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linux/arch/s390/kernel/vdso64/clock_getres.S

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[S390] introduce vdso on s390 Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for CLOCK_REALTIME/CLOCK_MONOTONIC. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 15:38:36 +03:00
/*
* 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
s390/vdso: add vdso support for coarse clocks Add CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE optimization to the 64-bit and 31-bit vdso. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-08-29 14:31:45 +04:00
larl %r1,4f
cghi %r2,__CLOCK_REALTIME_COARSE
je 0f
cghi %r2,__CLOCK_MONOTONIC_COARSE
je 0f
larl %r1,3f
[S390] vdso: get rid of redefinition warnings The CLOCK_* defines in asm-offsets.c are only used for the vdso code however in the meantime they cause other trouble. Just rename them to get permanently rid of this: In file included from /home2/heicarst/linux-2.6/arch/s390/include/asm/asm-offsets.h:1:0, from arch/s390/mm/fault.c:33: include/generated/asm-offsets.h:53:0: warning: "CLOCK_REALTIME" redefined include/linux/time.h:286:0: note: this is the location of the previous definition include/generated/asm-offsets.h:54:0: warning: "CLOCK_MONOTONIC" redefined include/linux/time.h:287:0: note: this is the location of the previous definition Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29 18:50:41 +04:00
cghi %r2,__CLOCK_REALTIME
[S390] introduce vdso on s390 Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for CLOCK_REALTIME/CLOCK_MONOTONIC. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 15:38:36 +03:00
je 0f
[S390] vdso: get rid of redefinition warnings The CLOCK_* defines in asm-offsets.c are only used for the vdso code however in the meantime they cause other trouble. Just rename them to get permanently rid of this: In file included from /home2/heicarst/linux-2.6/arch/s390/include/asm/asm-offsets.h:1:0, from arch/s390/mm/fault.c:33: include/generated/asm-offsets.h:53:0: warning: "CLOCK_REALTIME" redefined include/linux/time.h:286:0: note: this is the location of the previous definition include/generated/asm-offsets.h:54:0: warning: "CLOCK_MONOTONIC" redefined include/linux/time.h:287:0: note: this is the location of the previous definition Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29 18:50:41 +04:00
cghi %r2,__CLOCK_MONOTONIC
[PATCH] fast vdso implementation for CLOCK_THREAD_CPUTIME_ID The extract cpu time instruction (ectg) instruction allows the user process to get the current thread cputime without calling into the kernel. The code that uses the instruction needs to switch to the access registers mode to get access to the per-cpu info page that contains the two base values that are needed to calculate the current cputime from the CPU timer with the ectg instruction. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 17:11:42 +03:00
je 0f
s390/vdso: ectg gettime support for CLOCK_THREAD_CPUTIME_ID The code to use the ECTG instruction to calculate the cputime for the current thread is currently used only for the per-thread CPU-clock with the clockid -2 (PID=0, VIRT=1). Use the same code for the clockid CLOCK_THREAD_CPUTIME_ID to speed up the more common clockid as well. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-12-02 17:54:56 +04:00
cghi %r2,__CLOCK_THREAD_CPUTIME_ID
je 0f
cghi %r2,-2 /* Per-thread CPUCLOCK with PID=0, VIRT=1 */
[S390] introduce vdso on s390 Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for CLOCK_REALTIME/CLOCK_MONOTONIC. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 15:38:36 +03:00
jne 2f
[PATCH] fast vdso implementation for CLOCK_THREAD_CPUTIME_ID The extract cpu time instruction (ectg) instruction allows the user process to get the current thread cputime without calling into the kernel. The code that uses the instruction needs to switch to the access registers mode to get access to the per-cpu info page that contains the two base values that are needed to calculate the current cputime from the CPU timer with the ectg instruction. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31 17:11:42 +03:00
larl %r5,_vdso_data
icm %r0,15,__LC_ECTG_OK(%r5)
jz 2f
[S390] introduce vdso on s390 Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for CLOCK_REALTIME/CLOCK_MONOTONIC. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 15:38:36 +03:00
0: ltgr %r3,%r3
jz 1f /* res == NULL */
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
[S390] vdso: get rid of redefinition warnings The CLOCK_* defines in asm-offsets.c are only used for the vdso code however in the meantime they cause other trouble. Just rename them to get permanently rid of this: In file included from /home2/heicarst/linux-2.6/arch/s390/include/asm/asm-offsets.h:1:0, from arch/s390/mm/fault.c:33: include/generated/asm-offsets.h:53:0: warning: "CLOCK_REALTIME" redefined include/linux/time.h:286:0: note: this is the location of the previous definition include/generated/asm-offsets.h:54:0: warning: "CLOCK_MONOTONIC" redefined include/linux/time.h:287:0: note: this is the location of the previous definition Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29 18:50:41 +04:00
3: .quad __CLOCK_REALTIME_RES
s390/vdso: add vdso support for coarse clocks Add CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE optimization to the 64-bit and 31-bit vdso. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-08-29 14:31:45 +04:00
4: .quad __CLOCK_COARSE_RES
[S390] introduce vdso on s390 Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for CLOCK_REALTIME/CLOCK_MONOTONIC. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-25 15:38:36 +03:00
.cfi_endproc
.size __kernel_clock_getres,.-__kernel_clock_getres
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