/* Copyright (C) 2021,2022 fef <owo@fef.moe>.  All rights reserved. */

#include <arch/cpufunc.h>
#include <arch/interrupt.h>
#include <arch/port.h>
#include <arch/segment.h>
#include <arch/trap.h>

#include <gay/kprintf.h>
#include <gay/types.h>

struct x86_idt_entry x86_idt[X86_INTR_COUNT] __aligned(16);

void x86_setup_interrupts(void)
{
	/* make sure all IRQs are masked first */
	x86_outb(X86_PORT_PIC1_DATA, 0xff);
	x86_outb(X86_PORT_PIC2_DATA, 0xff);

	x86_set_trap_gate(X86_VECT_DE,	_x86_isr_divide_error);
	x86_set_trap_gate(X86_VECT_DB,	_x86_isr_debug_exception);
	x86_set_trap_gate(X86_VECT_NMI,	_x86_isr_nmi);
	x86_set_trap_gate(X86_VECT_BP,	_x86_isr_breakpoint);
	x86_set_trap_gate(X86_VECT_OF,	_x86_isr_overflow);
	x86_set_trap_gate(X86_VECT_BR,	_x86_isr_bound_range_exceeded);
	x86_set_trap_gate(X86_VECT_UD,	_x86_isr_invalid_opcode);
	x86_set_trap_gate(X86_VECT_NM,	_x86_isr_device_not_available);
	x86_set_trap_gate(X86_VECT_DF,	_x86_isr_double_fault);
	x86_set_trap_gate(X86_VECT_TS,	_x86_isr_invalid_tss);
	x86_set_trap_gate(X86_VECT_NP,	_x86_isr_segment_not_present);
	x86_set_trap_gate(X86_VECT_SS,	_x86_isr_stack_segment_fault);
	x86_set_trap_gate(X86_VECT_GP,	_x86_isr_general_protection);
	x86_set_trap_gate(X86_VECT_PF,	_x86_isr_page_fault);
	x86_set_trap_gate(X86_VECT_MF,	_x86_isr_x87_fpu_error);
	x86_set_trap_gate(X86_VECT_AC,	_x86_isr_alignment_check);
	x86_set_trap_gate(X86_VECT_MC,	_x86_isr_machine_check);
	x86_set_trap_gate(X86_VECT_XM,	_x86_isr_simd_floating_point_exception);
	x86_set_trap_gate(X86_VECT_VE,	_x86_isr_virtualization_exception);
	x86_set_trap_gate(X86_VECT_CP,	_x86_isr_control_protection_exception);

	x86_load_idt();
	enable_intr();
}

void x86_set_gate(u8 vector, void (*handler)(void), u8 flags)
{
	struct x86_idt_entry *entry = &x86_idt[vector];
#ifdef __x86_64__
	entry->selector = X86_64_KERN_CS;
#else
	entry->selector = X86_32_KERN_CS;
#endif
	entry->_rsvd0 = 0;
	entry->attr = flags;

	entry->offset0 = (uintptr_t)handler & 0xffff;
	entry->offset1 = ((uintptr_t)handler >> 16) & 0xffff;
#ifdef __x86_64__
	entry->offset2 = ((uintptr_t)handler >> 32) & 0xffffffff;
	entry->_rsvd1 = 0;
#endif
}

void x86_set_trap_gate(u8 vector, void (*isr)(void))
{
	u8 flags = X86_IDT_PRESENT | X86_IDT_GATE_TRAP32 | X86_IDT_DPL(0);
	if (vector < X86_VECT_IRQ_BASE)
		x86_set_gate(vector, isr, flags);
	else
		kprintf("Tried to assign non-trap vector %d to a trap gate\n", vector);
}

void x86_set_intr_gate(u8 vector, void (*isr)(void))
{
	u8 flags = X86_IDT_PRESENT | X86_IDT_GATE_INTR32 | X86_IDT_DPL(0);
	if (vector < X86_VECT_IRQ_BASE)
		kprintf("Tried to assign non-interrupt vector %d to an interrupt gate\n", vector);
	else
		x86_set_gate(vector, isr, flags);
}