isr.c

#include "types.h"
#include "printk.h"
#include "macro.h"
#include "serial.h"
#include "ports.h"
#include "isr.h"

#define NUM_INTERRUPT_HANDLERS 256

/* If I make these static gcc gets mad because they arn't used localy */
void isr_handler(struct registers);
void irq_handler(struct registers);

static isr_t interrupt_handlers[NUM_INTERRUPT_HANDLERS] = { NULL };

/**
 * ISR handlers
 */
void
isr_handler(struct registers regs)
{
    isr_t handler;
    
    if (regs.int_no > ELEMENTS_OF(interrupt_handlers))
        die("ISR: %d bigger than interrupt handlers array\n", regs.int_no);
    
    handler = interrupt_handlers[regs.int_no];
    if (handler == NULL) 
        die("ISR: %d No handler for event\n", regs.int_no);

    handler(&regs);
}

/**
 * IRQ Handler
 */
void
irq_handler(struct registers regs)
{
    isr_t handler;

    if (regs.int_no >= 40) 
        outb(0xA0, 0x20); // Send reset signal to slave
    
    // Send reset signal to master
    outb(0x20, 0x20);

    if (regs.int_no > ELEMENTS_OF(interrupt_handlers))
        die("IRQ: %d bigger than possible handler\n", regs.int_no);

    handler = interrupt_handlers[regs.int_no];
    if (handler == NULL)
        die("IRQ: %d No handler for event\n", regs.int_no);
    
    handler(&regs);
}

/**
 * Register an interrupt handler
 */
void
register_interrupt_handler(uint16_t n, isr_t handler)
{
    if (handler == NULL)
        die("Attempting to register NULL handler\n");

    if (n >= ELEMENTS_OF(interrupt_handlers))
        die("Attempting to register handler bigger than array\n");

    printk(INFO, "Registering handler %d\n", n);
    interrupt_handlers[n] = handler;
}