9 files changed, 428 insertions, 60 deletions

diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 681c52dbfe22..4dd5b1edac98 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -3,3 +3,4 @@ obj-y := handle.o manage.o spurious.o resend.o chip.o devres.o
 obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
+obj-$(CONFIG_NUMA_MIGRATE_IRQ_DESC) += numa_migrate.o
diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c
index cc0f7321b8ce..1de9700f416e 100644
--- a/kernel/irq/autoprobe.c
+++ b/kernel/irq/autoprobe.c
@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
+#include <linux/async.h>
 
 #include "internals.h"
 
@@ -34,6 +35,10 @@ unsigned long probe_irq_on(void)
         unsigned int status;
         int i;
 
+        /*
+         * quiesce the kernel, or at least the asynchronous portion
+         */
+        async_synchronize_full();
         mutex_lock(&probing_active);
         /*
          * something may have generated an irq long ago and we want to
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 10b5092e9bfe..f63c706d25e1 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -24,9 +24,10 @@
  */
 void dynamic_irq_init(unsigned int irq)
 {
-        struct irq_desc *desc = irq_to_desc(irq);
+        struct irq_desc *desc;
         unsigned long flags;
 
+        desc = irq_to_desc(irq);
         if (!desc) {
                 WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
                 return;
@@ -45,7 +46,7 @@ void dynamic_irq_init(unsigned int irq)
         desc->irq_count = 0;
         desc->irqs_unhandled = 0;
 #ifdef CONFIG_SMP
-        cpus_setall(desc->affinity);
+        cpumask_setall(&desc->affinity);
 #endif
         spin_unlock_irqrestore(&desc->lock, flags);
 }
@@ -124,6 +125,7 @@ int set_irq_type(unsigned int irq, unsigned int type)
                 return -ENODEV;
         }
 
+        type &= IRQ_TYPE_SENSE_MASK;
         if (type == IRQ_TYPE_NONE)
                 return 0;
 
@@ -352,6 +354,7 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
 
         spin_lock(&desc->lock);
         mask_ack_irq(desc, irq);
+        desc = irq_remap_to_desc(irq, desc);
 
         if (unlikely(desc->status & IRQ_INPROGRESS))
                 goto out_unlock;
@@ -429,6 +432,7 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
         desc->status &= ~IRQ_INPROGRESS;
 out:
         desc->chip->eoi(irq);
+        desc = irq_remap_to_desc(irq, desc);
 
         spin_unlock(&desc->lock);
 }
@@ -465,12 +469,14 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
                     !desc->action)) {
                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
                 mask_ack_irq(desc, irq);
+                desc = irq_remap_to_desc(irq, desc);
                 goto out_unlock;
         }
         kstat_incr_irqs_this_cpu(irq, desc);
 
         /* Start handling the irq */
         desc->chip->ack(irq);
+        desc = irq_remap_to_desc(irq, desc);
 
         /* Mark the IRQ currently in progress.*/
         desc->status |= IRQ_INPROGRESS;
@@ -531,8 +537,10 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
         if (!noirqdebug)
                 note_interrupt(irq, desc, action_ret);
 
-        if (desc->chip->eoi)
+        if (desc->chip->eoi) {
                 desc->chip->eoi(irq);
+                desc = irq_remap_to_desc(irq, desc);
+        }
 }
 
 void
@@ -567,8 +575,10 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 
         /* Uninstall? */
         if (handle == handle_bad_irq) {
-                if (desc->chip != &no_irq_chip)
+                if (desc->chip != &no_irq_chip) {
                         mask_ack_irq(desc, irq);
+                        desc = irq_remap_to_desc(irq, desc);
+                }
                 desc->status |= IRQ_DISABLED;
                 desc->depth = 1;
         }
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index c815b42d0f5b..c20db0be9173 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -15,9 +15,16 @@
 #include <linux/random.h>
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
+#include <linux/rculist.h>
+#include <linux/hash.h>
 
 #include "internals.h"
 
+/*
+ * lockdep: we want to handle all irq_desc locks as a single lock-class:
+ */
+struct lock_class_key irq_desc_lock_class;
+
 /**
  * handle_bad_irq - handle spurious and unhandled irqs
  * @irq:       the interrupt number
@@ -49,6 +56,150 @@ void handle_bad_irq(unsigned int irq, struct irq_desc *desc)
 int nr_irqs = NR_IRQS;
 EXPORT_SYMBOL_GPL(nr_irqs);
 
+#ifdef CONFIG_SPARSE_IRQ
+static struct irq_desc irq_desc_init = {
+        .irq        = -1,
+        .status     = IRQ_DISABLED,
+        .chip       = &no_irq_chip,
+        .handle_irq = handle_bad_irq,
+        .depth      = 1,
+        .lock       = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
+#ifdef CONFIG_SMP
+        .affinity   = CPU_MASK_ALL
+#endif
+};
+
+void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
+{
+        unsigned long bytes;
+        char *ptr;
+        int node;
+
+        /* Compute how many bytes we need per irq and allocate them */
+        bytes = nr * sizeof(unsigned int);
+
+        node = cpu_to_node(cpu);
+        ptr = kzalloc_node(bytes, GFP_ATOMIC, node);
+        printk(KERN_DEBUG "  alloc kstat_irqs on cpu %d node %d\n", cpu, node);
+
+        if (ptr)
+                desc->kstat_irqs = (unsigned int *)ptr;
+}
+
+static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu)
+{
+        memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
+
+        spin_lock_init(&desc->lock);
+        desc->irq = irq;
+#ifdef CONFIG_SMP
+        desc->cpu = cpu;
+#endif
+        lockdep_set_class(&desc->lock, &irq_desc_lock_class);
+        init_kstat_irqs(desc, cpu, nr_cpu_ids);
+        if (!desc->kstat_irqs) {
+                printk(KERN_ERR "can not alloc kstat_irqs\n");
+                BUG_ON(1);
+        }
+        arch_init_chip_data(desc, cpu);
+}
+
+/*
+ * Protect the sparse_irqs:
+ */
+DEFINE_SPINLOCK(sparse_irq_lock);
+
+struct irq_desc *irq_desc_ptrs[NR_IRQS] __read_mostly;
+
+static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = {
+        [0 ... NR_IRQS_LEGACY-1] = {
+                .irq        = -1,
+                .status     = IRQ_DISABLED,
+                .chip       = &no_irq_chip,
+                .handle_irq = handle_bad_irq,
+                .depth      = 1,
+                .lock       = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
+#ifdef CONFIG_SMP
+                .affinity   = CPU_MASK_ALL
+#endif
+        }
+};
+
+/* FIXME: use bootmem alloc ...*/
+static unsigned int kstat_irqs_legacy[NR_IRQS_LEGACY][NR_CPUS];
+
+int __init early_irq_init(void)
+{
+        struct irq_desc *desc;
+        int legacy_count;
+        int i;
+
+        desc = irq_desc_legacy;
+        legacy_count = ARRAY_SIZE(irq_desc_legacy);
+
+        for (i = 0; i < legacy_count; i++) {
+                desc[i].irq = i;
+                desc[i].kstat_irqs = kstat_irqs_legacy[i];
+                lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
+
+                irq_desc_ptrs[i] = desc + i;
+        }
+
+        for (i = legacy_count; i < NR_IRQS; i++)
+                irq_desc_ptrs[i] = NULL;
+
+        return arch_early_irq_init();
+}
+
+struct irq_desc *irq_to_desc(unsigned int irq)
+{
+        return (irq < NR_IRQS) ? irq_desc_ptrs[irq] : NULL;
+}
+
+struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
+{
+        struct irq_desc *desc;
+        unsigned long flags;
+        int node;
+
+        if (irq >= NR_IRQS) {
+                printk(KERN_WARNING "irq >= NR_IRQS in irq_to_desc_alloc: %d %d\n",
+                                irq, NR_IRQS);
+                WARN_ON(1);
+                return NULL;
+        }
+
+        desc = irq_desc_ptrs[irq];
+        if (desc)
+                return desc;
+
+        spin_lock_irqsave(&sparse_irq_lock, flags);
+
+        /* We have to check it to avoid races with another CPU */
+        desc = irq_desc_ptrs[irq];
+        if (desc)
+                goto out_unlock;
+
+        node = cpu_to_node(cpu);
+        desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
+        printk(KERN_DEBUG "  alloc irq_desc for %d on cpu %d node %d\n",
+                 irq, cpu, node);
+        if (!desc) {
+                printk(KERN_ERR "can not alloc irq_desc\n");
+                BUG_ON(1);
+        }
+        init_one_irq_desc(irq, desc, cpu);
+
+        irq_desc_ptrs[irq] = desc;
+
+out_unlock:
+        spin_unlock_irqrestore(&sparse_irq_lock, flags);
+
+        return desc;
+}
+
+#else /* !CONFIG_SPARSE_IRQ */
+
 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
         [0 ... NR_IRQS-1] = {
                 .status = IRQ_DISABLED,
@@ -62,6 +213,32 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
         }
 };
 
+int __init early_irq_init(void)
+{
+        struct irq_desc *desc;
+        int count;
+        int i;
+
+        desc = irq_desc;
+        count = ARRAY_SIZE(irq_desc);
+
+        for (i = 0; i < count; i++)
+                desc[i].irq = i;
+
+        return arch_early_irq_init();
+}
+
+struct irq_desc *irq_to_desc(unsigned int irq)
+{
+        return (irq < NR_IRQS) ? irq_desc + irq : NULL;
+}
+
+struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
+{
+        return irq_to_desc(irq);
+}
+#endif /* !CONFIG_SPARSE_IRQ */
+
 /*
  * What should we do if we get a hw irq event on an illegal vector?
  * Each architecture has to answer this themself.
@@ -179,8 +356,11 @@ unsigned int __do_IRQ(unsigned int irq)
                 /*
                  * No locking required for CPU-local interrupts:
                  */
-                if (desc->chip->ack)
+                if (desc->chip->ack) {
                         desc->chip->ack(irq);
+                        /* get new one */
+                        desc = irq_remap_to_desc(irq, desc);
+                }
                 if (likely(!(desc->status & IRQ_DISABLED))) {
                         action_ret = handle_IRQ_event(irq, desc->action);
                         if (!noirqdebug)
@@ -191,8 +371,10 @@ unsigned int __do_IRQ(unsigned int irq)
         }
 
         spin_lock(&desc->lock);
-        if (desc->chip->ack)
+        if (desc->chip->ack) {
                 desc->chip->ack(irq);
+                desc = irq_remap_to_desc(irq, desc);
+        }
         /*
          * REPLAY is when Linux resends an IRQ that was dropped earlier
          * WAITING is used by probe to mark irqs that are being tested
@@ -259,19 +441,22 @@ out:
 }
 #endif
 
-
-#ifdef CONFIG_TRACE_IRQFLAGS
-/*
- * lockdep: we want to handle all irq_desc locks as a single lock-class:
- */
-static struct lock_class_key irq_desc_lock_class;
-
 void early_init_irq_lock_class(void)
 {
         struct irq_desc *desc;
         int i;
 
-        for_each_irq_desc(i, desc)
+        for_each_irq_desc(i, desc) {
                 lockdep_set_class(&desc->lock, &irq_desc_lock_class);
+        }
+}
+
+#ifdef CONFIG_SPARSE_IRQ
+unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+        return desc ? desc->kstat_irqs[cpu] : 0;
 }
 #endif
+EXPORT_SYMBOL(kstat_irqs_cpu);
+
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 64c1c7253dae..e6d0a43cc125 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -13,6 +13,11 @@ extern void compat_irq_chip_set_default_handler(struct irq_desc *desc);
 extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
                 unsigned long flags);
 
+extern struct lock_class_key irq_desc_lock_class;
+extern void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr);
+extern spinlock_t sparse_irq_lock;
+extern struct irq_desc *irq_desc_ptrs[NR_IRQS];
+
 #ifdef CONFIG_PROC_FS
 extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
 extern void register_handler_proc(unsigned int irq, struct irqaction *action);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 801addda3c43..cd0cd8dcb345 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -16,8 +16,15 @@
 #include "internals.h"
 
 #ifdef CONFIG_SMP
+cpumask_var_t irq_default_affinity;
 
-cpumask_t irq_default_affinity = CPU_MASK_ALL;
+static int init_irq_default_affinity(void)
+{
+        alloc_cpumask_var(&irq_default_affinity, GFP_KERNEL);
+        cpumask_setall(irq_default_affinity);
+        return 0;
+}
+core_initcall(init_irq_default_affinity);
 
 /**
  *      synchronize_irq - wait for pending IRQ handlers (on other CPUs)
@@ -79,7 +86,7 @@ int irq_can_set_affinity(unsigned int irq)
  *      @cpumask:       cpumask
  *
  */
-int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
+int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 {
         struct irq_desc *desc = irq_to_desc(irq);
         unsigned long flags;
@@ -91,14 +98,14 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
         if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
-                desc->affinity = cpumask;
+                cpumask_copy(&desc->affinity, cpumask);
                 desc->chip->set_affinity(irq, cpumask);
         } else {
                 desc->status |= IRQ_MOVE_PENDING;
-                desc->pending_mask = cpumask;
+                cpumask_copy(&desc->pending_mask, cpumask);
         }
 #else
-        desc->affinity = cpumask;
+        cpumask_copy(&desc->affinity, cpumask);
         desc->chip->set_affinity(irq, cpumask);
 #endif
         desc->status |= IRQ_AFFINITY_SET;
@@ -112,26 +119,24 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
  */
 int do_irq_select_affinity(unsigned int irq, struct irq_desc *desc)
 {
-        cpumask_t mask;
-
         if (!irq_can_set_affinity(irq))
                 return 0;
 
-        cpus_and(mask, cpu_online_map, irq_default_affinity);
-
         /*
          * Preserve an userspace affinity setup, but make sure that
          * one of the targets is online.
          */
         if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) {
-                if (cpus_intersects(desc->affinity, cpu_online_map))
-                        mask = desc->affinity;
+                if (cpumask_any_and(&desc->affinity, cpu_online_mask)
+                    < nr_cpu_ids)
+                        goto set_affinity;
                 else
                         desc->status &= ~IRQ_AFFINITY_SET;
         }
 
-        desc->affinity = mask;
-        desc->chip->set_affinity(irq, mask);
+        cpumask_and(&desc->affinity, cpu_online_mask, irq_default_affinity);
+set_affinity:
+        desc->chip->set_affinity(irq, &desc->affinity);
 
         return 0;
 }
@@ -370,16 +375,18 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
                 return 0;
         }
 
-        ret = chip->set_type(irq, flags & IRQF_TRIGGER_MASK);
+        /* caller masked out all except trigger mode flags */
+        ret = chip->set_type(irq, flags);
 
         if (ret)
                 pr_err("setting trigger mode %d for irq %u failed (%pF)\n",
-                                (int)(flags & IRQF_TRIGGER_MASK),
-                                irq, chip->set_type);
+                                (int)flags, irq, chip->set_type);
         else {
+                if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
+                        flags |= IRQ_LEVEL;
                 /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */
-                desc->status &= ~IRQ_TYPE_SENSE_MASK;
-                desc->status |= flags & IRQ_TYPE_SENSE_MASK;
+                desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK);
+                desc->status |= flags;
         }
 
         return ret;
@@ -459,7 +466,8 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
 
                 /* Setup the type (level, edge polarity) if configured: */
                 if (new->flags & IRQF_TRIGGER_MASK) {
-                        ret = __irq_set_trigger(desc, irq, new->flags);
+                        ret = __irq_set_trigger(desc, irq,
+                                        new->flags & IRQF_TRIGGER_MASK);
 
                         if (ret) {
                                 spin_unlock_irqrestore(&desc->lock, flags);
@@ -673,6 +681,18 @@ int request_irq(unsigned int irq, irq_handler_t handler,
         struct irq_desc *desc;
         int retval;
 
+        /*
+         * handle_IRQ_event() always ignores IRQF_DISABLED except for
+         * the _first_ irqaction (sigh).  That can cause oopsing, but
+         * the behavior is classified as "will not fix" so we need to
+         * start nudging drivers away from using that idiom.
+         */
+        if ((irqflags & (IRQF_SHARED|IRQF_DISABLED))
+                        == (IRQF_SHARED|IRQF_DISABLED))
+                pr_warning("IRQ %d/%s: IRQF_DISABLED is not "
+                                "guaranteed on shared IRQs\n",
+                                irq, devname);
+
 #ifdef CONFIG_LOCKDEP
         /*
          * Lockdep wants atomic interrupt handlers:
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index 9db681d95814..bd72329e630c 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -4,7 +4,6 @@
 void move_masked_irq(int irq)
 {
         struct irq_desc *desc = irq_to_desc(irq);
-        cpumask_t tmp;
 
         if (likely(!(desc->status & IRQ_MOVE_PENDING)))
                 return;
@@ -19,7 +18,7 @@ void move_masked_irq(int irq)
 
         desc->status &= ~IRQ_MOVE_PENDING;
 
-        if (unlikely(cpus_empty(desc->pending_mask)))
+        if (unlikely(cpumask_empty(&desc->pending_mask)))
                 return;
 
         if (!desc->chip->set_affinity)
@@ -27,8 +26,6 @@ void move_masked_irq(int irq)
 
         assert_spin_locked(&desc->lock);
 
-        cpus_and(tmp, desc->pending_mask, cpu_online_map);
-
         /*
          * If there was a valid mask to work with, please
          * do the disable, re-program, enable sequence.
@@ -41,10 +38,13 @@ void move_masked_irq(int irq)
          * For correct operation this depends on the caller
          * masking the irqs.
          */
-        if (likely(!cpus_empty(tmp))) {
-                desc->chip->set_affinity(irq,tmp);
+        if (likely(cpumask_any_and(&desc->pending_mask, cpu_online_mask)
+                   < nr_cpu_ids)) {
+                cpumask_and(&desc->affinity,
+                            &desc->pending_mask, cpu_online_mask);
+                desc->chip->set_affinity(irq, &desc->affinity);
         }
-        cpus_clear(desc->pending_mask);
+        cpumask_clear(&desc->pending_mask);
 }
 
 void move_native_irq(int irq)
diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
new file mode 100644
index 000000000000..ecf765c6a77a
--- /dev/null
+++ b/kernel/irq/numa_migrate.c
@@ -0,0 +1,119 @@
+/*
+ * NUMA irq-desc migration code
+ *
+ * Migrate IRQ data structures (irq_desc, chip_data, etc.) over to
+ * the new "home node" of the IRQ.
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+
+#include "internals.h"
+
+static void init_copy_kstat_irqs(struct irq_desc *old_desc,
+                                 struct irq_desc *desc,
+                                 int cpu, int nr)
+{
+        unsigned long bytes;
+
+        init_kstat_irqs(desc, cpu, nr);
+
+        if (desc->kstat_irqs != old_desc->kstat_irqs) {
+                /* Compute how many bytes we need per irq and allocate them */
+                bytes = nr * sizeof(unsigned int);
+
+                memcpy(desc->kstat_irqs, old_desc->kstat_irqs, bytes);
+        }
+}
+
+static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc)
+{
+        if (old_desc->kstat_irqs == desc->kstat_irqs)
+                return;
+
+        kfree(old_desc->kstat_irqs);
+        old_desc->kstat_irqs = NULL;
+}
+
+static void init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
+                 struct irq_desc *desc, int cpu)
+{
+        memcpy(desc, old_desc, sizeof(struct irq_desc));
+        spin_lock_init(&desc->lock);
+        desc->cpu = cpu;
+        lockdep_set_class(&desc->lock, &irq_desc_lock_class);
+        init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
+        arch_init_copy_chip_data(old_desc, desc, cpu);
+}
+
+static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
+{
+        free_kstat_irqs(old_desc, desc);
+        arch_free_chip_data(old_desc, desc);
+}
+
+static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
+                                                int cpu)
+{
+        struct irq_desc *desc;
+        unsigned int irq;
+        unsigned long flags;
+        int node;
+
+        irq = old_desc->irq;
+
+        spin_lock_irqsave(&sparse_irq_lock, flags);
+
+        /* We have to check it to avoid races with another CPU */
+        desc = irq_desc_ptrs[irq];
+
+        if (desc && old_desc != desc)
+                        goto out_unlock;
+
+        node = cpu_to_node(cpu);
+        desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
+        if (!desc) {
+                printk(KERN_ERR "irq %d: can not get new irq_desc for migration.\n", irq);
+                /* still use old one */
+                desc = old_desc;
+                goto out_unlock;
+        }
+        init_copy_one_irq_desc(irq, old_desc, desc, cpu);
+
+        irq_desc_ptrs[irq] = desc;
+
+        /* free the old one */
+        free_one_irq_desc(old_desc, desc);
+        kfree(old_desc);
+
+out_unlock:
+        spin_unlock_irqrestore(&sparse_irq_lock, flags);
+
+        return desc;
+}
+
+struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu)
+{
+        int old_cpu;
+        int node, old_node;
+
+        /* those all static, do move them */
+        if (desc->irq < NR_IRQS_LEGACY)
+                return desc;
+
+        old_cpu = desc->cpu;
+        if (old_cpu != cpu) {
+                node = cpu_to_node(cpu);
+                old_node = cpu_to_node(old_cpu);
+                if (old_node != node)
+                        desc = __real_move_irq_desc(desc, cpu);
+                else
+                        desc->cpu = cpu;
+        }
+
+        return desc;
+}
+
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index d257e7d6a8a4..aae3f742bcec 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -20,7 +20,7 @@ static struct proc_dir_entry *root_irq_dir;
 static int irq_affinity_proc_show(struct seq_file *m, void *v)
 {
         struct irq_desc *desc = irq_to_desc((long)m->private);
-        cpumask_t *mask = &desc->affinity;
+        const struct cpumask *mask = &desc->affinity;
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
         if (desc->status & IRQ_MOVE_PENDING)
@@ -40,33 +40,42 @@ static ssize_t irq_affinity_proc_write(struct file *file,
                 const char __user *buffer, size_t count, loff_t *pos)
 {
         unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
-        cpumask_t new_value;
+        cpumask_var_t new_value;
         int err;
 
         if (!irq_to_desc(irq)->chip->set_affinity || no_irq_affinity ||
             irq_balancing_disabled(irq))
                 return -EIO;
 
+        if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
+                return -ENOMEM;
+
         err = cpumask_parse_user(buffer, count, new_value);
         if (err)
-                return err;
+                goto free_cpumask;
 
-        if (!is_affinity_mask_valid(new_value))
-                return -EINVAL;
+        if (!is_affinity_mask_valid(new_value)) {
+                err = -EINVAL;
+                goto free_cpumask;
+        }
 
         /*
          * Do not allow disabling IRQs completely - it's a too easy
          * way to make the system unusable accidentally :-) At least
          * one online CPU still has to be targeted.
          */
-        if (!cpus_intersects(new_value, cpu_online_map))
+        if (!cpumask_intersects(new_value, cpu_online_mask)) {
                 /* Special case for empty set - allow the architecture
                    code to set default SMP affinity. */
-                return irq_select_affinity_usr(irq) ? -EINVAL : count;
-
-        irq_set_affinity(irq, new_value);
+                err = irq_select_affinity_usr(irq) ? -EINVAL : count;
+        } else {
+                irq_set_affinity(irq, new_value);
+                err = count;
+        }
 
-        return count;
+free_cpumask:
+        free_cpumask_var(new_value);
+        return err;
 }
 
 static int irq_affinity_proc_open(struct inode *inode, struct file *file)
@@ -84,7 +93,7 @@ static const struct file_operations irq_affinity_proc_fops = {
 
 static int default_affinity_show(struct seq_file *m, void *v)
 {
-        seq_cpumask(m, &irq_default_affinity);
+        seq_cpumask(m, irq_default_affinity);
         seq_putc(m, '\n');
         return 0;
 }
@@ -92,27 +101,37 @@ static int default_affinity_show(struct seq_file *m, void *v)
 static ssize_t default_affinity_write(struct file *file,
                 const char __user *buffer, size_t count, loff_t *ppos)
 {
-        cpumask_t new_value;
+        cpumask_var_t new_value;
         int err;
 
+        if (!alloc_cpumask_var(&new_value, GFP_KERNEL))
+                return -ENOMEM;
+
         err = cpumask_parse_user(buffer, count, new_value);
         if (err)
-                return err;
+                goto out;
 
-        if (!is_affinity_mask_valid(new_value))
-                return -EINVAL;
+        if (!is_affinity_mask_valid(new_value)) {
+                err = -EINVAL;
+                goto out;
+        }
 
         /*
          * Do not allow disabling IRQs completely - it's a too easy
          * way to make the system unusable accidentally :-) At least
          * one online CPU still has to be targeted.
          */
-        if (!cpus_intersects(new_value, cpu_online_map))
-                return -EINVAL;
+        if (!cpumask_intersects(new_value, cpu_online_mask)) {
+                err = -EINVAL;
+                goto out;
+        }
 
-        irq_default_affinity = new_value;
+        cpumask_copy(irq_default_affinity, new_value);
+        err = count;
 
-        return count;
+out:
+        free_cpumask_var(new_value);
+        return err;
 }
 
 static int default_affinity_open(struct inode *inode, struct file *file)
@@ -243,7 +262,11 @@ void init_irq_proc(void)
         /*
          * Create entries for all existing IRQs.
          */
-        for_each_irq_desc(irq, desc)
+        for_each_irq_desc(irq, desc) {
+                if (!desc)
+                        continue;
+
                 register_irq_proc(irq, desc);
+        }
 }