From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by spool.mail.gandi.net (Postfix) with ESMTPS id 2E33C7803DF for ; Thu, 20 Jul 2023 08:28:28 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=df3vBAof6OZmuJYfMCrd+a05fU0O0Nbzgrx6EWWBfJY=; c=relaxed/simple; d=groups.io; h=X-Received:X-Received:X-Received:X-MC-Unique:X-Received:X-Received:X-Received:Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:In-Reply-To:X-Scanned-By:X-Mimecast-Spam-Score:X-Mimecast-Originator:Precedence:List-Unsubscribe:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Reply-To:X-Gm-Message-State:Content-Type:Content-Disposition; s=20140610; t=1689841706; v=1; b=wBgSz1s6TRPrhPujJvhz7JPAoZUG9GDj3GUCr8gf+tNCzmTRqnyiRH0VSAOBQqubLlOa57jQ qzsLlC/PDTJXxrB5xJYtKivLF847yTgO0A3aS5e56dbu7wWb5rTBNDwrcnPzpPpuF5YHSXItJ6X DESYHcipoM+8qfq35VybeDRk= X-Received: by 127.0.0.2 with SMTP id Vrp3YY7687511xrKcCxIk4qz; Thu, 20 Jul 2023 01:28:26 -0700 X-Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mx.groups.io with SMTP id smtpd.web10.8399.1689841706095536106 for ; Thu, 20 Jul 2023 01:28:26 -0700 X-Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-8-NlI8a1blNWmQx8iu5Alnbg-1; Thu, 20 Jul 2023 04:28:19 -0400 X-MC-Unique: NlI8a1blNWmQx8iu5Alnbg-1 X-Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E084E936D28; Thu, 20 Jul 2023 08:28:18 +0000 (UTC) X-Received: from sirius.home.kraxel.org (unknown [10.39.193.89]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A3B25200B41D; Thu, 20 Jul 2023 08:28:18 +0000 (UTC) X-Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id E877918009DC; Thu, 20 Jul 2023 10:28:13 +0200 (CEST) Date: Thu, 20 Jul 2023 10:28:13 +0200 From: "Gerd Hoffmann" To: Ard Biesheuvel Cc: Michael Brown , devel@edk2.groups.io, Jiewen Yao , Jordan Justen Subject: Re: [edk2-devel] [PATCH 1/1] OvmfPkg/IoMmuDxe: add locking to IoMmuAllocateBounceBuffer Message-ID: <57y2vtkzqkqjfoft2vn7gem527frwh3i4ymk7piaztyxlfz4fz@eqeuogfkl5vf> References: <20230719113317.276124-1-kraxel@redhat.com> <010201896ee54d34-2b5c712c-d799-49b0-a2eb-f0838988b313-000000@eu-west-1.amazonses.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Precedence: Bulk List-Unsubscribe: List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Reply-To: devel@edk2.groups.io,kraxel@redhat.com X-Gm-Message-State: UB7CAEa3kvOwptDsVtBRHK98x7686176AA= Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20140610 header.b=wBgSz1s6; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=redhat.com (policy=none); spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce@groups.io > > > mReservedMemBitmap &= (UINT32)(~MapInfo->ReservedMemBitmap); > > > > I'd expect modern compilers optimize that to a single instruction, > > You mean something along the lines of > > andl %reg, mReservedMemBitmap(%rip) > > right? Yes. > > but > > yes, it's not guaranteed to happen, the compiler can choose to generate > > a series of load + and + store instructions instead. > > That is sadly all we have on ARM, unless you use LSE atomics, which > are optional in the architecture so we never use those in EDK2. ARM means v7 only or both v7+v8? take care, Gerd -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#107089): https://edk2.groups.io/g/devel/message/107089 Mute This Topic: https://groups.io/mt/100233359/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io] -=-=-=-=-=-=-=-=-=-=-=-