#include <arch/gdt.h>
#include <arch/tss.h>
#include <kernel/libc/string.h>

static void tss_flush(int index)
{
	index *= sizeof(struct gdt_entry);
	index |= 3;
	asm volatile("mov %0, %%eax; ltr %%ax" ::"r"(index));
}

void tss_init(struct tss *tss, struct tss_ptr *ptr)
{
	memset(tss, 0x0, sizeof *tss);

	ptr->tss_base = (uint64_t)tss;
	ptr->tss_limit = (uint16_t)sizeof *tss;
}

void tss_load(struct tss *tss)
{
	tss_flush(TSS_GDT_INDEX);
}

virt_addr_t tss_get_kstack(struct tss *tss)
{
	return tss->rsp0;
}

virt_addr_t tss_get_ustack(struct tss *tss)
{
	return tss->rsp2;
}

void tss_set_kstack(struct tss *tss, virt_addr_t sp)
{
	tss->rsp0 = sp;
}

void tss_set_ustack(struct tss *tss, virt_addr_t sp)
{
	tss->rsp2 = sp;
}