qemu-e2k/target/loongarch/constant_timer.c
Xiaojuan Yang dd615fa48d target/loongarch: Add constant timer support
Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220606124333.2060567-25-yangxiaojuan@loongson.cn>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-06-06 18:09:03 +00:00

65 lines
1.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* QEMU LoongArch constant timer support
*
* Copyright (c) 2021 Loongson Technology Corporation Limited
*/
#include "qemu/osdep.h"
#include "qemu/timer.h"
#include "cpu.h"
#include "internals.h"
#include "cpu-csr.h"
#define TIMER_PERIOD 10 /* 10 ns period for 100 MHz frequency */
#define CONSTANT_TIMER_TICK_MASK 0xfffffffffffcUL
#define CONSTANT_TIMER_ENABLE 0x1UL
uint64_t cpu_loongarch_get_constant_timer_counter(LoongArchCPU *cpu)
{
return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / TIMER_PERIOD;
}
uint64_t cpu_loongarch_get_constant_timer_ticks(LoongArchCPU *cpu)
{
uint64_t now, expire;
now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
expire = timer_expire_time_ns(&cpu->timer);
return (expire - now) / TIMER_PERIOD;
}
void cpu_loongarch_store_constant_timer_config(LoongArchCPU *cpu,
uint64_t value)
{
CPULoongArchState *env = &cpu->env;
uint64_t now, next;
env->CSR_TCFG = value;
if (value & CONSTANT_TIMER_ENABLE) {
now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
next = now + (value & CONSTANT_TIMER_TICK_MASK) * TIMER_PERIOD;
timer_mod(&cpu->timer, next);
} else {
timer_del(&cpu->timer);
}
}
void loongarch_constant_timer_cb(void *opaque)
{
LoongArchCPU *cpu = opaque;
CPULoongArchState *env = &cpu->env;
uint64_t now, next;
if (FIELD_EX64(env->CSR_TCFG, CSR_TCFG, PERIODIC)) {
now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
next = now + (env->CSR_TCFG & CONSTANT_TIMER_TICK_MASK) * TIMER_PERIOD;
timer_mod(&cpu->timer, next);
} else {
env->CSR_TCFG = FIELD_DP64(env->CSR_TCFG, CSR_TCFG, EN, 0);
}
loongarch_cpu_set_irq(opaque, IRQ_TIMER, 1);
}