/*
   * 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"

  /*
   * Access rules:
   *
   * procfs protects read/write of /proc/irq/N/ files against a
   * concurrent free of the interrupt descriptor. remove_proc_entry()
   * immediately prevents new read/writes to happen and waits for
   * already running read/write functions to complete.
   *
   * We remove the proc entries first and then delete the interrupt
   * descriptor from the radix tree and free it. So it is guaranteed
   * that irq_to_desc(N) is valid as long as the read/writes are
   * permitted by procfs.
   *
   * The read from /proc/interrupts is a different problem because there
   * is no protection. So the lookup and the access to irqdesc
   * information must be protected by sparse_irq_lock.
   */

  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, '
  ');
  	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, '
  ');
  	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_DATA(file_inode(file));

  	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_DATA(inode));

  }

  static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
  {

  	return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));

  }

  static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
  {

  	return single_open(file, irq_affinity_hint_proc_show, PDE_DATA(inode));

  }

  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, '
  ');
  	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_DATA(inode));

  }
  
  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
  ", 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_DATA(inode));

  }
  
  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
  " "unhandled %u
  " "last_unhandled %u ms
  ",
  		   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_DATA(inode));

  }

  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", 0644, desc->dir,

  			 &irq_affinity_proc_fops, (void *)(long)irq);

  	/* create /proc/irq/<irq>/affinity_hint */

  	proc_create_data("affinity_hint", 0444, desc->dir,

  			 &irq_affinity_hint_proc_fops, (void *)(long)irq);

  	/* create /proc/irq/<irq>/smp_affinity_list */

  	proc_create_data("smp_affinity_list", 0644, 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)
  {

  	proc_remove(action->dir);

  }

  static void register_default_affinity_proc(void)

  {
  #ifdef CONFIG_SMP

  	proc_create("irq/default_smp_affinity", 0644, 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, '
  ');
  	}

  	irq_lock_sparse();

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

  		goto outsparse;

  
  	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");
  	}

  	if (desc->irq_data.domain)
  		seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);

  #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, '
  ');
  out:
  	raw_spin_unlock_irqrestore(&desc->lock, flags);

  outsparse:
  	irq_unlock_sparse();

  	return 0;
  }
  #endif