/* SPDX-License-Identifier: GPL-2.0 */
/*
* Userland implementation of gettimeofday() for 64 bits processes in a
* s390 kernel for use in the vDSO
*
* Copyright IBM Corp. 2008
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
*/
#include <asm/vdso.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/dwarf.h>
#include <asm/ptrace.h>
.text
.align 4
.globl __kernel_gettimeofday
.type __kernel_gettimeofday,@function
__kernel_gettimeofday:
CFI_STARTPROC
aghi %r15,-16
CFI_ADJUST_CFA_OFFSET 16
CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD
larl %r5,_vdso_data
0: ltgr %r3,%r3 /* check if tz is NULL */
je 1f
mvc 0(8,%r3),__VDSO_TIMEZONE(%r5)
1: ltgr %r2,%r2 /* check if tv is NULL */
je 4f
lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
tmll %r4,0x0001 /* pending update ? loop */
jnz 0b
stcke 0(%r15) /* Store TOD clock */
lg %r1,1(%r15)
lg %r0,__VDSO_TS_END(%r5) /* TOD steering end time */
slgr %r0,%r1 /* now - ts_steering_end */
ltgr %r0,%r0 /* past end of steering ? */
jm 6f
srlg %r0,%r0,15 /* 1 per 2^16 */
tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */
jz 7f
lcgr %r0,%r0 /* negative TOD offset */
7: algr %r1,%r0 /* add steering offset */
6: sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */
alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */
clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
jne 0b
lgf %r5,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
srlg %r1,%r1,0(%r5) /* >> tk->shift */
larl %r5,5f
2: clg %r1,0(%r5)
jl 3f
slg %r1,0(%r5)
aghi %r0,1
j 2b
3: stg %r0,0(%r2) /* store tv->tv_sec */
slgr %r0,%r0 /* tv_nsec -> tv_usec */
ml %r0,8(%r5)
srlg %r0,%r0,6
stg %r0,8(%r2) /* store tv->tv_usec */
4: lghi %r2,0
aghi %r15,16
CFI_ADJUST_CFA_OFFSET -16
CFI_RESTORE 15
br %r14
CFI_ENDPROC
5: .quad 1000000000
.long 274877907
.size __kernel_gettimeofday,.-__kernel_gettimeofday
