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	ahi	%r15,-16
23	basr	%r5,0
240:	al	%r5,13f-0b(%r5)			/* get &_vdso_data */
251:	ltr	%r3,%r3				/* check if tz is NULL */
26	je	2f
27	mvc	0(8,%r3),__VDSO_TIMEZONE(%r5)
282:	ltr	%r2,%r2				/* check if tv is NULL */
29	je	10f
30	l	%r4,__VDSO_UPD_COUNT+4(%r5)	/* load update counter */
31	tml	%r4,0x0001			/* pending update ? loop */
32	jnz	1b
33	stcke	0(%r15)				/* Store TOD clock */
34	lm	%r0,%r1,1(%r15)
35	s	%r0,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
36	sl	%r1,__VDSO_XTIME_STAMP+4(%r5)
37	brc	3,3f
38	ahi	%r0,-1
393:	ms	%r0,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
40	st	%r0,0(%r15)
41	l	%r0,__VDSO_TK_MULT(%r5)
42	ltr	%r1,%r1
43	mr	%r0,%r0
44	jnm	4f
45	a	%r0,__VDSO_TK_MULT(%r5)
464:	al	%r0,0(%r15)
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	0(4,%r15),__VDSO_XTIME_SEC+4(%r5)
52	cl	%r4,__VDSO_UPD_COUNT+4(%r5)	/* check update counter */
53	jne	1b
54	l	%r4,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
55	srdl	%r0,0(%r4)			/*  >> tk->shift */
56	l	%r4,0(%r15)			/* get tv_sec from stack */
57	basr	%r5,0
586:	ltr	%r0,%r0
59	jnz	7f
60	cl	%r1,11f-6b(%r5)
61	jl	8f
627:	ahi	%r4,1
63	sl	%r1,11f-6b(%r5)
64	brc	3,6b
65	ahi	%r0,-1
66	j	6b
678:	st	%r4,0(%r2)			/* store tv->tv_sec */
68	ltr	%r1,%r1
69	m	%r0,12f-6b(%r5)
70	jnm	9f
71	al	%r0,12f-6b(%r5)
729:	srl	%r0,6
73	st	%r0,4(%r2)			/* store tv->tv_usec */
7410:	slr	%r2,%r2
75	ahi	%r15,16
76	br	%r14
7711:	.long	1000000000
7812:	.long	274877907
7913:	.long	_vdso_data - 0b
80	.cfi_endproc
81	.size	__kernel_gettimeofday,.-__kernel_gettimeofday