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Rev 2071 Rev 2107
Line 66... Line 66...
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    return IRQ_ACCEPT;
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    return IRQ_ACCEPT;
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}
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}
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static void i8254_irq_handler(irq_t *irq, void *arg, ...)
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static void i8254_irq_handler(irq_t *irq, void *arg, ...)
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{
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{
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    /*
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     * This IRQ is responsible for kernel preemption.
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     * Nevertheless, we are now holding a spinlock which prevents
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     * preemption. For this particular IRQ, we don't need the
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     * lock. We just release it, call clock() and then reacquire it again.
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     */
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    spinlock_unlock(&irq->lock);
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    clock();
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    clock();
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    spinlock_lock(&irq->lock);
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}
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}
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void i8254_init(void)
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void i8254_init(void)
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{
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{
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    irq_initialize(&i8254_irq);
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    irq_initialize(&i8254_irq);
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    outb(CLK_PORT4, 0xd2);
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    outb(CLK_PORT4, 0xd2);
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    o2 = inb(CLK_PORT1);
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    o2 = inb(CLK_PORT1);
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    o2 |= inb(CLK_PORT1) << 8;
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    o2 |= inb(CLK_PORT1) << 8;
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- 
 
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    CPU->delay_loop_const =
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        ((MAGIC_NUMBER * LOOPS) / 1000) / ((t1 - t2) - (o1 - o2)) +
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    CPU->delay_loop_const = ((MAGIC_NUMBER*LOOPS)/1000) / ((t1-t2)-(o1-o2)) + (((MAGIC_NUMBER*LOOPS)/1000) % ((t1-t2)-(o1-o2)) ? 1 : 0);
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        (((MAGIC_NUMBER * LOOPS) / 1000) % ((t1 - t2) - (o1 - o2)) ? 1 : 0);
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    clk1 = get_cycle();
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    clk1 = get_cycle();
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    delay(1 << SHIFT);
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    delay(1 << SHIFT);
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    clk2 = get_cycle();
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    clk2 = get_cycle();
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