1/* 2 * Userland implementation of gettimeofday() for 64 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 larl %r5,_vdso_data 230: ltgr %r3,%r3 /* check if tz is NULL */ 24 je 1f 25 mvc 0(8,%r3),__VDSO_TIMEZONE(%r5) 261: ltgr %r2,%r2 /* check if tv is NULL */ 27 je 4f 28 lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ 29 tmll %r4,0x0001 /* pending update ? loop */ 30 jnz 0b 31 stck 48(%r15) /* Store TOD clock */ 32 lg %r1,48(%r15) 33 sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ 34 msgf %r1,__VDSO_NTP_MULT(%r5) /* * NTP adjustment */ 35 srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */ 36 alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime.tv_nsec */ 37 lg %r0,__VDSO_XTIME_SEC(%r5) /* xtime.tv_sec */ 38 clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ 39 jne 0b 40 larl %r5,5f 412: clg %r1,0(%r5) 42 jl 3f 43 slg %r1,0(%r5) 44 aghi %r0,1 45 j 2b 463: stg %r0,0(%r2) /* store tv->tv_sec */ 47 slgr %r0,%r0 /* tv_nsec -> tv_usec */ 48 ml %r0,8(%r5) 49 srlg %r0,%r0,6 50 stg %r0,8(%r2) /* store tv->tv_usec */ 514: lghi %r2,0 52 br %r14 535: .quad 1000000000 54 .long 274877907 55 .cfi_endproc 56 .size __kernel_gettimeofday,.-__kernel_gettimeofday 57