From: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>

Add read functions for 64-bit register size to the generic
mmio clocksource, covering both up and down counters.

Signed-off-by: Aleksa Paunovic <aleksa.paunovic@htecgroup.com>
---
 drivers/clocksource/mmio.c  | 14 ++++++++++++++
 include/linux/clocksource.h |  4 ++++
 2 files changed, 18 insertions(+)

diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c
index 9de75153183124cc8997c6ab61d0c01d9b2637bc..6329d8ce2c0911b5c6de34346b5ca8de40b93099 100644
--- a/drivers/clocksource/mmio.c
+++ b/drivers/clocksource/mmio.c
@@ -17,6 +17,20 @@ static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
 	return container_of(c, struct clocksource_mmio, clksrc);
 }
 
+#if defined(readq_relaxed)
+
+u64 clocksource_mmio_readq_up(struct clocksource *c)
+{
+	return (u64)readq_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+u64 clocksource_mmio_readq_down(struct clocksource *c)
+{
+	return ~(u64)readq_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
+}
+
+#endif
+
 u64 clocksource_mmio_readl_up(struct clocksource *c)
 {
 	return (u64)readl_relaxed(to_mmio_clksrc(c)->reg);
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 65b7c41471c390463770c2da13694e58e83b84ea..df8ea45ec60a28e0276020cb95ab5328bec89879 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -276,6 +276,10 @@ static inline void clocksource_arch_init(struct clocksource *cs) { }
 
 extern int timekeeping_notify(struct clocksource *clock);
 
+#if defined(readq_relaxed)
+extern u64 clocksource_mmio_readq_up(struct clocksource *c);
+extern u64 clocksource_mmio_readq_down(struct clocksource *c);
+#endif
 extern u64 clocksource_mmio_readl_up(struct clocksource *);
 extern u64 clocksource_mmio_readl_down(struct clocksource *);
 extern u64 clocksource_mmio_readw_up(struct clocksource *);

-- 
2.43.0