1 files changed, 56 insertions, 0 deletions

diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S
new file mode 100644
index 000000000000..f873e75634e1
--- /dev/null
+++ b/arch/s390/kernel/vdso64/gettimeofday.S
@@ -0,0 +1,56 @@
+/*
+ * Userland implementation of gettimeofday() 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_gettimeofday
+        .type  __kernel_gettimeofday,@function
+__kernel_gettimeofday:
+        .cfi_startproc
+        larl    %r5,_vdso_data
+0:      ltgr    %r3,%r3                         /* check if tz is NULL */
+        je      1f
+        mvc     0(8,%r3),__VDSO_TIMEZONE(%r5)
+1:      ltgr    %r2,%r2                         /* check if tv is NULL */
+        je      4f
+        lg      %r4,__VDSO_UPD_COUNT(%r5)       /* load update counter */
+        tmll    %r4,0x0001                      /* pending update ? loop */
+        jnz     0b
+        stck    48(%r15)                        /* Store TOD clock */
+        lg      %r1,48(%r15)
+        sg      %r1,__VDSO_XTIME_STAMP(%r5)     /* TOD - cycle_last */
+        mghi    %r1,1000
+        srlg    %r1,%r1,12                      /* cyc2ns(clock,cycle_delta) */
+        alg     %r1,__VDSO_XTIME_NSEC(%r5)      /*  + xtime.tv_nsec */
+        lg      %r0,__VDSO_XTIME_SEC(%r5)       /* xtime.tv_sec */
+        clg     %r4,__VDSO_UPD_COUNT(%r5)       /* check update counter */
+        jne     0b
+        larl    %r5,5f
+2:      clg     %r1,0(%r5)
+        jl      3f
+        slg     %r1,0(%r5)
+        aghi    %r0,1
+        j       2b
+3:      stg     %r0,0(%r2)                      /* store tv->tv_sec */
+        slgr    %r0,%r0                         /* tv_nsec -> tv_usec */
+        ml      %r0,8(%r5)
+        srlg    %r0,%r0,6
+        stg     %r0,8(%r2)                      /* store tv->tv_usec */
+4:      lghi    %r2,0
+        br      %r14
+5:      .quad   1000000000
+        .long   274877907
+        .cfi_endproc
+        .size   __kernel_gettimeofday,.-__kernel_gettimeofday