1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Userland implementation of clock_getres() for 64 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_clock_getres
17	.type  __kernel_clock_getres,@function
18__kernel_clock_getres:
19	CFI_STARTPROC
20	larl	%r1,4f
21	cghi	%r2,__CLOCK_REALTIME_COARSE
22	je	0f
23	cghi	%r2,__CLOCK_MONOTONIC_COARSE
24	je	0f
25	larl	%r1,3f
26	cghi	%r2,__CLOCK_REALTIME
27	je	0f
28	cghi	%r2,__CLOCK_MONOTONIC
29	je	0f
30	cghi	%r2,__CLOCK_THREAD_CPUTIME_ID
31	je	0f
32	cghi	%r2,-2		/* Per-thread CPUCLOCK with PID=0, VIRT=1 */
33	jne	2f
34	larl	%r5,_vdso_data
35	icm	%r0,15,__LC_ECTG_OK(%r5)
36	jz	2f
370:	ltgr	%r3,%r3
38	jz	1f				/* res == NULL */
39	lg	%r0,0(%r1)
40	xc	0(8,%r3),0(%r3)			/* set tp->tv_sec to zero */
41	stg	%r0,8(%r3)			/* store tp->tv_usec */
421:	lghi	%r2,0
43	br	%r14
442:	lghi	%r1,__NR_clock_getres		/* fallback to svc */
45	svc	0
46	br	%r14
47	CFI_ENDPROC
483:	.quad	__CLOCK_REALTIME_RES
494:	.quad	__CLOCK_COARSE_RES
50	.size	__kernel_clock_getres,.-__kernel_clock_getres
51