Archipelago » qemu

/*

 * ARM MPCore internal peripheral emulation (common code).

 *

 * Copyright (c) 2006-2007 CodeSourcery.

 * Written by Paul Brook

 *

 * This code is licenced under the GPL.

 */

#include "sysbus.h"

#include "qemu-timer.h"

#define NCPU 4

static inline int

gic_get_current_cpu(void)

{

  return cpu_single_env->cpu_index;

}

#include "arm_gic.c"

/* MPCore private memory region.  */

typedef struct {

    uint32_t count;

    uint32_t load;

    uint32_t control;

    uint32_t status;

    uint32_t old_status;

    int64_t tick;

    QEMUTimer *timer;

    struct mpcore_priv_state *mpcore;

    int id; /* Encodes both timer/watchdog and CPU.  */

} mpcore_timer_state;

typedef struct mpcore_priv_state {

    gic_state gic;

    uint32_t scu_control;

    int iomemtype;

    mpcore_timer_state timer[8];

    uint32_t num_cpu;

} mpcore_priv_state;

/* Per-CPU Timers.  */

static inline void mpcore_timer_update_irq(mpcore_timer_state *s)

{

    if (s->status & ~s->old_status) {

        gic_set_pending_private(&s->mpcore->gic, s->id >> 1, 29 + (s->id & 1));

    }

    s->old_status = s->status;

}

/* Return conversion factor from mpcore timer ticks to qemu timer ticks.  */

static inline uint32_t mpcore_timer_scale(mpcore_timer_state *s)

{

    return (((s->control >> 8) & 0xff) + 1) * 10;

}

static void mpcore_timer_reload(mpcore_timer_state *s, int restart)

{

    if (s->count == 0)

        return;

    if (restart)

        s->tick = qemu_get_clock(vm_clock);

    s->tick += (int64_t)s->count * mpcore_timer_scale(s);

    qemu_mod_timer(s->timer, s->tick);

}

static void mpcore_timer_tick(void *opaque)

{

    mpcore_timer_state *s = (mpcore_timer_state *)opaque;

    s->status = 1;

    if (s->control & 2) {

        s->count = s->load;

        mpcore_timer_reload(s, 0);

    } else {

        s->count = 0;

    }

    mpcore_timer_update_irq(s);

}

static uint32_t mpcore_timer_read(mpcore_timer_state *s, int offset)

{

    int64_t val;

    switch (offset) {

    case 0: /* Load */

        return s->load;

        /* Fall through.  */

    case 4: /* Counter.  */

        if (((s->control & 1) == 0) || (s->count == 0))

            return 0;

        /* Slow and ugly, but hopefully won't happen too often.  */

        val = s->tick - qemu_get_clock(vm_clock);

        val /= mpcore_timer_scale(s);

        if (val < 0)

            val = 0;

        return val;

    case 8: /* Control.  */

        return s->control;

    case 12: /* Interrupt status.  */

        return s->status;

    default:

        return 0;

    }

}

static void mpcore_timer_write(mpcore_timer_state *s, int offset,

                               uint32_t value)

{

    int64_t old;

    switch (offset) {

    case 0: /* Load */

        s->load = value;

        /* Fall through.  */

    case 4: /* Counter.  */

        if ((s->control & 1) && s->count) {

            /* Cancel the previous timer.  */

            qemu_del_timer(s->timer);

        }

        s->count = value;

        if (s->control & 1) {

            mpcore_timer_reload(s, 1);

        }

        break;

    case 8: /* Control.  */

        old = s->control;

        s->control = value;

        if (((old & 1) == 0) && (value & 1)) {

            if (s->count == 0 && (s->control & 2))

                s->count = s->load;

            mpcore_timer_reload(s, 1);

        }

        break;

    case 12: /* Interrupt status.  */

        s->status &= ~value;

        mpcore_timer_update_irq(s);

        break;

    }

}

static void mpcore_timer_init(mpcore_priv_state *mpcore,

                              mpcore_timer_state *s, int id)

{

    s->id = id;

    s->mpcore = mpcore;

    s->timer = qemu_new_timer(vm_clock, mpcore_timer_tick, s);

}

/* Per-CPU private memory mapped IO.  */

static uint32_t mpcore_priv_read(void *opaque, target_phys_addr_t offset)

{

    mpcore_priv_state *s = (mpcore_priv_state *)opaque;

    int id;

    offset &= 0xfff;

    if (offset < 0x100) {

        /* SCU */

        switch (offset) {

        case 0x00: /* Control.  */

            return s->scu_control;

        case 0x04: /* Configuration.  */

            id = ((1 << s->num_cpu) - 1) << 4;

            return id | (s->num_cpu - 1);

        case 0x08: /* CPU status.  */

            return 0;

        case 0x0c: /* Invalidate all.  */

            return 0;

        default:

            goto bad_reg;

        }

    } else if (offset < 0x600) {

        /* Interrupt controller.  */

        if (offset < 0x200) {

            id = gic_get_current_cpu();

        } else {

            id = (offset - 0x200) >> 8;

            if (id >= s->num_cpu) {

                return 0;

            }

        }

        return gic_cpu_read(&s->gic, id, offset & 0xff);

    } else if (offset < 0xb00) {

        /* Timers.  */

        if (offset < 0x700) {

            id = gic_get_current_cpu();

        } else {

            id = (offset - 0x700) >> 8;

            if (id >= s->num_cpu) {

                return 0;

            }

        }

        id <<= 1;

        if (offset & 0x20)

          id++;

        return mpcore_timer_read(&s->timer[id], offset & 0xf);

    }

bad_reg:

    hw_error("mpcore_priv_read: Bad offset %x\n", (int)offset);

    return 0;

}

static void mpcore_priv_write(void *opaque, target_phys_addr_t offset,

                          uint32_t value)

{

    mpcore_priv_state *s = (mpcore_priv_state *)opaque;

    int id;

    offset &= 0xfff;

    if (offset < 0x100) {

        /* SCU */

        switch (offset) {

        case 0: /* Control register.  */

            s->scu_control = value & 1;

            break;

        case 0x0c: /* Invalidate all.  */

            /* This is a no-op as cache is not emulated.  */

            break;

        default:

            goto bad_reg;

        }

    } else if (offset < 0x600) {

        /* Interrupt controller.  */

        if (offset < 0x200) {

            id = gic_get_current_cpu();

        } else {

            id = (offset - 0x200) >> 8;

        }

        if (id < s->num_cpu) {

            gic_cpu_write(&s->gic, id, offset & 0xff, value);

        }

    } else if (offset < 0xb00) {

        /* Timers.  */

        if (offset < 0x700) {

            id = gic_get_current_cpu();

        } else {

            id = (offset - 0x700) >> 8;

        }

        if (id < s->num_cpu) {

            id <<= 1;

            if (offset & 0x20)

              id++;

            mpcore_timer_write(&s->timer[id], offset & 0xf, value);

        }

        return;

    }

    return;

bad_reg:

    hw_error("mpcore_priv_read: Bad offset %x\n", (int)offset);

}

static CPUReadMemoryFunc * const mpcore_priv_readfn[] = {

   mpcore_priv_read,

   mpcore_priv_read,

   mpcore_priv_read

};

static CPUWriteMemoryFunc * const mpcore_priv_writefn[] = {

   mpcore_priv_write,

   mpcore_priv_write,

   mpcore_priv_write

};

static void mpcore_priv_map(SysBusDevice *dev, target_phys_addr_t base)

{

    mpcore_priv_state *s = FROM_SYSBUSGIC(mpcore_priv_state, dev);

    cpu_register_physical_memory(base, 0x1000, s->iomemtype);

    cpu_register_physical_memory(base + 0x1000, 0x1000, s->gic.iomemtype);

}

static int mpcore_priv_init(SysBusDevice *dev)

{

    mpcore_priv_state *s = FROM_SYSBUSGIC(mpcore_priv_state, dev);

    int i;

    gic_init(&s->gic, s->num_cpu);

    s->iomemtype = cpu_register_io_memory(mpcore_priv_readfn,

                                          mpcore_priv_writefn, s,

                                          DEVICE_NATIVE_ENDIAN);

    sysbus_init_mmio_cb(dev, 0x2000, mpcore_priv_map);

    for (i = 0; i < s->num_cpu * 2; i++) {

        mpcore_timer_init(s, &s->timer[i], i);

    }

    return 0;

}