[PATCH v3 1/5] arm64: make SCTLR2_EL1 accessible

[Yeoreum Yun]

When the kernel runs at EL1, and yet is booted at EL2,
HCRX_EL2.SCTLR2En must be set to avoid trapping SCTLR2_EL1 accesses
from EL1 to EL2.

Ensure this bit is set at the point of initialising EL2.

Signed-off-by: Yeoreum Yun <yeoreum.yun at arm.com>
Reviewed-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/include/asm/el2_setup.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index 46033027510c..d755b4d46d77 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -57,9 +57,15 @@
         /* Enable GCS if supported */
 	mrs_s	x1, SYS_ID_AA64PFR1_EL1
 	ubfx	x1, x1, #ID_AA64PFR1_EL1_GCS_SHIFT, #4
-	cbz	x1, .Lset_hcrx_\@
+	cbz	x1, .Lskip_hcrx_GCSEn_\@
 	orr	x0, x0, #HCRX_EL2_GCSEn
 
+.Lskip_hcrx_GCSEn_\@:
+	mrs_s	x1, SYS_ID_AA64MMFR3_EL1
+	ubfx	x1, x1, #ID_AA64MMFR3_EL1_SCTLRX_SHIFT, #4
+	cbz	x1, .Lset_hcrx_\@
+	orr	x0, x0, HCRX_EL2_SCTLR2En
+
 .Lset_hcrx_\@:
 	msr_s	SYS_HCRX_EL2, x0
 .Lskip_hcrx_\@:
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}