[PATCH v3 4/5] arm64: initialise SCTLR2_EL1 at cpu_soft_restart()

[Yeoreum Yun]

SCTLR2_EL1 register is optional starting from ARMv8.8/ARMv9.3,
and becomes mandatory from ARMv8.9/ARMv9.4
and serveral architectural feature are controled by bits in
these registers.

Before, launching new kernel via kexec, initialise SCTLR2_EL1 explicitly.

Signed-off-by: Yeoreum Yun <yeoreum.yun at arm.com>
---
 arch/arm64/kernel/cpu-reset.S | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S
index c87445dde674..123564af345b 100644
--- a/arch/arm64/kernel/cpu-reset.S
+++ b/arch/arm64/kernel/cpu-reset.S
@@ -37,6 +37,12 @@ SYM_TYPED_FUNC_START(cpu_soft_restart)
 	 * regime if HCR_EL2.E2H == 1
 	 */
 	msr	sctlr_el1, x12
+
+alternative_if ARM64_HAS_SCTLR2
+	mov_q	x12, INIT_SCTLR2_EL1
+	msr_s	SYS_SCTLR2_EL1, x12
+alternative_else_nop_endif
+
 	isb
 
 	cbz	x0, 1f				// el2_switch?
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}