From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 DB221C2BA19 for ; Mon, 6 Apr 2020 13:41:20 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 498352336E for ; Mon, 6 Apr 2020 13:41:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 498352336E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48wsBk1Qq4zDrCJ for ; Mon, 6 Apr 2020 23:41:18 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48wrPv3x1MzDqf4 for ; Mon, 6 Apr 2020 23:05:55 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix, from userid 1034) id 48wrPp3nXMz9sSJ; Mon, 6 Apr 2020 23:05:47 +1000 (AEST) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 54fc3c681ded9437e4548e2501dc1136b23cfa9a In-Reply-To: <20200331012338.23773-1-aik@ozlabs.ru> To: Alexey Kardashevskiy , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Subject: Re: [PATCH kernel] powerpc/pseries/ddw: Extend upper limit for huge DMA window for persistent memory Message-Id: <48wrPp3nXMz9sSJ@ozlabs.org> Date: Mon, 6 Apr 2020 23:05:47 +1000 (AEST) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Brian J King , Alexey Kardashevskiy , "Aneesh Kumar K . V" , Oliver O'Halloran , David Gibson , Wen Xiong Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, 2020-03-31 at 01:23:38 UTC, Alexey Kardashevskiy wrote: > Unlike normal memory ("memory" compatible type in the FDT), > the persistent memory ("ibm,pmemory" in the FDT) can be mapped anywhere > in the guest physical space and it can be used for DMA. > > In order to maintain 1:1 mapping via the huge DMA window, we need to > know the maximum physical address at the time of the window setup. > So far we've been looking at "memory" nodes but "ibm,pmemory" does not > have fixed addresses and the persistent memory may be mapped afterwards. > > Since the persistent memory is still backed with page structs, > use MAX_PHYSMEM_BITS as the upper limit. > > This effectively disables huge DMA window in LPAR under pHyp if > persistent memory is present but this is the best we can do. > > Signed-off-by: Alexey Kardashevskiy Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/54fc3c681ded9437e4548e2501dc1136b23cfa9a cheers