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 39823C02185 for ; Fri, 17 Jan 2025 11:18:08 +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=Irhj2QQiTBNUb9SSTzF7SWHwxYmY67f2A+u8b3gQU54=; b=xAKnB4ql6UTDqesQbfbfP3+TSU 0gd2y4DFDHHBNxpqqtiykMtGnAGJ8KCCSeCK62SNlDOholucHe9dfAHttR6iKzhxABcJ64G+9F39m ai0BP9DyZY+NiXkmfrToR9XKExyOpcGroDmTfIqwWfEmOOyDilMoTmuxL0H+kE2zpvaC6SB2ViTnh Hm/ZPoGiakeDeBfFCUDoDSHZULex+WYvknIJKjm9Gb4okJyMBWi7hvlx31PBrTsJANX6WK9CQmSHp wHMro4PKG4i1D14f+62qj6MrpYhETGiUs7fv/rSghN9BjoZ2VJDizU28VJdcJTq8vgrouEs6/1xO9 2weAZnhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tYkMI-000000007Fm-0joT; Fri, 17 Jan 2025 11:17:50 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tYjDu-0000000HXUd-1QkJ for linux-nvme@bombadil.infradead.org; Fri, 17 Jan 2025 10:05:06 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:MIME-Version :References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=Irhj2QQiTBNUb9SSTzF7SWHwxYmY67f2A+u8b3gQU54=; b=KEp+lr0C5kW/nPSE9SlRZEJNHf EdLmSs2TIFcNV3E+xqUBMfniAiYSbGhXTsHWmIrCWxQjCbm2zM4pyDZSLUA9WL1udMs6tvBpzeu0D PfKSUiqKX1xi+SFAQ1w/im2ZzVw3b3EOcGnX7FOh7A1sa15g1VaD17qaUSB8+JOYZWqxw9CAE4aWt zWfmG9HlWMNlBSD8WejF8FjE9iragXi460Fwqjumghce2FlL/HYCxwH7FtGrMtl+tCC4h4c/9+Cth BlHNBc04dLtBb18ogGkfzc0zLP8lZXFP4HhONxCigYOyovfwzrFcuoRvMZq9rRVgwg8Y8XdAsKIdA fHhbbBSA==; Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by desiato.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tYjDY-0000000BOpl-1AnU for linux-nvme@lists.infradead.org; Fri, 17 Jan 2025 10:05:05 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id CF07FA42B32; Fri, 17 Jan 2025 10:02:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8323C4CEDD; Fri, 17 Jan 2025 10:04:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737108279; bh=FJYQ7qR9hcBLpRhiPHcPvV9HvqBheLEfsFGqvBAMLaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vExohzXD6Ujd7i5ylWAXIQ8r+KiHahR4ugS8NzRN12jXXWg6XpFDS0Az2kDJdGS3b r2P83zACaoMN4Wm74N2ASzU3RY5SHuQvegOGleRrgJR0ewKZNF1R7rYaprTdiqfZta qHAONZp/pjWD0Exsf2wMAG5W74kZ9llv+fixzaMpWuVhexQbaRl57Q96SppjOh8KaZ UB7ck8uR8pWleUg587r5ORtXxR7k4/8yK6Oa7z3askZexI38iaJksqiskbye1+z2jM yfRbYsVQg1Ux+DbZ9S99dgY9nJvxXEfXBrI8xyOVSpm8JiF79noUc1A75KueNPzS9U QWTZ4Ku7NpBiA== 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?q?J=C3=A9r=C3=B4me=20Glisse?= , "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 v6 08/17] dma-mapping: add a dma_need_unmap helper Date: Fri, 17 Jan 2025 12:03:39 +0200 Message-ID: <9458f681274f4f0e5dd3bf3959e0b8a1ac9a4e7b.1737106761.git.leon@kernel.org> X-Mailer: git-send-email 2.47.1 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-20250117_100457_977276_49FC3A9C X-CRM114-Status: GOOD ( 13.44 ) 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 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); -- 2.47.1