Import 2.3.50pre1

[davej-history.git] / arch / m68k / amiga / amiints.c

/*
 * linux/arch/m68k/amiga/amiints.c -- Amiga Linux 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.
 *
 * 11/07/96: rewritten interrupt handling, irq lists are exists now only for
 *           this sources where it makes sense (VERTB/PORTS/EXTER) and you must
 *           be careful that dev_id for this sources is unique since this the
 *           only possibility to distinguish between different handlers for
 *           free_irq. irq lists also have different irq flags:
 *           - IRQ_FLG_FAST: handler is inserted at top of list (after other
 *                           fast handlers)
 *           - IRQ_FLG_SLOW: handler is inserted at bottom of list and before
 *                           they're executed irq level is set to the previous
 *                           one, but handlers don't need to be reentrant, if
 *                           reentrance occurred, slow handlers will be just
 *                           called again.
 *           The whole interrupt handling for CIAs is moved to cia.c
 *           /Roman Zippel
 *
 * 07/08/99: rewamp of the interrupt handling - we now have two types of
 *           interrupts, normal and fast handlers, fast handlers being
 *           marked with SA_INTERRUPT and runs with all other interrupts
 *           disabled. Normal interrupts disable their own source but
 *           run with all other interrupt sources enabled.
 *           PORTS and EXTER interrupts are always shared even if the
 *           drivers do not explicitly mark this when calling
 *           request_irq which they really should do.
 *           This is similar to the way interrupts are handled on all
 *           other architectures and makes a ton of sense besides
 *           having the advantage of making it easier to share
 *           drivers.
 *           /Jes
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/kernel_stat.h>
#include <linux/init.h>

#include <asm/system.h>
#include <asm/irq.h>
#include <asm/traps.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>
#include <asm/amipcmcia.h>

extern int cia_request_irq(struct ciabase *base,int irq,
                           void (*handler)(int, void *, struct pt_regs *),
                           unsigned long flags, const char *devname, void *dev_id);
extern void cia_free_irq(struct ciabase *base, unsigned int irq, void *dev_id);
extern void cia_init_IRQ(struct ciabase *base);
extern int cia_get_irq_list(struct ciabase *base, char *buf);

/* irq node variables for amiga interrupt sources */
static irq_node_t *ami_irq_list[AMI_STD_IRQS];

unsigned short ami_intena_vals[AMI_STD_IRQS] = {
        IF_VERTB, IF_COPER, IF_AUD0, IF_AUD1, IF_AUD2, IF_AUD3, IF_BLIT,
        IF_DSKSYN, IF_DSKBLK, IF_RBF, IF_TBE, IF_SOFT, IF_PORTS, IF_EXTER
};
static const unsigned char ami_servers[AMI_STD_IRQS] = {
        1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1
};

static short ami_ablecount[AMI_IRQS];

static void ami_badint(int irq, void *dev_id, struct pt_regs *fp)
{
        num_spurious += 1;
}

/*
 * void amiga_init_IRQ(void)
 *
 * Parameters:  None
 *
 * Returns:     Nothing
 *
 * This function should be called during kernel startup to initialize
 * the amiga IRQ handling routines.
 */

void __init amiga_init_IRQ(void)
{
        int i;

        /* initialize handlers */
        for (i = 0; i < AMI_STD_IRQS; i++) {
                if (ami_servers[i]) {
                        ami_irq_list[i] = NULL;
                } else {
                        ami_irq_list[i] = new_irq_node();
                        ami_irq_list[i]->handler = ami_badint;
                        ami_irq_list[i]->flags   = 0;
                        ami_irq_list[i]->dev_id  = NULL;
                        ami_irq_list[i]->devname = NULL;
                        ami_irq_list[i]->next    = NULL;
                }
        }
        for (i = 0; i < AMI_IRQS; i++)
                ami_ablecount[i] = 0;

        /* turn off PCMCIA interrupts */
        if (AMIGAHW_PRESENT(PCMCIA))
                pcmcia_disable_irq();

        /* turn off all interrupts and enable the master interrupt bit */
        custom.intena = 0x7fff;
        custom.intreq = 0x7fff;
        custom.intena = IF_SETCLR | IF_INTEN;

        cia_init_IRQ(&ciaa_base);
        cia_init_IRQ(&ciab_base);
}

static inline int amiga_insert_irq(irq_node_t **list, irq_node_t *node)
{
        unsigned long flags;
        irq_node_t *cur;

        if (!node->dev_id)
                printk("%s: Warning: dev_id of %s is zero\n",
                       __FUNCTION__, node->devname);

        save_flags(flags);
        cli();

        cur = *list;

        if (node->flags & SA_INTERRUPT) {
                if (node->flags & SA_SHIRQ)
                        return -EBUSY;
                /*
                 * There should never be more than one
                 */
                while (cur && cur->flags & SA_INTERRUPT) {
                        list = &cur->next;
                        cur = cur->next;
                }
        } else {
                while (cur) {
                        list = &cur->next;
                        cur = cur->next;
                }
        }

        node->next = cur;
        *list = node;

        restore_flags(flags);
        return 0;
}

static inline void amiga_delete_irq(irq_node_t **list, void *dev_id)
{
        unsigned long flags;
        irq_node_t *node;

        save_flags(flags);
        cli();

        for (node = *list; node; list = &node->next, node = *list) {
                if (node->dev_id == dev_id) {
                        *list = node->next;
                        /* Mark it as free. */
                        node->handler = NULL;
                        restore_flags(flags);
                        return;
                }
        }
        restore_flags(flags);
        printk ("%s: tried to remove invalid irq\n", __FUNCTION__);
}

/*
 * amiga_request_irq : add an interrupt service routine for a particular
 *                     machine specific interrupt source.
 *                     If the addition was successful, it returns 0.
 */

int amiga_request_irq(unsigned int irq,
                      void (*handler)(int, void *, struct pt_regs *),
                      unsigned long flags, const char *devname, void *dev_id)
{
        irq_node_t *node;
        int error = 0;

        if (irq >= AMI_IRQS) {
                printk ("%s: Unknown IRQ %d from %s\n", __FUNCTION__,
                        irq, devname);
                return -ENXIO;
        }

        if (irq >= IRQ_AMIGA_AUTO)
                return sys_request_irq(irq - IRQ_AMIGA_AUTO, handler,
                                       flags, devname, dev_id);

        if (irq >= IRQ_AMIGA_CIAB)
                return cia_request_irq(&ciab_base, irq - IRQ_AMIGA_CIAB,
                                       handler, flags, devname, dev_id);

        if (irq >= IRQ_AMIGA_CIAA)
                return cia_request_irq(&ciaa_base, irq - IRQ_AMIGA_CIAA,
                                       handler, flags, devname, dev_id);

        /*
         * IRQ_AMIGA_PORTS & IRQ_AMIGA_EXTER defaults to shared,
         * we could add a check here for the SA_SHIRQ flag but all drivers
         * should be aware of sharing anyway.
         */
        if (ami_servers[irq]) {
                if (!(node = new_irq_node()))
                        return -ENOMEM;
                node->handler = handler;
                node->flags   = flags;
                node->dev_id  = dev_id;
                node->devname = devname;
                node->next    = NULL;
                error = amiga_insert_irq(&ami_irq_list[irq], node);
        } else {
                ami_irq_list[irq]->handler = handler;
                ami_irq_list[irq]->flags   = flags;
                ami_irq_list[irq]->dev_id  = dev_id;
                ami_irq_list[irq]->devname = devname;
        }

        /* enable the interrupt */
        if (irq < IRQ_AMIGA_PORTS && !ami_ablecount[irq])
                custom.intena = IF_SETCLR | ami_intena_vals[irq];

        return error;
}

void amiga_free_irq(unsigned int irq, void *dev_id)
{
        if (irq >= AMI_IRQS) {
                printk ("%s: Unknown IRQ %d\n", __FUNCTION__, irq);
                return;
        }

        if (irq >= IRQ_AMIGA_AUTO)
                sys_free_irq(irq - IRQ_AMIGA_AUTO, dev_id);

        if (irq >= IRQ_AMIGA_CIAB) {
                cia_free_irq(&ciab_base, irq - IRQ_AMIGA_CIAB, dev_id);
                return;
        }

        if (irq >= IRQ_AMIGA_CIAA) {
                cia_free_irq(&ciaa_base, irq - IRQ_AMIGA_CIAA, dev_id);
                return;
        }

        if (ami_servers[irq]) {
                amiga_delete_irq(&ami_irq_list[irq], dev_id);
                /* if server list empty, disable the interrupt */
                if (!ami_irq_list[irq] && irq < IRQ_AMIGA_PORTS)
                        custom.intena = ami_intena_vals[irq];
        } else {
                if (ami_irq_list[irq]->dev_id != dev_id)
                        printk("%s: removing probably wrong IRQ %d from %s\n",
                               __FUNCTION__, irq, ami_irq_list[irq]->devname);
                ami_irq_list[irq]->handler = ami_badint;
                ami_irq_list[irq]->flags   = 0;
                ami_irq_list[irq]->dev_id  = NULL;
                ami_irq_list[irq]->devname = NULL;
                custom.intena = ami_intena_vals[irq];
        }
}

/*
 * Enable/disable a particular machine specific interrupt source.
 * Note that this may affect other interrupts in case of a shared interrupt.
 * This function should only be called for a _very_ short time to change some
 * internal data, that may not be changed by the interrupt at the same time.
 * ami_(enable|disable)_irq calls may also be nested.
 */

void amiga_enable_irq(unsigned int irq)
{
        if (irq >= AMI_IRQS) {
                printk("%s: Unknown IRQ %d\n", __FUNCTION__, irq);
                return;
        }

        if (--ami_ablecount[irq])
                return;

        /* No action for auto-vector interrupts */
        if (irq >= IRQ_AMIGA_AUTO){
                printk("%s: Trying to enable auto-vector IRQ %i\n",
                       __FUNCTION__, irq - IRQ_AMIGA_AUTO);
                return;
        }

        if (irq >= IRQ_AMIGA_CIAB) {
                cia_set_irq(&ciab_base, (1 << (irq - IRQ_AMIGA_CIAB)));
                cia_able_irq(&ciab_base, CIA_ICR_SETCLR |
                             (1 << (irq - IRQ_AMIGA_CIAB)));
                return;
        }

        if (irq >= IRQ_AMIGA_CIAA) {
                cia_set_irq(&ciaa_base, (1 << (irq - IRQ_AMIGA_CIAA)));
                cia_able_irq(&ciaa_base, CIA_ICR_SETCLR |
                             (1 << (irq - IRQ_AMIGA_CIAA)));
                return;
        }

        /* enable the interrupt */
        custom.intena = IF_SETCLR | ami_intena_vals[irq];
}

void amiga_disable_irq(unsigned int irq)
{
        if (irq >= AMI_IRQS) {
                printk("%s: Unknown IRQ %d\n", __FUNCTION__, irq);
                return;
        }

        if (ami_ablecount[irq]++)
                return;

        /* No action for auto-vector interrupts */
        if (irq >= IRQ_AMIGA_AUTO) {
                printk("%s: Trying to disable auto-vector IRQ %i\n",
                       __FUNCTION__, irq - IRQ_AMIGA_AUTO);
                return;
        }

        if (irq >= IRQ_AMIGA_CIAB) {
                cia_able_irq(&ciab_base, 1 << (irq - IRQ_AMIGA_CIAB));
                return;
        }

        if (irq >= IRQ_AMIGA_CIAA) {
                cia_able_irq(&ciaa_base, 1 << (irq - IRQ_AMIGA_CIAA));
                return;
        }

        /* disable the interrupt */
        custom.intena = ami_intena_vals[irq];
}

inline void amiga_do_irq(int irq, struct pt_regs *fp)
{
        kstat.irqs[0][SYS_IRQS + irq]++;
        ami_irq_list[irq]->handler(irq, ami_irq_list[irq]->dev_id, fp);
}

void amiga_do_irq_list(int irq, struct pt_regs *fp, struct irq_server *server)
{
        irq_node_t *node, *slow_nodes;
        unsigned short flags, intena;

        kstat.irqs[0][SYS_IRQS + irq]++;
        if (server->count++)
                server->reentrance = 1;

        intena = ami_intena_vals[irq];
        custom.intreq = intena;

        /* serve fast handler if present - there can only be one of these */
        node = ami_irq_list[irq];

        /*
         * Timer interrupts show up like this
         */
        if (!node) {
                server->count--;
                return;
        }

        if (node && (node->flags & SA_INTERRUPT)) {
                save_flags(flags);
                cli();
                node->handler(irq, node->dev_id, fp);
                restore_flags(flags);

                server->count--;
                return;
        }

        /*
         * Disable the interrupt source in question and reenable all
         * other interrupts. No interrupt handler should ever touch
         * the intena flags directly!
         */
        custom.intena = intena;
        save_flags(flags);
#if 0 /* def CPU_M68060_ONLY */
        sti();
#else
        restore_flags((flags & ~0x0700) | (fp->sr & 0x0700));
#endif

        slow_nodes = node;
        for (;;) {
                for (; node; node = node->next)
                        node->handler(irq, node->dev_id, fp);

                if (!server->reentrance) {
                        server->count--;
                        restore_flags(flags);
                        custom.intena = IF_SETCLR | intena;
                        return;
                }

                server->reentrance = 0;
                node = slow_nodes;
        }
}

/*
 * The builtin Amiga hardware interrupt handlers.
 */

static void ami_int1(int irq, void *dev_id, struct pt_regs *fp)
{
        unsigned short ints = custom.intreqr & custom.intenar;

        /* if serial transmit buffer empty, interrupt */
        if (ints & IF_TBE) {
                custom.intreq = IF_TBE;
                amiga_do_irq(IRQ_AMIGA_TBE, fp);
        }

        /* if floppy disk transfer complete, interrupt */
        if (ints & IF_DSKBLK) {
                custom.intreq = IF_DSKBLK;
                amiga_do_irq(IRQ_AMIGA_DSKBLK, fp);
        }

        /* if software interrupt set, interrupt */
        if (ints & IF_SOFT) {
                custom.intreq = IF_SOFT;
                amiga_do_irq(IRQ_AMIGA_SOFT, fp);
        }
}

static void ami_int3(int irq, void *dev_id, struct pt_regs *fp)
{
        unsigned short ints = custom.intreqr & custom.intenar;
        static struct irq_server server = {0, 0};

        /* if a blitter interrupt */
        if (ints & IF_BLIT) {
                custom.intreq = IF_BLIT;
                amiga_do_irq(IRQ_AMIGA_BLIT, fp);
        }

        /* if a copper interrupt */
        if (ints & IF_COPER) {
                custom.intreq = IF_COPER;
                amiga_do_irq(IRQ_AMIGA_COPPER, fp);
        }

        /* if a vertical blank interrupt */
        if (ints & IF_VERTB)
                amiga_do_irq_list(IRQ_AMIGA_VERTB, fp, &server);
}

static void ami_int4(int irq, void *dev_id, struct pt_regs *fp)
{
        unsigned short ints = custom.intreqr & custom.intenar;

        /* if audio 0 interrupt */
        if (ints & IF_AUD0) {
                custom.intreq = IF_AUD0;
                amiga_do_irq(IRQ_AMIGA_AUD0, fp);
        }

        /* if audio 1 interrupt */
        if (ints & IF_AUD1) {
                custom.intreq = IF_AUD1;
                amiga_do_irq(IRQ_AMIGA_AUD1, fp);
        }

        /* if audio 2 interrupt */
        if (ints & IF_AUD2) {
                custom.intreq = IF_AUD2;
                amiga_do_irq(IRQ_AMIGA_AUD2, fp);
        }

        /* if audio 3 interrupt */
        if (ints & IF_AUD3) {
                custom.intreq = IF_AUD3;
                amiga_do_irq(IRQ_AMIGA_AUD3, fp);
        }
}

static void ami_int5(int irq, void *dev_id, struct pt_regs *fp)
{
        unsigned short ints = custom.intreqr & custom.intenar;

        /* if serial receive buffer full interrupt */
        if (ints & IF_RBF) {
                /* acknowledge of IF_RBF must be done by the serial interrupt */
                amiga_do_irq(IRQ_AMIGA_RBF, fp);
        }

        /* if a disk sync interrupt */
        if (ints & IF_DSKSYN) {
                custom.intreq = IF_DSKSYN;
                amiga_do_irq(IRQ_AMIGA_DSKSYN, fp);
        }
}

static void ami_int7(int irq, void *dev_id, struct pt_regs *fp)
{
        panic ("level 7 interrupt received\n");
}

void (*amiga_default_handler[SYS_IRQS])(int, void *, struct pt_regs *) = {
        ami_badint, ami_int1, ami_badint, ami_int3,
        ami_int4, ami_int5, ami_badint, ami_int7
};

int amiga_get_irq_list(char *buf)
{
        int i, len = 0;
        irq_node_t *node;

        for (i = 0; i < AMI_STD_IRQS; i++) {
                if (!(node = ami_irq_list[i]))
                        continue;
                len += sprintf(buf+len, "ami  %2d: %10u ", i,
                               kstat.irqs[0][SYS_IRQS + i]);
                do {
                        if (node->flags & SA_INTERRUPT)
                                len += sprintf(buf+len, "F ");
                        else
                                len += sprintf(buf+len, "  ");
                        len += sprintf(buf+len, "%s\n", node->devname);
                        if ((node = node->next))
                                len += sprintf(buf+len, "                    ");
                } while (node);
        }

        len += cia_get_irq_list(&ciaa_base, buf+len);
        len += cia_get_irq_list(&ciab_base, buf+len);
        return len;
}