From nobody Sat Oct 4 17:30:14 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 A7E5F3090D9; Thu, 14 Aug 2025 10:14:40 +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=1755166480; cv=none; b=Q7DirXQC28puT4w4vD4xcT8zkUdrwFFu8wdaedhgQVVtrNPF5on3vtBK7CBTFz9RvtnIWW6lsOQFJvtEmJ/q0A1aV6EfpWuCQFcpHa81oabXncJ4j40RKtC0kUAQhd3jakB/hN7bqoVGQTH+ujYuyWZuH0oP0d4ohRvVSWpGqmw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755166480; c=relaxed/simple; bh=O9XZOHlHvjORXmOt4kTIQrFLHTrONFqw1ae8lUbcYw8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Bjpqa78OlLS+SeNN03aWUZ84xG9UXGOXUfi1gaLEygxVS2RNYddOZrmcass8Z5T+FuM0QXbExFWDeNMm0joBO124kCucTBsUIYJVWNaWSOgNhExQuiW1S8rMvouKUfp1bPJXCxbnCY3qckRzowtQWRxfNPo7Y95eSis1QtpjrEE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eWNP8pfq; 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="eWNP8pfq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27028C4CEED; Thu, 14 Aug 2025 10:14:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755166480; bh=O9XZOHlHvjORXmOt4kTIQrFLHTrONFqw1ae8lUbcYw8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eWNP8pfq7yUM25kUsbm3T+cq953aNotFNHBqMxVlWCtlUYOt5Rw3JG6yLlkJyNYia 0DPFRhoAzA9uIWb4p7LPAYf9xIZ391Hkz/Tpf2xoI+iUWSIU2W7lzjQ54XlYOKvAbM b6GPu27TSwCixhdzxPCCW+NF4MA4gs0/au8J3ut9S/JCFvIyeiBlUMgoXmOuZQu/o4 Wnziz3n69of8QUiKZhOoPQzzbBclfAGwMqIbjxwm2VdCvmOPiOo0ennsGFEuIXJEy/ dMZv2hpRL9zGOuGaoy7hht/3GW82juz30t3Cp/uMMdSOa2W43Gw2TJip6DKEh1GJ+X yPFpfFYdC1pBA== 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 v2 12/16] mm/hmm: migrate to physical address-based DMA mapping API Date: Thu, 14 Aug 2025 13:13:30 +0300 Message-ID: <259668e7a332148edf8738b7b4637c2b264f51ea.1755153054.git.leon@kernel.org> X-Mailer: git-send-email 2.50.1 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 d545e2494994..015ab243f081 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 2.50.1