_desc = NULL;
	desc->status = IRQ_DEFAULT_INIT_FLAGS;
	desc->handle_irq = handle_bad_irq;
	desc->depth = 1;
	desc->irq_count = 0;
	desc->irqs_unhandled = 0;
	desc->name = NULL;
	for_each_possible_cpu(cpu)
		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
	desc_smp_init(desc, node);
}

int nr_irqs = NR_IRQS;
EXPORT_SYMBOL_GPL(nr_irqs);

static DEFINE_MUTEX(sparse_irq_lock);
static DECLARE_BITMAP(allocated_irqs, NR_IRQS);

#ifdef CONFIG_SPARSE_IRQ

static RADIX_TREE(irq_desc_tree, GFP_KERNEL);

static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
{
	radix_tree_insert(&irq_desc_tree, irq, desc);
}

struct irq_desc *irq_to_desc(unsigned int irq)
{
	return radix_tree_lookup(&irq_desc_tree, irq);
}

static void delete_irq_desc(unsigned int irq)
{
	radix_tree_delete(&irq_desc_tree, irq);
}

#ifdef CONFIG_SMP
static void free_masks(struct irq_desc *desc)
{
#ifdef CONFIG_GENERIC_PENDING_IRQ
	free_cpumask_var(desc->pending_mask);
#endif
	free_cpumask_var(desc->irq_data.affinity);
}
#else
static inline void free_masks(struct irq_desc *desc) { }
#endif

static struct irq_desc *alloc_desc(int irq, int node)
{
	struct irq_desc *desc;
	gfp_t gfp = GFP_KERNEL;

	desc = kzalloc_node(sizeof(*desc), gfp, node);
	if (!desc)
		return NULL;
	/* allocate based on nr_cpu_ids */
	desc->kstat_irqs = alloc_percpu(unsigned int);
	if (!desc->kstat_irqs)
		goto err_desc;

	if (alloc_masks(desc, gfp, node))
		goto err_kstat;

	raw_spin_lock_init(&desc->lock);
	lockdep_set_class(&desc->lock, &irq_desc_lock_class);

	desc_set_defaults(irq, desc, node);

	return desc;

err_kstat:
	free_percpu(desc->kstat_irqs);
err_desc:
	kfree(desc);
	return NULL;
}

static void free_desc(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);

	unregister_irq_proc(irq, desc);

	mutex_lock(&sparse_irq_lock);
	delete_irq_desc(irq);
	mutex_unlock(&sparse_irq_lock);

	free_masks(desc);
	free_percpu(desc->kstat_irqs);
	kfree(desc);
}

static int alloc_descs(unsigned int start, unsigned int cnt, int node)
{
	struct irq_desc *desc;
	int i;

	for (i = 0; i < cnt; i++) {
		desc = alloc_desc(start + i, node);
		if (!desc)
			goto err;
		mutex_lock(&sparse_irq_lock);
		irq_insert_desc(start + i, desc);
		mutex_unlock(&sparse_irq_lock);
	}
	return start;

err:
	for (i--; i >= 0; i--)
		free_desc(start + i);

	mutex_lock(&sparse_irq_lock);
	bitmap_clear(allocated_irqs, start, cnt);
	mutex_unlock(&sparse_irq_lock);
	return -ENOMEM;
}

struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
{
	int res = irq_alloc_descs(irq, irq, 1, node);

	if (res == -EEXIST || res == irq)
		return irq_to_desc(irq);
	return NULL;
}

int __init early_irq_init(void)
{
	int i, initcnt, node = first_online_node;
	struct irq_desc *desc;

	init_irq_default_affinity();

	/* Let arch update nr_irqs and return the nr of preallocated irqs */
	initcnt = arch_probe_nr_irqs();
	printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);

	for (i = 0; i < initcnt; i++) {
		desc = alloc_desc(i, node);
		set_bit(i, allocated_irqs);
		irq_insert_desc(i, desc);
	}
	return arch_early_irq_init();
}

#else /* !CONFIG_SPARSE_IRQ */

struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
	[0 ... NR_IRQS-1] = {
		.status		= IRQ_DEFAULT_INIT_FLAGS,
		.handle_irq	= handle_bad_irq,
		.depth		= 1,
		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
	}
};

int __init early_irq_init(void)
{
	int count, i, node = first_online_node;
	struct irq_desc *desc;

	init_irq_default_affinity();

	printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);

	desc = irq_desc;
	count = ARRAY_SIZE(irq_desc);

	for (i = 0; i < count; i++) {
		desc[i].irq_data.irq = i;
		desc[i].irq_data.chip = &no_irq_chip;
		/* TODO : do this allocation on-demand ... */
		desc[i].kstat_irqs = alloc_percpu(unsigned int);
		alloc_masks(desc + i, GFP_KERNEL, node);
		desc_smp_init(desc + i, node);
		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
	}
	return arch_early_irq_init();
}

struct irq_desc *irq_to_desc(unsigned int irq)
{
	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
}

struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
{
	return irq_to_desc(irq);
}

static void free_desc(unsigned int irq)
{
	dynamic_irq_cleanup(irq);
}

static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
{
#if defined(CONFIG_KSTAT_IRQS_ONDEMAND)
	struct irq_desc *desc;
	unsigned int i;

	for (i = 0; i < cnt; i++) {
		desc = irq_to_desc(start + i);
		if (desc && !desc->kstat_irqs) {
			unsigned int __percpu *stats = alloc_percpu(unsigned int);

			if (!stats)
				return -1;
			if (cmpxchg(&desc->kstat_irqs, NULL, stats) != NULL)
				free_percpu(stats);
		}
	}
#endif
	return start;
}
#endif /* !CONFIG_SPARSE_IRQ */

/* Dynamic interrupt handling */

/**
 * irq_free_descs - free irq descriptors
 * @from:	Start of descriptor range
 * @cnt:	Number of consecutive irqs to free
 */
void irq_free_descs(unsigned int from, unsigned int cnt)
{
	int i;

	if (from >= nr_irqs || (from + cnt) > nr_irqs)
		return;

	for (i = 0; i < cnt; i++)
		free_desc(from + i);

	mutex_lock(&sparse_irq_lock);
	bitmap_clear(allocated_irqs, from, cnt);
	mutex_unlock(&sparse_irq_lock);
}

/**
 * irq_alloc_descs - allocate and initialize a range of irq descriptors
 * @irq:	Allocate for specific irq number if irq >= 0
 * @from:	Start the search from this irq number
 * @cnt:	Number of consecutive irqs to allocate.
 * @node:	Preferred node on which the irq descriptor should be allocated
 *
 * Returns the first irq number or error code
 */
int __ref
irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
{
	int start, ret;

	if (!cnt)
		return -EINVAL;

	mutex_lock(&sparse_irq_lock);

	start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
	ret = -EEXIST;
	if (irq >=0 && start != irq)
		goto err;

	ret = -ENOMEM;
	if (start >= nr_irqs)
		goto err;

	bitmap_set(allocated_irqs, start, cnt);
	mutex_unlock(&sparse_irq_lock);
	return alloc_descs(start, cnt, node);

err:
	mutex_unlock(&sparse_irq_lock);
	return ret;
}

/**
 * irq_reserve_irqs - mark irqs allocated
 * @from:	mark from irq number
 * @cnt:	number of irqs to mark
 *
 * Returns 0 on success or an appropriate error code
 */
int irq_reserve_irqs(unsigned int from, unsigned int cnt)
{
	unsigned int start;
	int ret = 0;

	if (!cnt || (from + cnt) > nr_irqs)
		return -EINVAL;

	mutex_lock(&sparse_irq_lock);
	start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
	if (start == from)
		bitmap_set(allocated_irqs, start, cnt);
	else
		ret = -EEXIST;
	mutex_unlock(&sparse_irq_lock);
	return ret;
}

/**
 * irq_get_next_irq - get next allocated irq number
 * @offset:	where to start the search
 *
 * Returns next irq number after offset or nr_irqs if none is found.
 */
unsigned int irq_get_next_irq(unsigned int offset)
{
	return find_next_bit(allocated_irqs, nr_irqs, offset);
}

/**
 * dynamic_irq_cleanup - cleanup a dynamically allocated irq
 * @irq:	irq number to initialize
 */
void dynamic_irq_cleanup(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);
	unsigned long flags;

	raw_spin_lock_irqsave(&desc->lock, flags);
	desc_set_defaults(irq, desc, desc_node(desc));
	raw_spin_unlock_irqrestore(&desc->lock, flags);
}

unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
{
	struct irq_desc *desc = irq_to_desc(irq);

	return desc && desc->kstat_irqs ?
			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
}

#ifdef CONFIG_GENERIC_HARDIRQS
unsigned int kstat_irqs(unsigned int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);
	int cpu;
	int sum = 0;

	if (!desc || !desc->kstat_irqs)
		return 0;
	for_each_possible_cpu(cpu)
		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
	return sum;
}
#endif /* CONFIG_GENERIC_HARDIRQS */
Commit	Line	Data
3795de23 TG	1	/*
	2	* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
	3	* Copyright (C) 2005-2006, Thomas Gleixner, Russell King
	4	*
	5	* This file contains the interrupt descriptor management code
	6	*
	7	* Detailed information is available in Documentation/DocBook/genericirq
	8	*
	9	*/
	10	#include <linux/irq.h>
	11	#include <linux/slab.h>
	12	#include <linux/module.h>
	13	#include <linux/interrupt.h>
	14	#include <linux/kernel_stat.h>
	15	#include <linux/radix-tree.h>
1f5a5b87	16	#include <linux/bitmap.h>
3795de23 TG	17
	18	#include "internals.h"
	19
	20	/*
	21	* lockdep: we want to handle all irq_desc locks as a single lock-class:
	22	*/
78f90d91	23	static struct lock_class_key irq_desc_lock_class;
3795de23 TG	24
	25	#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
	26	static void __init init_irq_default_affinity(void)
	27	{
	28	alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
	29	cpumask_setall(irq_default_affinity);
	30	}
	31	#else
	32	static void __init init_irq_default_affinity(void)
	33	{
	34	}
	35	#endif
	36
1f5a5b87 TG	37	#ifdef CONFIG_SMP
	38	static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
	39	{
	40	if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
	41	return -ENOMEM;
	42
	43	#ifdef CONFIG_GENERIC_PENDING_IRQ
	44	if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
	45	free_cpumask_var(desc->irq_data.affinity);
	46	return -ENOMEM;
	47	}
	48	#endif
	49	return 0;
	50	}
	51
	52	static void desc_smp_init(struct irq_desc *desc, int node)
	53	{
aa99ec0f	54	desc->irq_data.node = node;
1f5a5b87	55	cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
b7b29338 TG	56	#ifdef CONFIG_GENERIC_PENDING_IRQ
	57	cpumask_clear(desc->pending_mask);
	58	#endif
	59	}
	60
	61	static inline int desc_node(struct irq_desc *desc)
	62	{
	63	return desc->irq_data.node;
1f5a5b87 TG	64	}
	65
	66	#else
	67	static inline int
	68	alloc_masks(struct irq_desc *desc, gfp_t gfp, int node) { return 0; }
	69	static inline void desc_smp_init(struct irq_desc *desc, int node) { }
b7b29338	70	static inline int desc_node(struct irq_desc *desc) { return 0; }
1f5a5b87 TG	71	#endif
	72
	73	static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node)
	74	{
6c9ae009 ED	75	int cpu;
6c9ae009 ED	76
1f5a5b87 TG	77	desc->irq_data.irq = irq;
	78	desc->irq_data.chip = &no_irq_chip;
	79	desc->irq_data.chip_data = NULL;
	80	desc->irq_data.handler_data = NULL;
	81	desc->irq_data.msi_desc = NULL;
	82	desc->status = IRQ_DEFAULT_INIT_FLAGS;
	83	desc->handle_irq = handle_bad_irq;
	84	desc->depth = 1;
b7b29338 TG	85	desc->irq_count = 0;
b7b29338 TG	86	desc->irqs_unhandled = 0;
1f5a5b87	87	desc->name = NULL;
6c9ae009 ED	88	for_each_possible_cpu(cpu)
6c9ae009 ED	89	*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
1f5a5b87 TG	90	desc_smp_init(desc, node);
	91	}
	92
3795de23 TG	93	int nr_irqs = NR_IRQS;
	94	EXPORT_SYMBOL_GPL(nr_irqs);
	95
a05a900a	96	static DEFINE_MUTEX(sparse_irq_lock);
1f5a5b87 TG	97	static DECLARE_BITMAP(allocated_irqs, NR_IRQS);
1f5a5b87 TG	98
3795de23 TG	99	#ifdef CONFIG_SPARSE_IRQ
3795de23 TG	100
baa0d233	101	static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
3795de23	102
1f5a5b87	103	static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
3795de23 TG	104	{
	105	radix_tree_insert(&irq_desc_tree, irq, desc);
	106	}
	107
	108	struct irq_desc *irq_to_desc(unsigned int irq)
	109	{
	110	return radix_tree_lookup(&irq_desc_tree, irq);
	111	}
	112
1f5a5b87 TG	113	static void delete_irq_desc(unsigned int irq)
	114	{
	115	radix_tree_delete(&irq_desc_tree, irq);
	116	}
	117
	118	#ifdef CONFIG_SMP
	119	static void free_masks(struct irq_desc *desc)
	120	{
	121	#ifdef CONFIG_GENERIC_PENDING_IRQ
	122	free_cpumask_var(desc->pending_mask);
	123	#endif
c0a19ebc	124	free_cpumask_var(desc->irq_data.affinity);
1f5a5b87 TG	125	}
	126	#else
	127	static inline void free_masks(struct irq_desc *desc) { }
	128	#endif
	129
	130	static struct irq_desc *alloc_desc(int irq, int node)
	131	{
	132	struct irq_desc *desc;
baa0d233	133	gfp_t gfp = GFP_KERNEL;
1f5a5b87 TG	134
	135	desc = kzalloc_node(sizeof(*desc), gfp, node);
	136	if (!desc)
	137	return NULL;
	138	/* allocate based on nr_cpu_ids */
6c9ae009	139	desc->kstat_irqs = alloc_percpu(unsigned int);
1f5a5b87 TG	140	if (!desc->kstat_irqs)
	141	goto err_desc;
	142
	143	if (alloc_masks(desc, gfp, node))
	144	goto err_kstat;
	145
	146	raw_spin_lock_init(&desc->lock);
	147	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
	148
	149	desc_set_defaults(irq, desc, node);
	150
	151	return desc;
	152
	153	err_kstat:
6c9ae009	154	free_percpu(desc->kstat_irqs);
1f5a5b87 TG	155	err_desc:
	156	kfree(desc);
	157	return NULL;
	158	}
	159
	160	static void free_desc(unsigned int irq)
	161	{
	162	struct irq_desc *desc = irq_to_desc(irq);
1f5a5b87	163
13bfe99e TG	164	unregister_irq_proc(irq, desc);
13bfe99e TG	165
a05a900a	166	mutex_lock(&sparse_irq_lock);
1f5a5b87	167	delete_irq_desc(irq);
a05a900a	168	mutex_unlock(&sparse_irq_lock);
1f5a5b87 TG	169
1f5a5b87 TG	170	free_masks(desc);
6c9ae009	171	free_percpu(desc->kstat_irqs);
1f5a5b87 TG	172	kfree(desc);
	173	}
	174
	175	static int alloc_descs(unsigned int start, unsigned int cnt, int node)
	176	{
	177	struct irq_desc *desc;
1f5a5b87 TG	178	int i;
	179
	180	for (i = 0; i < cnt; i++) {
	181	desc = alloc_desc(start + i, node);
	182	if (!desc)
	183	goto err;
a05a900a	184	mutex_lock(&sparse_irq_lock);
1f5a5b87	185	irq_insert_desc(start + i, desc);
a05a900a	186	mutex_unlock(&sparse_irq_lock);
1f5a5b87 TG	187	}
	188	return start;
	189
	190	err:
	191	for (i--; i >= 0; i--)
	192	free_desc(start + i);
	193
a05a900a	194	mutex_lock(&sparse_irq_lock);
1f5a5b87	195	bitmap_clear(allocated_irqs, start, cnt);
a05a900a	196	mutex_unlock(&sparse_irq_lock);
1f5a5b87 TG	197	return -ENOMEM;
	198	}
	199
aa99ec0f TG	200	struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
	201	{
	202	int res = irq_alloc_descs(irq, irq, 1, node);
3795de23	203
aa99ec0f TG	204	if (res == -EEXIST \|\| res == irq)
	205	return irq_to_desc(irq);
	206	return NULL;
	207	}
3795de23 TG	208
	209	int __init early_irq_init(void)
	210	{
b683de2b	211	int i, initcnt, node = first_online_node;
3795de23	212	struct irq_desc *desc;
3795de23 TG	213
	214	init_irq_default_affinity();
	215
b683de2b TG	216	/* Let arch update nr_irqs and return the nr of preallocated irqs */
	217	initcnt = arch_probe_nr_irqs();
	218	printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
3795de23	219
b683de2b	220	for (i = 0; i < initcnt; i++) {
aa99ec0f TG	221	desc = alloc_desc(i, node);
	222	set_bit(i, allocated_irqs);
	223	irq_insert_desc(i, desc);
3795de23	224	}
3795de23 TG	225	return arch_early_irq_init();
	226	}
	227
3795de23 TG	228	#else /* !CONFIG_SPARSE_IRQ */
	229
	230	struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
	231	[0 ... NR_IRQS-1] = {
1318a481	232	.status = IRQ_DEFAULT_INIT_FLAGS,
3795de23 TG	233	.handle_irq = handle_bad_irq,
	234	.depth = 1,
	235	.lock = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
	236	}
	237	};
	238
3795de23 TG	239	int __init early_irq_init(void)
3795de23 TG	240	{
aa99ec0f	241	int count, i, node = first_online_node;
3795de23	242	struct irq_desc *desc;
3795de23 TG	243
	244	init_irq_default_affinity();
	245
	246	printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
	247
	248	desc = irq_desc;
	249	count = ARRAY_SIZE(irq_desc);
	250
	251	for (i = 0; i < count; i++) {
	252	desc[i].irq_data.irq = i;
	253	desc[i].irq_data.chip = &no_irq_chip;
6c9ae009 ED	254	/* TODO : do this allocation on-demand ... */
6c9ae009 ED	255	desc[i].kstat_irqs = alloc_percpu(unsigned int);
aa99ec0f TG	256	alloc_masks(desc + i, GFP_KERNEL, node);
aa99ec0f TG	257	desc_smp_init(desc + i, node);
154cd387	258	lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
3795de23 TG	259	}
	260	return arch_early_irq_init();
	261	}
	262
	263	struct irq_desc *irq_to_desc(unsigned int irq)
	264	{
	265	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
	266	}
	267
	268	struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
	269	{
	270	return irq_to_desc(irq);
	271	}
1f5a5b87	272
1f5a5b87 TG	273	static void free_desc(unsigned int irq)
1f5a5b87 TG	274	{
b7b29338	275	dynamic_irq_cleanup(irq);
1f5a5b87 TG	276	}
	277
	278	static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
	279	{
6c9ae009 ED	280	#if defined(CONFIG_KSTAT_IRQS_ONDEMAND)
	281	struct irq_desc *desc;
	282	unsigned int i;
	283
	284	for (i = 0; i < cnt; i++) {
	285	desc = irq_to_desc(start + i);
	286	if (desc && !desc->kstat_irqs) {
	287	unsigned int __percpu *stats = alloc_percpu(unsigned int);
	288
	289	if (!stats)
	290	return -1;
	291	if (cmpxchg(&desc->kstat_irqs, NULL, stats) != NULL)
	292	free_percpu(stats);
	293	}
	294	}
	295	#endif
1f5a5b87 TG	296	return start;
1f5a5b87 TG	297	}
3795de23 TG	298	#endif /* !CONFIG_SPARSE_IRQ */
3795de23 TG	299
1f5a5b87 TG	300	/* Dynamic interrupt handling */
	301
	302	/**
	303	* irq_free_descs - free irq descriptors
	304	* @from: Start of descriptor range
	305	* @cnt: Number of consecutive irqs to free
	306	*/
	307	void irq_free_descs(unsigned int from, unsigned int cnt)
	308	{
1f5a5b87 TG	309	int i;
	310
	311	if (from >= nr_irqs \|\| (from + cnt) > nr_irqs)
	312	return;
	313
	314	for (i = 0; i < cnt; i++)
	315	free_desc(from + i);
	316
a05a900a	317	mutex_lock(&sparse_irq_lock);
1f5a5b87	318	bitmap_clear(allocated_irqs, from, cnt);
a05a900a	319	mutex_unlock(&sparse_irq_lock);
1f5a5b87 TG	320	}
	321
	322	/**
	323	* irq_alloc_descs - allocate and initialize a range of irq descriptors
	324	* @irq: Allocate for specific irq number if irq >= 0
	325	* @from: Start the search from this irq number
	326	* @cnt: Number of consecutive irqs to allocate.
	327	* @node: Preferred node on which the irq descriptor should be allocated
	328	*
	329	* Returns the first irq number or error code
	330	*/
	331	int __ref
	332	irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
	333	{
1f5a5b87 TG	334	int start, ret;
	335
	336	if (!cnt)
	337	return -EINVAL;
	338
a05a900a	339	mutex_lock(&sparse_irq_lock);
1f5a5b87 TG	340
	341	start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
	342	ret = -EEXIST;
	343	if (irq >=0 && start != irq)
	344	goto err;
	345
	346	ret = -ENOMEM;
	347	if (start >= nr_irqs)
	348	goto err;
	349
	350	bitmap_set(allocated_irqs, start, cnt);
a05a900a	351	mutex_unlock(&sparse_irq_lock);
1f5a5b87 TG	352	return alloc_descs(start, cnt, node);
	353
	354	err:
a05a900a	355	mutex_unlock(&sparse_irq_lock);
1f5a5b87 TG	356	return ret;
	357	}
	358
06f6c339 TG	359	/**
	360	* irq_reserve_irqs - mark irqs allocated
	361	* @from: mark from irq number
	362	* @cnt: number of irqs to mark
	363	*
	364	* Returns 0 on success or an appropriate error code
	365	*/
	366	int irq_reserve_irqs(unsigned int from, unsigned int cnt)
	367	{
06f6c339 TG	368	unsigned int start;
	369	int ret = 0;
	370
	371	if (!cnt \|\| (from + cnt) > nr_irqs)
	372	return -EINVAL;
	373
a05a900a	374	mutex_lock(&sparse_irq_lock);
06f6c339 TG	375	start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
	376	if (start == from)
	377	bitmap_set(allocated_irqs, start, cnt);
	378	else
	379	ret = -EEXIST;
a05a900a	380	mutex_unlock(&sparse_irq_lock);
06f6c339 TG	381	return ret;
	382	}
	383
a98d24b7 TG	384	/**
	385	* irq_get_next_irq - get next allocated irq number
	386	* @offset: where to start the search
	387	*
	388	* Returns next irq number after offset or nr_irqs if none is found.
	389	*/
	390	unsigned int irq_get_next_irq(unsigned int offset)
	391	{
	392	return find_next_bit(allocated_irqs, nr_irqs, offset);
	393	}
	394
b7b29338 TG	395	/**
	396	* dynamic_irq_cleanup - cleanup a dynamically allocated irq
	397	* @irq: irq number to initialize
	398	*/
	399	void dynamic_irq_cleanup(unsigned int irq)
3795de23	400	{
b7b29338 TG	401	struct irq_desc *desc = irq_to_desc(irq);
	402	unsigned long flags;
	403
	404	raw_spin_lock_irqsave(&desc->lock, flags);
	405	desc_set_defaults(irq, desc, desc_node(desc));
	406	raw_spin_unlock_irqrestore(&desc->lock, flags);
3795de23 TG	407	}
3795de23 TG	408
3795de23 TG	409	unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
	410	{
	411	struct irq_desc *desc = irq_to_desc(irq);
6c9ae009 ED	412
	413	return desc && desc->kstat_irqs ?
	414	*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
3795de23	415	}
478735e3 KH	416
	417	#ifdef CONFIG_GENERIC_HARDIRQS
	418	unsigned int kstat_irqs(unsigned int irq)
	419	{
	420	struct irq_desc *desc = irq_to_desc(irq);
	421	int cpu;
	422	int sum = 0;
	423
6c9ae009	424	if (!desc \|\| !desc->kstat_irqs)
478735e3 KH	425	return 0;
478735e3 KH	426	for_each_possible_cpu(cpu)
6c9ae009	427	sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
478735e3 KH	428	return sum;
	429	}
	430	#endif /* CONFIG_GENERIC_HARDIRQS */