arm64: dma-mapping: check whether cma area is initialized or not

If CMA is turned on and CMA size is set to zero, kernel should
behave as if CMA was not enabled at compile time.
Every dma allocation should check existence of cma area
before requesting memory.

Arm has done this by commit e464ef16c4f0 ("arm: dma-mapping: add
checking cma area initialized"), also do this for arm64.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 0bcc4bc94b4ad3b4d72d735dc7e88a190c2e5cbe..99224dcebdc51d40cb2dff423280727ec44bacd3 100644 (file)
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -100,7 +100,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size,
        if (IS_ENABLED(CONFIG_ZONE_DMA) &&
            dev->coherent_dma_mask <= DMA_BIT_MASK(32))
                flags |= GFP_DMA;
-       if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_WAIT)) {
+       if (dev_get_cma_area(dev) && (flags & __GFP_WAIT)) {
                struct page *page;
                void *addr;