From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH 21/26] iommu/dma: Refactor iommu_dma_get_sgtable Date: Mon, 29 Apr 2019 15:08:58 +0100 Message-ID: <10b0710c-b2b4-7647-6846-71d9df4bd038@arm.com> References: <20190422175942.18788-1-hch@lst.de> <20190422175942.18788-22-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190422175942.18788-22-hch@lst.de> Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org To: Christoph Hellwig Cc: Joerg Roedel , Catalin Marinas , Will Deacon , Tom Lendacky , iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: iommu@lists.linux-foundation.org On 22/04/2019 18:59, Christoph Hellwig wrote: > Inline __iommu_dma_get_sgtable_page into the main function, and use the > fact that __iommu_dma_get_pages return NULL for remapped contigous > allocations to simplify the code flow a bit. Yeah, even I was a bit dubious about the readability of "if (page)... else if (pages)..." that my attempt ended up with, so I don't really have anything to complain about here. Reviewed-by: Robin Murphy > Signed-off-by: Christoph Hellwig > --- > drivers/iommu/dma-iommu.c | 45 +++++++++++++++------------------------ > 1 file changed, 17 insertions(+), 28 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index acdfe866cb29..138b85e675c8 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -1070,42 +1070,31 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, > return __iommu_dma_mmap(pages, size, vma); > } > > -static int __iommu_dma_get_sgtable_page(struct sg_table *sgt, struct page *page, > - size_t size) > -{ > - int ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > - > - if (!ret) > - sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > - return ret; > -} > - > static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs) > { > - unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; > - struct page **pages; > + struct page *page; > + int ret; > > - if (!is_vmalloc_addr(cpu_addr)) { > - struct page *page = virt_to_page(cpu_addr); > - return __iommu_dma_get_sgtable_page(sgt, page, size); > - } > + if (is_vmalloc_addr(cpu_addr)) { > + struct page **pages = __iommu_dma_get_pages(cpu_addr); > > - if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { > - /* > - * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped, > - * hence in the vmalloc space. > - */ > - struct page *page = vmalloc_to_page(cpu_addr); > - return __iommu_dma_get_sgtable_page(sgt, page, size); > + if (pages) { > + return sg_alloc_table_from_pages(sgt, pages, > + PAGE_ALIGN(size) >> PAGE_SHIFT, > + 0, size, GFP_KERNEL); > + } > + > + page = vmalloc_to_page(cpu_addr); > + } else { > + page = virt_to_page(cpu_addr); > } > > - pages = __iommu_dma_get_pages(cpu_addr); > - if (WARN_ON_ONCE(!pages)) > - return -ENXIO; > - return sg_alloc_table_from_pages(sgt, pages, count, 0, size, > - GFP_KERNEL); > + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > + if (!ret) > + sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > + return ret; > } > > static const struct dma_map_ops iommu_dma_ops = { > 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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 C61DBC43219 for ; Mon, 29 Apr 2019 14:11:04 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A1CCC2084B for ; Mon, 29 Apr 2019 14:11:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A1CCC2084B Authentication-Results: mail.kernel.org; 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Mon, 29 Apr 2019 07:08:59 -0700 (PDT) Subject: Re: [PATCH 21/26] iommu/dma: Refactor iommu_dma_get_sgtable To: Christoph Hellwig References: <20190422175942.18788-1-hch@lst.de> <20190422175942.18788-22-hch@lst.de> From: Robin Murphy Message-ID: <10b0710c-b2b4-7647-6846-71d9df4bd038@arm.com> Date: Mon, 29 Apr 2019 15:08:58 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190422175942.18788-22-hch@lst.de> Content-Language: en-GB Cc: Tom Lendacky , Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="UTF-8"; format="flowed" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Message-ID: <20190429140858.1Al_nS9AgHc6DXHgRgJwYK8SNNl9hQohMzeAauz3_1A@z> On 22/04/2019 18:59, Christoph Hellwig wrote: > Inline __iommu_dma_get_sgtable_page into the main function, and use the > fact that __iommu_dma_get_pages return NULL for remapped contigous > allocations to simplify the code flow a bit. Yeah, even I was a bit dubious about the readability of "if (page)... else if (pages)..." that my attempt ended up with, so I don't really have anything to complain about here. Reviewed-by: Robin Murphy > Signed-off-by: Christoph Hellwig > --- > drivers/iommu/dma-iommu.c | 45 +++++++++++++++------------------------ > 1 file changed, 17 insertions(+), 28 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index acdfe866cb29..138b85e675c8 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -1070,42 +1070,31 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, > return __iommu_dma_mmap(pages, size, vma); > } > > -static int __iommu_dma_get_sgtable_page(struct sg_table *sgt, struct page *page, > - size_t size) > -{ > - int ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > - > - if (!ret) > - sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > - return ret; > -} > - > static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs) > { > - unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; > - struct page **pages; > + struct page *page; > + int ret; > > - if (!is_vmalloc_addr(cpu_addr)) { > - struct page *page = virt_to_page(cpu_addr); > - return __iommu_dma_get_sgtable_page(sgt, page, size); > - } > + if (is_vmalloc_addr(cpu_addr)) { > + struct page **pages = __iommu_dma_get_pages(cpu_addr); > > - if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { > - /* > - * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped, > - * hence in the vmalloc space. > - */ > - struct page *page = vmalloc_to_page(cpu_addr); > - return __iommu_dma_get_sgtable_page(sgt, page, size); > + if (pages) { > + return sg_alloc_table_from_pages(sgt, pages, > + PAGE_ALIGN(size) >> PAGE_SHIFT, > + 0, size, GFP_KERNEL); > + } > + > + page = vmalloc_to_page(cpu_addr); > + } else { > + page = virt_to_page(cpu_addr); > } > > - pages = __iommu_dma_get_pages(cpu_addr); > - if (WARN_ON_ONCE(!pages)) > - return -ENXIO; > - return sg_alloc_table_from_pages(sgt, pages, count, 0, size, > - GFP_KERNEL); > + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > + if (!ret) > + sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > + return ret; > } > > static const struct dma_map_ops iommu_dma_ops = { > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu