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/* defines for inline arch setup functions */

#include <asm/apic.h>

/**
 * do_timer_interrupt_hook - hook into timer tick
 * @regs:       standard registers from interrupt
 *
 * Description:
 *      This hook is called immediately after the timer interrupt is ack'd.
 *      It's primary purpose is to allow architectures that don't possess
 *      individual per CPU clocks (like the CPU APICs supply) to broadcast the
 *      timer interrupt as a means of triggering reschedules etc.
 **/

static inline void do_timer_interrupt_hook(struct pt_regs *regs)
{
        do_timer(regs);
/*
 * In the SMP case we use the local APIC timer interrupt to do the
 * profiling, except when we simulate SMP mode on a uniprocessor
 * system, in that case we have to call the local interrupt handler.
 */
#ifndef CONFIG_X86_LOCAL_APIC
        x86_do_profile(regs);
#else
        if (!using_apic_timer)
                smp_local_timer_interrupt(regs);
#endif
}


/* you can safely undefine this if you don't have the Neptune chipset */

#define BUGGY_NEPTUN_TIMER

/**
 * do_timer_overflow - process a detected timer overflow condition
 * @count:      hardware timer interrupt count on overflow
 *
 * Description:
 *      This call is invoked when the jiffies count has not incremented but
 *      the hardware timer interrupt has.  It means that a timer tick interrupt
 *      came along while the previous one was pending, thus a tick was missed
 **/
static inline int do_timer_overflow(int count)
{
        int i;

        spin_lock(&i8259A_lock);
        /*
         * This is tricky when I/O APICs are used;
         * see do_timer_interrupt().
         */
        i = inb(0x00);
        spin_unlock(&i8259A_lock);
       
        /* assumption about timer being IRQ0 */
        if (i & 0x01) {
                /*
                 * We cannot detect lost timer interrupts ...
                 * well, that's why we call them lost, don't we? :)
                 * [hmm, on the Pentium and Alpha we can ... sort of]
                 */
                count -= LATCH;
        } else {
#ifdef BUGGY_NEPTUN_TIMER
                /*
                 * for the Neptun bug we know that the 'latch'
                 * command doesn't latch the high and low value
                 * of the counter atomically. Thus we have to
                 * substract 256 from the counter
                 * ... funny, isnt it? :)
                 */
               
                count -= 256;
#else
                printk("do_slow_gettimeoffset(): hardware timer problem?\n");
#endif
        }
        return count;
}