[mirror_ubuntu-bionic-kernel.git] / drivers / sh / intc / virq.c

/*
 * Support for virtual IRQ subgroups.
 *
 * Copyright (C) 2010  Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#define pr_fmt(fmt) "intc: " fmt

#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/list.h>
#include <linux/radix-tree.h>
#include <linux/spinlock.h>
#include "internals.h"

static struct intc_map_entry intc_irq_xlate[NR_IRQS];

struct intc_virq_list {
	unsigned int irq;
	struct intc_virq_list *next;
};

#define for_each_virq(entry, head) \
	for (entry = head; entry; entry = entry->next)

/*
 * Tags for the radix tree
 */
#define INTC_TAG_VIRQ_NEEDS_ALLOC	0

void intc_irq_xlate_set(unsigned int irq, intc_enum id, struct intc_desc_int *d)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&intc_big_lock, flags);
	intc_irq_xlate[irq].enum_id = id;
	intc_irq_xlate[irq].desc = d;
	raw_spin_unlock_irqrestore(&intc_big_lock, flags);
}

struct intc_map_entry *intc_irq_xlate_get(unsigned int irq)
{
	return intc_irq_xlate + irq;
}

int intc_irq_lookup(const char *chipname, intc_enum enum_id)
{
	struct intc_map_entry *ptr;
	struct intc_desc_int *d;
	int irq = -1;

	list_for_each_entry(d, &intc_list, list) {
		int tagged;

		if (strcmp(d->chip.name, chipname) != 0)
			continue;

		/*
		 * Catch early lookups for subgroup VIRQs that have not
		 * yet been allocated an IRQ. This already includes a
		 * fast-path out if the tree is untagged, so there is no
		 * need to explicitly test the root tree.
		 */
		tagged = radix_tree_tag_get(&d->tree, enum_id,
					    INTC_TAG_VIRQ_NEEDS_ALLOC);
		if (unlikely(tagged))
			break;

		ptr = radix_tree_lookup(&d->tree, enum_id);
		if (ptr) {
			irq = ptr - intc_irq_xlate;
			break;
		}
	}

	return irq;
}
EXPORT_SYMBOL_GPL(intc_irq_lookup);

static int add_virq_to_pirq(unsigned int irq, unsigned int virq)
{
	struct intc_virq_list **last, *entry;
	struct irq_data *data = irq_get_irq_data(irq);

	/* scan for duplicates */
	last = (struct intc_virq_list **)&data->handler_data;
	for_each_virq(entry, data->handler_data) {
		if (entry->irq == virq)
			return 0;
		last = &entry->next;
	}

	entry = kzalloc(sizeof(struct intc_virq_list), GFP_ATOMIC);
	if (!entry) {
		pr_err("can't allocate VIRQ mapping for %d\n", virq);
		return -ENOMEM;
	}

	entry->irq = virq;

	*last = entry;

	return 0;
}

static void intc_virq_handler(unsigned int irq, struct irq_desc *desc)
{
	struct irq_data *data = irq_get_irq_data(irq);
	struct irq_chip *chip = irq_data_get_irq_chip(data);
	struct intc_virq_list *entry, *vlist = irq_data_get_irq_data(data);
	struct intc_desc_int *d = get_intc_desc(irq);

	chip->irq_mask_ack(data);

	for_each_virq(entry, vlist) {
		unsigned long addr, handle;

		handle = (unsigned long)get_irq_data(entry->irq);
		addr = INTC_REG(d, _INTC_ADDR_E(handle), 0);

		if (intc_reg_fns[_INTC_FN(handle)](addr, handle, 0))
			generic_handle_irq(entry->irq);
	}

	chip->irq_unmask(data);
}

static unsigned long __init intc_subgroup_data(struct intc_subgroup *subgroup,
					       struct intc_desc_int *d,
					       unsigned int index)
{
	unsigned int fn = REG_FN_TEST_BASE + (subgroup->reg_width >> 3) - 1;

	return _INTC_MK(fn, MODE_ENABLE_REG, intc_get_reg(d, subgroup->reg),
			0, 1, (subgroup->reg_width - 1) - index);
}

static void __init intc_subgroup_init_one(struct intc_desc *desc,
					  struct intc_desc_int *d,
					  struct intc_subgroup *subgroup)
{
	struct intc_map_entry *mapped;
	unsigned int pirq;
	unsigned long flags;
	int i;

	mapped = radix_tree_lookup(&d->tree, subgroup->parent_id);
	if (!mapped) {
		WARN_ON(1);
		return;
	}

	pirq = mapped - intc_irq_xlate;

	raw_spin_lock_irqsave(&d->lock, flags);

	for (i = 0; i < ARRAY_SIZE(subgroup->enum_ids); i++) {
		struct intc_subgroup_entry *entry;
		int err;

		if (!subgroup->enum_ids[i])
			continue;

		entry = kmalloc(sizeof(*entry), GFP_NOWAIT);
		if (!entry)
			break;

		entry->pirq = pirq;
		entry->enum_id = subgroup->enum_ids[i];
		entry->handle = intc_subgroup_data(subgroup, d, i);

		err = radix_tree_insert(&d->tree, entry->enum_id, entry);
		if (unlikely(err < 0))
			break;

		radix_tree_tag_set(&d->tree, entry->enum_id,
				   INTC_TAG_VIRQ_NEEDS_ALLOC);
	}

	raw_spin_unlock_irqrestore(&d->lock, flags);
}

void __init intc_subgroup_init(struct intc_desc *desc, struct intc_desc_int *d)
{
	int i;

	if (!desc->hw.subgroups)
		return;

	for (i = 0; i < desc->hw.nr_subgroups; i++)
		intc_subgroup_init_one(desc, d, desc->hw.subgroups + i);
}

static void __init intc_subgroup_map(struct intc_desc_int *d)
{
	struct intc_subgroup_entry *entries[32];
	unsigned long flags;
	unsigned int nr_found;
	int i;

	raw_spin_lock_irqsave(&d->lock, flags);

restart:
	nr_found = radix_tree_gang_lookup_tag_slot(&d->tree,
			(void ***)entries, 0, ARRAY_SIZE(entries),
			INTC_TAG_VIRQ_NEEDS_ALLOC);

	for (i = 0; i < nr_found; i++) {
		struct intc_subgroup_entry *entry;
		int irq;

		entry = radix_tree_deref_slot((void **)entries[i]);
		if (unlikely(!entry))
			continue;
		if (radix_tree_deref_retry(entry))
			goto restart;

		irq = create_irq();
		if (unlikely(irq < 0)) {
			pr_err("no more free IRQs, bailing..\n");
			break;
		}

		pr_info("Setting up a chained VIRQ from %d -> %d\n",
			irq, entry->pirq);

		intc_irq_xlate_set(irq, entry->enum_id, d);

		set_irq_chip_and_handler_name(irq, get_irq_chip(entry->pirq),
					      handle_simple_irq, "virq");
		set_irq_chip_data(irq, get_irq_chip_data(entry->pirq));

		set_irq_data(irq, (void *)entry->handle);

		set_irq_chained_handler(entry->pirq, intc_virq_handler);
		add_virq_to_pirq(entry->pirq, irq);

		radix_tree_tag_clear(&d->tree, entry->enum_id,
				     INTC_TAG_VIRQ_NEEDS_ALLOC);
		radix_tree_replace_slot((void **)entries[i],
					&intc_irq_xlate[irq]);
	}

	raw_spin_unlock_irqrestore(&d->lock, flags);
}

void __init intc_finalize(void)
{
	struct intc_desc_int *d;

	list_for_each_entry(d, &intc_list, list)
		if (radix_tree_tagged(&d->tree, INTC_TAG_VIRQ_NEEDS_ALLOC))
			intc_subgroup_map(d);
}
Commit	Line	Data
2be6bb0c PM	1	/*
	2	* Support for virtual IRQ subgroups.
	3	*
	4	* Copyright (C) 2010 Paul Mundt
	5	*
	6	* This file is subject to the terms and conditions of the GNU General Public
	7	* License. See the file "COPYING" in the main directory of this archive
	8	* for more details.
	9	*/
	10	#define pr_fmt(fmt) "intc: " fmt
	11
	12	#include <linux/slab.h>
	13	#include <linux/irq.h>
	14	#include <linux/list.h>
	15	#include <linux/radix-tree.h>
	16	#include <linux/spinlock.h>
	17	#include "internals.h"
	18
	19	static struct intc_map_entry intc_irq_xlate[NR_IRQS];
	20
	21	struct intc_virq_list {
	22	unsigned int irq;
	23	struct intc_virq_list *next;
	24	};
	25
	26	#define for_each_virq(entry, head) \
	27	for (entry = head; entry; entry = entry->next)
	28
	29	/*
	30	* Tags for the radix tree
	31	*/
	32	#define INTC_TAG_VIRQ_NEEDS_ALLOC 0
	33
	34	void intc_irq_xlate_set(unsigned int irq, intc_enum id, struct intc_desc_int *d)
	35	{
	36	unsigned long flags;
	37
	38	raw_spin_lock_irqsave(&intc_big_lock, flags);
	39	intc_irq_xlate[irq].enum_id = id;
	40	intc_irq_xlate[irq].desc = d;
	41	raw_spin_unlock_irqrestore(&intc_big_lock, flags);
	42	}
	43
	44	struct intc_map_entry *intc_irq_xlate_get(unsigned int irq)
	45	{
	46	return intc_irq_xlate + irq;
	47	}
	48
	49	int intc_irq_lookup(const char *chipname, intc_enum enum_id)
	50	{
	51	struct intc_map_entry *ptr;
	52	struct intc_desc_int *d;
	53	int irq = -1;
	54
	55	list_for_each_entry(d, &intc_list, list) {
	56	int tagged;
	57
	58	if (strcmp(d->chip.name, chipname) != 0)
	59	continue;
	60
	61	/*
	62	* Catch early lookups for subgroup VIRQs that have not
	63	* yet been allocated an IRQ. This already includes a
	64	* fast-path out if the tree is untagged, so there is no
65	* need to explicitly test the root tree.
66	*/
67	tagged = radix_tree_tag_get(&d->tree, enum_id,
68	INTC_TAG_VIRQ_NEEDS_ALLOC);
69	if (unlikely(tagged))
70	break;
71
72	ptr = radix_tree_lookup(&d->tree, enum_id);
73	if (ptr) {
74	irq = ptr - intc_irq_xlate;
75	break;
76	}
77	}
78
79	return irq;
80	}
81	EXPORT_SYMBOL_GPL(intc_irq_lookup);
82
83	static int add_virq_to_pirq(unsigned int irq, unsigned int virq)
84	{
85	struct intc_virq_list *last, entry;
26599a94	86	struct irq_data *data = irq_get_irq_data(irq);
2be6bb0c PM	87
2be6bb0c PM	88	/* scan for duplicates */
26599a94 PM	89	last = (struct intc_virq_list **)&data->handler_data;
26599a94 PM	90	for_each_virq(entry, data->handler_data) {
2be6bb0c PM	91	if (entry->irq == virq)
	92	return 0;
	93	last = &entry->next;
	94	}
	95
	96	entry = kzalloc(sizeof(struct intc_virq_list), GFP_ATOMIC);
	97	if (!entry) {
	98	pr_err("can't allocate VIRQ mapping for %d\n", virq);
	99	return -ENOMEM;
	100	}
	101
	102	entry->irq = virq;
	103
	104	*last = entry;
	105
	106	return 0;
	107	}
	108
	109	static void intc_virq_handler(unsigned int irq, struct irq_desc *desc)
	110	{
26599a94 PM	111	struct irq_data *data = irq_get_irq_data(irq);
	112	struct irq_chip *chip = irq_data_get_irq_chip(data);
	113	struct intc_virq_list entry, vlist = irq_data_get_irq_data(data);
2be6bb0c PM	114	struct intc_desc_int *d = get_intc_desc(irq);
2be6bb0c PM	115
26599a94	116	chip->irq_mask_ack(data);
2be6bb0c PM	117
	118	for_each_virq(entry, vlist) {
	119	unsigned long addr, handle;
	120
	121	handle = (unsigned long)get_irq_data(entry->irq);
	122	addr = INTC_REG(d, _INTC_ADDR_E(handle), 0);
	123
	124	if (intc_reg_fns[_INTC_FN(handle)](addr, handle, 0))
	125	generic_handle_irq(entry->irq);
	126	}
	127
26599a94	128	chip->irq_unmask(data);
2be6bb0c PM	129	}
	130
	131	static unsigned long __init intc_subgroup_data(struct intc_subgroup *subgroup,
	132	struct intc_desc_int *d,
	133	unsigned int index)
	134	{
	135	unsigned int fn = REG_FN_TEST_BASE + (subgroup->reg_width >> 3) - 1;
	136
	137	return _INTC_MK(fn, MODE_ENABLE_REG, intc_get_reg(d, subgroup->reg),
	138	0, 1, (subgroup->reg_width - 1) - index);
	139	}
	140
	141	static void __init intc_subgroup_init_one(struct intc_desc *desc,
	142	struct intc_desc_int *d,
	143	struct intc_subgroup *subgroup)
	144	{
	145	struct intc_map_entry *mapped;
	146	unsigned int pirq;
	147	unsigned long flags;
	148	int i;
	149
	150	mapped = radix_tree_lookup(&d->tree, subgroup->parent_id);
	151	if (!mapped) {
	152	WARN_ON(1);
	153	return;
	154	}
	155
	156	pirq = mapped - intc_irq_xlate;
	157
	158	raw_spin_lock_irqsave(&d->lock, flags);
	159
	160	for (i = 0; i < ARRAY_SIZE(subgroup->enum_ids); i++) {
	161	struct intc_subgroup_entry *entry;
	162	int err;
	163
	164	if (!subgroup->enum_ids[i])
	165	continue;
	166
	167	entry = kmalloc(sizeof(*entry), GFP_NOWAIT);
	168	if (!entry)
	169	break;
	170
	171	entry->pirq = pirq;
	172	entry->enum_id = subgroup->enum_ids[i];
	173	entry->handle = intc_subgroup_data(subgroup, d, i);
	174
	175	err = radix_tree_insert(&d->tree, entry->enum_id, entry);
	176	if (unlikely(err < 0))
	177	break;
	178
	179	radix_tree_tag_set(&d->tree, entry->enum_id,
	180	INTC_TAG_VIRQ_NEEDS_ALLOC);
	181	}
	182
	183	raw_spin_unlock_irqrestore(&d->lock, flags);
	184	}
	185
	186	void __init intc_subgroup_init(struct intc_desc desc, struct intc_desc_int d)
	187	{
	188	int i;
	189
	190	if (!desc->hw.subgroups)
	191	return;
	192
193	for (i = 0; i < desc->hw.nr_subgroups; i++)
194	intc_subgroup_init_one(desc, d, desc->hw.subgroups + i);
195	}
196
197	static void __init intc_subgroup_map(struct intc_desc_int *d)
198	{
199	struct intc_subgroup_entry *entries[32];
200	unsigned long flags;
201	unsigned int nr_found;
202	int i;
203
204	raw_spin_lock_irqsave(&d->lock, flags);
205
206	restart:
207	nr_found = radix_tree_gang_lookup_tag_slot(&d->tree,
208	(void ***)entries, 0, ARRAY_SIZE(entries),
209	INTC_TAG_VIRQ_NEEDS_ALLOC);
210
211	for (i = 0; i < nr_found; i++) {
212	struct intc_subgroup_entry *entry;
213	int irq;
214
215	entry = radix_tree_deref_slot((void **)entries[i]);
216	if (unlikely(!entry))
217	continue;
6318af90	218	if (radix_tree_deref_retry(entry))
2be6bb0c PM	219	goto restart;
	220
	221	irq = create_irq();
	222	if (unlikely(irq < 0)) {
	223	pr_err("no more free IRQs, bailing..\n");
	224	break;
	225	}
	226
	227	pr_info("Setting up a chained VIRQ from %d -> %d\n",
	228	irq, entry->pirq);
	229
	230	intc_irq_xlate_set(irq, entry->enum_id, d);
	231
	232	set_irq_chip_and_handler_name(irq, get_irq_chip(entry->pirq),
	233	handle_simple_irq, "virq");
	234	set_irq_chip_data(irq, get_irq_chip_data(entry->pirq));
	235
	236	set_irq_data(irq, (void *)entry->handle);
	237
	238	set_irq_chained_handler(entry->pirq, intc_virq_handler);
	239	add_virq_to_pirq(entry->pirq, irq);
	240
	241	radix_tree_tag_clear(&d->tree, entry->enum_id,
	242	INTC_TAG_VIRQ_NEEDS_ALLOC);
	243	radix_tree_replace_slot((void **)entries[i],
	244	&intc_irq_xlate[irq]);
	245	}
	246
	247	raw_spin_unlock_irqrestore(&d->lock, flags);
	248	}
	249
	250	void __init intc_finalize(void)
	251	{
	252	struct intc_desc_int *d;
	253
	254	list_for_each_entry(d, &intc_list, list)
	255	if (radix_tree_tagged(&d->tree, INTC_TAG_VIRQ_NEEDS_ALLOC))
	256	intc_subgroup_map(d);
	257	}