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-rw-r--r--arch/s390/kernel/vdso64/gettimeofday.S59
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S
new file mode 100644
index 000000000..6ce467076
--- /dev/null
+++ b/arch/s390/kernel/vdso64/gettimeofday.S
@@ -0,0 +1,59 @@
+/*
+ * Userland implementation of gettimeofday() 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_gettimeofday
+ .type __kernel_gettimeofday,@function
+__kernel_gettimeofday:
+ .cfi_startproc
+ aghi %r15,-16
+ larl %r5,_vdso_data
+0: ltgr %r3,%r3 /* check if tz is NULL */
+ je 1f
+ mvc 0(8,%r3),__VDSO_TIMEZONE(%r5)
+1: ltgr %r2,%r2 /* check if tv is NULL */
+ je 4f
+ lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
+ tmll %r4,0x0001 /* pending update ? loop */
+ jnz 0b
+ stcke 0(%r15) /* Store TOD clock */
+ lg %r1,1(%r15)
+ sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
+ msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */
+ alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
+ lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */
+ clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
+ jne 0b
+ lgf %r5,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
+ srlg %r1,%r1,0(%r5) /* >> tk->shift */
+ larl %r5,5f
+2: clg %r1,0(%r5)
+ jl 3f
+ slg %r1,0(%r5)
+ aghi %r0,1
+ j 2b
+3: stg %r0,0(%r2) /* store tv->tv_sec */
+ slgr %r0,%r0 /* tv_nsec -> tv_usec */
+ ml %r0,8(%r5)
+ srlg %r0,%r0,6
+ stg %r0,8(%r2) /* store tv->tv_usec */
+4: lghi %r2,0
+ aghi %r15,16
+ br %r14
+5: .quad 1000000000
+ .long 274877907
+ .cfi_endproc
+ .size __kernel_gettimeofday,.-__kernel_gettimeofday