Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753883AbcCRMMa (ORCPT ); Fri, 18 Mar 2016 08:12:30 -0400 Received: from foss.arm.com ([217.140.101.70]:53912 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752393AbcCRMMU (ORCPT ); Fri, 18 Mar 2016 08:12:20 -0400 Subject: Re: [PATCH 2/3] swiotlb: prefix dma_to_phys and phys_to_dma functions To: Sinan Kaya , linux-arm-kernel@lists.infradead.org, timur@codeaurora.org, cov@codeaurora.org, nwatters@codeaurora.org References: <1458252137-24497-1-git-send-email-okaya@codeaurora.org> <1458252137-24497-2-git-send-email-okaya@codeaurora.org> Cc: linux-mips@linux-mips.org, linux-ia64@vger.kernel.org, linux-xtensa@linux-xtensa.org, Catalin Marinas , Will Deacon , Max Filippov , Chris Metcalf , Paul Mackerras , "H. Peter Anvin" , Huacai Chen , Guan Xuetao , Marek Szyprowski , Jisheng Zhang , Florian Fainelli , Russell King , Aaro Koskinen , Michael Ellerman , x86@kernel.org, Ingo Molnar , Benjamin Herrenschmidt , Guenter Roeck , Fenghua Yu , Denys Vlasenko , Arnd Bergmann , Konrad Rzeszutek Wilk , Akinobu Mita , Bjorn Helgaas , Thomas Gleixner , Valentin Rothberg , Chris Zankel , Tony Luck , linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Dean Nelson , linux-kernel@vger.kernel.org, Ralf Baechle , "Suthikulpanit, Suravee" , Joe Perches , Andrew Morton From: Robin Murphy Message-ID: <56EBF09A.1060503@arm.com> Date: Fri, 18 Mar 2016 12:12:10 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1458252137-24497-2-git-send-email-okaya@codeaurora.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7692 Lines: 207 On 17/03/16 22:02, Sinan Kaya wrote: > Prefixing dma_to_phys and phys_to_dma API with swiotlb so that > they are no longer part of the DMA API. These APIs do not exist > on all architectures and breaks compatibility. > > In preparation for the clean up, also make the ARCH implementation > known by defining swiotlb_phys_do_dma and swiotlb_dma_to_phys. > > Signed-off-by: Sinan Kaya > --- > arch/arm/include/asm/dma-mapping.h | 8 ++- > arch/arm64/include/asm/dma-mapping.h | 9 ++- > arch/arm64/mm/dma-mapping.c | 75 ++++++++++++++-------- [...] > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index a6e757c..ada00c3 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -107,7 +107,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size, > if (!page) > return NULL; > > - *dma_handle = phys_to_dma(dev, page_to_phys(page)); > + *dma_handle = swiotlb_phys_to_dma(dev, page_to_phys(page)); > addr = page_address(page); > memset(addr, 0, size); > return addr; > @@ -121,7 +121,7 @@ static void __dma_free_coherent(struct device *dev, size_t size, > struct dma_attrs *attrs) > { > bool freed; > - phys_addr_t paddr = dma_to_phys(dev, dma_handle); > + phys_addr_t paddr = swiotlb_dma_to_phys(dev, dma_handle); > > if (dev == NULL) { > WARN_ONCE(1, "Use an actual device structure for DMA allocation\n"); > @@ -151,7 +151,8 @@ static void *__dma_alloc(struct device *dev, size_t size, > void *addr = __alloc_from_pool(size, &page, flags); > > if (addr) > - *dma_handle = phys_to_dma(dev, page_to_phys(page)); > + *dma_handle = swiotlb_phys_to_dma(dev, > + page_to_phys(page)); > > return addr; > } > @@ -187,7 +188,7 @@ static void __dma_free(struct device *dev, size_t size, > void *vaddr, dma_addr_t dma_handle, > struct dma_attrs *attrs) > { > - void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle)); > + void *swiotlb_addr = phys_to_virt(swiotlb_dma_to_phys(dev, dma_handle)); > > size = PAGE_ALIGN(size); > > @@ -208,7 +209,8 @@ static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page, > > dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs); > if (!is_device_dma_coherent(dev)) > - __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); > + __dma_map_area(phys_to_virt(swiotlb_dma_to_phys(dev, dev_addr)), > + size, dir); > > return dev_addr; > } > @@ -218,8 +220,11 @@ static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr, > size_t size, enum dma_data_direction dir, > struct dma_attrs *attrs) > { > - if (!is_device_dma_coherent(dev)) > - __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); > + if (!is_device_dma_coherent(dev)) { > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dev_addr); > + > + __dma_unmap_area(phys_to_virt(phys), size, dir); > + } > swiotlb_unmap_page(dev, dev_addr, size, dir, attrs); > } > > @@ -232,9 +237,12 @@ static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl, > > ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs); > if (!is_device_dma_coherent(dev)) > - for_each_sg(sgl, sg, ret, i) > - __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), > - sg->length, dir); > + for_each_sg(sgl, sg, ret, i) { > + dma_addr_t dma = sg->dma_address; > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dma); > + > + __dma_map_area(phys_to_virt(phys), sg->length, dir); > + } > > return ret; > } > @@ -248,9 +256,12 @@ static void __swiotlb_unmap_sg_attrs(struct device *dev, > int i; > > if (!is_device_dma_coherent(dev)) > - for_each_sg(sgl, sg, nelems, i) > - __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), > - sg->length, dir); > + for_each_sg(sgl, sg, nelems, i) { > + dma_addr_t dma = sg->dma_address; > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dma); > + > + __dma_unmap_area(phys_to_virt(phys), sg->length, dir); > + } > swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs); > } > > @@ -258,8 +269,11 @@ static void __swiotlb_sync_single_for_cpu(struct device *dev, > dma_addr_t dev_addr, size_t size, > enum dma_data_direction dir) > { > - if (!is_device_dma_coherent(dev)) > - __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); > + if (!is_device_dma_coherent(dev)) { > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dev_addr); > + > + __dma_unmap_area(phys_to_virt(phys), size, dir); > + } > swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir); > } > > @@ -269,7 +283,8 @@ static void __swiotlb_sync_single_for_device(struct device *dev, > { > swiotlb_sync_single_for_device(dev, dev_addr, size, dir); > if (!is_device_dma_coherent(dev)) > - __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); > + __dma_map_area(phys_to_virt(swiotlb_dma_to_phys(dev, dev_addr)), > + size, dir); > } > > static void __swiotlb_sync_sg_for_cpu(struct device *dev, > @@ -280,9 +295,12 @@ static void __swiotlb_sync_sg_for_cpu(struct device *dev, > int i; > > if (!is_device_dma_coherent(dev)) > - for_each_sg(sgl, sg, nelems, i) > - __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), > - sg->length, dir); > + for_each_sg(sgl, sg, nelems, i) { > + dma_addr_t dma = sg->dma_address; > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dma); > + > + __dma_unmap_area(phys_to_virt(phys), sg->length, dir); > + } > swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir); > } > > @@ -295,9 +313,12 @@ static void __swiotlb_sync_sg_for_device(struct device *dev, > > swiotlb_sync_sg_for_device(dev, sgl, nelems, dir); > if (!is_device_dma_coherent(dev)) > - for_each_sg(sgl, sg, nelems, i) > - __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), > - sg->length, dir); > + for_each_sg(sgl, sg, nelems, i) { > + dma_addr_t dma = sg->dma_address; > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dma); > + > + __dma_map_area(phys_to_virt(phys), sg->length, dir); > + } > } > > static int __swiotlb_mmap(struct device *dev, > @@ -309,7 +330,7 @@ static int __swiotlb_mmap(struct device *dev, > unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> > PAGE_SHIFT; > unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; > - unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT; > + unsigned long pfn = swiotlb_dma_to_phys(dev, dma_addr) >> PAGE_SHIFT; > unsigned long off = vma->vm_pgoff; > > vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot, > @@ -334,9 +355,11 @@ static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt, > { > int ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > > - if (!ret) > - sg_set_page(sgt->sgl, phys_to_page(dma_to_phys(dev, handle)), > - PAGE_ALIGN(size), 0); > + if (!ret) { > + phys_addr_t phys = swiotlb_dma_to_phys(dev, handle); > + > + sg_set_page(sgt->sgl, phys_to_page(phys), PAGE_ALIGN(size), 0); > + } > > return ret; > } Since we know for sure that swiotlb_to_phys is a no-op on arm64, it might be cleaner to simply not reference it at all. I suppose we could have some private local wrappers, e.g.: #define swiotlb_to_virt(addr) phys_to_virt((phys_addr_t)(addr)) to keep the intent of the code clear (and just in case anyone ever builds a system mad enough to warrant switching out that definition, but I'd hope that never happens). Otherwise, looks good - thanks for doing this! Robin.