qemu/hw/misc/imx6_src.c
Peter Maydell 5e2fb7c598 hw/misc/imx6_src: Don't crash trying to reset missing CPUs
Commit 4881658a4b introduced a call to arm_get_cpu_by_id(),
and Coverity noticed that we weren't checking that it didn't
return NULL (CID 1371652).

Normally this won't happen (because all 4 CPUs are expected
to exist), but it's possible the user requested fewer CPUs
on the command line. Handle this possibility by silently
doing nothing, which is the same behaviour as before commit
4881658a4b and also how we handle the other CPU operations
(since we ignore the INVALID_PARAM returns from arm_set_cpu_on()
and friends).

There is a slight behavioural difference to the pre-4881658a4b
situation: the "reset this core" bit will remain set rather
than not being permitted to be set. The imx6 datasheet is
unclear about the behaviour in this odd corner case, so we
opt for the simpler code rather than complicated logic to
maintain identical behaviour.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1488542374-1256-1-git-send-email-peter.maydell@linaro.org
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-03-14 16:13:22 +00:00

310 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;
CPUState *cpu = arm_get_cpu_by_id(cpuid);
if (!cpu) {
return;
}
ri = g_malloc(sizeof(struct SRCSCRResetInfo));
ri->s = s;
ri->reset_bit = reset_shift;
async_run_on_cpu(cpu, 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)