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/*
* SiFive CLINT (Core Local Interruptor)
*
* Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
* Copyright (c) 2017 SiFive, Inc.
*
* This provides real-time clock, timer and interprocessor interrupts.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "hw/sysbus.h"
#include "target/riscv/cpu.h"
#include "hw/riscv/sifive_clint.h"
#include "qemu/timer.h"
/* See: riscv-pk/machine/sbi_entry.S and arch/riscv/kernel/time.c */
#define TIMER_FREQ (10 * 1000 * 1000)
static uint64_t cpu_riscv_read_rtc(void)
{
return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), TIMER_FREQ,
NANOSECONDS_PER_SECOND);
}
/*
* Called when timecmp is written to update the QEMU timer or immediately
* trigger timer interrupt if mtimecmp <= current timer value.
*/
static void sifive_clint_write_timecmp(RISCVCPU *cpu, uint64_t value)
{
uint64_t next;
uint64_t diff;
uint64_t rtc_r = cpu_riscv_read_rtc();
cpu->env.timecmp = value;
if (cpu->env.timecmp <= rtc_r) {
/* if we're setting an MTIMECMP value in the "past",
immediately raise the timer interrupt */
riscv_set_local_interrupt(cpu, MIP_MTIP, 1);
return;
}
/* otherwise, set up the future timer interrupt */
riscv_set_local_interrupt(cpu, MIP_MTIP, 0);
diff = cpu->env.timecmp - rtc_r;
/* back to ns (note args switched in muldiv64) */
next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
muldiv64(diff, NANOSECONDS_PER_SECOND, TIMER_FREQ);
timer_mod(cpu->env.timer, next);
}
/*
* Callback used when the timer set using timer_mod expires.
* Should raise the timer interrupt line
*/
static void sifive_clint_timer_cb(void *opaque)
{
RISCVCPU *cpu = opaque;
riscv_set_local_interrupt(cpu, MIP_MTIP, 1);
}
/* CPU wants to read rtc or timecmp register */
static uint64_t sifive_clint_read(void *opaque, hwaddr addr, unsigned size)
{
SiFiveCLINTState *clint = opaque;
if (addr >= clint->sip_base &&
addr < clint->sip_base + (clint->num_harts << 2)) {
size_t hartid = (addr - clint->sip_base) >> 2;
CPUState *cpu = qemu_get_cpu(hartid);
CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
if (!env) {
error_report("clint: invalid timecmp hartid: %zu", hartid);
} else if ((addr & 0x3) == 0) {
return (env->mip & MIP_MSIP) > 0;
} else {
error_report("clint: invalid read: %08x", (uint32_t)addr);
return 0;
}
} else if (addr >= clint->timecmp_base &&
addr < clint->timecmp_base + (clint->num_harts << 3)) {
size_t hartid = (addr - clint->timecmp_base) >> 3;
CPUState *cpu = qemu_get_cpu(hartid);
CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
if (!env) {
error_report("clint: invalid timecmp hartid: %zu", hartid);
} else if ((addr & 0x7) == 0) {
/* timecmp_lo */
uint64_t timecmp = env->timecmp;
return timecmp & 0xFFFFFFFF;
} else if ((addr & 0x7) == 4) {
/* timecmp_hi */
uint64_t timecmp = env->timecmp;
return (timecmp >> 32) & 0xFFFFFFFF;
} else {
error_report("clint: invalid read: %08x", (uint32_t)addr);
return 0;
}
} else if (addr == clint->time_base) {
/* time_lo */
return cpu_riscv_read_rtc() & 0xFFFFFFFF;
} else if (addr == clint->time_base + 4) {
/* time_hi */
return (cpu_riscv_read_rtc() >> 32) & 0xFFFFFFFF;
}
error_report("clint: invalid read: %08x", (uint32_t)addr);
return 0;
}
/* CPU wrote to rtc or timecmp register */
static void sifive_clint_write(void *opaque, hwaddr addr, uint64_t value,
unsigned size)
{
SiFiveCLINTState *clint = opaque;
if (addr >= clint->sip_base &&
addr < clint->sip_base + (clint->num_harts << 2)) {
size_t hartid = (addr - clint->sip_base) >> 2;
CPUState *cpu = qemu_get_cpu(hartid);
CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
if (!env) {
error_report("clint: invalid timecmp hartid: %zu", hartid);
} else if ((addr & 0x3) == 0) {
riscv_set_local_interrupt(RISCV_CPU(cpu), MIP_MSIP, value != 0);
} else {
error_report("clint: invalid sip write: %08x", (uint32_t)addr);
}
return;
} else if (addr >= clint->timecmp_base &&
addr < clint->timecmp_base + (clint->num_harts << 3)) {
size_t hartid = (addr - clint->timecmp_base) >> 3;
CPUState *cpu = qemu_get_cpu(hartid);
CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
if (!env) {
error_report("clint: invalid timecmp hartid: %zu", hartid);
} else if ((addr & 0x7) == 0) {
/* timecmp_lo */
uint64_t timecmp = env->timecmp;
sifive_clint_write_timecmp(RISCV_CPU(cpu),
timecmp << 32 | (value & 0xFFFFFFFF));
return;
} else if ((addr & 0x7) == 4) {
/* timecmp_hi */
uint64_t timecmp = env->timecmp;
sifive_clint_write_timecmp(RISCV_CPU(cpu),
value << 32 | (timecmp & 0xFFFFFFFF));
} else {
error_report("clint: invalid timecmp write: %08x", (uint32_t)addr);
}
return;
} else if (addr == clint->time_base) {
/* time_lo */
error_report("clint: time_lo write not implemented");
return;
} else if (addr == clint->time_base + 4) {
/* time_hi */
error_report("clint: time_hi write not implemented");
return;
}
error_report("clint: invalid write: %08x", (uint32_t)addr);
}
static const MemoryRegionOps sifive_clint_ops = {
.read = sifive_clint_read,
.write = sifive_clint_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid = {
.min_access_size = 4,
.max_access_size = 4
}
};
static Property sifive_clint_properties[] = {
DEFINE_PROP_UINT32("num-harts", SiFiveCLINTState, num_harts, 0),
DEFINE_PROP_UINT32("sip-base", SiFiveCLINTState, sip_base, 0),
DEFINE_PROP_UINT32("timecmp-base", SiFiveCLINTState, timecmp_base, 0),
DEFINE_PROP_UINT32("time-base", SiFiveCLINTState, time_base, 0),
DEFINE_PROP_UINT32("aperture-size", SiFiveCLINTState, aperture_size, 0),
DEFINE_PROP_END_OF_LIST(),
};
static void sifive_clint_realize(DeviceState *dev, Error **errp)
{
SiFiveCLINTState *s = SIFIVE_CLINT(dev);
memory_region_init_io(&s->mmio, OBJECT(dev), &sifive_clint_ops, s,
TYPE_SIFIVE_CLINT, s->aperture_size);
sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
}
static void sifive_clint_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = sifive_clint_realize;
dc->props = sifive_clint_properties;
}
static const TypeInfo sifive_clint_info = {
.name = TYPE_SIFIVE_CLINT,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(SiFiveCLINTState),
.class_init = sifive_clint_class_init,
};
static void sifive_clint_register_types(void)
{
type_register_static(&sifive_clint_info);
}
type_init(sifive_clint_register_types)
/*
* Create CLINT device.
*/
DeviceState *sifive_clint_create(hwaddr addr, hwaddr size, uint32_t num_harts,
uint32_t sip_base, uint32_t timecmp_base, uint32_t time_base)
{
int i;
for (i = 0; i < num_harts; i++) {
CPUState *cpu = qemu_get_cpu(i);
CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
if (!env) {
continue;
}
env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
&sifive_clint_timer_cb, cpu);
env->timecmp = 0;
}
DeviceState *dev = qdev_create(NULL, TYPE_SIFIVE_CLINT);
qdev_prop_set_uint32(dev, "num-harts", num_harts);
qdev_prop_set_uint32(dev, "sip-base", sip_base);
qdev_prop_set_uint32(dev, "timecmp-base", timecmp_base);
qdev_prop_set_uint32(dev, "time-base", time_base);
qdev_prop_set_uint32(dev, "aperture-size", size);
qdev_init_nofail(dev);
sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
return dev;
}
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