soaplin/kernel/src/dev/lapic.c

#include "mm/pmm.h"
#include <dev/lapic.h>
#include <sys/log.h>

uint64_t apic_ticks = 0;

void lapic_init() {
  lapic_write(0xf0, 0x1ff);
  log("lapic - initialized\n");
}

void lapic_stop_timer() {
  // We do this to avoid overlapping oneshots
  lapic_write(LAPIC_TIMER_INITCNT, 0);
  lapic_write(LAPIC_TIMER_LVT, LAPIC_TIMER_DISABLE);
}

void lapic_oneshot(uint8_t vec, uint64_t ms) {
  lapic_stop_timer();
  lapic_write(LAPIC_TIMER_DIV, 0);
  lapic_write(LAPIC_TIMER_LVT, vec);
  lapic_write(LAPIC_TIMER_INITCNT, apic_ticks * ms);
}

void lapic_calibrate_timer() {
  lapic_stop_timer();
  lapic_write(LAPIC_TIMER_DIV, 0);
  lapic_write(LAPIC_TIMER_LVT, (1 << 16) | 0xff);
  lapic_write(LAPIC_TIMER_INITCNT, 0xFFFFFFFF);
  //pit_sleep(1); // 1 ms
  lapic_write(LAPIC_TIMER_LVT, LAPIC_TIMER_DISABLE);
  uint32_t ticks = 0xFFFFFFFF - lapic_read(LAPIC_TIMER_CURCNT);
  apic_ticks = ticks;
  lapic_stop_timer();
}

void lapic_write(uint32_t reg, uint32_t val) {
  *((volatile uint32_t*)(HIGHER_HALF(0xfee00000) + reg)) = val;
}

uint32_t lapic_read(uint32_t reg) {
  return *((volatile uint32_t*)(HIGHER_HALF(0xfee00000) + reg));
}

void lapic_eoi() {
  lapic_write((uint8_t)0xb0, 0x0);
}

void lapic_ipi(uint32_t id, uint8_t dat) {
  lapic_write(LAPIC_ICRHI, id << LAPIC_ICDESTSHIFT);
  lapic_write(LAPIC_ICRLO, dat);
}

void lapic_send_all_int(uint32_t id, uint32_t vec) {
  lapic_ipi(id, vec | LAPIC_ICRAIS);
}

void lapic_send_others_int(uint32_t id, uint32_t vec) {
  lapic_ipi(id, vec | LAPIC_ICRAES);
}

uint32_t lapic_get_id() {
  return lapic_read(0x0020) >> LAPIC_ICDESTSHIFT;
}