[PATCH 05/17] arm64: Allow EL1 physical timer access when running VHE

Marc Zyngier maz at kernel.org
Thu Oct 20 02:07:15 PDT 2022


To initialise the timer access from EL2 when HCR_EL2.E2H is set,
we must make use the CNTHCTL_EL2 formap used is appropriate.

This amounts to shifting the timer/counter enable bits by 10
to the left.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/include/asm/el2_setup.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index 668569adf4d3..fa1045f709bb 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -34,6 +34,11 @@
  */
 .macro __init_el2_timers
 	mov	x0, #3				// Enable EL1 physical timers
+	mrs	x1, hcr_el2
+	and	x1, x1, #HCR_E2H
+	cbz	x1, .LnVHE_\@
+	lsl	x0, x0, #10
+.LnVHE_\@:
 	msr	cnthctl_el2, x0
 	msr	cntvoff_el2, xzr		// Clear virtual offset
 .endm
-- 
2.34.1




More information about the linux-arm-kernel mailing list