From 34ab03160eda51839be6dd5a939680963266707c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 3 Jun 2019 12:48:57 +0200 Subject: arm-nommu: remove the partial DMA_ATTR_NON_CONSISTENT support The arm-nommu DMA code supports DMA_ATTR_NON_CONSISTENT allocations, but does not provide a cache_sync operation. This means any user of it will never be able to actually transfer cache ownership and thus cause coherency bugs. Signed-off-by: Christoph Hellwig Reviewed-by: Vladimir Murzin --- arch/arm/mm/dma-mapping-nommu.c | 24 +++--------------------- 1 file changed, 3 insertions(+), 21 deletions(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c index f304b10e23a4..bc003df45546 100644 --- a/arch/arm/mm/dma-mapping-nommu.c +++ b/arch/arm/mm/dma-mapping-nommu.c @@ -39,18 +39,7 @@ static void *arm_nommu_dma_alloc(struct device *dev, size_t size, unsigned long attrs) { - void *ret; - - /* - * Try generic allocator first if we are advertised that - * consistency is not required. - */ - - if (attrs & DMA_ATTR_NON_CONSISTENT) - return dma_direct_alloc_pages(dev, size, dma_handle, gfp, - attrs); - - ret = dma_alloc_from_global_coherent(size, dma_handle); + void *ret = dma_alloc_from_global_coherent(size, dma_handle); /* * dma_alloc_from_global_coherent() may fail because: @@ -70,16 +59,9 @@ static void arm_nommu_dma_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs) { - if (attrs & DMA_ATTR_NON_CONSISTENT) { - dma_direct_free_pages(dev, size, cpu_addr, dma_addr, attrs); - } else { - int ret = dma_release_from_global_coherent(get_order(size), - cpu_addr); - - WARN_ON_ONCE(ret == 0); - } + int ret = dma_release_from_global_coherent(get_order(size), cpu_addr); - return; + WARN_ON_ONCE(ret == 0); } static int arm_nommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, -- cgit v1.2.3