From 42998ef08aba01643d99f65718903b4414a8922f Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 21 Apr 2022 12:36:57 +0100 Subject: [PATCH] ARM/dma-mapping: drop .dma_supported for IOMMU ops When an IOMMU is present, we trust that it should be capable of remapping any physical memory, and since the device masks represent the input (virtual) addresses to the IOMMU it makes no sense to validate them against physical PFNs anyway. Signed-off-by: Robin Murphy Signed-off-by: Christoph Hellwig Tested-by: Marc Zyngier --- arch/arm/mm/dma-mapping.c | 23 ----------------------- 1 file changed, 23 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index ceb56928d01e..4055f2dc2859 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -104,25 +104,6 @@ static struct arm_dma_buffer *arm_dma_buffer_find(void *virt) * */ -#ifdef CONFIG_ARM_DMA_USE_IOMMU -/* - * Return whether the given device DMA address mask can be supported - * properly. For example, if your device can only drive the low 24-bits - * during bus mastering, then you would pass 0x00ffffff as the mask - * to this function. - */ -static int arm_dma_supported(struct device *dev, u64 mask) -{ - unsigned long max_dma_pfn = min(max_pfn - 1, arm_dma_pfn_limit); - - /* - * Translate the device's DMA mask to a PFN limit. This - * PFN number includes the page which we can DMA to. - */ - return PHYS_PFN(dma_to_phys(dev, mask)) >= max_dma_pfn; -} -#endif - static void __dma_clear_buffer(struct page *page, size_t size, int coherent_flag) { /* @@ -1681,8 +1662,6 @@ static const struct dma_map_ops iommu_ops = { .map_resource = arm_iommu_map_resource, .unmap_resource = arm_iommu_unmap_resource, - - .dma_supported = arm_dma_supported, }; static const struct dma_map_ops iommu_coherent_ops = { @@ -1699,8 +1678,6 @@ static const struct dma_map_ops iommu_coherent_ops = { .map_resource = arm_iommu_map_resource, .unmap_resource = arm_iommu_unmap_resource, - - .dma_supported = arm_dma_supported, }; /**