From patchwork Wed Feb 5 14:40:28 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Romanovsky X-Patchwork-Id: 13961204 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 875491DD87D; Wed, 5 Feb 2025 14:41:22 +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=1738766482; cv=none; b=XfGZBSMFItx6uLaa1JHu7OK5SQgHHFOs2VkWyIlk9N/v4RqHYoO8I3yAqiizS/z9HdxNrTvq2JkIN+l9JU1QEP4xH5m30WjcTOomFCCPy2IwdJV3bjAyDLXpJttafYgZmUp6we4rTLhupft1R2NRoRWPSqVwgn9c682kVZmtloI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738766482; c=relaxed/simple; bh=h/yBzjhoClTiKMl8LmMlOxeyuG0iINYdLuYFXO+3beM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=S26vj/In+a1i8v97F/NBU0mHxHnOD3fFVdkxtP3aAzzCkImbUVYiAgdZ7XLMWQYh6ro/zD8Rn7nolQ9kdniwk4zhOGvORXB1OCc81IBB54CDvkrowqEJezGPzs7wJXguA4ArjwMmvhA6Qx8SW/Qbs0HXMdrsr9LUqF/HqEga20w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EQyxrQTb; 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="EQyxrQTb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E0BCC4CEDD; Wed, 5 Feb 2025 14:41:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738766482; bh=h/yBzjhoClTiKMl8LmMlOxeyuG0iINYdLuYFXO+3beM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EQyxrQTbpGC5ELIJR6leSqpKifyAyAeb8I25BfLUz1ZlNtPRHHXvoAx88ZmrkyhEj oiWitEtgqYTOWTpFkQbSoNIgY697J6MH3fgUibpLubW6kyqypRIhWVHQGweM5VjovX Y1kC2pXK7i3BJenUde3znE6Y9+xI1LxPrSgIzVCpeRFAFE2Mk+Y2KOQSzJRqpjmsik lZLP6NauWc5PCH6knOGMgYGQ2xZ4Jq10wd5UPj6rUnemzBirIatwxYpFvbihAfjv4l iAoBLOEQbRc5Y/oScO3iFxYYMiLToSeN6xqr8mVzjSijcHqG6FQdSWfyW/ezi5a2FL 0IJKIrd4mwf4A== From: Leon Romanovsky To: Christoph Hellwig , Jason Gunthorpe , Robin Murphy Cc: Jens Axboe , Joerg Roedel , Will Deacon , Sagi Grimberg , Keith Busch , Bjorn Helgaas , Logan Gunthorpe , Yishai Hadas , Shameer Kolothum , Kevin Tian , Alex Williamson , Marek Szyprowski , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Andrew Morton , Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-rdma@vger.kernel.org, iommu@lists.linux.dev, linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, Randy Dunlap Subject: [PATCH v7 08/17] dma-mapping: add a dma_need_unmap helper Date: Wed, 5 Feb 2025 16:40:28 +0200 Message-ID: <6c134d9e273433c52ca406de30112ecbc13f3b88.1738765879.git.leonro@nvidia.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Christoph Hellwig Add helper that allows a driver to skip calling dma_unmap_* if the DMA layer can guarantee that they are no-nops. Signed-off-by: Christoph Hellwig Signed-off-by: Leon Romanovsky --- include/linux/dma-mapping.h | 5 +++++ kernel/dma/mapping.c | 18 ++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index a71e110f1e9d..d2f358c5a25d 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -406,6 +406,7 @@ static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) { return dma_dev_need_sync(dev) ? __dma_need_sync(dev, dma_addr) : false; } +bool dma_need_unmap(struct device *dev); #else /* !CONFIG_HAS_DMA || !CONFIG_DMA_NEED_SYNC */ static inline bool dma_dev_need_sync(const struct device *dev) { @@ -431,6 +432,10 @@ static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) { return false; } +static inline bool dma_need_unmap(struct device *dev) +{ + return false; +} #endif /* !CONFIG_HAS_DMA || !CONFIG_DMA_NEED_SYNC */ struct page *dma_alloc_pages(struct device *dev, size_t size, diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index cda127027e48..3c3204ad2839 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -443,6 +443,24 @@ bool __dma_need_sync(struct device *dev, dma_addr_t dma_addr) } EXPORT_SYMBOL_GPL(__dma_need_sync); +/** + * dma_need_unmap - does this device need dma_unmap_* operations + * @dev: device to check + * + * If this function returns %false, drivers can skip calling dma_unmap_* after + * finishing an I/O. This function must be called after all mappings that might + * need to be unmapped have been performed. + */ +bool dma_need_unmap(struct device *dev) +{ + if (!dma_map_direct(dev, get_dma_ops(dev))) + return true; + if (!dev->dma_skip_sync) + return true; + return IS_ENABLED(CONFIG_DMA_API_DEBUG); +} +EXPORT_SYMBOL_GPL(dma_need_unmap); + static void dma_setup_need_sync(struct device *dev) { const struct dma_map_ops *ops = get_dma_ops(dev);