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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79036C43387 for ; Tue, 15 Jan 2019 13:23:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53E8220657 for ; Tue, 15 Jan 2019 13:23:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729668AbfAONXC (ORCPT ); Tue, 15 Jan 2019 08:23:02 -0500 Received: from 8bytes.org ([81.169.241.247]:57774 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729307AbfAONXC (ORCPT ); Tue, 15 Jan 2019 08:23:02 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id 60D68433; Tue, 15 Jan 2019 14:23:00 +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 Subject: [PATCH 2/3] dma: Introduce dma_max_mapping_size() Date: Tue, 15 Jan 2019 14:22:56 +0100 Message-Id: <20190115132257.6426-3-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190115132257.6426-1-joro@8bytes.org> References: <20190115132257.6426-1-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Joerg Roedel --- include/linux/dma-mapping.h | 16 ++++++++++++++++ kernel/dma/direct.c | 10 ++++++++++ 2 files changed, 26 insertions(+) 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..84917e1003c4 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -380,3 +380,13 @@ 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) +{ + /* + * Return the minimum of the direct DMA limit and the SWIOTLB limit. + * Since direct DMA has no limit, it is fine to just return the SWIOTLB + * limit. + */ + return swiotlb_max_mapping_size(dev); +} -- 2.17.1