diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2021-02-19 14:45:45 +0000 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2021-03-08 17:20:01 +0000 |
commit | 0b8ceee822ae6d3bc4033c9b406c5f8d8c71ee6d (patch) | |
tree | e9f13fb705e2b8165988789a49ccb1b9cafd2f65 /hw/timer | |
parent | 0d10df30384c22c5f683cbfebc42cee6cf83fed4 (diff) |
hw/timer/sse-timer: Model the SSE Subsystem System Timer
The SSE-300 includes some timers which are a different kind to
those in the SSE-200. Model them.
These timers are documented in the SSE-123 Example Subsystem
Technical Reference Manual:
https://developer.arm.com/documentation/101370/latest/
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210219144617.4782-13-peter.maydell@linaro.org
Diffstat (limited to 'hw/timer')
-rw-r--r-- | hw/timer/Kconfig | 3 | ||||
-rw-r--r-- | hw/timer/meson.build | 1 | ||||
-rw-r--r-- | hw/timer/sse-timer.c | 470 | ||||
-rw-r--r-- | hw/timer/trace-events | 5 |
4 files changed, 479 insertions, 0 deletions
diff --git a/hw/timer/Kconfig b/hw/timer/Kconfig index e103c8872a..726be4f82c 100644 --- a/hw/timer/Kconfig +++ b/hw/timer/Kconfig @@ -45,5 +45,8 @@ config RENESAS_CMT config SSE_COUNTER bool +config SSE_TIMER + bool + config AVR_TIMER16 bool diff --git a/hw/timer/meson.build b/hw/timer/meson.build index 79a3012349..91ab2aa803 100644 --- a/hw/timer/meson.build +++ b/hw/timer/meson.build @@ -33,6 +33,7 @@ softmmu_ss.add(when: 'CONFIG_RASPI', if_true: files('bcm2835_systmr.c')) softmmu_ss.add(when: 'CONFIG_SH4', if_true: files('sh_timer.c')) softmmu_ss.add(when: 'CONFIG_SLAVIO', if_true: files('slavio_timer.c')) 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')) diff --git a/hw/timer/sse-timer.c b/hw/timer/sse-timer.c new file mode 100644 index 0000000000..8dbe6ac651 --- /dev/null +++ b/hw/timer/sse-timer.c @@ -0,0 +1,470 @@ +/* + * Arm SSE Subsystem System Timer + * + * Copyright (c) 2020 Linaro Limited + * Written by Peter Maydell + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 or + * (at your option) any later version. + */ + +/* + * This is a model of the "System timer" which is documented in + * the Arm SSE-123 Example Subsystem Technical Reference Manual: + * https://developer.arm.com/documentation/101370/latest/ + * + * The timer is based around a simple 64-bit incrementing counter + * (readable from CNTPCT_HI/LO). The timer fires when + * Counter - CompareValue >= 0. + * The CompareValue is guest-writable, via CNTP_CVAL_HI/LO. + * CNTP_TVAL is an alternative view of the CompareValue defined by + * TimerValue = CompareValue[31:0] - Counter[31:0] + * which can be both read and written. + * This part is similar to the generic timer in an Arm A-class CPU. + * + * The timer also has a separate auto-increment timer. When this + * timer is enabled, then the AutoIncrValue is set to: + * AutoIncrValue = Reload + Counter + * and this timer fires when + * Counter - AutoIncrValue >= 0 + * at which point, an interrupt is generated and the new AutoIncrValue + * is calculated. + * When the auto-increment timer is enabled, interrupt generation + * via the compare/timervalue registers is disabled. + */ +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "qemu/timer.h" +#include "qapi/error.h" +#include "trace.h" +#include "hw/timer/sse-timer.h" +#include "hw/timer/sse-counter.h" +#include "hw/sysbus.h" +#include "hw/irq.h" +#include "hw/registerfields.h" +#include "hw/clock.h" +#include "hw/qdev-clock.h" +#include "hw/qdev-properties.h" +#include "migration/vmstate.h" + +REG32(CNTPCT_LO, 0x0) +REG32(CNTPCT_HI, 0x4) +REG32(CNTFRQ, 0x10) +REG32(CNTP_CVAL_LO, 0x20) +REG32(CNTP_CVAL_HI, 0x24) +REG32(CNTP_TVAL, 0x28) +REG32(CNTP_CTL, 0x2c) + FIELD(CNTP_CTL, ENABLE, 0, 1) + FIELD(CNTP_CTL, IMASK, 1, 1) + FIELD(CNTP_CTL, ISTATUS, 2, 1) +REG32(CNTP_AIVAL_LO, 0x40) +REG32(CNTP_AIVAL_HI, 0x44) +REG32(CNTP_AIVAL_RELOAD, 0x48) +REG32(CNTP_AIVAL_CTL, 0x4c) + FIELD(CNTP_AIVAL_CTL, EN, 0, 1) + FIELD(CNTP_AIVAL_CTL, CLR, 1, 1) +REG32(CNTP_CFG, 0x50) + FIELD(CNTP_CFG, AIVAL, 0, 4) +#define R_CNTP_CFG_AIVAL_IMPLEMENTED 1 +REG32(PID4, 0xFD0) +REG32(PID5, 0xFD4) +REG32(PID6, 0xFD8) +REG32(PID7, 0xFDC) +REG32(PID0, 0xFE0) +REG32(PID1, 0xFE4) +REG32(PID2, 0xFE8) +REG32(PID3, 0xFEC) +REG32(CID0, 0xFF0) +REG32(CID1, 0xFF4) +REG32(CID2, 0xFF8) +REG32(CID3, 0xFFC) + +/* PID/CID values */ +static const int timer_id[] = { + 0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */ + 0xb7, 0xb0, 0x0b, 0x00, /* PID0..PID3 */ + 0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */ +}; + +static bool sse_is_autoinc(SSETimer *s) +{ + return (s->cntp_aival_ctl & R_CNTP_AIVAL_CTL_EN_MASK) != 0; +} + +static bool sse_enabled(SSETimer *s) +{ + return (s->cntp_ctl & R_CNTP_CTL_ENABLE_MASK) != 0; +} + +static uint64_t sse_cntpct(SSETimer *s) +{ + /* Return the CNTPCT value for the current time */ + return sse_counter_for_timestamp(s->counter, + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)); +} + +static bool sse_timer_status(SSETimer *s) +{ + /* + * Return true if timer condition is met. This is used for both + * the CNTP_CTL.ISTATUS bit and for whether (unless masked) we + * assert our IRQ. + * The documentation is unclear about the behaviour of ISTATUS when + * in autoincrement mode; we assume that it follows CNTP_AIVAL_CTL.CLR + * (ie whether the autoincrement timer is asserting the interrupt). + */ + if (!sse_enabled(s)) { + return false; + } + + if (sse_is_autoinc(s)) { + return s->cntp_aival_ctl & R_CNTP_AIVAL_CTL_CLR_MASK; + } else { + return sse_cntpct(s) >= s->cntp_cval; + } +} + +static void sse_update_irq(SSETimer *s) +{ + bool irqstate = (!(s->cntp_ctl & R_CNTP_CTL_IMASK_MASK) && + sse_timer_status(s)); + + qemu_set_irq(s->irq, irqstate); +} + +static void sse_set_timer(SSETimer *s, uint64_t nexttick) +{ + /* Set the timer to expire at nexttick */ + uint64_t expiry = sse_counter_tick_to_time(s->counter, nexttick); + + if (expiry <= INT64_MAX) { + timer_mod_ns(&s->timer, expiry); + } else { + /* + * nexttick is so far in the future that it would overflow the + * signed 64-bit range of a QEMUTimer. Since timer_mod_ns() + * expiry times are absolute, not relative, we are never going + * to be able to set the timer to this value, so we must just + * assume that guest execution can never run so long that it + * reaches the theoretical point when the timer fires. + * This is also the code path for "counter is not running", + * which is signalled by expiry == UINT64_MAX. + */ + timer_del(&s->timer); + } +} + +static void sse_recalc_timer(SSETimer *s) +{ + /* Recalculate the normal timer */ + uint64_t count, nexttick; + + if (sse_is_autoinc(s)) { + return; + } + + if (!sse_enabled(s)) { + timer_del(&s->timer); + return; + } + + count = sse_cntpct(s); + + if (count >= s->cntp_cval) { + /* + * Timer condition already met. In theory we have a transition when + * the count rolls back over to 0, but that is so far in the future + * that it is not representable as a timer_mod() expiry, so in + * fact sse_set_timer() will always just delete the timer. + */ + nexttick = UINT64_MAX; + } else { + /* Next transition is when count hits cval */ + nexttick = s->cntp_cval; + } + sse_set_timer(s, nexttick); + sse_update_irq(s); +} + +static void sse_autoinc(SSETimer *s) +{ + /* Auto-increment the AIVAL, and set the timer accordingly */ + s->cntp_aival = sse_cntpct(s) + s->cntp_aival_reload; + sse_set_timer(s, s->cntp_aival); +} + +static void sse_timer_cb(void *opaque) +{ + SSETimer *s = SSE_TIMER(opaque); + + if (sse_is_autoinc(s)) { + uint64_t count = sse_cntpct(s); + + if (count >= s->cntp_aival) { + /* Timer condition met, set CLR and do another autoinc */ + s->cntp_aival_ctl |= R_CNTP_AIVAL_CTL_CLR_MASK; + s->cntp_aival = count + s->cntp_aival_reload; + } + sse_set_timer(s, s->cntp_aival); + sse_update_irq(s); + } else { + sse_recalc_timer(s); + } +} + +static uint64_t sse_timer_read(void *opaque, hwaddr offset, unsigned size) +{ + SSETimer *s = SSE_TIMER(opaque); + uint64_t r; + + switch (offset) { + case A_CNTPCT_LO: + r = extract64(sse_cntpct(s), 0, 32); + break; + case A_CNTPCT_HI: + r = extract64(sse_cntpct(s), 32, 32); + break; + case A_CNTFRQ: + r = s->cntfrq; + break; + case A_CNTP_CVAL_LO: + r = extract64(s->cntp_cval, 0, 32); + break; + case A_CNTP_CVAL_HI: + r = extract64(s->cntp_cval, 32, 32); + break; + case A_CNTP_TVAL: + r = extract64(s->cntp_cval - sse_cntpct(s), 0, 32); + break; + case A_CNTP_CTL: + r = s->cntp_ctl; + if (sse_timer_status(s)) { + r |= R_CNTP_CTL_ISTATUS_MASK; + } + break; + case A_CNTP_AIVAL_LO: + r = extract64(s->cntp_aival, 0, 32); + break; + case A_CNTP_AIVAL_HI: + r = extract64(s->cntp_aival, 32, 32); + break; + case A_CNTP_AIVAL_RELOAD: + r = s->cntp_aival_reload; + break; + case A_CNTP_AIVAL_CTL: + /* + * All the bits of AIVAL_CTL are documented as WO, but this is probably + * a documentation error. We implement them as readable. + */ + r = s->cntp_aival_ctl; + break; + case A_CNTP_CFG: + r = R_CNTP_CFG_AIVAL_IMPLEMENTED << R_CNTP_CFG_AIVAL_SHIFT; + break; + case A_PID4 ... A_CID3: + r = timer_id[(offset - A_PID4) / 4]; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "SSE System Timer read: bad offset 0x%x", + (unsigned) offset); + r = 0; + break; + } + + trace_sse_timer_read(offset, r, size); + return r; +} + +static void sse_timer_write(void *opaque, hwaddr offset, uint64_t value, + unsigned size) +{ + SSETimer *s = SSE_TIMER(opaque); + + trace_sse_timer_write(offset, value, size); + + switch (offset) { + case A_CNTFRQ: + s->cntfrq = value; + break; + case A_CNTP_CVAL_LO: + s->cntp_cval = deposit64(s->cntp_cval, 0, 32, value); + sse_recalc_timer(s); + break; + case A_CNTP_CVAL_HI: + s->cntp_cval = deposit64(s->cntp_cval, 32, 32, value); + sse_recalc_timer(s); + break; + case A_CNTP_TVAL: + s->cntp_cval = sse_cntpct(s) + sextract64(value, 0, 32); + sse_recalc_timer(s); + break; + case A_CNTP_CTL: + { + uint32_t old_ctl = s->cntp_ctl; + value &= R_CNTP_CTL_ENABLE_MASK | R_CNTP_CTL_IMASK_MASK; + s->cntp_ctl = value; + if ((old_ctl ^ s->cntp_ctl) & R_CNTP_CTL_ENABLE_MASK) { + if (sse_enabled(s)) { + if (sse_is_autoinc(s)) { + sse_autoinc(s); + } else { + sse_recalc_timer(s); + } + } + } + sse_update_irq(s); + break; + } + case A_CNTP_AIVAL_RELOAD: + s->cntp_aival_reload = value; + break; + case A_CNTP_AIVAL_CTL: + { + uint32_t old_ctl = s->cntp_aival_ctl; + + /* EN bit is writeable; CLR bit is write-0-to-clear, write-1-ignored */ + s->cntp_aival_ctl &= ~R_CNTP_AIVAL_CTL_EN_MASK; + s->cntp_aival_ctl |= value & R_CNTP_AIVAL_CTL_EN_MASK; + if (!(value & R_CNTP_AIVAL_CTL_CLR_MASK)) { + s->cntp_aival_ctl &= ~R_CNTP_AIVAL_CTL_CLR_MASK; + } + if ((old_ctl ^ s->cntp_aival_ctl) & R_CNTP_AIVAL_CTL_EN_MASK) { + /* Auto-increment toggled on/off */ + if (sse_enabled(s)) { + if (sse_is_autoinc(s)) { + sse_autoinc(s); + } else { + sse_recalc_timer(s); + } + } + } + sse_update_irq(s); + break; + } + case A_CNTPCT_LO: + case A_CNTPCT_HI: + case A_CNTP_CFG: + case A_CNTP_AIVAL_LO: + case A_CNTP_AIVAL_HI: + case A_PID4 ... A_CID3: + qemu_log_mask(LOG_GUEST_ERROR, + "SSE System Timer write: write to RO offset 0x%x\n", + (unsigned)offset); + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "SSE System Timer write: bad offset 0x%x\n", + (unsigned)offset); + break; + } +} + +static const MemoryRegionOps sse_timer_ops = { + .read = sse_timer_read, + .write = sse_timer_write, + .endianness = DEVICE_LITTLE_ENDIAN, + .valid.min_access_size = 4, + .valid.max_access_size = 4, +}; + +static void sse_timer_reset(DeviceState *dev) +{ + SSETimer *s = SSE_TIMER(dev); + + trace_sse_timer_reset(); + + timer_del(&s->timer); + s->cntfrq = 0; + s->cntp_ctl = 0; + s->cntp_cval = 0; + s->cntp_aival = 0; + s->cntp_aival_ctl = 0; + s->cntp_aival_reload = 0; +} + +static void sse_timer_counter_callback(Notifier *notifier, void *data) +{ + SSETimer *s = container_of(notifier, SSETimer, counter_notifier); + + /* System counter told us we need to recalculate */ + if (sse_enabled(s)) { + if (sse_is_autoinc(s)) { + sse_set_timer(s, s->cntp_aival); + } else { + sse_recalc_timer(s); + } + } +} + +static void sse_timer_init(Object *obj) +{ + SysBusDevice *sbd = SYS_BUS_DEVICE(obj); + SSETimer *s = SSE_TIMER(obj); + + memory_region_init_io(&s->iomem, obj, &sse_timer_ops, + s, "sse-timer", 0x1000); + sysbus_init_mmio(sbd, &s->iomem); + sysbus_init_irq(sbd, &s->irq); +} + +static void sse_timer_realize(DeviceState *dev, Error **errp) +{ + SSETimer *s = SSE_TIMER(dev); + + if (!s->counter) { + error_setg(errp, "counter property was not set"); + } + + s->counter_notifier.notify = sse_timer_counter_callback; + sse_counter_register_consumer(s->counter, &s->counter_notifier); + + timer_init_ns(&s->timer, QEMU_CLOCK_VIRTUAL, sse_timer_cb, s); +} + +static const VMStateDescription sse_timer_vmstate = { + .name = "sse-timer", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_TIMER(timer, SSETimer), + VMSTATE_UINT32(cntfrq, SSETimer), + VMSTATE_UINT32(cntp_ctl, SSETimer), + VMSTATE_UINT64(cntp_cval, SSETimer), + VMSTATE_UINT64(cntp_aival, SSETimer), + VMSTATE_UINT32(cntp_aival_ctl, SSETimer), + VMSTATE_UINT32(cntp_aival_reload, SSETimer), + VMSTATE_END_OF_LIST() + } +}; + +static Property sse_timer_properties[] = { + DEFINE_PROP_LINK("counter", SSETimer, counter, TYPE_SSE_COUNTER, SSECounter *), + DEFINE_PROP_END_OF_LIST(), +}; + +static void sse_timer_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = sse_timer_realize; + dc->vmsd = &sse_timer_vmstate; + dc->reset = sse_timer_reset; + device_class_set_props(dc, sse_timer_properties); +} + +static const TypeInfo sse_timer_info = { + .name = TYPE_SSE_TIMER, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(SSETimer), + .instance_init = sse_timer_init, + .class_init = sse_timer_class_init, +}; + +static void sse_timer_register_types(void) +{ + type_register_static(&sse_timer_info); +} + +type_init(sse_timer_register_types); diff --git a/hw/timer/trace-events b/hw/timer/trace-events index bb9c100087..f8b9db25c2 100644 --- a/hw/timer/trace-events +++ b/hw/timer/trace-events @@ -100,3 +100,8 @@ sse_counter_control_write(uint64_t offset, uint64_t data, unsigned size) "SSE sy sse_counter_status_read(uint64_t offset, uint64_t data, unsigned size) "SSE system counter status frame read: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u" sse_counter_status_write(uint64_t offset, uint64_t data, unsigned size) "SSE system counter status frame write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u" sse_counter_reset(void) "SSE system counter: reset" + +# sse_timer.c +sse_timer_read(uint64_t offset, uint64_t data, unsigned size) "SSE system timer read: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u" +sse_timer_write(uint64_t offset, uint64_t data, unsigned size) "SSE system timer write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u" +sse_timer_reset(void) "SSE system timer: reset" |