/*
* ARM Generic/Distributed Interrupt Controller
*
* Copyright (c) 2006-2007 CodeSourcery.
* Written by Paul Brook
*
* This code is licenced under the GPL.
*/
/* This file contains implementation code for the RealView EB interrupt
controller, MPCore distributed interrupt controller and ARMv7-M
Nested Vectored Interrupt Controller. */
//#define DEBUG_GIC
#ifdef DEBUG_GIC
#define DPRINTF(fmt, ...) \
do { printf("arm_gic: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) do {} while(0)
#endif
#ifdef NVIC
static const uint8_t gic_id[] =
{ 0x00, 0xb0, 0x1b, 0x00, 0x0d, 0xe0, 0x05, 0xb1 };
/* The NVIC has 16 internal vectors. However these are not exposed
through the normal GIC interface. */
#define GIC_BASE_IRQ 32
#else
static const uint8_t gic_id[] =
{ 0x90, 0x13, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 };
#define GIC_BASE_IRQ 0
#endif
#define FROM_SYSBUSGIC(type, dev) \
DO_UPCAST(type, gic, FROM_SYSBUS(gic_state, dev))
typedef struct gic_irq_state
{
/* ??? The documentation seems to imply the enable bits are global, even
for per-cpu interrupts. This seems strange. */
unsigned enabled:1;
unsigned pending:NCPU;
unsigned active:NCPU;
unsigned level:NCPU;
unsigned model:1; /* 0 = N:N, 1 = 1:N */
unsigned trigger:1; /* nonzero = edge triggered. */
} gic_irq_state;
#define ALL_CPU_MASK ((1 << NCPU) - 1)
#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, cm) s->irq_state[irq].pending |= (cm)
#define GIC_CLEAR_PENDING(irq, cm) s->irq_state[irq].pending &= ~(cm)
#define GIC_TEST_PENDING(irq, cm) ((s->irq_state[irq].pending & (cm)) != 0)
#define GIC_SET_ACTIVE(irq, cm) s->irq_state[irq].active |= (cm)
#define GIC_CLEAR_ACTIVE(irq, cm) s->irq_state[irq].active &= ~(cm)
#define GIC_TEST_ACTIVE(irq, cm) ((s->irq_state[irq].active & (cm)) != 0)
#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, cm) s->irq_state[irq].level = (cm)
#define GIC_CLEAR_LEVEL(irq, cm) s->irq_state[irq].level &= ~(cm)
#define GIC_TEST_LEVEL(irq, cm) ((s->irq_state[irq].level & (cm)) != 0)
#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
#define GIC_GET_PRIORITY(irq, cpu) \
(((irq) < 32) ? s->priority1[irq][cpu] : s->priority2[(irq) - 32])
#ifdef NVIC
#define GIC_TARGET(irq) 1
#else
#define GIC_TARGET(irq) s->irq_target[irq]
#endif
typedef struct gic_state
{
SysBusDevice busdev;
qemu_irq parent_irq[NCPU];
int enabled;
int cpu_enabled[NCPU];
gic_irq_state irq_state[GIC_NIRQ];
#ifndef NVIC
int irq_target[GIC_NIRQ];
#endif
int priority1[32][NCPU];
int priority2[GIC_NIRQ - 32];
int last_active[GIC_NIRQ][NCPU];
int priority_mask[NCPU];
int running_irq[NCPU];
int running_priority[NCPU];
int current_pending[NCPU];
int iomemtype;
} 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;
int level;
int cpu;
int cm;
for (cpu = 0; cpu < NCPU; cpu++) {
cm = 1 << cpu;
s->current_pending[cpu] = 1023;
if (!s->enabled || !s->cpu_enabled[cpu]) {
qemu_irq_lower(s->parent_irq[cpu]);
return;
}
best_prio = 0x100;
best_irq = 1023;
for (irq = 0; irq < GIC_NIRQ; irq++) {
if (GIC_TEST_ENABLED(irq) && GIC_TEST_PENDING(irq, cm)) {
if (GIC_GET_PRIORITY(irq, cpu) < best_prio) {
best_prio = GIC_GET_PRIORITY(irq, cpu);
best_irq = irq;
}
}
}
level = 0;
if (best_prio <= s->priority_mask[cpu]) {
s->current_pending[cpu] = best_irq;
if (best_prio < s->running_priority[cpu]) {
DPRINTF("Raised pending IRQ %d\n", best_irq);
level = 1;
}
}
qemu_set_irq(s->parent_irq[cpu], level);
}
}
static void __attribute__((unused))
gic_set_pending_private(gic_state *s, int cpu, int irq)
{
int cm = 1 << cpu;
if (GIC_TEST_PENDING(irq, cm))
return;
DPRINTF("Set %d pending cpu %d\n", irq, cpu);
GIC_SET_PENDING(irq, cm);
gic_update(s);
}
/* Process a change in an external IRQ input. */
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, ALL_CPU_MASK))
return;
if (level) {
GIC_SET_LEVEL(irq, ALL_CPU_MASK);
if (GIC_TEST_TRIGGER(irq) || GIC_TEST_ENABLED(irq)) {
DPRINTF("Set %d pending mask %x\n", irq, GIC_TARGET(irq));
GIC_SET_PENDING(irq, GIC_TARGET(irq));
}
} else {
GIC_CLEAR_LEVEL(irq, ALL_CPU_MASK);
}
gic_update(s);
}
static void gic_set_running_irq(gic_state *s, int cpu, int irq)
{
s->running_irq[cpu] = irq;
if (irq == 1023) {
s->running_priority[cpu] = 0x100;
} else {
s->running_priority[cpu] = GIC_GET_PRIORITY(irq, cpu);
}
gic_update(s);
}
static uint32_t gic_acknowledge_irq(gic_state *s, int cpu)
{
int new_irq;
int cm = 1 << cpu;
new_irq = s->current_pending[cpu];
if (new_irq == 1023
|| GIC_GET_PRIORITY(new_irq, cpu) >= s->running_priority[cpu]) {
DPRINTF("ACK no pending IRQ\n");
return 1023;
}
s->last_active[new_irq][cpu] = s->running_irq[cpu];
/* Clear pending flags for both level and edge triggered interrupts.
Level triggered IRQs will be reasserted once they become inactive. */
GIC_CLEAR_PENDING(new_irq, GIC_TEST_MODEL(new_irq) ? ALL_CPU_MASK : cm);
gic_set_running_irq(s, cpu, new_irq);
DPRINTF("ACK %d\n", new_irq);
return new_irq;
}
static void gic_complete_irq(gic_state * s, int cpu, int irq)
{
int update = 0;
int cm = 1 << cpu;
DPRINTF("EOI %d\n", irq);
if (s->running_irq[cpu] == 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, cm) && (GIC_TARGET(irq) & cm) != 0) {
DPRINTF("Set %d pending mask %x\n", irq, cm);
GIC_SET_PENDING(irq, cm);
update = 1;
}
}
if (irq != s->running_irq[cpu]) {
/* Complete an IRQ that is not currently running. */
int tmp = s->running_irq[cpu];
while (s->last_active[tmp][cpu] != 1023) {
if (s->last_active[tmp][cpu] == irq) {
s->last_active[tmp][cpu] = s->last_active[irq][cpu];
break;
}
tmp = s->last_active[tmp][cpu];
}
if (update) {
gic_update(s);
}
} else {
/* Complete the current running IRQ. */
gic_set_running_irq(s, cpu, s->last_active[s->running_irq[cpu]][cpu]);
}
}
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;
int cpu;
int cm;
int mask;
cpu = gic_get_current_cpu();
cm = 1 << cpu;
if (offset < 0x100) {
#ifndef NVIC
if (offset == 0)
return s->enabled;
if (offset == 4)
return ((GIC_NIRQ / 32) - 1) | ((NCPU - 1) << 5);
if (offset < 0x08)
return 0;
#endif
goto bad_reg;
} else if (offset < 0x200) {
/* Interrupt Set/Clear Enable. */
if (offset < 0x180)
irq = (offset - 0x100) * 8;
else
irq = (offset - 0x180) * 8;
irq += GIC_BASE_IRQ;
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;
irq += GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
res = 0;
mask = (irq < 32) ? cm : ALL_CPU_MASK;
for (i = 0; i < 8; i++) {
if (GIC_TEST_PENDING(irq + i, mask)) {
res |= (1 << i);
}
}
} else if (offset < 0x400) {
/* Interrupt Active. */
irq = (offset - 0x300) * 8 + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
res = 0;
mask = (irq < 32) ? cm : ALL_CPU_MASK;
for (i = 0; i < 8; i++) {
if (GIC_TEST_ACTIVE(irq + i, mask)) {
res |= (1 << i);
}
}
} else if (offset < 0x800) {
/* Interrupt Priority. */
irq = (offset - 0x400) + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
res = GIC_GET_PRIORITY(irq, cpu);
#ifndef NVIC
} else if (offset < 0xc00) {
/* Interrupt CPU Target. */
irq = (offset - 0x800) + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
if (irq >= 29 && irq <= 31) {
res = cm;
} else {
res = GIC_TARGET(irq);
}
} else if (offset < 0xf00) {
/* Interrupt Configuration. */
irq = (offset - 0xc00) * 2 + GIC_BASE_IRQ;
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));
}
#endif
} 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:
hw_error("gic_dist_readb: Bad offset %x\n", (int)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;
#ifdef NVIC
gic_state *s = (gic_state *)opaque;
uint32_t addr;
addr = offset;
if (addr < 0x100 || addr > 0xd00)
return nvic_readl(s, addr);
#endif
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;
int cpu;
cpu = gic_get_current_cpu();
if (offset < 0x100) {
#ifdef NVIC
goto bad_reg;
#else
if (offset == 0) {
s->enabled = (value & 1);
DPRINTF("Distribution %sabled\n", s->enabled ? "En" : "Dis");
} else if (offset < 4) {
/* ignored. */
} else {
goto bad_reg;
}
#endif
} else if (offset < 0x180) {
/* Interrupt Set Enable. */
irq = (offset - 0x100) * 8 + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
if (irq < 16)
value = 0xff;
for (i = 0; i < 8; i++) {
if (value & (1 << i)) {
int mask = (irq < 32) ? (1 << cpu) : GIC_TARGET(irq);
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, mask)
&& !GIC_TEST_TRIGGER(irq + i)) {
DPRINTF("Set %d pending mask %x\n", irq + i, mask);
GIC_SET_PENDING(irq + i, mask);
}
}
}
} else if (offset < 0x200) {
/* Interrupt Clear Enable. */
irq = (offset - 0x180) * 8 + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
if (irq < 16)
value = 0;
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 + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
if (irq < 16)
irq = 0;
for (i = 0; i < 8; i++) {
if (value & (1 << i)) {
GIC_SET_PENDING(irq + i, GIC_TARGET(irq));
}
}
} else if (offset < 0x300) {
/* Interrupt Clear Pending. */
irq = (offset - 0x280) * 8 + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
for (i = 0; i < 8; i++) {
/* ??? This currently clears the pending bit for all CPUs, even
for per-CPU interrupts. It's unclear whether this is the
corect behavior. */
if (value & (1 << i)) {
GIC_CLEAR_PENDING(irq + i, ALL_CPU_MASK);
}
}
} else if (offset < 0x400) {
/* Interrupt Active. */
goto bad_reg;
} else if (offset < 0x800) {
/* Interrupt Priority. */
irq = (offset - 0x400) + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
if (irq < 32) {
s->priority1[irq][cpu] = value;
} else {
s->priority2[irq - 32] = value;
}
#ifndef NVIC
} else if (offset < 0xc00) {
/* Interrupt CPU Target. */
irq = (offset - 0x800) + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
if (irq < 29)
value = 0;
else if (irq < 32)
value = ALL_CPU_MASK;
s->irq_target[irq] = value & ALL_CPU_MASK;
} else if (offset < 0xf00) {
/* Interrupt Configuration. */
irq = (offset - 0xc00) * 4 + GIC_BASE_IRQ;
if (irq >= GIC_NIRQ)
goto bad_reg;
if (irq < 32)
value |= 0xaa;
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);
}
}
#endif
} else {
/* 0xf00 is only handled for 32-bit writes. */
goto bad_reg;
}
gic_update(s);
return;
bad_reg:
hw_error("gic_dist_writeb: Bad offset %x\n", (int)offset);
}
static void gic_dist_writew(void *opaque, target_phys_addr_t offset,
uint32_t value)
{
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_state *s = (gic_state *)opaque;
#ifdef NVIC
uint32_t addr;
addr = offset;
if (addr < 0x100 || (addr > 0xd00 && addr != 0xf00)) {
nvic_writel(s, addr, value);
return;
}
#endif
if (offset == 0xf00) {
int cpu;
int irq;
int mask;
cpu = gic_get_current_cpu();
irq = value & 0x3ff;
switch ((value >> 24) & 3) {
case 0:
mask = (value >> 16) & ALL_CPU_MASK;
break;
case 1:
mask = 1 << cpu;
break;
case 2:
mask = ALL_CPU_MASK ^ (1 << cpu);
break;
default:
DPRINTF("Bad Soft Int target filter\n");
mask = ALL_CPU_MASK;
break;
}
GIC_SET_PENDING(irq, mask);
gic_update(s);
return;
}
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
};
#ifndef NVIC
static uint32_t gic_cpu_read(gic_state *s, int cpu, int offset)
{
switch (offset) {
case 0x00: /* Control */
return s->cpu_enabled[cpu];
case 0x04: /* Priority mask */
return s->priority_mask[cpu];
case 0x08: /* Binary Point */
/* ??? Not implemented. */
return 0;
case 0x0c: /* Acknowledge */
return gic_acknowledge_irq(s, cpu);
case 0x14: /* Runing Priority */
return s->running_priority[cpu];
case 0x18: /* Highest Pending Interrupt */
return s->current_pending[cpu];
default:
hw_error("gic_cpu_read: Bad offset %x\n", (int)offset);
return 0;
}
}
static void gic_cpu_write(gic_state *s, int cpu, int offset, uint32_t value)
{
switch (offset) {
case 0x00: /* Control */
s->cpu_enabled[cpu] = (value & 1);
DPRINTF("CPU %sabled\n", s->cpu_enabled ? "En" : "Dis");
break;
case 0x04: /* Priority mask */
s->priority_mask[cpu] = (value & 0xff);
break;
case 0x08: /* Binary Point */
/* ??? Not implemented. */
break;
case 0x10: /* End Of Interrupt */
return gic_complete_irq(s, cpu, value & 0x3ff);
default:
hw_error("gic_cpu_write: Bad offset %x\n", (int)offset);
return;
}
gic_update(s);
}
#endif
static void gic_reset(gic_state *s)
{
int i;
memset(s->irq_state, 0, GIC_NIRQ * sizeof(gic_irq_state));
for (i = 0 ; i < NCPU; i++) {
s->priority_mask[i] = 0xf0;
s->current_pending[i] = 1023;
s->running_irq[i] = 1023;
s->running_priority[i] = 0x100;
#ifdef NVIC
/* The NVIC doesn't have per-cpu interfaces, so enable by default. */
s->cpu_enabled[i] = 1;
#else
s->cpu_enabled[i] = 0;
#endif
}
for (i = 0; i < 16; i++) {
GIC_SET_ENABLED(i);
GIC_SET_TRIGGER(i);
}
#ifdef NVIC
/* The NVIC is always enabled. */
s->enabled = 1;
#else
s->enabled = 0;
#endif
}
static void gic_save(QEMUFile *f, void *opaque)
{
gic_state *s = (gic_state *)opaque;
int i;
int j;
qemu_put_be32(f, s->enabled);
for (i = 0; i < NCPU; i++) {
qemu_put_be32(f, s->cpu_enabled[i]);
#ifndef NVIC
qemu_put_be32(f, s->irq_target[i]);
#endif
for (j = 0; j < 32; j++)
qemu_put_be32(f, s->priority1[j][i]);
for (j = 0; j < GIC_NIRQ; j++)
qemu_put_be32(f, s->last_active[j][i]);
qemu_put_be32(f, s->priority_mask[i]);
qemu_put_be32(f, s->running_irq[i]);
qemu_put_be32(f, s->running_priority[i]);
qemu_put_be32(f, s->current_pending[i]);
}
for (i = 0; i < GIC_NIRQ - 32; i++) {
qemu_put_be32(f, s->priority2[i]);
}
for (i = 0; i < GIC_NIRQ; i++) {
qemu_put_byte(f, s->irq_state[i].enabled);
qemu_put_byte(f, s->irq_state[i].pending);
qemu_put_byte(f, s->irq_state[i].active);
qemu_put_byte(f, s->irq_state[i].level);
qemu_put_byte(f, s->irq_state[i].model);
qemu_put_byte(f, s->irq_state[i].trigger);
}
}
static int gic_load(QEMUFile *f, void *opaque, int version_id)
{
gic_state *s = (gic_state *)opaque;
int i;
int j;
if (version_id != 1)
return -EINVAL;
s->enabled = qemu_get_be32(f);
for (i = 0; i < NCPU; i++) {
s->cpu_enabled[i] = qemu_get_be32(f);
#ifndef NVIC
s->irq_target[i] = qemu_get_be32(f);
#endif
for (j = 0; j < 32; j++)
s->priority1[j][i] = qemu_get_be32(f);
for (j = 0; j < GIC_NIRQ; j++)
s->last_active[j][i] = qemu_get_be32(f);
s->priority_mask[i] = qemu_get_be32(f);
s->running_irq[i] = qemu_get_be32(f);
s->running_priority[i] = qemu_get_be32(f);
s->current_pending[i] = qemu_get_be32(f);
}
for (i = 0; i < GIC_NIRQ - 32; i++) {
s->priority2[i] = qemu_get_be32(f);
}
for (i = 0; i < GIC_NIRQ; i++) {
s->irq_state[i].enabled = qemu_get_byte(f);
s->irq_state[i].pending = qemu_get_byte(f);
s->irq_state[i].active = qemu_get_byte(f);
s->irq_state[i].level = qemu_get_byte(f);
s->irq_state[i].model = qemu_get_byte(f);
s->irq_state[i].trigger = qemu_get_byte(f);
}
return 0;
}
static void gic_init(gic_state *s)
{
int i;
qdev_init_gpio_in(&s->busdev.qdev, gic_set_irq, GIC_NIRQ - 32);
for (i = 0; i < NCPU; i++) {
sysbus_init_irq(&s->busdev, &s->parent_irq[i]);
}
s->iomemtype = cpu_register_io_memory(gic_dist_readfn,
gic_dist_writefn, s);
gic_reset(s);
register_savevm("arm_gic", -1, 1, gic_save, gic_load, s);
}