static void sun4u_irq_enable(unsigned int virt_irq)
 {
-       irq_desc_t *desc = irq_desc + virt_irq;
-       struct irq_handler_data *data = desc->handler_data;
+       struct irq_handler_data *data = get_irq_chip_data(virt_irq);
 
        if (likely(data)) {
                unsigned long cpuid, imap;
 
 static void sun4u_irq_disable(unsigned int virt_irq)
 {
-       irq_desc_t *desc = irq_desc + virt_irq;
-       struct irq_handler_data *data = desc->handler_data;
+       struct irq_handler_data *data = get_irq_chip_data(virt_irq);
 
        if (likely(data)) {
                unsigned long imap = data->imap;
 
 static void sun4u_irq_end(unsigned int virt_irq)
 {
-       irq_desc_t *desc = irq_desc + virt_irq;
-       struct irq_handler_data *data = desc->handler_data;
+       struct irq_handler_data *data = get_irq_chip_data(virt_irq);
 
        if (likely(data))
                upa_writel(ICLR_IDLE, data->iclr);
 static void run_pre_handler(unsigned int virt_irq)
 {
        struct ino_bucket *bucket = virt_irq_to_bucket(virt_irq);
-       irq_desc_t *desc = irq_desc + virt_irq;
-       struct irq_handler_data *data = desc->handler_data;
+       struct irq_handler_data *data = get_irq_chip_data(virt_irq);
 
        if (likely(data->pre_handler)) {
                data->pre_handler(__irq_ino(__irq(bucket)),
                             void (*func)(unsigned int, void *, void *),
                             void *arg1, void *arg2)
 {
-       irq_desc_t *desc = irq_desc + virt_irq;
-       struct irq_handler_data *data = desc->handler_data;
+       struct irq_handler_data *data = get_irq_chip_data(virt_irq);
+       struct irq_chip *chip;
 
        data->pre_handler = func;
        data->pre_handler_arg1 = arg1;
        data->pre_handler_arg2 = arg2;
 
-       if (desc->chip == &sun4u_irq_ack ||
-           desc->chip == &sun4v_irq_ack)
+       chip = get_irq_chip(virt_irq);
+       if (chip == &sun4u_irq_ack ||
+           chip == &sun4v_irq_ack)
                return;
 
-       desc->chip = (desc->chip == &sun4u_irq ?
-                     &sun4u_irq_ack : &sun4v_irq_ack);
+       chip = (chip == &sun4u_irq ?
+               &sun4u_irq_ack : &sun4v_irq_ack);
+       set_irq_chip(virt_irq, chip);
 }
 
 unsigned int build_irq(int inofixup, unsigned long iclr, unsigned long imap)
 {
        struct ino_bucket *bucket;
        struct irq_handler_data *data;
-       irq_desc_t *desc;
        int ino;
 
        BUG_ON(tlb_type == hypervisor);
        bucket = &ivector_table[ino];
        if (!bucket->virt_irq) {
                bucket->virt_irq = virt_irq_alloc(__irq(bucket));
-               irq_desc[bucket->virt_irq].chip = &sun4u_irq;
+               set_irq_chip(bucket->virt_irq, &sun4u_irq);
        }
 
-       desc = irq_desc + bucket->virt_irq;
-       if (unlikely(desc->handler_data))
+       data = get_irq_chip_data(bucket->virt_irq);
+       if (unlikely(data))
                goto out;
 
        data = kzalloc(sizeof(struct irq_handler_data), GFP_ATOMIC);
                prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
                prom_halt();
        }
-       desc->handler_data = data;
+       set_irq_chip_data(bucket->virt_irq, data);
 
        data->imap  = imap;
        data->iclr  = iclr;
        struct ino_bucket *bucket;
        struct irq_handler_data *data;
        unsigned long sysino;
-       irq_desc_t *desc;
 
        BUG_ON(tlb_type != hypervisor);
 
        bucket = &ivector_table[sysino];
        if (!bucket->virt_irq) {
                bucket->virt_irq = virt_irq_alloc(__irq(bucket));
-               irq_desc[bucket->virt_irq].chip = &sun4v_irq;
+               set_irq_chip(bucket->virt_irq, &sun4v_irq);
        }
 
-       desc = irq_desc + bucket->virt_irq;
-       if (unlikely(desc->handler_data))
+       data = get_irq_chip_data(bucket->virt_irq);
+       if (unlikely(data))
                goto out;
 
        data = kzalloc(sizeof(struct irq_handler_data), GFP_ATOMIC);
                prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
                prom_halt();
        }
-       desc->handler_data = data;
+       set_irq_chip_data(bucket->virt_irq, data);
 
        /* Catch accidental accesses to these things.  IMAP/ICLR handling
         * is done by hypervisor calls on sun4v platforms, not by direct