forked from mirrors/linux
e61938a921
Introduce an architecture function that ensures the current CPU issues a core serializing instruction before returning to usermode. This is needed for the membarrier "sync_core" command. Architectures defining the sync_core_before_usermode() static inline need to select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Andrew Hunter <ahh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Avi Kivity <avi@scylladb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dave Watson <davejwatson@fb.com> Cc: David Sehr <sehr@google.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maged Michael <maged.michael@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/20180129202020.8515-7-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
21 lines
581 B
C
21 lines
581 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_SYNC_CORE_H
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#define _LINUX_SYNC_CORE_H
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#ifdef CONFIG_ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
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#include <asm/sync_core.h>
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#else
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/*
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* This is a dummy sync_core_before_usermode() implementation that can be used
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* on all architectures which return to user-space through core serializing
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* instructions.
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* If your architecture returns to user-space through non-core-serializing
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* instructions, you need to write your own functions.
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*/
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static inline void sync_core_before_usermode(void)
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{
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}
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#endif
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#endif /* _LINUX_SYNC_CORE_H */
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