/*
* ARM Nested Vectored Interrupt Controller
*
* Copyright (c) 2006-2007 CodeSourcery.
* Written by Paul Brook
*
* This code is licensed under the GPL.
*
* The ARMv7M System controller is fairly tightly tied in with the
* NVIC. Much of that is also implemented here.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "cpu.h"
#include "hw/sysbus.h"
#include "qemu/timer.h"
#include "hw/arm/arm.h"
#include "exec/address-spaces.h"
#include "gic_internal.h"
#include "qemu/log.h"
typedef struct {
GICState gic;
ARMCPU *cpu;
struct {
uint32_t control;
uint32_t reload;
int64_t tick;
QEMUTimer *timer;
} systick;
MemoryRegion sysregmem;
MemoryRegion gic_iomem_alias;
MemoryRegion container;
uint32_t num_irq;
qemu_irq sysresetreq;
} nvic_state;
#define TYPE_NVIC "armv7m_nvic"
/**
* NVICClass:
* @parent_reset: the parent class' reset handler.
*
* A model of the v7M NVIC and System Controller
*/
typedef struct NVICClass {
/*< private >*/
ARMGICClass parent_class;
/*< public >*/
DeviceRealize parent_realize;
void (*parent_reset)(DeviceState *dev);
} NVICClass;
#define NVIC_CLASS(klass) \
OBJECT_CLASS_CHECK(NVICClass, (klass), TYPE_NVIC)
#define NVIC_GET_CLASS(obj) \
OBJECT_GET_CLASS(NVICClass, (obj), TYPE_NVIC)
#define NVIC(obj) \
OBJECT_CHECK(nvic_state, (obj), TYPE_NVIC)
static const uint8_t nvic_id[] = {
0x00, 0xb0, 0x1b, 0x00, 0x0d, 0xe0, 0x05, 0xb1
};
/* qemu timers run at 1GHz. We want something closer to 1MHz. */
#define SYSTICK_SCALE 1000ULL
#define SYSTICK_ENABLE (1 << 0)
#define SYSTICK_TICKINT (1 << 1)
#define SYSTICK_CLKSOURCE (1 << 2)
#define SYSTICK_COUNTFLAG (1 << 16)
int system_clock_scale;
/* Conversion factor from qemu timer to SysTick frequencies. */
static inline int64_t systick_scale(nvic_state *s)
{
if (s->systick.control & SYSTICK_CLKSOURCE)
return system_clock_scale;
else
return 1000;
}
static void systick_reload(nvic_state *s, int reset)
{
/* The Cortex-M3 Devices Generic User Guide says that "When the
* ENABLE bit is set to 1, the counter loads the RELOAD value from the
* SYST RVR register and then counts down". So, we need to check the
* ENABLE bit before reloading the value.
*/
if ((s->systick.control & SYSTICK_ENABLE) == 0) {
return;
}
if (reset)
s->systick.tick = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
s->systick.tick += (s->systick.reload + 1) * systick_scale(s);
timer_mod(s->systick.timer, s->systick.tick);
}
static void systick_timer_tick(void * opaque)
{
nvic_state *s = (nvic_state *)opaque;
s->systick.control |= SYSTICK_COUNTFLAG;
if (s->systick.control & SYSTICK_TICKINT) {
/* Trigger the interrupt. */
armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
}
if (s->systick.reload == 0) {
s->systick.control &= ~SYSTICK_ENABLE;
} else {
systick_reload(s, 0);
}
}
static void systick_reset(nvic_state *s)
{
s->systick.control = 0;
s->systick.reload = 0;
s->systick.tick = 0;
timer_del(s->systick.timer);
}
/* The external routines use the hardware vector numbering, ie. the first
IRQ is #16. The internal GIC routines use #32 as the first IRQ. */
void armv7m_nvic_set_pending(void *opaque, int irq)
{
nvic_state *s = (nvic_state *)opaque;
if (irq >= 16)
irq += 16;
gic_set_pending_private(&s->gic, 0, irq);
}
/* Make pending IRQ active. */
int armv7m_nvic_acknowledge_irq(void *opaque)
{
nvic_state *s = (nvic_state *)opaque;
uint32_t irq;
irq = gic_acknowledge_irq(&s->gic, 0, MEMTXATTRS_UNSPECIFIED);
if (irq == 1023)
hw_error("Interrupt but no vector\n");
if (irq >= 32)
irq -= 16;
return irq;
}
void armv7m_nvic_complete_irq(void *opaque, int irq)
{
nvic_state *s = (nvic_state *)opaque;
if (irq >= 16)
irq += 16;
gic_complete_irq(&s->gic, 0, irq, MEMTXATTRS_UNSPECIFIED);
}
static uint32_t nvic_readl(nvic_state *s, uint32_t offset)
{
ARMCPU *cpu = s->cpu;
uint32_t val;
int irq;
switch (offset) {
case 4: /* Interrupt Control Type. */
return (s->num_irq / 32) - 1;
case 0x10: /* SysTick Control and Status. */
val = s->systick.control;
s->systick.control &= ~SYSTICK_COUNTFLAG;
return val;
case 0x14: /* SysTick Reload Value. */
return s->systick.reload;
case 0x18: /* SysTick Current Value. */
{
int64_t t;
if ((s->systick.control & SYSTICK_ENABLE) == 0)
return 0;
t = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
if (t >= s->systick.tick)
return 0;
val = ((s->systick.tick - (t + 1)) / systick_scale(s)) + 1;
/* The interrupt in triggered when the timer reaches zero.
However the counter is not reloaded until the next clock
tick. This is a hack to return zero during the first tick. */
if (val > s->systick.reload)
val = 0;
return val;
}
case 0x1c: /* SysTick Calibration Value. */
return 10000;
case 0xd00: /* CPUID Base. */
return cpu->midr;
case 0xd04: /* Interrupt Control State. */
/* VECTACTIVE */
val = cpu->env.v7m.exception;
if (val == 1023) {
val = 0;
} else if (val >= 32) {
val -= 16;
}
/* VECTPENDING */
if (s->gic.current_pending[0] != 1023)
val |= (s->gic.current_pending[0] << 12);
/* ISRPENDING and RETTOBASE */
for (irq = 32; irq < s->num_irq; irq++) {
if (s->gic.irq_state[irq].pending) {
val |= (1 << 22);
break;
}
if (irq != cpu->env.v7m.exception && s->gic.irq_state[irq].active) {
val |= (1 << 11);
}
}
/* PENDSTSET */
if (s->gic.irq_state[ARMV7M_EXCP_SYSTICK].pending)
val |= (1 << 26);
/* PENDSVSET */
if (s->gic.irq_state[ARMV7M_EXCP_PENDSV].pending)
val |= (1 << 28);
/* NMIPENDSET */
if (s->gic.irq_state[ARMV7M_EXCP_NMI].pending)
val |= (1 << 31);
return val;
case 0xd08: /* Vector Table Offset. */
return cpu->env.v7m.vecbase;
case 0xd0c: /* Application Interrupt/Reset Control. */
return 0xfa050000;
case 0xd10: /* System Control. */
/* TODO: Implement SLEEPONEXIT. */
return 0;
case 0xd14: /* Configuration Control. */
/* TODO: Implement Configuration Control bits. */
return 0;
case 0xd24: /* System Handler Status. */
val = 0;
if (s->gic.irq_state[ARMV7M_EXCP_MEM].active) val |= (1 << 0);
if (s->gic.irq_state[ARMV7M_EXCP_BUS].active) val |= (1 << 1);
if (s->gic.irq_state[ARMV7M_EXCP_USAGE].active) val |= (1 << 3);
if (s->gic.irq_state[ARMV7M_EXCP_SVC].active) val |= (1 << 7);
if (s->gic.irq_state[ARMV7M_EXCP_DEBUG].active) val |= (1 << 8);
if (s->gic.irq_state[ARMV7M_EXCP_PENDSV].active) val |= (1 << 10);
if (s->gic.irq_state[ARMV7M_EXCP_SYSTICK].active) val |= (1 << 11);
if (s->gic.irq_state[ARMV7M_EXCP_USAGE].pending) val |= (1 << 12);
if (s->gic.irq_state[ARMV7M_EXCP_MEM].pending) val |= (1 << 13);
if (s->gic.irq_state[ARMV7M_EXCP_BUS].pending) val |= (1 << 14);
if (s->gic.irq_state[ARMV7M_EXCP_SVC].pending) val |= (1 << 15);
if (s->gic.irq_state[ARMV7M_EXCP_MEM].enabled) val |= (1 << 16);
if (s->gic.irq_state[ARMV7M_EXCP_BUS].enabled) val |= (1 << 17);
if (s->gic.irq_state[ARMV7M_EXCP_USAGE].enabled) val |= (1 << 18);
return val;
case 0xd28: /* Configurable Fault Status. */
/* TODO: Implement Fault Status. */
qemu_log_mask(LOG_UNIMP, "Configurable Fault Status unimplemented\n");
return 0;
case 0xd2c: /* Hard Fault Status. */
case 0xd30: /* Debug Fault Status. */
case 0xd34: /* Mem Manage Address. */
case 0xd38: /* Bus Fault Address. */
case 0xd3c: /* Aux Fault Status. */
/* TODO: Implement fault status registers. */
qemu_log_mask(LOG_UNIMP, "Fault status registers unimplemented\n");
return 0;
case 0xd40: /* PFR0. */
return 0x00000030;
case 0xd44: /* PRF1. */
return 0x00000200;
case 0xd48: /* DFR0. */
return 0x00100000;
case 0xd4c: /* AFR0. */
return 0x00000000;
case 0xd50: /* MMFR0. */
return 0x00000030;
case 0xd54: /* MMFR1. */
return 0x00000000;
case 0xd58: /* MMFR2. */
return 0x00000000;
case 0xd5c: /* MMFR3. */
return 0x00000000;
case 0xd60: /* ISAR0. */
return 0x01141110;
case 0xd64: /* ISAR1. */
return 0x02111000;
case 0xd68: /* ISAR2. */
return 0x21112231;
case 0xd6c: /* ISAR3. */
return 0x01111110;
case 0xd70: /* ISAR4. */
return 0x01310102;
/* TODO: Implement debug registers. */
default:
qemu_log_mask(LOG_GUEST_ERROR, "NVIC: Bad read offset 0x%x\n", offset);
return 0;
}
}
static void nvic_writel(nvic_state *s, uint32_t offset, uint32_t value)
{
ARMCPU *cpu = s->cpu;
uint32_t oldval;
switch (offset) {
case 0x10: /* SysTick Control and Status. */
oldval = s->systick.control;
s->systick.control &= 0xfffffff8;
s->systick.control |= value & 7;
if ((oldval ^ value) & SYSTICK_ENABLE) {
int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
if (value & SYSTICK_ENABLE) {
if (s->systick.tick) {
s->systick.tick += now;
timer_mod(s->systick.timer, s->systick.tick);
} else {
systick_reload(s, 1);
}
} else {
timer_del(s->systick.timer);
s->systick.tick -= now;
if (s->systick.tick < 0)
s->systick.tick = 0;
}
} else if ((oldval ^ value) & SYSTICK_CLKSOURCE) {
/* This is a hack. Force the timer to be reloaded
when the reference clock is changed. */
systick_reload(s, 1);
}
break;
case 0x14: /* SysTick Reload Value. */
s->systick.reload = value;
break;
case 0x18: /* SysTick Current Value. Writes reload the timer. */
systick_reload(s, 1);
s->systick.control &= ~SYSTICK_COUNTFLAG;
break;
case 0xd04: /* Interrupt Control State. */
if (value & (1 << 31)) {
armv7m_nvic_set_pending(s, ARMV7M_EXCP_NMI);
}
if (value & (1 << 28)) {
armv7m_nvic_set_pending(s, ARMV7M_EXCP_PENDSV);
} else if (value & (1 << 27)) {
s->gic.irq_state[ARMV7M_EXCP_PENDSV].pending = 0;
gic_update(&s->gic);
}
if (value & (1 << 26)) {
armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK);
} else if (value & (1 << 25)) {
s->gic.irq_state[ARMV7M_EXCP_SYSTICK].pending = 0;
gic_update(&s->gic);
}
break;
case 0xd08: /* Vector Table Offset. */
cpu->env.v7m.vecbase = value & 0xffffff80;
break;
case 0xd0c: /* Application Interrupt/Reset Control. */
if ((value >> 16) == 0x05fa) {
if (value & 4) {
qemu_irq_pulse(s->sysresetreq);
}
if (value & 2) {
qemu_log_mask(LOG_UNIMP, "VECTCLRACTIVE unimplemented\n");
}
if (value & 1) {
qemu_log_mask(LOG_UNIMP, "AIRCR system reset unimplemented\n");
}
if (value & 0x700) {
qemu_log_mask(LOG_UNIMP, "PRIGROUP unimplemented\n");
}
}
break;
case 0xd10: /* System Control. */
case 0xd14: /* Configuration Control. */
/* TODO: Implement control registers. */
qemu_log_mask(LOG_UNIMP, "NVIC: SCR and CCR unimplemented\n");
break;
case 0xd24: /* System Handler Control. */
/* TODO: Real hardware allows you to set/clear the active bits
under some circumstances. We don't implement this. */
s->gic.irq_state[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0;
s->gic.irq_state[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0;
s->gic.irq_state[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0;
break;
case 0xd28: /* Configurable Fault Status. */
case 0xd2c: /* Hard Fault Status. */
case 0xd30: /* Debug Fault Status. */
case 0xd34: /* Mem Manage Address. */
case 0xd38: /* Bus Fault Address. */
case 0xd3c: /* Aux Fault Status. */
qemu_log_mask(LOG_UNIMP,
"NVIC: fault status registers unimplemented\n");
break;
case 0xf00: /* Software Triggered Interrupt Register */
if ((value & 0x1ff) < s->num_irq) {
gic_set_pending_private(&s->gic, 0, value & 0x1ff);
}
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"NVIC: Bad write offset 0x%x\n", offset);
}
}
static uint64_t nvic_sysreg_read(void *opaque, hwaddr addr,
unsigned size)
{
nvic_state *s = (nvic_state *)opaque;
uint32_t offset = addr;
int i;
uint32_t val;
switch (offset) {
case 0xd18 ... 0xd23: /* System Handler Priority. */
val = 0;
for (i = 0; i < size; i++) {
val |= s->gic.priority1[(offset - 0xd14) + i][0] << (i * 8);
}
return val;
case 0xfe0 ... 0xfff: /* ID. */
if (offset & 3) {
return 0;
}
return nvic_id[(offset - 0xfe0) >> 2];
}
if (size == 4) {
return nvic_readl(s, offset);
}
qemu_log_mask(LOG_GUEST_ERROR,
"NVIC: Bad read of size %d at offset 0x%x\n", size, offset);
return 0;
}
static void nvic_sysreg_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
nvic_state *s = (nvic_state *)opaque;
uint32_t offset = addr;
int i;
switch (offset) {
case 0xd18 ... 0xd23: /* System Handler Priority. */
for (i = 0; i < size; i++) {
s->gic.priority1[(offset - 0xd14) + i][0] =
(value >> (i * 8)) & 0xff;
}
gic_update(&s->gic);
return;
}
if (size == 4) {
nvic_writel(s, offset, value);
return;
}
qemu_log_mask(LOG_GUEST_ERROR,
"NVIC: Bad write of size %d at offset 0x%x\n", size, offset);
}
static const MemoryRegionOps nvic_sysreg_ops = {
.read = nvic_sysreg_read,
.write = nvic_sysreg_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static const VMStateDescription vmstate_nvic = {
.name = "armv7m_nvic",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32(systick.control, nvic_state),
VMSTATE_UINT32(systick.reload, nvic_state),
VMSTATE_INT64(systick.tick, nvic_state),
VMSTATE_TIMER_PTR(systick.timer, nvic_state),
VMSTATE_END_OF_LIST()
}
};
static void armv7m_nvic_reset(DeviceState *dev)
{
nvic_state *s = NVIC(dev);
NVICClass *nc = NVIC_GET_CLASS(s);
nc->parent_reset(dev);
/* Common GIC reset resets to disabled; the NVIC doesn't have
* per-CPU interfaces so mark our non-existent CPU interface
* as enabled by default, and with a priority mask which allows
* all interrupts through.
*/
s->gic.cpu_ctlr[0] = GICC_CTLR_EN_GRP0;
s->gic.priority_mask[0] = 0x100;
/* The NVIC as a whole is always enabled. */
s->gic.ctlr = 1;
systick_reset(s);
}
static void armv7m_nvic_realize(DeviceState *dev, Error **errp)
{
nvic_state *s = NVIC(dev);
NVICClass *nc = NVIC_GET_CLASS(s);
Error *local_err = NULL;
s->cpu = ARM_CPU(qemu_get_cpu(0));
assert(s->cpu);
/* The NVIC always has only one CPU */
s->gic.num_cpu = 1;
/* Tell the common code we're an NVIC */
s->gic.revision = 0xffffffff;
s->num_irq = s->gic.num_irq;
nc->parent_realize(dev, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
gic_init_irqs_and_distributor(&s->gic);
/* The NVIC and system controller register area looks like this:
* 0..0xff : system control registers, including systick
* 0x100..0xcff : GIC-like registers
* 0xd00..0xfff : system control registers
* We use overlaying to put the GIC like registers
* over the top of the system control register region.
*/
memory_region_init(&s->container, OBJECT(s), "nvic", 0x1000);
/* The system register region goes at the bottom of the priority
* stack as it covers the whole page.
*/
memory_region_init_io(&s->sysregmem, OBJECT(s), &nvic_sysreg_ops, s,
"nvic_sysregs", 0x1000);
memory_region_add_subregion(&s->container, 0, &s->sysregmem);
/* Alias the GIC region so we can get only the section of it
* we need, and layer it on top of the system register region.
*/
memory_region_init_alias(&s->gic_iomem_alias, OBJECT(s),
"nvic-gic", &s->gic.iomem,
0x100, 0xc00);
memory_region_add_subregion_overlap(&s->container, 0x100,
&s->gic_iomem_alias, 1);
/* Map the whole thing into system memory at the location required
* by the v7M architecture.
*/
memory_region_add_subregion(get_system_memory(), 0xe000e000, &s->container);
s->systick.timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, systick_timer_tick, s);
}
static void armv7m_nvic_instance_init(Object *obj)
{
/* We have a different default value for the num-irq property
* than our superclass. This function runs after qdev init
* has set the defaults from the Property array and before
* any user-specified property setting, so just modify the
* value in the GICState struct.
*/
GICState *s = ARM_GIC_COMMON(obj);
DeviceState *dev = DEVICE(obj);
nvic_state *nvic = NVIC(obj);
/* The ARM v7m may have anything from 0 to 496 external interrupt
* IRQ lines. We default to 64. Other boards may differ and should
* set the num-irq property appropriately.
*/
s->num_irq = 64;
qdev_init_gpio_out_named(dev, &nvic->sysresetreq, "SYSRESETREQ", 1);
}
static void armv7m_nvic_class_init(ObjectClass *klass, void *data)
{
NVICClass *nc = NVIC_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);
nc->parent_reset = dc->reset;
nc->parent_realize = dc->realize;
dc->vmsd = &vmstate_nvic;
dc->reset = armv7m_nvic_reset;
dc->realize = armv7m_nvic_realize;
}
static const TypeInfo armv7m_nvic_info = {
.name = TYPE_NVIC,
.parent = TYPE_ARM_GIC_COMMON,
.instance_init = armv7m_nvic_instance_init,
.instance_size = sizeof(nvic_state),
.class_init = armv7m_nvic_class_init,
.class_size = sizeof(NVICClass),
};
static void armv7m_nvic_register_types(void)
{
type_register_static(&armv7m_nvic_info);
}
type_init(armv7m_nvic_register_types)
