From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 07/19] dma-iommu: fix and refactor iommu_dma_get_sgtable Date: Mon, 14 Jan 2019 10:41:47 +0100 Message-ID: <20190114094159.27326-8-hch@lst.de> References: <20190114094159.27326-1-hch@lst.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190114094159.27326-1-hch@lst.de> Sender: linux-kernel-owner@vger.kernel.org To: Robin Murphy 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 The current iommu_dma_get_sgtable code does not properly handle memory from the page allocator that hasn't been remapped, which can happen in the rare case of allocations for a coherent device that aren't allowed to block. Fix this by replacing iommu_dma_get_sgtable with a slightly tweaked copy of dma_common_get_sgtable with special handling for the remapped array of pages allocated from __iommu_dma_alloc. Signed-off-by: Christoph Hellwig --- drivers/iommu/dma-iommu.c | 49 +++++++++++++++++++-------------------- 1 file changed, 24 insertions(+), 25 deletions(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 26f479d49103..8f3dc6ab3da1 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -620,6 +620,18 @@ static int iommu_dma_mmap_remap(void *cpu_addr, size_t size, return ret; } +static int iommu_dma_get_sgtable_remap(struct sg_table *sgt, void *cpu_addr, + size_t size) +{ + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + struct vm_struct *area = find_vm_area(cpu_addr); + + if (WARN_ON(!area || !area->pages)) + return -ENXIO; + return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size, + GFP_KERNEL); +} + static void iommu_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction dir) { @@ -1080,37 +1092,24 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, user_count << PAGE_SHIFT, vma->vm_page_prot); } -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 vm_struct *area = find_vm_area(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); - } + struct page *page; + int ret; - if (WARN_ON(!area || !area->pages)) - return -ENXIO; + if (is_vmalloc_addr(cpu_addr)) { + if (!(attrs & DMA_ATTR_FORCE_CONTIGUOUS)) + return iommu_dma_get_sgtable_remap(sgt, cpu_addr, size); + page = vmalloc_to_page(cpu_addr); + } else + page = virt_to_page(cpu_addr); - return sg_alloc_table_from_pages(sgt, area->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 = { -- 2.20.1