From nobody Sun Sep 14 08:31:14 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 BDA873451A8; Tue, 9 Sep 2025 13:29:17 +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=1757424557; cv=none; b=XNTNP9C5ab0E/UZL8ODce2c8roxo7jxar8QHlCzpo7N1ZYUXOhb78BmfkIbsWhgh2GjVPTppVg0rRB6LRM4msXMuOFMQSrVDhDSDC3PpCeARpiw4R9J/h+msVzgzlQk6wiF9tNGgz/bl32wEVw/k7dRpxsz2a+6BmsFiHXanxcM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757424557; c=relaxed/simple; bh=wtwQANAMZgZyvB6tiFp96jG3UeEes+qCqSz/NoS3UPQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BDBQvILc6OcW0GPxaO90mn+IEKB1mGb1DFuIceSJnkTZE8MXK18QiSHeXsJ++Pbq2ZMg9+0Q3YPnsnmtQ+pDfIip7MMFnEGlHZrkVJii205RXGamY/64FvZFQvm0xw4PfV9+Lj6sCTQtfmSu5nsxGIcaiw8oM2DEjIA92K3fVsA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RO8Swnvn; 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="RO8Swnvn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1F67C4CEF5; Tue, 9 Sep 2025 13:29:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757424557; bh=wtwQANAMZgZyvB6tiFp96jG3UeEes+qCqSz/NoS3UPQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RO8SwnvnOfqCFFo/OQtuk43y08F/9NiC0qo46QlPcxTa4eGVUHYLlbxNnl6dZ85H0 x20F6dmOkEPcmpHsf5R+/6fXBIjXKuBiWRMkaWwUQubRdIinqe54Txa6tN8WlX2eCE TjNCykXDXDAKP22rhADMYKKG4IeQ/xdqjUNB9nFAhHvWm8XVmqmTnjP+KsZMgXmxER U9ohR1NuEHfgYDgyAZHMIK03b2sbV6Yt6fuGDW5ZtsOhCz1qoFNEVy4A6MCZp4MaVA K+CH97tUymCL5/6yV3iWa8ebvxIWwf3QpaIqoywL+4IYTWGZmoJfNhPPhhg16fdKRx XixjO6eOuMVKQ== 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 12/16] mm/hmm: migrate to physical address-based DMA mapping API Date: Tue, 9 Sep 2025 16:27:40 +0300 Message-ID: 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 Convert HMM DMA operations from the legacy page-based API to the new physical address-based dma_map_phys() and dma_unmap_phys() functions. This demonstrates the preferred approach for new code that should use physical addresses directly rather than page+offset parameters. The change replaces dma_map_page() and dma_unmap_page() calls with dma_map_phys() and dma_unmap_phys() respectively, using the physical address that was already available in the code. This eliminates the redundant page-to-physical address conversion and aligns with the DMA subsystem's move toward physical address-centric interfaces. This serves as an example of how new code should be written to leverage the more efficient physical address API, which provides cleaner interfaces for drivers that already have access to physical addresses. Reviewed-by: Jason Gunthorpe Signed-off-by: Leon Romanovsky --- mm/hmm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/hmm.c b/mm/hmm.c index d545e24949949..015ab243f0813 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -775,8 +775,8 @@ dma_addr_t hmm_dma_map_pfn(struct device *dev, struct h= mm_dma_map *map, if (WARN_ON_ONCE(dma_need_unmap(dev) && !dma_addrs)) goto error; =20 - dma_addr =3D dma_map_page(dev, page, 0, map->dma_entry_size, - DMA_BIDIRECTIONAL); + dma_addr =3D dma_map_phys(dev, paddr, map->dma_entry_size, + DMA_BIDIRECTIONAL, 0); if (dma_mapping_error(dev, dma_addr)) goto error; =20 @@ -819,8 +819,8 @@ bool hmm_dma_unmap_pfn(struct device *dev, struct hmm_d= ma_map *map, size_t idx) dma_iova_unlink(dev, state, idx * map->dma_entry_size, map->dma_entry_size, DMA_BIDIRECTIONAL, attrs); } else if (dma_need_unmap(dev)) - dma_unmap_page(dev, dma_addrs[idx], map->dma_entry_size, - DMA_BIDIRECTIONAL); + dma_unmap_phys(dev, dma_addrs[idx], map->dma_entry_size, + DMA_BIDIRECTIONAL, 0); =20 pfns[idx] &=3D ~(HMM_PFN_DMA_MAPPED | HMM_PFN_P2PDMA | HMM_PFN_P2PDMA_BUS); --=20 2.51.0