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/*  $Id: irq.c,v 1.1 2005-12-20 09:50:43 jcastillo Exp $

 *  arch/sparc/kernel/irq.c:  Interrupt request handling routines. On the

 *                            Sparc the IRQ's are basically 'cast in stone'

 *                            and you are supposed to probe the prom's device

 *                            node trees to find out who's got which IRQ.

 *

 *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)

 *  Copyright (C) 1995 Miguel de Icaza (miguel@nuclecu.unam.mx)

 *  Copyright (C) 1995 Pete A. Zaitcev (zaitcev@ipmce.su)

 *  Copyright (C) 1996 Dave Redman (djhr@tadpole.co.uk)

 */

#include <linux/config.h>

#include <linux/ptrace.h>

#include <linux/errno.h>

#include <linux/linkage.h>

#include <linux/kernel_stat.h>

#include <linux/signal.h>

#include <linux/sched.h>

#include <linux/interrupt.h>

#include <linux/malloc.h>

#include <asm/ptrace.h>

#include <asm/processor.h>

#include <asm/system.h>

#include <asm/psr.h>

#include <asm/smp.h>

#include <asm/vaddrs.h>

#include <asm/timer.h>

#include <asm/openprom.h>

#include <asm/oplib.h>

#include <asm/traps.h>

#include <asm/irq.h>

#include <asm/io.h>

/*

 * Dave Redman (djhr@tadpole.co.uk)

 *

 * IRQ numbers.. These are no longer restricted to 15..

 *

 * this is done to enable SBUS cards and onboard IO to be masked

 * correctly. using the interrupt level isn't good enough.

 *

 * For example:

 *   A device interrupting at sbus level6 and the Floppy both come in

 *   at IRQ11, but enabling and disabling them requires writing to

 *   different bits in the SLAVIO/SEC.

 *

 * As a result of these changes sun4m machines could now support

 * directed CPU interrupts using the existing enable/disable irq code

 * with tweaks.

 *

 */

static void irq_panic(void)

{

    extern char *cputypval;

    prom_printf("machine: %s doesn't have irq handlers defined!\n",cputypval);

    prom_halt();

}

void (*enable_irq)(unsigned int) = (void (*)(unsigned int)) irq_panic;

void (*disable_irq)(unsigned int) = (void (*)(unsigned int)) irq_panic;

void (*clear_clock_irq)( void ) = irq_panic;

void (*clear_profile_irq)( void ) = irq_panic;

void (*load_profile_irq)( unsigned int ) =  (void (*)(unsigned int)) irq_panic;

void (*init_timers)( void (*)(int, void *,struct pt_regs *)) =

    (void (*)( void (*)(int, void *,struct pt_regs *))) irq_panic;

#ifdef __SMP__

void (*set_cpu_int)(int, int);

void (*clear_cpu_int)(int, int);

void (*set_irq_udt)(int);

#endif

/*

 * Dave Redman (djhr@tadpole.co.uk)

 *

 * There used to be extern calls and hard coded values here.. very sucky!

 * instead, because some of the devices attach very early, I do something

 * equally sucky but at least we'll never try to free statically allocated

 * space or call kmalloc before kmalloc_init :(.

 *

 * In fact it's the timer10 that attaches first.. then timer14

 * then kmalloc_init is called.. then the tty interrupts attach.

 * hmmm....

 *

 */

#define MAX_STATIC_ALLOC        4

static struct irqaction static_irqaction[MAX_STATIC_ALLOC];

static int static_irq_count = 0;

static struct irqaction *irq_action[NR_IRQS+1] = {

          NULL, NULL, NULL, NULL, NULL, NULL , NULL, NULL,

          NULL, NULL, NULL, NULL, NULL, NULL , NULL, NULL

};

int get_irq_list(char *buf)

{

        int i, len = 0;

        struct irqaction * action;

        for (i = 0 ; i < (NR_IRQS+1) ; i++) {

                action = *(i + irq_action);

                if (!action)

                        continue;

                len += sprintf(buf+len, "%2d: %8d %c %s",

                        i, kstat.interrupts[i],

                        (action->flags & SA_INTERRUPT) ? '+' : ' ',

                        action->name);

                for (action=action->next; action; action = action->next) {

                        len += sprintf(buf+len, ",%s %s",

                                (action->flags & SA_INTERRUPT) ? " +" : "",

                                action->name);

                }

                len += sprintf(buf+len, "\n");

        }

        return len;

}

void free_irq(unsigned int irq, void *dev_id)

{

        struct irqaction * action;

        struct irqaction * tmp = NULL;

        unsigned long flags;

        unsigned int cpu_irq;

        cpu_irq = irq & NR_IRQS;

        action = *(cpu_irq + irq_action);

        if (cpu_irq > 14) {  /* 14 irq levels on the sparc */

                printk("Trying to free bogus IRQ %d\n", irq);

                return;

        }

        if (!action->handler) {

                printk("Trying to free free IRQ%d\n",irq);

                return;

        }

        if (dev_id) {

                for (; action; action = action->next) {

                        if (action->dev_id == dev_id) break;

                        tmp = action;

                }

                if (!action) {

                        printk("Trying to free free shared IRQ%d\n",irq);

                        return;

                }

        } else if (action->flags & SA_SHIRQ) {

                printk("Trying to free shared IRQ%d with NULL device ID\n", irq);

                return;

        }

        if (action->flags & SA_STATIC_ALLOC)

        {

            /* This interrupt is marked as specially allocated

             * so it is a bad idea to free it.

             */

            printk("Attempt to free statically allocated IRQ%d (%s)\n",

                   irq, action->name);

            return;

        }

        save_flags(flags); cli();

        if (action && tmp)

                tmp->next = action->next;

        else

                *(cpu_irq + irq_action) = action->next;

        kfree_s(action, sizeof(struct irqaction));

        if (!(*(cpu_irq + irq_action)))

                disable_irq(irq);

        restore_flags(flags);

}

void unexpected_irq(int irq, void *dev_id, struct pt_regs * regs)

{

        int i;

        struct irqaction * action;

        unsigned int cpu_irq;

        cpu_irq = irq & NR_IRQS;

        action = *(cpu_irq + irq_action);

        printk("IO device interrupt, irq = %d\n", irq);

        printk("PC = %08lx NPC = %08lx FP=%08lx\n", regs->pc,

                    regs->npc, regs->u_regs[14]);

        printk("Expecting: ");

        for (i = 0; i < 16; i++)

                if (action->handler)

                        prom_printf("[%s:%d:0x%x] ", action->name, (int) i,

                                    (unsigned int) action->handler);

        printk("AIEEE\n");

        panic("bogus interrupt received");

}

void handler_irq(int irq, struct pt_regs * regs)

{

        struct irqaction * action;

        unsigned int cpu_irq;

        cpu_irq = irq & NR_IRQS;

        action = *(cpu_irq + irq_action);

        kstat.interrupts[cpu_irq]++;

#if 0

        printk("I<%d,%d,%d>", smp_processor_id(), irq, smp_proc_in_lock[smp_processor_id()]);

#endif

        while (action) {

                if (!action->handler)

                        unexpected_irq(irq, action->dev_id, regs);

                else

                        action->handler(irq, action->dev_id, regs);

                action = action->next;

        }

}

/*

 * do_IRQ handles IRQ's that have been installed without the

 * SA_INTERRUPT flag: it uses the full signal-handling return

 * and runs with other interrupts enabled. All relatively slow

 * IRQ's should use this format: notably the keyboard/timer

 * routines.

 */

asmlinkage void do_IRQ(int irq, struct pt_regs * regs)

{

        struct irqaction * action;

        unsigned int cpu_irq;

        cpu_irq = irq & NR_IRQS;

        action = *(cpu_irq + irq_action);

        kstat.interrupts[cpu_irq]++;

        while (action) {

                action->handler(irq, action->dev_id, regs);

                action = action->next;

        }

}

/*

 * do_fast_IRQ handles IRQ's that don't need the fancy interrupt return

 * stuff - the handler is also running with interrupts disabled unless

 * it explicitly enables them later.

 */

asmlinkage void do_fast_IRQ(int irq)

{

        kstat.interrupts[irq&NR_IRQS]++;

        printk("Got FAST_IRQ number %04lx\n", (long unsigned int) irq);

        return;

}

/* Fast IRQ's on the Sparc can only have one routine attached to them,

 * thus no sharing possible.

 */

int request_fast_irq(unsigned int irq,

                     void (*handler)(int, void *, struct pt_regs *),

                     unsigned long irqflags, const char *devname)

{

        struct irqaction *action;

        unsigned long flags;

        unsigned int cpu_irq;

        cpu_irq = irq & NR_IRQS;

        if(cpu_irq > 14)

                return -EINVAL;

        if(!handler)

                return -EINVAL;

        action = *(cpu_irq + irq_action);

        if(action) {

                if(action->flags & SA_SHIRQ)

                        panic("Trying to register fast irq when already shared.\n");

                if(irqflags & SA_SHIRQ)

                        panic("Trying to register fast irq as shared.\n");

                /* Anyway, someone already owns it so cannot be made fast. */

                return -EBUSY;

        }

        save_flags(flags); cli();

        /* If this is flagged as statically allocated then we use our

         * private struct which is never freed.

         */

        if (irqflags & SA_STATIC_ALLOC)

            if (static_irq_count < MAX_STATIC_ALLOC)

                action = &static_irqaction[static_irq_count++];

            else

                printk("Fast IRQ%d (%s) SA_STATIC_ALLOC failed using kmalloc\n",

                       irq, devname);

        if (action == NULL)

            action = (struct irqaction *)kmalloc(sizeof(struct irqaction),

                                                 GFP_KERNEL);

        if (!action) {

                restore_flags(flags);

                return -ENOMEM;

        }

        /* Dork with trap table if we get this far. */

        sparc_ttable[SP_TRAP_IRQ1+(cpu_irq-1)].inst_one =

                SPARC_BRANCH((unsigned long) handler,

                             (unsigned long) &sparc_ttable[SP_TRAP_IRQ1+(irq-1)].inst_one);

        sparc_ttable[SP_TRAP_IRQ1+(cpu_irq-1)].inst_two = SPARC_RD_PSR_L0;

        sparc_ttable[SP_TRAP_IRQ1+(cpu_irq-1)].inst_three = SPARC_NOP;

        sparc_ttable[SP_TRAP_IRQ1+(cpu_irq-1)].inst_four = SPARC_NOP;

        action->handler = handler;

        action->flags = irqflags;

        action->mask = 0;

        action->name = devname;

        action->dev_id = NULL;

        *(cpu_irq + irq_action) = action;

        enable_irq(irq);

        restore_flags(flags);

        return 0;

}

int request_irq(unsigned int irq,

                void (*handler)(int, void *, struct pt_regs *),

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

{

        struct irqaction * action, *tmp = NULL;

        unsigned long flags;

        unsigned int cpu_irq;

        cpu_irq = irq & NR_IRQS;

        if(cpu_irq > 14)

                return -EINVAL;

        if (!handler)

            return -EINVAL;

        action = *(cpu_irq + irq_action);

        if (action) {

                if ((action->flags & SA_SHIRQ) && (irqflags & SA_SHIRQ)) {

                        for (tmp = action; tmp->next; tmp = tmp->next);

                } else {

                        return -EBUSY;

                }

                if ((action->flags & SA_INTERRUPT) ^ (irqflags & SA_INTERRUPT)) {

                        printk("Attempt to mix fast and slow interrupts on IRQ%d denied\n", irq);

                        return -EBUSY;

                }

        }

        save_flags(flags); cli();

        /* If this is flagged as statically allocated then we use our

         * private struct which is never freed.

         */

        if (irqflags & SA_STATIC_ALLOC)

            if (static_irq_count < MAX_STATIC_ALLOC)

                action = &static_irqaction[static_irq_count++];

            else

                printk("Request for IRQ%d (%s) SA_STATIC_ALLOC failed using kmalloc\n",irq, devname);

        if (action == NULL)

            action = (struct irqaction *)kmalloc(sizeof(struct irqaction),

                                                 GFP_KERNEL);

        if (!action) {

                restore_flags(flags);

                return -ENOMEM;

        }

        action->handler = handler;

        action->flags = irqflags;

        action->mask = 0;

        action->name = devname;

        action->next = NULL;

        action->dev_id = dev_id;

        if (tmp)

                tmp->next = action;

        else

                *(cpu_irq + irq_action) = action;

        enable_irq(irq);

        restore_flags(flags);

        return 0;

}

/* We really don't need these at all on the Sparc.  We only have

 * stubs here because they are exported to modules.

 */

unsigned long probe_irq_on(void)

{

  return 0;

}

int probe_irq_off(unsigned long mask)

{

  return 0;

}

/* djhr

 * This could probably be made indirect too and assigned in the CPU

 * bits of the code. That would be much nicer I think and would also

 * fit in with the idea of being able to tune your kernel for your machine

 * by removing unrequired machine and device support.

 *

 */

void init_IRQ(void)

{

        extern void sun4c_init_IRQ( void );

        extern void sun4m_init_IRQ( void );

#if CONFIG_AP1000

        extern void ap_init_IRQ(void);

        ap_init_IRQ();

        return;

#endif

        switch(sparc_cpu_model) {

        case sun4c:

                sun4c_init_IRQ();

                break;

        case sun4m:

                sun4m_init_IRQ();

                break;

        default:

                prom_printf("Cannot initialize IRQ's on this Sun machine...");

                break;

        }

}