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authorJamie Iles <jamie.iles@picochip.com>2010-02-02 20:23:15 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-02-12 17:23:43 +0000
commit0f4f0672ac950c96cffaf84a666d35e817d7c3ca (patch)
treecb4c1ec72f7842622c636a76f5ca519f3f3e8ea8 /arch/arm/include/asm/pmu.h
parent74d2e4f8d79ae0c4b6ec027958d5b18058662eea (diff)
ARM: 5899/2: arm: provide a mechanism to reserve performance counters
To add support for perf events and to allow the hardware counters to be shared with oprofile, we need a way to reserve access to the pmu (performance monitor unit). Platforms with PMU interrupts should register the interrupts in arch/arm/kernel/pmu.c Signed-off-by: Jamie Iles <jamie.iles@picochip.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/pmu.h')
-rw-r--r--arch/arm/include/asm/pmu.h75
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/arm/include/asm/pmu.h b/arch/arm/include/asm/pmu.h
new file mode 100644
index 00000000000..2829b9f981a
--- /dev/null
+++ b/arch/arm/include/asm/pmu.h
@@ -0,0 +1,75 @@
+/*
+ * linux/arch/arm/include/asm/pmu.h
+ *
+ * Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
+ *
+ * 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.
+ *
+ */
+
+#ifndef __ARM_PMU_H__
+#define __ARM_PMU_H__
+
+#ifdef CONFIG_CPU_HAS_PMU
+
+struct pmu_irqs {
+ const int *irqs;
+ int num_irqs;
+};
+
+/**
+ * reserve_pmu() - reserve the hardware performance counters
+ *
+ * Reserve the hardware performance counters in the system for exclusive use.
+ * The 'struct pmu_irqs' for the system is returned on success, ERR_PTR()
+ * encoded error on failure.
+ */
+extern const struct pmu_irqs *
+reserve_pmu(void);
+
+/**
+ * release_pmu() - Relinquish control of the performance counters
+ *
+ * Release the performance counters and allow someone else to use them.
+ * Callers must have disabled the counters and released IRQs before calling
+ * this. The 'struct pmu_irqs' returned from reserve_pmu() must be passed as
+ * a cookie.
+ */
+extern int
+release_pmu(const struct pmu_irqs *irqs);
+
+/**
+ * init_pmu() - Initialise the PMU.
+ *
+ * Initialise the system ready for PMU enabling. This should typically set the
+ * IRQ affinity and nothing else. The users (oprofile/perf events etc) will do
+ * the actual hardware initialisation.
+ */
+extern int
+init_pmu(void);
+
+#else /* CONFIG_CPU_HAS_PMU */
+
+static inline const struct pmu_irqs *
+reserve_pmu(void)
+{
+ return ERR_PTR(-ENODEV);
+}
+
+static inline int
+release_pmu(const struct pmu_irqs *irqs)
+{
+ return -ENODEV;
+}
+
+static inline int
+init_pmu(void)
+{
+ return -ENODEV;
+}
+
+#endif /* CONFIG_CPU_HAS_PMU */
+
+#endif /* __ARM_PMU_H__ */