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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 BD003C76188 for ; Fri, 19 Jul 2019 08:07:19 +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 40CBA2084D for ; Fri, 19 Jul 2019 08:07:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="hY4ZF+xW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 40CBA2084D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org 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 45qkBF1HwszDqfK for ; Fri, 19 Jul 2019 18:07:17 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (mailfrom) smtp.mailfrom=bombadil.srs.infradead.org (client-ip=2607:7c80:54:e::133; helo=bombadil.infradead.org; envelope-from=batv+0127b854950d050a2cef+5808+infradead.org+hch@bombadil.srs.infradead.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=infradead.org header.i=@infradead.org header.b="hY4ZF+xW"; dkim-atps=neutral Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45qk8J6S89zDqTk for ; Fri, 19 Jul 2019 18:05:36 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=j6m3dpxjPQBgsve5FxBN1VXYoBHhVQWi8vavLjXXQ1g=; b=hY4ZF+xWw7VgyJbXMBef6njm4 uieIvbJvrktQEv3bl335vW3eC33Mp3HvXaEixDrB8YKz1VLETL3Fz5ezK0rpvE35hc9dmj1s1wiNK hPSxJOFvMxo9iBVrCG/BrnHGodwucUu1gsXYK4fiddTDt1ffgNC52gSbwEJAKwOPyDzOPrEq1A+zK Gt+ziY1HSZr+TJqi32nmWpYtD2LaMcDJx+JCvRU2JEAa7D6NcRChpkOdVSU9g1IYnugS/xunuxgtB rxdiGrMjwhurVGEsSMqxeSiMWkZA46dwuJNsF5T985DlL3Kwjy4X4cJW+FT4J0ccTV+nHgJGL2zAb uaWNiZj2g==; Received: from hch by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hoNtU-0002VN-QO; Fri, 19 Jul 2019 08:05:32 +0000 Date: Fri, 19 Jul 2019 01:05:32 -0700 From: Christoph Hellwig To: Alexey Kardashevskiy Subject: Re: question on "powerpc/pseries/dma: Allow SWIOTLB" Message-ID: <20190719080532.GA3861@infradead.org> References: <20190719071014.GA1922@infradead.org> <0f969485-a3fe-4436-a448-5f4c4f875cb2@ozlabs.ru> <20190719075348.GA2892@infradead.org> <33ba562c-1a87-58e2-4105-520834d5b969@ozlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <33ba562c-1a87-58e2-4105-520834d5b969@ozlabs.ru> User-Agent: Mutt/1.11.4 (2019-03-13) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html 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: Christoph Hellwig , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, Jul 19, 2019 at 06:00:25PM +1000, Alexey Kardashevskiy wrote: > > But shouldn't we force usage of the direct ops in that case as the > > IOMMU is not neededed at all? > > We do, for mappings, but not unmappings and syncing. Well, I mean as in literally not setting a dma_ops so that the dma_direct code is used without the indirection through the iommu ops. This is not only more obvious, but also faster as you avoid the indirect call (although that probably doesn't matter much if you are bounce buffering anyway). > > Also isn't that support non-upstream so far? > > How is this relevant? I expect the existing "swiotlb=force" just work. I though the whole secure VM support was still not upstream.