Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
[firefly-linux-kernel-4.4.55.git] / kernel / irq / irqdesc.c
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/export.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/radix-tree.h>
16 #include <linux/bitmap.h>
17
18 #include "internals.h"
19
20 /*
21  * lockdep: we want to handle all irq_desc locks as a single lock-class:
22  */
23 static struct lock_class_key irq_desc_lock_class;
24
25 #if defined(CONFIG_SMP)
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
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 {
54         desc->irq_data.node = node;
55         cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
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;
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) { }
70 static inline int desc_node(struct irq_desc *desc) { return 0; }
71 #endif
72
73 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
74                 struct module *owner)
75 {
76         int cpu;
77
78         desc->irq_data.irq = irq;
79         desc->irq_data.chip = &no_irq_chip;
80         desc->irq_data.chip_data = NULL;
81         desc->irq_data.handler_data = NULL;
82         desc->irq_data.msi_desc = NULL;
83         irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
84         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
85         desc->handle_irq = handle_bad_irq;
86         desc->depth = 1;
87         desc->irq_count = 0;
88         desc->irqs_unhandled = 0;
89         desc->name = NULL;
90         desc->owner = owner;
91         for_each_possible_cpu(cpu)
92                 *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
93         desc_smp_init(desc, node);
94 }
95
96 int nr_irqs = NR_IRQS;
97 EXPORT_SYMBOL_GPL(nr_irqs);
98
99 static DEFINE_MUTEX(sparse_irq_lock);
100 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
101
102 #ifdef CONFIG_SPARSE_IRQ
103
104 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
105
106 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
107 {
108         radix_tree_insert(&irq_desc_tree, irq, desc);
109 }
110
111 struct irq_desc *irq_to_desc(unsigned int irq)
112 {
113         return radix_tree_lookup(&irq_desc_tree, irq);
114 }
115 EXPORT_SYMBOL(irq_to_desc);
116
117 static void delete_irq_desc(unsigned int irq)
118 {
119         radix_tree_delete(&irq_desc_tree, irq);
120 }
121
122 #ifdef CONFIG_SMP
123 static void free_masks(struct irq_desc *desc)
124 {
125 #ifdef CONFIG_GENERIC_PENDING_IRQ
126         free_cpumask_var(desc->pending_mask);
127 #endif
128         free_cpumask_var(desc->irq_data.affinity);
129 }
130 #else
131 static inline void free_masks(struct irq_desc *desc) { }
132 #endif
133
134 static struct irq_desc *alloc_desc(int irq, int node, struct module *owner)
135 {
136         struct irq_desc *desc;
137         gfp_t gfp = GFP_KERNEL;
138
139         desc = kzalloc_node(sizeof(*desc), gfp, node);
140         if (!desc)
141                 return NULL;
142         /* allocate based on nr_cpu_ids */
143         desc->kstat_irqs = alloc_percpu(unsigned int);
144         if (!desc->kstat_irqs)
145                 goto err_desc;
146
147         if (alloc_masks(desc, gfp, node))
148                 goto err_kstat;
149
150         raw_spin_lock_init(&desc->lock);
151         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
152
153         desc_set_defaults(irq, desc, node, owner);
154
155         return desc;
156
157 err_kstat:
158         free_percpu(desc->kstat_irqs);
159 err_desc:
160         kfree(desc);
161         return NULL;
162 }
163
164 static void free_desc(unsigned int irq)
165 {
166         struct irq_desc *desc = irq_to_desc(irq);
167
168         unregister_irq_proc(irq, desc);
169
170         mutex_lock(&sparse_irq_lock);
171         delete_irq_desc(irq);
172         mutex_unlock(&sparse_irq_lock);
173
174         free_masks(desc);
175         free_percpu(desc->kstat_irqs);
176         kfree(desc);
177 }
178
179 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
180                        struct module *owner)
181 {
182         struct irq_desc *desc;
183         int i;
184
185         for (i = 0; i < cnt; i++) {
186                 desc = alloc_desc(start + i, node, owner);
187                 if (!desc)
188                         goto err;
189                 mutex_lock(&sparse_irq_lock);
190                 irq_insert_desc(start + i, desc);
191                 mutex_unlock(&sparse_irq_lock);
192         }
193         return start;
194
195 err:
196         for (i--; i >= 0; i--)
197                 free_desc(start + i);
198
199         mutex_lock(&sparse_irq_lock);
200         bitmap_clear(allocated_irqs, start, cnt);
201         mutex_unlock(&sparse_irq_lock);
202         return -ENOMEM;
203 }
204
205 static int irq_expand_nr_irqs(unsigned int nr)
206 {
207         if (nr > IRQ_BITMAP_BITS)
208                 return -ENOMEM;
209         nr_irqs = nr;
210         return 0;
211 }
212
213 int __init early_irq_init(void)
214 {
215         int i, initcnt, node = first_online_node;
216         struct irq_desc *desc;
217
218         init_irq_default_affinity();
219
220         /* Let arch update nr_irqs and return the nr of preallocated irqs */
221         initcnt = arch_probe_nr_irqs();
222         printk(KERN_INFO "NR_IRQS:%d nr_irqs:%d %d\n", NR_IRQS, nr_irqs, initcnt);
223
224         if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
225                 nr_irqs = IRQ_BITMAP_BITS;
226
227         if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
228                 initcnt = IRQ_BITMAP_BITS;
229
230         if (initcnt > nr_irqs)
231                 nr_irqs = initcnt;
232
233         for (i = 0; i < initcnt; i++) {
234                 desc = alloc_desc(i, node, NULL);
235                 set_bit(i, allocated_irqs);
236                 irq_insert_desc(i, desc);
237         }
238         return arch_early_irq_init();
239 }
240
241 #else /* !CONFIG_SPARSE_IRQ */
242
243 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
244         [0 ... NR_IRQS-1] = {
245                 .handle_irq     = handle_bad_irq,
246                 .depth          = 1,
247                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
248         }
249 };
250
251 int __init early_irq_init(void)
252 {
253         int count, i, node = first_online_node;
254         struct irq_desc *desc;
255
256         init_irq_default_affinity();
257
258         printk(KERN_INFO "NR_IRQS:%d\n", NR_IRQS);
259
260         desc = irq_desc;
261         count = ARRAY_SIZE(irq_desc);
262
263         for (i = 0; i < count; i++) {
264                 desc[i].kstat_irqs = alloc_percpu(unsigned int);
265                 alloc_masks(&desc[i], GFP_KERNEL, node);
266                 raw_spin_lock_init(&desc[i].lock);
267                 lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
268                 desc_set_defaults(i, &desc[i], node, NULL);
269         }
270         return arch_early_irq_init();
271 }
272
273 struct irq_desc *irq_to_desc(unsigned int irq)
274 {
275         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
276 }
277 EXPORT_SYMBOL(irq_to_desc);
278
279 static void free_desc(unsigned int irq)
280 {
281         dynamic_irq_cleanup(irq);
282 }
283
284 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
285                               struct module *owner)
286 {
287         u32 i;
288
289         for (i = 0; i < cnt; i++) {
290                 struct irq_desc *desc = irq_to_desc(start + i);
291
292                 desc->owner = owner;
293         }
294         return start;
295 }
296
297 static int irq_expand_nr_irqs(unsigned int nr)
298 {
299         return -ENOMEM;
300 }
301
302 #endif /* !CONFIG_SPARSE_IRQ */
303
304 /**
305  * generic_handle_irq - Invoke the handler for a particular irq
306  * @irq:        The irq number to handle
307  *
308  */
309 int generic_handle_irq(unsigned int irq)
310 {
311         struct irq_desc *desc = irq_to_desc(irq);
312
313         if (!desc)
314                 return -EINVAL;
315         generic_handle_irq_desc(irq, desc);
316         return 0;
317 }
318 EXPORT_SYMBOL_GPL(generic_handle_irq);
319
320 /* Dynamic interrupt handling */
321
322 /**
323  * irq_free_descs - free irq descriptors
324  * @from:       Start of descriptor range
325  * @cnt:        Number of consecutive irqs to free
326  */
327 void irq_free_descs(unsigned int from, unsigned int cnt)
328 {
329         int i;
330
331         if (from >= nr_irqs || (from + cnt) > nr_irqs)
332                 return;
333
334         for (i = 0; i < cnt; i++)
335                 free_desc(from + i);
336
337         mutex_lock(&sparse_irq_lock);
338         bitmap_clear(allocated_irqs, from, cnt);
339         mutex_unlock(&sparse_irq_lock);
340 }
341 EXPORT_SYMBOL_GPL(irq_free_descs);
342
343 /**
344  * irq_alloc_descs - allocate and initialize a range of irq descriptors
345  * @irq:        Allocate for specific irq number if irq >= 0
346  * @from:       Start the search from this irq number
347  * @cnt:        Number of consecutive irqs to allocate.
348  * @node:       Preferred node on which the irq descriptor should be allocated
349  * @owner:      Owning module (can be NULL)
350  *
351  * Returns the first irq number or error code
352  */
353 int __ref
354 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
355                   struct module *owner)
356 {
357         int start, ret;
358
359         if (!cnt)
360                 return -EINVAL;
361
362         if (irq >= 0) {
363                 if (from > irq)
364                         return -EINVAL;
365                 from = irq;
366         }
367
368         mutex_lock(&sparse_irq_lock);
369
370         start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
371                                            from, cnt, 0);
372         ret = -EEXIST;
373         if (irq >=0 && start != irq)
374                 goto err;
375
376         if (start + cnt > nr_irqs) {
377                 ret = irq_expand_nr_irqs(start + cnt);
378                 if (ret)
379                         goto err;
380         }
381
382         bitmap_set(allocated_irqs, start, cnt);
383         mutex_unlock(&sparse_irq_lock);
384         return alloc_descs(start, cnt, node, owner);
385
386 err:
387         mutex_unlock(&sparse_irq_lock);
388         return ret;
389 }
390 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
391
392 /**
393  * irq_reserve_irqs - mark irqs allocated
394  * @from:       mark from irq number
395  * @cnt:        number of irqs to mark
396  *
397  * Returns 0 on success or an appropriate error code
398  */
399 int irq_reserve_irqs(unsigned int from, unsigned int cnt)
400 {
401         unsigned int start;
402         int ret = 0;
403
404         if (!cnt || (from + cnt) > nr_irqs)
405                 return -EINVAL;
406
407         mutex_lock(&sparse_irq_lock);
408         start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
409         if (start == from)
410                 bitmap_set(allocated_irqs, start, cnt);
411         else
412                 ret = -EEXIST;
413         mutex_unlock(&sparse_irq_lock);
414         return ret;
415 }
416
417 /**
418  * irq_get_next_irq - get next allocated irq number
419  * @offset:     where to start the search
420  *
421  * Returns next irq number after offset or nr_irqs if none is found.
422  */
423 unsigned int irq_get_next_irq(unsigned int offset)
424 {
425         return find_next_bit(allocated_irqs, nr_irqs, offset);
426 }
427
428 struct irq_desc *
429 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
430                     unsigned int check)
431 {
432         struct irq_desc *desc = irq_to_desc(irq);
433
434         if (desc) {
435                 if (check & _IRQ_DESC_CHECK) {
436                         if ((check & _IRQ_DESC_PERCPU) &&
437                             !irq_settings_is_per_cpu_devid(desc))
438                                 return NULL;
439
440                         if (!(check & _IRQ_DESC_PERCPU) &&
441                             irq_settings_is_per_cpu_devid(desc))
442                                 return NULL;
443                 }
444
445                 if (bus)
446                         chip_bus_lock(desc);
447                 raw_spin_lock_irqsave(&desc->lock, *flags);
448         }
449         return desc;
450 }
451
452 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
453 {
454         raw_spin_unlock_irqrestore(&desc->lock, flags);
455         if (bus)
456                 chip_bus_sync_unlock(desc);
457 }
458
459 int irq_set_percpu_devid(unsigned int irq)
460 {
461         struct irq_desc *desc = irq_to_desc(irq);
462
463         if (!desc)
464                 return -EINVAL;
465
466         if (desc->percpu_enabled)
467                 return -EINVAL;
468
469         desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
470
471         if (!desc->percpu_enabled)
472                 return -ENOMEM;
473
474         irq_set_percpu_devid_flags(irq);
475         return 0;
476 }
477
478 /**
479  * dynamic_irq_cleanup - cleanup a dynamically allocated irq
480  * @irq:        irq number to initialize
481  */
482 void dynamic_irq_cleanup(unsigned int irq)
483 {
484         struct irq_desc *desc = irq_to_desc(irq);
485         unsigned long flags;
486
487         raw_spin_lock_irqsave(&desc->lock, flags);
488         desc_set_defaults(irq, desc, desc_node(desc), NULL);
489         raw_spin_unlock_irqrestore(&desc->lock, flags);
490 }
491
492 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
493 {
494         struct irq_desc *desc = irq_to_desc(irq);
495
496         return desc && desc->kstat_irqs ?
497                         *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
498 }
499
500 unsigned int kstat_irqs(unsigned int irq)
501 {
502         struct irq_desc *desc = irq_to_desc(irq);
503         int cpu;
504         int sum = 0;
505
506         if (!desc || !desc->kstat_irqs)
507                 return 0;
508         for_each_possible_cpu(cpu)
509                 sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
510         return sum;
511 }