[boot-wrapper 2/3] aarch64: Enable access into SCTLR2_ELx registers from EL2 and below

Anshuman Khandual anshuman.khandual at arm.com
Tue Jul 23 04:06:29 PDT 2024


FEAT_SCTLR2 adds SCTLR2_EL1 and SCTLR2_EL2 system registers But access into
these register from EL2 and below trap to EL3 unless SCR_EL3.D128En is set.

Enable access to SCTLR2_ELx registers when they are implemented.

Signed-off-by: Anshuman Khandual <anshuman.khandual at arm.com>
---
 arch/aarch64/include/asm/cpu.h | 4 +++-
 arch/aarch64/init.c            | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/aarch64/include/asm/cpu.h b/arch/aarch64/include/asm/cpu.h
index 0b8b463..57d66e4 100644
--- a/arch/aarch64/include/asm/cpu.h
+++ b/arch/aarch64/include/asm/cpu.h
@@ -56,6 +56,7 @@
 #define SCR_EL3_HXEn			BIT(38)
 #define SCR_EL3_EnTP2			BIT(41)
 #define SCR_EL3_TCR2EN			BIT(43)
+#define SCR_EL3_SCTLR2En		BIT(44)
 #define SCR_EL3_PIEN			BIT(45)
 #define SCR_EL3_D128En			BIT(47)
 
@@ -81,7 +82,8 @@
 
 #define ID_AA64MMFR1_EL1_HCX		BITS(43, 40)
 
-#define ID_AA64MMFR3_EL1_TCRX		BITS(4, 0)
+#define ID_AA64MMFR3_EL1_TCRX		BITS(3, 0)
+#define ID_AA64MMFR3_EL1_SCTLRX		BITS(7, 4)
 #define ID_AA64MMFR3_EL1_S1PIE		BITS(11, 8)
 #define ID_AA64MMFR3_EL1_S2PIE		BITS(15, 12)
 #define ID_AA64MMFR3_EL1_S1POE		BITS(19, 16)
diff --git a/arch/aarch64/init.c b/arch/aarch64/init.c
index 7d9d0d9..5b21cb8 100644
--- a/arch/aarch64/init.c
+++ b/arch/aarch64/init.c
@@ -92,6 +92,9 @@ void cpu_init_el3(void)
 	if (mrs_field(ID_AA64MMFR3_EL1, D128))
 		scr |= SCR_EL3_D128En;
 
+	if (mrs_field(ID_AA64MMFR3_EL1, SCTLRX))
+		scr |= SCR_EL3_SCTLR2En;
+
 	msr(SCR_EL3, scr);
 
 	msr(CPTR_EL3, cptr);
-- 
2.25.1




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