1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
5 * This file contains the /proc/irq/ handling code.
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>
16 #include "internals.h"
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.
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.
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.
35 static struct proc_dir_entry *root_irq_dir;
46 static int show_irq_affinity(int type, struct seq_file *m)
48 struct irq_desc *desc = irq_to_desc((long)m->private);
49 const struct cpumask *mask;
54 mask = desc->irq_common_data.affinity;
55 #ifdef CONFIG_GENERIC_PENDING_IRQ
56 if (irqd_is_setaffinity_pending(&desc->irq_data))
57 mask = desc->pending_mask;
62 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
63 mask = irq_data_get_effective_affinity_mask(&desc->irq_data);
73 seq_printf(m, "%*pbl\n", cpumask_pr_args(mask));
77 seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
83 static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
85 struct irq_desc *desc = irq_to_desc((long)m->private);
89 if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
92 raw_spin_lock_irqsave(&desc->lock, flags);
93 if (desc->affinity_hint)
94 cpumask_copy(mask, desc->affinity_hint);
95 raw_spin_unlock_irqrestore(&desc->lock, flags);
97 seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
98 free_cpumask_var(mask);
104 static int irq_affinity_proc_show(struct seq_file *m, void *v)
106 return show_irq_affinity(AFFINITY, m);
109 static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
111 return show_irq_affinity(AFFINITY_LIST, m);
115 static ssize_t write_irq_affinity(int type, struct file *file,
116 const char __user *buffer, size_t count, loff_t *pos)
118 unsigned int irq = (int)(long)PDE_DATA(file_inode(file));
119 cpumask_var_t new_value;
122 if (!irq_can_set_affinity_usr(irq) || no_irq_affinity)
125 if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
129 err = cpumask_parselist_user(buffer, count, new_value);
131 err = cpumask_parse_user(buffer, count, new_value);
136 * Do not allow disabling IRQs completely - it's a too easy
137 * way to make the system unusable accidentally :-) At least
138 * one online CPU still has to be targeted.
140 if (!cpumask_intersects(new_value, cpu_online_mask)) {
142 * Special case for empty set - allow the architecture code
143 * to set default SMP affinity.
145 err = irq_select_affinity_usr(irq) ? -EINVAL : count;
147 err = irq_set_affinity(irq, new_value);
153 free_cpumask_var(new_value);
157 static ssize_t irq_affinity_proc_write(struct file *file,
158 const char __user *buffer, size_t count, loff_t *pos)
160 return write_irq_affinity(0, file, buffer, count, pos);
163 static ssize_t irq_affinity_list_proc_write(struct file *file,
164 const char __user *buffer, size_t count, loff_t *pos)
166 return write_irq_affinity(1, file, buffer, count, pos);
169 static int irq_affinity_proc_open(struct inode *inode, struct file *file)
171 return single_open(file, irq_affinity_proc_show, PDE_DATA(inode));
174 static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
176 return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));
179 static const struct file_operations irq_affinity_proc_fops = {
180 .open = irq_affinity_proc_open,
183 .release = single_release,
184 .write = irq_affinity_proc_write,
187 static const struct file_operations irq_affinity_list_proc_fops = {
188 .open = irq_affinity_list_proc_open,
191 .release = single_release,
192 .write = irq_affinity_list_proc_write,
195 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
196 static int irq_effective_aff_proc_show(struct seq_file *m, void *v)
198 return show_irq_affinity(EFFECTIVE, m);
201 static int irq_effective_aff_list_proc_show(struct seq_file *m, void *v)
203 return show_irq_affinity(EFFECTIVE_LIST, m);
207 static int default_affinity_show(struct seq_file *m, void *v)
209 seq_printf(m, "%*pb\n", cpumask_pr_args(irq_default_affinity));
213 static ssize_t default_affinity_write(struct file *file,
214 const char __user *buffer, size_t count, loff_t *ppos)
216 cpumask_var_t new_value;
219 if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
222 err = cpumask_parse_user(buffer, count, new_value);
227 * Do not allow disabling IRQs completely - it's a too easy
228 * way to make the system unusable accidentally :-) At least
229 * one online CPU still has to be targeted.
231 if (!cpumask_intersects(new_value, cpu_online_mask)) {
236 cpumask_copy(irq_default_affinity, new_value);
240 free_cpumask_var(new_value);
244 static int default_affinity_open(struct inode *inode, struct file *file)
246 return single_open(file, default_affinity_show, PDE_DATA(inode));
249 static const struct file_operations default_affinity_proc_fops = {
250 .open = default_affinity_open,
253 .release = single_release,
254 .write = default_affinity_write,
257 static int irq_node_proc_show(struct seq_file *m, void *v)
259 struct irq_desc *desc = irq_to_desc((long) m->private);
261 seq_printf(m, "%d\n", irq_desc_get_node(desc));
266 static int irq_spurious_proc_show(struct seq_file *m, void *v)
268 struct irq_desc *desc = irq_to_desc((long) m->private);
270 seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
271 desc->irq_count, desc->irqs_unhandled,
272 jiffies_to_msecs(desc->last_unhandled));
276 #define MAX_NAMELEN 128
278 static int name_unique(unsigned int irq, struct irqaction *new_action)
280 struct irq_desc *desc = irq_to_desc(irq);
281 struct irqaction *action;
285 raw_spin_lock_irqsave(&desc->lock, flags);
286 for_each_action_of_desc(desc, action) {
287 if ((action != new_action) && action->name &&
288 !strcmp(new_action->name, action->name)) {
293 raw_spin_unlock_irqrestore(&desc->lock, flags);
297 void register_handler_proc(unsigned int irq, struct irqaction *action)
299 char name [MAX_NAMELEN];
300 struct irq_desc *desc = irq_to_desc(irq);
302 if (!desc->dir || action->dir || !action->name ||
303 !name_unique(irq, action))
306 snprintf(name, MAX_NAMELEN, "%s", action->name);
308 /* create /proc/irq/1234/handler/ */
309 action->dir = proc_mkdir(name, desc->dir);
314 #define MAX_NAMELEN 10
316 void register_irq_proc(unsigned int irq, struct irq_desc *desc)
318 static DEFINE_MUTEX(register_lock);
319 void __maybe_unused *irqp = (void *)(unsigned long) irq;
320 char name [MAX_NAMELEN];
322 if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip))
326 * irq directories are registered only when a handler is
327 * added, not when the descriptor is created, so multiple
328 * tasks might try to register at the same time.
330 mutex_lock(®ister_lock);
335 sprintf(name, "%d", irq);
337 /* create /proc/irq/1234 */
338 desc->dir = proc_mkdir(name, root_irq_dir);
343 /* create /proc/irq/<irq>/smp_affinity */
344 proc_create_data("smp_affinity", 0644, desc->dir,
345 &irq_affinity_proc_fops, irqp);
347 /* create /proc/irq/<irq>/affinity_hint */
348 proc_create_single_data("affinity_hint", 0444, desc->dir,
349 irq_affinity_hint_proc_show, irqp);
351 /* create /proc/irq/<irq>/smp_affinity_list */
352 proc_create_data("smp_affinity_list", 0644, desc->dir,
353 &irq_affinity_list_proc_fops, irqp);
355 proc_create_single_data("node", 0444, desc->dir, irq_node_proc_show,
357 # ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
358 proc_create_single_data("effective_affinity", 0444, desc->dir,
359 irq_effective_aff_proc_show, irqp);
360 proc_create_single_data("effective_affinity_list", 0444, desc->dir,
361 irq_effective_aff_list_proc_show, irqp);
364 proc_create_single_data("spurious", 0444, desc->dir,
365 irq_spurious_proc_show, (void *)(long)irq);
368 mutex_unlock(®ister_lock);
371 void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
373 char name [MAX_NAMELEN];
375 if (!root_irq_dir || !desc->dir)
378 remove_proc_entry("smp_affinity", desc->dir);
379 remove_proc_entry("affinity_hint", desc->dir);
380 remove_proc_entry("smp_affinity_list", desc->dir);
381 remove_proc_entry("node", desc->dir);
382 # ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
383 remove_proc_entry("effective_affinity", desc->dir);
384 remove_proc_entry("effective_affinity_list", desc->dir);
387 remove_proc_entry("spurious", desc->dir);
389 sprintf(name, "%u", irq);
390 remove_proc_entry(name, root_irq_dir);
395 void unregister_handler_proc(unsigned int irq, struct irqaction *action)
397 proc_remove(action->dir);
400 static void register_default_affinity_proc(void)
403 proc_create("irq/default_smp_affinity", 0644, NULL,
404 &default_affinity_proc_fops);
408 void init_irq_proc(void)
411 struct irq_desc *desc;
413 /* create /proc/irq */
414 root_irq_dir = proc_mkdir("irq", NULL);
418 register_default_affinity_proc();
421 * Create entries for all existing IRQs.
423 for_each_irq_desc(irq, desc)
424 register_irq_proc(irq, desc);
427 #ifdef CONFIG_GENERIC_IRQ_SHOW
429 int __weak arch_show_interrupts(struct seq_file *p, int prec)
434 #ifndef ACTUAL_NR_IRQS
435 # define ACTUAL_NR_IRQS nr_irqs
438 int show_interrupts(struct seq_file *p, void *v)
442 unsigned long flags, any_count = 0;
443 int i = *(loff_t *) v, j;
444 struct irqaction *action;
445 struct irq_desc *desc;
447 if (i > ACTUAL_NR_IRQS)
450 if (i == ACTUAL_NR_IRQS)
451 return arch_show_interrupts(p, prec);
453 /* print header and calculate the width of the first column */
455 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
458 seq_printf(p, "%*s", prec + 8, "");
459 for_each_online_cpu(j)
460 seq_printf(p, "CPU%-8d", j);
465 desc = irq_to_desc(i);
469 if (desc->kstat_irqs)
470 for_each_online_cpu(j)
471 any_count |= *per_cpu_ptr(desc->kstat_irqs, j);
473 if ((!desc->action || irq_desc_is_chained(desc)) && !any_count)
476 seq_printf(p, "%*d: ", prec, i);
477 for_each_online_cpu(j)
478 seq_printf(p, "%10u ", desc->kstat_irqs ?
479 *per_cpu_ptr(desc->kstat_irqs, j) : 0);
481 raw_spin_lock_irqsave(&desc->lock, flags);
482 if (desc->irq_data.chip) {
483 if (desc->irq_data.chip->irq_print_chip)
484 desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
485 else if (desc->irq_data.chip->name)
486 seq_printf(p, " %8s", desc->irq_data.chip->name);
488 seq_printf(p, " %8s", "-");
490 seq_printf(p, " %8s", "None");
492 if (desc->irq_data.domain)
493 seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
495 seq_printf(p, " %*s", prec, "");
496 #ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
497 seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
500 seq_printf(p, "-%-8s", desc->name);
502 action = desc->action;
504 seq_printf(p, " %s", action->name);
505 while ((action = action->next) != NULL)
506 seq_printf(p, ", %s", action->name);
510 raw_spin_unlock_irqrestore(&desc->lock, flags);