/*
* ARM Generic/Distributed Interrupt Controller
*
* Copyright (c) 2006-2007 CodeSourcery.
* Written by Paul Brook
*
* This code is licensed 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.
* It is compiled in two ways:
* (1) as a standalone file to produce a sysbus device which is a GIC
* that can be used on the realview board and as one of the builtin
* private peripherals for the ARM MP CPUs (11MPCore, A9, etc)
* (2) by being directly #included into armv7m_nvic.c to produce the
* armv7m_nvic device.
*/
#include "sysbus.h"
#include "arm_gic_internal.h"
//#define DEBUG_GIC
#ifdef DEBUG_GIC
#define DPRINTF(fmt, ...) \
do { fprintf(stderr, "arm_gic: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) do {} while(0)
#endif
static const uint8_t gic_id[] = {
0x90, 0x13, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1
};
#define NUM_CPU(s) ((s)->num_cpu)
static inline int gic_get_current_cpu(gic_state *s)
{
if (s->num_cpu > 1) {
return cpu_single_env->cpu_index;
}
return 0;
}
/* TODO: Many places that call this routine could be optimized. */
/* Update interrupt status after enabled or pending bits have been changed. */
void gic_update(gic_state *s)
{
int best_irq;
int best_prio;
int irq;
int level;
int cpu;
int cm;
for (cpu = 0; cpu < NUM_CPU(s); 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 < s->num_irq; irq++) {
if (GIC_TEST_ENABLED(irq, cm) && 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);
}
}
void 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)
{
/* Meaning of the 'irq' parameter:
* [0..N-1] : external interrupts
* [N..N+31] : PPI (internal) interrupts for CPU 0
* [N+32..N+63] : PPI (internal interrupts for CPU 1
* ...
*/
gic_state *s = (gic_state *)opaque;
int cm, target;
if (irq < (s->num_irq - GIC_INTERNAL)) {
/* The first external input line is internal interrupt 32. */
cm = ALL_CPU_MASK;
irq += GIC_INTERNAL;
target = GIC_TARGET(irq);
} else {
int cpu;
irq -= (s->num_irq - GIC_INTERNAL);
cpu = irq / GIC_INTERNAL;
irq %= GIC_INTERNAL;
cm = 1 << cpu;
target = cm;
}
if (level == GIC_TEST_LEVEL(irq, cm)) {
return;
}
if (level) {
GIC_SET_LEVEL(irq, cm);
if (GIC_TEST_TRIGGER(irq) || GIC_TEST_ENABLED(irq, cm)) {
DPRINTF("Set %d pending mask %x\n", irq, target);
GIC_SET_PENDING(irq, target);
}
} else {
GIC_CLEAR_LEVEL(irq, cm);
}
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);
}
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;
}
void gic_complete_irq(gic_state *s, int cpu, int irq)
{
int update = 0;
int cm = 1 << cpu;
DPRINTF("EOI %d\n", irq);
if (irq >= s->num_irq) {
/* This handles two cases:
* 1. If software writes the ID of a spurious interrupt [ie 1023]
* to the GICC_EOIR, the GIC ignores that write.
* 2. If software writes the number of a non-existent interrupt
* this must be a subcase of "value written does not match the last
* valid interrupt value read from the Interrupt Acknowledge
* register" and so this is UNPREDICTABLE. We choose to ignore it.
*/
return;
}
if (s->running_irq[cpu] == 1023)
return; /* No active IRQ. */
/* Mark level triggered interrupts as pending if they are still
raised. */
if (!GIC_TEST_TRIGGER(irq) && GIC_TEST_ENABLED(irq, cm)
&& 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(s);
cm = 1 << cpu;
if (offset < 0x100) {
if (offset == 0)
return s->enabled;
if (offset == 4)
return ((s->num_irq / 32) - 1) | ((NUM_CPU(s) - 1) << 5);
if (offset < 0x08)
return 0;
if (offset >= 0x80) {
/* Interrupt Security , RAZ/WI */
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;
irq += GIC_BASE_IRQ;
if (irq >= s->num_irq)
goto bad_reg;
res = 0;
for (i = 0; i < 8; i++) {
if (GIC_TEST_ENABLED(irq + i, cm)) {
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 >= s->num_irq)
goto bad_reg;
res = 0;
mask = (irq < GIC_INTERNAL) ? 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 >= s->num_irq)
goto bad_reg;
res = 0;
mask = (irq < GIC_INTERNAL) ? 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 >= s->num_irq)
goto bad_reg;
res = GIC_GET_PRIORITY(irq, cpu);
} else if (offset < 0xc00) {
/* Interrupt CPU Target. */
if (s->num_cpu == 1 && s->revision != REV_11MPCORE) {
/* For uniprocessor GICs these RAZ/WI */
res = 0;
} else {
irq = (offset - 0x800) + GIC_BASE_IRQ;
if (irq >= s->num_irq) {
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 >= s->num_irq)
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:
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;
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(s);
if (offset < 0x100) {
if (offset == 0) {
s->enabled = (value & 1);
DPRINTF("Distribution %sabled\n", s->enabled ? "En" : "Dis");
} else if (offset < 4) {
/* ignored. */
} else if (offset >= 0x80) {
/* Interrupt Security Registers, RAZ/WI */
} else {
goto bad_reg;
}
} else if (offset < 0x180) {
/* Interrupt Set Enable. */
irq = (offset - 0x100) * 8 + GIC_BASE_IRQ;
if (irq >= s->num_irq)
goto bad_reg;
if (irq < 16)
value = 0xff;
for (i = 0; i < 8; i++) {
if (value & (1 << i)) {
int mask = (irq < GIC_INTERNAL) ? (1 << cpu) : GIC_TARGET(irq);
int cm = (irq < GIC_INTERNAL) ? (1 << cpu) : ALL_CPU_MASK;
if (!GIC_TEST_ENABLED(irq + i, cm)) {
DPRINTF("Enabled IRQ %d\n", irq + i);
}
GIC_SET_ENABLED(irq + i, cm);
/* 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 >= s->num_irq)
goto bad_reg;
if (irq < 16)
value = 0;
for (i = 0; i < 8; i++) {
if (value & (1 << i)) {
int cm = (irq < GIC_INTERNAL) ? (1 << cpu) : ALL_CPU_MASK;
if (GIC_TEST_ENABLED(irq + i, cm)) {
DPRINTF("Disabled IRQ %d\n", irq + i);
}
GIC_CLEAR_ENABLED(irq + i, cm);
}
}
} else if (offset < 0x280) {
/* Interrupt Set Pending. */
irq = (offset - 0x200) * 8 + GIC_BASE_IRQ;
if (irq >= s->num_irq)
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 >= s->num_irq)
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 >= s->num_irq)
goto bad_reg;
if (irq < GIC_INTERNAL) {
s->priority1[irq][cpu] = value;
} else {
s->priority2[irq - GIC_INTERNAL] = value;
}
} else if (offset < 0xc00) {
/* Interrupt CPU Target. RAZ/WI on uniprocessor GICs, with the
* annoying exception of the 11MPCore's GIC.
*/
if (s->num_cpu != 1 || s->revision == REV_11MPCORE) {
irq = (offset - 0x800) + GIC_BASE_IRQ;
if (irq >= s->num_irq) {
goto bad_reg;
}
if (irq < 29) {
value = 0;
} else if (irq < GIC_INTERNAL) {
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 >= s->num_irq)
goto bad_reg;
if (irq < GIC_INTERNAL)
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);
}
}
} 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;
if (offset == 0xf00) {
int cpu;
int irq;
int mask;
cpu = gic_get_current_cpu(s);
irq = value & 0x3ff;
switch ((value >> 24) & 3) {
case 0:
mask = (value >> 16) & ALL_CPU_MASK;
break;
case 1:
mask = ALL_CPU_MASK ^ (1 << cpu);
break;
case 2:
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 const MemoryRegionOps gic_dist_ops = {
.old_mmio = {
.read = { gic_dist_readb, gic_dist_readw, gic_dist_readl, },
.write = { gic_dist_writeb, gic_dist_writew, gic_dist_writel, },
},
.endianness = DEVICE_NATIVE_ENDIAN,
};
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: /* Running 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 %d %sabled\n", cpu, 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);
}
/* Wrappers to read/write the GIC CPU interface for the current CPU */
static uint64_t gic_thiscpu_read(void *opaque, target_phys_addr_t addr,
unsigned size)
{
gic_state *s = (gic_state *)opaque;
return gic_cpu_read(s, gic_get_current_cpu(s), addr);
}
static void gic_thiscpu_write(void *opaque, target_phys_addr_t addr,
uint64_t value, unsigned size)
{
gic_state *s = (gic_state *)opaque;
gic_cpu_write(s, gic_get_current_cpu(s), addr, value);
}
/* Wrappers to read/write the GIC CPU interface for a specific CPU.
* These just decode the opaque pointer into gic_state* + cpu id.
*/
static uint64_t gic_do_cpu_read(void *opaque, target_phys_addr_t addr,
unsigned size)
{
gic_state **backref = (gic_state **)opaque;
gic_state *s = *backref;
int id = (backref - s->backref);
return gic_cpu_read(s, id, addr);
}
static void gic_do_cpu_write(void *opaque, target_phys_addr_t addr,
uint64_t value, unsigned size)
{
gic_state **backref = (gic_state **)opaque;
gic_state *s = *backref;
int id = (backref - s->backref);
gic_cpu_write(s, id, addr, value);
}
static const MemoryRegionOps gic_thiscpu_ops = {
.read = gic_thiscpu_read,
.write = gic_thiscpu_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static const MemoryRegionOps gic_cpu_ops = {
.read = gic_do_cpu_read,
.write = gic_do_cpu_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
void gic_init_irqs_and_distributor(gic_state *s, int num_irq)
{
int i;
i = s->num_irq - GIC_INTERNAL;
/* For the GIC, also expose incoming GPIO lines for PPIs for each CPU.
* GPIO array layout is thus:
* [0..N-1] SPIs
* [N..N+31] PPIs for CPU 0
* [N+32..N+63] PPIs for CPU 1
* ...
*/
if (s->revision != REV_NVIC) {
i += (GIC_INTERNAL * s->num_cpu);
}
qdev_init_gpio_in(&s->busdev.qdev, gic_set_irq, i);
for (i = 0; i < NUM_CPU(s); i++) {
sysbus_init_irq(&s->busdev, &s->parent_irq[i]);
}
memory_region_init_io(&s->iomem, &gic_dist_ops, s, "gic_dist", 0x1000);
}
static int arm_gic_init(SysBusDevice *dev)
{
/* Device instance init function for the GIC sysbus device */
int i;
gic_state *s = FROM_SYSBUS(gic_state, dev);
ARMGICClass *agc = ARM_GIC_GET_CLASS(s);
agc->parent_init(dev);
gic_init_irqs_and_distributor(s, s->num_irq);
/* Memory regions for the CPU interfaces (NVIC doesn't have these):
* a region for "CPU interface for this core", then a region for
* "CPU interface for core 0", "for core 1", ...
* NB that the memory region size of 0x100 applies for the 11MPCore
* and also cores following the GIC v1 spec (ie A9).
* GIC v2 defines a larger memory region (0x1000) so this will need
* to be extended when we implement A15.
*/
memory_region_init_io(&s->cpuiomem[0], &gic_thiscpu_ops, s,
"gic_cpu", 0x100);
for (i = 0; i < NUM_CPU(s); i++) {
s->backref[i] = s;
memory_region_init_io(&s->cpuiomem[i+1], &gic_cpu_ops, &s->backref[i],
"gic_cpu", 0x100);
}
/* Distributor */
sysbus_init_mmio(dev, &s->iomem);
/* cpu interfaces (one for "current cpu" plus one per cpu) */
for (i = 0; i <= NUM_CPU(s); i++) {
sysbus_init_mmio(dev, &s->cpuiomem[i]);
}
return 0;
}
static void arm_gic_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(klass);
ARMGICClass *agc = ARM_GIC_CLASS(klass);
agc->parent_init = sbc->init;
sbc->init = arm_gic_init;
dc->no_user = 1;
}
static TypeInfo arm_gic_info = {
.name = TYPE_ARM_GIC,
.parent = TYPE_ARM_GIC_COMMON,
.instance_size = sizeof(gic_state),
.class_init = arm_gic_class_init,
};
static void arm_gic_register_types(void)
{
type_register_static(&arm_gic_info);
}
type_init(arm_gic_register_types)
