diff options
Diffstat (limited to 'arch/arm64/mm/dma-mapping.c')
| -rw-r--r-- | arch/arm64/mm/dma-mapping.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index a96ec0181818..1e9dac8684ca 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -33,6 +33,7 @@ #include <asm/cacheflush.h> static int swiotlb __ro_after_init; +DEFINE_STATIC_KEY_FALSE(swiotlb_noncoherent_bounce); static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot, bool coherent) @@ -504,6 +505,14 @@ static int __init arm64_dma_init(void) max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT)) swiotlb = 1; + if (WARN_TAINT(ARCH_DMA_MINALIGN < cache_line_size(), + TAINT_CPU_OUT_OF_SPEC, + "ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (%d < %d)", + ARCH_DMA_MINALIGN, cache_line_size())) { + swiotlb = 1; + static_branch_enable(&swiotlb_noncoherent_bounce); + } + return atomic_pool_init(); } arch_initcall(arm64_dma_init); @@ -882,6 +891,14 @@ static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, const struct iommu_ops *iommu, bool coherent) { + /* + * Enable swiotlb for buffer bouncing if ARCH_DMA_MINALIGN < CWG. + * dma_capable() forces the actual bounce if the device is + * non-coherent. + */ + if (static_branch_unlikely(&swiotlb_noncoherent_bounce) && !coherent) + iommu = NULL; + if (!dev->dma_ops) dev->dma_ops = &arm64_swiotlb_dma_ops; |