From 3ad47d055aa88d9f4189253f5b5c485f4c4626b2 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Wed, 15 Feb 2017 14:54:16 +0000 Subject: [PATCH] arm64: reduce el2_setup branching The early el2_setup code is a little convoluted, with two branches where one would do. This makes the code more painful to read than is necessary. We can remove a branch and simplify the logic by moving the early return in the booted-at-EL1 case earlier in the function. This separates it from all the setup logic that only makes sense for EL2. Acked-by: Marc Zyngier Signed-off-by: Mark Rutland Cc: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/kernel/head.S | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 4fb6ccd886d1..2c3733408c0d 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -534,13 +534,8 @@ ENTRY(kimage_vaddr) ENTRY(el2_setup) mrs x0, CurrentEL cmp x0, #CurrentEL_EL2 - b.ne 1f - mrs x0, sctlr_el2 -CPU_BE( orr x0, x0, #(1 << 25) ) // Set the EE bit for EL2 -CPU_LE( bic x0, x0, #(1 << 25) ) // Clear the EE bit for EL2 - msr sctlr_el2, x0 - b 2f -1: mrs x0, sctlr_el1 + b.eq 1f + mrs x0, sctlr_el1 CPU_BE( orr x0, x0, #(3 << 24) ) // Set the EE and E0E bits for EL1 CPU_LE( bic x0, x0, #(3 << 24) ) // Clear the EE and E0E bits for EL1 msr sctlr_el1, x0 @@ -548,7 +543,11 @@ CPU_LE( bic x0, x0, #(3 << 24) ) // Clear the EE and E0E bits for EL1 isb ret -2: +1: mrs x0, sctlr_el2 +CPU_BE( orr x0, x0, #(1 << 25) ) // Set the EE bit for EL2 +CPU_LE( bic x0, x0, #(1 << 25) ) // Clear the EE bit for EL2 + msr sctlr_el2, x0 + #ifdef CONFIG_ARM64_VHE /* * Check for VHE being present. For the rest of the EL2 setup, -- 2.39.5