1/* 2 * Userland implementation of gettimeofday() for 32 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 basr %r5,0 230: al %r5,13f-0b(%r5) /* get &_vdso_data */ 241: ltr %r3,%r3 /* check if tz is NULL */ 25 je 2f 26 mvc 0(8,%r3),__VDSO_TIMEZONE(%r5) 272: ltr %r2,%r2 /* check if tv is NULL */ 28 je 10f 29 l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ 30 tml %r4,0x0001 /* pending update ? loop */ 31 jnz 1b 32 stck 24(%r15) /* Store TOD clock */ 33 lm %r0,%r1,24(%r15) 34 s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ 35 sl %r1,__VDSO_XTIME_STAMP+4(%r5) 36 brc 3,3f 37 ahi %r0,-1 383: ms %r0,__VDSO_NTP_MULT(%r5) /* cyc2ns(clock,cycle_delta) */ 39 st %r0,24(%r15) 40 l %r0,__VDSO_NTP_MULT(%r5) 41 ltr %r1,%r1 42 mr %r0,%r0 43 jnm 4f 44 a %r0,__VDSO_NTP_MULT(%r5) 454: al %r0,24(%r15) 46 srdl %r0,12 47 al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */ 48 al %r1,__VDSO_XTIME_NSEC+4(%r5) 49 brc 12,5f 50 ahi %r0,1 515: mvc 24(4,%r15),__VDSO_XTIME_SEC+4(%r5) 52 cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ 53 jne 1b 54 l %r4,24(%r15) /* get tv_sec from stack */ 55 basr %r5,0 566: ltr %r0,%r0 57 jnz 7f 58 cl %r1,11f-6b(%r5) 59 jl 8f 607: ahi %r4,1 61 sl %r1,11f-6b(%r5) 62 brc 3,6b 63 ahi %r0,-1 64 j 6b 658: st %r4,0(%r2) /* store tv->tv_sec */ 66 ltr %r1,%r1 67 m %r0,12f-6b(%r5) 68 jnm 9f 69 al %r0,12f-6b(%r5) 709: srl %r0,6 71 st %r0,4(%r2) /* store tv->tv_usec */ 7210: slr %r2,%r2 73 br %r14 7411: .long 1000000000 7512: .long 274877907 7613: .long _vdso_data - 0b 77 .cfi_endproc 78 .size __kernel_gettimeofday,.-__kernel_gettimeofday 79