1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Userland implementation of gettimeofday() for 32 bits processes in a
4 * s390 kernel for use in the vDSO
5 *
6 *  Copyright IBM Corp. 2008
7 *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
8 */
9#include <asm/vdso.h>
10#include <asm/asm-offsets.h>
11#include <asm/unistd.h>
12#include <asm/dwarf.h>
13
14	.text
15	.align 4
16	.globl __kernel_gettimeofday
17	.type  __kernel_gettimeofday,@function
18__kernel_gettimeofday:
19	CFI_STARTPROC
20	ahi	%r15,-16
21	CFI_ADJUST_CFA_OFFSET 16
22	CFI_VAL_OFFSET 15, -160
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,__VDSO_TS_END(%r5)	/* TOD steering end time */
35	s	%r0,1(%r15)
36	sl	%r1,5(%r15)
37	brc	3,14f
38	ahi	%r0,-1
3914:	ltr	%r0,%r0				/* past end of steering? */
40	jm	16f
41	srdl	%r0,15				/* 1 per 2^16 */
42	tm	__VDSO_TS_DIR+3(%r5),0x01	/* steering direction? */
43	jz	15f
44	lcr	%r0,%r0				/* negative TOD offset */
45	lcr	%r1,%r1
46	je	15f
47	ahi	%r0,-1
4815:	a	%r0,1(%r15)			/* add TOD timestamp */
49	al	%r1,5(%r15)
50	brc	12,17f
51	ahi	%r0,1
52	j	17f
5316:	lm	%r0,%r1,1(%r15)			/* load TOD timestamp */
5417:	s	%r0,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
55	sl	%r1,__VDSO_XTIME_STAMP+4(%r5)
56	brc	3,3f
57	ahi	%r0,-1
583:	ms	%r0,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
59	st	%r0,0(%r15)
60	l	%r0,__VDSO_TK_MULT(%r5)
61	ltr	%r1,%r1
62	mr	%r0,%r0
63	jnm	4f
64	a	%r0,__VDSO_TK_MULT(%r5)
654:	al	%r0,0(%r15)
66	al	%r0,__VDSO_XTIME_NSEC(%r5)	/*  + xtime */
67	al	%r1,__VDSO_XTIME_NSEC+4(%r5)
68	brc	12,5f
69	ahi	%r0,1
705:	mvc	0(4,%r15),__VDSO_XTIME_SEC+4(%r5)
71	cl	%r4,__VDSO_UPD_COUNT+4(%r5)	/* check update counter */
72	jne	1b
73	l	%r4,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
74	srdl	%r0,0(%r4)			/*  >> tk->shift */
75	l	%r4,0(%r15)			/* get tv_sec from stack */
76	basr	%r5,0
776:	ltr	%r0,%r0
78	jnz	7f
79	cl	%r1,11f-6b(%r5)
80	jl	8f
817:	ahi	%r4,1
82	sl	%r1,11f-6b(%r5)
83	brc	3,6b
84	ahi	%r0,-1
85	j	6b
868:	st	%r4,0(%r2)			/* store tv->tv_sec */
87	ltr	%r1,%r1
88	m	%r0,12f-6b(%r5)
89	jnm	9f
90	al	%r0,12f-6b(%r5)
919:	srl	%r0,6
92	st	%r0,4(%r2)			/* store tv->tv_usec */
9310:	slr	%r2,%r2
94	ahi	%r15,16
95	CFI_ADJUST_CFA_OFFSET -16
96	CFI_RESTORE 15
97	br	%r14
98	CFI_ENDPROC
9911:	.long	1000000000
10012:	.long	274877907
10113:	.long	_vdso_data - 0b
102	.size	__kernel_gettimeofday,.-__kernel_gettimeofday
103