From patchwork Wed May 12 15:09:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilias Stamatis X-Patchwork-Id: 12254079 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F153C2B9F2 for ; Wed, 12 May 2021 15:16:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B5DD61979 for ; Wed, 12 May 2021 15:16:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232307AbhELPRL (ORCPT ); Wed, 12 May 2021 11:17:11 -0400 Received: from smtp-fw-80006.amazon.com ([99.78.197.217]:49139 "EHLO smtp-fw-80006.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233423AbhELPNY (ORCPT ); Wed, 12 May 2021 11:13:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1620832336; x=1652368336; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=dd+cfBA8UFfC6dBFQo/XyrQ8fEmJ+IwhldFGtGJFtIU=; b=m8EqzTjxxfM+pZFyDTOxUJKnkFgbKCb3k8KJCFLWynWhIABS1mkQVP4b XnHqRUdMV8+sAVWuvmgcLoKUm9ycYxFOv/nKSoarasVINBpSgAJAU9Upl vINoNlli4mnx6ke2u0Bhan0TWG/UBcKJ+4Q6qZ+CR1LXvW7Jd+dFxhuxk c=; X-IronPort-AV: E=Sophos;i="5.82,293,1613433600"; d="scan'208";a="1007669" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-1a-7d76a15f.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-80006.pdx80.corp.amazon.com with ESMTP; 12 May 2021 15:12:04 +0000 Received: from EX13MTAUEB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-1a-7d76a15f.us-east-1.amazon.com (Postfix) with ESMTPS id AE104A24EF; Wed, 12 May 2021 15:12:00 +0000 (UTC) Received: from EX13D08UEB003.ant.amazon.com (10.43.60.11) by EX13MTAUEB001.ant.amazon.com (10.43.60.129) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 12 May 2021 15:11:45 +0000 Received: from EX13MTAUEB002.ant.amazon.com (10.43.60.12) by EX13D08UEB003.ant.amazon.com (10.43.60.11) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 12 May 2021 15:11:45 +0000 Received: from uae075a0dfd4c51.ant.amazon.com (10.106.82.24) by mail-relay.amazon.com (10.43.60.234) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Wed, 12 May 2021 15:11:43 +0000 From: Ilias Stamatis To: , , CC: , , , , , , , , , Subject: [PATCH v2 01/10] math64.h: Add mul_s64_u64_shr() Date: Wed, 12 May 2021 16:09:36 +0100 Message-ID: <20210512150945.4591-2-ilstam@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210512150945.4591-1-ilstam@amazon.com> References: <20210512150945.4591-1-ilstam@amazon.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This function is needed for the nested TSC scaling code where we need to multiply the signed TSC offset with the unsigned TSC multiplier. Signed-off-by: Ilias Stamatis --- include/linux/math64.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/math64.h b/include/linux/math64.h index 66deb1fdc2ef..2928f03d6d46 100644 --- a/include/linux/math64.h +++ b/include/linux/math64.h @@ -3,6 +3,7 @@ #define _LINUX_MATH64_H #include +#include #include #include @@ -234,6 +235,24 @@ static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift) #endif +#ifndef mul_s64_u64_shr +static inline u64 mul_s64_u64_shr(s64 a, u64 b, unsigned int shift) +{ + u64 ret; + + /* + * Extract the sign before the multiplication and put it back + * afterwards if needed. + */ + ret = mul_u64_u64_shr(abs(a), b, shift); + + if (a < 0) + ret = -((s64) ret); + + return ret; +} +#endif /* mul_s64_u64_shr */ + #ifndef mul_u64_u32_div static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor) {