From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout1.w1.samsung.com (mailout1.w1.samsung.com [210.118.77.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 97D1328314D for ; Tue, 8 Jul 2025 10:27:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.118.77.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751970443; cv=none; b=WaYagUQFl0dqQ2xSMRqqqlI9iKnV01K3aN6I3aCljAn3KthgLZOq8fXcc0TSd4xe1hOiiSy1jG77p+kx6qNuVbmSogvFIOC4x0Nz3gXfODA6io7vtNVEmmkStQkBkcuThpxMhQk5V90jNQIhS7olctxPmb1h7iAI8L41skOXxQM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751970443; c=relaxed/simple; bh=14manGusg8Qgqx1rKMesK88ejf15XhHcScCCmKXCkgk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:From:In-Reply-To: Content-Type:References; b=FPaMU4tvx7mxXany6DyzXVHtrgGbio0/Uqey3ff6eBthYUHyL6OelCH6t3ykoaYqM2v6LHhpE+bmoEg82EtktVrYX1S9rfzc0ALnNIRQGB5KRXIBQO6tigNOoD/7qQfujTXvGKaBwzDgJ05JIGsCQrz2IGRMra4GHlm7Wq+jBsk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=goyCVYPT; arc=none smtp.client-ip=210.118.77.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="goyCVYPT" Received: from eucas1p2.samsung.com (unknown [182.198.249.207]) by mailout1.w1.samsung.com (KnoxPortal) with ESMTP id 20250708102712euoutp01f0e39562a866c70252ebe961ce6a263b~QP9OTbAap2622426224euoutp01c for ; Tue, 8 Jul 2025 10:27:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.w1.samsung.com 20250708102712euoutp01f0e39562a866c70252ebe961ce6a263b~QP9OTbAap2622426224euoutp01c DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1751970433; bh=CvHwMYp2XIGbJnf/9QWS8C8NtBZtZV/va6aW8p1Pd0k=; h=Date:Subject:To:Cc:From:In-Reply-To:References:From; b=goyCVYPTGJec31NpQ9MuiZWPNwVsd9Tmt+dtufXuoWH9fESY6GRmHCV3IogYjxBwH FW8wi7eGBCXxHU70+QuQ5gt30FB8PoRsvUbcIZug6xKW+KWkUZqnck9E+kKu8ENViC LMtHzrZh60YIQnqMgYskMSyViJ/QRqZzQZ1yrD5A= Received: from eusmtip1.samsung.com (unknown [203.254.199.221]) by eucas1p1.samsung.com (KnoxPortal) with ESMTPA id 20250708102712eucas1p1199b906d3c40b7ff5066a92aacd7b14c~QP9NsRWhM2715427154eucas1p1l; Tue, 8 Jul 2025 10:27:12 +0000 (GMT) Received: from [106.210.134.192] (unknown [106.210.134.192]) by eusmtip1.samsung.com (KnoxPortal) with ESMTPA id 20250708102710eusmtip12ad336592b93f91919ed398faf3d4122~QP9LytFDz1124711247eusmtip1B; Tue, 8 Jul 2025 10:27:10 +0000 (GMT) Message-ID: <69b177dc-c149-40d3-bbde-3f6bad0efd0e@samsung.com> Date: Tue, 8 Jul 2025 12:27:09 +0200 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/8] dma-mapping: migrate to physical address-based API To: Christoph Hellwig , Leon Romanovsky Cc: Jonathan Corbet , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Robin Murphy , Joerg Roedel , Will Deacon , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Alexander Potapenko , Marco Elver , Dmitry Vyukov , Masami Hiramatsu , Mathieu Desnoyers , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Andrew Morton , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, iommu@lists.linux.dev, virtualization@lists.linux.dev, kasan-dev@googlegroups.com, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, Jason Gunthorpe Content-Language: en-US From: Marek Szyprowski In-Reply-To: <20250630133839.GA26981@lst.de> Content-Transfer-Encoding: 7bit X-CMS-MailID: 20250708102712eucas1p1199b906d3c40b7ff5066a92aacd7b14c X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20250625131920eucas1p271b196cde042bd39ac08fb12beff5baf X-EPHeader: CA X-CMS-RootMailID: 20250625131920eucas1p271b196cde042bd39ac08fb12beff5baf References: <35df6f2a-0010-41fe-b490-f52693fe4778@samsung.com> <20250627170213.GL17401@unreal> <20250630133839.GA26981@lst.de> On 30.06.2025 15:38, Christoph Hellwig wrote: > On Fri, Jun 27, 2025 at 08:02:13PM +0300, Leon Romanovsky wrote: >>> Thanks for this rework! I assume that the next step is to add map_phys >>> callback also to the dma_map_ops and teach various dma-mapping providers >>> to use it to avoid more phys-to-page-to-phys conversions. >> Probably Christoph will say yes, however I personally don't see any >> benefit in this. Maybe I wrong here, but all existing .map_page() >> implementation platforms don't support p2p anyway. They won't benefit >> from this such conversion. > I think that conversion should eventually happen, and rather sooner than > later. Agreed. Applied patches 1-7 to my dma-mapping-next branch. Let me know if one needs a stable branch with it. Leon, it would be great if You could also prepare an incremental patch adding map_phys callback to the dma_maps_ops, so the individual arch-specific dma-mapping providers can be then converted (or simplified in many cases) too. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland