qemu-e2k/hw/m68k/mcf_intc.c

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/*
* ColdFire Interrupt Controller emulation.
*
* Copyright (c) 2007 CodeSourcery.
*
* This code is licensed under the GPL
*/
#include "hw/hw.h"
#include "hw/m68k/mcf.h"
#include "exec/address-spaces.h"
typedef struct {
MemoryRegion iomem;
uint64_t ipr;
uint64_t imr;
uint64_t ifr;
uint64_t enabled;
uint8_t icr[64];
M68kCPU *cpu;
int active_vector;
} mcf_intc_state;
static void mcf_intc_update(mcf_intc_state *s)
{
uint64_t active;
int i;
int best;
int best_level;
active = (s->ipr | s->ifr) & s->enabled & ~s->imr;
best_level = 0;
best = 64;
if (active) {
for (i = 0; i < 64; i++) {
if ((active & 1) != 0 && s->icr[i] >= best_level) {
best_level = s->icr[i];
best = i;
}
active >>= 1;
}
}
s->active_vector = ((best == 64) ? 24 : (best + 64));
m68k_set_irq_level(s->cpu, best_level, s->active_vector);
}
static uint64_t mcf_intc_read(void *opaque, hwaddr addr,
unsigned size)
{
int offset;
mcf_intc_state *s = (mcf_intc_state *)opaque;
offset = addr & 0xff;
if (offset >= 0x40 && offset < 0x80) {
return s->icr[offset - 0x40];
}
switch (offset) {
case 0x00:
return (uint32_t)(s->ipr >> 32);
case 0x04:
return (uint32_t)s->ipr;
case 0x08:
return (uint32_t)(s->imr >> 32);
case 0x0c:
return (uint32_t)s->imr;
case 0x10:
return (uint32_t)(s->ifr >> 32);
case 0x14:
return (uint32_t)s->ifr;
case 0xe0: /* SWIACK. */
return s->active_vector;
case 0xe1: case 0xe2: case 0xe3: case 0xe4:
case 0xe5: case 0xe6: case 0xe7:
/* LnIACK */
hw_error("mcf_intc_read: LnIACK not implemented\n");
default:
return 0;
}
}
static void mcf_intc_write(void *opaque, hwaddr addr,
uint64_t val, unsigned size)
{
int offset;
mcf_intc_state *s = (mcf_intc_state *)opaque;
offset = addr & 0xff;
if (offset >= 0x40 && offset < 0x80) {
int n = offset - 0x40;
s->icr[n] = val;
if (val == 0)
s->enabled &= ~(1ull << n);
else
s->enabled |= (1ull << n);
mcf_intc_update(s);
return;
}
switch (offset) {
case 0x00: case 0x04:
/* Ignore IPR writes. */
return;
case 0x08:
s->imr = (s->imr & 0xffffffff) | ((uint64_t)val << 32);
break;
case 0x0c:
s->imr = (s->imr & 0xffffffff00000000ull) | (uint32_t)val;
break;
default:
hw_error("mcf_intc_write: Bad write offset %d\n", offset);
break;
}
mcf_intc_update(s);
}
static void mcf_intc_set_irq(void *opaque, int irq, int level)
{
mcf_intc_state *s = (mcf_intc_state *)opaque;
if (irq >= 64)
return;
if (level)
s->ipr |= 1ull << irq;
else
s->ipr &= ~(1ull << irq);
mcf_intc_update(s);
}
static void mcf_intc_reset(mcf_intc_state *s)
{
s->imr = ~0ull;
s->ipr = 0;
s->ifr = 0;
s->enabled = 0;
memset(s->icr, 0, 64);
s->active_vector = 24;
}
static const MemoryRegionOps mcf_intc_ops = {
.read = mcf_intc_read,
.write = mcf_intc_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
qemu_irq *mcf_intc_init(MemoryRegion *sysmem,
hwaddr base,
M68kCPU *cpu)
{
mcf_intc_state *s;
s = g_malloc0(sizeof(mcf_intc_state));
s->cpu = cpu;
mcf_intc_reset(s);
memory_region_init_io(&s->iomem, NULL, &mcf_intc_ops, s, "mcf", 0x100);
memory_region_add_subregion(sysmem, base, &s->iomem);
return qemu_allocate_irqs(mcf_intc_set_irq, s, 64);
}