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 5C3654570FF for ; Wed, 23 Sep 2026 07:58:40 +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=1790150322; cv=none; b=OMjRdhIrY4UN4eIWoVq8BCYca0l2ty1/VD5j5wYJiI5v/TVn5nzMKMxce5ZcJPAzaXxL55lzROL17gbFRX/JKF7zCL3ev3ZF7sQ7aFg8QrlnUZJ6wlqNN6B7NyeFVD7P+tYbT1yuQmIn6ixUgiHOgtWn/YU0S3vqDJhts9bu7sI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790150322; c=relaxed/simple; bh=Dk4ell1sggcPNMor+D+EIrp0EtboUTwYE7AbGXYU1fI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:From:In-Reply-To: Content-Type:References; b=r7XtA+w8mlUTPwTsWaMeMyq4rEeEt3Y3cfLrgCmnuXGKlwxJzq+uUKCaIEZAgm8VSkIYYfTkTJHx9JBW4M3pDqvfvjgAP8cpEkuSU4QK9w+sSTBfqNHeSPbIsfs1EraxnuDKCBiqPH6kbtYKlvkN+w0jGTsSgbT9JPlyjkDUGn0= 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=jli3Jpy6; 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="jli3Jpy6" Received: from eucas1p1.samsung.com (unknown [182.198.249.206]) by mailout1.w1.samsung.com (KnoxPortal) with ESMTP id 20260923075831euoutp01cd9ccd8d4cc25b207f6eab023a98445e~X5DlNWNqj2789227892euoutp01K for ; Wed, 23 Sep 2026 07:58:31 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.w1.samsung.com 20260923075831euoutp01cd9ccd8d4cc25b207f6eab023a98445e~X5DlNWNqj2789227892euoutp01K DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1790150311; bh=NLHiHP9oES0/4v1znH/+Y+tVY/g8uuZAdpV7fjYmUCs=; h=Date:Subject:To:Cc:From:In-Reply-To:References:From; b=jli3Jpy6XpcTkS5JhomWNFcZYqqd60JWnlK27Wva6vrjXd+FMvwgRrzLVv+yc44We VYH/3djBt0jSf4mcP8x1Z4Yg9J8tHUwZXXCnohqlEpvwRIlOCX+6sToJtLv7AgvxLW Q3yi+6gtak2IK395VrmKfP1pJ9IapUp5wuBrk8Uw= Received: from eusmtip2.samsung.com (unknown [203.254.199.222]) by eucas1p1.samsung.com (KnoxPortal) with ESMTPA id 20260923075831eucas1p10e4827538fd7f70f278f11157225c07a~X5Dk9kAZT1276212762eucas1p1Y; Wed, 23 Sep 2026 07:58:31 +0000 (GMT) Received: from [106.210.134.192] (unknown [106.210.134.192]) by eusmtip2.samsung.com (KnoxPortal) with ESMTPA id 20260923075830eusmtip24d59db8c7701f60d390302eb88d1b12c~X5Dka9FWj3018730187eusmtip2B; Wed, 23 Sep 2026 07:58:30 +0000 (GMT) Message-ID: Date: Wed, 23 Sep 2026 09:58:30 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Betterbird (Windows) Subject: Re: [PATCH RFC 1/2] iommu/dma: skip swiotlb bounce for DMA_ATTR_MMIO in iommu_dma_map_phys To: "Peng Fan (OSS)" , Robin Murphy , "Joerg Roedel (AMD)" , Will Deacon , Leon Romanovsky , Jason Gunthorpe Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Peng Fan Content-Language: en-US From: Marek Szyprowski In-Reply-To: <20260916-iommu-dma-fix-v1-1-a59a0c45ec5b@nxp.com> Content-Transfer-Encoding: 7bit X-CMS-MailID: 20260923075831eucas1p10e4827538fd7f70f278f11157225c07a X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-RootMTR: 20260916151931eucas1p2f69ddb55e61c8455dedb946b319fb938 X-EPHeader: CA X-CMS-RootMailID: 20260916151931eucas1p2f69ddb55e61c8455dedb946b319fb938 References: <20260916-iommu-dma-fix-v1-0-a59a0c45ec5b@nxp.com> <20260916-iommu-dma-fix-v1-1-a59a0c45ec5b@nxp.com> On 16.09.2026 17:23, Peng Fan (OSS) wrote: > From: Peng Fan > > MMIO resources mapped via dma_map_resource() carry DMA_ATTR_MMIO. These > never need swiotlb bounce buffering, but the current code enters the > swiotlb path when the physical address is not page-aligned, then rejects > the mapping because MMIO cannot be bounced. > > Move the DMA_ATTR_MMIO check before the swiotlb block so the entire bounce > path is skipped for MMIO, falling through directly to __iommu_dma_map() > which creates the IOVA mapping. > > Fixes: f9374de14c0e8 ("iommu/dma: implement DMA_ATTR_MMIO for iommu_dma_(un)map_phys()") > Assisted-by: Claude:claude-opus-4-6 > Signed-off-by: Peng Fan Applied only this patch to dma-mapping-fixes. Thanks! Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland