[PATCH 2/3] arm64: arch_timer: Allow an workaround descriptor to provide vdso_clock_mode

Marc Zyngier
2020-07-01T16:18:43Z

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 <maz@kernel.org>
---
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 <linux/smp.h>
#include <linux/types.h>

+#include <vdso/clocksource.h>
+
#include <clocksource/arm_arch_timer.h>

#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;
}
}

--
2.27.0