From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Subject: [PATCH 06/11] Introduce sync_core_before_usermode (v2) Date: Tue, 23 Jan 2018 10:57:28 -0500 Message-ID: <20180123155733.3404-7-mathieu.desnoyers@efficios.com> References: <20180123155733.3404-1-mathieu.desnoyers@efficios.com> Return-path: In-Reply-To: <20180123155733.3404-1-mathieu.desnoyers@efficios.com> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar , Peter Zijlstra , Thomas Gleixner Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Andy Lutomirski , "Paul E . McKenney" , Boqun Feng , Andrew Hunter , Maged Michael , Avi Kivity , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Dave Watson , "H . Peter Anvin" , Andrea Parri , Russell King , Greg Hackmann , Will Deacon , David Sehr , Linus Torvalds , x86@kernel.org, Mathieu Desnoyers List-Id: linux-arch.vger.kernel.org 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 CC: Thomas Gleixner CC: Peter Zijlstra CC: Andy Lutomirski CC: Paul E. McKenney CC: Boqun Feng CC: Andrew Hunter CC: Maged Michael CC: Avi Kivity CC: Benjamin Herrenschmidt CC: Paul Mackerras CC: Michael Ellerman CC: Dave Watson CC: Ingo Molnar CC: "H. Peter Anvin" CC: Andrea Parri CC: Russell King CC: Greg Hackmann CC: Will Deacon CC: David Sehr CC: Linus Torvalds CC: Arnd Bergmann CC: x86@kernel.org CC: linux-arch@vger.kernel.org --- Changes since v1: - Introduce include/linux/sync_core.h --- include/linux/sync_core.h | 21 +++++++++++++++++++++ init/Kconfig | 3 +++ 2 files changed, 24 insertions(+) create mode 100644 include/linux/sync_core.h 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 +#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 2d118b6adee2..30208da2221f 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 -- 2.11.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.efficios.com ([167.114.142.141]:34854 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752392AbeAWP6M (ORCPT ); Tue, 23 Jan 2018 10:58:12 -0500 From: Mathieu Desnoyers Subject: [PATCH 06/11] Introduce sync_core_before_usermode (v2) Date: Tue, 23 Jan 2018 10:57:28 -0500 Message-ID: <20180123155733.3404-7-mathieu.desnoyers@efficios.com> In-Reply-To: <20180123155733.3404-1-mathieu.desnoyers@efficios.com> References: <20180123155733.3404-1-mathieu.desnoyers@efficios.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Ingo Molnar , Peter Zijlstra , Thomas Gleixner Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Andy Lutomirski , "Paul E . McKenney" , Boqun Feng , Andrew Hunter , Maged Michael , Avi Kivity , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Dave Watson , "H . Peter Anvin" , Andrea Parri , Russell King , Greg Hackmann , Will Deacon , David Sehr , Linus Torvalds , x86@kernel.org, Mathieu Desnoyers , Arnd Bergmann , linux-arch@vger.kernel.org Message-ID: <20180123155728.SBjC39NWOJdk7KDjHKxCPZ9eYVkQcOCapmHoXGWOC-0@z> 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 CC: Thomas Gleixner CC: Peter Zijlstra CC: Andy Lutomirski CC: Paul E. McKenney CC: Boqun Feng CC: Andrew Hunter CC: Maged Michael CC: Avi Kivity CC: Benjamin Herrenschmidt CC: Paul Mackerras CC: Michael Ellerman CC: Dave Watson CC: Ingo Molnar CC: "H. Peter Anvin" CC: Andrea Parri CC: Russell King CC: Greg Hackmann CC: Will Deacon CC: David Sehr CC: Linus Torvalds CC: Arnd Bergmann CC: x86@kernel.org CC: linux-arch@vger.kernel.org --- Changes since v1: - Introduce include/linux/sync_core.h --- include/linux/sync_core.h | 21 +++++++++++++++++++++ init/Kconfig | 3 +++ 2 files changed, 24 insertions(+) create mode 100644 include/linux/sync_core.h 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 +#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 2d118b6adee2..30208da2221f 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 -- 2.11.0