drivers: sh: late disabling of clocks V2
[linux-3.10.git] / drivers / sh / intc / virq.c
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;
86         struct irq_data *data = irq_get_irq_data(irq);
87
88         /* scan for duplicates */
89         last = (struct intc_virq_list **)&data->handler_data;
90         for_each_virq(entry, data->handler_data) {
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 {
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_handler_data(data);
114         struct intc_desc_int *d = get_intc_desc(irq);
115
116         chip->irq_mask_ack(data);
117
118         for_each_virq(entry, vlist) {
119                 unsigned long addr, handle;
120
121                 handle = (unsigned long)irq_get_handler_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
128         chip->irq_unmask(data);
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;
218                 if (radix_tree_deref_retry(entry))
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                 irq_set_chip_and_handler_name(irq, irq_get_chip(entry->pirq),
233                                               handle_simple_irq, "virq");
234                 irq_set_chip_data(irq, irq_get_chip_data(entry->pirq));
235
236                 irq_set_handler_data(irq, (void *)entry->handle);
237
238                 /*
239                  * Set the virtual IRQ as non-threadable.
240                  */
241                 irq_set_nothread(irq);
242
243                 irq_set_chained_handler(entry->pirq, intc_virq_handler);
244                 add_virq_to_pirq(entry->pirq, irq);
245
246                 radix_tree_tag_clear(&d->tree, entry->enum_id,
247                                      INTC_TAG_VIRQ_NEEDS_ALLOC);
248                 radix_tree_replace_slot((void **)entries[i],
249                                         &intc_irq_xlate[irq]);
250         }
251
252         raw_spin_unlock_irqrestore(&d->lock, flags);
253 }
254
255 void __init intc_finalize(void)
256 {
257         struct intc_desc_int *d;
258
259         list_for_each_entry(d, &intc_list, list)
260                 if (radix_tree_tagged(&d->tree, INTC_TAG_VIRQ_NEEDS_ALLOC))
261                         intc_subgroup_map(d);
262 }