From 195b58add463f697fb802ed55e26759094d40a54 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 28 Aug 2014 13:08:14 +0100 Subject: ARM: Avoid writing to control register on every exception If we are not changing the control register value, avoid writing to it. Writes to the control register can be very expensive, taking around a hundred cycles or so. Signed-off-by: Russell King --- arch/arm/kernel/entry-common.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/kernel/entry-common.S') diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index e52fe5a2d843..6bb09d4abdea 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -366,7 +366,7 @@ ENTRY(vector_swi) str r0, [sp, #S_OLD_R0] @ Save OLD_R0 #endif zero_fp - alignment_trap ip, __cr_alignment + alignment_trap r10, ip, __cr_alignment enable_irq ct_user_exit get_thread_info tsk -- cgit