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 53F7930E0F2; Tue, 19 Aug 2025 17:38:11 +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=1755625091; cv=none; b=YP6bo6gQ4OjjU7ym8xV3GlNwIxSQXnWISifEUc7kIk4li3uSjtm/Cfq60ZHSdCc/g+Oo36OMKDFtszOZFdbWcVGFP0rR0qkZ8MDh7TOsEdLl5cDLz1lrczGaxianch/Bb/H1dLfVtnaNoTOUV2xorQATm8gzkxG76Nkk6i9IcBk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755625091; c=relaxed/simple; bh=6kQRc8M4kSTN6oNlv6UupesxmLI8KrU+a1TL4nhd0iE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lm3orTS3f3I/AkUOV2ngvsE6vIYnosDLM7XVr5XR3dCgFV3QXZBFvR325/QvTyCY50A6CN6hxD4+XmLj6Y1AF8Th/UTuZkjrULx9M2oMYD8yQZ+vKSRQk2JPILACzmrchof0dEz5UAtiGBj5Pz56P9Vh0+12Puoya+NQSOkxQ9U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=f0VJAtsV; 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="f0VJAtsV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0661C4CEF4; Tue, 19 Aug 2025 17:38:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755625091; bh=6kQRc8M4kSTN6oNlv6UupesxmLI8KrU+a1TL4nhd0iE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f0VJAtsVM5u2o6C1nUp18HimKN2EfCmaIhrfHn2QNSc0GqPof7zC6NvZWtW7WxBRR p3RzrCBavtqMekvMpM+FFh/Cujilw/RqORiadfmgV0O0WPFzb3zoh9fG9NtA2SaKoT 4uJuPVNsL+wJyPMLIlFVRwue/XQQMijoKpQiX1gYXGPLJHRcRcKooNhIu/RI+O4xTw brcapoHDidTXn3mbpESixmE7uBDkslSxKOYNfAAHP/Nup/cmkLiUsTvpENQ4pVyy+t J22UXxZ5+SPlhyjgcQ8KrBLrryIlymPi7z68rps63VS+W0pkPza1dnTv8/Usu1mzsw k69P5i9HZUFVA== From: Leon Romanovsky To: Marek Szyprowski Cc: Leon Romanovsky , Jason Gunthorpe , Abdiel Janulgue , Alexander Potapenko , Alex Gaynor , Andrew Morton , Christoph Hellwig , Danilo Krummrich , 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 v4 09/16] dma-mapping: handle MMIO flow in dma_map|unmap_page Date: Tue, 19 Aug 2025 20:36:53 +0300 Message-ID: X-Mailer: git-send-email 2.50.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Leon Romanovsky Extend base DMA page API to handle MMIO flow and follow existing dma_map_resource() implementation to rely on dma_map_direct() only to take DMA direct path. 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 891e1fc3e582..fdabfdaeff1d 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, struct page *page, { const struct dma_map_ops *ops = get_dma_ops(dev); phys_addr_t phys = page_to_phys(page) + offset; + bool is_mmio = attrs & DMA_ATTR_MMIO; dma_addr_t addr; BUG_ON(!valid_dma_direction(dir)); @@ -166,14 +167,25 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, return DMA_MAPPING_ERROR; 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 = dma_direct_map_phys(dev, phys, size, dir, attrs); else if (use_dma_iommu(dev)) addr = iommu_dma_map_phys(dev, phys, size, dir, attrs); - else + else if (is_mmio) { + if (!ops->map_resource) + return DMA_MAPPING_ERROR; + + addr = 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 = ops->map_page(dev, page, offset, size, dir, attrs); + } - 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); @@ -185,14 +197,18 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); + bool is_mmio = attrs & DMA_ATTR_MMIO; 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); -- 2.50.1