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=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 8C188C433DF for ; Thu, 27 Aug 2020 14:46:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66BBB2054F for ; Thu, 27 Aug 2020 14:46:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="tCVVttP1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728093AbgH0Oqt (ORCPT ); Thu, 27 Aug 2020 10:46:49 -0400 Received: from smtp-fw-4101.amazon.com ([72.21.198.25]:17944 "EHLO smtp-fw-4101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727991AbgH0Olh (ORCPT ); Thu, 27 Aug 2020 10:41:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1598539296; x=1630075296; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=unv0Tfgwvb0KrAP7CtFheOrORuCI+KCsaG06ffbe73s=; b=tCVVttP1Bfeg4ipx2aMzXOscAk4Mx0qjZwlbidJfVoWGqwm69I0JwNJ0 Hh+eweloNKKRnollBKD5nEtm7xgTuBxoRHfVJa11psuSwzR3H7jOrfjdV pdjkJCvKy1bSG4qARm9021b3LZ9XN0tFJYMQDXqIRpT+sMohbs5hI6sFi A=; X-IronPort-AV: E=Sophos;i="5.76,359,1592870400"; d="scan'208";a="50441316" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1d-38ae4ad2.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 27 Aug 2020 14:41:35 +0000 Received: from EX13MTAUEE001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-38ae4ad2.us-east-1.amazon.com (Postfix) with ESMTPS id 8F52BA222F; Thu, 27 Aug 2020 14:41:34 +0000 (UTC) Received: from EX13D08UEE001.ant.amazon.com (10.43.62.126) by EX13MTAUEE001.ant.amazon.com (10.43.62.226) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 27 Aug 2020 14:41:33 +0000 Received: from EX13MTAUEA002.ant.amazon.com (10.43.61.77) by EX13D08UEE001.ant.amazon.com (10.43.62.126) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 27 Aug 2020 14:41:33 +0000 Received: from dev-dsk-csbisa-2a-37939146.us-west-2.amazon.com (172.19.34.216) by mail-relay.amazon.com (10.43.61.169) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 27 Aug 2020 14:41:33 +0000 Received: by dev-dsk-csbisa-2a-37939146.us-west-2.amazon.com (Postfix, from userid 800212) id 2ADE31A3; Thu, 27 Aug 2020 14:41:32 +0000 (UTC) Date: Thu, 27 Aug 2020 14:41:32 +0000 From: Clint Sbisa To: Catalin Marinas , Will Deacon CC: Benjamin Herrenschmidt , Ali Saidi , David Woodhouse , Guy Tzalik , , Subject: Re: [PATCH] arm64: Enable PCI write-combine resources under sysfs Message-ID: <20200827144132.ob6ugfrebfgbxwxc@amazon.com> References: <20200821155154.umharcbew46hkhuq@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20200821155154.umharcbew46hkhuq@amazon.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 21, 2020 at 03:51:54PM +0000, Clint Sbisa wrote: > Using write-combine is crucial for performance of PCI devices where > significant amounts of transactions go over PCI BARs. > > arm64 supports write-combine PCI mappings, so the appropriate define > has been added which will expose write-combine mappings under sysfs > for prefetchable PCI resources. > > Signed-off-by: Clint Sbisa > --- > arch/arm64/include/asm/pci.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h > index 70b323cf8300..b33ca260e3c9 100644 > --- a/arch/arm64/include/asm/pci.h > +++ b/arch/arm64/include/asm/pci.h > @@ -17,6 +17,7 @@ > #define pcibios_assign_all_busses() \ > (pci_has_flag(PCI_REASSIGN_ALL_BUS)) > > +#define arch_can_pci_mmap_wc() 1 > #define ARCH_GENERIC_PCI_MMAP_RESOURCE 1 > > extern int isa_dma_bridge_buggy; > -- > 2.23.3 > Ping. Let me know if any more info is needed. Clint