qemu-e2k/hw/arm_gic.c

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/*
* ARM AMBA Generic/Distributed Interrupt Controller
*
* Copyright (c) 2006 CodeSourcery.
* Written by Paul Brook
*
* This code is licenced under the GPL.
*/
/* TODO: Some variants of this controller can handle multiple CPUs.
Currently only single CPU operation is implemented. */
#include "vl.h"
#include "arm_pic.h"
//#define DEBUG_GIC
#ifdef DEBUG_GIC
#define DPRINTF(fmt, args...) \
do { printf("arm_gic: " fmt , ##args); } while (0)
#else
#define DPRINTF(fmt, args...) do {} while(0)
#endif
/* Distributed interrupt controller. */
static const uint8_t gic_id[] =
{ 0x90, 0x13, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
#define GIC_NIRQ 96
typedef struct gic_irq_state
{
unsigned enabled:1;
unsigned pending:1;
unsigned active:1;
unsigned level:1;
unsigned model:1; /* 0 = 1:N, 1 = N:N */
unsigned trigger:1; /* nonzero = edge triggered. */
} gic_irq_state;
#define GIC_SET_ENABLED(irq) s->irq_state[irq].enabled = 1
#define GIC_CLEAR_ENABLED(irq) s->irq_state[irq].enabled = 0
#define GIC_TEST_ENABLED(irq) s->irq_state[irq].enabled
#define GIC_SET_PENDING(irq) s->irq_state[irq].pending = 1
#define GIC_CLEAR_PENDING(irq) s->irq_state[irq].pending = 0
#define GIC_TEST_PENDING(irq) s->irq_state[irq].pending
#define GIC_SET_ACTIVE(irq) s->irq_state[irq].active = 1
#define GIC_CLEAR_ACTIVE(irq) s->irq_state[irq].active = 0
#define GIC_TEST_ACTIVE(irq) s->irq_state[irq].active
#define GIC_SET_MODEL(irq) s->irq_state[irq].model = 1
#define GIC_CLEAR_MODEL(irq) s->irq_state[irq].model = 0
#define GIC_TEST_MODEL(irq) s->irq_state[irq].model
#define GIC_SET_LEVEL(irq) s->irq_state[irq].level = 1
#define GIC_CLEAR_LEVEL(irq) s->irq_state[irq].level = 0
#define GIC_TEST_LEVEL(irq) s->irq_state[irq].level
#define GIC_SET_TRIGGER(irq) s->irq_state[irq].trigger = 1
#define GIC_CLEAR_TRIGGER(irq) s->irq_state[irq].trigger = 0
#define GIC_TEST_TRIGGER(irq) s->irq_state[irq].trigger
typedef struct gic_state
{
uint32_t base;
qemu_irq parent_irq;
int enabled;
int cpu_enabled;
gic_irq_state irq_state[GIC_NIRQ];
int irq_target[GIC_NIRQ];
int priority[GIC_NIRQ];
int last_active[GIC_NIRQ];
int priority_mask;
int running_irq;
int running_priority;
int current_pending;
} gic_state;
/* TODO: Many places that call this routine could be optimized. */
/* Update interrupt status after enabled or pending bits have been changed. */
static void gic_update(gic_state *s)
{
int best_irq;
int best_prio;
int irq;
s->current_pending = 1023;
if (!s->enabled || !s->cpu_enabled) {
qemu_irq_lower(s->parent_irq);
return;
}
best_prio = 0x100;
best_irq = 1023;
for (irq = 0; irq < 96; irq++) {
if (GIC_TEST_ENABLED(irq) && GIC_TEST_PENDING(irq)) {
if (s->priority[irq] < best_prio) {
best_prio = s->priority[irq];
best_irq = irq;
}
}
}
if (best_prio > s->priority_mask) {
qemu_irq_lower(s->parent_irq);
} else {
s->current_pending = best_irq;
if (best_prio < s->running_priority) {
DPRINTF("Raised pending IRQ %d\n", best_irq);
qemu_irq_raise(s->parent_irq);
}
}
}
static void gic_set_irq(void *opaque, int irq, int level)
{
gic_state *s = (gic_state *)opaque;
/* The first external input line is internal interrupt 32. */
irq += 32;
if (level == GIC_TEST_LEVEL(irq))
return;
if (level) {
GIC_SET_LEVEL(irq);
if (GIC_TEST_TRIGGER(irq) || GIC_TEST_ENABLED(irq)) {
DPRINTF("Set %d pending\n", irq);
GIC_SET_PENDING(irq);
}
} else {
GIC_CLEAR_LEVEL(irq);
}
gic_update(s);
}
static void gic_set_running_irq(gic_state *s, int irq)
{
s->running_irq = irq;
if (irq == 1023)
s->running_priority = 0x100;
else
s->running_priority = s->priority[irq];
gic_update(s);
}
static uint32_t gic_acknowledge_irq(gic_state *s)
{
int new_irq;
new_irq = s->current_pending;
if (new_irq == 1023 || s->priority[new_irq] >= s->running_priority) {
DPRINTF("ACK no pending IRQ\n");
return 1023;
}
qemu_irq_lower(s->parent_irq);
s->last_active[new_irq] = s->running_irq;
/* For level triggered interrupts we clear the pending bit while
the interrupt is active. */
GIC_CLEAR_PENDING(new_irq);
gic_set_running_irq(s, new_irq);
DPRINTF("ACK %d\n", new_irq);
return new_irq;
}
static void gic_complete_irq(gic_state * s, int irq)
{
int update = 0;
DPRINTF("EOI %d\n", irq);
if (s->running_irq == 1023)
return; /* No active IRQ. */
if (irq != 1023) {
/* Mark level triggered interrupts as pending if they are still
raised. */
if (!GIC_TEST_TRIGGER(irq) && GIC_TEST_ENABLED(irq)
&& GIC_TEST_LEVEL(irq)) {
GIC_SET_PENDING(irq);
update = 1;
}
}
if (irq != s->running_irq) {
/* Complete an IRQ that is not currently running. */
int tmp = s->running_irq;
while (s->last_active[tmp] != 1023) {
if (s->last_active[tmp] == irq) {
s->last_active[tmp] = s->last_active[irq];
break;
}
tmp = s->last_active[tmp];
}
if (update) {
gic_update(s);
}
} else {
/* Complete the current running IRQ. */
gic_set_running_irq(s, s->last_active[s->running_irq]);
}
}
static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset)
{
gic_state *s = (gic_state *)opaque;
uint32_t res;
int irq;
int i;
offset -= s->base + 0x1000;
if (offset < 0x100) {
if (offset == 0)
return s->enabled;
if (offset == 4)
return (GIC_NIRQ / 32) - 1;
if (offset < 0x08)
return 0;
goto bad_reg;
} else if (offset < 0x200) {
/* Interrupt Set/Clear Enable. */
if (offset < 0x180)
irq = (offset - 0x100) * 8;
else
irq = (offset - 0x180) * 8;
if (irq >= GIC_NIRQ)
goto bad_reg;
res = 0;
for (i = 0; i < 8; i++) {
if (GIC_TEST_ENABLED(irq + i)) {
res |= (1 << i);
}
}
} else if (offset < 0x300) {
/* Interrupt Set/Clear Pending. */
if (offset < 0x280)
irq = (offset - 0x200) * 8;
else
irq = (offset - 0x280) * 8;
if (irq >= GIC_NIRQ)
goto bad_reg;
res = 0;
for (i = 0; i < 8; i++) {
if (GIC_TEST_PENDING(irq + i)) {
res |= (1 << i);
}
}
} else if (offset < 0x400) {
/* Interrupt Active. */
irq = (offset - 0x300) * 8;
if (irq >= GIC_NIRQ)
goto bad_reg;
res = 0;
for (i = 0; i < 8; i++) {
if (GIC_TEST_ACTIVE(irq + i)) {
res |= (1 << i);
}
}
} else if (offset < 0x800) {
/* Interrupt Priority. */
irq = offset - 0x400;
if (irq >= GIC_NIRQ)
goto bad_reg;
res = s->priority[irq];
} else if (offset < 0xc00) {
/* Interrupt CPU Target. */
irq = offset - 0x800;
if (irq >= GIC_NIRQ)
goto bad_reg;
res = s->irq_target[irq];
} else if (offset < 0xf00) {
/* Interrupt Configuration. */
irq = (offset - 0xc00) * 2;
if (irq >= GIC_NIRQ)
goto bad_reg;
res = 0;
for (i = 0; i < 4; i++) {
if (GIC_TEST_MODEL(irq + i))
res |= (1 << (i * 2));
if (GIC_TEST_TRIGGER(irq + i))
res |= (2 << (i * 2));
}
} else if (offset < 0xfe0) {
goto bad_reg;
} else /* offset >= 0xfe0 */ {
if (offset & 3) {
res = 0;
} else {
res = gic_id[(offset - 0xfe0) >> 2];
}
}
return res;
bad_reg:
cpu_abort (cpu_single_env, "gic_dist_readb: Bad offset %x\n", offset);
return 0;
}
static uint32_t gic_dist_readw(void *opaque, target_phys_addr_t offset)
{
uint32_t val;
val = gic_dist_readb(opaque, offset);
val |= gic_dist_readb(opaque, offset + 1) << 8;
return val;
}
static uint32_t gic_dist_readl(void *opaque, target_phys_addr_t offset)
{
uint32_t val;
val = gic_dist_readw(opaque, offset);
val |= gic_dist_readw(opaque, offset + 2) << 16;
return val;
}
static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
uint32_t value)
{
gic_state *s = (gic_state *)opaque;
int irq;
int i;
offset -= s->base + 0x1000;
if (offset < 0x100) {
if (offset == 0) {
s->enabled = (value & 1);
DPRINTF("Distribution %sabled\n", s->enabled ? "En" : "Dis");
} else if (offset < 4) {
/* ignored. */
} else {
goto bad_reg;
}
} else if (offset < 0x180) {
/* Interrupt Set Enable. */
irq = (offset - 0x100) * 8;
if (irq >= GIC_NIRQ)
goto bad_reg;
for (i = 0; i < 8; i++) {
if (value & (1 << i)) {
if (!GIC_TEST_ENABLED(irq + i))
DPRINTF("Enabled IRQ %d\n", irq + i);
GIC_SET_ENABLED(irq + i);
/* If a raised level triggered IRQ enabled then mark
is as pending. */
if (GIC_TEST_LEVEL(irq + i) && !GIC_TEST_TRIGGER(irq + i))
GIC_SET_PENDING(irq + i);
}
}
} else if (offset < 0x200) {
/* Interrupt Clear Enable. */
irq = (offset - 0x180) * 8;
if (irq >= GIC_NIRQ)
goto bad_reg;
for (i = 0; i < 8; i++) {
if (value & (1 << i)) {
if (GIC_TEST_ENABLED(irq + i))
DPRINTF("Disabled IRQ %d\n", irq + i);
GIC_CLEAR_ENABLED(irq + i);
}
}
} else if (offset < 0x280) {
/* Interrupt Set Pending. */
irq = (offset - 0x200) * 8;
if (irq >= GIC_NIRQ)
goto bad_reg;
for (i = 0; i < 8; i++) {
if (value & (1 << i)) {
GIC_SET_PENDING(irq + i);
}
}
} else if (offset < 0x300) {
/* Interrupt Clear Pending. */
irq = (offset - 0x280) * 8;
if (irq >= GIC_NIRQ)
goto bad_reg;
for (i = 0; i < 8; i++) {
if (value & (1 << i)) {
GIC_CLEAR_PENDING(irq + i);
}
}
} else if (offset < 0x400) {
/* Interrupt Active. */
goto bad_reg;
} else if (offset < 0x800) {
/* Interrupt Priority. */
irq = offset - 0x400;
if (irq >= GIC_NIRQ)
goto bad_reg;
s->priority[irq] = value;
} else if (offset < 0xc00) {
/* Interrupt CPU Target. */
irq = offset - 0x800;
if (irq >= GIC_NIRQ)
goto bad_reg;
s->irq_target[irq] = value;
} else if (offset < 0xf00) {
/* Interrupt Configuration. */
irq = (offset - 0xc00) * 4;
if (irq >= GIC_NIRQ)
goto bad_reg;
for (i = 0; i < 4; i++) {
if (value & (1 << (i * 2))) {
GIC_SET_MODEL(irq + i);
} else {
GIC_CLEAR_MODEL(irq + i);
}
if (value & (2 << (i * 2))) {
GIC_SET_TRIGGER(irq + i);
} else {
GIC_CLEAR_TRIGGER(irq + i);
}
}
} else {
/* 0xf00 is only handled for word writes. */
goto bad_reg;
}
gic_update(s);
return;
bad_reg:
cpu_abort (cpu_single_env, "gic_dist_writeb: Bad offset %x\n", offset);
}
static void gic_dist_writew(void *opaque, target_phys_addr_t offset,
uint32_t value)
{
gic_state *s = (gic_state *)opaque;
if (offset - s->base == 0xf00) {
GIC_SET_PENDING(value & 0x3ff);
gic_update(s);
return;
}
gic_dist_writeb(opaque, offset, value & 0xff);
gic_dist_writeb(opaque, offset + 1, value >> 8);
}
static void gic_dist_writel(void *opaque, target_phys_addr_t offset,
uint32_t value)
{
gic_dist_writew(opaque, offset, value & 0xffff);
gic_dist_writew(opaque, offset + 2, value >> 16);
}
static CPUReadMemoryFunc *gic_dist_readfn[] = {
gic_dist_readb,
gic_dist_readw,
gic_dist_readl
};
static CPUWriteMemoryFunc *gic_dist_writefn[] = {
gic_dist_writeb,
gic_dist_writew,
gic_dist_writel
};
static uint32_t gic_cpu_read(void *opaque, target_phys_addr_t offset)
{
gic_state *s = (gic_state *)opaque;
offset -= s->base;
switch (offset) {
case 0x00: /* Control */
return s->cpu_enabled;
case 0x04: /* Priority mask */
return s->priority_mask;
case 0x08: /* Binary Point */
/* ??? Not implemented. */
return 0;
case 0x0c: /* Acknowledge */
return gic_acknowledge_irq(s);
case 0x14: /* Runing Priority */
return s->running_priority;
case 0x18: /* Highest Pending Interrupt */
return s->current_pending;
default:
cpu_abort (cpu_single_env, "gic_cpu_read: Bad offset %x\n", offset);
return 0;
}
}
static void gic_cpu_write(void *opaque, target_phys_addr_t offset,
uint32_t value)
{
gic_state *s = (gic_state *)opaque;
offset -= s->base;
switch (offset) {
case 0x00: /* Control */
s->cpu_enabled = (value & 1);
DPRINTF("CPU %sabled\n", s->cpu_enabled ? "En" : "Dis");
break;
case 0x04: /* Priority mask */
s->priority_mask = (value & 0x3ff);
break;
case 0x08: /* Binary Point */
/* ??? Not implemented. */
break;
case 0x10: /* End Of Interrupt */
return gic_complete_irq(s, value & 0x3ff);
default:
cpu_abort (cpu_single_env, "gic_cpu_write: Bad offset %x\n", offset);
return;
}
gic_update(s);
}
static CPUReadMemoryFunc *gic_cpu_readfn[] = {
gic_cpu_read,
gic_cpu_read,
gic_cpu_read
};
static CPUWriteMemoryFunc *gic_cpu_writefn[] = {
gic_cpu_write,
gic_cpu_write,
gic_cpu_write
};
static void gic_reset(gic_state *s)
{
int i;
memset(s->irq_state, 0, GIC_NIRQ * sizeof(gic_irq_state));
s->priority_mask = 0xf0;
s->current_pending = 1023;
s->running_irq = 1023;
s->running_priority = 0x100;
for (i = 0; i < 15; i++) {
GIC_SET_ENABLED(i);
GIC_SET_TRIGGER(i);
}
s->enabled = 0;
s->cpu_enabled = 0;
}
qemu_irq *arm_gic_init(uint32_t base, qemu_irq parent_irq)
{
gic_state *s;
qemu_irq *qi;
int iomemtype;
s = (gic_state *)qemu_mallocz(sizeof(gic_state));
if (!s)
return NULL;
qi = qemu_allocate_irqs(gic_set_irq, s, GIC_NIRQ);
s->parent_irq = parent_irq;
if (base != 0xffffffff) {
iomemtype = cpu_register_io_memory(0, gic_cpu_readfn,
gic_cpu_writefn, s);
cpu_register_physical_memory(base, 0x00001000, iomemtype);
iomemtype = cpu_register_io_memory(0, gic_dist_readfn,
gic_dist_writefn, s);
cpu_register_physical_memory(base + 0x1000, 0x00001000, iomemtype);
s->base = base;
} else {
s->base = 0;
}
gic_reset(s);
return qi;
}