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 93A75C3ABB6 for ; Mon, 5 May 2025 07:13:48 +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=0/3N3K7XZccfvrp8qdj4h6IoKH4QoumzCs4XS69VK+U=; b=oQhvnN7HKytXauk+kJKzLe708N bs/r8kzPvBTg3CudpIAeBwCVCEh6mdxJN32xHOgFePmMRn6w3a1cofJerhxHz+RYYseqRffUq1oVN A3ESOLXs7VHlayQKkquKSa7NHb+YqIhMcGRM+9U22Ct0kffilC/ZvJzrnU5sgXf7PBfjPQk6hLix0 GrhO/w8uRTjW/pVC3F8dgfgB/IaZs9A9e8nraeMNML7caS16/DMcbGLkptshNTR7WsAcLQfTMtbbV 88p/x+BHuCVsiUY/m3O9np/DkpQmQ+q/G26CD3UthIs4BxHjl1BMB/QXHC471B4P3bd8gU6xSfp9M hyKVrh2w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uBq1L-00000006c3s-0qTx; Mon, 05 May 2025 07:13:47 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uBpqR-00000006ZsA-0OzC for linux-nvme@lists.infradead.org; Mon, 05 May 2025 07:02:31 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 5A81661129; Mon, 5 May 2025 07:01:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 824E5C4CEE4; Mon, 5 May 2025 07:02:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746428550; bh=zDzlqykv86nTBfYEytc8wm5wkFShzSQKAsrmEhNbBwU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qqtM0p4gWP9l89f4xe03WY9yh8S81jdJOy9cNmMjR+Mi9fNCGSmR3SKl9rQnAZ6HK ifaZF9J3ukpYGHCWk8qbzAYHobwBSK6ZPE9c8zYYX98JeidbQ7xvgllEiqhKw0HOpM dzM7fO8tAGhd7WaF/P3BocqEX/LTe/YP3sRfSN9JLTsTIeDn2vlwVi/rBP3xpLyLA0 Hfk7nonUdMRXWPDCOVNaRXYIZ29to9Zuf/kf5xo6D/n5im+HZTPVbVJ8h8oioMZnvc WaFLtd5J2lafRtA3roO1fRn3KaNxX7b0rzVH9A9CgLTev2i9azW/8Bo4QESW8C3baq DP06qo478a2iw== From: Leon Romanovsky To: Cc: Christoph Hellwig , Jens Axboe , Keith Busch , 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 v11 8/9] dma-mapping: add a dma_need_unmap helper Date: Mon, 5 May 2025 10:01:45 +0300 Message-ID: <11ca5400460fa195692bd413387b06ac484e03b4.1746424934.git.leon@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Mon, 05 May 2025 00:13:41 -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 Reviewed-by: Luis Chamberlain 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