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path: root/kernel/irq/numa_migrate.c
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Diffstat (limited to 'kernel/irq/numa_migrate.c')
-rw-r--r--kernel/irq/numa_migrate.c122
1 files changed, 122 insertions, 0 deletions
diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
new file mode 100644
index 00000000000..089c3746358
--- /dev/null
+++ b/kernel/irq/numa_migrate.c
@@ -0,0 +1,122 @@
+/*
+ * 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));
+ 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);
+ printk(KERN_DEBUG " move irq_desc for %d to cpu %d node %d\n",
+ irq, cpu, node);
+ if (!desc) {
+ printk(KERN_ERR "can not get new irq_desc for moving\n");
+ /* 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;
+ printk(KERN_DEBUG
+ "try to move irq_desc from cpu %d to %d\n", old_cpu, 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;
+}
+