From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9F9E03EF0B8; Mon, 16 Mar 2026 19:07:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773688050; cv=none; b=CGsoYKYlABHtXx32Sz1w2Q9eevxEH8qENdNViN2iI+hEyirvp1a4iJQR1tRQ72F+9DfG3F0T8WVHlujQXTT12aSqYqKb9xOleahEat8iatYGwKV1iA3Hb47k13AXvNK3T/TibC4i5nxVaTKLzAjiwhL/WAFvLt0kS/NkdYUGp9w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773688050; c=relaxed/simple; bh=aXwCdr26DGL4+NaZEE3PT+YDkt3E2yVN7za/ReeSxow=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=a84LPs3i3nZ3lyq2832cfJ1ZPeiSUJy6UiBlrAKWAhnT9gkk9d95tCIOpw7Y9xJjx0TrcqrYIPGa3cznUkuz620FC0eBMO0isxVAvDcGdDSEb/GDVVAVSUyVj/rSb2As7NtD1Glu9rq9Z9xiDCBkfAqugeQiT5dvBnhLmy2R7go= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qShwIFNF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qShwIFNF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05BF4C19421; Mon, 16 Mar 2026 19:07:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773688050; bh=aXwCdr26DGL4+NaZEE3PT+YDkt3E2yVN7za/ReeSxow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qShwIFNFGuszc3wiBhUM/dXxzghLUfqSxNk6dSgejFCa16sP7mJ0YnF6nuboDJQ0I V1hdbvS1Cw4Q8UMNmIyZewdSbxL6PjFsKqY3LNx7tSYGdDqKW1taN6l2fo9mdtgC8y iHvFgLqcBiNy7tYnGM7quwPT+cd6RXOSvqXFQIO3R0aHDLowDG6fgtIPenYBLlYyQi 8npPn1RHBtah/rBZsE9wx+ixSFiZXVoxr3c+0eLM5qx/BZ1L86QMlxbXrzlzw+5VLo owZUj8Y7VbcTo2sOQlqSsHYt9BPLxuC7yd10mWvitREI5onnc8psViY7rBblB38Pad i7l8YW5XaRDUA== From: Leon Romanovsky To: Marek Szyprowski , Robin Murphy , "Michael S. Tsirkin" , Petr Tesarik , Jonathan Corbet , Shuah Khan , Jason Wang , Xuan Zhuo , =?utf-8?q?Eugenio_P=C3=A9rez?= , Jason Gunthorpe , Leon Romanovsky , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Joerg Roedel , Will Deacon , Andrew Morton Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, virtualization@lists.linux.dev, linux-rdma@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 6/8] iommu/dma: add support for DMA_ATTR_REQUIRE_COHERENT attribute Date: Mon, 16 Mar 2026 21:06:50 +0200 Message-ID: <20260316-dma-debug-overlap-v3-6-1dde90a7f08b@nvidia.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260316-dma-debug-overlap-v3-0-1dde90a7f08b@nvidia.com> References: <20260316-dma-debug-overlap-v3-0-1dde90a7f08b@nvidia.com> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" X-Mailer: b4 0.15-dev-18f8f Content-Transfer-Encoding: 8bit From: Leon Romanovsky Add support for the DMA_ATTR_REQUIRE_COHERENT attribute to the exported functions. This attribute indicates that the SWIOTLB path must not be used and that no sync operations should be performed. Signed-off-by: Leon Romanovsky --- drivers/iommu/dma-iommu.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 5dac64be61bb2..94d5141696424 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -1211,7 +1211,7 @@ dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size, */ if (dev_use_swiotlb(dev, size, dir) && iova_unaligned(iovad, phys, size)) { - if (attrs & DMA_ATTR_MMIO) + if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT)) return DMA_MAPPING_ERROR; phys = iommu_dma_map_swiotlb(dev, phys, size, dir, attrs); @@ -1223,7 +1223,8 @@ dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size, arch_sync_dma_for_device(phys, size, dir); iova = __iommu_dma_map(dev, phys, size, prot, dma_mask); - if (iova == DMA_MAPPING_ERROR && !(attrs & DMA_ATTR_MMIO)) + if (iova == DMA_MAPPING_ERROR && + !(attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))) swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs); return iova; } @@ -1233,7 +1234,7 @@ void iommu_dma_unmap_phys(struct device *dev, dma_addr_t dma_handle, { phys_addr_t phys; - if (attrs & DMA_ATTR_MMIO) { + if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT)) { __iommu_dma_unmap(dev, dma_handle, size); return; } @@ -1945,9 +1946,21 @@ int dma_iova_link(struct device *dev, struct dma_iova_state *state, if (WARN_ON_ONCE(iova_start_pad && offset > 0)) return -EIO; + /* + * DMA_IOVA_USE_SWIOTLB is set on state after some entry + * took SWIOTLB path, which we were supposed to prevent + * for DMA_ATTR_REQUIRE_COHERENT attribute. + */ + if (WARN_ON_ONCE((state->__size & DMA_IOVA_USE_SWIOTLB) && + (attrs & DMA_ATTR_REQUIRE_COHERENT))) + return -EOPNOTSUPP; + + if (!dev_is_dma_coherent(dev) && (attrs & DMA_ATTR_REQUIRE_COHERENT)) + return -EOPNOTSUPP; + if (dev_use_swiotlb(dev, size, dir) && iova_unaligned(iovad, phys, size)) { - if (attrs & DMA_ATTR_MMIO) + if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT)) return -EPERM; return iommu_dma_iova_link_swiotlb(dev, state, phys, offset, -- 2.53.0