From patchwork Mon Mar 1 08:52:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 71780 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1lGeMu-00EEPO-Mm; Mon, 01 Mar 2021 08:57:33 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233578AbhCAI4x (ORCPT + 1 other); Mon, 1 Mar 2021 03:56:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233582AbhCAIys (ORCPT ); Mon, 1 Mar 2021 03:54:48 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34C05C06174A; Mon, 1 Mar 2021 00:54:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=J1KHVQd7KIKA4eutBclaxDE2iy2Glo4eu+2ejZioyaQ=; b=vzWa2E0TktPPujc2OKk4KpSe7L f5AGhX4tGFsXwRelNHe541ktMZg0gUWgjM8CeUmJvj9s+UTWLHgxgHTcB2OLCCxUC6isRrXEXEJ+U WQMAqccxtJfH4SQznEiSmemCnFgV9E0+ezk3No2VovvhdDcypCIXXoyX4BZXzJ+VhAsB7EID283pp g1R6UPp+u5g6oPKRxLC0Rh1fio7D79UF5jNdpB/Cb7VX+x3ueOk+8NFXUF2rGX1hfWKeIuRbn5fAi dKPXDXwuk+oOVTdQMWzCeKmG73Z4NgjjVUJbz3Eq37oNqm4XLpp8HUxvzrH2r4X9W67B940aJ2P8u rgbjfMug==; Received: from [2001:4bb8:19b:e4b7:cdf9:733f:4874:8eb4] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lGeIN-00FVG1-Ro; Mon, 01 Mar 2021 08:52:58 +0000 From: Christoph Hellwig To: Mauro Carvalho Chehab , Marek Szyprowski , Tomasz Figa , Ricardo Ribalda , Sergey Senozhatsky , Laurent Pinchart , iommu@lists.linux-foundation.org Cc: Robin Murphy , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: [PATCH 1/6] dma-mapping: add a dma_mmap_pages helper Date: Mon, 1 Mar 2021 09:52:31 +0100 Message-Id: <20210301085236.947011-2-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210301085236.947011-1-hch@lst.de> References: <20210301085236.947011-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -2.4 (--) X-LSpam-Report: No, score=-2.4 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1 autolearn=ham autolearn_force=no Add a helper to map memory allocated using dma_alloc_pages into a user address space, similar to the dma_alloc_attrs function for coherent allocations. Signed-off-by: Christoph Hellwig Reviewed-by: Tomasz Figa Tested-by: Ricardo Ribalda --- Documentation/core-api/dma-api.rst | 10 ++++++++++ include/linux/dma-mapping.h | 2 ++ kernel/dma/mapping.c | 13 +++++++++++++ 3 files changed, 25 insertions(+) diff --git a/Documentation/core-api/dma-api.rst b/Documentation/core-api/dma-api.rst index e6d23f117308df..157a474ae54416 100644 --- a/Documentation/core-api/dma-api.rst +++ b/Documentation/core-api/dma-api.rst @@ -563,6 +563,16 @@ Free a region of memory previously allocated using dma_alloc_pages(). dev, size, dma_handle and dir must all be the same as those passed into dma_alloc_pages(). page must be the pointer returned by dma_alloc_pages(). +:: + + int + dma_mmap_pages(struct device *dev, struct vm_area_struct *vma, + size_t size, struct page *page) + +Map an allocation returned from dma_alloc_pages() into a user address space. +dev and size must be the same as those passed into dma_alloc_pages(). +page must be the pointer returned by dma_alloc_pages(). + :: void * diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 2a984cb4d1e037..2b8dce756e1fa1 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -263,6 +263,8 @@ struct page *dma_alloc_pages(struct device *dev, size_t size, dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp); void dma_free_pages(struct device *dev, size_t size, struct page *page, dma_addr_t dma_handle, enum dma_data_direction dir); +int dma_mmap_pages(struct device *dev, struct vm_area_struct *vma, + size_t size, struct page *page); static inline void *dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp) diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b6a63367993328..9ce86c77651c6f 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -517,6 +517,19 @@ void dma_free_pages(struct device *dev, size_t size, struct page *page, } EXPORT_SYMBOL_GPL(dma_free_pages); +int dma_mmap_pages(struct device *dev, struct vm_area_struct *vma, + size_t size, struct page *page) +{ + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; + + if (vma->vm_pgoff >= count || vma_pages(vma) > count - vma->vm_pgoff) + return -ENXIO; + return remap_pfn_range(vma, vma->vm_start, + page_to_pfn(page) + vma->vm_pgoff, + vma_pages(vma) << PAGE_SHIFT, vma->vm_page_prot); +} +EXPORT_SYMBOL_GPL(dma_mmap_pages); + int dma_supported(struct device *dev, u64 mask) { const struct dma_map_ops *ops = get_dma_ops(dev);