1 files changed, 516 insertions, 137 deletions

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index e3774f6b57cc..8cf987809c66 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>
@@ -57,39 +62,38 @@
 #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
 
 int __irq_offset_value;
-#ifdef CONFIG_PPC32
-EXPORT_SYMBOL(__irq_offset_value);
-#endif
-
 static int ppc_spurious_interrupts;
 
 #ifdef CONFIG_PPC32
-#define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
+EXPORT_SYMBOL(__irq_offset_value);
+atomic_t ppc_n_lost_interrupts;
 
+#ifndef CONFIG_PPC_MERGE
+#define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
-atomic_t ppc_n_lost_interrupts;
+#endif
 
 #ifdef CONFIG_TAU_INT
 extern int tau_initialized;
 extern int tau_interrupts(int);
 #endif
+#endif /* CONFIG_PPC32 */
 
 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 extern atomic_t ipi_recv;
 extern atomic_t ipi_sent;
 #endif
-#endif /* CONFIG_PPC32 */
 
 #ifdef CONFIG_PPC64
 EXPORT_SYMBOL(irq_desc);
 
 int distribute_irqs = 1;
-u64 ppc64_interrupt_controller;
 #endif /* CONFIG_PPC64 */
 
 int show_interrupts(struct seq_file *p, void *v)
@@ -182,7 +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
@@ -213,22 +217,26 @@ 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();
                 irqtp = hardirq_ctx[smp_processor_id()];
                 if (curtp != irqtp) {
+                        struct irq_desc *desc = irq_desc + irq;
+                        void *handler = desc->handle_irq;
+                        if (handler == NULL)
+                                handler = &__do_IRQ;
                         irqtp->task = curtp->task;
                         irqtp->flags = 0;
-                        call___do_IRQ(irq, regs, irqtp);
+                        call_handle_irq(irq, desc, regs, irqtp, handler);
                         irqtp->task = NULL;
                         if (irqtp->flags)
                                 set_bits(irqtp->flags, &curtp->flags);
                 } else
 #endif
-                        __do_IRQ(irq, regs);
-        } else if (irq != -2)
+                        generic_handle_irq(irq, regs);
+        } else if (irq != NO_IRQ_IGNORE)
                 /* That's not SMP safe ... but who cares ? */
                 ppc_spurious_interrupts++;
 
@@ -245,191 +253,562 @@ void do_IRQ(struct pt_regs *regs)
 
 void __init init_IRQ(void)
 {
+        ppc_md.init_IRQ();
 #ifdef CONFIG_PPC64
-        static int once = 0;
+        irq_ctx_init();
+#endif
+}
+
+
+#ifdef CONFIG_IRQSTACKS
+struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
+struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
+
+void irq_ctx_init(void)
+{
+        struct thread_info *tp;
+        int i;
+
+        for_each_possible_cpu(i) {
+                memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
+                tp = softirq_ctx[i];
+                tp->cpu = i;
+                tp->preempt_count = SOFTIRQ_OFFSET;
+
+                memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
+                tp = hardirq_ctx[i];
+                tp->cpu = i;
+                tp->preempt_count = HARDIRQ_OFFSET;
+        }
+}
+
+static inline void do_softirq_onstack(void)
+{
+        struct thread_info *curtp, *irqtp;
+
+        curtp = current_thread_info();
+        irqtp = softirq_ctx[smp_processor_id()];
+        irqtp->task = curtp->task;
+        call_do_softirq(irqtp);
+        irqtp->task = NULL;
+}
 
-        if (once)
+#else
+#define do_softirq_onstack()    __do_softirq()
+#endif /* CONFIG_IRQSTACKS */
+
+void do_softirq(void)
+{
+        unsigned long flags;
+
+        if (in_interrupt())
                 return;
 
-        once++;
+        local_irq_save(flags);
 
-#endif
-        ppc_md.init_IRQ();
-#ifdef CONFIG_PPC64
-        irq_ctx_init();
-#endif
+        if (local_softirq_pending())
+                do_softirq_onstack();
+
+        local_irq_restore(flags);
 }
+EXPORT_SYMBOL(do_softirq);
+
 
-#ifdef CONFIG_PPC64
 /*
- * Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
+ * IRQ controller and virtual interrupts
  */
 
-#define UNDEFINED_IRQ 0xffffffff
-unsigned int virt_irq_to_real_map[NR_IRQS];
+#ifdef CONFIG_PPC_MERGE
 
-/*
- * 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
+static LIST_HEAD(irq_hosts);
+static spinlock_t irq_big_lock = SPIN_LOCK_UNLOCKED;
 
-unsigned int virt_irq_max;
-static unsigned int max_virt_irq;
-static unsigned int nr_virt_irqs;
+struct irq_map_entry irq_map[NR_IRQS];
+static unsigned int irq_virq_count = NR_IRQS;
+static struct irq_host *irq_default_host;
 
-void
-virt_irq_init(void)
+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)
 {
-        int i;
+        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;
 
-        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;
+        /* Fill structure */
+        host->revmap_type = revmap_type;
+        host->inval_irq = inval_irq;
+        host->ops = ops;
 
-        for (i = 0; i < NR_IRQS; i++)
-                virt_irq_to_real_map[i] = UNDEFINED_IRQ;
+        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;
 }
 
-/* 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)
+struct irq_host *irq_find_host(struct device_node *node)
 {
-        unsigned int virq, first_virq;
-        static int warned;
+        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);
 
-        if (ppc64_interrupt_controller == IC_OPEN_PIC)
-                return real_irq;        /* no mapping for openpic (for now) */
+        irq_default_host = host;
+}
 
-        if (ppc64_interrupt_controller == IC_CELL_PIC)
-                return real_irq;        /* no mapping for iic either */
+void irq_set_virq_count(unsigned int count)
+{
+        pr_debug("irq: Trying to set virq count to %d\n", count);
 
-        /* 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;
+        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);
 
-        /* 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 */
+        /* 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;
         }
 
-        virt_irq_to_real_map[virq] = real_irq;
+        /* 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;
 
- 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;
+        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 NO_IRQ;
+
+        return irq_create_mapping(host, hwirq, flags);
 }
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 
-/*
- * 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 irq_of_parse_and_map(struct device_node *dev, int index)
 {
-        unsigned int virq;
-        unsigned int first_virq;
+        struct of_irq oirq;
 
-        virq = real_irq;
+        if (of_irq_map_one(dev, index, &oirq))
+                return NO_IRQ;
 
-        if (virq > max_virt_irq)
-                virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ;
+        return irq_create_of_mapping(oirq.controller, oirq.specifier,
+                                     oirq.size);
+}
+EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 
-        first_virq = virq;
+void irq_dispose_mapping(unsigned int virq)
+{
+        struct irq_host *host = irq_map[virq].host;
+        irq_hw_number_t hwirq;
+        unsigned long flags;
 
-        do {
-                if (virt_irq_to_real_map[virq] == real_irq)
-                        return virq;
+        WARN_ON (host == NULL);
+        if (host == NULL)
+                return;
 
-                virq++;
+        /* Never unmap legacy interrupts */
+        if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
+                return;
 
-                if (virq >= max_virt_irq)
-                        virq = 0;
+        /* 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;
+        }
 
-        } while (first_virq != virq);
+        /* Destroy map */
+        smp_mb();
+        irq_map[virq].hwirq = host->inval_irq;
 
-        return NO_IRQ;
+        /* Set some flags */
+        get_irq_desc(virq)->status |= IRQ_NOREQUEST;
 
+        /* Free it */
+        irq_free_virt(virq, 1);
 }
-#endif /* CONFIG_PPC64 */
+EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 
-#ifdef CONFIG_IRQSTACKS
-struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
+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);
 
-void irq_ctx_init(void)
+
+unsigned int irq_radix_revmap(struct irq_host *host,
+                              irq_hw_number_t hwirq)
 {
-        struct thread_info *tp;
-        int i;
+        struct radix_tree_root *tree;
+        struct irq_map_entry *ptr;
+        unsigned int virq;
+        unsigned long flags;
 
-        for_each_possible_cpu(i) {
-                memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
-                tp = softirq_ctx[i];
-                tp->cpu = i;
-                tp->preempt_count = SOFTIRQ_OFFSET;
+        WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE);
 
-                memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
-                tp = hardirq_ctx[i];
-                tp->cpu = i;
-                tp->preempt_count = HARDIRQ_OFFSET;
+        /* 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;
 }
 
-static inline void do_softirq_onstack(void)
+unsigned int irq_linear_revmap(struct irq_host *host,
+                               irq_hw_number_t hwirq)
 {
-        struct thread_info *curtp, *irqtp;
+        unsigned int *revmap;
 
-        curtp = current_thread_info();
-        irqtp = softirq_ctx[smp_processor_id()];
-        irqtp->task = curtp->task;
-        call_do_softirq(irqtp);
-        irqtp->task = NULL;
+        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];
 }
 
-#else
-#define do_softirq_onstack()    __do_softirq()
-#endif /* CONFIG_IRQSTACKS */
+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;
 
-void do_softirq(void)
+        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;
 
-        if (in_interrupt())
-                return;
+        WARN_ON (virq < NUM_ISA_INTERRUPTS);
+        WARN_ON (count == 0 || (virq + count) > irq_virq_count);
 
-        local_irq_save(flags);
+        spin_lock_irqsave(&irq_big_lock, flags);
+        for (i = virq; i < (virq + count); i++) {
+                struct irq_host *host;
 
-        if (local_softirq_pending())
-                do_softirq_onstack();
+                if (i < NUM_ISA_INTERRUPTS ||
+                    (virq + count) > irq_virq_count)
+                        continue;
 
-        local_irq_restore(flags);
+                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);
 }
-EXPORT_SYMBOL(do_softirq);
+
+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)