From patchwork Wed Jan 30 16:40:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joerg Roedel X-Patchwork-Id: 10789003 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1F79213BF for ; Wed, 30 Jan 2019 16:40:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0F33D30042 for ; Wed, 30 Jan 2019 16:40:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 027C1300A0; Wed, 30 Jan 2019 16:40:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 62385300B2 for ; Wed, 30 Jan 2019 16:40:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732243AbfA3QkM (ORCPT ); Wed, 30 Jan 2019 11:40:12 -0500 Received: from 8bytes.org ([81.169.241.247]:36044 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727225AbfA3QkL (ORCPT ); Wed, 30 Jan 2019 11:40:11 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id 31BFD6C4; Wed, 30 Jan 2019 17:40:09 +0100 (CET) From: Joerg Roedel To: "Michael S . Tsirkin" , Jason Wang , Konrad Rzeszutek Wilk , Christoph Hellwig Cc: Jens Axboe , virtualization@lists.linux-foundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jfehlig@suse.com, jon.grimm@amd.com, brijesh.singh@amd.com, joro@8bytes.org, jroedel@suse.de, Thomas.Lendacky@amd.com Subject: [PATCH 3/5] dma: Introduce dma_max_mapping_size() Date: Wed, 30 Jan 2019 17:40:05 +0100 Message-Id: <20190130164007.26497-4-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190130164007.26497-1-joro@8bytes.org> References: <20190130164007.26497-1-joro@8bytes.org> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Joerg Roedel The function returns the maximum size that can be mapped using DMA-API functions. The patch also adds the implementation for direct DMA and a new dma_map_ops pointer so that other implementations can expose their limit. Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Christoph Hellwig Signed-off-by: Joerg Roedel --- Documentation/DMA-API.txt | 8 ++++++++ include/linux/dma-mapping.h | 16 ++++++++++++++++ kernel/dma/direct.c | 12 ++++++++++++ 3 files changed, 36 insertions(+) diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index e133ccd60228..acfe3d0f78d1 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -195,6 +195,14 @@ Requesting the required mask does not alter the current mask. If you wish to take advantage of it, you should issue a dma_set_mask() call to set the mask to the value returned. +:: + + size_t + dma_direct_max_mapping_size(struct device *dev); + +Returns the maximum size of a mapping for the device. The size parameter +of the mapping functions like dma_map_single(), dma_map_page() and +others should not be larger than the returned value. Part Id - Streaming DMA mappings -------------------------------- diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index f6ded992c183..a3ca8a71a704 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -130,6 +130,7 @@ struct dma_map_ops { enum dma_data_direction direction); int (*dma_supported)(struct device *dev, u64 mask); u64 (*get_required_mask)(struct device *dev); + size_t (*max_mapping_size)(struct device *dev); }; #define DMA_MAPPING_ERROR (~(dma_addr_t)0) @@ -257,6 +258,8 @@ static inline void dma_direct_sync_sg_for_cpu(struct device *dev, } #endif +size_t dma_direct_max_mapping_size(struct device *dev); + #ifdef CONFIG_HAS_DMA #include @@ -440,6 +443,19 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) return 0; } +static inline size_t dma_max_mapping_size(struct device *dev) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + size_t size = SIZE_MAX; + + if (dma_is_direct(ops)) + size = dma_direct_max_mapping_size(dev); + else if (ops && ops->max_mapping_size) + size = ops->max_mapping_size(dev); + + return size; +} + void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs); void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 355d16acee6d..81ca8170b928 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -380,3 +380,15 @@ int dma_direct_supported(struct device *dev, u64 mask) */ return mask >= __phys_to_dma(dev, min_mask); } + +size_t dma_direct_max_mapping_size(struct device *dev) +{ + size_t size = SIZE_MAX; + + /* If SWIOTLB is active, use its maximum mapping size */ + if (is_swiotlb_active()) + size = swiotlb_max_mapping_size(dev); + + return size; +} +EXPORT_SYMBOL(dma_direct_max_mapping_size);