1 files changed, 39 insertions, 0 deletions

diff --git a/arch/s390/kernel/vdso64/clock_getres.S b/arch/s390/kernel/vdso64/clock_getres.S
new file mode 100644
index 000000000000..488e31a3c0e7
--- /dev/null
+++ b/arch/s390/kernel/vdso64/clock_getres.S
@@ -0,0 +1,39 @@
+/*
+ * Userland implementation of clock_getres() for 64 bits processes in a
+ * s390 kernel for use in the vDSO
+ *
+ *  Copyright IBM Corp. 2008
+ *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ */
+#include <asm/vdso.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+
+        .text
+        .align 4
+        .globl __kernel_clock_getres
+        .type  __kernel_clock_getres,@function
+__kernel_clock_getres:
+        .cfi_startproc
+        cghi    %r2,CLOCK_REALTIME
+        je      0f
+        cghi    %r2,CLOCK_MONOTONIC
+        jne     2f
+0:      ltgr    %r3,%r3
+        jz      1f                              /* res == NULL */
+        larl    %r1,3f
+        lg      %r0,0(%r1)
+        xc      0(8,%r3),0(%r3)                 /* set tp->tv_sec to zero */
+        stg     %r0,8(%r3)                      /* store tp->tv_usec */
+1:      lghi    %r2,0
+        br      %r14
+2:      lghi    %r1,__NR_clock_getres           /* fallback to svc */
+        svc     0
+        br      %r14
+3:      .quad   CLOCK_REALTIME_RES
+        .cfi_endproc
+        .size   __kernel_clock_getres,.-__kernel_clock_getres