ARM: 6786/1: enable CONFIG_KTIME_SCALAR

Use straight 64-bit values as 64-bit operations are fairly efficient on ARM.
Comparing the asm output with and without KTIME_SCALAR, using 64-bit math
generates clearly better code.

Comparing kernel/hrtimer.c .text size, it goes from 0x1414 to 0x119c with
this change.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ef41f7e39f69..2fec7073f687 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -63,6 +63,10 @@ config GENERIC_CLOCKEVENTS_BROADCAST
         depends on GENERIC_CLOCKEVENTS
         default y if SMP
 
+config KTIME_SCALAR
+        bool
+        default y
+
 config HAVE_TCM
         bool
         select GENERIC_ALLOCATOR