#include <arch/acpi/local_apic.hpp>
#include <arch/acpi.h>
#include <socks/vm.h>
#include <socks/compiler.h>

#define LAPIC_REG_EOI 0xB0

namespace arch::acpi {
static local_apic lapic;

local_apic::local_apic(uint32_t *base) : base_(base)
{
}

kern_status_t local_apic::find(struct acpi_madt *madt, local_apic& out)
{
	phys_addr_t local_apic = madt->m_lapic_ptr;

	unsigned char *p = (unsigned char *)madt + sizeof *madt;
	unsigned char *madt_end = (unsigned char *)madt + madt->m_base.s_length;

	while (p < madt_end) {
		struct acpi_madt_record *rec = (struct acpi_madt_record *)p;
		struct lapic_override_record *lapic;

		switch (rec->r_type) {
		case ACPI_MADT_LAPIC_OVERRIDE:
			lapic = (struct lapic_override_record *)(rec + 1);
			out.base_ = (uint32_t *)vm_phys_to_virt(lapic->l_lapic_ptr);
			return KERN_OK;
		default:
			break;
		}

		p += rec->r_length;
	}

	out.base_ = (uint32_t *)vm_phys_to_virt(local_apic);
	return KERN_OK;
}

uint32_t local_apic::read(uint32_t reg)
{
	return read_once(base_ + (reg >> 2));
}

void local_apic::write(uint32_t reg, uint32_t val)
{
	write_once(base_ + (reg >> 2), val);
}

void local_apic::ack()
{
	write(LAPIC_REG_EOI, 0);
}

void local_apic::send_ipi(unsigned int dest, unsigned int data)
{
	uint32_t dest_val = (read(IPI_DEST) & 0x00FFFFFF) | (dest << 24);
	write(IPI_STATUS, 0);
	write(IPI_DEST, dest_val);

	uint32_t icr_val = (read(IPI_ICR) & 0xFFF00000) | data;
	write(IPI_ICR, icr_val);

	do {
		__asm__ __volatile__("pause" : : : "memory");
	} while (read(IPI_ICR) & (1 << 12));
}

local_apic& local_apic::get(void)
{
	return lapic;
}
}