From df41cbd6bfa55dc3e69834f4402dbf776062c26e Mon Sep 17 00:00:00 2001 From: Alistair Francis Date: Fri, 18 Jun 2021 17:27:54 +1000 Subject: hw/timer: Initial commit of Ibex Timer Add support for the Ibex timer. This is used with the RISC-V mtime/mtimecmp similar to the SiFive CLINT. We currently don't support changing the prescale or the timervalue. Signed-off-by: Alistair Francis Reviewed-by: Bin Meng Message-id: 716fdea2244515ce86a2c46fe69467d013c03147.1624001156.git.alistair.francis@wdc.com --- hw/timer/ibex_timer.c | 305 ++++++++++++++++++++++++++++++++++++++++++++++++++ hw/timer/meson.build | 1 + 2 files changed, 306 insertions(+) create mode 100644 hw/timer/ibex_timer.c (limited to 'hw/timer') diff --git a/hw/timer/ibex_timer.c b/hw/timer/ibex_timer.c new file mode 100644 index 0000000000..5befb53506 --- /dev/null +++ b/hw/timer/ibex_timer.c @@ -0,0 +1,305 @@ +/* + * QEMU lowRISC Ibex Timer device + * + * Copyright (c) 2021 Western Digital + * + * For details check the documentation here: + * https://docs.opentitan.org/hw/ip/rv_timer/doc/ + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "qemu/timer.h" +#include "hw/timer/ibex_timer.h" +#include "hw/irq.h" +#include "hw/qdev-properties.h" +#include "target/riscv/cpu.h" +#include "migration/vmstate.h" + +REG32(CTRL, 0x00) + FIELD(CTRL, ACTIVE, 0, 1) +REG32(CFG0, 0x100) + FIELD(CFG0, PRESCALE, 0, 12) + FIELD(CFG0, STEP, 16, 8) +REG32(LOWER0, 0x104) +REG32(UPPER0, 0x108) +REG32(COMPARE_LOWER0, 0x10C) +REG32(COMPARE_UPPER0, 0x110) +REG32(INTR_ENABLE, 0x114) + FIELD(INTR_ENABLE, IE_0, 0, 1) +REG32(INTR_STATE, 0x118) + FIELD(INTR_STATE, IS_0, 0, 1) +REG32(INTR_TEST, 0x11C) + FIELD(INTR_TEST, T_0, 0, 1) + +static uint64_t cpu_riscv_read_rtc(uint32_t timebase_freq) +{ + return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + timebase_freq, NANOSECONDS_PER_SECOND); +} + +static void ibex_timer_update_irqs(IbexTimerState *s) +{ + CPUState *cs = qemu_get_cpu(0); + RISCVCPU *cpu = RISCV_CPU(cs); + uint64_t value = s->timer_compare_lower0 | + ((uint64_t)s->timer_compare_upper0 << 32); + uint64_t next, diff; + uint64_t now = cpu_riscv_read_rtc(s->timebase_freq); + + if (!(s->timer_ctrl & R_CTRL_ACTIVE_MASK)) { + /* Timer isn't active */ + return; + } + + /* Update the CPUs mtimecmp */ + cpu->env.timecmp = value; + + if (cpu->env.timecmp <= now) { + /* + * If the mtimecmp was in the past raise the interrupt now. + */ + riscv_cpu_update_mip(cpu, MIP_MTIP, BOOL_TO_MASK(1)); + if (s->timer_intr_enable & R_INTR_ENABLE_IE_0_MASK) { + s->timer_intr_state |= R_INTR_STATE_IS_0_MASK; + qemu_set_irq(s->irq, true); + } + return; + } + + /* Setup a timer to trigger the interrupt in the future */ + riscv_cpu_update_mip(cpu, MIP_MTIP, BOOL_TO_MASK(0)); + qemu_set_irq(s->irq, false); + + diff = cpu->env.timecmp - now; + next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + + muldiv64(diff, + NANOSECONDS_PER_SECOND, + s->timebase_freq); + + if (next < qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) { + /* We overflowed the timer, just set it as large as we can */ + timer_mod(cpu->env.timer, 0x7FFFFFFFFFFFFFFF); + } else { + timer_mod(cpu->env.timer, next); + } +} + +static void ibex_timer_cb(void *opaque) +{ + IbexTimerState *s = opaque; + CPUState *cs = qemu_get_cpu(0); + RISCVCPU *cpu = RISCV_CPU(cs); + + riscv_cpu_update_mip(cpu, MIP_MTIP, BOOL_TO_MASK(1)); + if (s->timer_intr_enable & R_INTR_ENABLE_IE_0_MASK) { + s->timer_intr_state |= R_INTR_STATE_IS_0_MASK; + qemu_set_irq(s->irq, true); + } +} + +static void ibex_timer_reset(DeviceState *dev) +{ + IbexTimerState *s = IBEX_TIMER(dev); + + CPUState *cpu = qemu_get_cpu(0); + CPURISCVState *env = cpu->env_ptr; + env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, + &ibex_timer_cb, s); + env->timecmp = 0; + + s->timer_ctrl = 0x00000000; + s->timer_cfg0 = 0x00010000; + s->timer_compare_lower0 = 0xFFFFFFFF; + s->timer_compare_upper0 = 0xFFFFFFFF; + s->timer_intr_enable = 0x00000000; + s->timer_intr_state = 0x00000000; + s->timer_intr_test = 0x00000000; + + ibex_timer_update_irqs(s); +} + +static uint64_t ibex_timer_read(void *opaque, hwaddr addr, + unsigned int size) +{ + IbexTimerState *s = opaque; + uint64_t now = cpu_riscv_read_rtc(s->timebase_freq); + uint64_t retvalue = 0; + + switch (addr >> 2) { + case R_CTRL: + retvalue = s->timer_ctrl; + break; + case R_CFG0: + retvalue = s->timer_cfg0; + break; + case R_LOWER0: + retvalue = now; + break; + case R_UPPER0: + retvalue = now >> 32; + break; + case R_COMPARE_LOWER0: + retvalue = s->timer_compare_lower0; + break; + case R_COMPARE_UPPER0: + retvalue = s->timer_compare_upper0; + break; + case R_INTR_ENABLE: + retvalue = s->timer_intr_enable; + break; + case R_INTR_STATE: + retvalue = s->timer_intr_state; + break; + case R_INTR_TEST: + retvalue = s->timer_intr_test; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr); + return 0; + } + + return retvalue; +} + +static void ibex_timer_write(void *opaque, hwaddr addr, + uint64_t val64, unsigned int size) +{ + IbexTimerState *s = opaque; + uint32_t val = val64; + + switch (addr >> 2) { + case R_CTRL: + s->timer_ctrl = val; + break; + case R_CFG0: + qemu_log_mask(LOG_UNIMP, "Changing prescale or step not supported"); + s->timer_cfg0 = val; + break; + case R_LOWER0: + qemu_log_mask(LOG_UNIMP, "Changing timer value is not supported"); + break; + case R_UPPER0: + qemu_log_mask(LOG_UNIMP, "Changing timer value is not supported"); + break; + case R_COMPARE_LOWER0: + s->timer_compare_lower0 = val; + ibex_timer_update_irqs(s); + break; + case R_COMPARE_UPPER0: + s->timer_compare_upper0 = val; + ibex_timer_update_irqs(s); + break; + case R_INTR_ENABLE: + s->timer_intr_enable = val; + break; + case R_INTR_STATE: + /* Write 1 to clear */ + s->timer_intr_state &= ~val; + break; + case R_INTR_TEST: + s->timer_intr_test = val; + if (s->timer_intr_enable & + s->timer_intr_test & + R_INTR_ENABLE_IE_0_MASK) { + s->timer_intr_state |= R_INTR_STATE_IS_0_MASK; + qemu_set_irq(s->irq, true); + } + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr); + } +} + +static const MemoryRegionOps ibex_timer_ops = { + .read = ibex_timer_read, + .write = ibex_timer_write, + .endianness = DEVICE_NATIVE_ENDIAN, + .impl.min_access_size = 4, + .impl.max_access_size = 4, +}; + +static int ibex_timer_post_load(void *opaque, int version_id) +{ + IbexTimerState *s = opaque; + + ibex_timer_update_irqs(s); + return 0; +} + +static const VMStateDescription vmstate_ibex_timer = { + .name = TYPE_IBEX_TIMER, + .version_id = 1, + .minimum_version_id = 1, + .post_load = ibex_timer_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT32(timer_ctrl, IbexTimerState), + VMSTATE_UINT32(timer_cfg0, IbexTimerState), + VMSTATE_UINT32(timer_compare_lower0, IbexTimerState), + VMSTATE_UINT32(timer_compare_upper0, IbexTimerState), + VMSTATE_UINT32(timer_intr_enable, IbexTimerState), + VMSTATE_UINT32(timer_intr_state, IbexTimerState), + VMSTATE_UINT32(timer_intr_test, IbexTimerState), + VMSTATE_END_OF_LIST() + } +}; + +static Property ibex_timer_properties[] = { + DEFINE_PROP_UINT32("timebase-freq", IbexTimerState, timebase_freq, 10000), + DEFINE_PROP_END_OF_LIST(), +}; + +static void ibex_timer_init(Object *obj) +{ + IbexTimerState *s = IBEX_TIMER(obj); + + sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq); + + memory_region_init_io(&s->mmio, obj, &ibex_timer_ops, s, + TYPE_IBEX_TIMER, 0x400); + sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio); +} + +static void ibex_timer_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->reset = ibex_timer_reset; + dc->vmsd = &vmstate_ibex_timer; + device_class_set_props(dc, ibex_timer_properties); +} + +static const TypeInfo ibex_timer_info = { + .name = TYPE_IBEX_TIMER, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(IbexTimerState), + .instance_init = ibex_timer_init, + .class_init = ibex_timer_class_init, +}; + +static void ibex_timer_register_types(void) +{ + type_register_static(&ibex_timer_info); +} + +type_init(ibex_timer_register_types) diff --git a/hw/timer/meson.build b/hw/timer/meson.build index 157f540ecd..1aa3cd2284 100644 --- a/hw/timer/meson.build +++ b/hw/timer/meson.build @@ -33,5 +33,6 @@ softmmu_ss.add(when: 'CONFIG_SSE_COUNTER', if_true: files('sse-counter.c')) softmmu_ss.add(when: 'CONFIG_SSE_TIMER', if_true: files('sse-timer.c')) softmmu_ss.add(when: 'CONFIG_STM32F2XX_TIMER', if_true: files('stm32f2xx_timer.c')) softmmu_ss.add(when: 'CONFIG_XILINX', if_true: files('xilinx_timer.c')) +specific_ss.add(when: 'CONFIG_IBEX', if_true: files('ibex_timer.c')) specific_ss.add(when: 'CONFIG_AVR_TIMER16', if_true: files('avr_timer16.c')) -- cgit v1.2.3