dma-direct: don't retry allocation for no-op GFP_DMA

When an allocation with lower dma_coherent mask fails, dma_direct_alloc()
retries the allocation with GFP_DMA.  But, this is useless for
architectures that hav no ZONE_DMA.

Fix it by adding the check of CONFIG_ZONE_DMA before retrying the
allocation.

Fixes: 95f183916d4b ("dma-direct: retry allocations using GFP_DMA for small masks")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index c0bba30fef0ac1f8bda32af158b5596fcc14ce09..bbfb229aa0675ed73d438ce2700e674891758310 100644 (file)
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -84,7 +84,8 @@ again:
                __free_pages(page, page_order);
                page = NULL;
 
-               if (dev->coherent_dma_mask < DMA_BIT_MASK(32) &&
+               if (IS_ENABLED(CONFIG_ZONE_DMA) &&
+                   dev->coherent_dma_mask < DMA_BIT_MASK(32) &&
                    !(gfp & GFP_DMA)) {
                        gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
                        goto again;