+++ /dev/null
-/**
- * @file timer.c
- * @author Lunaixsky
- * @brief A simple timer implementation based on APIC with adjustable frequency and subscribable "timerlets"
- * @version 0.1
- * @date 2022-03-12
- *
- * @copyright Copyright (c) 2022
- *
- */
-#include <arch/x86/interrupts.h>
-#include <hal/apic.h>
-#include <hal/rtc.h>
-
-#include <lunaix/mm/kalloc.h>
-#include <lunaix/spike.h>
-#include <lunaix/syslog.h>
-#include <lunaix/time.h>
-#include <lunaix/timer.h>
-
-#define LVT_ENTRY_TIMER(vector, mode) (LVT_DELIVERY_FIXED | mode | vector)
-
-
-LOG_MODULE("TIMER");
-
-static void
-temp_intr_routine_rtc_tick(const isr_param* param);
-
-static void
-temp_intr_routine_apic_timer(const isr_param* param);
-
-static void
-timer_update(const isr_param* param);
-
-static volatile struct lx_timer_context* timer_ctx;
-
-// Don't optimize them! Took me an half hour to figure that out...
-
-static volatile uint32_t rtc_counter = 0;
-static volatile uint8_t apic_timer_done = 0;
-
-#define APIC_CALIBRATION_CONST 0x100000
-
-void
-timer_init_context()
-{
- timer_ctx =
- (struct lx_timer_context*)lxmalloc(sizeof(struct lx_timer_context));
-
- assert_msg(timer_ctx, "Fail to initialize timer contex");
-
- timer_ctx->active_timers =
- (struct lx_timer*)lxmalloc(sizeof(struct lx_timer));
- llist_init_head(timer_ctx->active_timers);
-}
-
-void
-timer_init(uint32_t frequency)
-{
- timer_init_context();
-
- cpu_disable_interrupt();
-
- // Setup APIC timer
-
- // Setup a one-shot timer, we will use this to measure the bus speed. So we
- // can
- // then calibrate apic timer to work at *nearly* accurate hz
- apic_write_reg(APIC_TIMER_LVT,
- LVT_ENTRY_TIMER(APIC_TIMER_IV, LVT_TIMER_ONESHOT));
-
- // Set divider to 64
- apic_write_reg(APIC_TIMER_DCR, APIC_TIMER_DIV64);
-
- /*
- Timer calibration process - measure the APIC timer base frequency
-
- step 1: setup a temporary isr for RTC timer which trigger at each tick
- (1024Hz)
- step 2: setup a temporary isr for #APIC_TIMER_IV
- step 3: setup the divider, APIC_TIMER_DCR
- step 4: Startup RTC timer
- step 5: Write a large value, v, to APIC_TIMER_ICR to start APIC timer (this must be
- followed immediately after step 4)
- step 6: issue a write to EOI and clean up.
-
- When the APIC ICR counting down to 0 #APIC_TIMER_IV triggered, save the
- rtc timer's counter, k, and disable RTC timer immediately (although the
- RTC interrupts should be blocked by local APIC as we are currently busy
- on handling #APIC_TIMER_IV)
-
- So the apic timer frequency F_apic in Hz can be calculate as
- v / F_apic = k / 1024
- => F_apic = v / k * 1024
-
- */
-
- timer_ctx->base_frequency = 0;
- rtc_counter = 0;
- apic_timer_done = 0;
-
- intr_subscribe(APIC_TIMER_IV, temp_intr_routine_apic_timer);
- intr_subscribe(RTC_TIMER_IV, temp_intr_routine_rtc_tick);
-
- rtc_enable_timer(); // start RTC timer
- apic_write_reg(APIC_TIMER_ICR, APIC_CALIBRATION_CONST); // start APIC timer
-
- // enable interrupt, just for our RTC start ticking!
- cpu_enable_interrupt();
-
- wait_until(apic_timer_done);
-
- // cpu_disable_interrupt();
-
- assert_msg(timer_ctx->base_frequency, "Fail to initialize timer (NOFREQ)");
-
- kprintf(KINFO "Base frequency: %u Hz\n", timer_ctx->base_frequency);
-
- timer_ctx->running_frequency = frequency;
- timer_ctx->tick_interval = timer_ctx->base_frequency / frequency;
-
- // cleanup
- intr_unsubscribe(APIC_TIMER_IV, temp_intr_routine_apic_timer);
- intr_unsubscribe(RTC_TIMER_IV, temp_intr_routine_rtc_tick);
-
- apic_write_reg(APIC_TIMER_LVT,
- LVT_ENTRY_TIMER(APIC_TIMER_IV, LVT_TIMER_PERIODIC));
- intr_subscribe(APIC_TIMER_IV, timer_update);
-
- apic_write_reg(APIC_TIMER_ICR, timer_ctx->tick_interval);
-}
-
-int
-timer_run_second(uint32_t second, void (*callback)(void*), void* payload, uint8_t flags)
-{
- return timer_run(second * timer_ctx->running_frequency, callback, payload, flags);
-}
-
-int
-timer_run(uint32_t ticks, void (*callback)(void*), void* payload, uint8_t flags)
-{
- struct lx_timer* timer = (struct lx_timer*)lxmalloc(sizeof(struct lx_timer));
-
- if (!timer) return 0;
-
- timer->callback = callback;
- timer->counter = ticks;
- timer->deadline = ticks;
- timer->payload = payload;
- timer->flags = flags;
-
- llist_append(timer_ctx->active_timers, &timer->link);
-
- return 1;
-}
-
-static void
-timer_update(const isr_param* param)
-{
- struct lx_timer *pos, *n;
- struct lx_timer* timer_list_head = timer_ctx->active_timers;
-
- llist_for_each(pos, n, &timer_list_head->link, link)
- {
- if (--pos->counter) {
- continue;
- }
-
- pos->callback ? pos->callback(pos->payload) : 1;
-
- if (pos->flags & TIMER_MODE_PERIODIC) {
- pos->counter = pos->deadline;
- } else {
- llist_delete(&pos->link);
- lxfree(pos);
- }
- }
-}
-
-static void
-temp_intr_routine_rtc_tick(const isr_param* param)
-{
- rtc_counter++;
-
- // dummy read on register C so RTC can send anther interrupt
- // This strange behaviour observed in virtual box & bochs
- (void)rtc_read_reg(RTC_REG_C);
-}
-
-static void
-temp_intr_routine_apic_timer(const isr_param* param)
-{
- timer_ctx->base_frequency =
- APIC_CALIBRATION_CONST / rtc_counter * RTC_TIMER_BASE_FREQUENCY;
- apic_timer_done = 1;
-
- rtc_disable_timer();
-}
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / blobdiff