1 files changed, 36 insertions, 0 deletions
diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c
new file mode 100644
index 00000000..2334bf8a
--- /dev/null
+++ b/arch/arm/kernel/pmu.c
@@ -0,0 +1,36 @@
+/*
+ *  linux/arch/arm/kernel/pmu.c
+ *
+ *  Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
+ *  Copyright (C) 2010 ARM Ltd, Will Deacon
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <asm/pmu.h>
+
+/*
+ * PMU locking to ensure mutual exclusion between different subsystems.
+ */
+static unsigned long pmu_lock[BITS_TO_LONGS(ARM_NUM_PMU_DEVICES)];
+
+int
+reserve_pmu(enum arm_pmu_type type)
+{
+	return test_and_set_bit_lock(type, pmu_lock) ? -EBUSY : 0;
+}
+EXPORT_SYMBOL_GPL(reserve_pmu);
+
+void
+release_pmu(enum arm_pmu_type type)
+{
+	clear_bit_unlock(type, pmu_lock);
+}
+EXPORT_SYMBOL_GPL(release_pmu);