dma-mapping: add a dma_alloc_need_uncached helper

Check if we need to allocate uncached memory for a device given the
allocation flags.  Switch over the uncached segment check to this helper
to deal with architectures that do not support the dma_cache_sync
operation and thus should not returned cacheable memory for
DMA_ATTR_NON_CONSISTENT allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index b67f0aa08aa3..c2893713bf80 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -160,7 +160,7 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
         memset(ret, 0, size);
 
         if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
-            !dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_NON_CONSISTENT)) {
+            dma_alloc_need_uncached(dev, attrs)) {
                 arch_dma_prep_coherent(page, size);
                 ret = uncached_kernel_address(ret);
         }
@@ -182,7 +182,7 @@ void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
                 set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order);
 
         if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
-            !dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_NON_CONSISTENT))
+            dma_alloc_need_uncached(dev, attrs))
                 cpu_addr = cached_kernel_address(cpu_addr);
         __dma_direct_free_pages(dev, size, virt_to_page(cpu_addr));
 }