arm64: Performance counters support

This patch adds support for the AArch64 performance counters.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

arch/arm64/include/asm/perf_event.h

+/*
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ASM_PERF_EVENT_H
+#define __ASM_PERF_EVENT_H
+
+/* It's quiet around here... */
+
+#endif

arch/arm64/include/asm/pmu.h

+/*
+ * Based on arch/arm/include/asm/pmu.h
+ *
+ * Copyright (C) 2009 picoChip Designs Ltd, Jamie Iles
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ASM_PMU_H
+#define __ASM_PMU_H
+
+#ifdef CONFIG_HW_PERF_EVENTS
+
+/* The events for a given PMU register set. */
+struct pmu_hw_events {
+	/*
+	 * The events that are active on the PMU for the given index.
+	 */
+	struct perf_event	**events;
+
+	/*
+	 * A 1 bit for an index indicates that the counter is being used for
+	 * an event. A 0 means that the counter can be used.
+	 */
+	unsigned long           *used_mask;
+
+	/*
+	 * Hardware lock to serialize accesses to PMU registers. Needed for the
+	 * read/modify/write sequences.
+	 */
+	raw_spinlock_t		pmu_lock;
+};
+
+struct arm_pmu {
+	struct pmu		pmu;
+	cpumask_t		active_irqs;
+	const char		*name;
+	irqreturn_t		(*handle_irq)(int irq_num, void *dev);
+	void			(*enable)(struct hw_perf_event *evt, int idx);
+	void			(*disable)(struct hw_perf_event *evt, int idx);
+	int			(*get_event_idx)(struct pmu_hw_events *hw_events,
+						 struct hw_perf_event *hwc);
+	int			(*set_event_filter)(struct hw_perf_event *evt,
+						    struct perf_event_attr *attr);
+	u32			(*read_counter)(int idx);
+	void			(*write_counter)(int idx, u32 val);
+	void			(*start)(void);
+	void			(*stop)(void);
+	void			(*reset)(void *);
+	int			(*map_event)(struct perf_event *event);
+	int			num_events;
+	atomic_t		active_events;
+	struct mutex		reserve_mutex;
+	u64			max_period;
+	struct platform_device	*plat_device;
+	struct pmu_hw_events	*(*get_hw_events)(void);
+};
+
+#define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu))
+
+int __init armpmu_register(struct arm_pmu *armpmu, char *name, int type);
+
+u64 armpmu_event_update(struct perf_event *event,
+			struct hw_perf_event *hwc,
+			int idx);
+
+int armpmu_event_set_period(struct perf_event *event,
+			    struct hw_perf_event *hwc,
+			    int idx);
+
+#endif /* CONFIG_HW_PERF_EVENTS */
+#endif /* __ASM_PMU_H */

tools/perf/perf.h

@@ -88,6 +88,12 @@ void get_term_dimensions(struct winsize *ws);
 #define CPUINFO_PROC	"Processor"
 #endif
 
+#ifdef __aarch64__
+#include "../../arch/arm64/include/asm/unistd.h"
+#define rmb()		asm volatile("dmb ld" ::: "memory")
+#define cpu_relax()	asm volatile("yield" ::: "memory")
+#endif
+
 #ifdef __mips__
 #include "../../arch/mips/include/asm/unistd.h"
 #define rmb()		asm volatile(					\