Messages in this thread Patch in this message | | | From | Marc Zyngier <> | Subject | [PATCH 15/16] clocksource/arm_arch_timer: Add helper to disable VDSO fastpath | Date | Fri, 21 Jul 2017 18:15:41 +0100 |
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As we are going to add more paths where we have to disable the counter access in the VDSO, let's add a helper that does exactly that.
Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- drivers/clocksource/arm_arch_timer.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index aae87c4c546e..4f4633157978 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -188,6 +188,22 @@ struct ate_acpi_oem_info { u32 oem_revision; }; +static void __maybe_unused disable_vdso(void) +{ + /* + * Don't use the vdso fastpath if errata require using the + * out-of-line counter accessor and/or trap its access. We may + * change our mind pretty late in the game (with a per-CPU + * erratum, for example), so change both the default value and + * the vdso itself. + */ + if (vdso_default) { + pr_info("Disabling VDSO direct access\n"); + clocksource_counter.archdata.vdso_direct = false; + vdso_default = false; + } +} + #ifdef CONFIG_FSL_ERRATUM_A008585 /* * The number of retries is an arbitrary value well beyond the highest number @@ -457,16 +473,8 @@ void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa static_branch_enable(&arch_timer_read_ool_enabled); - /* - * Don't use the vdso fastpath if errata require using the - * out-of-line counter accessor. We may change our mind pretty - * late in the game (with a per-CPU erratum, for example), so - * change both the default value and the vdso itself. - */ - if (wa->read_cntvct_el0) { - clocksource_counter.archdata.vdso_direct = false; - vdso_default = false; - } + if (wa->read_cntvct_el0) + disable_vdso(); } static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type type, -- 2.11.0
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