diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2014-08-28 13:08:14 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2014-09-26 14:39:54 +0100 |
| commit | 195b58add463f697fb802ed55e26759094d40a54 (patch) | |
| tree | d3523c21a3bb610a87672356770a83c1e3c0ca8d /arch/arm/kernel/entry-common.S | |
| parent | 8b521cb2947d8811b4cf7fc6a7a6ebde35218243 (diff) | |
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 <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 2 |
1 files changed, 1 insertions, 1 deletions
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 |