From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 36161339A8 for ; Mon, 24 Nov 2025 17:15:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764004554; cv=none; b=dQf9pbnjpV/4E1UwptoC8yldrCEWxuyXM7qfNBeird/y4g/R/fBVvihzEnshbhMZ4mEcjDH8lplYpGJVF/+QN3ju66T6myLWZehW+JKDqtxXiIYt6ZZqNJ0ctpnE8wukVDevFESLfyt5qupxCEZdblo5SUllhO9Xd+aAuuxLJ5E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764004554; c=relaxed/simple; bh=jyrkAwsHquVNMj6V3U39Yxg1FlqYcxSpFBfPIrWLr6w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=eV2JHzVDSVB+SOqmo1Vkk20FfYolC8jB7L4mmgI9BjfIleFDI63TxKXl6vzMGrqgBx7GzcafldXG/FhSdU3fdgk/S48bf4jdBKaPRFcC/ng0oEBqcxxZmwFIyVDw34thYN4hHZwnYvBG9bVq3ibRXu1q29F/6avVNZHImbIxajQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 32F121477; Mon, 24 Nov 2025 09:15:44 -0800 (PST) Received: from [10.1.30.67] (unknown [10.1.30.67]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 02E353F73B; Mon, 24 Nov 2025 09:15:49 -0800 (PST) Message-ID: <0b214028-299b-46aa-8d98-0f789153c612@arm.com> Date: Mon, 24 Nov 2025 17:15:48 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] iommu/dma: add missing support for DMA_ATTR_MMIO for dma_iova_unlink() To: Marek Szyprowski , iommu@lists.linux.dev, linux-kernel@vger.kernel.org Cc: Joerg Roedel , Will Deacon , Leon Romanovsky , Jason Gunthorpe References: <20251124170955.3884351-1-m.szyprowski@samsung.com> From: Robin Murphy Content-Language: en-GB In-Reply-To: <20251124170955.3884351-1-m.szyprowski@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2025-11-24 5:09 pm, Marek Szyprowski wrote: > Commit c288d657dd51 added support for DMA_ATTR_MMIO attribute in the > dma_iova_link() code path, but missed that the CPU cache is being also > touched in the dma_iova_unlink() path. Fix this. > > Fixes: c288d657dd51 ("iommu/dma: implement DMA_ATTR_MMIO for dma_iova_link().") > Signed-off-by: Marek Szyprowski > --- > drivers/iommu/dma-iommu.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index e52d19d2e833..c92088855450 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -2008,7 +2008,7 @@ static void iommu_dma_iova_unlink_range_slow(struct device *dev, > end - addr, iovad->granule - iova_start_pad); > > if (!dev_is_dma_coherent(dev) && > - !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) > + !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO))) > arch_sync_dma_for_cpu(phys, len, dir); > > swiotlb_tbl_unmap_single(dev, phys, len, dir, attrs); > @@ -2032,7 +2032,8 @@ static void __iommu_dma_iova_unlink(struct device *dev, > size_t unmapped; > > if ((state->__size & DMA_IOVA_USE_SWIOTLB) || > - (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))) > + (!dev_is_dma_coherent(dev) && > + !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO)))) This isn't needed, since there's no way an MMIO mapping could have used SWIOTLB. Thanks, Robin. > iommu_dma_iova_unlink_range_slow(dev, addr, size, dir, attrs); > > iommu_iotlb_gather_init(&iotlb_gather);