linux-kernel - [PATCH v2 05/21] arm64: KVM: VHE: Turn VTCR

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Message-Id: <1453737235-16522-6-git-send-email-marc.zyngier@arm.com>
Date:	Mon, 25 Jan 2016 15:53:39 +0000
From:	Marc Zyngier <marc.zyngier@....com>
To:	Catalin Marinas <catalin.marinas@....com>,
	Will Deacon <will.deacon@....com>,
	Christoffer Dall <christoffer.dall@...aro.org>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org, kvmarm@...ts.cs.columbia.edu
Subject: [PATCH v2 05/21] arm64: KVM: VHE: Turn VTCR_EL2 setup into a reusable macro

On a VHE-capable system, there is no point in setting VTCR_EL2
at KVM init time. We can perfectly set it up when the kernel
boots, removing the need for a more complicated configuration.

In order to allow this, turn VTCR_EL2 setup into a macro that
we'll be able to reuse at boot time.

Signed-off-by: Marc Zyngier <marc.zyngier@....com>
---
 arch/arm64/include/asm/kvm_mmu.h | 23 +++++++++++++++++++++++
 arch/arm64/kvm/hyp-init.S        | 18 +-----------------
 2 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 7364339..d3e6d7b 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -56,6 +56,29 @@
 
 #ifdef __ASSEMBLY__
 
+#include <asm/kvm_arm.h>
+
+.macro setup_vtcr tmp1, tmp2
+	mov	\tmp1, #(VTCR_EL2_FLAGS & 0xffff)
+	movk	\tmp1, #(VTCR_EL2_FLAGS >> 16), lsl #16
+	/*
+	 * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in
+	 * VTCR_EL2.
+	 */
+	mrs	\tmp2, id_aa64mmfr0_el1
+	bfi	\tmp1, \tmp2, #16, #3
+	/*
+	 * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS bit in
+	 * VTCR_EL2.
+	 */
+	mrs	\tmp2, ID_AA64MMFR1_EL1
+	ubfx	\tmp2, \tmp2, #5, #1
+	lsl	\tmp2, \tmp2, #VTCR_EL2_VS
+	orr	\tmp1, \tmp1, \tmp2
+
+	msr	vtcr_el2, \tmp1
+	isb
+.endm
 /*
  * Convert a kernel VA into a HYP VA.
  * reg: VA to be converted.
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 3e568dc..4143e2c 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -87,23 +87,7 @@ __do_hyp_init:
 #endif
 	msr	tcr_el2, x4
 
-	ldr	x4, =VTCR_EL2_FLAGS
-	/*
-	 * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in
-	 * VTCR_EL2.
-	 */
-	mrs	x5, ID_AA64MMFR0_EL1
-	bfi	x4, x5, #16, #3
-	/*
-	 * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS bit in
-	 * VTCR_EL2.
-	 */
-	mrs	x5, ID_AA64MMFR1_EL1
-	ubfx	x5, x5, #5, #1
-	lsl	x5, x5, #VTCR_EL2_VS
-	orr	x4, x4, x5
-
-	msr	vtcr_el2, x4
+	setup_vtcr x4, x5
 
 	mrs	x4, mair_el1
 	msr	mair_el2, x4
-- 
2.1.4