qemu-e2k/hw/intc/armv7m_nvic.c

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/*
* 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 "hw/sysbus.h"
#include "qemu/timer.h"
#include "hw/arm/arm.h"
#include "exec/address-spaces.h"
#include "gic_internal.h"
typedef struct {
GICState gic;
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)
{
armv7m_nvic: systick: Reload the RELOAD value and count down only if ENABLE bit is set Consider the following pseudo code to configure SYSTICK (The recommended programming sequence from "the definitive guide to the arm cortex-m3"): SYSTICK Reload Value Register = 0xffff SYSTICK Current Value Register = 0 SYSTICK Control and Status Register = 0x7 The pseudo code "SYSTICK Current Value Register = 0" leads to invoking systick_reload(). As a consequence, the systick.tick member is updated and the systick timer starts to count down when the ENABLE bit of SYSTICK Control and Status Register is cleared. The worst case is that: during the system initialization, the reset value of the SYSTICK Control and Status Register is 0x00000000. When the code "SYSTICK Current Value Register = 0" is executed, the systick.tick member is accumulated with "(s->systick.reload + 1) * systick_scale(s)". The systick_scale() gets the external_ref_clock scale because the CLKSOURCE bit of the SYSTICK Control and Status Register is cleared. This is the incorrect behavior because of the code "SYSTICK Control and Status Register = 0x7". Actually, we want the processor clock instead of the external reference clock. This incorrect behavior defers the generation of the first interrupt. The patch fixes the above-mentioned issue by setting the systick.tick member and modifying the systick timer only if the ENABLE bit of the SYSTICK Control and Status Register is set. In addition, the Cortex-M3 Devices Generic User Guide mentioned that "When ENABLE is set to 1, the counter loads the RELOAD value from the SYST RVR register and then counts down". This patch adheres to the statement of the user guide. Signed-off-by: Adrian Huang <adrianhuang0701@gmail.com> Reviewed-by: Jim Huang <jserv.tw@gmail.com> [PMM: minor tweak to comment text] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-05-12 12:57:16 +02:00
/* 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;
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. */
cpu = ARM_CPU(current_cpu);
return cpu->midr;
case 0xd04: /* Interrupt Control State. */
/* VECTACTIVE */
cpu = ARM_CPU(current_cpu);
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. */
cpu = ARM_CPU(current_cpu);
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;
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 = ARM_CPU(current_cpu);
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;
/* 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)