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 autolearn=ham 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 5816DC10F0E for ; Tue, 9 Apr 2019 16:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2216A2084F for ; Tue, 9 Apr 2019 16:39:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726655AbfDIQjD (ORCPT ); Tue, 9 Apr 2019 12:39:03 -0400 Received: from foss.arm.com ([217.140.101.70]:41050 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726538AbfDIQjC (ORCPT ); Tue, 9 Apr 2019 12:39:02 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8BF6C15BE; Tue, 9 Apr 2019 09:39:02 -0700 (PDT) Received: from [10.1.196.75] (e110467-lin.cambridge.arm.com [10.1.196.75]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2AAF43F68F; Tue, 9 Apr 2019 09:39:01 -0700 (PDT) Subject: Re: [PATCH 11/21] dma-iommu: refactor page array remap helpers 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 References: <20190327080448.5500-1-hch@lst.de> <20190327080448.5500-12-hch@lst.de> From: Robin Murphy Message-ID: <9fe28aa4-3b7c-ee98-3f73-f10271f06c3a@arm.com> Date: Tue, 9 Apr 2019 17:38:59 +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: <20190327080448.5500-12-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 27/03/2019 08:04, Christoph Hellwig wrote: > Move the call to dma_common_pages_remap / dma_common_free_remap into > __iommu_dma_alloc / __iommu_dma_free and rename those functions to > better describe what they do. This keeps the functionality that > allocates and remaps a non-contigous array of pages nicely abstracted > out from the calling code. > > Signed-off-by: Christoph Hellwig > --- > drivers/iommu/dma-iommu.c | 75 +++++++++++++++++++-------------------- > 1 file changed, 36 insertions(+), 39 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 4d46beeea5b7..2013c650718a 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -524,51 +524,57 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev, > } > > /** > - * iommu_dma_free - Free a buffer allocated by __iommu_dma_alloc() > + * iommu_dma_free_remap - Free a buffer allocated by iommu_dma_alloc_remap Unmap and free a buffer allocated by iommu_dma_alloc_remap() > * @dev: Device which owns this buffer > - * @pages: Array of buffer pages as returned by __iommu_dma_alloc() > * @size: Size of buffer in bytes > + * @cpu_address: Virtual address of the buffer > * @handle: DMA address of buffer @dma_handle > * > * Frees both the pages associated with the buffer, and the array > * describing them and removes the CPU mapping. > */ > -static void __iommu_dma_free(struct device *dev, struct page **pages, > - size_t size, dma_addr_t *handle) > +static void iommu_dma_free_remap(struct device *dev, size_t size, > + void *cpu_addr, dma_addr_t dma_handle) > { > - __iommu_dma_unmap(iommu_get_dma_domain(dev), *handle, size); > - __iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT); > - *handle = DMA_MAPPING_ERROR; > + struct vm_struct *area = find_vm_area(cpu_addr); > + > + if (WARN_ON(!area || !area->pages)) > + return; > + __iommu_dma_unmap(iommu_get_dma_domain(dev), dma_handle, size); > + __iommu_dma_free_pages(area->pages, PAGE_ALIGN(size) >> PAGE_SHIFT); > + dma_common_free_remap(cpu_addr, PAGE_ALIGN(size), VM_USERMAP); > } > > /** > - * __iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space > + * iommu_dma_alloc_remap - Allocate and map a buffer contiguous in IOVA space I'm not sure of a succinct way to update that one :( Other than kerneldoc nits, though, Reviewed-by: Robin Murphy > * @dev: Device to allocate memory for. Must be a real device > * attached to an iommu_dma_domain > * @size: Size of buffer in bytes > + * @dma_handle: Out argument for allocated DMA handle > * @gfp: Allocation flags > * @attrs: DMA attributes for this allocation > - * @prot: IOMMU mapping flags > - * @handle: Out argument for allocated DMA handle > * > * If @size is less than PAGE_SIZE, then a full CPU page will be allocated, > * but an IOMMU which supports smaller pages might not map the whole thing. > * > - * Return: Array of struct page pointers describing the buffer, > - * or NULL on failure. > + * Return: Mapped virtual address, or NULL on failure. > */ > -static struct page **__iommu_dma_alloc(struct device *dev, size_t size, > - gfp_t gfp, unsigned long attrs, int prot, dma_addr_t *handle) > +static void *iommu_dma_alloc_remap(struct device *dev, size_t size, > + dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) > { > struct iommu_domain *domain = iommu_get_dma_domain(dev); > struct iommu_dma_cookie *cookie = domain->iova_cookie; > struct iova_domain *iovad = &cookie->iovad; > + bool coherent = dev_is_dma_coherent(dev); > + int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs); > + pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs); > + unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap; > struct page **pages; > struct sg_table sgt; > dma_addr_t iova; > - unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap; > + void *vaddr; > > - *handle = DMA_MAPPING_ERROR; > + *dma_handle = DMA_MAPPING_ERROR; > > min_size = alloc_sizes & -alloc_sizes; > if (min_size < PAGE_SIZE) { > @@ -594,7 +600,7 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size, > if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL)) > goto out_free_iova; > > - if (!(prot & IOMMU_CACHE)) { > + if (!(ioprot & IOMMU_CACHE)) { > struct scatterlist *sg; > int i; > > @@ -602,14 +608,21 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size, > arch_dma_prep_coherent(sg_page(sg), sg->length); > } > > - if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, prot) > + if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, ioprot) > < size) > goto out_free_sg; > > - *handle = iova; > + vaddr = dma_common_pages_remap(pages, size, VM_USERMAP, prot, > + __builtin_return_address(0)); > + if (!vaddr) > + goto out_unmap; > + > + *dma_handle = iova; > sg_free_table(&sgt); > - return pages; > + return vaddr; > > +out_unmap: > + __iommu_dma_unmap(domain, iova, size); > out_free_sg: > sg_free_table(&sgt); > out_free_iova: > @@ -1013,18 +1026,7 @@ static void *iommu_dma_alloc(struct device *dev, size_t size, > size >> PAGE_SHIFT); > } > } else { > - pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs); > - struct page **pages; > - > - pages = __iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot, > - handle); > - if (!pages) > - return NULL; > - > - addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot, > - __builtin_return_address(0)); > - if (!addr) > - __iommu_dma_free(dev, pages, iosize, handle); > + addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs); > } > return addr; > } > @@ -1038,7 +1040,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr, > /* > * @cpu_addr will be one of 4 things depending on how it was allocated: > * - A remapped array of pages for contiguous allocations. > - * - A remapped array of pages from __iommu_dma_alloc(), for all > + * - A remapped array of pages from iommu_dma_alloc_remap(), for all > * non-atomic allocations. > * - A non-cacheable alias from the atomic pool, for atomic > * allocations by non-coherent devices. > @@ -1056,12 +1058,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr, > dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT); > dma_common_free_remap(cpu_addr, size, VM_USERMAP); > } else if (is_vmalloc_addr(cpu_addr)){ > - struct vm_struct *area = find_vm_area(cpu_addr); > - > - if (WARN_ON(!area || !area->pages)) > - return; > - __iommu_dma_free(dev, area->pages, iosize, &handle); > - dma_common_free_remap(cpu_addr, size, VM_USERMAP); > + iommu_dma_free_remap(dev, iosize, cpu_addr, handle); > } else { > __iommu_dma_unmap_page(dev, handle, iosize, 0, 0); > __free_pages(virt_to_page(cpu_addr), get_order(size)); >