| Martin Schwidefsky | b020632 | 2008-12-25 13:38:36 +0100 | [diff] [blame] | 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 |
| 23 | 0: ltgr %r3,%r3 /* check if tz is NULL */ |
| 24 | je 1f |
| 25 | mvc 0(8,%r3),__VDSO_TIMEZONE(%r5) |
| 26 | 1: 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 | mghi %r1,1000 |
| 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 |
| 41 | 2: clg %r1,0(%r5) |
| 42 | jl 3f |
| 43 | slg %r1,0(%r5) |
| 44 | aghi %r0,1 |
| 45 | j 2b |
| 46 | 3: 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 */ |
| 51 | 4: lghi %r2,0 |
| 52 | br %r14 |
| 53 | 5: .quad 1000000000 |
| 54 | .long 274877907 |
| 55 | .cfi_endproc |
| 56 | .size __kernel_gettimeofday,.-__kernel_gettimeofday |