/* 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) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License (version 2 only) * as published by the Free Software Foundation. */ #include #include #include .text .align 4 .globl __kernel_gettimeofday .type __kernel_gettimeofday,@function __kernel_gettimeofday: .cfi_startproc aghi %r15,-16 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 br %r14 5: .quad 1000000000 .long 274877907 .cfi_endproc .size __kernel_gettimeofday,.-__kernel_gettimeofday