From bcf4b9c4c2ee0f00d9e273b19419416a20cce9a4 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Mon, 20 May 2019 09:29:36 +0200 Subject: iommu/dma: Refactor iommu_dma_free The freeing logic was made particularly horrible by part of it being opaque to the arch wrapper, which led to a lot of convoluted repetition to ensure each path did everything in the right order. Now that it's all private, we can pick apart and consolidate the logically-distinct steps of freeing the IOMMU mapping, the underlying pages, and the CPU remap (if necessary) into something much more manageable. Signed-off-by: Robin Murphy [various cosmetic changes to the code flow] Signed-off-by: Christoph Hellwig Signed-off-by: Joerg Roedel --- drivers/iommu/dma-iommu.c | 73 +++++++++++++++++++++-------------------------- 1 file changed, 33 insertions(+), 40 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 5e0c8450fa0b..a288b3d366ae 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -935,6 +935,39 @@ static void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, __iommu_dma_unmap(dev, handle, size); } +static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, unsigned long attrs) +{ + size_t alloc_size = PAGE_ALIGN(size); + int count = alloc_size >> PAGE_SHIFT; + struct page *page = NULL, **pages = NULL; + + __iommu_dma_unmap(dev, handle, size); + + /* Non-coherent atomic allocation? Easy */ + if (dma_free_from_pool(cpu_addr, alloc_size)) + return; + + if (is_vmalloc_addr(cpu_addr)) { + /* + * If it the address is remapped, then it's either non-coherent + * or highmem CMA, or an iommu_dma_alloc_remap() construction. + */ + pages = __iommu_dma_get_pages(cpu_addr); + if (!pages) + page = vmalloc_to_page(cpu_addr); + dma_common_free_remap(cpu_addr, alloc_size, VM_USERMAP); + } else { + /* Lowmem means a coherent atomic or CMA allocation */ + page = virt_to_page(cpu_addr); + } + + if (pages) + __iommu_dma_free_pages(pages, count); + if (page && !dma_release_from_contiguous(dev, page, count)) + __free_pages(page, get_order(alloc_size)); +} + static void *iommu_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, unsigned long attrs) { @@ -1004,46 +1037,6 @@ static void *iommu_dma_alloc(struct device *dev, size_t size, return addr; } -static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr, - dma_addr_t handle, unsigned long attrs) -{ - size_t iosize = size; - - size = PAGE_ALIGN(size); - /* - * @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_remap(), for all - * non-atomic allocations. - * - A non-cacheable alias from the atomic pool, for atomic - * allocations by non-coherent devices. - * - A normal lowmem address, for atomic allocations by - * coherent devices. - * Hence how dodgy the below logic looks... - */ - if (dma_in_atomic_pool(cpu_addr, size)) { - __iommu_dma_unmap(dev, handle, iosize); - dma_free_from_pool(cpu_addr, size); - } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { - struct page *page = vmalloc_to_page(cpu_addr); - - __iommu_dma_unmap(dev, handle, iosize); - 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 page **pages = __iommu_dma_get_pages(cpu_addr); - - if (!pages) - return; - __iommu_dma_unmap(dev, handle, iosize); - __iommu_dma_free_pages(pages, size >> PAGE_SHIFT); - dma_common_free_remap(cpu_addr, size, VM_USERMAP); - } else { - __iommu_dma_unmap(dev, handle, iosize); - __free_pages(virt_to_page(cpu_addr), get_order(size)); - } -} - static int __iommu_dma_mmap_pfn(struct vm_area_struct *vma, unsigned long pfn, size_t size) { -- cgit v1.2.3-55-g7522