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=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 DC263CA9EAF for ; Thu, 24 Oct 2019 11:11:10 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 A1A8720684 for ; Thu, 24 Oct 2019 11:11:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="BTCRFMag"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="BM4kF8Em" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A1A8720684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 4E6EF14C0; Thu, 24 Oct 2019 11:11:10 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E17D314AD for ; Thu, 24 Oct 2019 11:11:08 +0000 (UTC) Received: from smtp.codeaurora.org (smtp.codeaurora.org [198.145.29.96]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 978598C0 for ; Thu, 24 Oct 2019 11:11:08 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1000) id F2AD760FCE; Thu, 24 Oct 2019 11:11:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1571915468; bh=hmGbZeOmKr4VCEmEhi6phLPSxbiaCdDN+JSzwdHE3To=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=BTCRFMagOlXRviHjH0UyHMz5cBjB7kHi+r/w+AUobvnYyDiAoSmDDciaVoC5i34Mh fYAmy4OAcBzt6k/FZ7mL9kU/4nro+qj45XM4UMn1VfD/uC/HiTY5TLT9IR7Z5AeRPE vJsbvuagSE9Z6vj3RX18idbqUfDm139u3dmdtqh4= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 97AD160D9D; Thu, 24 Oct 2019 11:11:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1571915465; bh=hmGbZeOmKr4VCEmEhi6phLPSxbiaCdDN+JSzwdHE3To=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=BM4kF8Emizm6YwAYeiCpuuGv8T5OQjbt/fvV7r6kgZA8TBglhWxBB5knVtA7zgaDY kGNpDEHoHpOZf5NZHawtTR7ZWnrPnXmU9gOxSEpXjxZ5Z4cDMG03WTuFq91toj6XmX PPcuWbIrg/OtSLsA5lJRXJconhIpiNW/hrt5l9NY= MIME-Version: 1.0 Date: Thu, 24 Oct 2019 16:41:04 +0530 From: Sai Prakash Ranjan To: Will Deacon Subject: Re: Users of IOMMU_QCOM_SYS_CACHE? In-Reply-To: <20191024105150.GC1242@willie-the-truck> References: <20191024105150.GC1242@willie-the-truck> Message-ID: X-Sender: saiprakash.ranjan@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Cc: iommu@lists.linux-foundation.org, robin.murphy@arm.com, sspatil@android.com X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Hi Will, On 2019-10-24 16:21, Will Deacon wrote: > Hi all, > > In commit 90ec7a76cc4b ("iommu/io-pgtable-arm: Add support to use > system > cache") we added support for IOMMU_QCOM_SYS_CACHE which was merged into > 5.3. > This allows non-coherent devices to request an outer cacheable memory > type.... except that nobody actually does this in mainline. I remember > there > being a potential DRM user but I don't know what happened to it. > > Given that this isn't actually exposed in the DMA API, I worry that > we're > just carrying part of an out-of-tree hack here and propose that we drop > the flag altogether unless we get an upstream user, preferably by > plumbing > this into the DMA API via a new attribute. > > Thoughts? > There is definitely a user of this coming soon atleast for SC7180 SoC once we have support for this SoC upstream. -Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu