1/*
2 * Userland implementation of gettimeofday() for 64 bits processes in a
3 * s390 kernel for use in the vDSO
4 *
5 *  Copyright IBM Corp. 2008
6 *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License (version 2 only)
10 * as published by the Free Software Foundation.
11 */
12#include <asm/vdso.h>
13#include <asm/asm-offsets.h>
14#include <asm/unistd.h>
15
16	.text
17	.align 4
18	.globl __kernel_gettimeofday
19	.type  __kernel_gettimeofday,@function
20__kernel_gettimeofday:
21	.cfi_startproc
22	aghi	%r15,-16
23	larl	%r5,_vdso_data
240:	ltgr	%r3,%r3				/* check if tz is NULL */
25	je	1f
26	mvc	0(8,%r3),__VDSO_TIMEZONE(%r5)
271:	ltgr	%r2,%r2				/* check if tv is NULL */
28	je	4f
29	lg	%r4,__VDSO_UPD_COUNT(%r5)	/* load update counter */
30	tmll	%r4,0x0001			/* pending update ? loop */
31	jnz	0b
32	stcke	0(%r15)				/* Store TOD clock */
33	lg	%r1,1(%r15)
34	sg	%r1,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
35	msgf	%r1,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
36	alg	%r1,__VDSO_XTIME_NSEC(%r5)	/*  + tk->xtime_nsec */
37	lg	%r0,__VDSO_XTIME_SEC(%r5)	/* tk->xtime_sec */
38	clg	%r4,__VDSO_UPD_COUNT(%r5)	/* check update counter */
39	jne	0b
40	lgf	%r5,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
41	srlg	%r1,%r1,0(%r5)			/*  >> tk->shift */
42	larl	%r5,5f
432:	clg	%r1,0(%r5)
44	jl	3f
45	slg	%r1,0(%r5)
46	aghi	%r0,1
47	j	2b
483:	stg	%r0,0(%r2)			/* store tv->tv_sec */
49	slgr	%r0,%r0				/* tv_nsec -> tv_usec */
50	ml	%r0,8(%r5)
51	srlg	%r0,%r0,6
52	stg	%r0,8(%r2)			/* store tv->tv_usec */
534:	lghi	%r2,0
54	aghi	%r15,16
55	br	%r14
565:	.quad	1000000000
57	.long	274877907
58	.cfi_endproc
59	.size	__kernel_gettimeofday,.-__kernel_gettimeofday
60