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Commit 3ad47d05 authored by Mark Rutland's avatar Mark Rutland Committed by Catalin Marinas
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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: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent fda89d9e

arch/arm64/kernel/head.S

+7 −8
Original line number Diff line number Diff line
@@ -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,