| /* |
| * Userland implementation of clock_gettime() 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 <asm/vdso.h> |
| #include <asm/asm-offsets.h> |
| #include <asm/unistd.h> |
| |
| .text |
| .align 4 |
| .globl __kernel_clock_gettime |
| .type __kernel_clock_gettime,@function |
| __kernel_clock_gettime: |
| .cfi_startproc |
| larl %r5,_vdso_data |
| cghi %r2,CLOCK_REALTIME |
| je 4f |
| cghi %r2,CLOCK_MONOTONIC |
| jne 9f |
| |
| /* CLOCK_MONOTONIC */ |
| ltgr %r3,%r3 |
| jz 3f /* tp == NULL */ |
| 0: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ |
| tmll %r4,0x0001 /* pending update ? loop */ |
| jnz 0b |
| stck 48(%r15) /* Store TOD clock */ |
| lg %r1,48(%r15) |
| sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ |
| mghi %r1,1000 |
| srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */ |
| alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */ |
| lg %r0,__VDSO_XTIME_SEC(%r5) |
| alg %r1,__VDSO_WTOM_NSEC(%r5) /* + wall_to_monotonic */ |
| alg %r0,__VDSO_WTOM_SEC(%r5) |
| clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ |
| jne 0b |
| larl %r5,10f |
| 1: clg %r1,0(%r5) |
| jl 2f |
| slg %r1,0(%r5) |
| aghi %r0,1 |
| j 1b |
| 2: stg %r0,0(%r3) /* store tp->tv_sec */ |
| stg %r1,8(%r3) /* store tp->tv_nsec */ |
| 3: lghi %r2,0 |
| br %r14 |
| |
| /* CLOCK_REALTIME */ |
| 4: ltr %r3,%r3 /* tp == NULL */ |
| jz 8f |
| 5: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ |
| tmll %r4,0x0001 /* pending update ? loop */ |
| jnz 5b |
| stck 48(%r15) /* Store TOD clock */ |
| lg %r1,48(%r15) |
| sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ |
| mghi %r1,1000 |
| srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */ |
| alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */ |
| lg %r0,__VDSO_XTIME_SEC(%r5) |
| clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ |
| jne 5b |
| larl %r5,10f |
| 6: clg %r1,0(%r5) |
| jl 7f |
| slg %r1,0(%r5) |
| aghi %r0,1 |
| j 6b |
| 7: stg %r0,0(%r3) /* store tp->tv_sec */ |
| stg %r1,8(%r3) /* store tp->tv_nsec */ |
| 8: lghi %r2,0 |
| br %r14 |
| |
| /* Fallback to system call */ |
| 9: lghi %r1,__NR_clock_gettime |
| svc 0 |
| br %r14 |
| |
| 10: .quad 1000000000 |
| .cfi_endproc |
| .size __kernel_clock_gettime,.-__kernel_clock_gettime |