From 7ada189f5c8627662c23f49b3e68463f86fc511e Mon Sep 17 00:00:00 2001
From: Jamie Iles <jamie.iles@picochip.com>
Date: Tue, 2 Feb 2010 20:24:58 +0100
Subject: [PATCH] ARM: 5900/2: arm: enable support for software perf events
The perf events subsystem allows counting of both hardware and
software events. This patch implements the bare minimum for software
performance events.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/Kconfig | 2 ++
arch/arm/include/asm/perf_event.h | 31 +++++++++++++++++++++++++++++++
arch/arm/mm/fault.c | 7 +++++++
3 files changed, 40 insertions(+)
create mode 100644 arch/arm/include/asm/perf_event.h
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 9e08891062bfb2..74d1e767f0b703 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -18,6 +18,8 @@ config ARM
select HAVE_KRETPROBES if (HAVE_KPROBES)
select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
select HAVE_GENERIC_DMA_COHERENT
+ select HAVE_PERF_EVENTS
+ select PERF_USE_VMALLOC
help
The ARM series is a line of low-power-consumption RISC chip designs
licensed by ARM Ltd and targeted at embedded applications and
diff --git a/arch/arm/include/asm/perf_event.h b/arch/arm/include/asm/perf_event.h
new file mode 100644
index 00000000000000..49e3049aba32c8
--- /dev/null
+++ b/arch/arm/include/asm/perf_event.h
@@ -0,0 +1,31 @@
+/*
+ * linux/arch/arm/include/asm/perf_event.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_PERF_EVENT_H__
+#define __ARM_PERF_EVENT_H__
+
+/*
+ * NOP: on *most* (read: all supported) ARM platforms, the performance
+ * counter interrupts are regular interrupts and not an NMI. This
+ * means that when we receive the interrupt we can call
+ * perf_event_do_pending() that handles all of the work with
+ * interrupts enabled.
+ */
+static inline void
+set_perf_event_pending(void)
+{
+}
+
+/* ARM performance counters start from 1 (in the cp15 accesses) so use the
+ * same indexes here for consistency. */
+#define PERF_EVENT_INDEX_OFFSET 1
+
+#endif /* __ARM_PERF_EVENT_H__ */
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 10e06801afb38e..9d40c341e07e58 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -18,6 +18,7 @@
#include <linux/page-flags.h>
#include <linux/sched.h>
#include <linux/highmem.h>
+#include <linux/perf_event.h>
#include <asm/system.h>
#include <asm/pgtable.h>
@@ -302,6 +303,12 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
fault = __do_page_fault(mm, addr, fsr, tsk);
up_read(&mm->mmap_sem);
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, addr);
+ if (fault & VM_FAULT_MAJOR)
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0, regs, addr);
+ else if (fault & VM_FAULT_MINOR)
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0, regs, addr);
+
/*
* Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR
*/
--
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