[RFC PATCH 1/3] arm64: entry: Remove unnecessary calculation for S_SP in EL1h

From: Jungseok Lee
Date: Fri Sep 04 2015 - 10:24:32 EST

Under EL1h, S_SP data is not seen in kernel_exit. Thus, x21 calculation
is not needed in kernel_entry. Currently, S_SP information is vaild only
when sp_el0 is used.

Signed-off-by: Jungseok Lee <jungseoklee85@xxxxxxxxx>
arch/arm64/kernel/entry.S | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index e163518..d23ca0d 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -91,8 +91,6 @@
get_thread_info tsk // Ensure MDSCR_EL1.SS is clear,
ldr x19, [tsk, #TI_FLAGS] // since we can unmask debug
disable_step_tsk x19, x20 // exceptions when scheduling.
- .else
- add x21, sp, #S_FRAME_SIZE
mrs x22, elr_el1
mrs x23, spsr_el1

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