diff options
| author | Mathieu Desnoyers <[email protected]> | 2018-01-29 15:20:15 -0500 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2018-02-05 21:34:50 +0100 |
| commit | e61938a921a46347d7725badc40ec436ebfff977 (patch) | |
| tree | 37e5a38337e0dd53e8bd6a622e101e277f146088 | |
| parent | 92485487ba834f6665ec13dfb2c69e80cd0c7c37 (diff) | |
locking: Introduce sync_core_before_usermode()
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 <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Andrea Parri <[email protected]>
Cc: Andrew Hunter <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Avi Kivity <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Dave Watson <[email protected]>
Cc: David Sehr <[email protected]>
Cc: Greg Hackmann <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Maged Michael <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Russell King <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | include/linux/sync_core.h | 21 | ||||
| -rw-r--r-- | init/Kconfig | 3 |
2 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/sync_core.h b/include/linux/sync_core.h new file mode 100644 index 000000000000..013da4b8b327 --- /dev/null +++ b/include/linux/sync_core.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_SYNC_CORE_H +#define _LINUX_SYNC_CORE_H + +#ifdef CONFIG_ARCH_HAS_SYNC_CORE_BEFORE_USERMODE +#include <asm/sync_core.h> +#else +/* + * This is a dummy sync_core_before_usermode() implementation that can be used + * on all architectures which return to user-space through core serializing + * instructions. + * If your architecture returns to user-space through non-core-serializing + * instructions, you need to write your own functions. + */ +static inline void sync_core_before_usermode(void) +{ +} +#endif + +#endif /* _LINUX_SYNC_CORE_H */ + diff --git a/init/Kconfig b/init/Kconfig index 837adcf075d9..535421facea8 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1918,3 +1918,6 @@ config ASN1 functions to call on what tags. source "kernel/Kconfig.locks" + +config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE + bool |