/*
   * linux/arch/m68k/kernel/ints.c -- Linux/m68k general interrupt handling code
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file COPYING in the main directory of this archive
   * for more details.
   *
   * 07/03/96: Timer initialization, and thus mach_sched_init(),
   *           removed from request_irq() and moved to init_time().
   *           We should therefore consider renaming our add_isr() and
   *           remove_isr() to request_irq() and free_irq()
   *           respectively, so they are compliant with the other
   *           architectures.                                     /Jes
   * 11/07/96: Changed all add_/remove_isr() to request_/free_irq() calls.
   *           Removed irq list support, if any machine needs an irq server
   *           it must implement this itself (as it's already done), instead
   *           only default handler are used with mach_default_handler.
   *           request_irq got some flags different from other architectures:
   *           - IRQ_FLG_REPLACE : Replace an existing handler (the default one
   *                               can be replaced without this flag)
   *           - IRQ_FLG_LOCK : handler can't be replaced
   *           There are other machine depending flags, see there
   *           If you want to replace a default handler you should know what
   *           you're doing, since it might handle different other irq sources
   *           which must be served                               /Roman Zippel
   */

  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/sched.h>

  #include <linux/interrupt.h>

  #include <linux/kernel_stat.h>
  #include <linux/errno.h>
  #include <linux/init.h>
  
  #include <asm/setup.h>
  #include <asm/system.h>
  #include <asm/irq.h>
  #include <asm/traps.h>
  #include <asm/page.h>
  #include <asm/machdep.h>

  #include <asm/cacheflush.h>

  #include <asm/irq_regs.h>

  
  #ifdef CONFIG_Q40
  #include <asm/q40ints.h>
  #endif

  extern u32 auto_irqhandler_fixup[];
  extern u32 user_irqhandler_fixup[];
  extern u16 user_irqvec_fixup[];

  /* table for system interrupt handlers */

  static struct irq_node *irq_list[NR_IRQS];
  static struct irq_controller *irq_controller[NR_IRQS];
  static int irq_depth[NR_IRQS];
  
  static int m68k_first_user_vec;

  
  static struct irq_controller auto_irq_controller = {
  	.name		= "auto",
  	.lock		= SPIN_LOCK_UNLOCKED,
  	.startup	= m68k_irq_startup,
  	.shutdown	= m68k_irq_shutdown,
  };

  static struct irq_controller user_irq_controller = {
  	.name		= "user",
  	.lock		= SPIN_LOCK_UNLOCKED,
  	.startup	= m68k_irq_startup,
  	.shutdown	= m68k_irq_shutdown,

  };

  #define NUM_IRQ_NODES 100
  static irq_node_t nodes[NUM_IRQ_NODES];

  /*
   * void init_IRQ(void)
   *
   * Parameters:	None
   *
   * Returns:	Nothing
   *
   * This function should be called during kernel startup to initialize
   * the IRQ handling routines.
   */
  
  void __init init_IRQ(void)
  {
  	int i;

  	/* assembly irq entry code relies on this... */
  	if (HARDIRQ_MASK != 0x00ff0000) {
  		extern void hardirq_mask_is_broken(void);
  		hardirq_mask_is_broken();
  	}

  	for (i = IRQ_AUTO_1; i <= IRQ_AUTO_7; i++)

  		irq_controller[i] = &auto_irq_controller;

  	mach_init_IRQ();
  }
  
  /**
   * m68k_setup_auto_interrupt
   * @handler: called from auto vector interrupts
   *
   * setup the handler to be called from auto vector interrupts instead of the

   * standard __m68k_handle_int(), it will be called with irq numbers in the range

   * from IRQ_AUTO_1 - IRQ_AUTO_7.
   */
  void __init m68k_setup_auto_interrupt(void (*handler)(unsigned int, struct pt_regs *))
  {
  	if (handler)
  		*auto_irqhandler_fixup = (u32)handler;
  	flush_icache();
  }
  
  /**
   * m68k_setup_user_interrupt
   * @vec: first user vector interrupt to handle
   * @cnt: number of active user vector interrupts
   * @handler: called from user vector interrupts
   *
   * setup user vector interrupts, this includes activating the specified range
   * of interrupts, only then these interrupts can be requested (note: this is
   * different from auto vector interrupts). An optional handler can be installed

   * to be called instead of the default __m68k_handle_int(), it will be called

   * with irq numbers starting from IRQ_USER.
   */
  void __init m68k_setup_user_interrupt(unsigned int vec, unsigned int cnt,
  				      void (*handler)(unsigned int, struct pt_regs *))
  {
  	int i;

  	BUG_ON(IRQ_USER + cnt >= NR_IRQS);

  	m68k_first_user_vec = vec;
  	for (i = 0; i < cnt; i++)
  		irq_controller[IRQ_USER + i] = &user_irq_controller;
  	*user_irqvec_fixup = vec - IRQ_USER;
  	if (handler)
  		*user_irqhandler_fixup = (u32)handler;
  	flush_icache();
  }
  
  /**
   * m68k_setup_irq_controller
   * @contr: irq controller which controls specified irq
   * @irq: first irq to be managed by the controller
   *
   * Change the controller for the specified range of irq, which will be used to
   * manage these irq. auto/user irq already have a default controller, which can
   * be changed as well, but the controller probably should use m68k_irq_startup/
   * m68k_irq_shutdown.
   */
  void m68k_setup_irq_controller(struct irq_controller *contr, unsigned int irq,
  			       unsigned int cnt)
  {
  	int i;
  
  	for (i = 0; i < cnt; i++)
  		irq_controller[irq + i] = contr;

  }
  
  irq_node_t *new_irq_node(void)
  {
  	irq_node_t *node;
  	short i;

  	for (node = nodes, i = NUM_IRQ_NODES-1; i >= 0; node++, i--) {
  		if (!node->handler) {
  			memset(node, 0, sizeof(*node));

  			return node;

  		}
  	}

  
  	printk ("new_irq_node: out of nodes
  ");
  	return NULL;
  }

  int setup_irq(unsigned int irq, struct irq_node *node)

  {

  	struct irq_controller *contr;
  	struct irq_node **prev;
  	unsigned long flags;

  	if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {

  		printk("%s: Incorrect IRQ %d from %s
  ",

  		       __FUNCTION__, irq, node->devname);

  		return -ENXIO;
  	}

  	spin_lock_irqsave(&contr->lock, flags);
  
  	prev = irq_list + irq;
  	if (*prev) {
  		/* Can't share interrupts unless both agree to */

  		if (!((*prev)->flags & node->flags & IRQF_SHARED)) {

  			spin_unlock_irqrestore(&contr->lock, flags);

  			return -EBUSY;
  		}

  		while (*prev)
  			prev = &(*prev)->next;

  	}

  	if (!irq_list[irq]) {
  		if (contr->startup)
  			contr->startup(irq);
  		else
  			contr->enable(irq);
  	}
  	node->next = NULL;
  	*prev = node;
  
  	spin_unlock_irqrestore(&contr->lock, flags);

  	return 0;
  }

  int request_irq(unsigned int irq,

  		irq_handler_t handler,

  		unsigned long flags, const char *devname, void *dev_id)

  {
  	struct irq_node *node;
  	int res;
  
  	node = new_irq_node();
  	if (!node)
  		return -ENOMEM;
  
  	node->handler = handler;
  	node->flags   = flags;
  	node->dev_id  = dev_id;
  	node->devname = devname;
  
  	res = setup_irq(irq, node);
  	if (res)
  		node->handler = NULL;
  
  	return res;
  }

  EXPORT_SYMBOL(request_irq);
  
  void free_irq(unsigned int irq, void *dev_id)

  {

  	struct irq_controller *contr;
  	struct irq_node **p, *node;
  	unsigned long flags;

  	if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {

  		printk("%s: Incorrect IRQ %d
  ", __FUNCTION__, irq);
  		return;
  	}

  	spin_lock_irqsave(&contr->lock, flags);
  
  	p = irq_list + irq;
  	while ((node = *p)) {
  		if (node->dev_id == dev_id)
  			break;
  		p = &node->next;
  	}
  
  	if (node) {
  		*p = node->next;
  		node->handler = NULL;
  	} else
  		printk("%s: Removing probably wrong IRQ %d
  ",
  		       __FUNCTION__, irq);

  	if (!irq_list[irq]) {
  		if (contr->shutdown)
  			contr->shutdown(irq);
  		else
  			contr->disable(irq);
  	}
  
  	spin_unlock_irqrestore(&contr->lock, flags);
  }
  
  EXPORT_SYMBOL(free_irq);
  
  void enable_irq(unsigned int irq)
  {
  	struct irq_controller *contr;
  	unsigned long flags;
  
  	if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
  		printk("%s: Incorrect IRQ %d
  ",
  		       __FUNCTION__, irq);
  		return;
  	}
  
  	spin_lock_irqsave(&contr->lock, flags);
  	if (irq_depth[irq]) {
  		if (!--irq_depth[irq]) {
  			if (contr->enable)
  				contr->enable(irq);
  		}
  	} else
  		WARN_ON(1);
  	spin_unlock_irqrestore(&contr->lock, flags);
  }
  
  EXPORT_SYMBOL(enable_irq);

  void disable_irq(unsigned int irq)
  {
  	struct irq_controller *contr;
  	unsigned long flags;
  
  	if (irq >= NR_IRQS || !(contr = irq_controller[irq])) {
  		printk("%s: Incorrect IRQ %d
  ",
  		       __FUNCTION__, irq);
  		return;
  	}
  
  	spin_lock_irqsave(&contr->lock, flags);
  	if (!irq_depth[irq]++) {
  		if (contr->disable)
  			contr->disable(irq);
  	}

  	spin_unlock_irqrestore(&contr->lock, flags);

  }

  EXPORT_SYMBOL(disable_irq);

  int m68k_irq_startup(unsigned int irq)
  {
  	if (irq <= IRQ_AUTO_7)
  		vectors[VEC_SPUR + irq] = auto_inthandler;

  	else
  		vectors[m68k_first_user_vec + irq - IRQ_USER] = user_inthandler;

  	return 0;
  }
  
  void m68k_irq_shutdown(unsigned int irq)
  {
  	if (irq <= IRQ_AUTO_7)
  		vectors[VEC_SPUR + irq] = bad_inthandler;

  	else
  		vectors[m68k_first_user_vec + irq - IRQ_USER] = bad_inthandler;

  }

  /*
   * Do we need these probe functions on the m68k?
   *
   *  ... may be useful with ISA devices
   */
  unsigned long probe_irq_on (void)
  {
  #ifdef CONFIG_Q40
  	if (MACH_IS_Q40)
  		return q40_probe_irq_on();
  #endif
  	return 0;
  }
  
  EXPORT_SYMBOL(probe_irq_on);
  
  int probe_irq_off (unsigned long irqs)
  {
  #ifdef CONFIG_Q40
  	if (MACH_IS_Q40)
  		return q40_probe_irq_off(irqs);
  #endif
  	return 0;
  }
  
  EXPORT_SYMBOL(probe_irq_off);

  unsigned int irq_canonicalize(unsigned int irq)

  {

  #ifdef CONFIG_Q40
  	if (MACH_IS_Q40 && irq == 11)
  		irq = 10;
  #endif
  	return irq;

  }

  EXPORT_SYMBOL(irq_canonicalize);

  asmlinkage void m68k_handle_int(unsigned int irq)

  {

  	struct irq_node *node;

  	kstat_cpu(0).irqs[irq]++;

  	node = irq_list[irq];
  	do {

  		node->handler(irq, node->dev_id);

  		node = node->next;
  	} while (node);

  }

  asmlinkage void __m68k_handle_int(unsigned int irq, struct pt_regs *regs)
  {
  	struct pt_regs *old_regs;
  	old_regs = set_irq_regs(regs);
  	m68k_handle_int(irq);
  	set_irq_regs(old_regs);
  }

  asmlinkage void handle_badint(struct pt_regs *regs)
  {
  	kstat_cpu(0).irqs[0]++;
  	printk("unexpected interrupt from %u
  ", regs->vector);

  }
  
  int show_interrupts(struct seq_file *p, void *v)
  {

  	struct irq_controller *contr;
  	struct irq_node *node;

  	int i = *(loff_t *) v;
  
  	/* autovector interrupts */

  	if (irq_list[i]) {

  		contr = irq_controller[i];
  		node = irq_list[i];

  		seq_printf(p, "%-8s %3u: %10u %s", contr->name, i, kstat_cpu(0).irqs[i], node->devname);

  		while ((node = node->next))
  			seq_printf(p, ", %s", node->devname);
  		seq_puts(p, "
  ");

  	}

  	return 0;
  }
  
  void init_irq_proc(void)
  {
  	/* Insert /proc/irq driver here */
  }