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>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 10e06801afb3..9d40c341e07e 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
          */