diff options
| author | Will Deacon <will.deacon@arm.com> | 2012-11-29 22:48:31 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2012-12-05 11:20:04 +0000 |
| commit | 1f75ff0a3d63606c1345e316e88a903fd43ca8be (patch) | |
| tree | d326cb2f58040c910390e80f5a5287b0074a0276 /arch/arm64/kernel | |
| parent | 45a7905fc48f6079932e77d64237cf7f008db5f4 (diff) | |
| download | linux-1f75ff0a3d63606c1345e316e88a903fd43ca8be.tar.gz | |
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>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/head.S | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/gettimeofday.S | 4 |
2 files changed, 3 insertions, 2 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index a2f02b63eae9..90dec55b17a2 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -158,6 +158,7 @@ ENTRY(el2_setup) mrs x0, cnthctl_el2 orr x0, x0, #3 // Enable EL1 physical timers msr cnthctl_el2, x0 + msr cntvoff_el2, xzr // Clear virtual offset /* Populate ID registers. */ mrs x0, midr_el1 diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index 6681f4032260..8bf658d974f9 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -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 |