[POWERPC] Add new interrupt mapping core and change platforms to use it

This adds the new irq remapper core and removes the old one.  Because
there are some fundamental conflicts with the old code, like the value
of NO_IRQ which I'm now setting to 0 (as per discussions with Linus),
etc..., this commit also changes the relevant platform and driver code
over to use the new remapper (so as not to cause difficulties later
in bisecting).

This patch removes the old pre-parsing of the open firmware interrupt
tree along with all the bogus assumptions it made to try to renumber
interrupts according to the platform. This is all to be handled by the
new code now.

For the pSeries XICS interrupt controller, a single remapper host is
created for the whole machine regardless of how many interrupt
presentation and source controllers are found, and it's set to match
any device node that isn't a 8259.  That works fine on pSeries and
avoids having to deal with some of the complexities of split source
controllers vs. presentation controllers in the pSeries device trees.

The powerpc i8259 PIC driver now always requests the legacy interrupt
range. It also has the feature of being able to match any device node
(including NULL) if passed no device node as an input. That will help
porting over platforms with broken device-trees like Pegasos who don't
have a proper interrupt tree.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

10 files changed, 593 insertions, 659 deletions

diff --git a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
index e47d40ac6f39..97ddc02a3d42 100644
--- a/arch/powerpc/kernel/ibmebus.c
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -323,13 +323,11 @@ int ibmebus_request_irq(struct ibmebus_dev *dev,
                         unsigned long irq_flags, const char * devname,
                         void *dev_id)
 {
-        unsigned int irq = virt_irq_create_mapping(ist);
+        unsigned int irq = irq_create_mapping(NULL, ist, 0);
         
         if (irq == NO_IRQ)
                 return -EINVAL;
         
-        irq = irq_offset_up(irq);
-        
         return request_irq(irq, handler,
                            irq_flags, devname, dev_id);
 }
@@ -337,12 +335,9 @@ EXPORT_SYMBOL(ibmebus_request_irq);
 
 void ibmebus_free_irq(struct ibmebus_dev *dev, u32 ist, void *dev_id)
 {
-        unsigned int irq = virt_irq_create_mapping(ist);
+        unsigned int irq = irq_find_mapping(NULL, ist);
         
-        irq = irq_offset_up(irq);
         free_irq(irq, dev_id);
-        
-        return;
 }
 EXPORT_SYMBOL(ibmebus_free_irq);
 
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 91248559099a..05a700940f67 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -29,6 +29,8 @@
  * to reduce code space and undefined function references.
  */
 
+#undef DEBUG
+
 #include <linux/module.h>
 #include <linux/threads.h>
 #include <linux/kernel_stat.h>
@@ -46,7 +48,10 @@
 #include <linux/cpumask.h>
 #include <linux/profile.h>
 #include <linux/bitops.h>
-#include <linux/pci.h>
+#include <linux/list.h>
+#include <linux/radix-tree.h>
+#include <linux/mutex.h>
+#include <linux/bootmem.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -57,6 +62,7 @@
 #include <asm/prom.h>
 #include <asm/ptrace.h>
 #include <asm/machdep.h>
+#include <asm/udbg.h>
 #ifdef CONFIG_PPC_ISERIES
 #include <asm/paca.h>
 #endif
@@ -88,7 +94,6 @@ extern atomic_t ipi_sent;
 EXPORT_SYMBOL(irq_desc);
 
 int distribute_irqs = 1;
-u64 ppc64_interrupt_controller;
 #endif /* CONFIG_PPC64 */
 
 int show_interrupts(struct seq_file *p, void *v)
@@ -181,7 +186,7 @@ void fixup_irqs(cpumask_t map)
 
 void do_IRQ(struct pt_regs *regs)
 {
-        int irq;
+        unsigned int irq;
 #ifdef CONFIG_IRQSTACKS
         struct thread_info *curtp, *irqtp;
 #endif
@@ -212,7 +217,7 @@ void do_IRQ(struct pt_regs *regs)
          */
         irq = ppc_md.get_irq(regs);
 
-        if (irq >= 0) {
+        if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
 #ifdef CONFIG_IRQSTACKS
                 /* Switch to the irq stack to handle this */
                 curtp = current_thread_info();
@@ -231,7 +236,7 @@ void do_IRQ(struct pt_regs *regs)
                 } else
 #endif
                         generic_handle_irq(irq, regs);
-        } else if (irq != -2)
+        } else if (irq != NO_IRQ_IGNORE)
                 /* That's not SMP safe ... but who cares ? */
                 ppc_spurious_interrupts++;
 
@@ -254,123 +259,6 @@ void __init init_IRQ(void)
 #endif
 }
 
-#ifdef CONFIG_PPC64
-/*
- * Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
- */
-
-#define UNDEFINED_IRQ 0xffffffff
-unsigned int virt_irq_to_real_map[NR_IRQS];
-
-/*
- * Don't use virtual irqs 0, 1, 2 for devices.
- * The pcnet32 driver considers interrupt numbers < 2 to be invalid,
- * and 2 is the XICS IPI interrupt.
- * We limit virtual irqs to __irq_offet_value less than virt_irq_max so
- * that when we offset them we don't end up with an interrupt
- * number >= virt_irq_max.
- */
-#define MIN_VIRT_IRQ    3
-
-unsigned int virt_irq_max;
-static unsigned int max_virt_irq;
-static unsigned int nr_virt_irqs;
-
-void
-virt_irq_init(void)
-{
-        int i;
-
-        if ((virt_irq_max == 0) || (virt_irq_max > (NR_IRQS - 1)))
-                virt_irq_max = NR_IRQS - 1;
-        max_virt_irq = virt_irq_max - __irq_offset_value;
-        nr_virt_irqs = max_virt_irq - MIN_VIRT_IRQ + 1;
-
-        for (i = 0; i < NR_IRQS; i++)
-                virt_irq_to_real_map[i] = UNDEFINED_IRQ;
-}
-
-/* Create a mapping for a real_irq if it doesn't already exist.
- * Return the virtual irq as a convenience.
- */
-int virt_irq_create_mapping(unsigned int real_irq)
-{
-        unsigned int virq, first_virq;
-        static int warned;
-
-        if (ppc64_interrupt_controller == IC_OPEN_PIC)
-                return real_irq;        /* no mapping for openpic (for now) */
-
-        if (ppc64_interrupt_controller == IC_CELL_PIC)
-                return real_irq;        /* no mapping for iic either */
-
-        /* don't map interrupts < MIN_VIRT_IRQ */
-        if (real_irq < MIN_VIRT_IRQ) {
-                virt_irq_to_real_map[real_irq] = real_irq;
-                return real_irq;
-        }
-
-        /* map to a number between MIN_VIRT_IRQ and max_virt_irq */
-        virq = real_irq;
-        if (virq > max_virt_irq)
-                virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ;
-
-        /* search for this number or a free slot */
-        first_virq = virq;
-        while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
-                if (virt_irq_to_real_map[virq] == real_irq)
-                        return virq;
-                if (++virq > max_virt_irq)
-                        virq = MIN_VIRT_IRQ;
-                if (virq == first_virq)
-                        goto nospace;   /* oops, no free slots */
-        }
-
-        virt_irq_to_real_map[virq] = real_irq;
-        return virq;
-
- nospace:
-        if (!warned) {
-                printk(KERN_CRIT "Interrupt table is full\n");
-                printk(KERN_CRIT "Increase virt_irq_max (currently %d) "
-                       "in your kernel sources and rebuild.\n", virt_irq_max);
-                warned = 1;
-        }
-        return NO_IRQ;
-}
-
-/*
- * In most cases will get a hit on the very first slot checked in the
- * virt_irq_to_real_map.  Only when there are a large number of
- * IRQs will this be expensive.
- */
-unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
-{
-        unsigned int virq;
-        unsigned int first_virq;
-
-        virq = real_irq;
-
-        if (virq > max_virt_irq)
-                virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ;
-
-        first_virq = virq;
-
-        do {
-                if (virt_irq_to_real_map[virq] == real_irq)
-                        return virq;
-
-                virq++;
-
-                if (virq >= max_virt_irq)
-                        virq = 0;
-
-        } while (first_virq != virq);
-
-        return NO_IRQ;
-
-}
-#endif /* CONFIG_PPC64 */
 
 #ifdef CONFIG_IRQSTACKS
 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
@@ -430,6 +318,503 @@ void do_softirq(void)
 }
 EXPORT_SYMBOL(do_softirq);
 
+
+/*
+ * IRQ controller and virtual interrupts
+ */
+
+#ifdef CONFIG_PPC_MERGE
+
+static LIST_HEAD(irq_hosts);
+static spinlock_t irq_big_lock = SPIN_LOCK_UNLOCKED;
+
+struct irq_map_entry irq_map[NR_IRQS];
+static unsigned int irq_virq_count = NR_IRQS;
+static struct irq_host *irq_default_host;
+
+struct irq_host *irq_alloc_host(unsigned int revmap_type,
+                                unsigned int revmap_arg,
+                                struct irq_host_ops *ops,
+                                irq_hw_number_t inval_irq)
+{
+        struct irq_host *host;
+        unsigned int size = sizeof(struct irq_host);
+        unsigned int i;
+        unsigned int *rmap;
+        unsigned long flags;
+
+        /* Allocate structure and revmap table if using linear mapping */
+        if (revmap_type == IRQ_HOST_MAP_LINEAR)
+                size += revmap_arg * sizeof(unsigned int);
+        if (mem_init_done)
+                host = kzalloc(size, GFP_KERNEL);
+        else {
+                host = alloc_bootmem(size);
+                if (host)
+                        memset(host, 0, size);
+        }
+        if (host == NULL)
+                return NULL;
+
+        /* Fill structure */
+        host->revmap_type = revmap_type;
+        host->inval_irq = inval_irq;
+        host->ops = ops;
+
+        spin_lock_irqsave(&irq_big_lock, flags);
+
+        /* If it's a legacy controller, check for duplicates and
+         * mark it as allocated (we use irq 0 host pointer for that
+         */
+        if (revmap_type == IRQ_HOST_MAP_LEGACY) {
+                if (irq_map[0].host != NULL) {
+                        spin_unlock_irqrestore(&irq_big_lock, flags);
+                        /* If we are early boot, we can't free the structure,
+                         * too bad...
+                         * this will be fixed once slab is made available early
+                         * instead of the current cruft
+                         */
+                        if (mem_init_done)
+                                kfree(host);
+                        return NULL;
+                }
+                irq_map[0].host = host;
+        }
+
+        list_add(&host->link, &irq_hosts);
+        spin_unlock_irqrestore(&irq_big_lock, flags);
+
+        /* Additional setups per revmap type */
+        switch(revmap_type) {
+        case IRQ_HOST_MAP_LEGACY:
+                /* 0 is always the invalid number for legacy */
+                host->inval_irq = 0;
+                /* setup us as the host for all legacy interrupts */
+                for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
+                        irq_map[i].hwirq = 0;
+                        smp_wmb();
+                        irq_map[i].host = host;
+                        smp_wmb();
+
+                        /* Clear some flags */
+                        get_irq_desc(i)->status
+                                &= ~(IRQ_NOREQUEST | IRQ_LEVEL);
+
+                        /* Legacy flags are left to default at this point,
+                         * one can then use irq_create_mapping() to
+                         * explicitely change them
+                         */
+                        ops->map(host, i, i, 0);
+                }
+                break;
+        case IRQ_HOST_MAP_LINEAR:
+                rmap = (unsigned int *)(host + 1);
+                for (i = 0; i < revmap_arg; i++)
+                        rmap[i] = IRQ_NONE;
+                host->revmap_data.linear.size = revmap_arg;
+                smp_wmb();
+                host->revmap_data.linear.revmap = rmap;
+                break;
+        default:
+                break;
+        }
+
+        pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
+
+        return host;
+}
+
+struct irq_host *irq_find_host(struct device_node *node)
+{
+        struct irq_host *h, *found = NULL;
+        unsigned long flags;
+
+        /* We might want to match the legacy controller last since
+         * it might potentially be set to match all interrupts in
+         * the absence of a device node. This isn't a problem so far
+         * yet though...
+         */
+        spin_lock_irqsave(&irq_big_lock, flags);
+        list_for_each_entry(h, &irq_hosts, link)
+                if (h->ops->match == NULL || h->ops->match(h, node)) {
+                        found = h;
+                        break;
+                }
+        spin_unlock_irqrestore(&irq_big_lock, flags);
+        return found;
+}
+EXPORT_SYMBOL_GPL(irq_find_host);
+
+void irq_set_default_host(struct irq_host *host)
+{
+        pr_debug("irq: Default host set to @0x%p\n", host);
+
+        irq_default_host = host;
+}
+
+void irq_set_virq_count(unsigned int count)
+{
+        pr_debug("irq: Trying to set virq count to %d\n", count);
+
+        BUG_ON(count < NUM_ISA_INTERRUPTS);
+        if (count < NR_IRQS)
+                irq_virq_count = count;
+}
+
+unsigned int irq_create_mapping(struct irq_host *host,
+                                irq_hw_number_t hwirq,
+                                unsigned int flags)
+{
+        unsigned int virq, hint;
+
+        pr_debug("irq: irq_create_mapping(0x%p, 0x%lx, 0x%x)\n",
+                 host, hwirq, flags);
+
+        /* Look for default host if nececssary */
+        if (host == NULL)
+                host = irq_default_host;
+        if (host == NULL) {
+                printk(KERN_WARNING "irq_create_mapping called for"
+                       " NULL host, hwirq=%lx\n", hwirq);
+                WARN_ON(1);
+                return NO_IRQ;
+        }
+        pr_debug("irq: -> using host @%p\n", host);
+
+        /* Check if mapping already exist, if it does, call
+         * host->ops->map() to update the flags
+         */
+        virq = irq_find_mapping(host, hwirq);
+        if (virq != IRQ_NONE) {
+                pr_debug("irq: -> existing mapping on virq %d\n", virq);
+                host->ops->map(host, virq, hwirq, flags);
+                return virq;
+        }
+
+        /* Get a virtual interrupt number */
+        if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
+                /* Handle legacy */
+                virq = (unsigned int)hwirq;
+                if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
+                        return NO_IRQ;
+                return virq;
+        } else {
+                /* Allocate a virtual interrupt number */
+                hint = hwirq % irq_virq_count;
+                virq = irq_alloc_virt(host, 1, hint);
+                if (virq == NO_IRQ) {
+                        pr_debug("irq: -> virq allocation failed\n");
+                        return NO_IRQ;
+                }
+        }
+        pr_debug("irq: -> obtained virq %d\n", virq);
+
+        /* Clear some flags */
+        get_irq_desc(virq)->status &= ~(IRQ_NOREQUEST | IRQ_LEVEL);
+
+        /* map it */
+        if (host->ops->map(host, virq, hwirq, flags)) {
+                pr_debug("irq: -> mapping failed, freeing\n");
+                irq_free_virt(virq, 1);
+                return NO_IRQ;
+        }
+        smp_wmb();
+        irq_map[virq].hwirq = hwirq;
+        smp_mb();
+        return virq;
+}
+EXPORT_SYMBOL_GPL(irq_create_mapping);
+
+extern unsigned int irq_create_of_mapping(struct device_node *controller,
+                                          u32 *intspec, unsigned int intsize)
+{
+        struct irq_host *host;
+        irq_hw_number_t hwirq;
+        unsigned int flags = IRQ_TYPE_NONE;
+
+        if (controller == NULL)
+                host = irq_default_host;
+        else
+                host = irq_find_host(controller);
+        if (host == NULL)
+                return NO_IRQ;
+
+        /* If host has no translation, then we assume interrupt line */
+        if (host->ops->xlate == NULL)
+                hwirq = intspec[0];
+        else {
+                if (host->ops->xlate(host, controller, intspec, intsize,
+                                     &hwirq, &flags))
+                        return NO_IRQ;
+        }
+
+        return irq_create_mapping(host, hwirq, flags);
+}
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
+
+unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
+{
+        struct of_irq oirq;
+
+        if (of_irq_map_one(dev, index, &oirq))
+                return NO_IRQ;
+
+        return irq_create_of_mapping(oirq.controller, oirq.specifier,
+                                     oirq.size);
+}
+EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
+
+void irq_dispose_mapping(unsigned int virq)
+{
+        struct irq_host *host = irq_map[virq].host;
+        irq_hw_number_t hwirq;
+        unsigned long flags;
+
+        WARN_ON (host == NULL);
+        if (host == NULL)
+                return;
+
+        /* Never unmap legacy interrupts */
+        if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
+                return;
+
+        /* remove chip and handler */
+        set_irq_chip_and_handler(virq, NULL, NULL);
+
+        /* Make sure it's completed */
+        synchronize_irq(virq);
+
+        /* Tell the PIC about it */
+        if (host->ops->unmap)
+                host->ops->unmap(host, virq);
+        smp_mb();
+
+        /* Clear reverse map */
+        hwirq = irq_map[virq].hwirq;
+        switch(host->revmap_type) {
+        case IRQ_HOST_MAP_LINEAR:
+                if (hwirq < host->revmap_data.linear.size)
+                        host->revmap_data.linear.revmap[hwirq] = IRQ_NONE;
+                break;
+        case IRQ_HOST_MAP_TREE:
+                /* Check if radix tree allocated yet */
+                if (host->revmap_data.tree.gfp_mask == 0)
+                        break;
+                /* XXX radix tree not safe ! remove lock whem it becomes safe
+                 * and use some RCU sync to make sure everything is ok before we
+                 * can re-use that map entry
+                 */
+                spin_lock_irqsave(&irq_big_lock, flags);
+                radix_tree_delete(&host->revmap_data.tree, hwirq);
+                spin_unlock_irqrestore(&irq_big_lock, flags);
+                break;
+        }
+
+        /* Destroy map */
+        smp_mb();
+        irq_map[virq].hwirq = host->inval_irq;
+
+        /* Set some flags */
+        get_irq_desc(virq)->status |= IRQ_NOREQUEST;
+
+        /* Free it */
+        irq_free_virt(virq, 1);
+}
+EXPORT_SYMBOL_GPL(irq_dispose_mapping);
+
+unsigned int irq_find_mapping(struct irq_host *host,
+                              irq_hw_number_t hwirq)
+{
+        unsigned int i;
+        unsigned int hint = hwirq % irq_virq_count;
+
+        /* Look for default host if nececssary */
+        if (host == NULL)
+                host = irq_default_host;
+        if (host == NULL)
+                return NO_IRQ;
+
+        /* legacy -> bail early */
+        if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
+                return hwirq;
+
+        /* Slow path does a linear search of the map */
+        if (hint < NUM_ISA_INTERRUPTS)
+                hint = NUM_ISA_INTERRUPTS;
+        i = hint;
+        do  {
+                if (irq_map[i].host == host &&
+                    irq_map[i].hwirq == hwirq)
+                        return i;
+                i++;
+                if (i >= irq_virq_count)
+                        i = NUM_ISA_INTERRUPTS;
+        } while(i != hint);
+        return NO_IRQ;
+}
+EXPORT_SYMBOL_GPL(irq_find_mapping);
+
+
+unsigned int irq_radix_revmap(struct irq_host *host,
+                              irq_hw_number_t hwirq)
+{
+        struct radix_tree_root *tree;
+        struct irq_map_entry *ptr;
+        unsigned int virq;
+        unsigned long flags;
+
+        WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
+
+        /* Check if the radix tree exist yet. We test the value of
+         * the gfp_mask for that. Sneaky but saves another int in the
+         * structure. If not, we fallback to slow mode
+         */
+        tree = &host->revmap_data.tree;
+        if (tree->gfp_mask == 0)
+                return irq_find_mapping(host, hwirq);
+
+        /* XXX Current radix trees are NOT SMP safe !!! Remove that lock
+         * when that is fixed (when Nick's patch gets in
+         */
+        spin_lock_irqsave(&irq_big_lock, flags);
+
+        /* Now try to resolve */
+        ptr = radix_tree_lookup(tree, hwirq);
+        /* Found it, return */
+        if (ptr) {
+                virq = ptr - irq_map;
+                goto bail;
+        }
+
+        /* If not there, try to insert it */
+        virq = irq_find_mapping(host, hwirq);
+        if (virq != NO_IRQ)
+                radix_tree_insert(tree, virq, &irq_map[virq]);
+ bail:
+        spin_unlock_irqrestore(&irq_big_lock, flags);
+        return virq;
+}
+
+unsigned int irq_linear_revmap(struct irq_host *host,
+                               irq_hw_number_t hwirq)
+{
+        unsigned int *revmap;
+
+        WARN_ON(host->revmap_type != IRQ_HOST_MAP_LINEAR);
+
+        /* Check revmap bounds */
+        if (unlikely(hwirq >= host->revmap_data.linear.size))
+                return irq_find_mapping(host, hwirq);
+
+        /* Check if revmap was allocated */
+        revmap = host->revmap_data.linear.revmap;
+        if (unlikely(revmap == NULL))
+                return irq_find_mapping(host, hwirq);
+
+        /* Fill up revmap with slow path if no mapping found */
+        if (unlikely(revmap[hwirq] == NO_IRQ))
+                revmap[hwirq] = irq_find_mapping(host, hwirq);
+
+        return revmap[hwirq];
+}
+
+unsigned int irq_alloc_virt(struct irq_host *host,
+                            unsigned int count,
+                            unsigned int hint)
+{
+        unsigned long flags;
+        unsigned int i, j, found = NO_IRQ;
+        unsigned int limit = irq_virq_count - count;
+
+        if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
+                return NO_IRQ;
+
+        spin_lock_irqsave(&irq_big_lock, flags);
+
+        /* Use hint for 1 interrupt if any */
+        if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
+            hint < irq_virq_count && irq_map[hint].host == NULL) {
+                found = hint;
+                goto hint_found;
+        }
+
+        /* Look for count consecutive numbers in the allocatable
+         * (non-legacy) space
+         */
+        for (i = NUM_ISA_INTERRUPTS; i <= limit; ) {
+                for (j = i; j < (i + count); j++)
+                        if (irq_map[j].host != NULL) {
+                                i = j + 1;
+                                continue;
+                        }
+                found = i;
+                break;
+        }
+        if (found == NO_IRQ) {
+                spin_unlock_irqrestore(&irq_big_lock, flags);
+                return NO_IRQ;
+        }
+ hint_found:
+        for (i = found; i < (found + count); i++) {
+                irq_map[i].hwirq = host->inval_irq;
+                smp_wmb();
+                irq_map[i].host = host;
+        }
+        spin_unlock_irqrestore(&irq_big_lock, flags);
+        return found;
+}
+
+void irq_free_virt(unsigned int virq, unsigned int count)
+{
+        unsigned long flags;
+        unsigned int i;
+
+        WARN_ON (virq < NUM_ISA_INTERRUPTS);
+        WARN_ON (count == 0 || (virq + count) > irq_virq_count);
+
+        spin_lock_irqsave(&irq_big_lock, flags);
+        for (i = virq; i < (virq + count); i++) {
+                struct irq_host *host;
+
+                if (i < NUM_ISA_INTERRUPTS ||
+                    (virq + count) > irq_virq_count)
+                        continue;
+
+                host = irq_map[i].host;
+                irq_map[i].hwirq = host->inval_irq;
+                smp_wmb();
+                irq_map[i].host = NULL;
+        }
+        spin_unlock_irqrestore(&irq_big_lock, flags);
+}
+
+void irq_early_init(void)
+{
+        unsigned int i;
+
+        for (i = 0; i < NR_IRQS; i++)
+                get_irq_desc(i)->status |= IRQ_NOREQUEST;
+}
+
+/* We need to create the radix trees late */
+static int irq_late_init(void)
+{
+        struct irq_host *h;
+        unsigned long flags;
+
+        spin_lock_irqsave(&irq_big_lock, flags);
+        list_for_each_entry(h, &irq_hosts, link) {
+                if (h->revmap_type == IRQ_HOST_MAP_TREE)
+                        INIT_RADIX_TREE(&h->revmap_data.tree, GFP_ATOMIC);
+        }
+        spin_unlock_irqrestore(&irq_big_lock, flags);
+
+        return 0;
+}
+arch_initcall(irq_late_init);
+
+#endif /* CONFIG_PPC_MERGE */
+
 #ifdef CONFIG_PCI_MSI
 int pci_enable_msi(struct pci_dev * pdev)
 {
diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c
index a55056676ca4..7e98e778b52f 100644
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c
@@ -28,6 +28,7 @@ static struct legacy_serial_info {
         struct device_node              *np;
         unsigned int                    speed;
         unsigned int                    clock;
+        int                             irq_check_parent;
         phys_addr_t                     taddr;
 } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
 static unsigned int legacy_serial_count;
@@ -36,7 +37,7 @@ static int legacy_serial_console = -1;
 static int __init add_legacy_port(struct device_node *np, int want_index,
                                   int iotype, phys_addr_t base,
                                   phys_addr_t taddr, unsigned long irq,
-                                  upf_t flags)
+                                  upf_t flags, int irq_check_parent)
 {
         u32 *clk, *spd, clock = BASE_BAUD * 16;
         int index;
@@ -68,7 +69,7 @@ static int __init add_legacy_port(struct device_node *np, int want_index,
         if (legacy_serial_infos[index].np != 0) {
                 /* if we still have some room, move it, else override */
                 if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
-                        printk(KERN_INFO "Moved legacy port %d -> %d\n",
+                        printk(KERN_DEBUG "Moved legacy port %d -> %d\n",
                                index, legacy_serial_count);
                         legacy_serial_ports[legacy_serial_count] =
                                 legacy_serial_ports[index];
@@ -76,7 +77,7 @@ static int __init add_legacy_port(struct device_node *np, int want_index,
                                 legacy_serial_infos[index];
                         legacy_serial_count++;
                 } else {
-                        printk(KERN_INFO "Replacing legacy port %d\n", index);
+                        printk(KERN_DEBUG "Replacing legacy port %d\n", index);
                 }
         }
 
@@ -95,10 +96,11 @@ static int __init add_legacy_port(struct device_node *np, int want_index,
         legacy_serial_infos[index].np = of_node_get(np);
         legacy_serial_infos[index].clock = clock;
         legacy_serial_infos[index].speed = spd ? *spd : 0;
+        legacy_serial_infos[index].irq_check_parent = irq_check_parent;
 
-        printk(KERN_INFO "Found legacy serial port %d for %s\n",
+        printk(KERN_DEBUG "Found legacy serial port %d for %s\n",
                index, np->full_name);
-        printk(KERN_INFO "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
+        printk(KERN_DEBUG "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
                (iotype == UPIO_PORT) ? "port" : "mem",
                (unsigned long long)base, (unsigned long long)taddr, irq,
                legacy_serial_ports[index].uartclk,
@@ -132,7 +134,7 @@ static int __init add_legacy_soc_port(struct device_node *np,
         /* Add port, irq will be dealt with later. We passed a translated
          * IO port value. It will be fixed up later along with the irq
          */
-        return add_legacy_port(np, -1, UPIO_MEM, addr, addr, NO_IRQ, flags);
+        return add_legacy_port(np, -1, UPIO_MEM, addr, addr, NO_IRQ, flags, 0);
 }
 
 static int __init add_legacy_isa_port(struct device_node *np,
@@ -170,7 +172,7 @@ static int __init add_legacy_isa_port(struct device_node *np,
 
         /* Add port, irq will be dealt with later */
         return add_legacy_port(np, index, UPIO_PORT, reg[1], taddr,
-                               NO_IRQ, UPF_BOOT_AUTOCONF);
+                               NO_IRQ, UPF_BOOT_AUTOCONF, 0);
 
 }
 
@@ -242,7 +244,8 @@ static int __init add_legacy_pci_port(struct device_node *np,
         /* Add port, irq will be dealt with later. We passed a translated
          * IO port value. It will be fixed up later along with the irq
          */
-        return add_legacy_port(np, index, iotype, base, addr, NO_IRQ, UPF_BOOT_AUTOCONF);
+        return add_legacy_port(np, index, iotype, base, addr, NO_IRQ,
+                               UPF_BOOT_AUTOCONF, np != pci_dev);
 }
 #endif
 
@@ -373,27 +376,22 @@ static void __init fixup_port_irq(int index,
                                   struct device_node *np,
                                   struct plat_serial8250_port *port)
 {
+        unsigned int virq;
+
         DBG("fixup_port_irq(%d)\n", index);
 
-        /* Check for interrupts in that node */
-        if (np->n_intrs > 0) {
-                port->irq = np->intrs[0].line;
-                DBG(" port %d (%s), irq=%d\n",
-                    index, np->full_name, port->irq);
-                return;
+        virq = irq_of_parse_and_map(np, 0);
+        if (virq == NO_IRQ && legacy_serial_infos[index].irq_check_parent) {
+                np = of_get_parent(np);
+                if (np == NULL)
+                        return;
+                virq = irq_of_parse_and_map(np, 0);
+                of_node_put(np);
         }
-
-        /* Check for interrupts in the parent */
-        np = of_get_parent(np);
-        if (np == NULL)
+        if (virq == NO_IRQ)
                 return;
 
-        if (np->n_intrs > 0) {
-                port->irq = np->intrs[0].line;
-                DBG(" port %d (%s), irq=%d\n",
-                    index, np->full_name, port->irq);
-        }
-        of_node_put(np);
+        port->irq = virq;
 }
 
 static void __init fixup_port_pio(int index,
diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c
index 1333335c474e..898dae8ab6d9 100644
--- a/arch/powerpc/kernel/pci_32.c
+++ b/arch/powerpc/kernel/pci_32.c
@@ -1404,6 +1404,43 @@ pcibios_update_irq(struct pci_dev *dev, int irq)
         /* XXX FIXME - update OF device tree node interrupt property */
 }
 
+#ifdef CONFIG_PPC_MERGE
+/* XXX This is a copy of the ppc64 version. This is temporary until we start
+ * merging the 2 PCI layers
+ */
+/*
+ * Reads the interrupt pin to determine if interrupt is use by card.
+ * If the interrupt is used, then gets the interrupt line from the
+ * openfirmware and sets it in the pci_dev and pci_config line.
+ */
+int pci_read_irq_line(struct pci_dev *pci_dev)
+{
+        struct of_irq oirq;
+        unsigned int virq;
+
+        DBG("Try to map irq for %s...\n", pci_name(pci_dev));
+
+        if (of_irq_map_pci(pci_dev, &oirq)) {
+                DBG(" -> failed !\n");
+                return -1;
+        }
+
+        DBG(" -> got one, spec %d cells (0x%08x...) on %s\n",
+            oirq.size, oirq.specifier[0], oirq.controller->full_name);
+
+        virq = irq_create_of_mapping(oirq.controller, oirq.specifier, oirq.size);
+        if(virq == NO_IRQ) {
+                DBG(" -> failed to map !\n");
+                return -1;
+        }
+        pci_dev->irq = virq;
+        pci_write_config_byte(pci_dev, PCI_INTERRUPT_LINE, virq);
+
+        return 0;
+}
+EXPORT_SYMBOL(pci_read_irq_line);
+#endif /* CONFIG_PPC_MERGE */
+
 int pcibios_enable_device(struct pci_dev *dev, int mask)
 {
         u16 cmd, old_cmd;
diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
index bea8451fb57b..efc0b5559ee0 100644
--- a/arch/powerpc/kernel/pci_64.c
+++ b/arch/powerpc/kernel/pci_64.c
@@ -398,12 +398,8 @@ struct pci_dev *of_create_pci_dev(struct device_node *node,
         } else {
                 dev->hdr_type = PCI_HEADER_TYPE_NORMAL;
                 dev->rom_base_reg = PCI_ROM_ADDRESS;
+                /* Maybe do a default OF mapping here */
                 dev->irq = NO_IRQ;
-                if (node->n_intrs > 0) {
-                        dev->irq = node->intrs[0].line;
-                        pci_write_config_byte(dev, PCI_INTERRUPT_LINE,
-                                              dev->irq);
-                }
         }
 
         pci_parse_of_addrs(node, dev);
@@ -1288,23 +1284,26 @@ EXPORT_SYMBOL(pcibios_fixup_bus);
  */
 int pci_read_irq_line(struct pci_dev *pci_dev)
 {
-        u8 intpin;
-        struct device_node *node;
-
-        pci_read_config_byte(pci_dev, PCI_INTERRUPT_PIN, &intpin);
-        if (intpin == 0)
-                return 0;
+        struct of_irq oirq;
+        unsigned int virq;
 
-        node = pci_device_to_OF_node(pci_dev);
-        if (node == NULL)
-                return -1;
+        DBG("Try to map irq for %s...\n", pci_name(pci_dev));
 
-        if (node->n_intrs == 0)
+        if (of_irq_map_pci(pci_dev, &oirq)) {
+                DBG(" -> failed !\n");
                 return -1;
+        }
 
-        pci_dev->irq = node->intrs[0].line;
+        DBG(" -> got one, spec %d cells (0x%08x...) on %s\n",
+            oirq.size, oirq.specifier[0], oirq.controller->full_name);
 
-        pci_write_config_byte(pci_dev, PCI_INTERRUPT_LINE, pci_dev->irq);
+        virq = irq_create_of_mapping(oirq.controller, oirq.specifier, oirq.size);
+        if(virq == NO_IRQ) {
+                DBG(" -> failed to map !\n");
+                return -1;
+        }
+        pci_dev->irq = virq;
+        pci_write_config_byte(pci_dev, PCI_INTERRUPT_LINE, virq);
 
         return 0;
 }
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index ef3619c28702..a1787ffb6319 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -30,6 +30,7 @@
 #include <linux/module.h>
 #include <linux/kexec.h>
 #include <linux/debugfs.h>
+#include <linux/irq.h>
 
 #include <asm/prom.h>
 #include <asm/rtas.h>
@@ -86,424 +87,6 @@ static DEFINE_RWLOCK(devtree_lock);
 /* export that to outside world */
 struct device_node *of_chosen;
 
-struct device_node *dflt_interrupt_controller;
-int num_interrupt_controllers;
-
-/*
- * Wrapper for allocating memory for various data that needs to be
- * attached to device nodes as they are processed at boot or when
- * added to the device tree later (e.g. DLPAR).  At boot there is
- * already a region reserved so we just increment *mem_start by size;
- * otherwise we call kmalloc.
- */
-static void * prom_alloc(unsigned long size, unsigned long *mem_start)
-{
-        unsigned long tmp;
-
-        if (!mem_start)
-                return kmalloc(size, GFP_KERNEL);
-
-        tmp = *mem_start;
-        *mem_start += size;
-        return (void *)tmp;
-}
-
-/*
- * Find the device_node with a given phandle.
- */
-static struct device_node * find_phandle(phandle ph)
-{
-        struct device_node *np;
-
-        for (np = allnodes; np != 0; np = np->allnext)
-                if (np->linux_phandle == ph)
-                        return np;
-        return NULL;
-}
-
-/*
- * Find the interrupt parent of a node.
- */
-static struct device_node * __devinit intr_parent(struct device_node *p)
-{
-        phandle *parp;
-
-        parp = (phandle *) get_property(p, "interrupt-parent", NULL);
-        if (parp == NULL)
-                return p->parent;
-        p = find_phandle(*parp);
-        if (p != NULL)
-                return p;
-        /*
-         * On a powermac booted with BootX, we don't get to know the
-         * phandles for any nodes, so find_phandle will return NULL.
-         * Fortunately these machines only have one interrupt controller
-         * so there isn't in fact any ambiguity.  -- paulus
-         */
-        if (num_interrupt_controllers == 1)
-                p = dflt_interrupt_controller;
-        return p;
-}
-
-/*
- * Find out the size of each entry of the interrupts property
- * for a node.
- */
-int __devinit prom_n_intr_cells(struct device_node *np)
-{
-        struct device_node *p;
-        unsigned int *icp;
-
-        for (p = np; (p = intr_parent(p)) != NULL; ) {
-                icp = (unsigned int *)
-                        get_property(p, "#interrupt-cells", NULL);
-                if (icp != NULL)
-                        return *icp;
-                if (get_property(p, "interrupt-controller", NULL) != NULL
-                    || get_property(p, "interrupt-map", NULL) != NULL) {
-                        printk("oops, node %s doesn't have #interrupt-cells\n",
-                               p->full_name);
-                        return 1;
-                }
-        }
-#ifdef DEBUG_IRQ
-        printk("prom_n_intr_cells failed for %s\n", np->full_name);
-#endif
-        return 1;
-}
-
-/*
- * Map an interrupt from a device up to the platform interrupt
- * descriptor.
- */
-static int __devinit map_interrupt(unsigned int **irq, struct device_node **ictrler,
-                                   struct device_node *np, unsigned int *ints,
-                                   int nintrc)
-{
-        struct device_node *p, *ipar;
-        unsigned int *imap, *imask, *ip;
-        int i, imaplen, match;
-        int newintrc = 0, newaddrc = 0;
-        unsigned int *reg;
-        int naddrc;
-
-        reg = (unsigned int *) get_property(np, "reg", NULL);
-        naddrc = prom_n_addr_cells(np);
-        p = intr_parent(np);
-        while (p != NULL) {
-                if (get_property(p, "interrupt-controller", NULL) != NULL)
-                        /* this node is an interrupt controller, stop here */
-                        break;
-                imap = (unsigned int *)
-                        get_property(p, "interrupt-map", &imaplen);
-                if (imap == NULL) {
-                        p = intr_parent(p);
-                        continue;
-                }
-                imask = (unsigned int *)
-                        get_property(p, "interrupt-map-mask", NULL);
-                if (imask == NULL) {
-                        printk("oops, %s has interrupt-map but no mask\n",
-                               p->full_name);
-                        return 0;
-                }
-                imaplen /= sizeof(unsigned int);
-                match = 0;
-                ipar = NULL;
-                while (imaplen > 0 && !match) {
-                        /* check the child-interrupt field */
-                        match = 1;
-                        for (i = 0; i < naddrc && match; ++i)
-                                match = ((reg[i] ^ imap[i]) & imask[i]) == 0;
-                        for (; i < naddrc + nintrc && match; ++i)
-                                match = ((ints[i-naddrc] ^ imap[i]) & imask[i]) == 0;
-                        imap += naddrc + nintrc;
-                        imaplen -= naddrc + nintrc;
-                        /* grab the interrupt parent */
-                        ipar = find_phandle((phandle) *imap++);
-                        --imaplen;
-                        if (ipar == NULL && num_interrupt_controllers == 1)
-                                /* cope with BootX not giving us phandles */
-                                ipar = dflt_interrupt_controller;
-                        if (ipar == NULL) {
-                                printk("oops, no int parent %x in map of %s\n",
-                                       imap[-1], p->full_name);
-                                return 0;
-                        }
-                        /* find the parent's # addr and intr cells */
-                        ip = (unsigned int *)
-                                get_property(ipar, "#interrupt-cells", NULL);
-                        if (ip == NULL) {
-                                printk("oops, no #interrupt-cells on %s\n",
-                                       ipar->full_name);
-                                return 0;
-                        }
-                        newintrc = *ip;
-                        ip = (unsigned int *)
-                                get_property(ipar, "#address-cells", NULL);
-                        newaddrc = (ip == NULL)? 0: *ip;
-                        imap += newaddrc + newintrc;
-                        imaplen -= newaddrc + newintrc;
-                }
-                if (imaplen < 0) {
-                        printk("oops, error decoding int-map on %s, len=%d\n",
-                               p->full_name, imaplen);
-                        return 0;
-                }
-                if (!match) {
-#ifdef DEBUG_IRQ
-                        printk("oops, no match in %s int-map for %s\n",
-                               p->full_name, np->full_name);
-#endif
-                        return 0;
-                }
-                p = ipar;
-                naddrc = newaddrc;
-                nintrc = newintrc;
-                ints = imap - nintrc;
-                reg = ints - naddrc;
-        }
-        if (p == NULL) {
-#ifdef DEBUG_IRQ
-                printk("hmmm, int tree for %s doesn't have ctrler\n",
-                       np->full_name);
-#endif
-                return 0;
-        }
-        *irq = ints;
-        *ictrler = p;
-        return nintrc;
-}
-
-static unsigned char map_isa_senses[4] = {
-        IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE,
-        IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE,
-        IRQ_SENSE_EDGE  | IRQ_POLARITY_NEGATIVE,
-        IRQ_SENSE_EDGE  | IRQ_POLARITY_POSITIVE
-};
-
-static unsigned char map_mpic_senses[4] = {
-        IRQ_SENSE_EDGE  | IRQ_POLARITY_POSITIVE,
-        IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE,
-        /* 2 seems to be used for the 8259 cascade... */
-        IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE,
-        IRQ_SENSE_EDGE  | IRQ_POLARITY_NEGATIVE,
-};
-
-static int __devinit finish_node_interrupts(struct device_node *np,
-                                            unsigned long *mem_start,
-                                            int measure_only)
-{
-        unsigned int *ints;
-        int intlen, intrcells, intrcount;
-        int i, j, n, sense;
-        unsigned int *irq, virq;
-        struct device_node *ic;
-        int trace = 0;
-
-        //#define TRACE(fmt...) do { if (trace) { printk(fmt); mdelay(1000); } } while(0)
-#define TRACE(fmt...)
-
-        if (!strcmp(np->name, "smu-doorbell"))
-                trace = 1;
-
-        TRACE("Finishing SMU doorbell ! num_interrupt_controllers = %d\n",
-              num_interrupt_controllers);
-
-        if (num_interrupt_controllers == 0) {
-                /*
-                 * Old machines just have a list of interrupt numbers
-                 * and no interrupt-controller nodes.
-                 */
-                ints = (unsigned int *) get_property(np, "AAPL,interrupts",
-                                                     &intlen);
-                /* XXX old interpret_pci_props looked in parent too */
-                /* XXX old interpret_macio_props looked for interrupts
-                   before AAPL,interrupts */
-                if (ints == NULL)
-                        ints = (unsigned int *) get_property(np, "interrupts",
-                                                             &intlen);
-                if (ints == NULL)
-                        return 0;
-
-                np->n_intrs = intlen / sizeof(unsigned int);
-                np->intrs = prom_alloc(np->n_intrs * sizeof(np->intrs[0]),
-                                       mem_start);
-                if (!np->intrs)
-                        return -ENOMEM;
-                if (measure_only)
-                        return 0;
-
-                for (i = 0; i < np->n_intrs; ++i) {
-                        np->intrs[i].line = *ints++;
-                        np->intrs[i].sense = IRQ_SENSE_LEVEL
-                                | IRQ_POLARITY_NEGATIVE;
-                }
-                return 0;
-        }
-
-        ints = (unsigned int *) get_property(np, "interrupts", &intlen);
-        TRACE("ints=%p, intlen=%d\n", ints, intlen);
-        if (ints == NULL)
-                return 0;
-        intrcells = prom_n_intr_cells(np);
-        intlen /= intrcells * sizeof(unsigned int);
-        TRACE("intrcells=%d, new intlen=%d\n", intrcells, intlen);
-        np->intrs = prom_alloc(intlen * sizeof(*(np->intrs)), mem_start);
-        if (!np->intrs)
-                return -ENOMEM;
-
-        if (measure_only)
-                return 0;
-
-        intrcount = 0;
-        for (i = 0; i < intlen; ++i, ints += intrcells) {
-                n = map_interrupt(&irq, &ic, np, ints, intrcells);
-                TRACE("map, irq=%d, ic=%p, n=%d\n", irq, ic, n);
-                if (n <= 0)
-                        continue;
-
-                /* don't map IRQ numbers under a cascaded 8259 controller */
-                if (ic && device_is_compatible(ic, "chrp,iic")) {
-                        np->intrs[intrcount].line = irq[0];
-                        sense = (n > 1)? (irq[1] & 3): 3;
-                        np->intrs[intrcount].sense = map_isa_senses[sense];
-                } else {
-                        virq = virt_irq_create_mapping(irq[0]);
-                        TRACE("virq=%d\n", virq);
-#ifdef CONFIG_PPC64
-                        if (virq == NO_IRQ) {
-                                printk(KERN_CRIT "Could not allocate interrupt"
-                                       " number for %s\n", np->full_name);
-                                continue;
-                        }
-#endif
-                        np->intrs[intrcount].line = irq_offset_up(virq);
-                        sense = (n > 1)? (irq[1] & 3): 1;
-
-                        /* Apple uses bits in there in a different way, let's
-                         * only keep the real sense bit on macs
-                         */
-                        if (machine_is(powermac))
-                                sense &= 0x1;
-                        np->intrs[intrcount].sense = map_mpic_senses[sense];
-                }
-
-#ifdef CONFIG_PPC64
-                /* We offset irq numbers for the u3 MPIC by 128 in PowerMac */
-                if (machine_is(powermac) && ic && ic->parent) {
-                        char *name = get_property(ic->parent, "name", NULL);
-                        if (name && !strcmp(name, "u3"))
-                                np->intrs[intrcount].line += 128;
-                        else if (!(name && (!strcmp(name, "mac-io") ||
-                                            !strcmp(name, "u4"))))
-                                /* ignore other cascaded controllers, such as
-                                   the k2-sata-root */
-                                break;
-                }
-#endif /* CONFIG_PPC64 */
-                if (n > 2) {
-                        printk("hmmm, got %d intr cells for %s:", n,
-                               np->full_name);
-                        for (j = 0; j < n; ++j)
-                                printk(" %d", irq[j]);
-                        printk("\n");
-                }
-                ++intrcount;
-        }
-        np->n_intrs = intrcount;
-
-        return 0;
-}
-
-static int __devinit finish_node(struct device_node *np,
-                                 unsigned long *mem_start,
-                                 int measure_only)
-{
-        struct device_node *child;
-        int rc = 0;
-
-        rc = finish_node_interrupts(np, mem_start, measure_only);
-        if (rc)
-                goto out;
-
-        for (child = np->child; child != NULL; child = child->sibling) {
-                rc = finish_node(child, mem_start, measure_only);
-                if (rc)
-                        goto out;
-        }
-out:
-        return rc;
-}
-
-static void __init scan_interrupt_controllers(void)
-{
-        struct device_node *np;
-        int n = 0;
-        char *name, *ic;
-        int iclen;
-
-        for (np = allnodes; np != NULL; np = np->allnext) {
-                ic = get_property(np, "interrupt-controller", &iclen);
-                name = get_property(np, "name", NULL);
-                /* checking iclen makes sure we don't get a false
-                   match on /chosen.interrupt_controller */
-                if ((name != NULL
-                     && strcmp(name, "interrupt-controller") == 0)
-                    || (ic != NULL && iclen == 0
-                        && strcmp(name, "AppleKiwi"))) {
-                        if (n == 0)
-                                dflt_interrupt_controller = np;
-                        ++n;
-                }
-        }
-        num_interrupt_controllers = n;
-}
-
-/**
- * finish_device_tree is called once things are running normally
- * (i.e. with text and data mapped to the address they were linked at).
- * It traverses the device tree and fills in some of the additional,
- * fields in each node like {n_}addrs and {n_}intrs, the virt interrupt
- * mapping is also initialized at this point.
- */
-void __init finish_device_tree(void)
-{
-        unsigned long start, end, size = 0;
-
-        DBG(" -> finish_device_tree\n");
-
-#ifdef CONFIG_PPC64
-        /* Initialize virtual IRQ map */
-        virt_irq_init();
-#endif
-        scan_interrupt_controllers();
-
-        /*
-         * Finish device-tree (pre-parsing some properties etc...)
-         * We do this in 2 passes. One with "measure_only" set, which
-         * will only measure the amount of memory needed, then we can
-         * allocate that memory, and call finish_node again. However,
-         * we must be careful as most routines will fail nowadays when
-         * prom_alloc() returns 0, so we must make sure our first pass
-         * doesn't start at 0. We pre-initialize size to 16 for that
-         * reason and then remove those additional 16 bytes
-         */
-        size = 16;
-        finish_node(allnodes, &size, 1);
-        size -= 16;
-
-        if (0 == size)
-                end = start = 0;
-        else
-                end = start = (unsigned long)__va(lmb_alloc(size, 128));
-
-        finish_node(allnodes, &end, 0);
-        BUG_ON(end != start + size);
-
-        DBG(" <- finish_device_tree\n");
-}
-
 static inline char *find_flat_dt_string(u32 offset)
 {
         return ((char *)initial_boot_params) +
@@ -1389,27 +972,6 @@ prom_n_size_cells(struct device_node* np)
 EXPORT_SYMBOL(prom_n_size_cells);
 
 /**
- * Work out the sense (active-low level / active-high edge)
- * of each interrupt from the device tree.
- */
-void __init prom_get_irq_senses(unsigned char *senses, int off, int max)
-{
-        struct device_node *np;
-        int i, j;
-
-        /* default to level-triggered */
-        memset(senses, IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE, max - off);
-
-        for (np = allnodes; np != 0; np = np->allnext) {
-                for (j = 0; j < np->n_intrs; j++) {
-                        i = np->intrs[j].line;
-                        if (i >= off && i < max)
-                                senses[i-off] = np->intrs[j].sense;
-                }
-        }
-}
-
-/**
  * Construct and return a list of the device_nodes with a given name.
  */
 struct device_node *find_devices(const char *name)
@@ -1808,7 +1370,6 @@ static void of_node_release(struct kref *kref)
                         node->deadprops = NULL;
                 }
         }
-        kfree(node->intrs);
         kfree(node->full_name);
         kfree(node->data);
         kfree(node);
@@ -1881,13 +1442,7 @@ void of_detach_node(const struct device_node *np)
 #ifdef CONFIG_PPC_PSERIES
 /*
  * Fix up the uninitialized fields in a new device node:
- * name, type, n_addrs, addrs, n_intrs, intrs, and pci-specific fields
- *
- * A lot of boot-time code is duplicated here, because functions such
- * as finish_node_interrupts, interpret_pci_props, etc. cannot use the
- * slab allocator.
- *
- * This should probably be split up into smaller chunks.
+ * name, type and pci-specific fields
  */
 
 static int of_finish_dynamic_node(struct device_node *node)
@@ -1928,8 +1483,6 @@ static int prom_reconfig_notifier(struct notifier_block *nb,
         switch (action) {
         case PSERIES_RECONFIG_ADD:
                 err = of_finish_dynamic_node(node);
-                if (!err)
-                        finish_node(node, NULL, 0);
                 if (err < 0) {
                         printk(KERN_ERR "finish_node returned %d\n", err);
                         err = NOTIFY_BAD;
diff --git a/arch/powerpc/kernel/rtas_pci.c b/arch/powerpc/kernel/rtas_pci.c
index 6eb7e49b394a..cda022657324 100644
--- a/arch/powerpc/kernel/rtas_pci.c
+++ b/arch/powerpc/kernel/rtas_pci.c
@@ -297,19 +297,9 @@ unsigned long __init find_and_init_phbs(void)
         struct device_node *node;
         struct pci_controller *phb;
         unsigned int index;
-        unsigned int root_size_cells = 0;
-        unsigned int *opprop = NULL;
         struct device_node *root = of_find_node_by_path("/");
 
-        if (ppc64_interrupt_controller == IC_OPEN_PIC) {
-                opprop = (unsigned int *)get_property(root,
-                                "platform-open-pic", NULL);
-        }
-
-        root_size_cells = prom_n_size_cells(root);
-
         index = 0;
-
         for (node = of_get_next_child(root, NULL);
              node != NULL;
              node = of_get_next_child(root, node)) {
@@ -324,13 +314,6 @@ unsigned long __init find_and_init_phbs(void)
                 setup_phb(node, phb);
                 pci_process_bridge_OF_ranges(phb, node, 0);
                 pci_setup_phb_io(phb, index == 0);
-#ifdef CONFIG_PPC_PSERIES
-                /* XXX This code need serious fixing ... --BenH */
-                if (ppc64_interrupt_controller == IC_OPEN_PIC && pSeries_mpic) {
-                        int addr = root_size_cells * (index + 2) - 1;
-                        mpic_assign_isu(pSeries_mpic, index, opprop[addr]);
-                }
-#endif
                 index++;
         }
 
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 0c21de39c161..e0df2ba1ab9f 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -239,7 +239,6 @@ void __init setup_arch(char **cmdline_p)
                 ppc_md.init_early();
 
         find_legacy_serial_ports();
-        finish_device_tree();
 
         smp_setup_cpu_maps();
 
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index ac7276c40685..fd1785e4c9bb 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -361,12 +361,15 @@ void __init setup_system(void)
 
         /*
          * Fill the ppc64_caches & systemcfg structures with informations
-         * retrieved from the device-tree. Need to be called before
-         * finish_device_tree() since the later requires some of the
-         * informations filled up here to properly parse the interrupt tree.
+         * retrieved from the device-tree.
          */
         initialize_cache_info();
 
+        /*
+         * Initialize irq remapping subsystem
+         */
+        irq_early_init();
+
 #ifdef CONFIG_PPC_RTAS
         /*
          * Initialize RTAS if available
@@ -394,12 +397,6 @@ void __init setup_system(void)
         find_legacy_serial_ports();
 
         /*
-         * "Finish" the device-tree, that is do the actual parsing of
-         * some of the properties like the interrupt map
-         */
-        finish_device_tree();
-
-        /*
          * Initialize xmon
          */
 #ifdef CONFIG_XMON_DEFAULT
@@ -427,8 +424,6 @@ void __init setup_system(void)
 
         printk("-----------------------------------------------------\n");
         printk("ppc64_pft_size                = 0x%lx\n", ppc64_pft_size);
-        printk("ppc64_interrupt_controller    = 0x%ld\n",
-               ppc64_interrupt_controller);
         printk("physicalMemorySize            = 0x%lx\n", lmb_phys_mem_size());
         printk("ppc64_caches.dcache_line_size = 0x%x\n",
                ppc64_caches.dline_size);
diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index cdf5867838a6..fad8580f9081 100644
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -218,7 +218,6 @@ struct vio_dev * __devinit vio_register_device_node(struct device_node *of_node)
 {
         struct vio_dev *viodev;
         unsigned int *unit_address;
-        unsigned int *irq_p;
 
         /* we need the 'device_type' property, in order to match with drivers */
         if (of_node->type == NULL) {
@@ -243,16 +242,7 @@ struct vio_dev * __devinit vio_register_device_node(struct device_node *of_node)
 
         viodev->dev.platform_data = of_node_get(of_node);
 
-        viodev->irq = NO_IRQ;
-        irq_p = (unsigned int *)get_property(of_node, "interrupts", NULL);
-        if (irq_p) {
-                int virq = virt_irq_create_mapping(*irq_p);
-                if (virq == NO_IRQ) {
-                        printk(KERN_ERR "Unable to allocate interrupt "
-                               "number for %s\n", of_node->full_name);
-                } else
-                        viodev->irq = irq_offset_up(virq);
-        }
+        viodev->irq = irq_of_parse_and_map(of_node, 0);
 
         snprintf(viodev->dev.bus_id, BUS_ID_SIZE, "%x", *unit_address);
         viodev->name = of_node->name;