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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 2C6C6C43461 for ; Mon, 14 Sep 2020 22:32:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6AD9208E4 for ; Mon, 14 Sep 2020 22:32:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="g+WX87et" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725985AbgINWcf (ORCPT ); Mon, 14 Sep 2020 18:32:35 -0400 Received: from smtp-fw-9101.amazon.com ([207.171.184.25]:51099 "EHLO smtp-fw-9101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725953AbgINWcf (ORCPT ); Mon, 14 Sep 2020 18:32:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1600122755; x=1631658755; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=9a01/1QzXUilHHgV2KxnbyNEVyibCeomZvuXR569iKM=; b=g+WX87etT0fPEjw5FeqjFT+wdGDR+jWD41nWN2rOoiQ14rCU6/UUioIm OThOoDFflacbNoQpDNltQ6gHz6SfDh2OrxKuB+HxTJIRvvbmscAuQF6CF c22+UulmtxNc+x7uqqx7BUWMJlRETs7u4n3B+wsZi3yqM1tNUHohvMsgc w=; X-IronPort-AV: E=Sophos;i="5.76,427,1592870400"; d="scan'208";a="67957877" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-2b-c7131dcf.us-west-2.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9101.sea19.amazon.com with ESMTP; 14 Sep 2020 22:32:24 +0000 Received: from EX13MTAUWC001.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2b-c7131dcf.us-west-2.amazon.com (Postfix) with ESMTPS id 62990A0716; Mon, 14 Sep 2020 22:32:23 +0000 (UTC) Received: from EX13D02UWC003.ant.amazon.com (10.43.162.199) by EX13MTAUWC001.ant.amazon.com (10.43.162.135) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 14 Sep 2020 22:32:22 +0000 Received: from EX13MTAUWC001.ant.amazon.com (10.43.162.135) by EX13D02UWC003.ant.amazon.com (10.43.162.199) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 14 Sep 2020 22:32:22 +0000 Received: from dev-dsk-csbisa-2a-37939146.us-west-2.amazon.com (172.19.34.216) by mail-relay.amazon.com (10.43.162.232) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 14 Sep 2020 22:32:22 +0000 Received: by dev-dsk-csbisa-2a-37939146.us-west-2.amazon.com (Postfix, from userid 800212) id 6C83C192; Mon, 14 Sep 2020 22:32:21 +0000 (UTC) Date: Mon, 14 Sep 2020 22:32:21 +0000 From: Clint Sbisa To: Benjamin Herrenschmidt CC: Jason Gunthorpe , Lorenzo Pieralisi , , Bjorn Helgaas , , , , Leon Romanovsky Subject: Re: [PATCH] arm64: Enable PCI write-combine resources under sysfs Message-ID: <20200914223221.wqcrwefgms2fuoo2@amazon.com> References: <20200910171033.GG904879@nvidia.com> <44acc22377958a57c738f5139c5b5df2841c2544.camel@kernel.crashing.org> <20200910232938.GJ904879@nvidia.com> <3110e00a1f4df7b7359ba4f2b7f86a35aa47405e.camel@kernel.crashing.org> <20200911214225.hml2wbbq2rofn4re@amazon.com> <20200914141726.GA904879@nvidia.com> <20200914142406.k44zrnp2wdsandsp@amazon.com> <20200914143819.GC904879@nvidia.com> <375c478593945a416f3180c3773bcb5240d2e36c.camel@kernel.crashing.org> <1d6f2ceb8d3538c906a1fdb8cd3d4c74ccffa42e.camel@kernel.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1d6f2ceb8d3538c906a1fdb8cd3d4c74ccffa42e.camel@kernel.crashing.org> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Sep 15, 2020 at 08:00:27AM +1000, Benjamin Herrenschmidt wrote: > On Tue, 2020-09-15 at 07:42 +1000, Benjamin Herrenschmidt wrote: > > > > > which is back to my original question, how do you do DMA using > > > /sys/xx/resources? Why not use VFIO like everything else? > > > > Note: All this doesnt' change the fact that sys/xx/resources_wc > > exists > > for other archs and I see no reasons so far not to have it on ARM... > > Also... it looks like VFIO also doesn't provide a way to do WC yet > unfortunately :-( > > There was a discussion 2 or 3 years ago while I was at IBM about ways > to add that functionality, but it doesn't seem to have resulted in > anything. And to complete answering the question, the ENA PMD in DPDK also supports vfio, which-- as Ben pointed out-- doesn't support WC either. Clint 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=-4.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_ALL,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 3FC0FC433E2 for ; Mon, 14 Sep 2020 22:34:10 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 C5B0B208DB for ; Mon, 14 Sep 2020 22:34:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="zUWRCry5"; 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14 Sep 2020 22:32:24 +0000 Received: from EX13MTAUWC001.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2b-c7131dcf.us-west-2.amazon.com (Postfix) with ESMTPS id 62990A0716; Mon, 14 Sep 2020 22:32:23 +0000 (UTC) Received: from EX13D02UWC003.ant.amazon.com (10.43.162.199) by EX13MTAUWC001.ant.amazon.com (10.43.162.135) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 14 Sep 2020 22:32:22 +0000 Received: from EX13MTAUWC001.ant.amazon.com (10.43.162.135) by EX13D02UWC003.ant.amazon.com (10.43.162.199) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 14 Sep 2020 22:32:22 +0000 Received: from dev-dsk-csbisa-2a-37939146.us-west-2.amazon.com (172.19.34.216) by mail-relay.amazon.com (10.43.162.232) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 14 Sep 2020 22:32:22 +0000 Received: by dev-dsk-csbisa-2a-37939146.us-west-2.amazon.com (Postfix, from userid 800212) id 6C83C192; Mon, 14 Sep 2020 22:32:21 +0000 (UTC) Date: Mon, 14 Sep 2020 22:32:21 +0000 From: Clint Sbisa To: Benjamin Herrenschmidt Subject: Re: [PATCH] arm64: Enable PCI write-combine resources under sysfs Message-ID: <20200914223221.wqcrwefgms2fuoo2@amazon.com> References: <20200910171033.GG904879@nvidia.com> <44acc22377958a57c738f5139c5b5df2841c2544.camel@kernel.crashing.org> <20200910232938.GJ904879@nvidia.com> <3110e00a1f4df7b7359ba4f2b7f86a35aa47405e.camel@kernel.crashing.org> <20200911214225.hml2wbbq2rofn4re@amazon.com> <20200914141726.GA904879@nvidia.com> <20200914142406.k44zrnp2wdsandsp@amazon.com> <20200914143819.GC904879@nvidia.com> <375c478593945a416f3180c3773bcb5240d2e36c.camel@kernel.crashing.org> <1d6f2ceb8d3538c906a1fdb8cd3d4c74ccffa42e.camel@kernel.crashing.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1d6f2ceb8d3538c906a1fdb8cd3d4c74ccffa42e.camel@kernel.crashing.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200914_183236_122301_3279EE56 X-CRM114-Status: GOOD ( 16.51 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lorenzo Pieralisi , Leon Romanovsky , linux-pci@vger.kernel.org, Bjorn Helgaas , Jason Gunthorpe , catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Sep 15, 2020 at 08:00:27AM +1000, Benjamin Herrenschmidt wrote: > On Tue, 2020-09-15 at 07:42 +1000, Benjamin Herrenschmidt wrote: > > > > > which is back to my original question, how do you do DMA using > > > /sys/xx/resources? Why not use VFIO like everything else? > > > > Note: All this doesnt' change the fact that sys/xx/resources_wc > > exists > > for other archs and I see no reasons so far not to have it on ARM... > > Also... it looks like VFIO also doesn't provide a way to do WC yet > unfortunately :-( > > There was a discussion 2 or 3 years ago while I was at IBM about ways > to add that functionality, but it doesn't seem to have resulted in > anything. And to complete answering the question, the ENA PMD in DPDK also supports vfio, which-- as Ben pointed out-- doesn't support WC either. Clint _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel