// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
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*
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* This file contains the /proc/irq/ handling code.
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*/
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#include <linux/irq.h>
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#include <linux/gfp.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include <linux/mutex.h>
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#include "internals.h"
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/*
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* Access rules:
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*
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* procfs protects read/write of /proc/irq/N/ files against a
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* concurrent free of the interrupt descriptor. remove_proc_entry()
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* immediately prevents new read/writes to happen and waits for
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* already running read/write functions to complete.
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*
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* We remove the proc entries first and then delete the interrupt
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* descriptor from the radix tree and free it. So it is guaranteed
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* that irq_to_desc(N) is valid as long as the read/writes are
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* permitted by procfs.
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*
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* The read from /proc/interrupts is a different problem because there
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* is no protection. So the lookup and the access to irqdesc
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* information must be protected by sparse_irq_lock.
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*/
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static struct proc_dir_entry *root_irq_dir;
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#ifdef CONFIG_SMP
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enum {
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AFFINITY,
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AFFINITY_LIST,
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EFFECTIVE,
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EFFECTIVE_LIST,
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};
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static int show_irq_affinity(int type, struct seq_file *m)
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{
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struct irq_desc *desc = irq_to_desc((long)m->private);
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const struct cpumask *mask;
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switch (type) {
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case AFFINITY:
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case AFFINITY_LIST:
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mask = desc->irq_common_data.affinity;
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#ifdef CONFIG_GENERIC_PENDING_IRQ
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if (irqd_is_setaffinity_pending(&desc->irq_data))
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mask = desc->pending_mask;
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#endif
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break;
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case EFFECTIVE:
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case EFFECTIVE_LIST:
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#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
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mask = irq_data_get_effective_affinity_mask(&desc->irq_data);
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break;
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#endif
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default:
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return -EINVAL;
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}
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switch (type) {
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case AFFINITY_LIST:
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case EFFECTIVE_LIST:
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seq_printf(m, "%*pbl\n", cpumask_pr_args(mask));
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break;
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case AFFINITY:
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case EFFECTIVE:
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seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
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break;
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}
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return 0;
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}
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static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
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{
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struct irq_desc *desc = irq_to_desc((long)m->private);
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unsigned long flags;
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cpumask_var_t mask;
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if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
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return -ENOMEM;
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raw_spin_lock_irqsave(&desc->lock, flags);
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if (desc->affinity_hint)
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cpumask_copy(mask, desc->affinity_hint);
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raw_spin_unlock_irqrestore(&desc->lock, flags);
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seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
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free_cpumask_var(mask);
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return 0;
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}
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int no_irq_affinity;
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static int irq_affinity_proc_show(struct seq_file *m, void *v)
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{
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return show_irq_affinity(AFFINITY, m);
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}
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static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
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{
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return show_irq_affinity(AFFINITY_LIST, m);
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}
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#ifndef CONFIG_AUTO_IRQ_AFFINITY
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static inline int irq_select_affinity_usr(unsigned int irq)
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{
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/*
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* If the interrupt is started up already then this fails. The
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* interrupt is assigned to an online CPU already. There is no
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* point to move it around randomly. Tell user space that the
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* selected mask is bogus.
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*
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* If not then any change to the affinity is pointless because the
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* startup code invokes irq_setup_affinity() which will select
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* a online CPU anyway.
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*/
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return -EINVAL;
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}
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#else
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/* ALPHA magic affinity auto selector. Keep it for historical reasons. */
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static inline int irq_select_affinity_usr(unsigned int irq)
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{
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return irq_select_affinity(irq);
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}
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#endif
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static ssize_t write_irq_affinity(int type, struct file *file,
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const char __user *buffer, size_t count, loff_t *pos)
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{
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unsigned int irq = (int)(long)PDE_DATA(file_inode(file));
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cpumask_var_t new_value;
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int err;
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if (!irq_can_set_affinity_usr(irq) || no_irq_affinity)
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return -EIO;
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if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
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return -ENOMEM;
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if (type)
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err = cpumask_parselist_user(buffer, count, new_value);
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else
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err = cpumask_parse_user(buffer, count, new_value);
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if (err)
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goto free_cpumask;
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/*
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* Do not allow disabling IRQs completely - it's a too easy
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* way to make the system unusable accidentally :-) At least
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* one active CPU still has to be targeted.
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*/
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if (!cpumask_intersects(new_value, cpu_active_mask)) {
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/*
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* Special case for empty set - allow the architecture code
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* to set default SMP affinity.
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*/
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err = irq_select_affinity_usr(irq) ? -EINVAL : count;
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} else {
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err = irq_set_affinity(irq, new_value);
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if (!err)
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err = count;
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}
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free_cpumask:
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free_cpumask_var(new_value);
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return err;
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}
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static ssize_t irq_affinity_proc_write(struct file *file,
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const char __user *buffer, size_t count, loff_t *pos)
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{
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return write_irq_affinity(0, file, buffer, count, pos);
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}
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static ssize_t irq_affinity_list_proc_write(struct file *file,
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const char __user *buffer, size_t count, loff_t *pos)
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{
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return write_irq_affinity(1, file, buffer, count, pos);
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}
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static int irq_affinity_proc_open(struct inode *inode, struct file *file)
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{
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return single_open(file, irq_affinity_proc_show, PDE_DATA(inode));
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}
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static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
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{
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return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));
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}
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static const struct proc_ops irq_affinity_proc_ops = {
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.proc_open = irq_affinity_proc_open,
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.proc_read = seq_read,
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.proc_lseek = seq_lseek,
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.proc_release = single_release,
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.proc_write = irq_affinity_proc_write,
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};
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static const struct proc_ops irq_affinity_list_proc_ops = {
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.proc_open = irq_affinity_list_proc_open,
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.proc_read = seq_read,
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.proc_lseek = seq_lseek,
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.proc_release = single_release,
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.proc_write = irq_affinity_list_proc_write,
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};
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#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
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static int irq_effective_aff_proc_show(struct seq_file *m, void *v)
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{
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return show_irq_affinity(EFFECTIVE, m);
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}
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static int irq_effective_aff_list_proc_show(struct seq_file *m, void *v)
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{
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return show_irq_affinity(EFFECTIVE_LIST, m);
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}
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#endif
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static int default_affinity_show(struct seq_file *m, void *v)
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{
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seq_printf(m, "%*pb\n", cpumask_pr_args(irq_default_affinity));
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return 0;
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}
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static ssize_t default_affinity_write(struct file *file,
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const char __user *buffer, size_t count, loff_t *ppos)
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{
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cpumask_var_t new_value;
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int err;
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if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
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return -ENOMEM;
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err = cpumask_parse_user(buffer, count, new_value);
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if (err)
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goto out;
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/*
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* Do not allow disabling IRQs completely - it's a too easy
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* way to make the system unusable accidentally :-) At least
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* one online CPU still has to be targeted.
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*/
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if (!cpumask_intersects(new_value, cpu_online_mask)) {
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err = -EINVAL;
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goto out;
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}
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cpumask_copy(irq_default_affinity, new_value);
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err = count;
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out:
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free_cpumask_var(new_value);
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return err;
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}
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static int default_affinity_open(struct inode *inode, struct file *file)
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{
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return single_open(file, default_affinity_show, PDE_DATA(inode));
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}
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static const struct proc_ops default_affinity_proc_ops = {
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.proc_open = default_affinity_open,
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.proc_read = seq_read,
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.proc_lseek = seq_lseek,
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.proc_release = single_release,
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.proc_write = default_affinity_write,
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};
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static int irq_node_proc_show(struct seq_file *m, void *v)
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{
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struct irq_desc *desc = irq_to_desc((long) m->private);
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seq_printf(m, "%d\n", irq_desc_get_node(desc));
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return 0;
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}
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#endif
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static int irq_spurious_proc_show(struct seq_file *m, void *v)
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{
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struct irq_desc *desc = irq_to_desc((long) m->private);
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seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
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desc->irq_count, desc->irqs_unhandled,
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jiffies_to_msecs(desc->last_unhandled));
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return 0;
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}
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#define MAX_NAMELEN 128
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static int name_unique(unsigned int irq, struct irqaction *new_action)
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{
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struct irq_desc *desc = irq_to_desc(irq);
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struct irqaction *action;
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unsigned long flags;
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int ret = 1;
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raw_spin_lock_irqsave(&desc->lock, flags);
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for_each_action_of_desc(desc, action) {
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if ((action != new_action) && action->name &&
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!strcmp(new_action->name, action->name)) {
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ret = 0;
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break;
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}
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}
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raw_spin_unlock_irqrestore(&desc->lock, flags);
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return ret;
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}
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void register_handler_proc(unsigned int irq, struct irqaction *action)
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{
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char name [MAX_NAMELEN];
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struct irq_desc *desc = irq_to_desc(irq);
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if (!desc->dir || action->dir || !action->name ||
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!name_unique(irq, action))
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return;
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snprintf(name, MAX_NAMELEN, "%s", action->name);
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/* create /proc/irq/1234/handler/ */
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action->dir = proc_mkdir(name, desc->dir);
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}
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#undef MAX_NAMELEN
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#define MAX_NAMELEN 10
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void register_irq_proc(unsigned int irq, struct irq_desc *desc)
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{
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static DEFINE_MUTEX(register_lock);
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void __maybe_unused *irqp = (void *)(unsigned long) irq;
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char name [MAX_NAMELEN];
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if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip))
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return;
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/*
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* irq directories are registered only when a handler is
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* added, not when the descriptor is created, so multiple
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* tasks might try to register at the same time.
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*/
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mutex_lock(®ister_lock);
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if (desc->dir)
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goto out_unlock;
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sprintf(name, "%d", irq);
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/* create /proc/irq/1234 */
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desc->dir = proc_mkdir(name, root_irq_dir);
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if (!desc->dir)
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goto out_unlock;
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#ifdef CONFIG_SMP
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/* create /proc/irq/<irq>/smp_affinity */
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proc_create_data("smp_affinity", 0644, desc->dir,
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&irq_affinity_proc_ops, irqp);
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/* create /proc/irq/<irq>/affinity_hint */
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proc_create_single_data("affinity_hint", 0444, desc->dir,
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irq_affinity_hint_proc_show, irqp);
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/* create /proc/irq/<irq>/smp_affinity_list */
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proc_create_data("smp_affinity_list", 0644, desc->dir,
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&irq_affinity_list_proc_ops, irqp);
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proc_create_single_data("node", 0444, desc->dir, irq_node_proc_show,
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irqp);
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# ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
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proc_create_single_data("effective_affinity", 0444, desc->dir,
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irq_effective_aff_proc_show, irqp);
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proc_create_single_data("effective_affinity_list", 0444, desc->dir,
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irq_effective_aff_list_proc_show, irqp);
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# endif
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#endif
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proc_create_single_data("spurious", 0444, desc->dir,
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irq_spurious_proc_show, (void *)(long)irq);
|
|
out_unlock:
|
mutex_unlock(®ister_lock);
|
}
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|
void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
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{
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char name [MAX_NAMELEN];
|
|
if (!root_irq_dir || !desc->dir)
|
return;
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#ifdef CONFIG_SMP
|
remove_proc_entry("smp_affinity", desc->dir);
|
remove_proc_entry("affinity_hint", desc->dir);
|
remove_proc_entry("smp_affinity_list", desc->dir);
|
remove_proc_entry("node", desc->dir);
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# ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
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remove_proc_entry("effective_affinity", desc->dir);
|
remove_proc_entry("effective_affinity_list", desc->dir);
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# endif
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#endif
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remove_proc_entry("spurious", desc->dir);
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sprintf(name, "%u", irq);
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remove_proc_entry(name, root_irq_dir);
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}
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|
#undef MAX_NAMELEN
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|
void unregister_handler_proc(unsigned int irq, struct irqaction *action)
|
{
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proc_remove(action->dir);
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}
|
|
static void register_default_affinity_proc(void)
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{
|
#ifdef CONFIG_SMP
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proc_create("irq/default_smp_affinity", 0644, NULL,
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&default_affinity_proc_ops);
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#endif
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}
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void init_irq_proc(void)
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{
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unsigned int irq;
|
struct irq_desc *desc;
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/* create /proc/irq */
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root_irq_dir = proc_mkdir("irq", NULL);
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if (!root_irq_dir)
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return;
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register_default_affinity_proc();
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/*
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* Create entries for all existing IRQs.
|
*/
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for_each_irq_desc(irq, desc)
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register_irq_proc(irq, desc);
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}
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#ifdef CONFIG_GENERIC_IRQ_SHOW
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int __weak arch_show_interrupts(struct seq_file *p, int prec)
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{
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return 0;
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}
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|
#ifndef ACTUAL_NR_IRQS
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# define ACTUAL_NR_IRQS nr_irqs
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#endif
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int show_interrupts(struct seq_file *p, void *v)
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{
|
static int prec;
|
|
unsigned long flags, any_count = 0;
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int i = *(loff_t *) v, j;
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struct irqaction *action;
|
struct irq_desc *desc;
|
|
if (i > ACTUAL_NR_IRQS)
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return 0;
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|
if (i == ACTUAL_NR_IRQS)
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return arch_show_interrupts(p, prec);
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|
/* print header and calculate the width of the first column */
|
if (i == 0) {
|
for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
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j *= 10;
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seq_printf(p, "%*s", prec + 8, "");
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for_each_online_cpu(j)
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seq_printf(p, "CPU%-8d", j);
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seq_putc(p, '\n');
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}
|
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rcu_read_lock();
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desc = irq_to_desc(i);
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if (!desc || irq_settings_is_hidden(desc))
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goto outsparse;
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|
if (desc->kstat_irqs)
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for_each_online_cpu(j)
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any_count |= *per_cpu_ptr(desc->kstat_irqs, j);
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if ((!desc->action || irq_desc_is_chained(desc)) && !any_count)
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goto outsparse;
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seq_printf(p, "%*d: ", prec, i);
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for_each_online_cpu(j)
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seq_printf(p, "%10u ", desc->kstat_irqs ?
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*per_cpu_ptr(desc->kstat_irqs, j) : 0);
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raw_spin_lock_irqsave(&desc->lock, flags);
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if (desc->irq_data.chip) {
|
if (desc->irq_data.chip->irq_print_chip)
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desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
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else if (desc->irq_data.chip->name)
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seq_printf(p, " %8s", desc->irq_data.chip->name);
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else
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seq_printf(p, " %8s", "-");
|
} else {
|
seq_printf(p, " %8s", "None");
|
}
|
if (desc->irq_data.domain)
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seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
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else
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seq_printf(p, " %*s", prec, "");
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#ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
|
seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
|
#endif
|
if (desc->name)
|
seq_printf(p, "-%-8s", desc->name);
|
|
action = desc->action;
|
if (action) {
|
seq_printf(p, " %s", action->name);
|
while ((action = action->next) != NULL)
|
seq_printf(p, ", %s", action->name);
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}
|
|
seq_putc(p, '\n');
|
raw_spin_unlock_irqrestore(&desc->lock, flags);
|
outsparse:
|
rcu_read_unlock();
|
return 0;
|
}
|
#endif
|
