qemu/hw/misc/imx6_src.c
Alex Bennée 4881658a4b hw/misc/imx6_src: defer clearing of SRC_SCR reset bits
The arm_reset_cpu/set_cpu_on/set_cpu_off() functions do their work
asynchronously in the target vCPUs context. As a result we need to
ensure the SRC_SCR reset bits correctly report the reset status at the
right time. To do this we defer the clearing of the bit with an async
job which will run after the work queued by ARM powerctl functions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
2017-02-24 10:32:46 +00:00

306 lines
8.8 KiB
C

/*
* IMX6 System Reset Controller
*
* Copyright (c) 2015 Jean-Christophe Dubois <jcd@tribudubois.net>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "hw/misc/imx6_src.h"
#include "sysemu/sysemu.h"
#include "qemu/bitops.h"
#include "qemu/log.h"
#include "arm-powerctl.h"
#include "qom/cpu.h"
#ifndef DEBUG_IMX6_SRC
#define DEBUG_IMX6_SRC 0
#endif
#define DPRINTF(fmt, args...) \
do { \
if (DEBUG_IMX6_SRC) { \
fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX6_SRC, \
__func__, ##args); \
} \
} while (0)
static const char *imx6_src_reg_name(uint32_t reg)
{
static char unknown[20];
switch (reg) {
case SRC_SCR:
return "SRC_SCR";
case SRC_SBMR1:
return "SRC_SBMR1";
case SRC_SRSR:
return "SRC_SRSR";
case SRC_SISR:
return "SRC_SISR";
case SRC_SIMR:
return "SRC_SIMR";
case SRC_SBMR2:
return "SRC_SBMR2";
case SRC_GPR1:
return "SRC_GPR1";
case SRC_GPR2:
return "SRC_GPR2";
case SRC_GPR3:
return "SRC_GPR3";
case SRC_GPR4:
return "SRC_GPR4";
case SRC_GPR5:
return "SRC_GPR5";
case SRC_GPR6:
return "SRC_GPR6";
case SRC_GPR7:
return "SRC_GPR7";
case SRC_GPR8:
return "SRC_GPR8";
case SRC_GPR9:
return "SRC_GPR9";
case SRC_GPR10:
return "SRC_GPR10";
default:
sprintf(unknown, "%d ?", reg);
return unknown;
}
}
static const VMStateDescription vmstate_imx6_src = {
.name = TYPE_IMX6_SRC,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32_ARRAY(regs, IMX6SRCState, SRC_MAX),
VMSTATE_END_OF_LIST()
},
};
static void imx6_src_reset(DeviceState *dev)
{
IMX6SRCState *s = IMX6_SRC(dev);
DPRINTF("\n");
memset(s->regs, 0, sizeof(s->regs));
/* Set reset values */
s->regs[SRC_SCR] = 0x521;
s->regs[SRC_SRSR] = 0x1;
s->regs[SRC_SIMR] = 0x1F;
}
static uint64_t imx6_src_read(void *opaque, hwaddr offset, unsigned size)
{
uint32_t value = 0;
IMX6SRCState *s = (IMX6SRCState *)opaque;
uint32_t index = offset >> 2;
if (index < SRC_MAX) {
value = s->regs[index];
} else {
qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
HWADDR_PRIx "\n", TYPE_IMX6_SRC, __func__, offset);
}
DPRINTF("reg[%s] => 0x%" PRIx32 "\n", imx6_src_reg_name(index), value);
return value;
}
/* The reset is asynchronous so we need to defer clearing the reset
* bit until the work is completed.
*/
struct SRCSCRResetInfo {
IMX6SRCState *s;
int reset_bit;
};
static void imx6_clear_reset_bit(CPUState *cpu, run_on_cpu_data data)
{
struct SRCSCRResetInfo *ri = data.host_ptr;
IMX6SRCState *s = ri->s;
assert(qemu_mutex_iothread_locked());
s->regs[SRC_SCR] = deposit32(s->regs[SRC_SCR], ri->reset_bit, 1, 0);
DPRINTF("reg[%s] <= 0x%" PRIx32 "\n",
imx6_src_reg_name(SRC_SCR), s->regs[SRC_SCR]);
g_free(ri);
}
static void imx6_defer_clear_reset_bit(int cpuid,
IMX6SRCState *s,
unsigned long reset_shift)
{
struct SRCSCRResetInfo *ri;
ri = g_malloc(sizeof(struct SRCSCRResetInfo));
ri->s = s;
ri->reset_bit = reset_shift;
async_run_on_cpu(arm_get_cpu_by_id(cpuid), imx6_clear_reset_bit,
RUN_ON_CPU_HOST_PTR(ri));
}
static void imx6_src_write(void *opaque, hwaddr offset, uint64_t value,
unsigned size)
{
IMX6SRCState *s = (IMX6SRCState *)opaque;
uint32_t index = offset >> 2;
unsigned long change_mask;
unsigned long current_value = value;
if (index >= SRC_MAX) {
qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
HWADDR_PRIx "\n", TYPE_IMX6_SRC, __func__, offset);
return;
}
DPRINTF("reg[%s] <= 0x%" PRIx32 "\n", imx6_src_reg_name(index),
(uint32_t)current_value);
change_mask = s->regs[index] ^ (uint32_t)current_value;
switch (index) {
case SRC_SCR:
/*
* On real hardware when the system reset controller starts a
* secondary CPU it runs through some boot ROM code which reads
* the SRC_GPRX registers controlling the start address and branches
* to it.
* Here we are taking a short cut and branching directly to the
* requested address (we don't want to run the boot ROM code inside
* QEMU)
*/
if (EXTRACT(change_mask, CORE3_ENABLE)) {
if (EXTRACT(current_value, CORE3_ENABLE)) {
/* CORE 3 is brought up */
arm_set_cpu_on(3, s->regs[SRC_GPR7], s->regs[SRC_GPR8],
3, false);
} else {
/* CORE 3 is shut down */
arm_set_cpu_off(3);
}
/* We clear the reset bits as the processor changed state */
imx6_defer_clear_reset_bit(3, s, CORE3_RST_SHIFT);
clear_bit(CORE3_RST_SHIFT, &change_mask);
}
if (EXTRACT(change_mask, CORE2_ENABLE)) {
if (EXTRACT(current_value, CORE2_ENABLE)) {
/* CORE 2 is brought up */
arm_set_cpu_on(2, s->regs[SRC_GPR5], s->regs[SRC_GPR6],
3, false);
} else {
/* CORE 2 is shut down */
arm_set_cpu_off(2);
}
/* We clear the reset bits as the processor changed state */
imx6_defer_clear_reset_bit(2, s, CORE2_RST_SHIFT);
clear_bit(CORE2_RST_SHIFT, &change_mask);
}
if (EXTRACT(change_mask, CORE1_ENABLE)) {
if (EXTRACT(current_value, CORE1_ENABLE)) {
/* CORE 1 is brought up */
arm_set_cpu_on(1, s->regs[SRC_GPR3], s->regs[SRC_GPR4],
3, false);
} else {
/* CORE 1 is shut down */
arm_set_cpu_off(1);
}
/* We clear the reset bits as the processor changed state */
imx6_defer_clear_reset_bit(1, s, CORE1_RST_SHIFT);
clear_bit(CORE1_RST_SHIFT, &change_mask);
}
if (EXTRACT(change_mask, CORE0_RST)) {
arm_reset_cpu(0);
imx6_defer_clear_reset_bit(0, s, CORE0_RST_SHIFT);
}
if (EXTRACT(change_mask, CORE1_RST)) {
arm_reset_cpu(1);
imx6_defer_clear_reset_bit(1, s, CORE1_RST_SHIFT);
}
if (EXTRACT(change_mask, CORE2_RST)) {
arm_reset_cpu(2);
imx6_defer_clear_reset_bit(2, s, CORE2_RST_SHIFT);
}
if (EXTRACT(change_mask, CORE3_RST)) {
arm_reset_cpu(3);
imx6_defer_clear_reset_bit(3, s, CORE3_RST_SHIFT);
}
if (EXTRACT(change_mask, SW_IPU2_RST)) {
/* We pretend the IPU2 is reset */
clear_bit(SW_IPU2_RST_SHIFT, &current_value);
}
if (EXTRACT(change_mask, SW_IPU1_RST)) {
/* We pretend the IPU1 is reset */
clear_bit(SW_IPU1_RST_SHIFT, &current_value);
}
s->regs[index] = current_value;
break;
default:
s->regs[index] = current_value;
break;
}
}
static const struct MemoryRegionOps imx6_src_ops = {
.read = imx6_src_read,
.write = imx6_src_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid = {
/*
* Our device would not work correctly if the guest was doing
* unaligned access. This might not be a limitation on the real
* device but in practice there is no reason for a guest to access
* this device unaligned.
*/
.min_access_size = 4,
.max_access_size = 4,
.unaligned = false,
},
};
static void imx6_src_realize(DeviceState *dev, Error **errp)
{
IMX6SRCState *s = IMX6_SRC(dev);
memory_region_init_io(&s->iomem, OBJECT(dev), &imx6_src_ops, s,
TYPE_IMX6_SRC, 0x1000);
sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
}
static void imx6_src_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = imx6_src_realize;
dc->reset = imx6_src_reset;
dc->vmsd = &vmstate_imx6_src;
dc->desc = "i.MX6 System Reset Controller";
}
static const TypeInfo imx6_src_info = {
.name = TYPE_IMX6_SRC,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(IMX6SRCState),
.class_init = imx6_src_class_init,
};
static void imx6_src_register_types(void)
{
type_register_static(&imx6_src_info);
}
type_init(imx6_src_register_types)