#include "hwtimer.h"
#include "riscv-traps.h"
#include <stdint.h>
#include <stdio.h>
#include <tx_api.h>
#include <tx_port.h>

#if __riscv_xlen == 64
#define INTERRUPT_BIT 0x8000000000000000ull
#else
#define INTERRUPT_BIT 0x80000000ull
#endif
#define OS_IS_INTERRUPT(mcause) (mcause & INTERRUPT_BIT)
#define OS_IS_TICK_INT(mcause) (mcause == (0x7 | INTERRUPT_BIT))
#define OS_IS_SOFT_INT(mcause) (mcause == (0x3 | INTERRUPT_BIT))
#define OS_IS_EXT_INT(mcause) (mcause == (0xb | INTERRUPT_BIT))

extern void _tx_timer_interrupt(void);
extern uintptr_t exception(uintptr_t mcause, uintptr_t mepc, uintptr_t mtval);

void (*irq_handler[__riscv_xlen])();

int register_irq_handler(unsigned irq_num, void (*handler)()) {
    if(irq_num<__riscv_xlen){
        irq_handler[irq_num] = handler;
        return 1;
    }
    return 0;
}

void trap_handler(uintptr_t mcause, uintptr_t mepc, uintptr_t mtval) {
    if(OS_IS_INTERRUPT(mcause)) {
        unsigned irq_id = mcause&(__riscv_xlen-1);
        switch(irq_id){
            case RISCV_INT_MTI:
#ifdef NX_DEBUG
                printf("Timer interrupt being handled (pc=%lx)\n", mepc);
#endif
                hwtimer_handler();
                _tx_timer_interrupt();
                break;
            case RISCV_INT_MEI:
                puts("[INTERRUPT]: handler ext irq error!\n");
                while(1)
                    ;
                break;
            default:
                if(irq_handler[irq_id])
                    irq_handler[irq_id]();
                else {
                    printf("[INTERRUPT]: Unkown Interrupt %d!!\n", mcause&0xff);
                    puts("[INTERRUPT]: now can't deal with the interrupt!\n");
                    while(1)
                        ;
                }
        }
    } else {
        exception( mcause,  mepc,  mtval);
    }
}