arm64: reduce el2_setup branching (3ad47d05) · Commits · 戴 / test

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 <marc.zyngier@arm.com> Signed-off-by:

Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by:

Catalin Marinas <catalin.marinas@arm.com>

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,

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