1/*
 2 * Userland implementation of gettimeofday() for 32 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	basr	%r5,0
230:	al	%r5,13f-0b(%r5)			/* get &_vdso_data */
241:	ltr	%r3,%r3				/* check if tz is NULL */
25	je	2f
26	mvc	0(8,%r3),__VDSO_TIMEZONE(%r5)
272:	ltr	%r2,%r2				/* check if tv is NULL */
28	je	10f
29	l	%r4,__VDSO_UPD_COUNT+4(%r5)	/* load update counter */
30	tml	%r4,0x0001			/* pending update ? loop */
31	jnz	1b
32	stck	24(%r15)			/* Store TOD clock */
33	lm	%r0,%r1,24(%r15)
34	s	%r0,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
35	sl	%r1,__VDSO_XTIME_STAMP+4(%r5)
36	brc	3,3f
37	ahi	%r0,-1
383:	ms	%r0,__VDSO_NTP_MULT(%r5)	/* cyc2ns(clock,cycle_delta) */
39	st	%r0,24(%r15)
40	l	%r0,__VDSO_NTP_MULT(%r5)
41	ltr	%r1,%r1
42	mr	%r0,%r0
43	jnm	4f
44	a	%r0,__VDSO_NTP_MULT(%r5)
454:	al	%r0,24(%r15)
46	srdl	%r0,12
47	al	%r0,__VDSO_XTIME_NSEC(%r5)	/*  + xtime */
48	al	%r1,__VDSO_XTIME_NSEC+4(%r5)
49	brc	12,5f
50	ahi	%r0,1
515:	mvc	24(4,%r15),__VDSO_XTIME_SEC+4(%r5)
52	cl	%r4,__VDSO_UPD_COUNT+4(%r5)	/* check update counter */
53	jne	1b
54	l	%r4,24(%r15)			/* get tv_sec from stack */
55	basr	%r5,0
566:	ltr	%r0,%r0
57	jnz	7f
58	cl	%r1,11f-6b(%r5)
59	jl	8f
607:	ahi	%r4,1
61	sl	%r1,11f-6b(%r5)
62	brc	3,6b
63	ahi	%r0,-1
64	j	6b
658:	st	%r4,0(%r2)			/* store tv->tv_sec */
66	ltr	%r1,%r1
67	m	%r0,12f-6b(%r5)
68	jnm	9f
69	al	%r0,12f-6b(%r5)
709:	srl	%r0,6
71	st	%r0,4(%r2)			/* store tv->tv_usec */
7210:	slr	%r2,%r2
73	br	%r14
7411:	.long	1000000000
7512:	.long	274877907
7613:	.long	_vdso_data - 0b
77	.cfi_endproc
78	.size	__kernel_gettimeofday,.-__kernel_gettimeofday