arm64: generic timer: use virtual counter instead of physical at EL0
We want to use the virtual counter at EL0, as the physical counter
may not track the current clocksource for guests running under a
hypervisor.
This patch updates the vdso and generic timer driver to use the virtual
counter. The kernel EL2 entry code is also updated to ensure that the
virtual offset is initialised to zero.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S
index 6681f40..8bf658d 100644
--- a/arch/arm64/kernel/vdso/gettimeofday.S
+++ b/arch/arm64/kernel/vdso/gettimeofday.S
@@ -220,9 +220,9 @@
ldp w11, w12, [vdso_data, #VDSO_CS_MULT]
seqcnt_read w9
- /* Read the physical counter. */
+ /* Read the virtual counter. */
isb
- mrs x15, cntpct_el0
+ mrs x15, cntvct_el0
/* Calculate cycle delta and convert to ns. */
sub x10, x15, x10