/*
* ARM Nested Vectored Interrupt Controller
*
* Copyright (c) 2006-2007 CodeSourcery.
* Written by Paul Brook
*
* This code is licenced under the GPL.
*
* The ARMv7M System controller is fairly tightly tied in with the
* NVIC. Much of that is also implemented here.
*/
#include "sysbus.h"
#include "qemu-timer.h"
#include "arm-misc.h"
/* 32 internal lines (16 used for system exceptions) plus 64 external
interrupt lines. */
#define GIC_NIRQ 96
#define NCPU 1
#define NVIC 1
/* Only a single "CPU" interface is present. */
static inline int
gic_get_current_cpu(void)
{
return 0;
}
static uint32_t nvic_readl(void *opaque, uint32_t offset);
static void nvic_writel(void *opaque, uint32_t offset, uint32_t value);
#include "arm_gic.c"
typedef struct {
gic_state gic;
struct {
uint32_t control;
uint32_t reload;
int64_t tick;
QEMUTimer *timer;
} systick;
} nvic_state;
/* 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)
{
if (reset)
s->systick.tick = qemu_get_clock(vm_clock);
s->systick.tick += (s->systick.reload + 1) * systick_scale(s);
qemu_mod_timer(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);
}
}
/* 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);
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);
}
static uint32_t nvic_readl(void *opaque, uint32_t offset)
{
nvic_state *s = (nvic_state *)opaque;
uint32_t val;
int irq;
switch (offset) {
case 4: /* Interrupt Control Type. */
return (GIC_NIRQ / 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_get_clock(vm_clock);
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_single_env->cp15.c0_cpuid;
case 0xd04: /* Interrypt Control State. */
/* VECTACTIVE */
val = s->gic.running_irq[0];
if (val == 1023) {
val = 0;
} else if (val >= 32) {
val -= 16;
}
/* RETTOBASE */
if (s->gic.running_irq[0] == 1023
|| s->gic.last_active[s->gic.running_irq[0]][0] == 1023) {
val |= (1 << 11);
}
/* VECTPENDING */
if (s->gic.current_pending[0] != 1023)
val |= (s->gic.current_pending[0] << 12);
/* ISRPENDING */
for (irq = 32; irq < GIC_NIRQ; irq++) {
if (s->gic.irq_state[irq].pending) {
val |= (1 << 22);
break;
}
}
/* 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_single_env->v7m.vecbase;
case 0xd0c: /* Application Interrupt/Reset Control. */
return 0xfa05000;
case 0xd10: /* System Control. */
/* TODO: Implement SLEEPONEXIT. */
return 0;
case 0xd14: /* Configuration Control. */
/* TODO: Implement Configuration Control bits. */
return 0;
case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority. */
irq = offset - 0xd14;
val = 0;
val = s->gic.priority1[irq++][0];
val = s->gic.priority1[irq++][0] << 8;
val = s->gic.priority1[irq++][0] << 16;
val = s->gic.priority1[irq][0] << 24;
return val;
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. */
hw_error("Not implemented: Configurable Fault Status.");
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. */
goto bad_reg;
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:
bad_reg:
hw_error("NVIC: Bad read offset 0x%x\n", offset);
}
}
static void nvic_writel(void *opaque, uint32_t offset, uint32_t value)
{
nvic_state *s = (nvic_state *)opaque;
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_get_clock(vm_clock);
if (value & SYSTICK_ENABLE) {
if (s->systick.tick) {
s->systick.tick += now;
qemu_mod_timer(s->systick.timer, s->systick.tick);
} else {
systick_reload(s, 1);
}
} else {
qemu_del_timer(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_single_env->v7m.vecbase = value & 0xffffff80;
break;
case 0xd0c: /* Application Interrupt/Reset Control. */
if ((value >> 16) == 0x05fa) {
if (value & 2) {
hw_error("VECTCLRACTIVE not implemented");
}
if (value & 5) {
hw_error("System reset");
}
}
break;
case 0xd10: /* System Control. */
case 0xd14: /* Configuration Control. */
/* TODO: Implement control registers. */
goto bad_reg;
case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority. */
{
int irq;
irq = offset - 0xd14;
s->gic.priority1[irq++][0] = value & 0xff;
s->gic.priority1[irq++][0] = (value >> 8) & 0xff;
s->gic.priority1[irq++][0] = (value >> 16) & 0xff;
s->gic.priority1[irq][0] = (value >> 24) & 0xff;
gic_update(&s->gic);
}
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. */
goto bad_reg;
default:
bad_reg:
hw_error("NVIC: Bad write offset 0x%x\n", offset);
}
}
static void nvic_save(QEMUFile *f, void *opaque)
{
nvic_state *s = (nvic_state *)opaque;
qemu_put_be32(f, s->systick.control);
qemu_put_be32(f, s->systick.reload);
qemu_put_be64(f, s->systick.tick);
qemu_put_timer(f, s->systick.timer);
}
static int nvic_load(QEMUFile *f, void *opaque, int version_id)
{
nvic_state *s = (nvic_state *)opaque;
if (version_id != 1)
return -EINVAL;
s->systick.control = qemu_get_be32(f);
s->systick.reload = qemu_get_be32(f);
s->systick.tick = qemu_get_be64(f);
qemu_get_timer(f, s->systick.timer);
return 0;
}
static int armv7m_nvic_init(SysBusDevice *dev)
{
nvic_state *s= FROM_SYSBUSGIC(nvic_state, dev);
gic_init(&s->gic);
cpu_register_physical_memory(0xe000e000, 0x1000, s->gic.iomemtype);
s->systick.timer = qemu_new_timer(vm_clock, systick_timer_tick, s);
register_savevm("armv7m_nvic", -1, 1, nvic_save, nvic_load, s);
return 0;
}
static void armv7m_nvic_register_devices(void)
{
sysbus_register_dev("armv7m_nvic", sizeof(nvic_state), armv7m_nvic_init);
}
device_init(armv7m_nvic_register_devices)
