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 7F13CE7718C for ; Tue, 17 Dec 2024 13:02:07 +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=I8zeuz1LusMcrZY1ZH3SbXwbZVAiaCQQJNl/hX6DDvQ=; b=ZDA170pMZqmaYElDtMaYRaK26+ ITWi3dubeIkXYPpCGa5qnD61hfU5bj0KH2J+B5YV3ofafN63iE6viNse1NrgnpCCwDhUrRDEzyOPL R49Bihlu9xYDUBZceVd0xS67WAifFSedgsxSsFsE490scgSZRMPG++GN3IrBy3QYsOLZcEKgsARLR uCy/5tLYrY29b3i8+O98UNYvkiQ6s+JiYFaguBGTQDW3lhED1JI8xh6wvozKM/ZtG09so8+OxNSJZ 0W7f4Be+eVpxsSJR29QBSqIVKjhPH0tNGH8IiYwUCU0p/vhE85VRuo+plWjEMC6odq8APZGNK1yDN +QT2Mkjw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tNXDB-0000000DSiY-3U2O; Tue, 17 Dec 2024 13:02:05 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tNXCc-0000000DSMV-0Xco for linux-nvme@lists.infradead.org; Tue, 17 Dec 2024 13:01:31 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 6F5845C62C4; Tue, 17 Dec 2024 13:00:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E3CFC4CED4; Tue, 17 Dec 2024 13:01:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1734440489; bh=iIU3nAodcPqgXhM415qJ6UO7wN8Xjlyg5zHcBf3DQZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HEKE/+zX+ZdFZ/bWCF8cQSMXArY/rreeS3qzRw8Eeu6EzOGw/Z1JrKiOfPOyVSkFH kHZlx+qqB7dSpSCgCpOCMOtZc+Fo8v+6UYjKoFb2Xd9zDNsuFoI0OOuBsJxZPl7pJh dNSTnpKCfVe82F/lCx8zqFy3TaxV2gFUGzc7/qFSsbzSmOi5OQoKMuHthehZMzeMam eLzSmHxPiLYfsTmC8Jw/a52JDN/ZH/+lyrzoi8FkhpRTZjxnQa6rv9eItSzpWooiYV CxiBLRT9PR8d8JkpFs8QBkshTvp9Yc+wF1IOA4vnuA3uNmm5kbPutlclWHDhQx3klo D9T+xxGicipwg== From: Leon Romanovsky To: Jens Axboe , Jason Gunthorpe , Robin Murphy , Joerg Roedel , Will Deacon , Christoph Hellwig , Sagi Grimberg Cc: 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 v5 08/17] dma-mapping: add a dma_need_unmap helper Date: Tue, 17 Dec 2024 15:00:26 +0200 Message-ID: X-Mailer: git-send-email 2.47.0 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-20241217_050130_249393_6563024D X-CRM114-Status: GOOD ( 14.45 ) 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 f4d717e17bde..bda090beb9b1 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -407,6 +407,7 @@ 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) { @@ -432,6 +433,10 @@ 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); -- 2.47.0