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/*

 * Arm PrimeCell PL190 Vector Interrupt Controller

 *

 * Copyright (c) 2006 CodeSourcery.

 * Written by Paul Brook

 *

 * This code is licenced under the GPL.

 */

#include "hw.h"

#include "primecell.h"

#include "arm-misc.h"

/* The number of virtual priority levels.  16 user vectors plus the

   unvectored IRQ.  Chained interrupts would require an additional level

   if implemented.  */

#define PL190_NUM_PRIO 17

typedef struct {

    uint32_t level;

    uint32_t soft_level;

    uint32_t irq_enable;

    uint32_t fiq_select;

    uint32_t default_addr;

    uint8_t vect_control[16];

    uint32_t vect_addr[PL190_NUM_PRIO];

    /* Mask containing interrupts with higher priority than this one.  */

    uint32_t prio_mask[PL190_NUM_PRIO + 1];

    int protected;

    /* Current priority level.  */

    int priority;

    int prev_prio[PL190_NUM_PRIO];

    qemu_irq irq;

    qemu_irq fiq;

} pl190_state;

static const unsigned char pl190_id[] =

{ 0x90, 0x11, 0x04, 0x00, 0x0D, 0xf0, 0x05, 0xb1 };

static inline uint32_t pl190_irq_level(pl190_state *s)

{

    return (s->level | s->soft_level) & s->irq_enable & ~s->fiq_select;

}

/* Update interrupts.  */

static void pl190_update(pl190_state *s)

{

    uint32_t level = pl190_irq_level(s);

    int set;

    set = (level & s->prio_mask[s->priority]) != 0;

    qemu_set_irq(s->irq, set);

    set = ((s->level | s->soft_level) & s->fiq_select) != 0;

    qemu_set_irq(s->fiq, set);

}

static void pl190_set_irq(void *opaque, int irq, int level)

{

    pl190_state *s = (pl190_state *)opaque;

    if (level)

        s->level |= 1u << irq;

    else

        s->level &= ~(1u << irq);

    pl190_update(s);

}

static void pl190_update_vectors(pl190_state *s)

{

    uint32_t mask;

    int i;

    int n;

    mask = 0;

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

      {

        s->prio_mask[i] = mask;

        if (s->vect_control[i] & 0x20)

          {

            n = s->vect_control[i] & 0x1f;

            mask |= 1 << n;

          }

      }

    s->prio_mask[16] = mask;

    pl190_update(s);

}

static uint32_t pl190_read(void *opaque, target_phys_addr_t offset)

{

    pl190_state *s = (pl190_state *)opaque;

    int i;

    if (offset >= 0xfe0 && offset < 0x1000) {

        return pl190_id[(offset - 0xfe0) >> 2];

    }

    if (offset >= 0x100 && offset < 0x140) {

        return s->vect_addr[(offset - 0x100) >> 2];

    }

    if (offset >= 0x200 && offset < 0x240) {

        return s->vect_control[(offset - 0x200) >> 2];

    }

    switch (offset >> 2) {

    case 0: /* IRQSTATUS */

        return pl190_irq_level(s);

    case 1: /* FIQSATUS */

        return (s->level | s->soft_level) & s->fiq_select;

    case 2: /* RAWINTR */

        return s->level | s->soft_level;

    case 3: /* INTSELECT */

        return s->fiq_select;

    case 4: /* INTENABLE */

        return s->irq_enable;

    case 6: /* SOFTINT */

        return s->soft_level;

    case 8: /* PROTECTION */

        return s->protected;

    case 12: /* VECTADDR */

        /* Read vector address at the start of an ISR.  Increases the

           current priority level to that of the current interrupt.  */

        for (i = 0; i < s->priority; i++)

          {

            if ((s->level | s->soft_level) & s->prio_mask[i])

              break;

          }

        /* Reading this value with no pending interrupts is undefined.

           We return the default address.  */

        if (i == PL190_NUM_PRIO)

          return s->vect_addr[16];

        if (i < s->priority)

          {

            s->prev_prio[i] = s->priority;

            s->priority = i;

            pl190_update(s);

          }

        return s->vect_addr[s->priority];

    case 13: /* DEFVECTADDR */

        return s->vect_addr[16];

    default:

        cpu_abort (cpu_single_env, "pl190_read: Bad offset %x\n", (int)offset);

        return 0;

    }

}

static void pl190_write(void *opaque, target_phys_addr_t offset, uint32_t val)

{

    pl190_state *s = (pl190_state *)opaque;

    if (offset >= 0x100 && offset < 0x140) {

        s->vect_addr[(offset - 0x100) >> 2] = val;

        pl190_update_vectors(s);

        return;

    }

    if (offset >= 0x200 && offset < 0x240) {

        s->vect_control[(offset - 0x200) >> 2] = val;

        pl190_update_vectors(s);

        return;

    }

    switch (offset >> 2) {

    case 0: /* SELECT */

        /* This is a readonly register, but linux tries to write to it

           anyway.  Ignore the write.  */

        break;

    case 3: /* INTSELECT */

        s->fiq_select = val;

        break;

    case 4: /* INTENABLE */

        s->irq_enable |= val;

        break;

    case 5: /* INTENCLEAR */

        s->irq_enable &= ~val;

        break;

    case 6: /* SOFTINT */

        s->soft_level |= val;

        break;

    case 7: /* SOFTINTCLEAR */

        s->soft_level &= ~val;

        break;

    case 8: /* PROTECTION */

        /* TODO: Protection (supervisor only access) is not implemented.  */

        s->protected = val & 1;

        break;

    case 12: /* VECTADDR */

        /* Restore the previous priority level.  The value written is

           ignored.  */

        if (s->priority < PL190_NUM_PRIO)

            s->priority = s->prev_prio[s->priority];

        break;

    case 13: /* DEFVECTADDR */

        s->default_addr = val;

        break;

    case 0xc0: /* ITCR */

        if (val)

            cpu_abort(cpu_single_env, "pl190: Test mode not implemented\n");

        break;

    default:

        cpu_abort(cpu_single_env, "pl190_write: Bad offset %x\n", (int)offset);

        return;

    }

    pl190_update(s);

}

static CPUReadMemoryFunc *pl190_readfn[] = {

   pl190_read,

   pl190_read,

   pl190_read

};

static CPUWriteMemoryFunc *pl190_writefn[] = {

   pl190_write,

   pl190_write,

   pl190_write

};

static void pl190_reset(pl190_state *s)

{

  int i;

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

    {

      s->vect_addr[i] = 0;

      s->vect_control[i] = 0;

    }

  s->vect_addr[16] = 0;

  s->prio_mask[17] = 0xffffffff;

  s->priority = PL190_NUM_PRIO;

  pl190_update_vectors(s);

}

qemu_irq *pl190_init(uint32_t base, qemu_irq irq, qemu_irq fiq)

{

    pl190_state *s;

    qemu_irq *qi;

    int iomemtype;

    s = (pl190_state *)qemu_mallocz(sizeof(pl190_state));

    iomemtype = cpu_register_io_memory(0, pl190_readfn,

                                       pl190_writefn, s);

    cpu_register_physical_memory(base, 0x00001000, iomemtype);

    qi = qemu_allocate_irqs(pl190_set_irq, s, 32);

    s->irq = irq;

    s->fiq = fiq;

    pl190_reset(s);

    /* ??? Save/restore.  */

    return qi;

}