proc.c

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/*
 * linux/kernel/irq/proc.c
 *
 * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
 *
 * This file contains the /proc/irq/ handling code.
 */

#include <linux/irq.h>
#include <linux/gfp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>

#include "internals.h"

static struct proc_dir_entry *root_irq_dir;

#ifdef CONFIG_SMP

static int show_irq_affinity(int type, struct seq_file *m, void *v)
{
    struct irq_desc *desc = irq_to_desc((long)m->private);
    const struct cpumask *mask = desc->irq_data.affinity;

#ifdef CONFIG_GENERIC_PENDING_IRQ
    if (irqd_is_setaffinity_pending(&desc->irq_data))
        mask = desc->pending_mask;
#endif
    if (type)
        seq_cpumask_list(m, mask);
    else
        seq_cpumask(m, mask);
    seq_putc(m, '\n');
    return 0;
}

static int irq_affinity_hint_proc_show(struct seq_file *m, void *v)
{
    struct irq_desc *desc = irq_to_desc((long)m->private);
    unsigned long flags;
    cpumask_var_t mask;

    if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
        return -ENOMEM;

    raw_spin_lock_irqsave(&desc->lock, flags);
    if (desc->affinity_hint)
        cpumask_copy(mask, desc->affinity_hint);
    raw_spin_unlock_irqrestore(&desc->lock, flags);

    seq_cpumask(m, mask);
    seq_putc(m, '\n');
    free_cpumask_var(mask);

    return 0;
}

#ifndef is_affinity_mask_valid
#define is_affinity_mask_valid(val) 1
#endif

int no_irq_affinity;
static int irq_affinity_proc_show(struct seq_file *m, void *v)
{
    return show_irq_affinity(0, m, v);
}

static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
{
    return show_irq_affinity(1, m, v);
}


static ssize_t write_irq_affinity(int type, struct file *file,
        const char __user *buffer, size_t count, loff_t *pos)
{
    unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
    cpumask_var_t new_value;
    int err;

    if (!irq_can_set_affinity(irq) || no_irq_affinity)
        return -EIO;

    if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
        return -ENOMEM;

    if (type)
        err = cpumask_parselist_user(buffer, count, new_value);
    else
        err = cpumask_parse_user(buffer, count, new_value);
    if (err)
        goto free_cpumask;

    if (!is_affinity_mask_valid(new_value)) {
        err = -EINVAL;
        goto free_cpumask;
    }

    /*
     * Do not allow disabling IRQs completely - it's a too easy
     * way to make the system unusable accidentally :-) At least
     * one online CPU still has to be targeted.
     */
    if (!cpumask_intersects(new_value, cpu_online_mask)) {
        /* Special case for empty set - allow the architecture
           code to set default SMP affinity. */
        err = irq_select_affinity_usr(irq, new_value) ? -EINVAL : count;
    } else {
        irq_set_affinity(irq, new_value);
        err = count;
    }

free_cpumask:
    free_cpumask_var(new_value);
    return err;
}

static ssize_t irq_affinity_proc_write(struct file *file,
        const char __user *buffer, size_t count, loff_t *pos)
{
    return write_irq_affinity(0, file, buffer, count, pos);
}

static ssize_t irq_affinity_list_proc_write(struct file *file,
        const char __user *buffer, size_t count, loff_t *pos)
{
    return write_irq_affinity(1, file, buffer, count, pos);
}

static int irq_affinity_proc_open(struct inode *inode, struct file *file)
{
    return single_open(file, irq_affinity_proc_show, PDE(inode)->data);
}

static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
{
    return single_open(file, irq_affinity_list_proc_show, PDE(inode)->data);
}

static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
{
    return single_open(file, irq_affinity_hint_proc_show, PDE(inode)->data);
}

static const struct file_operations irq_affinity_proc_fops = {
    .open       = irq_affinity_proc_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
    .write      = irq_affinity_proc_write,
};

static const struct file_operations irq_affinity_hint_proc_fops = {
    .open       = irq_affinity_hint_proc_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
};

static const struct file_operations irq_affinity_list_proc_fops = {
    .open       = irq_affinity_list_proc_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
    .write      = irq_affinity_list_proc_write,
};

static int default_affinity_show(struct seq_file *m, void *v)
{
    seq_cpumask(m, irq_default_affinity);
    seq_putc(m, '\n');
    return 0;
}

static ssize_t default_affinity_write(struct file *file,
        const char __user *buffer, size_t count, loff_t *ppos)
{
    cpumask_var_t new_value;
    int err;

    if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
        return -ENOMEM;

    err = cpumask_parse_user(buffer, count, new_value);
    if (err)
        goto out;

    if (!is_affinity_mask_valid(new_value)) {
        err = -EINVAL;
        goto out;
    }

    /*
     * Do not allow disabling IRQs completely - it's a too easy
     * way to make the system unusable accidentally :-) At least
     * one online CPU still has to be targeted.
     */
    if (!cpumask_intersects(new_value, cpu_online_mask)) {
        err = -EINVAL;
        goto out;
    }

    cpumask_copy(irq_default_affinity, new_value);
    err = count;

out:
    free_cpumask_var(new_value);
    return err;
}

static int default_affinity_open(struct inode *inode, struct file *file)
{
    return single_open(file, default_affinity_show, PDE(inode)->data);
}

static const struct file_operations default_affinity_proc_fops = {
    .open       = default_affinity_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
    .write      = default_affinity_write,
};

static int irq_node_proc_show(struct seq_file *m, void *v)
{
    struct irq_desc *desc = irq_to_desc((long) m->private);

    seq_printf(m, "%d\n", desc->irq_data.node);
    return 0;
}

static int irq_node_proc_open(struct inode *inode, struct file *file)
{
    return single_open(file, irq_node_proc_show, PDE(inode)->data);
}

static const struct file_operations irq_node_proc_fops = {
    .open       = irq_node_proc_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
};
#endif

static int irq_spurious_proc_show(struct seq_file *m, void *v)
{
    struct irq_desc *desc = irq_to_desc((long) m->private);

    seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n",
           desc->irq_count, desc->irqs_unhandled,
           jiffies_to_msecs(desc->last_unhandled));
    return 0;
}

static int irq_spurious_proc_open(struct inode *inode, struct file *file)
{
    return single_open(file, irq_spurious_proc_show, PDE(inode)->data);
}

static const struct file_operations irq_spurious_proc_fops = {
    .open       = irq_spurious_proc_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
};

#define MAX_NAMELEN 128

static int name_unique(unsigned int irq, struct irqaction *new_action)
{
    struct irq_desc *desc = irq_to_desc(irq);
    struct irqaction *action;
    unsigned long flags;
    int ret = 1;

    raw_spin_lock_irqsave(&desc->lock, flags);
    for (action = desc->action ; action; action = action->next) {
        if ((action != new_action) && action->name &&
                !strcmp(new_action->name, action->name)) {
            ret = 0;
            break;
        }
    }
    raw_spin_unlock_irqrestore(&desc->lock, flags);
    return ret;
}

void register_handler_proc(unsigned int irq, struct irqaction *action)
{
    char name [MAX_NAMELEN];
    struct irq_desc *desc = irq_to_desc(irq);

    if (!desc->dir || action->dir || !action->name ||
                    !name_unique(irq, action))
        return;

    memset(name, 0, MAX_NAMELEN);
    snprintf(name, MAX_NAMELEN, "%s", action->name);

    /* create /proc/irq/1234/handler/ */
    action->dir = proc_mkdir(name, desc->dir);
}

#undef MAX_NAMELEN

#define MAX_NAMELEN 10

void register_irq_proc(unsigned int irq, struct irq_desc *desc)
{
    char name [MAX_NAMELEN];

    if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip) || desc->dir)
        return;

    memset(name, 0, MAX_NAMELEN);
    sprintf(name, "%d", irq);

    /* create /proc/irq/1234 */
    desc->dir = proc_mkdir(name, root_irq_dir);
    if (!desc->dir)
        return;

#ifdef CONFIG_SMP
    /* create /proc/irq/<irq>/smp_affinity */
    proc_create_data("smp_affinity", 0600, desc->dir,
             &irq_affinity_proc_fops, (void *)(long)irq);

    /* create /proc/irq/<irq>/affinity_hint */
    proc_create_data("affinity_hint", 0400, desc->dir,
             &irq_affinity_hint_proc_fops, (void *)(long)irq);

    /* create /proc/irq/<irq>/smp_affinity_list */
    proc_create_data("smp_affinity_list", 0600, desc->dir,
             &irq_affinity_list_proc_fops, (void *)(long)irq);

    proc_create_data("node", 0444, desc->dir,
             &irq_node_proc_fops, (void *)(long)irq);
#endif

    proc_create_data("spurious", 0444, desc->dir,
             &irq_spurious_proc_fops, (void *)(long)irq);
}

void unregister_irq_proc(unsigned int irq, struct irq_desc *desc)
{
    char name [MAX_NAMELEN];

    if (!root_irq_dir || !desc->dir)
        return;
#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);
#endif
    remove_proc_entry("spurious", desc->dir);

    memset(name, 0, MAX_NAMELEN);
    sprintf(name, "%u", irq);
    remove_proc_entry(name, root_irq_dir);
}

#undef MAX_NAMELEN

void unregister_handler_proc(unsigned int irq, struct irqaction *action)
{
    if (action->dir) {
        struct irq_desc *desc = irq_to_desc(irq);

        remove_proc_entry(action->dir->name, desc->dir);
    }
}

static void register_default_affinity_proc(void)
{
#ifdef CONFIG_SMP
    proc_create("irq/default_smp_affinity", 0600, NULL,
            &default_affinity_proc_fops);
#endif
}

void init_irq_proc(void)
{
    unsigned int irq;
    struct irq_desc *desc;

    /* create /proc/irq */
    root_irq_dir = proc_mkdir("irq", NULL);
    if (!root_irq_dir)
        return;

    register_default_affinity_proc();

    /*
     * Create entries for all existing IRQs.
     */
    for_each_irq_desc(irq, desc) {
        if (!desc)
            continue;

        register_irq_proc(irq, desc);
    }
}

#ifdef CONFIG_GENERIC_IRQ_SHOW

int __weak arch_show_interrupts(struct seq_file *p, int prec)
{
    return 0;
}

#ifndef ACTUAL_NR_IRQS
# define ACTUAL_NR_IRQS nr_irqs
#endif

int show_interrupts(struct seq_file *p, void *v)
{
    static int prec;

    unsigned long flags, any_count = 0;
    int i = *(loff_t *) v, j;
    struct irqaction *action;
    struct irq_desc *desc;

    if (i > ACTUAL_NR_IRQS)
        return 0;

    if (i == ACTUAL_NR_IRQS)
        return arch_show_interrupts(p, prec);

    /* print header and calculate the width of the first column */
    if (i == 0) {
        for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
            j *= 10;

        seq_printf(p, "%*s", prec + 8, "");
        for_each_online_cpu(j)
            seq_printf(p, "CPU%-8d", j);
        seq_putc(p, '\n');
    }

    desc = irq_to_desc(i);
    if (!desc)
        return 0;

    raw_spin_lock_irqsave(&desc->lock, flags);
    for_each_online_cpu(j)
        any_count |= kstat_irqs_cpu(i, j);
    action = desc->action;
    if (!action && !any_count)
        goto out;

    seq_printf(p, "%*d: ", prec, i);
    for_each_online_cpu(j)
        seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));

    if (desc->irq_data.chip) {
        if (desc->irq_data.chip->irq_print_chip)
            desc->irq_data.chip->irq_print_chip(&desc->irq_data, p);
        else if (desc->irq_data.chip->name)
            seq_printf(p, " %8s", desc->irq_data.chip->name);
        else
            seq_printf(p, " %8s", "-");
    } else {
        seq_printf(p, " %8s", "None");
    }
#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);

    if (action) {
        seq_printf(p, "  %s", action->name);
        while ((action = action->next) != NULL)
            seq_printf(p, ", %s", action->name);
    }

    seq_putc(p, '\n');
out:
    raw_spin_unlock_irqrestore(&desc->lock, flags);
    return 0;
}
#endif