1 // SPDX-License-Identifier: GPL-2.0
3 * linux/kernel/irq/proc.c
5 * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
7 * This file contains the /proc/irq/ handling code.
10 #include <linux/irq.h>
11 #include <linux/gfp.h>
12 #include <linux/proc_fs.h>
13 #include <linux/seq_file.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/mutex.h>
18 #include "internals.h"
23 * procfs protects read/write of /proc/irq/N/ files against a
24 * concurrent free of the interrupt descriptor. remove_proc_entry()
25 * immediately prevents new read/writes to happen and waits for
26 * already running read/write functions to complete.
28 * We remove the proc entries first and then delete the interrupt
29 * descriptor from the radix tree and free it. So it is guaranteed
30 * that irq_to_desc(N) is valid as long as the read/writes are
31 * permitted by procfs.
33 * The read from /proc/interrupts is a different problem because there
34 * is no protection. So the lookup and the access to irqdesc
35 * information must be protected by sparse_irq_lock.
37 static struct proc_dir_entry *root_irq_dir;
48 static int show_irq_affinity(int type, struct seq_file *m)
50 struct irq_desc *desc = irq_to_desc((long)m->private);
51 const struct cpumask *mask;
56 mask = desc->irq_common_data.affinity;
57 #ifdef CONFIG_GENERIC_PENDING_IRQ
58 if (irqd_is_setaffinity_pending(&desc->irq_data))
59 mask = desc->pending_mask;
64 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
65 mask = irq_data_get_effective_affinity_mask(&desc->irq_data);
75 seq_printf(m, "%*pbl\n", cpumask_pr_args(mask));
79 seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
85 static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
87 struct irq_desc *desc = irq_to_desc((long)m->private);
91 if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
94 raw_spin_lock_irqsave(&desc->lock, flags);
95 if (desc->affinity_hint)
96 cpumask_copy(mask, desc->affinity_hint);
97 raw_spin_unlock_irqrestore(&desc->lock, flags);
99 seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
100 free_cpumask_var(mask);
105 #ifndef is_affinity_mask_valid
106 #define is_affinity_mask_valid(val) 1
110 static int irq_affinity_proc_show(struct seq_file *m, void *v)
112 return show_irq_affinity(AFFINITY, m);
115 static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
117 return show_irq_affinity(AFFINITY_LIST, m);
121 static ssize_t write_irq_affinity(int type, struct file *file,
122 const char __user *buffer, size_t count, loff_t *pos)
124 unsigned int irq = (int)(long)PDE_DATA(file_inode(file));
125 cpumask_var_t new_value;
128 if (!irq_can_set_affinity_usr(irq) || no_irq_affinity)
131 if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
135 err = cpumask_parselist_user(buffer, count, new_value);
137 err = cpumask_parse_user(buffer, count, new_value);
141 if (!is_affinity_mask_valid(new_value)) {
147 * Do not allow disabling IRQs completely - it's a too easy
148 * way to make the system unusable accidentally :-) At least
149 * one online CPU still has to be targeted.
151 if (!cpumask_intersects(new_value, cpu_online_mask)) {
153 * Special case for empty set - allow the architecture code
154 * to set default SMP affinity.
156 err = irq_select_affinity_usr(irq) ? -EINVAL : count;
158 irq_set_affinity(irq, new_value);
163 free_cpumask_var(new_value);
167 static ssize_t irq_affinity_proc_write(struct file *file,
168 const char __user *buffer, size_t count, loff_t *pos)
170 return write_irq_affinity(0, file, buffer, count, pos);
173 static ssize_t irq_affinity_list_proc_write(struct file *file,
174 const char __user *buffer, size_t count, loff_t *pos)
176 return write_irq_affinity(1, file, buffer, count, pos);
179 static int irq_affinity_proc_open(struct inode *inode, struct file *file)
181 return single_open(file, irq_affinity_proc_show, PDE_DATA(inode));
184 static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
186 return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));
189 static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
191 return single_open(file, irq_affinity_hint_proc_show, PDE_DATA(inode));
194 static const struct file_operations irq_affinity_proc_fops = {
195 .open = irq_affinity_proc_open,
198 .release = single_release,
199 .write = irq_affinity_proc_write,
202 static const struct file_operations irq_affinity_hint_proc_fops = {
203 .open = irq_affinity_hint_proc_open,
206 .release = single_release,
209 static const struct file_operations irq_affinity_list_proc_fops = {
210 .open = irq_affinity_list_proc_open,
213 .release = single_release,
214 .write = irq_affinity_list_proc_write,
217 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
218 static int irq_effective_aff_proc_show(struct seq_file *m, void *v)
220 return show_irq_affinity(EFFECTIVE, m);
223 static int irq_effective_aff_list_proc_show(struct seq_file *m, void *v)
225 return show_irq_affinity(EFFECTIVE_LIST, m);
228 static int irq_effective_aff_proc_open(struct inode *inode, struct file *file)
230 return single_open(file, irq_effective_aff_proc_show, PDE_DATA(inode));
233 static int irq_effective_aff_list_proc_open(struct inode *inode,
236 return single_open(file, irq_effective_aff_list_proc_show,
240 static const struct file_operations irq_effective_aff_proc_fops = {
241 .open = irq_effective_aff_proc_open,
244 .release = single_release,
247 static const struct file_operations irq_effective_aff_list_proc_fops = {
248 .open = irq_effective_aff_list_proc_open,
251 .release = single_release,
255 static int default_affinity_show(struct seq_file *m, void *v)
257 seq_printf(m, "%*pb\n", cpumask_pr_args(irq_default_affinity));
261 static ssize_t default_affinity_write(struct file *file,
262 const char __user *buffer, size_t count, loff_t *ppos)
264 cpumask_var_t new_value;
267 if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
270 err = cpumask_parse_user(buffer, count, new_value);
274 if (!is_affinity_mask_valid(new_value)) {
280 * Do not allow disabling IRQs completely - it's a too easy
281 * way to make the system unusable accidentally :-) At least
282 * one online CPU still has to be targeted.
284 if (!cpumask_intersects(new_value, cpu_online_mask)) {
289 cpumask_copy(irq_default_affinity, new_value);
293 free_cpumask_var(new_value);
297 static int default_affinity_open(struct inode *inode, struct file *file)
299 return single_open(file, default_affinity_show, PDE_DATA(inode));
302 static const struct file_operations default_affinity_proc_fops = {
303 .open = default_affinity_open,
306 .release = single_release,
307 .write = default_affinity_write,
310 static int irq_node_proc_show(struct seq_file *m, void *v)
312 struct irq_desc *desc = irq_to_desc((long) m->private);
314 seq_printf(m, "%d\n", irq_desc_get_node(desc));
318 static int irq_node_proc_open(struct inode *inode, struct file *file)
320 return single_open(file, irq_node_proc_show, PDE_DATA(inode));
323 static const struct file_operations irq_node_proc_fops = {
324 .open = irq_node_proc_open,
327 .release = single_release,
331 static int irq_spurious_proc_show(struct seq_file *m, void *v)
333 struct irq_desc *desc = irq_to_desc((long) m->private);
335 seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
336 desc->irq_count, desc->irqs_unhandled,
337 jiffies_to_msecs(desc->last_unhandled));
341 static int irq_spurious_proc_open(struct inode *inode, struct file *file)
343 return single_open(file, irq_spurious_proc_show, PDE_DATA(inode));
346 static const struct file_operations irq_spurious_proc_fops = {
347 .open = irq_spurious_proc_open,
350 .release = single_release,
353 #define MAX_NAMELEN 128
355 static int name_unique(unsigned int irq, struct irqaction *new_action)
357 struct irq_desc *desc = irq_to_desc(irq);
358 struct irqaction *action;
362 raw_spin_lock_irqsave(&desc->lock, flags);
363 for_each_action_of_desc(desc, action) {
364 if ((action != new_action) && action->name &&
365 !strcmp(new_action->name, action->name)) {
370 raw_spin_unlock_irqrestore(&desc->lock, flags);
374 void register_handler_proc(unsigned int irq, struct irqaction *action)
376 char name [MAX_NAMELEN];
377 struct irq_desc *desc = irq_to_desc(irq);
379 if (!desc->dir || action->dir || !action->name ||
380 !name_unique(irq, action))
383 snprintf(name, MAX_NAMELEN, "%s", action->name);
385 /* create /proc/irq/1234/handler/ */
386 action->dir = proc_mkdir(name, desc->dir);
391 #define MAX_NAMELEN 10
393 void register_irq_proc(unsigned int irq, struct irq_desc *desc)
395 static DEFINE_MUTEX(register_lock);
396 void __maybe_unused *irqp = (void *)(unsigned long) irq;
397 char name [MAX_NAMELEN];
399 if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip))
403 * irq directories are registered only when a handler is
404 * added, not when the descriptor is created, so multiple
405 * tasks might try to register at the same time.
407 mutex_lock(®ister_lock);
412 sprintf(name, "%d", irq);
414 /* create /proc/irq/1234 */
415 desc->dir = proc_mkdir(name, root_irq_dir);
420 /* create /proc/irq/<irq>/smp_affinity */
421 proc_create_data("smp_affinity", 0644, desc->dir,
422 &irq_affinity_proc_fops, irqp);
424 /* create /proc/irq/<irq>/affinity_hint */
425 proc_create_data("affinity_hint", 0444, desc->dir,
426 &irq_affinity_hint_proc_fops, irqp);
428 /* create /proc/irq/<irq>/smp_affinity_list */
429 proc_create_data("smp_affinity_list", 0644, desc->dir,
430 &irq_affinity_list_proc_fops, irqp);
432 proc_create_data("node", 0444, desc->dir,
433 &irq_node_proc_fops, irqp);
434 # ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
435 proc_create_data("effective_affinity", 0444, desc->dir,
436 &irq_effective_aff_proc_fops, irqp);
437 proc_create_data("effective_affinity_list", 0444, desc->dir,
438 &irq_effective_aff_list_proc_fops, irqp);
441 proc_create_data("spurious", 0444, desc->dir,
442 &irq_spurious_proc_fops, (void *)(long)irq);
445 mutex_unlock(®ister_lock);
448 void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
450 char name [MAX_NAMELEN];
452 if (!root_irq_dir || !desc->dir)
455 remove_proc_entry("smp_affinity", desc->dir);
456 remove_proc_entry("affinity_hint", desc->dir);
457 remove_proc_entry("smp_affinity_list", desc->dir);
458 remove_proc_entry("node", desc->dir);
459 # ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
460 remove_proc_entry("effective_affinity", desc->dir);
461 remove_proc_entry("effective_affinity_list", desc->dir);
464 remove_proc_entry("spurious", desc->dir);
466 sprintf(name, "%u", irq);
467 remove_proc_entry(name, root_irq_dir);
472 void unregister_handler_proc(unsigned int irq, struct irqaction *action)
474 proc_remove(action->dir);
477 static void register_default_affinity_proc(void)
480 proc_create("irq/default_smp_affinity", 0644, NULL,
481 &default_affinity_proc_fops);
485 void init_irq_proc(void)
488 struct irq_desc *desc;
490 /* create /proc/irq */
491 root_irq_dir = proc_mkdir("irq", NULL);
495 register_default_affinity_proc();
498 * Create entries for all existing IRQs.
500 for_each_irq_desc(irq, desc)
501 register_irq_proc(irq, desc);
504 #ifdef CONFIG_GENERIC_IRQ_SHOW
506 int __weak arch_show_interrupts(struct seq_file *p, int prec)
511 #ifndef ACTUAL_NR_IRQS
512 # define ACTUAL_NR_IRQS nr_irqs
515 int show_interrupts(struct seq_file *p, void *v)
519 unsigned long flags, any_count = 0;
520 int i = *(loff_t *) v, j;
521 struct irqaction *action;
522 struct irq_desc *desc;
524 if (i > ACTUAL_NR_IRQS)
527 if (i == ACTUAL_NR_IRQS)
528 return arch_show_interrupts(p, prec);
530 /* print header and calculate the width of the first column */
532 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
535 seq_printf(p, "%*s", prec + 8, "");
536 for_each_online_cpu(j)
537 seq_printf(p, "CPU%-8d", j);
542 desc = irq_to_desc(i);
546 raw_spin_lock_irqsave(&desc->lock, flags);
547 for_each_online_cpu(j)
548 any_count |= kstat_irqs_cpu(i, j);
549 action = desc->action;
550 if ((!action || irq_desc_is_chained(desc)) && !any_count)
553 seq_printf(p, "%*d: ", prec, i);
554 for_each_online_cpu(j)
555 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
557 if (desc->irq_data.chip) {
558 if (desc->irq_data.chip->irq_print_chip)
559 desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
560 else if (desc->irq_data.chip->name)
561 seq_printf(p, " %8s", desc->irq_data.chip->name);
563 seq_printf(p, " %8s", "-");
565 seq_printf(p, " %8s", "None");
567 if (desc->irq_data.domain)
568 seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
570 seq_printf(p, " %*s", prec, "");
571 #ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
572 seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
575 seq_printf(p, "-%-8s", desc->name);
578 seq_printf(p, " %s", action->name);
579 while ((action = action->next) != NULL)
580 seq_printf(p, ", %s", action->name);
585 raw_spin_unlock_irqrestore(&desc->lock, flags);