Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932718AbcCHJWi (ORCPT ); Tue, 8 Mar 2016 04:22:38 -0500 Received: from mail-pa0-f48.google.com ([209.85.220.48]:33888 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932656AbcCHJWa (ORCPT ); Tue, 8 Mar 2016 04:22:30 -0500 From: Stephen Boyd To: linux-kernel@vger.kernel.org Cc: linux-arm@lists.infradead.org, Greg Kroah-Hartman , Mimi Zohar , Andrew Morton , Mark Brown , Laura Abbott , Robin Murphy , Laura Abbott , Arnd Bergmann , Marek Szyprowski , Catalin Marinas , Will Deacon Subject: [PATCH 1/4] ARM64: dma: Add support for NO_KERNEL_MAPPING attribute Date: Tue, 8 Mar 2016 16:22:16 +0700 Message-Id: <1457428939-26659-2-git-send-email-stephen.boyd@linaro.org> X-Mailer: git-send-email 2.7.0.25.gfc10eb5 In-Reply-To: <1457428939-26659-1-git-send-email-stephen.boyd@linaro.org> References: <1457428939-26659-1-git-send-email-stephen.boyd@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4034 Lines: 119 Both the IOMMU and non-IOMMU allocations don't respect the NO_KERNEL_MAPPING attribute, therefore drivers can't save virtual address space and time spent mapping large buffers that are intended only for userspace. Plumb this attribute into the code for both types of DMA ops. Cc: Robin Murphy Cc: Laura Abbott Cc: Arnd Bergmann Cc: Marek Szyprowski Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Stephen Boyd --- arch/arm64/mm/dma-mapping.c | 39 ++++++++++++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 9 deletions(-) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 331c4ca6205c..06a593653f23 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -169,6 +169,9 @@ static void *__dma_alloc(struct device *dev, size_t size, /* create a coherent mapping */ page = virt_to_page(ptr); + if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) + return page; + coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP, prot, NULL); if (!coherent_ptr) @@ -194,7 +197,8 @@ static void __dma_free(struct device *dev, size_t size, if (!is_device_dma_coherent(dev)) { if (__free_from_pool(vaddr, size)) return; - vunmap(vaddr); + if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) + vunmap(vaddr); } __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs); } @@ -567,6 +571,9 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, if (!pages) return NULL; + if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) + return pages; + addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot, __builtin_return_address(0)); if (!addr) @@ -624,18 +631,32 @@ static void __iommu_free_attrs(struct device *dev, size_t size, void *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); + if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) + dma_common_free_remap(cpu_addr, size, VM_USERMAP); } else { iommu_dma_unmap_page(dev, handle, iosize, 0, NULL); __free_pages(virt_to_page(cpu_addr), get_order(size)); } } +static struct page **__iommu_get_pages(void *cpu_addr, struct dma_attrs *attrs) +{ + struct vm_struct *area; + + if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) + return cpu_addr; + + area = find_vm_area(cpu_addr); + if (area) + return area->pages; + return NULL; +} + static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs) { - struct vm_struct *area; + struct page **pages; int ret; vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot, @@ -644,11 +665,11 @@ static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) return ret; - area = find_vm_area(cpu_addr); - if (WARN_ON(!area || !area->pages)) + pages = __iommu_get_pages(cpu_addr, attrs); + if (WARN_ON(!pages)) return -ENXIO; - return iommu_dma_mmap(area->pages, size, vma); + return iommu_dma_mmap(pages, size, vma); } static int __iommu_get_sgtable(struct device *dev, struct sg_table *sgt, @@ -656,12 +677,12 @@ static int __iommu_get_sgtable(struct device *dev, struct sg_table *sgt, size_t size, struct dma_attrs *attrs) { unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; - struct vm_struct *area = find_vm_area(cpu_addr); + struct page **pages = __iommu_get_pages(cpu_addr, attrs); - if (WARN_ON(!area || !area->pages)) + if (WARN_ON(!pages)) return -ENXIO; - return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size, + return sg_alloc_table_from_pages(sgt, pages, count, 0, size, GFP_KERNEL); } -- 2.7.0.25.gfc10eb5