From nobody Sun Sep 14 08:31:12 2025 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 811C4352096; Tue, 9 Sep 2025 13:29:02 +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=1757424542; cv=none; b=AdFgk2wlowBHt38MODR+/O2LfQA7ei1kzATPHAIiWmQUWAdZ2qhraB3qVrz1Iti6jPNbyrgW/ewhgJsoUj7Pk74WNX9n2nzMpv9jLAizN86SXEgsEy7o4rivrRa294N7ruvez9tqH5aatwqqTX6BleDRhOXHO/LrdBlHPw8e1jw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757424542; c=relaxed/simple; bh=OcM9fkdXGiKETEVH8cBKggBd8afyqoLB0RolB6LyNkA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UtyrFzOeR8eoCqmPQfnOA1e0HGx2UnO2UgXf9IR3TKg6MfNEz9+od49SNBecNYKwoLrX/WXQ88lOhFj2T+PoI1u9HbkylXip0QS5ffLfA3eOSsgtOTQpqSdFiJmZsLEpr8DkNf3M8wNgxs6B5WDjcslrlU74HuB6oeiQ3fTIg5Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Yn9O7EXt; 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="Yn9O7EXt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2DA0AC4CEFB; Tue, 9 Sep 2025 13:29:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757424542; bh=OcM9fkdXGiKETEVH8cBKggBd8afyqoLB0RolB6LyNkA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yn9O7EXt2i8TlTaF6Sd1iT2ojuajj2KIE2jrl5UhotsRQnaPwquEa2I6cD/7jlt78 XzUOKFVinPt3koMpplOVHfrrycPx1YW4URaCTEj9GV17QqK1Icqmm24uElNn4aNE6g dyEXXglk755dAMizt1Low/9xHQbk9wGW/sAxTH/ig1Nx27Rmc511QRKeXmuB4uajDS ry3EbwT8QF9bfs0VlcNQJBaOrGGd32GVtmtPUIlyAl6AFO5fHanUGGe7YyTbMEnZUk af3JTensL0djx/ZctZdYrUUhgTz59dgEpyExsvDCG5MthdUQLFpoXIVWvYnKwiOkhb czV9UQ2BdYnEw== From: Leon Romanovsky To: Marek Szyprowski Cc: Leon Romanovsky , Jason Gunthorpe , Abdiel Janulgue , Alexander Potapenko , Alex Gaynor , Andrew Morton , Christoph Hellwig , Danilo Krummrich , David Hildenbrand , iommu@lists.linux.dev, Jason Wang , Jens Axboe , Joerg Roedel , Jonathan Corbet , Juergen Gross , kasan-dev@googlegroups.com, Keith Busch , linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-nvme@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-trace-kernel@vger.kernel.org, Madhavan Srinivasan , Masami Hiramatsu , Michael Ellerman , "Michael S. Tsirkin" , Miguel Ojeda , Robin Murphy , rust-for-linux@vger.kernel.org, Sagi Grimberg , Stefano Stabellini , Steven Rostedt , virtualization@lists.linux.dev, Will Deacon , xen-devel@lists.xenproject.org Subject: [PATCH v6 09/16] dma-mapping: implement DMA_ATTR_MMIO for dma_(un)map_page_attrs() Date: Tue, 9 Sep 2025 16:27:37 +0300 Message-ID: <3660e2c78ea409d6c483a215858fb3af52cd0ed3.1757423202.git.leonro@nvidia.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Leon Romanovsky Make dma_map_page_attrs() and dma_map_page_attrs() respect DMA_ATTR_MMIO. DMA_ATR_MMIO makes the functions behave the same as dma_(un)map_resource(): - No swiotlb is possible - Legacy dma_ops arches use ops->map_resource() - No kmsan - No arch_dma_map_phys_direct() The prior patches have made the internal functions called here support DMA_ATTR_MMIO. This is also preparation for turning dma_map_resource() into an inline calling dma_map_phys(DMA_ATTR_MMIO) to consolidate the flows. Reviewed-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky --- kernel/dma/mapping.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index e47bcf7cc43d7..95eab531e2273 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -158,6 +158,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struc= t page *page, { const struct dma_map_ops *ops =3D get_dma_ops(dev); phys_addr_t phys =3D page_to_phys(page) + offset; + bool is_mmio =3D attrs & DMA_ATTR_MMIO; dma_addr_t addr; =20 BUG_ON(!valid_dma_direction(dir)); @@ -166,14 +167,25 @@ dma_addr_t dma_map_page_attrs(struct device *dev, str= uct page *page, return DMA_MAPPING_ERROR; =20 if (dma_map_direct(dev, ops) || - arch_dma_map_phys_direct(dev, phys + size)) + (!is_mmio && arch_dma_map_phys_direct(dev, phys + size))) addr =3D dma_direct_map_phys(dev, phys, size, dir, attrs); else if (use_dma_iommu(dev)) addr =3D iommu_dma_map_phys(dev, phys, size, dir, attrs); - else + else if (is_mmio) { + if (!ops->map_resource) + return DMA_MAPPING_ERROR; + + addr =3D ops->map_resource(dev, phys, size, dir, attrs); + } else { + /* + * The dma_ops API contract for ops->map_page() requires + * kmappable memory, while ops->map_resource() does not. + */ addr =3D ops->map_page(dev, page, offset, size, dir, attrs); + } =20 - kmsan_handle_dma(phys, size, dir); + if (!is_mmio) + kmsan_handle_dma(phys, size, dir); trace_dma_map_phys(dev, phys, addr, size, dir, attrs); debug_dma_map_phys(dev, phys, size, dir, addr, attrs); =20 @@ -185,14 +197,18 @@ void dma_unmap_page_attrs(struct device *dev, dma_add= r_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs) { const struct dma_map_ops *ops =3D get_dma_ops(dev); + bool is_mmio =3D attrs & DMA_ATTR_MMIO; =20 BUG_ON(!valid_dma_direction(dir)); if (dma_map_direct(dev, ops) || - arch_dma_unmap_phys_direct(dev, addr + size)) + (!is_mmio && arch_dma_unmap_phys_direct(dev, addr + size))) dma_direct_unmap_phys(dev, addr, size, dir, attrs); else if (use_dma_iommu(dev)) iommu_dma_unmap_phys(dev, addr, size, dir, attrs); - else + else if (is_mmio) { + if (ops->unmap_resource) + ops->unmap_resource(dev, addr, size, dir, attrs); + } else ops->unmap_page(dev, addr, size, dir, attrs); trace_dma_unmap_phys(dev, addr, size, dir, attrs); debug_dma_unmap_phys(dev, addr, size, dir); --=20 2.51.0