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hw/intc/bcm2836_control: Implement local timer

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The BCM2836 control logic module includes a simple
"local timer" which is a programmable down-counter that
can generates an interrupt. Implement this functionality.

Signed-off-by: Zoltán Baldaszti <bztemail@gmail.com>
[PMM: wrote commit message; wrapped long line; tweaked
 some comments to match the final version of the code]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Zoltán Baldaszti 2019-03-15 11:12:28 +00:00 committed by Peter Maydell
parent 7074ab12c8
commit 67d80321f2
2 changed files with 108 additions and 2 deletions
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101
hw/intc/bcm2836_control.c
View File

@ -7,7 +7,9 @@
* This code is licensed under the GNU GPLv2 and later.
*
* At present, only implements interrupt routing, and mailboxes (i.e.,
* not local timer, PMU interrupt, or AXI counters).
* not PMU interrupt, or AXI counters).
*
* ARM Local Timer IRQ Copyright (c) 2019. Zoltán Baldaszti
*
* Ref:
* https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2836/QA7_rev3.4.pdf
@ -18,6 +20,9 @@
#include "qemu/log.h"
#define REG_GPU_ROUTE 0x0c
#define REG_LOCALTIMERROUTING 0x24
#define REG_LOCALTIMERCONTROL 0x34
#define REG_LOCALTIMERACK 0x38
#define REG_TIMERCONTROL 0x40
#define REG_MBOXCONTROL 0x50
#define REG_IRQSRC 0x60
@ -43,6 +48,13 @@
#define IRQ_TIMER 11
#define IRQ_MAX IRQ_TIMER
#define LOCALTIMER_FREQ 38400000
#define LOCALTIMER_INTFLAG (1 << 31)
#define LOCALTIMER_RELOAD (1 << 30)
#define LOCALTIMER_INTENABLE (1 << 29)
#define LOCALTIMER_ENABLE (1 << 28)
#define LOCALTIMER_VALUE(x) ((x) & 0xfffffff)
static void deliver_local(BCM2836ControlState *s, uint8_t core, uint8_t irq,
uint32_t controlreg, uint8_t controlidx)
{
@ -78,6 +90,20 @@ static void bcm2836_control_update(BCM2836ControlState *s)
s->fiqsrc[s->route_gpu_fiq] |= (uint32_t)1 << IRQ_GPU;
}
/*
* handle the control module 'local timer' interrupt for one of the
* cores' IRQ/FIQ; this is distinct from the per-CPU timer
* interrupts handled below.
*/
if ((s->local_timer_control & LOCALTIMER_INTENABLE) &&
(s->local_timer_control & LOCALTIMER_INTFLAG)) {
if (s->route_localtimer & 4) {
s->fiqsrc[(s->route_localtimer & 3)] |= (uint32_t)1 << IRQ_TIMER;
} else {
s->irqsrc[(s->route_localtimer & 3)] |= (uint32_t)1 << IRQ_TIMER;
}
}
for (i = 0; i < BCM2836_NCORES; i++) {
/* handle local timer interrupts for this core */
if (s->timerirqs[i]) {
@ -162,6 +188,54 @@ static void bcm2836_control_set_gpu_fiq(void *opaque, int irq, int level)
bcm2836_control_update(s);
}
static void bcm2836_control_local_timer_set_next(void *opaque)
{
BCM2836ControlState *s = opaque;
uint64_t next_event;
assert(LOCALTIMER_VALUE(s->local_timer_control) > 0);
next_event = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
muldiv64(LOCALTIMER_VALUE(s->local_timer_control),
NANOSECONDS_PER_SECOND, LOCALTIMER_FREQ);
timer_mod(&s->timer, next_event);
}
static void bcm2836_control_local_timer_tick(void *opaque)
{
BCM2836ControlState *s = opaque;
bcm2836_control_local_timer_set_next(s);
s->local_timer_control |= LOCALTIMER_INTFLAG;
bcm2836_control_update(s);
}
static void bcm2836_control_local_timer_control(void *opaque, uint32_t val)
{
BCM2836ControlState *s = opaque;
s->local_timer_control = val;
if (val & LOCALTIMER_ENABLE) {
bcm2836_control_local_timer_set_next(s);
} else {
timer_del(&s->timer);
}
}
static void bcm2836_control_local_timer_ack(void *opaque, uint32_t val)
{
BCM2836ControlState *s = opaque;
if (val & LOCALTIMER_INTFLAG) {
s->local_timer_control &= ~LOCALTIMER_INTFLAG;
}
if ((val & LOCALTIMER_RELOAD) &&
(s->local_timer_control & LOCALTIMER_ENABLE)) {
bcm2836_control_local_timer_set_next(s);
}
}
static uint64_t bcm2836_control_read(void *opaque, hwaddr offset, unsigned size)
{
BCM2836ControlState *s = opaque;
@ -170,6 +244,12 @@ static uint64_t bcm2836_control_read(void *opaque, hwaddr offset, unsigned size)
assert(s->route_gpu_fiq < BCM2836_NCORES
&& s->route_gpu_irq < BCM2836_NCORES);
return ((uint32_t)s->route_gpu_fiq << 2) | s->route_gpu_irq;
} else if (offset == REG_LOCALTIMERROUTING) {
return s->route_localtimer;
} else if (offset == REG_LOCALTIMERCONTROL) {
return s->local_timer_control;
} else if (offset == REG_LOCALTIMERACK) {
return 0;
} else if (offset >= REG_TIMERCONTROL && offset < REG_MBOXCONTROL) {
return s->timercontrol[(offset - REG_TIMERCONTROL) >> 2];
} else if (offset >= REG_MBOXCONTROL && offset < REG_IRQSRC) {
@ -195,6 +275,12 @@ static void bcm2836_control_write(void *opaque, hwaddr offset,
if (offset == REG_GPU_ROUTE) {
s->route_gpu_irq = val & 0x3;
s->route_gpu_fiq = (val >> 2) & 0x3;
} else if (offset == REG_LOCALTIMERROUTING) {
s->route_localtimer = val & 7;
} else if (offset == REG_LOCALTIMERCONTROL) {
bcm2836_control_local_timer_control(s, val);
} else if (offset == REG_LOCALTIMERACK) {
bcm2836_control_local_timer_ack(s, val);
} else if (offset >= REG_TIMERCONTROL && offset < REG_MBOXCONTROL) {
s->timercontrol[(offset - REG_TIMERCONTROL) >> 2] = val & 0xff;
} else if (offset >= REG_MBOXCONTROL && offset < REG_IRQSRC) {
@ -227,6 +313,10 @@ static void bcm2836_control_reset(DeviceState *d)
s->route_gpu_irq = s->route_gpu_fiq = 0;
timer_del(&s->timer);
s->route_localtimer = 0;
s->local_timer_control = 0;
for (i = 0; i < BCM2836_NCORES; i++) {
s->timercontrol[i] = 0;
s->mailboxcontrol[i] = 0;
@ -263,11 +353,15 @@ static void bcm2836_control_init(Object *obj)
/* outputs to CPU cores */
qdev_init_gpio_out_named(dev, s->irq, "irq", BCM2836_NCORES);
qdev_init_gpio_out_named(dev, s->fiq, "fiq", BCM2836_NCORES);
/* create a qemu virtual timer */
timer_init_ns(&s->timer, QEMU_CLOCK_VIRTUAL,
bcm2836_control_local_timer_tick, s);
}
static const VMStateDescription vmstate_bcm2836_control = {
.name = TYPE_BCM2836_CONTROL,
.version_id = 1,
.version_id = 2,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32_ARRAY(mailboxes, BCM2836ControlState,
@ -277,6 +371,9 @@ static const VMStateDescription vmstate_bcm2836_control = {
VMSTATE_UINT32_ARRAY(timercontrol, BCM2836ControlState, BCM2836_NCORES),
VMSTATE_UINT32_ARRAY(mailboxcontrol, BCM2836ControlState,
BCM2836_NCORES),
VMSTATE_TIMER_V(timer, BCM2836ControlState, 2),
VMSTATE_UINT32_V(local_timer_control, BCM2836ControlState, 2),
VMSTATE_UINT8_V(route_localtimer, BCM2836ControlState, 2),
VMSTATE_END_OF_LIST()
}
};

9
include/hw/intc/bcm2836_control.h
View File

@ -5,6 +5,9 @@
* Rasperry Pi 2 emulation and refactoring Copyright (c) 2015, Microsoft
* Written by Andrew Baumann
*
* ARM Local Timer IRQ Copyright (c) 2019. Zoltán Baldaszti
* Added basic IRQ_TIMER interrupt support
*
* This code is licensed under the GNU GPLv2 and later.
*/
@ -12,6 +15,7 @@
#define BCM2836_CONTROL_H
#include "hw/sysbus.h"
#include "qemu/timer.h"
/* 4 mailboxes per core, for 16 total */
#define BCM2836_NCORES 4
@ -39,6 +43,11 @@ typedef struct BCM2836ControlState {
bool gpu_irq, gpu_fiq;
uint8_t timerirqs[BCM2836_NCORES];
/* local timer */
QEMUTimer timer;
uint32_t local_timer_control;
uint8_t route_localtimer;
/* interrupt source registers, post-routing (also input-derived; visible) */
uint32_t irqsrc[BCM2836_NCORES];
uint32_t fiqsrc[BCM2836_NCORES];