1 files changed, 119 insertions, 0 deletions

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;
+}
+