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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B8B9C433EF for ; Mon, 8 Nov 2021 04:05:05 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 245B760EE0 for ; Mon, 8 Nov 2021 04:05:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 245B760EE0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ozlabs.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Hncvf68msz3064 for ; Mon, 8 Nov 2021 15:05:02 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.ru (client-ip=107.174.27.60; helo=ozlabs.ru; envelope-from=aik@ozlabs.ru; receiver=) Received: from ozlabs.ru (unknown [107.174.27.60]) by lists.ozlabs.org (Postfix) with ESMTP id 4Hnct05qmnz2yw1 for ; Mon, 8 Nov 2021 15:03:36 +1100 (AEDT) Received: from fstn1-p1.ozlabs.ibm.com. (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id CA4EE8004F; Sun, 7 Nov 2021 23:03:33 -0500 (EST) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH kernel 3/3] powerpc/pseries/ddw: Do not try direct mapping with persistent memory and one window Date: Mon, 8 Nov 2021 15:03:19 +1100 Message-Id: <20211108040320.3857636-4-aik@ozlabs.ru> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211108040320.3857636-1-aik@ozlabs.ru> References: <20211108040320.3857636-1-aik@ozlabs.ru> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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: Frederic Barrat , Brian King , Alexey Kardashevskiy , Leonardo Bras Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" There is a possibility of having just one DMA window available with a limited capacity which the existing code does not handle that well. If the window is big enough for the system RAM but less than MAX_PHYSMEM_BITS (which we want when persistent memory is present), we create 1:1 window and leave persistent memory without DMA. This disables 1:1 mapping entirely if there is persistent memory and either: - the huge DMA window does not cover the entire address space; - the default DMA window is removed. This relies on reverted 54fc3c681ded ("powerpc/pseries/ddw: Extend upper limit for huge DMA window for persistent memory") to return the actual amount RAM in ddw_memory_hotplug_max() (posted separately). Signed-off-by: Alexey Kardashevskiy --- arch/powerpc/platforms/pseries/iommu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index 301fa5b3d528..8f998e55735b 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -1356,8 +1356,10 @@ static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn) len = order_base_2(query.largest_available_block << page_shift); win_name = DMA64_PROPNAME; } else { - direct_mapping = true; - win_name = DIRECT64_PROPNAME; + direct_mapping = !default_win_removed || + (len == MAX_PHYSMEM_BITS) || + (!pmem_present && (len == max_ram_len)); + win_name = direct_mapping ? DIRECT64_PROPNAME : DMA64_PROPNAME; } ret = create_ddw(dev, ddw_avail, &create, page_shift, len); -- 2.30.2