/*
   * 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 "internals.h"

  static struct proc_dir_entry *root_irq_dir;

  
  #ifdef CONFIG_SMP

  static int irq_affinity_proc_show(struct seq_file *m, void *v)

  {

  	struct irq_desc *desc = irq_to_desc((long)m->private);

  	const struct cpumask *mask = desc->affinity;

  
  #ifdef CONFIG_GENERIC_PENDING_IRQ
  	if (desc->status & IRQ_MOVE_PENDING)

  		mask = desc->pending_mask;

  #endif

  	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 ssize_t irq_affinity_proc_write(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_to_desc(irq)->chip->set_affinity || no_irq_affinity ||

  	    irq_balancing_disabled(irq))

  		return -EIO;

  	if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
  		return -ENOMEM;
  
  	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) ? -EINVAL : count;
  	} else {
  		irq_set_affinity(irq, new_value);
  		err = count;
  	}
  
  free_cpumask:
  	free_cpumask_var(new_value);
  	return err;

  }

  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_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 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(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
  ", desc->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
  " "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, NULL);

  }

  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->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);

  	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);

  }
  
  #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);

  	}

  }