/*
* 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
