Merge tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
[linux-2.6-block.git] / kernel / irq / proc.c
CommitLineData
1da177e4
LT
1/*
2 * linux/kernel/irq/proc.c
3 *
4 * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
5 *
6 * This file contains the /proc/irq/ handling code.
7 */
8
9#include <linux/irq.h>
5a0e3ad6 10#include <linux/gfp.h>
1da177e4 11#include <linux/proc_fs.h>
f18e439d 12#include <linux/seq_file.h>
1da177e4 13#include <linux/interrupt.h>
c78b9b65 14#include <linux/kernel_stat.h>
95c2b175 15#include <linux/mutex.h>
1da177e4 16
97a41e26
AB
17#include "internals.h"
18
c291ee62
TG
19/*
20 * Access rules:
21 *
22 * procfs protects read/write of /proc/irq/N/ files against a
23 * concurrent free of the interrupt descriptor. remove_proc_entry()
24 * immediately prevents new read/writes to happen and waits for
25 * already running read/write functions to complete.
26 *
27 * We remove the proc entries first and then delete the interrupt
28 * descriptor from the radix tree and free it. So it is guaranteed
29 * that irq_to_desc(N) is valid as long as the read/writes are
30 * permitted by procfs.
31 *
32 * The read from /proc/interrupts is a different problem because there
33 * is no protection. So the lookup and the access to irqdesc
34 * information must be protected by sparse_irq_lock.
35 */
4a733ee1 36static struct proc_dir_entry *root_irq_dir;
1da177e4
LT
37
38#ifdef CONFIG_SMP
39
4b060420 40static int show_irq_affinity(int type, struct seq_file *m, void *v)
1da177e4 41{
08678b08 42 struct irq_desc *desc = irq_to_desc((long)m->private);
9df872fa 43 const struct cpumask *mask = desc->irq_common_data.affinity;
42ee2b74
AK
44
45#ifdef CONFIG_GENERIC_PENDING_IRQ
f230b6d5 46 if (irqd_is_setaffinity_pending(&desc->irq_data))
7f7ace0c 47 mask = desc->pending_mask;
42ee2b74 48#endif
4b060420 49 if (type)
c1d7f03f 50 seq_printf(m, "%*pbl\n", cpumask_pr_args(mask));
4b060420 51 else
c1d7f03f 52 seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
f18e439d 53 return 0;
1da177e4
LT
54}
55
e7a297b0
PWJ
56static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
57{
58 struct irq_desc *desc = irq_to_desc((long)m->private);
59 unsigned long flags;
60 cpumask_var_t mask;
61
4308ad80 62 if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
e7a297b0
PWJ
63 return -ENOMEM;
64
65 raw_spin_lock_irqsave(&desc->lock, flags);
66 if (desc->affinity_hint)
67 cpumask_copy(mask, desc->affinity_hint);
e7a297b0
PWJ
68 raw_spin_unlock_irqrestore(&desc->lock, flags);
69
c1d7f03f 70 seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
e7a297b0
PWJ
71 free_cpumask_var(mask);
72
73 return 0;
74}
75
25d61578
JK
76#ifndef is_affinity_mask_valid
77#define is_affinity_mask_valid(val) 1
78#endif
79
1da177e4 80int no_irq_affinity;
4b060420
MT
81static int irq_affinity_proc_show(struct seq_file *m, void *v)
82{
83 return show_irq_affinity(0, m, v);
84}
85
86static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
87{
88 return show_irq_affinity(1, m, v);
89}
90
91
92static ssize_t write_irq_affinity(int type, struct file *file,
f18e439d 93 const char __user *buffer, size_t count, loff_t *pos)
1da177e4 94{
d9dda78b 95 unsigned int irq = (int)(long)PDE_DATA(file_inode(file));
0de26520 96 cpumask_var_t new_value;
f18e439d 97 int err;
1da177e4 98
bce43032 99 if (!irq_can_set_affinity(irq) || no_irq_affinity)
1da177e4
LT
100 return -EIO;
101
0de26520
RR
102 if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
103 return -ENOMEM;
104
4b060420
MT
105 if (type)
106 err = cpumask_parselist_user(buffer, count, new_value);
107 else
108 err = cpumask_parse_user(buffer, count, new_value);
1da177e4 109 if (err)
0de26520 110 goto free_cpumask;
1da177e4 111
6bdf197b 112 if (!is_affinity_mask_valid(new_value)) {
0de26520
RR
113 err = -EINVAL;
114 goto free_cpumask;
115 }
25d61578 116
1da177e4
LT
117 /*
118 * Do not allow disabling IRQs completely - it's a too easy
119 * way to make the system unusable accidentally :-) At least
120 * one online CPU still has to be targeted.
121 */
0de26520 122 if (!cpumask_intersects(new_value, cpu_online_mask)) {
eee45269
IK
123 /* Special case for empty set - allow the architecture
124 code to set default SMP affinity. */
3b8249e7 125 err = irq_select_affinity_usr(irq, new_value) ? -EINVAL : count;
0de26520
RR
126 } else {
127 irq_set_affinity(irq, new_value);
128 err = count;
129 }
130
131free_cpumask:
132 free_cpumask_var(new_value);
133 return err;
1da177e4
LT
134}
135
4b060420
MT
136static ssize_t irq_affinity_proc_write(struct file *file,
137 const char __user *buffer, size_t count, loff_t *pos)
138{
139 return write_irq_affinity(0, file, buffer, count, pos);
140}
141
142static ssize_t irq_affinity_list_proc_write(struct file *file,
143 const char __user *buffer, size_t count, loff_t *pos)
144{
145 return write_irq_affinity(1, file, buffer, count, pos);
146}
147
f18e439d 148static int irq_affinity_proc_open(struct inode *inode, struct file *file)
18404756 149{
d9dda78b 150 return single_open(file, irq_affinity_proc_show, PDE_DATA(inode));
18404756
MK
151}
152
4b060420
MT
153static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
154{
d9dda78b 155 return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));
4b060420
MT
156}
157
e7a297b0
PWJ
158static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
159{
d9dda78b 160 return single_open(file, irq_affinity_hint_proc_show, PDE_DATA(inode));
e7a297b0
PWJ
161}
162
f18e439d
AD
163static const struct file_operations irq_affinity_proc_fops = {
164 .open = irq_affinity_proc_open,
165 .read = seq_read,
166 .llseek = seq_lseek,
167 .release = single_release,
168 .write = irq_affinity_proc_write,
169};
170
e7a297b0
PWJ
171static const struct file_operations irq_affinity_hint_proc_fops = {
172 .open = irq_affinity_hint_proc_open,
173 .read = seq_read,
174 .llseek = seq_lseek,
175 .release = single_release,
176};
177
4b060420
MT
178static const struct file_operations irq_affinity_list_proc_fops = {
179 .open = irq_affinity_list_proc_open,
180 .read = seq_read,
181 .llseek = seq_lseek,
182 .release = single_release,
183 .write = irq_affinity_list_proc_write,
184};
185
f18e439d
AD
186static int default_affinity_show(struct seq_file *m, void *v)
187{
c1d7f03f 188 seq_printf(m, "%*pb\n", cpumask_pr_args(irq_default_affinity));
f18e439d
AD
189 return 0;
190}
191
192static ssize_t default_affinity_write(struct file *file,
193 const char __user *buffer, size_t count, loff_t *ppos)
18404756 194{
d036e67b 195 cpumask_var_t new_value;
f18e439d 196 int err;
18404756 197
d036e67b
RR
198 if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
199 return -ENOMEM;
200
201 err = cpumask_parse_user(buffer, count, new_value);
18404756 202 if (err)
d036e67b 203 goto out;
18404756 204
d036e67b
RR
205 if (!is_affinity_mask_valid(new_value)) {
206 err = -EINVAL;
207 goto out;
208 }
18404756
MK
209
210 /*
211 * Do not allow disabling IRQs completely - it's a too easy
212 * way to make the system unusable accidentally :-) At least
213 * one online CPU still has to be targeted.
214 */
d036e67b
RR
215 if (!cpumask_intersects(new_value, cpu_online_mask)) {
216 err = -EINVAL;
217 goto out;
218 }
18404756 219
d036e67b
RR
220 cpumask_copy(irq_default_affinity, new_value);
221 err = count;
18404756 222
d036e67b
RR
223out:
224 free_cpumask_var(new_value);
225 return err;
18404756 226}
f18e439d
AD
227
228static int default_affinity_open(struct inode *inode, struct file *file)
229{
d9dda78b 230 return single_open(file, default_affinity_show, PDE_DATA(inode));
f18e439d
AD
231}
232
233static const struct file_operations default_affinity_proc_fops = {
234 .open = default_affinity_open,
235 .read = seq_read,
236 .llseek = seq_lseek,
237 .release = single_release,
238 .write = default_affinity_write,
239};
92d6b71a
DS
240
241static int irq_node_proc_show(struct seq_file *m, void *v)
242{
243 struct irq_desc *desc = irq_to_desc((long) m->private);
244
6783011b 245 seq_printf(m, "%d\n", irq_desc_get_node(desc));
92d6b71a
DS
246 return 0;
247}
248
249static int irq_node_proc_open(struct inode *inode, struct file *file)
250{
d9dda78b 251 return single_open(file, irq_node_proc_show, PDE_DATA(inode));
92d6b71a
DS
252}
253
254static const struct file_operations irq_node_proc_fops = {
255 .open = irq_node_proc_open,
256 .read = seq_read,
257 .llseek = seq_lseek,
258 .release = single_release,
259};
1da177e4
LT
260#endif
261
a1afb637 262static int irq_spurious_proc_show(struct seq_file *m, void *v)
96d97cf0 263{
a1afb637
AD
264 struct irq_desc *desc = irq_to_desc((long) m->private);
265
266 seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
267 desc->irq_count, desc->irqs_unhandled,
268 jiffies_to_msecs(desc->last_unhandled));
269 return 0;
270}
271
272static int irq_spurious_proc_open(struct inode *inode, struct file *file)
273{
d9dda78b 274 return single_open(file, irq_spurious_proc_show, PDE_DATA(inode));
96d97cf0
AK
275}
276
a1afb637
AD
277static const struct file_operations irq_spurious_proc_fops = {
278 .open = irq_spurious_proc_open,
279 .read = seq_read,
280 .llseek = seq_lseek,
281 .release = single_release,
282};
283
1da177e4
LT
284#define MAX_NAMELEN 128
285
286static int name_unique(unsigned int irq, struct irqaction *new_action)
287{
08678b08 288 struct irq_desc *desc = irq_to_desc(irq);
1da177e4 289 struct irqaction *action;
d2d9433a
DA
290 unsigned long flags;
291 int ret = 1;
1da177e4 292
239007b8 293 raw_spin_lock_irqsave(&desc->lock, flags);
f944b5a7 294 for_each_action_of_desc(desc, action) {
1da177e4 295 if ((action != new_action) && action->name &&
d2d9433a
DA
296 !strcmp(new_action->name, action->name)) {
297 ret = 0;
298 break;
299 }
300 }
239007b8 301 raw_spin_unlock_irqrestore(&desc->lock, flags);
d2d9433a 302 return ret;
1da177e4
LT
303}
304
305void register_handler_proc(unsigned int irq, struct irqaction *action)
306{
307 char name [MAX_NAMELEN];
08678b08 308 struct irq_desc *desc = irq_to_desc(irq);
1da177e4 309
08678b08 310 if (!desc->dir || action->dir || !action->name ||
1da177e4
LT
311 !name_unique(irq, action))
312 return;
313
314 memset(name, 0, MAX_NAMELEN);
315 snprintf(name, MAX_NAMELEN, "%s", action->name);
316
317 /* create /proc/irq/1234/handler/ */
08678b08 318 action->dir = proc_mkdir(name, desc->dir);
1da177e4
LT
319}
320
321#undef MAX_NAMELEN
322
323#define MAX_NAMELEN 10
324
2c6927a3 325void register_irq_proc(unsigned int irq, struct irq_desc *desc)
1da177e4 326{
95c2b175 327 static DEFINE_MUTEX(register_lock);
1da177e4
LT
328 char name [MAX_NAMELEN];
329
95c2b175 330 if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip))
1da177e4
LT
331 return;
332
95c2b175
BH
333 /*
334 * irq directories are registered only when a handler is
335 * added, not when the descriptor is created, so multiple
336 * tasks might try to register at the same time.
337 */
338 mutex_lock(&register_lock);
339
340 if (desc->dir)
341 goto out_unlock;
342
1da177e4
LT
343 memset(name, 0, MAX_NAMELEN);
344 sprintf(name, "%d", irq);
345
346 /* create /proc/irq/1234 */
08678b08 347 desc->dir = proc_mkdir(name, root_irq_dir);
c82a43d4 348 if (!desc->dir)
95c2b175 349 goto out_unlock;
1da177e4
LT
350
351#ifdef CONFIG_SMP
f18e439d 352 /* create /proc/irq/<irq>/smp_affinity */
bab5c790 353 proc_create_data("smp_affinity", 0644, desc->dir,
f18e439d 354 &irq_affinity_proc_fops, (void *)(long)irq);
92d6b71a 355
e7a297b0 356 /* create /proc/irq/<irq>/affinity_hint */
bab5c790 357 proc_create_data("affinity_hint", 0444, desc->dir,
e7a297b0
PWJ
358 &irq_affinity_hint_proc_fops, (void *)(long)irq);
359
4b060420 360 /* create /proc/irq/<irq>/smp_affinity_list */
bab5c790 361 proc_create_data("smp_affinity_list", 0644, desc->dir,
4b060420
MT
362 &irq_affinity_list_proc_fops, (void *)(long)irq);
363
92d6b71a
DS
364 proc_create_data("node", 0444, desc->dir,
365 &irq_node_proc_fops, (void *)(long)irq);
1da177e4 366#endif
96d97cf0 367
a1afb637
AD
368 proc_create_data("spurious", 0444, desc->dir,
369 &irq_spurious_proc_fops, (void *)(long)irq);
95c2b175
BH
370
371out_unlock:
372 mutex_unlock(&register_lock);
1da177e4
LT
373}
374
13bfe99e
TG
375void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
376{
377 char name [MAX_NAMELEN];
378
379 if (!root_irq_dir || !desc->dir)
380 return;
381#ifdef CONFIG_SMP
382 remove_proc_entry("smp_affinity", desc->dir);
383 remove_proc_entry("affinity_hint", desc->dir);
def945ee 384 remove_proc_entry("smp_affinity_list", desc->dir);
13bfe99e
TG
385 remove_proc_entry("node", desc->dir);
386#endif
387 remove_proc_entry("spurious", desc->dir);
388
389 memset(name, 0, MAX_NAMELEN);
390 sprintf(name, "%u", irq);
391 remove_proc_entry(name, root_irq_dir);
392}
393
1da177e4
LT
394#undef MAX_NAMELEN
395
396void unregister_handler_proc(unsigned int irq, struct irqaction *action)
397{
a8ca16ea 398 proc_remove(action->dir);
1da177e4
LT
399}
400
3786fc71 401static void register_default_affinity_proc(void)
18404756
MK
402{
403#ifdef CONFIG_SMP
bab5c790 404 proc_create("irq/default_smp_affinity", 0644, NULL,
f18e439d 405 &default_affinity_proc_fops);
18404756
MK
406#endif
407}
408
1da177e4
LT
409void init_irq_proc(void)
410{
2c6927a3
YL
411 unsigned int irq;
412 struct irq_desc *desc;
1da177e4
LT
413
414 /* create /proc/irq */
415 root_irq_dir = proc_mkdir("irq", NULL);
416 if (!root_irq_dir)
417 return;
418
18404756
MK
419 register_default_affinity_proc();
420
1da177e4
LT
421 /*
422 * Create entries for all existing IRQs.
423 */
0b8f1efa
YL
424 for_each_irq_desc(irq, desc) {
425 if (!desc)
426 continue;
427
2c6927a3 428 register_irq_proc(irq, desc);
0b8f1efa 429 }
1da177e4
LT
430}
431
c78b9b65
TG
432#ifdef CONFIG_GENERIC_IRQ_SHOW
433
434int __weak arch_show_interrupts(struct seq_file *p, int prec)
435{
436 return 0;
437}
438
a6e120ed
TG
439#ifndef ACTUAL_NR_IRQS
440# define ACTUAL_NR_IRQS nr_irqs
441#endif
442
c78b9b65
TG
443int show_interrupts(struct seq_file *p, void *v)
444{
445 static int prec;
446
447 unsigned long flags, any_count = 0;
448 int i = *(loff_t *) v, j;
449 struct irqaction *action;
450 struct irq_desc *desc;
451
a6e120ed 452 if (i > ACTUAL_NR_IRQS)
c78b9b65
TG
453 return 0;
454
a6e120ed 455 if (i == ACTUAL_NR_IRQS)
c78b9b65
TG
456 return arch_show_interrupts(p, prec);
457
458 /* print header and calculate the width of the first column */
459 if (i == 0) {
460 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
461 j *= 10;
462
463 seq_printf(p, "%*s", prec + 8, "");
464 for_each_online_cpu(j)
465 seq_printf(p, "CPU%-8d", j);
466 seq_putc(p, '\n');
467 }
468
c291ee62 469 irq_lock_sparse();
c78b9b65
TG
470 desc = irq_to_desc(i);
471 if (!desc)
c291ee62 472 goto outsparse;
c78b9b65
TG
473
474 raw_spin_lock_irqsave(&desc->lock, flags);
475 for_each_online_cpu(j)
476 any_count |= kstat_irqs_cpu(i, j);
477 action = desc->action;
4717f133 478 if ((!action || irq_desc_is_chained(desc)) && !any_count)
c78b9b65
TG
479 goto out;
480
481 seq_printf(p, "%*d: ", prec, i);
482 for_each_online_cpu(j)
483 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
ab7798ff
TG
484
485 if (desc->irq_data.chip) {
486 if (desc->irq_data.chip->irq_print_chip)
487 desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
488 else if (desc->irq_data.chip->name)
489 seq_printf(p, " %8s", desc->irq_data.chip->name);
490 else
491 seq_printf(p, " %8s", "-");
492 } else {
493 seq_printf(p, " %8s", "None");
494 }
c12d2f42
GL
495 if (desc->irq_data.domain)
496 seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
94b2c363 497#ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
ab7798ff
TG
498 seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
499#endif
ee0401ec
TG
500 if (desc->name)
501 seq_printf(p, "-%-8s", desc->name);
c78b9b65
TG
502
503 if (action) {
504 seq_printf(p, " %s", action->name);
505 while ((action = action->next) != NULL)
506 seq_printf(p, ", %s", action->name);
507 }
508
509 seq_putc(p, '\n');
510out:
511 raw_spin_unlock_irqrestore(&desc->lock, flags);
c291ee62
TG
512outsparse:
513 irq_unlock_sparse();
c78b9b65
TG
514 return 0;
515}
516#endif