aboutsummaryrefslogtreecommitdiff
path: root/drivers/sh/intc/virq.c
blob: 1e6e2d0353ea52987e6ef25a5baf42173c0cea03 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
/*
 * 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_handler_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)irq_get_handler_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);

		irq_set_chip_and_handler_name(irq, irq_get_chip(entry->pirq),
					      handle_simple_irq, "virq");
		irq_set_chip_data(irq, irq_get_chip_data(entry->pirq));

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

		/*
		 * Set the virtual IRQ as non-threadable.
		 */
		irq_set_nothread(irq);

		irq_set_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);
}