Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
4 : *
5 : * This file contains the /proc/irq/ handling code.
6 : */
7 :
8 : #include <linux/irq.h>
9 : #include <linux/gfp.h>
10 : #include <linux/proc_fs.h>
11 : #include <linux/seq_file.h>
12 : #include <linux/interrupt.h>
13 : #include <linux/kernel_stat.h>
14 : #include <linux/mutex.h>
15 :
16 : #include "internals.h"
17 :
18 : /*
19 : * Access rules:
20 : *
21 : * procfs protects read/write of /proc/irq/N/ files against a
22 : * concurrent free of the interrupt descriptor. remove_proc_entry()
23 : * immediately prevents new read/writes to happen and waits for
24 : * already running read/write functions to complete.
25 : *
26 : * We remove the proc entries first and then delete the interrupt
27 : * descriptor from the radix tree and free it. So it is guaranteed
28 : * that irq_to_desc(N) is valid as long as the read/writes are
29 : * permitted by procfs.
30 : *
31 : * The read from /proc/interrupts is a different problem because there
32 : * is no protection. So the lookup and the access to irqdesc
33 : * information must be protected by sparse_irq_lock.
34 : */
35 : static struct proc_dir_entry *root_irq_dir;
36 :
37 : #ifdef CONFIG_SMP
38 :
39 : enum {
40 : AFFINITY,
41 : AFFINITY_LIST,
42 : EFFECTIVE,
43 : EFFECTIVE_LIST,
44 : };
45 :
46 0 : static int show_irq_affinity(int type, struct seq_file *m)
47 : {
48 0 : struct irq_desc *desc = irq_to_desc((long)m->private);
49 0 : const struct cpumask *mask;
50 :
51 0 : switch (type) {
52 0 : case AFFINITY:
53 : case AFFINITY_LIST:
54 0 : mask = desc->irq_common_data.affinity;
55 : #ifdef CONFIG_GENERIC_PENDING_IRQ
56 0 : if (irqd_is_setaffinity_pending(&desc->irq_data))
57 0 : mask = desc->pending_mask;
58 : #endif
59 : break;
60 0 : case EFFECTIVE:
61 : case EFFECTIVE_LIST:
62 : #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
63 0 : mask = irq_data_get_effective_affinity_mask(&desc->irq_data);
64 0 : break;
65 : #endif
66 : default:
67 : return -EINVAL;
68 : }
69 :
70 0 : switch (type) {
71 0 : case AFFINITY_LIST:
72 : case EFFECTIVE_LIST:
73 0 : seq_printf(m, "%*pbl\n", cpumask_pr_args(mask));
74 0 : break;
75 0 : case AFFINITY:
76 : case EFFECTIVE:
77 0 : seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
78 0 : break;
79 : }
80 : return 0;
81 : }
82 :
83 0 : static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
84 : {
85 0 : struct irq_desc *desc = irq_to_desc((long)m->private);
86 0 : unsigned long flags;
87 0 : cpumask_var_t mask;
88 :
89 0 : if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
90 : return -ENOMEM;
91 :
92 0 : raw_spin_lock_irqsave(&desc->lock, flags);
93 0 : if (desc->affinity_hint)
94 0 : cpumask_copy(mask, desc->affinity_hint);
95 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
96 :
97 0 : seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
98 0 : free_cpumask_var(mask);
99 :
100 0 : return 0;
101 : }
102 :
103 : int no_irq_affinity;
104 0 : static int irq_affinity_proc_show(struct seq_file *m, void *v)
105 : {
106 0 : return show_irq_affinity(AFFINITY, m);
107 : }
108 :
109 0 : static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
110 : {
111 0 : return show_irq_affinity(AFFINITY_LIST, m);
112 : }
113 :
114 : #ifndef CONFIG_AUTO_IRQ_AFFINITY
115 : static inline int irq_select_affinity_usr(unsigned int irq)
116 : {
117 : /*
118 : * If the interrupt is started up already then this fails. The
119 : * interrupt is assigned to an online CPU already. There is no
120 : * point to move it around randomly. Tell user space that the
121 : * selected mask is bogus.
122 : *
123 : * If not then any change to the affinity is pointless because the
124 : * startup code invokes irq_setup_affinity() which will select
125 : * a online CPU anyway.
126 : */
127 : return -EINVAL;
128 : }
129 : #else
130 : /* ALPHA magic affinity auto selector. Keep it for historical reasons. */
131 : static inline int irq_select_affinity_usr(unsigned int irq)
132 : {
133 : return irq_select_affinity(irq);
134 : }
135 : #endif
136 :
137 0 : static ssize_t write_irq_affinity(int type, struct file *file,
138 : const char __user *buffer, size_t count, loff_t *pos)
139 : {
140 0 : unsigned int irq = (int)(long)PDE_DATA(file_inode(file));
141 0 : cpumask_var_t new_value;
142 0 : int err;
143 :
144 0 : if (!irq_can_set_affinity_usr(irq) || no_irq_affinity)
145 : return -EIO;
146 :
147 0 : if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
148 : return -ENOMEM;
149 :
150 0 : if (type)
151 0 : err = cpumask_parselist_user(buffer, count, new_value);
152 : else
153 0 : err = cpumask_parse_user(buffer, count, new_value);
154 0 : if (err)
155 0 : goto free_cpumask;
156 :
157 : /*
158 : * Do not allow disabling IRQs completely - it's a too easy
159 : * way to make the system unusable accidentally :-) At least
160 : * one online CPU still has to be targeted.
161 : */
162 0 : if (!cpumask_intersects(new_value, cpu_online_mask)) {
163 : /*
164 : * Special case for empty set - allow the architecture code
165 : * to set default SMP affinity.
166 : */
167 0 : err = irq_select_affinity_usr(irq) ? -EINVAL : count;
168 : } else {
169 0 : err = irq_set_affinity(irq, new_value);
170 0 : if (!err)
171 0 : err = count;
172 : }
173 :
174 0 : free_cpumask:
175 0 : free_cpumask_var(new_value);
176 0 : return err;
177 : }
178 :
179 0 : static ssize_t irq_affinity_proc_write(struct file *file,
180 : const char __user *buffer, size_t count, loff_t *pos)
181 : {
182 0 : return write_irq_affinity(0, file, buffer, count, pos);
183 : }
184 :
185 0 : static ssize_t irq_affinity_list_proc_write(struct file *file,
186 : const char __user *buffer, size_t count, loff_t *pos)
187 : {
188 0 : return write_irq_affinity(1, file, buffer, count, pos);
189 : }
190 :
191 0 : static int irq_affinity_proc_open(struct inode *inode, struct file *file)
192 : {
193 0 : return single_open(file, irq_affinity_proc_show, PDE_DATA(inode));
194 : }
195 :
196 0 : static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
197 : {
198 0 : return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));
199 : }
200 :
201 : static const struct proc_ops irq_affinity_proc_ops = {
202 : .proc_open = irq_affinity_proc_open,
203 : .proc_read = seq_read,
204 : .proc_lseek = seq_lseek,
205 : .proc_release = single_release,
206 : .proc_write = irq_affinity_proc_write,
207 : };
208 :
209 : static const struct proc_ops irq_affinity_list_proc_ops = {
210 : .proc_open = irq_affinity_list_proc_open,
211 : .proc_read = seq_read,
212 : .proc_lseek = seq_lseek,
213 : .proc_release = single_release,
214 : .proc_write = irq_affinity_list_proc_write,
215 : };
216 :
217 : #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
218 0 : static int irq_effective_aff_proc_show(struct seq_file *m, void *v)
219 : {
220 0 : return show_irq_affinity(EFFECTIVE, m);
221 : }
222 :
223 0 : static int irq_effective_aff_list_proc_show(struct seq_file *m, void *v)
224 : {
225 0 : return show_irq_affinity(EFFECTIVE_LIST, m);
226 : }
227 : #endif
228 :
229 0 : static int default_affinity_show(struct seq_file *m, void *v)
230 : {
231 0 : seq_printf(m, "%*pb\n", cpumask_pr_args(irq_default_affinity));
232 0 : return 0;
233 : }
234 :
235 0 : static ssize_t default_affinity_write(struct file *file,
236 : const char __user *buffer, size_t count, loff_t *ppos)
237 : {
238 0 : cpumask_var_t new_value;
239 0 : int err;
240 :
241 0 : if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
242 : return -ENOMEM;
243 :
244 0 : err = cpumask_parse_user(buffer, count, new_value);
245 0 : if (err)
246 0 : goto out;
247 :
248 : /*
249 : * Do not allow disabling IRQs completely - it's a too easy
250 : * way to make the system unusable accidentally :-) At least
251 : * one online CPU still has to be targeted.
252 : */
253 0 : if (!cpumask_intersects(new_value, cpu_online_mask)) {
254 0 : err = -EINVAL;
255 0 : goto out;
256 : }
257 :
258 0 : cpumask_copy(irq_default_affinity, new_value);
259 0 : err = count;
260 :
261 0 : out:
262 0 : free_cpumask_var(new_value);
263 0 : return err;
264 : }
265 :
266 0 : static int default_affinity_open(struct inode *inode, struct file *file)
267 : {
268 0 : return single_open(file, default_affinity_show, PDE_DATA(inode));
269 : }
270 :
271 : static const struct proc_ops default_affinity_proc_ops = {
272 : .proc_open = default_affinity_open,
273 : .proc_read = seq_read,
274 : .proc_lseek = seq_lseek,
275 : .proc_release = single_release,
276 : .proc_write = default_affinity_write,
277 : };
278 :
279 0 : static int irq_node_proc_show(struct seq_file *m, void *v)
280 : {
281 0 : struct irq_desc *desc = irq_to_desc((long) m->private);
282 :
283 0 : seq_printf(m, "%d\n", irq_desc_get_node(desc));
284 0 : return 0;
285 : }
286 : #endif
287 :
288 0 : static int irq_spurious_proc_show(struct seq_file *m, void *v)
289 : {
290 0 : struct irq_desc *desc = irq_to_desc((long) m->private);
291 :
292 0 : seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
293 : desc->irq_count, desc->irqs_unhandled,
294 : jiffies_to_msecs(desc->last_unhandled));
295 0 : return 0;
296 : }
297 :
298 : #define MAX_NAMELEN 128
299 :
300 3 : static int name_unique(unsigned int irq, struct irqaction *new_action)
301 : {
302 3 : struct irq_desc *desc = irq_to_desc(irq);
303 3 : struct irqaction *action;
304 3 : unsigned long flags;
305 3 : int ret = 1;
306 :
307 3 : raw_spin_lock_irqsave(&desc->lock, flags);
308 6 : for_each_action_of_desc(desc, action) {
309 3 : if ((action != new_action) && action->name &&
310 0 : !strcmp(new_action->name, action->name)) {
311 : ret = 0;
312 : break;
313 : }
314 : }
315 3 : raw_spin_unlock_irqrestore(&desc->lock, flags);
316 3 : return ret;
317 : }
318 :
319 4 : void register_handler_proc(unsigned int irq, struct irqaction *action)
320 : {
321 4 : char name [MAX_NAMELEN];
322 4 : struct irq_desc *desc = irq_to_desc(irq);
323 :
324 7 : if (!desc->dir || action->dir || !action->name ||
325 3 : !name_unique(irq, action))
326 1 : return;
327 :
328 3 : snprintf(name, MAX_NAMELEN, "%s", action->name);
329 :
330 : /* create /proc/irq/1234/handler/ */
331 3 : action->dir = proc_mkdir(name, desc->dir);
332 : }
333 :
334 : #undef MAX_NAMELEN
335 :
336 : #define MAX_NAMELEN 10
337 :
338 20 : void register_irq_proc(unsigned int irq, struct irq_desc *desc)
339 : {
340 20 : static DEFINE_MUTEX(register_lock);
341 20 : void __maybe_unused *irqp = (void *)(unsigned long) irq;
342 20 : char name [MAX_NAMELEN];
343 :
344 20 : if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip))
345 1 : return;
346 :
347 : /*
348 : * irq directories are registered only when a handler is
349 : * added, not when the descriptor is created, so multiple
350 : * tasks might try to register at the same time.
351 : */
352 19 : mutex_lock(®ister_lock);
353 :
354 19 : if (desc->dir)
355 3 : goto out_unlock;
356 :
357 16 : sprintf(name, "%d", irq);
358 :
359 : /* create /proc/irq/1234 */
360 16 : desc->dir = proc_mkdir(name, root_irq_dir);
361 16 : if (!desc->dir)
362 0 : goto out_unlock;
363 :
364 : #ifdef CONFIG_SMP
365 : /* create /proc/irq/<irq>/smp_affinity */
366 16 : proc_create_data("smp_affinity", 0644, desc->dir,
367 : &irq_affinity_proc_ops, irqp);
368 :
369 : /* create /proc/irq/<irq>/affinity_hint */
370 16 : proc_create_single_data("affinity_hint", 0444, desc->dir,
371 : irq_affinity_hint_proc_show, irqp);
372 :
373 : /* create /proc/irq/<irq>/smp_affinity_list */
374 16 : proc_create_data("smp_affinity_list", 0644, desc->dir,
375 : &irq_affinity_list_proc_ops, irqp);
376 :
377 16 : proc_create_single_data("node", 0444, desc->dir, irq_node_proc_show,
378 : irqp);
379 : # ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
380 16 : proc_create_single_data("effective_affinity", 0444, desc->dir,
381 : irq_effective_aff_proc_show, irqp);
382 16 : proc_create_single_data("effective_affinity_list", 0444, desc->dir,
383 : irq_effective_aff_list_proc_show, irqp);
384 : # endif
385 : #endif
386 16 : proc_create_single_data("spurious", 0444, desc->dir,
387 16 : irq_spurious_proc_show, (void *)(long)irq);
388 :
389 19 : out_unlock:
390 19 : mutex_unlock(®ister_lock);
391 : }
392 :
393 0 : void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
394 : {
395 0 : char name [MAX_NAMELEN];
396 :
397 0 : if (!root_irq_dir || !desc->dir)
398 0 : return;
399 : #ifdef CONFIG_SMP
400 0 : remove_proc_entry("smp_affinity", desc->dir);
401 0 : remove_proc_entry("affinity_hint", desc->dir);
402 0 : remove_proc_entry("smp_affinity_list", desc->dir);
403 0 : remove_proc_entry("node", desc->dir);
404 : # ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
405 0 : remove_proc_entry("effective_affinity", desc->dir);
406 0 : remove_proc_entry("effective_affinity_list", desc->dir);
407 : # endif
408 : #endif
409 0 : remove_proc_entry("spurious", desc->dir);
410 :
411 0 : sprintf(name, "%u", irq);
412 0 : remove_proc_entry(name, root_irq_dir);
413 : }
414 :
415 : #undef MAX_NAMELEN
416 :
417 0 : void unregister_handler_proc(unsigned int irq, struct irqaction *action)
418 : {
419 0 : proc_remove(action->dir);
420 0 : }
421 :
422 1 : static void register_default_affinity_proc(void)
423 : {
424 : #ifdef CONFIG_SMP
425 1 : proc_create("irq/default_smp_affinity", 0644, NULL,
426 : &default_affinity_proc_ops);
427 : #endif
428 1 : }
429 :
430 1 : void init_irq_proc(void)
431 : {
432 1 : unsigned int irq;
433 1 : struct irq_desc *desc;
434 :
435 : /* create /proc/irq */
436 1 : root_irq_dir = proc_mkdir("irq", NULL);
437 1 : if (!root_irq_dir)
438 : return;
439 :
440 1 : register_default_affinity_proc();
441 :
442 : /*
443 : * Create entries for all existing IRQs.
444 : */
445 73 : for_each_irq_desc(irq, desc)
446 16 : register_irq_proc(irq, desc);
447 : }
448 :
449 : #ifdef CONFIG_GENERIC_IRQ_SHOW
450 :
451 0 : int __weak arch_show_interrupts(struct seq_file *p, int prec)
452 : {
453 0 : return 0;
454 : }
455 :
456 : #ifndef ACTUAL_NR_IRQS
457 : # define ACTUAL_NR_IRQS nr_irqs
458 : #endif
459 :
460 0 : int show_interrupts(struct seq_file *p, void *v)
461 : {
462 0 : static int prec;
463 :
464 0 : unsigned long flags, any_count = 0;
465 0 : int i = *(loff_t *) v, j;
466 0 : struct irqaction *action;
467 0 : struct irq_desc *desc;
468 :
469 0 : if (i > ACTUAL_NR_IRQS)
470 : return 0;
471 :
472 0 : if (i == ACTUAL_NR_IRQS)
473 0 : return arch_show_interrupts(p, prec);
474 :
475 : /* print header and calculate the width of the first column */
476 0 : if (i == 0) {
477 0 : for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
478 0 : j *= 10;
479 :
480 0 : seq_printf(p, "%*s", prec + 8, "");
481 0 : for_each_online_cpu(j)
482 0 : seq_printf(p, "CPU%-8d", j);
483 0 : seq_putc(p, '\n');
484 : }
485 :
486 0 : rcu_read_lock();
487 0 : desc = irq_to_desc(i);
488 0 : if (!desc || irq_settings_is_hidden(desc))
489 0 : goto outsparse;
490 :
491 0 : if (desc->kstat_irqs) {
492 0 : for_each_online_cpu(j)
493 0 : any_count |= data_race(*per_cpu_ptr(desc->kstat_irqs, j));
494 : }
495 :
496 0 : if ((!desc->action || irq_desc_is_chained(desc)) && !any_count)
497 0 : goto outsparse;
498 :
499 0 : seq_printf(p, "%*d: ", prec, i);
500 0 : for_each_online_cpu(j)
501 0 : seq_printf(p, "%10u ", desc->kstat_irqs ?
502 0 : *per_cpu_ptr(desc->kstat_irqs, j) : 0);
503 :
504 0 : raw_spin_lock_irqsave(&desc->lock, flags);
505 0 : if (desc->irq_data.chip) {
506 0 : if (desc->irq_data.chip->irq_print_chip)
507 0 : desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
508 0 : else if (desc->irq_data.chip->name)
509 0 : seq_printf(p, " %8s", desc->irq_data.chip->name);
510 : else
511 0 : seq_printf(p, " %8s", "-");
512 : } else {
513 0 : seq_printf(p, " %8s", "None");
514 : }
515 0 : if (desc->irq_data.domain)
516 0 : seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
517 : else
518 0 : seq_printf(p, " %*s", prec, "");
519 : #ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
520 : seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
521 : #endif
522 0 : if (desc->name)
523 0 : seq_printf(p, "-%-8s", desc->name);
524 :
525 0 : action = desc->action;
526 0 : if (action) {
527 0 : seq_printf(p, " %s", action->name);
528 0 : while ((action = action->next) != NULL)
529 0 : seq_printf(p, ", %s", action->name);
530 : }
531 :
532 0 : seq_putc(p, '\n');
533 0 : raw_spin_unlock_irqrestore(&desc->lock, flags);
534 0 : outsparse:
535 0 : rcu_read_unlock();
536 0 : return 0;
537 : }
538 : #endif
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