In an effort to unify the common code for managing the vdso library in
between all the architectures that support it, this patch tries to
provide a common format for the vdso datapage.
As a result of this, this patch generalized the data structures in vgtod.h
from x86 private includes to general includes (include/vdso).
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
---
include/vdso/datapage.h | 74 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 74 insertions(+)
create mode 100644 include/vdso/datapage.h
diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h
new file mode 100644
index 000000000000..da346ad02b03
--- /dev/null
+++ b/include/vdso/datapage.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __VDSO_DATAPAGE_H
+#define __VDSO_DATAPAGE_H
+
+#ifdef __KERNEL__
+
+#ifndef __ASSEMBLY__
+
+#include <linux/bits.h>
+#include <linux/types.h>
+#include <linux/time.h>
+
+#define VDSO_BASES (CLOCK_TAI + 1)
+#define VDSO_HRES (BIT(CLOCK_REALTIME) | \
+ BIT(CLOCK_MONOTONIC) | \
+ BIT(CLOCK_MONOTONIC_RAW) | \
+ BIT(CLOCK_BOOTTIME) | \
+ BIT(CLOCK_TAI))
+#define VDSO_COARSE (BIT(CLOCK_REALTIME_COARSE) | \
+ BIT(CLOCK_MONOTONIC_COARSE))
+
+/*
+ * There is one vdso_timestamp object in vvar for each vDSO-accelerated
+ * clock_id. For high-resolution clocks, this encodes the time
+ * corresponding to vdso_data.cycle_last. For coarse clocks this encodes
+ * the actual time.
+ *
+ * To be noticed that for highres clocks nsec is left-shifted by
+ * vdso_data.cs[x].shift.
+ */
+struct vdso_timestamp {
+ u64 sec;
+ u64 nsec;
+};
+
+#define CLOCKSOURCE_RAW 0
+#define CLOCKSOURCE_MONO 1
+#define CLOCKSOURCE_BASES (CLOCKSOURCE_MONO + 1)
+
+/*
+ * There is one vdso_clocksource object in vvar for each vDSO clocksource
+ * (mono, raw). This struct is designed to keep vdso_data "cache-line friendly"
+ * and optimal in terms of access pattern.
+ *
+ * Note that mask and shift are the same for mono and raw.
+ */
+struct vdso_clocksource {
+ u64 mask; /* Clocksource mask */
+ u32 mult; /* Clocksource multiplier */
+ u32 shift; /* Clocksource shift */
+};
+
+/*
+ * vdso_data will be accessed by 32 and 64 bit code at the same time
+ * so we should be careful before modifying this structure.
+ */
+struct vdso_data {
+ u32 seq; /* Timebase sequence counter */
+
+ s32 clock_mode;
+ u64 cycle_last; /* Timebase at clocksource init */
+
+ struct vdso_clocksource cs[CLOCKSOURCE_BASES];
+ struct vdso_timestamp basetime[VDSO_BASES];
+
+ s32 tz_minuteswest; /* Timezone definitions */
+ s32 tz_dsttime;
+};
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __KERNEL__ */
+
+#endif /* __VDSO_DATAPAGE_H */
--
2.20.1
