From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 97017C369CB for ; Wed, 23 Apr 2025 11:15:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4p0kO8ATaV+1xaor/N8Kky8TfT5sQxFrqD4r1YS307Q=; b=ci1HkzfW9DOSTUFvY82VdiOs9O D0H6xpdP11QwejhZrh+yztViKRGF/hMzutUCGexEOaGVcQ0EaZ0qBQ7JjCg4c6XsMJFuoha3Qo5VI wJTEx/3ZmoWR4GLDjsj+lS4KASWL0krjtCk5kGwZMcxIgTwnGTxcBEYK9qyHk1UTIQ7gXGUskgIIx wg5uIezdhFo7XRqn6qiSezKSIVdJ/Dv4BtoXfwSwg6gl0cLibYKhsaxeO1liI534lwawnEYmpJvNi V5wudUMSHZ9owzqc1fnxtxwvPSjGIVJb4/1EXYcoeKJ/7mwlS9InbwfiZcsBGGKltmfjI+/Rrhga/ ra8yth1w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u7Y4n-0000000AHcr-3PmQ; Wed, 23 Apr 2025 11:15:37 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1u7VFP-00000009evV-3sOW for linux-nvme@lists.infradead.org; Wed, 23 Apr 2025 08:14:25 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 2461E44CDB; Wed, 23 Apr 2025 08:14:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5478C4CEEA; Wed, 23 Apr 2025 08:14:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745396063; bh=uAyqUew9YbHt6BqNCxqg/xSEI2KBPG3SEWmdj1qq/2k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ab3QxyUR3AxcfYmJpPAjvqg3xVX9ODRdOtP4JjD+gjlPYMs4aWD0v0tpV2XnmQsxA 0KPdYd02efI42gcXRsCWx2Kb+9opFXjZbR1HUjikV3RjBmXKsyXdtf26St3GlCyMQn RmKtt/ojtBWdmNBJhgfOTqas5pc7ykEsC9TyqD6y0FRFzYkspoz7H9ae32vwWiNMuc QpvU00rqe1EOIbCMApFKFU0rNMpJ+97Z50JxAWaJj8Wiq1a4ef6edn2PCfl4Lzy46m RahxcFpKB5UGFzsNjUTKHQJ+S4Tfs0dgHIK0Sm96MOEKDhw2afVZOUZkuuu7gIWge0 aW83SgnSvz2Dw== From: Leon Romanovsky To: Marek Szyprowski , Jens Axboe , Christoph Hellwig , Keith Busch Cc: Jake Edge , Jonathan Corbet , Jason Gunthorpe , Zhu Yanjun , Robin Murphy , Joerg Roedel , Will Deacon , Sagi Grimberg , Bjorn Helgaas , Logan Gunthorpe , Yishai Hadas , Shameer Kolothum , Kevin Tian , Alex Williamson , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Andrew Morton , 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, Niklas Schnelle , Chuck Lever , Luis Chamberlain , Matthew Wilcox , Dan Williams , Kanchan Joshi , Chaitanya Kulkarni , Leon Romanovsky Subject: [PATCH v9 08/24] dma-mapping: add a dma_need_unmap helper Date: Wed, 23 Apr 2025 11:12:59 +0300 Message-ID: X-Mailer: git-send-email 2.49.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250423_011424_054272_55133C2A X-CRM114-Status: GOOD ( 14.58 ) X-Mailman-Approved-At: Wed, 23 Apr 2025 03:40:46 -0700 X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org 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 Tested-by: Jens Axboe 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); -- 2.49.0