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=-14.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 CFACAC433E2 for ; Thu, 10 Sep 2020 21:37:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CF42208E4 for ; Thu, 10 Sep 2020 21:37:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726926AbgIJVhQ (ORCPT ); Thu, 10 Sep 2020 17:37:16 -0400 Received: from foss.arm.com ([217.140.110.172]:36190 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728442AbgIJNeW (ORCPT ); Thu, 10 Sep 2020 09:34:22 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6D844106F; Thu, 10 Sep 2020 06:34:21 -0700 (PDT) Received: from [10.57.40.122] (unknown [10.57.40.122]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 69B3C3F66E; Thu, 10 Sep 2020 06:34:19 -0700 (PDT) Subject: Re: [PATCH 11/12] dma-mapping: move dma_common_{mmap,get_sgtable} out of mapping.c To: Christoph Hellwig , Tony Luck , Fenghua Yu , Thomas Bogendoerfer , iommu@lists.linux-foundation.org Cc: Tomasz Figa , Joerg Roedel , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org References: <20200908164758.3177341-1-hch@lst.de> <20200908164758.3177341-12-hch@lst.de> From: Robin Murphy Message-ID: <88bae26e-d5f4-7a00-a88a-b69194d519a4@arm.com> Date: Thu, 10 Sep 2020 14:34:18 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200908164758.3177341-12-hch@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-09-08 17:47, Christoph Hellwig wrote: > Add a new file that contains helpera for misc DMA ops, which is only The Latin plural of the singular "helperum", I guess? :P > built when CONFIG_DMA_OPS is set. Reviewed-by: Robin Murphy > Signed-off-by: Christoph Hellwig > --- > kernel/dma/Makefile | 1 + > kernel/dma/mapping.c | 47 +----------------------------------- > kernel/dma/ops_helpers.c | 51 ++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 53 insertions(+), 46 deletions(-) > create mode 100644 kernel/dma/ops_helpers.c > > diff --git a/kernel/dma/Makefile b/kernel/dma/Makefile > index 32c7c1942bbd6c..dc755ab68aabf9 100644 > --- a/kernel/dma/Makefile > +++ b/kernel/dma/Makefile > @@ -1,6 +1,7 @@ > # SPDX-License-Identifier: GPL-2.0 > > obj-$(CONFIG_HAS_DMA) += mapping.o direct.o > +obj-$(CONFIG_DMA_OPS) += ops_helpers.o > obj-$(CONFIG_DMA_OPS) += dummy.o > obj-$(CONFIG_DMA_CMA) += contiguous.o > obj-$(CONFIG_DMA_DECLARE_COHERENT) += coherent.o > diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c > index 0d129421e75fc8..848c95c27d79ff 100644 > --- a/kernel/dma/mapping.c > +++ b/kernel/dma/mapping.c > @@ -8,7 +8,7 @@ > #include /* for max_pfn */ > #include > #include > -#include > +#include > #include > #include > #include > @@ -295,22 +295,6 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, > } > EXPORT_SYMBOL(dma_sync_sg_for_device); > > -/* > - * Create scatter-list for the already allocated DMA buffer. > - */ > -int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, > - void *cpu_addr, dma_addr_t dma_addr, size_t size, > - unsigned long attrs) > -{ > - struct page *page = virt_to_page(cpu_addr); > - int ret; > - > - ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > - if (!ret) > - sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > - return ret; > -} > - > /* > * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems > * that the intention is to allow exporting memory allocated via the > @@ -358,35 +342,6 @@ pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs) > } > #endif /* CONFIG_MMU */ > > -/* > - * Create userspace mapping for the DMA-coherent memory. > - */ > -int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, > - void *cpu_addr, dma_addr_t dma_addr, size_t size, > - unsigned long attrs) > -{ > -#ifdef CONFIG_MMU > - unsigned long user_count = vma_pages(vma); > - unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; > - unsigned long off = vma->vm_pgoff; > - int ret = -ENXIO; > - > - vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs); > - > - if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) > - return ret; > - > - if (off >= count || user_count > count - off) > - return -ENXIO; > - > - return remap_pfn_range(vma, vma->vm_start, > - page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, > - user_count << PAGE_SHIFT, vma->vm_page_prot); > -#else > - return -ENXIO; > -#endif /* CONFIG_MMU */ > -} > - > /** > * dma_can_mmap - check if a given device supports dma_mmap_* > * @dev: device to check > diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c > new file mode 100644 > index 00000000000000..e443c69be4299f > --- /dev/null > +++ b/kernel/dma/ops_helpers.c > @@ -0,0 +1,51 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Helpers for DMA ops implementations. These generally rely on the fact that > + * the allocated memory contains normal pages in the direct kernel mapping. > + */ > +#include > + > +/* > + * Create scatter-list for the already allocated DMA buffer. > + */ > +int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, > + void *cpu_addr, dma_addr_t dma_addr, size_t size, > + unsigned long attrs) > +{ > + struct page *page = virt_to_page(cpu_addr); > + int ret; > + > + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > + if (!ret) > + sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > + return ret; > +} > + > +/* > + * Create userspace mapping for the DMA-coherent memory. > + */ > +int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, > + void *cpu_addr, dma_addr_t dma_addr, size_t size, > + unsigned long attrs) > +{ > +#ifdef CONFIG_MMU > + unsigned long user_count = vma_pages(vma); > + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; > + unsigned long off = vma->vm_pgoff; > + int ret = -ENXIO; > + > + vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs); > + > + if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) > + return ret; > + > + if (off >= count || user_count > count - off) > + return -ENXIO; > + > + return remap_pfn_range(vma, vma->vm_start, > + page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, > + user_count << PAGE_SHIFT, vma->vm_page_prot); > +#else > + return -ENXIO; > +#endif /* CONFIG_MMU */ > +} >