From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-4063376-1517257532-2-9001707169402267216 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-api-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1517257531; b=ttzXH/R/2CEKNQkt9eLn+QYKcw6IMkJUtFkYhazNM2+BDc5 Yh2CuWjSpRiewEwS+IYWq/nUc+H1Clz8vmjmptoc/kk//+iTS9GFg5ZQ/ISmpHwA ZHNpx1xizi1DOR9h09gqn931zpAtskfhTuQqlyRIT7PTHbXgomT9xwxETCIQpMPh LZEQ1EFAWI28KAZGCsK4nCZS6nZ0lMXwazz7qFOeV6+Gj/xPUxgvIYLBmmz0GRKt L77SxPMr/w+jTar/f4aYzJUrQ66qeQLNvzjVrc6bT0b4d/aRa8yIZWzYh9O0K2Tr tcpY3z2UeEstpZXyFW2iHjAMYH6z3S2DKJpI3Jg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:sender:list-id; s=arctest; t=1517257531; bh=68PwAi2zQqB7Zt0D9VYF+tHywfhlFXL55o1l0+IS4+M=; b=ZOKKrk4aTCAX Rcb2IaGSiZG+sMZEy/BnzKTBTTaeASu3L+vl6atN0tsLfLdGmgXnWxD8KZeHJqKf eN7tt0a8UNvJ5N243hdvx6pThRQRotgOwAJj2lfKnDRxvQNiURLXsXP5AJRcS0XZ VKUFHR17GbAGhLlKKteVFMv6wcz4iWq/msM/b9axmUs7GRgpu5TSavbQYmcaTdg1 cTP1TSz46V9ROtwVX3IHW4QpKBeCblJrEV2uZ94+kw4iN2ABEjhJLg0r/by/t22u PAniLJckL8C7uY/WIN767oHqPPrXb8aTX0KUMVa9lCmMpUJ/bGUyU3B5Pgm2bu3H ksYq3w3fIA== ARC-Authentication-Results: i=1; mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=efficios.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=efficios.com header.result=pass header_is_org_domain=yes Authentication-Results: mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=efficios.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=efficios.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751993AbeA2UZO (ORCPT ); Mon, 29 Jan 2018 15:25:14 -0500 Received: from mail.efficios.com ([167.114.142.141]:53318 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754660AbeA2UWX (ORCPT ); Mon, 29 Jan 2018 15:22:23 -0500 From: Mathieu Desnoyers 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 Subject: [PATCH for 4.16 v2 06/11] Introduce sync_core_before_usermode Date: Mon, 29 Jan 2018 15:20:15 -0500 Message-Id: <20180129202020.8515-7-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180129202020.8515-1-mathieu.desnoyers@efficios.com> References: <20180129202020.8515-1-mathieu.desnoyers@efficios.com> Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 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 Acked-by: Peter Zijlstra (Intel) CC: Thomas Gleixner 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