/*
 * 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(auto_irq_controller.lock),
        .startup        = m68k_irq_startup,
        .shutdown       = m68k_irq_shutdown,
};

static struct irq_controller user_irq_controller = {
        .name           = "user",
        .lock           = __SPIN_LOCK_UNLOCKED(user_irq_controller.lock),
        .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\n");
        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\n",
                       __func__, 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\n", __func__, 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\n",
                       __func__, 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\n",
                       __func__, 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\n",
                       __func__, 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);

void disable_irq_nosync(unsigned int irq) __attribute__((alias("disable_irq")));

EXPORT_SYMBOL(disable_irq_nosync);

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\n", 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, "\n");
        }
        return 0;
}

#ifdef CONFIG_PROC_FS
void init_irq_proc(void)
{
        /* Insert /proc/irq driver here */
}
#endif