MIPS: fix DMA contiguous allocation

Recent changes to how GFP_ATOMIC is defined seems to have broken the
condition to use mips_alloc_from_contiguous() in
mips_dma_alloc_coherent().

I couldn't bottom out the exact change but I think it's this commit
d0164adc89f6 ("mm, page_alloc: distinguish between being unable to
sleep, unwilling to sleep and avoiding waking kswapd").

GFP_ATOMIC has multiple bits set and the check for !(gfp & GFP_ATOMIC)
isn't enough.

The reason behind this condition is to check whether we can potentially
do a sleeping memory allocation.  Use gfpflags_allow_blocking() instead
which should be more robust.

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/mips/mm/dma-default.c

@@ -145,7 +145,7 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
 
 	gfp = massage_gfp_flags(dev, gfp);
 
-	if (IS_ENABLED(CONFIG_DMA_CMA) && !(gfp & GFP_ATOMIC))
+	if (IS_ENABLED(CONFIG_DMA_CMA) && gfpflags_allow_blocking(gfp))
 		page = dma_alloc_from_contiguous(dev,
 					count, get_order(size));
 	if (!page)