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-rw-r--r--arch/s390/kernel/vdso64/clock_getres.S39
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso64/clock_getres.S b/arch/s390/kernel/vdso64/clock_getres.S
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index 000000000000..488e31a3c0e7
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+++ b/arch/s390/kernel/vdso64/clock_getres.S
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+/*
+ * Userland implementation of clock_getres() 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_getres
+ .type __kernel_clock_getres,@function
+__kernel_clock_getres:
+ .cfi_startproc
+ cghi %r2,CLOCK_REALTIME
+ je 0f
+ cghi %r2,CLOCK_MONOTONIC
+ jne 2f
+0: ltgr %r3,%r3
+ jz 1f /* res == NULL */
+ larl %r1,3f
+ lg %r0,0(%r1)
+ xc 0(8,%r3),0(%r3) /* set tp->tv_sec to zero */
+ stg %r0,8(%r3) /* store tp->tv_usec */
+1: lghi %r2,0
+ br %r14
+2: lghi %r1,__NR_clock_getres /* fallback to svc */
+ svc 0
+ br %r14
+3: .quad CLOCK_REALTIME_RES
+ .cfi_endproc
+ .size __kernel_clock_getres,.-__kernel_clock_getres