[S390] introduce vdso on s390
Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for
CLOCK_REALTIME/CLOCK_MONOTONIC.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h
new file mode 100644
index 0000000..a44f4fe
--- /dev/null
+++ b/arch/s390/include/asm/vdso.h
@@ -0,0 +1,39 @@
+#ifndef __S390_VDSO_H__
+#define __S390_VDSO_H__
+
+#ifdef __KERNEL__
+
+/* Default link addresses for the vDSOs */
+#define VDSO32_LBASE 0
+#define VDSO64_LBASE 0
+
+#define VDSO_VERSION_STRING LINUX_2.6.26
+
+#ifndef __ASSEMBLY__
+
+/*
+ * Note about this structure:
+ *
+ * NEVER USE THIS IN USERSPACE CODE DIRECTLY. The layout of this
+ * structure is supposed to be known only to the function in the vdso
+ * itself and may change without notice.
+ */
+
+struct vdso_data {
+ __u64 tb_update_count; /* Timebase atomicity ctr 0x00 */
+ __u64 xtime_tod_stamp; /* TOD clock for xtime 0x08 */
+ __u64 xtime_clock_sec; /* Kernel time 0x10 */
+ __u64 xtime_clock_nsec; /* 0x18 */
+ __u64 wtom_clock_sec; /* Wall to monotonic clock 0x20 */
+ __u64 wtom_clock_nsec; /* 0x28 */
+ __u32 tz_minuteswest; /* Minutes west of Greenwich 0x30 */
+ __u32 tz_dsttime; /* Type of dst correction 0x34 */
+};
+
+extern struct vdso_data *vdso_data;
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __KERNEL__ */
+
+#endif /* __S390_VDSO_H__ */