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 D82BD30C34F; Thu, 14 Aug 2025 17:54:47 +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=1755194088; cv=none; b=euxG5iFXLwxtToxWra3AjeoJG9STxqt2JPFO373eJs8uAXa7cmieToB1D4gh3VMutyu7GuzmHBKiE6C2RUxZ/OCS41rZCmy5+21nk9l9u9sm9zlCDza20kxc0na96xl0iOwzXPDOS2leNKvJESQFuh01ARL3v1K0nE/gsGgxP3Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755194088; c=relaxed/simple; bh=6kQRc8M4kSTN6oNlv6UupesxmLI8KrU+a1TL4nhd0iE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gQE/IzM2DWnPZjoS8CvhptxYUtW0KlxcHKGLhEDDisOXMB8e/Q0De3312E83+uOwUMjEpoqqL+7D8rdBPpfYhYgbwMajH4k+oTGq2ziJN1KEWrP5ESEYHiBT9uoGpdMtmpouh7z/7I0s381fxFL/2YFTgCOGvAgb0cimFrPFrjw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C6w4ugQY; 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="C6w4ugQY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8F749C4CEF6; Thu, 14 Aug 2025 17:54:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755194087; bh=6kQRc8M4kSTN6oNlv6UupesxmLI8KrU+a1TL4nhd0iE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C6w4ugQYiUdcIBDBap/wpiQAIwZla3sL70dXT7fdDwlS8iAo7WkvllaYcXF4QU2M9 kt4WEnzYrIn4ZDZURbuikMUlP1Qp9CxkQOq+obTZHosuKzmVJJ0AF/lK9fQSX5YtoJ kzMxjlyIoIy5MaeVth9MfY0uS93UJW4vr922gEZKEo2egnsKAq7kg8ZgHQF2XBxqCZ F1uVGjeU46DFgcCqPy+lW15qydDCb2UvhK7t93bEVpZBLmZ+yVMS129GxQ41QBkFWL CFslA3zPU9Peu4BjTd3+d/0rvdaudAz+bJ7W9WzhuA5hIM9mliO10n+CPNH4ALRsGy OQQa8odedrzVg== 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 v3 09/16] dma-mapping: handle MMIO flow in dma_map|unmap_page Date: Thu, 14 Aug 2025 20:54:00 +0300 Message-ID: X-Mailer: git-send-email 2.50.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-doc@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