diff options
Diffstat (limited to 'arch/arm64/mm/dma-mapping.c')
| -rw-r--r-- | arch/arm64/mm/dma-mapping.c | 17 |
1 files changed, 1 insertions, 16 deletions
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 5240f6acad64..3cb101e8cb29 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -36,22 +36,7 @@ void arch_dma_prep_coherent(struct page *page, size_t size) { unsigned long start = (unsigned long)page_address(page); - /* - * The architecture only requires a clean to the PoC here in order to - * meet the requirements of the DMA API. However, some vendors (i.e. - * Qualcomm) abuse the DMA API for transferring buffers from the - * non-secure to the secure world, resetting the system if a non-secure - * access shows up after the buffer has been transferred: - * - * https://lore.kernel.org/r/20221114110329.68413-1-manivannan.sadhasivam@linaro.org - * - * Using clean+invalidate appears to make this issue less likely, but - * the drivers themselves still need fixing as the CPU could issue a - * speculative read from the buffer via the linear mapping irrespective - * of the cache maintenance we use. Once the drivers are fixed, we can - * relax this to a clean operation. - */ - dcache_clean_inval_poc(start, start + size); + dcache_clean_poc(start, start + size); } #ifdef CONFIG_IOMMU_DMA |