int irq_select_affinity(unsigned int irq)
 {
+       struct irq_desc *desc = irq_to_desc[irq];
        static int last_cpu;
        int cpu = last_cpu + 1;
 
-       if (!irq_desc[irq].chip->set_affinity || irq_user_affinity[irq])
+       if (!desc || !get_irq_desc_chip(desc)->set_affinity || irq_user_affinity[irq])
                return 1;
 
        while (!cpu_possible(cpu) ||
                cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
        last_cpu = cpu;
 
-       cpumask_copy(irq_desc[irq].affinity, cpumask_of(cpu));
-       irq_desc[irq].chip->set_affinity(irq, cpumask_of(cpu));
+       cpumask_copy(desc->affinity, cpumask_of(cpu));
+       get_irq_desc_chip(desc)->set_affinity(irq, cpumask_of(cpu));
        return 0;
 }
 #endif /* CONFIG_SMP */
        int j;
        int irq = *(loff_t *) v;
        struct irqaction * action;
+       struct irq_desc *desc;
        unsigned long flags;
 
 #ifdef CONFIG_SMP
 #endif
 
        if (irq < ACTUAL_NR_IRQS) {
-               raw_spin_lock_irqsave(&irq_desc[irq].lock, flags);
-               action = irq_desc[irq].action;
+               desc = irq_to_desc(irq);
+
+               if (!desc)
+                       return 0;
+
+               raw_spin_lock_irqsave(&desc->lock, flags);
+               action = desc->action;
                if (!action) 
                        goto unlock;
                seq_printf(p, "%3d: ", irq);
                for_each_online_cpu(j)
                        seq_printf(p, "%10u ", kstat_irqs_cpu(irq, j));
 #endif
-               seq_printf(p, " %14s", irq_desc[irq].chip->name);
+               seq_printf(p, " %14s", get_irq_desc_chip(desc)->name);
                seq_printf(p, "  %c%s",
                        (action->flags & IRQF_DISABLED)?'+':' ',
                        action->name);
 
                seq_putc(p, '\n');
 unlock:
-               raw_spin_unlock_irqrestore(&irq_desc[irq].lock, flags);
+               raw_spin_unlock_irqrestore(&desc->lock, flags);
        } else if (irq == ACTUAL_NR_IRQS) {
 #ifdef CONFIG_SMP
                seq_puts(p, "IPI: ");
         * handled by some other CPU. (or is disabled)
         */
        static unsigned int illegal_count=0;
+       struct irq_desc *desc = irq_to_desc(irq);
        
-       if ((unsigned) irq > ACTUAL_NR_IRQS && illegal_count < MAX_ILLEGAL_IRQS ) {
+       if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS &&
+           illegal_count < MAX_ILLEGAL_IRQS)) {
                irq_err_count++;
                illegal_count++;
                printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
         * at IPL 0.
         */
        local_irq_disable();
-       generic_handle_irq(irq);
+       generic_handle_irq_desc(irq, desc);
        irq_exit();
 }
 
 
 void __init
 init_rtc_irq(void)
 {
-       irq_desc[RTC_IRQ].status = IRQ_DISABLED;
-       irq_desc[RTC_IRQ].chip = &rtc_irq_type;
-       setup_irq(RTC_IRQ, &timer_irqaction);
+       struct irq_desc *desc = irq_to_desc(RTC_IRQ);
+
+       if (desc) {
+               desc->status |= IRQ_DISABLED;
+               set_irq_chip(RTC_IRQ, &rtc_irq_type);
+               setup_irq(RTC_IRQ, &timer_irqaction);
+       }
 }
 
 /* Dummy irqactions.  */
 
 void
 i8259a_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       struct irq_desc *desc = irq_to_desc(irq);
+       if (desc || !(desc->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                i8259a_enable_irq(irq);
 }
 
 
 static void
 pyxis_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       struct irq_desc *desc = irq_to_desc(irq);
+       if (desc || !(desc->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                pyxis_enable_irq(irq);
 }
 
                if ((ignore_mask >> i) & 1)
                        continue;
                set_irq_chip_and_handler(i, &pyxis_irq_type, alpha_do_IRQ);
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
        }
 
        setup_irq(16+7, &isa_cascade_irqaction);
 
 static void
 srm_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                srm_enable_irq(irq);
 }
 
        for (i = 16; i < max; ++i) {
                if (i < 64 && ((ignore_mask >> i) & 1))
                        continue;
-               irq_desc[i].status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &srm_irq_type, alpha_do_IRQ);
+               irq_to_desc(i)->status |= IRQ_LEVEL;
        }
 }
 
 
 static void
 alcor_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                alcor_enable_irq(irq);
 }
 
                   on while IRQ probing.  */
                if (i >= 16+20 && i <= 16+30)
                        continue;
-               irq_desc[i].status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &alcor_irq_type, alpha_do_IRQ);
+               irq_to_desc(i)->status |= IRQ_LEVEL;
        }
        i8259a_irq_type.ack = alcor_isa_mask_and_ack_irq;
 
 
 static void
 cabriolet_end_irq(unsigned int irq)
 { 
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                cabriolet_enable_irq(irq);
 }
 
                for (i = 16; i < 35; ++i) {
                        set_irq_chip_and_handler(i, &cabriolet_irq_type,
                                alpha_do_IRQ);
-                       irq_desc[i].status |= IRQ_LEVEL;
+                       irq_to_desc(i)->status |= IRQ_LEVEL;
                }
        }
 
 
 static void
 dp264_end_irq(unsigned int irq)
 { 
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                dp264_enable_irq(irq);
 }
 
 static void
 clipper_end_irq(unsigned int irq)
 { 
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                clipper_enable_irq(irq);
 }
 
 {
        long i;
        for (i = imin; i <= imax; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, ops, alpha_do_IRQ);
        }
 }
 
 static void
 eb64p_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                eb64p_enable_irq(irq);
 }
 
        init_i8259a_irqs();
 
        for (i = 16; i < 32; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &eb64p_irq_type, alpha_do_IRQ);
        }               
 
 
 static void
 eiger_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                eiger_enable_irq(irq);
 }
 
        init_i8259a_irqs();
 
        for (i = 16; i < 128; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &eiger_irq_type, alpha_do_IRQ);
        }
 }
 
        /* the parport is really hw IRQ 1, silly Jensen.  */
        if (irq == 7)
                i8259a_startup_irq(1);
-       else
-               /*
-                * For all true local interrupts, set the flag that prevents
-                * the IPL from being dropped during handler processing.
-                */
-               if (irq_desc[irq].action)
-                       irq_desc[irq].action->flags |= IRQF_DISABLED;
+
        return 0;
 }
 
        }
 
        /* If there is no handler yet... */
-       if (irq_desc[irq].action == NULL) {
+       if (!irq_has_action(irq)) {
            /* If it is a local interrupt that cannot be masked... */
            if (vector >= 0x900)
            {
 
 static void
 io7_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                io7_enable_irq(irq);
 }
 
 
        /* Set up the lsi irqs.  */
        for (i = 0; i < 128; ++i) {
-               irq_desc[base + i].status |= IRQ_LEVEL;
+               irq_to_desc(base + i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(base + i, lsi_ops, alpha_do_IRQ);
        }
 
 
        /* Set up the msi irqs.  */
        for (i = 128; i < (128 + 512); ++i) {
-               irq_desc[base + i].status |= IRQ_LEVEL;
+               irq_to_desc(base + i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(base + i, msi_ops, alpha_do_IRQ);
        }
 
 
 static void
 mikasa_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                mikasa_enable_irq(irq);
 }
 
        mikasa_update_irq_hw(0);
 
        for (i = 16; i < 32; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &mikasa_irq_type, alpha_do_IRQ);
        }
 
 
 static void
 noritake_end_irq(unsigned int irq)
 {
-        if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+        if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                 noritake_enable_irq(irq);
 }
 
        outw(0, 0x54c);
 
        for (i = 16; i < 48; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &noritake_irq_type, alpha_do_IRQ);
        }
 
 
 static void
 rawhide_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                rawhide_enable_irq(irq);
 }
 
        }
 
        for (i = 16; i < 128; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &rawhide_irq_type, alpha_do_IRQ);
        }
 
 
 static void
 rx164_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                rx164_enable_irq(irq);
 }
 
 
        rx164_update_irq_hw(0);
        for (i = 16; i < 40; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &rx164_irq_type, alpha_do_IRQ);
        }
 
 
 static void
 sable_lynx_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                sable_lynx_enable_irq(irq);
 }
 
        long i;
 
        for (i = 0; i < nr_of_irqs; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &sable_lynx_irq_type,
                        alpha_do_IRQ);
        }
 
 static void
 takara_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                takara_enable_irq(irq);
 }
 
                takara_update_irq_hw(i, -1);
 
        for (i = 16; i < 128; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, &takara_irq_type, alpha_do_IRQ);
        }
 
 
 static void
 titan_end_irq(unsigned int irq)
 {
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                titan_enable_irq(irq);
 }
 
 {
        long i;
        for (i = imin; i <= imax; ++i) {
-               irq_desc[i].status |= IRQ_LEVEL;
+               irq_to_desc(i)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i, ops, alpha_do_IRQ);
        }
 }
 
 wildfire_end_irq(unsigned int irq)
 { 
 #if 0
-       if (!irq_desc[irq].action)
+       if (!irq_has_action(irq))
                printk("got irq %d\n", irq);
 #endif
-       if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+       if (!(irq_to_desc(irq)->status & (IRQ_DISABLED|IRQ_INPROGRESS)))
                wildfire_enable_irq(irq);
 }
 
        for (i = 0; i < 16; ++i) {
                if (i == 2)
                        continue;
-               irq_desc[i+irq_bias].status |= IRQ_LEVEL;
+               irq_to_desc(i+irq_bias)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i+irq_bias, &wildfire_irq_type,
                        alpha_do_IRQ);
        }
 
-       irq_desc[36+irq_bias].status |= IRQ_LEVEL;
+       irq_to_desc(36+irq_bias)->status |= IRQ_LEVEL;
        set_irq_chip_and_handler(36+irq_bias, &wildfire_irq_type, alpha_do_IRQ);
        for (i = 40; i < 64; ++i) {
-               irq_desc[i+irq_bias].status |= IRQ_LEVEL;
+               irq_to_desc(i+irq_bias)->status |= IRQ_LEVEL;
                set_irq_chip_and_handler(i+irq_bias, &wildfire_irq_type,
                        alpha_do_IRQ);
        }