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arm64: generic timer: use virtual counter instead of physical at EL0

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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>
This commit is contained in:
Will Deacon
2012-11-29 22:48:31 +00:00
committed by Catalin Marinas
parent 45a7905fc4
commit 1f75ff0a3d
4 changed files with 8 additions and 7 deletions
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4
arch/arm64/kernel/vdso/gettimeofday.S
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@@ -220,9 +220,9 @@ ENTRY(__do_get_tspec)
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