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

[Marc Zyngier]

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 at 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