/*
 * Copyright (c) 2011-2014 Richard Braun.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * Trap (interrupt and exception) handling.
 *
 * This file is a top header in the inclusion hierarchy, and shouldn't include
 * other headers that may cause circular dependencies.
 */

#ifndef X86_TRAP_H
#define X86_TRAP_H

#include <machine/page.h>

/*
 * Architecture defined traps.
 */
#define TRAP_DE                 0   /* Divide Error */
#define TRAP_DB                 1   /* Debug */
#define TRAP_NMI                2   /* NMI Interrupt */
#define TRAP_BP                 3   /* Breakpoint */
#define TRAP_OF                 4   /* Overflow */
#define TRAP_BR                 5   /* BOUND Range Exceeded */
#define TRAP_UD                 6   /* Invalid Opcode (Undefined Opcode) */
#define TRAP_NM                 7   /* Device Not Available (No Math Coprocessor) */
#define TRAP_DF                 8   /* Double Fault */
#define TRAP_TS                 10  /* Invalid TSS */
#define TRAP_NP                 11  /* Segment Not Present */
#define TRAP_SS                 12  /* Stack-Segment Fault */
#define TRAP_GP                 13  /* General Protection */
#define TRAP_PF                 14  /* Page Fault */
#define TRAP_MF                 16  /* x87 FPU Floating-Point Error (Math Fault) */
#define TRAP_AC                 17  /* Alignment Check */
#define TRAP_MC                 18  /* Machine Check */
#define TRAP_XM                 19  /* SIMD Floating-Point Exception */

/*
 * Traps used for handling external interrupts.
 */
#define TRAP_INTR_FIRST         32
#define TRAP_INTR_LAST          223

/*
 * System defined traps.
 *
 * The local APIC assigns one priority every 16 vectors.
 */
#define TRAP_XCALL              238
#define TRAP_THREAD_SCHEDULE    239
#define TRAP_CPU_HALT           240
#define TRAP_LAPIC_PMC_OF       252
#define TRAP_LAPIC_TIMER        253
#define TRAP_LAPIC_ERROR        254
#define TRAP_LAPIC_SPURIOUS     255

#define TRAP_NR_VECTORS         256

#define TRAP_INTR_TABLE_SIZE    256

#define TRAP_STACK_SIZE PAGE_SIZE

#ifndef __ASSEMBLER__

#include <stdint.h>
#include <stdio.h>

#include <kern/init.h>
#include <kern/macros.h>

#ifdef __LP64__

struct trap_frame {
    uint64_t rax;
    uint64_t rbx;
    uint64_t rcx;
    uint64_t rdx;
    uint64_t rbp;
    uint64_t rsi;
    uint64_t rdi;
    uint64_t r8;
    uint64_t r9;
    uint64_t r10;
    uint64_t r11;
    uint64_t r12;
    uint64_t r13;
    uint64_t r14;
    uint64_t r15;
    uint64_t vector;
    uint64_t error;
    uint64_t rip;
    uint64_t cs;
    uint64_t rflags;
    uint64_t rsp;
    uint64_t ss;
} __packed;

#else /* __LP64__ */

struct trap_frame {
    uint32_t eax;
    uint32_t ebx;
    uint32_t ecx;
    uint32_t edx;
    uint32_t ebp;
    uint32_t esi;
    uint32_t edi;
    uint16_t ds;
    uint16_t es;
    uint16_t fs;
    uint16_t gs;
    uint32_t vector;
    uint32_t error;
    uint32_t eip;
    uint32_t cs;
    uint32_t eflags;
    uint32_t esp;       /* esp and ss are undefined if trapped in kernel */
    uint32_t ss;
} __packed;

#endif /* __LP64__ */

/*
 * Type for trap handler functions.
 */
typedef void (*trap_handler_fn_t)(struct trap_frame *);

static inline void
trap_trigger_double_fault(void)
{
    printf("trap: double fault test\n");
    asm volatile("movl $0xdead, %esp; push $0");
}

/*
 * Unified trap entry point.
 */
void trap_main(struct trap_frame *frame);

/*
 * Register a trap handler.
 */
void trap_register(unsigned int vector, trap_handler_fn_t handler_fn);

/*
 * Display the content of a trap frame.
 */
void trap_frame_show(struct trap_frame *frame);

/*
 * Display the call trace interrupted by the trap of the given frame.
 */
void trap_stack_show(struct trap_frame *frame);

/*
 * Return a pointer to the local interrupt stack.
 *
 * This function is called by the low level trap handling code.
 *
 * Return NULL if no stack switching is required.
 */
void * trap_get_interrupt_stack(const struct trap_frame *frame);

/*
 * This init operation provides :
 *  - initialization of all IDT entries and trap handlers
 *  - double fault exception support
 */
INIT_OP_DECLARE(trap_setup);

#endif /* __ASSEMBLER__ */

#endif /* X86_TRAP_H */