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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jul 01, 2020 at 05:18:23PM +0100, Marc Zyngier wrote: > As we are about to disable the vdso for compat tasks in some circumstances, > let's allow a workaround descriptor to provide the vdso_clock_mode that > matches the platform. > > Signed-off-by: Marc Zyngier > --- > arch/arm64/include/asm/arch_timer.h | 3 +++ > drivers/clocksource/arm_arch_timer.c | 3 +++ > 2 files changed, 6 insertions(+) > > diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h > index 7ae54d7d333a..fb8dfcbf9c01 100644 > --- a/arch/arm64/include/asm/arch_timer.h > +++ b/arch/arm64/include/asm/arch_timer.h > @@ -18,6 +18,8 @@ > #include > #include > > +#include > + > #include > > #if IS_ENABLED(CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND) > @@ -58,6 +60,7 @@ struct arch_timer_erratum_workaround { > u64 (*read_cntvct_el0)(void); > int (*set_next_event_phys)(unsigned long, struct clock_event_device *); > int (*set_next_event_virt)(unsigned long, struct clock_event_device *); > + enum vdso_clock_mode vdso_clock_mode; > }; > > DECLARE_PER_CPU(const struct arch_timer_erratum_workaround *, > diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c > index ecf7b7db2d05..f828835c568f 100644 > --- a/drivers/clocksource/arm_arch_timer.c > +++ b/drivers/clocksource/arm_arch_timer.c > @@ -566,6 +566,9 @@ void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa > if (wa->read_cntvct_el0) { > clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_NONE; > vdso_default = VDSO_CLOCKMODE_NONE; > + } else { > + clocksource_counter.vdso_clock_mode = wa->vdso_clock_mode; > + vdso_default = wa->vdso_clock_mode; > } I fear that we're liable to forget to set vdso_clock_mode on new errata that don't need a read_cntvct_el0 hook, and if so we'll happen to set these to 0 (i.e. VDSO_CLOCKMODE_NONE). For now could we instead have a boolan disable_compat_vdso, with this being: | if (wa->read_cntvct_el0) { | clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_NONE; | vdso_default = VDSO_CLOCKMODE_NONE; | } else if (wa->disable_compat_vdso) { | clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT; | vdso_default = wa->vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT; | } Do we need to handle the comination of a workaround seeting NONE and one setting ARCHTIMER_NOCOMPAT? Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel