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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 7BB3DC19F3F for ; Thu, 29 Jul 2021 20:16:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66BC460FE7 for ; Thu, 29 Jul 2021 20:16:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233111AbhG2UQH (ORCPT ); Thu, 29 Jul 2021 16:16:07 -0400 Received: from ale.deltatee.com ([204.191.154.188]:59120 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232559AbhG2UP6 (ORCPT ); Thu, 29 Jul 2021 16:15:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:MIME-Version:References:In-Reply-To: Message-Id:Date:Cc:To:From:content-disposition; bh=H+Im41O7i4qTWPUG8nmhAyL/mhQK6e1NSTli9mmAHj8=; b=R6YCg3TpOKaR1Y4CrcmnaTxy33 cL39gW2wQHn3/jHstlvcLcncw+hBAJ2Zh5HCUW9PHfwfvZc2ti77IDa5KY292K9h2fyHGv+1o1nkx kCrpnxFz1QXzehsvCE9BUIUIrHkD/7jmjkose2mCIJLyPUUEBJiAKDVdYYpLzmZBidXWFlg/zaVjP QaUN5OTrX2Sf1Jh292wu6GIXkZAauRIgBeTwCUNfxb8KlqGNp/Yj1IMMJgtWiOuSjZIcbEkiF+fjW YzW6uo4UYB0y6AtSw7fBxyl27xiJeTyzglR6RPGWURru8kUj8ommDOQS9qsec1F9eEDGg97TbTWpT UUhk46xg==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1m9CRW-0008VL-N8; Thu, 29 Jul 2021 14:15:47 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.92) (envelope-from ) id 1m9CRT-0001TS-Ke; Thu, 29 Jul 2021 14:15:43 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, iommu@lists.linux-foundation.org, linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org Cc: Christoph Hellwig , Marek Szyprowski , Robin Murphy , Stephen Bates , Martin Oliveira , Logan Gunthorpe Date: Thu, 29 Jul 2021 14:15:19 -0600 Message-Id: <20210729201539.5602-2-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210729201539.5602-1-logang@deltatee.com> References: <20210729201539.5602-1-logang@deltatee.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, sbates@raithlin.com, martin.oliveira@eideticom.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v3 01/21] dma-mapping: Allow map_sg() ops to return negative error codes X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Allow dma_map_sgtable() to pass errors from the map_sg() ops. This will be required for returning appropriate error codes when mapping P2PDMA memory. Introduce __dma_map_sg_attrs() which will return the raw error code from the map_sg operation (whether it be negative or zero). Then add a dma_map_sg_attrs() wrapper to convert any negative errors to zero to satisfy the existing calling convention. dma_map_sgtable() defines three error codes that .map_sg implementations are allowed to return: -EINVAL, -ENOMEM and -EIO. The latter of which is a generic return for cases that are passing DMA_MAPPING_ERROR through. dma_map_sgtable() will convert a zero error return for old map_sg() ops into a -EIO return and return any negative errors as reported. This allows map_sg implementations to start returning multiple negative error codes. Legacy map_sg implementations can continue to return zero until they are all converted. Signed-off-by: Logan Gunthorpe --- include/linux/dma-map-ops.h | 5 ++- include/linux/dma-mapping.h | 35 ++++------------ kernel/dma/mapping.c | 84 +++++++++++++++++++++++++++++++++---- 3 files changed, 86 insertions(+), 38 deletions(-) diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 0d53a96a3d64..2f842498c448 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -41,8 +41,9 @@ struct dma_map_ops { size_t size, enum dma_data_direction dir, unsigned long attrs); /* - * map_sg returns 0 on error and a value > 0 on success. - * It should never return a value < 0. + * map_sg should return a negative error code on error. See + * dma_map_sgtable() for a list of appropriate error codes + * and their meanings. */ int (*map_sg)(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 183e7103a66d..daa1e360f0ee 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -110,6 +110,8 @@ int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); +int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs); dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size, enum dma_data_direction dir, unsigned long attrs); void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, @@ -174,6 +176,11 @@ static inline void dma_unmap_sg_attrs(struct device *dev, unsigned long attrs) { } +static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs) +{ + return -EOPNOTSUPP; +} static inline dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size, enum dma_data_direction dir, unsigned long attrs) @@ -343,34 +350,6 @@ static inline void dma_sync_single_range_for_device(struct device *dev, return dma_sync_single_for_device(dev, addr + offset, size, dir); } -/** - * dma_map_sgtable - Map the given buffer for DMA - * @dev: The device for which to perform the DMA operation - * @sgt: The sg_table object describing the buffer - * @dir: DMA direction - * @attrs: Optional DMA attributes for the map operation - * - * Maps a buffer described by a scatterlist stored in the given sg_table - * object for the @dir DMA operation by the @dev device. After success the - * ownership for the buffer is transferred to the DMA domain. One has to - * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the - * ownership of the buffer back to the CPU domain before touching the - * buffer by the CPU. - * - * Returns 0 on success or -EINVAL on error during mapping the buffer. - */ -static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt, - enum dma_data_direction dir, unsigned long attrs) -{ - int nents; - - nents = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); - if (nents <= 0) - return -EINVAL; - sgt->nents = nents; - return 0; -} - /** * dma_unmap_sgtable - Unmap the given buffer for DMA * @dev: The device for which to perform the DMA operation diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 2b06a809d0b9..9f0bb56eb9aa 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -177,12 +177,8 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, } EXPORT_SYMBOL(dma_unmap_page_attrs); -/* - * dma_maps_sg_attrs returns 0 on error and > 0 on success. - * It should never return a value < 0. - */ -int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, - enum dma_data_direction dir, unsigned long attrs) +static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); int ents; @@ -197,13 +193,85 @@ int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, ents = dma_direct_map_sg(dev, sg, nents, dir, attrs); else ents = ops->map_sg(dev, sg, nents, dir, attrs); - BUG_ON(ents < 0); - debug_dma_map_sg(dev, sg, nents, ents, dir); + + if (ents > 0) + debug_dma_map_sg(dev, sg, nents, ents, dir); + else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM && + ents != -EIO && ents != 0)) + return -EIO; return ents; } + +/** + * dma_map_sg_attrs - Map the given buffer for DMA + * @dev: The device for which to perform the DMA operation + * @sg: The sg_table object describing the buffer + * @dir: DMA direction + * @attrs: Optional DMA attributes for the map operation + * + * Maps a buffer described by a scatterlist passed in the sg argument with + * nents segments for the @dir DMA operation by the @dev device. + * + * Returns the number of mapped entries (which can be less than nents) + * on success. Zero is returned for any error. + * + * dma_unmap_sg_attrs() should be used to unmap the buffer with the + * original sg and original nents (not the value returned by this funciton). + */ +int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, unsigned long attrs) +{ + int ret; + + ret = __dma_map_sg_attrs(dev, sg, nents, dir, attrs); + if (ret < 0) + ret = 0; + + return ret; +} EXPORT_SYMBOL(dma_map_sg_attrs); +/** + * dma_map_sgtable - Map the given buffer for DMA + * @dev: The device for which to perform the DMA operation + * @sgt: The sg_table object describing the buffer + * @dir: DMA direction + * @attrs: Optional DMA attributes for the map operation + * + * Maps a buffer described by a scatterlist stored in the given sg_table + * object for the @dir DMA operation by the @dev device. After success, the + * ownership for the buffer is transferred to the DMA domain. One has to + * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the + * ownership of the buffer back to the CPU domain before touching the + * buffer by the CPU. + * + * Returns 0 on success or a negative error code on error. The following + * error codes are supported with the given meaning: + * + * -EINVAL - An invalid argument, unaligned access or other error + * in usage. Will not succeed if retried. + * -ENOMEM - Insufficient resources (like memory or IOVA space) to + * complete the mapping. Should succeed if retried later. + * -EIO - Legacy error code with an unknown meaning. eg. this is + * returned if a lower level call returned DMA_MAPPING_ERROR. + */ +int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs) +{ + int nents; + + nents = __dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); + if (nents == 0) + return -EIO; + else if (nents < 0) + return nents; + + sgt->nents = nents; + return 0; +} +EXPORT_SYMBOL_GPL(dma_map_sgtable); + void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs) -- 2.20.1