1 files changed, 74 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/vvar.h b/arch/sparc/include/asm/vvar.h
new file mode 100644
index 000000000000..0289503d1cb0
--- /dev/null
+++ b/arch/sparc/include/asm/vvar.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
+ */
+
+#ifndef _ASM_SPARC_VVAR_DATA_H
+#define _ASM_SPARC_VVAR_DATA_H
+
+#include <asm/clocksource.h>
+#include <linux/seqlock.h>
+#include <linux/time.h>
+#include <linux/types.h>
+
+struct vvar_data {
+	unsigned int seq;
+
+	int vclock_mode;
+	struct { /* extract of a clocksource struct */
+		u64	cycle_last;
+		u64	mask;
+		int	mult;
+		int	shift;
+	} clock;
+	/* open coded 'struct timespec' */
+	u64		wall_time_sec;
+	u64		wall_time_snsec;
+	u64		monotonic_time_snsec;
+	u64		monotonic_time_sec;
+	u64		monotonic_time_coarse_sec;
+	u64		monotonic_time_coarse_nsec;
+	u64		wall_time_coarse_sec;
+	u64		wall_time_coarse_nsec;
+
+	int		tz_minuteswest;
+	int		tz_dsttime;
+};
+
+extern struct vvar_data *vvar_data;
+extern int vdso_fix_stick;
+
+static inline unsigned int vvar_read_begin(const struct vvar_data *s)
+{
+	unsigned int ret;
+
+repeat:
+	ret = READ_ONCE(s->seq);
+	if (unlikely(ret & 1)) {
+		cpu_relax();
+		goto repeat;
+	}
+	smp_rmb(); /* Finish all reads before we return seq */
+	return ret;
+}
+
+static inline int vvar_read_retry(const struct vvar_data *s,
+					unsigned int start)
+{
+	smp_rmb(); /* Finish all reads before checking the value of seq */
+	return unlikely(s->seq != start);
+}
+
+static inline void vvar_write_begin(struct vvar_data *s)
+{
+	++s->seq;
+	smp_wmb(); /* Makes sure that increment of seq is reflected */
+}
+
+static inline void vvar_write_end(struct vvar_data *s)
+{
+	smp_wmb(); /* Makes the value of seq current before we increment */
+	++s->seq;
+}
+
+
+#endif /* _ASM_SPARC_VVAR_DATA_H */