From patchwork Wed Aug 28 12:35:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yoshihiro Shimoda X-Patchwork-Id: 11118899 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0C3D516B1 for ; Wed, 28 Aug 2019 12:37:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9FB422DA7 for ; Wed, 28 Aug 2019 12:37:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726438AbfH1Mh3 (ORCPT ); Wed, 28 Aug 2019 08:37:29 -0400 Received: from relmlor2.renesas.com ([210.160.252.172]:37304 "EHLO relmlie6.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726339AbfH1Mh2 (ORCPT ); Wed, 28 Aug 2019 08:37:28 -0400 X-IronPort-AV: E=Sophos;i="5.64,441,1559487600"; d="scan'208";a="24934329" Received: from unknown (HELO relmlir5.idc.renesas.com) ([10.200.68.151]) by relmlie6.idc.renesas.com with ESMTP; 28 Aug 2019 21:37:25 +0900 Received: from localhost.localdomain (unknown [10.166.17.210]) by relmlir5.idc.renesas.com (Postfix) with ESMTP id B2C57400516A; Wed, 28 Aug 2019 21:37:25 +0900 (JST) From: Yoshihiro Shimoda To: ulf.hansson@linaro.org, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, joro@8bytes.org, axboe@kernel.dk Cc: wsa+renesas@sang-engineering.com, linux-mmc@vger.kernel.org, iommu@lists.linux-foundation.org, linux-block@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda Subject: [PATCH v10 1/4] dma: Introduce dma_get_merge_boundary() Date: Wed, 28 Aug 2019 21:35:40 +0900 Message-Id: <1566995743-5614-2-git-send-email-yoshihiro.shimoda.uh@renesas.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1566995743-5614-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> References: <1566995743-5614-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org This patch adds a new DMA API "dma_get_merge_boundary". This function returns the DMA merge boundary if the DMA layer can merge the segments. This patch also adds the implementation for a new dma_map_ops pointer. Signed-off-by: Yoshihiro Shimoda Reviewed-by: Christoph Hellwig Reviewed-by: Simon Horman --- Documentation/DMA-API.txt | 8 ++++++++ include/linux/dma-mapping.h | 6 ++++++ kernel/dma/mapping.c | 11 +++++++++++ 3 files changed, 25 insertions(+) diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index e47c63b..9c4dd3d 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -204,6 +204,14 @@ 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. +:: + + unsigned long + dma_get_merge_boundary(struct device *dev); + +Returns the DMA merge boundary. If the device cannot merge any the DMA address +segments, the function returns 0. + Part Id - Streaming DMA mappings -------------------------------- diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 14702e2..7072b78 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -131,6 +131,7 @@ struct dma_map_ops { int (*dma_supported)(struct device *dev, u64 mask); u64 (*get_required_mask)(struct device *dev); size_t (*max_mapping_size)(struct device *dev); + unsigned long (*get_merge_boundary)(struct device *dev); }; #define DMA_MAPPING_ERROR (~(dma_addr_t)0) @@ -462,6 +463,7 @@ int dma_set_mask(struct device *dev, u64 mask); int dma_set_coherent_mask(struct device *dev, u64 mask); u64 dma_get_required_mask(struct device *dev); size_t dma_max_mapping_size(struct device *dev); +unsigned long dma_get_merge_boundary(struct device *dev); #else /* CONFIG_HAS_DMA */ static inline dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, size_t offset, size_t size, @@ -567,6 +569,10 @@ static inline size_t dma_max_mapping_size(struct device *dev) { return 0; } +static inline unsigned long dma_get_merge_boundary(struct device *dev) +{ + return 0; +} #endif /* CONFIG_HAS_DMA */ static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr, diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b0038ca..b3077b5 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -405,3 +405,14 @@ size_t dma_max_mapping_size(struct device *dev) return size; } EXPORT_SYMBOL_GPL(dma_max_mapping_size); + +unsigned long dma_get_merge_boundary(struct device *dev) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + + if (!ops || !ops->get_merge_boundary) + return 0; /* can't merge */ + + return ops->get_merge_boundary(dev); +} +EXPORT_SYMBOL_GPL(dma_get_merge_boundary);