dma-contiguous: remove dev_set_cma_area

dev_set_cma_area contains a trivial assignment.  It has just three
callers that all have a non-NULL device and depend on CONFIG_DMA_CMA,
so remove the wrapper.
Signed-off-by: Christoph Hellwig <hch@lst.de>

arch/arm/mach-davinci/devices-da8xx.c

@@ -905,7 +905,7 @@ void __init da8xx_rproc_reserve_cma(void)
 			__func__, ret);
 		return;
 	}
-	dev_set_cma_area(&da8xx_dsp.dev, cma);
+	da8xx_dsp.dev.cma_area = cma;
 	rproc_mem_inited = true;
 }
 #else

include/linux/dma-contiguous.h

@@ -66,12 +66,6 @@ static inline struct cma *dev_get_cma_area(struct device *dev)
 	return dma_contiguous_default_area;
 }
 
-static inline void dev_set_cma_area(struct device *dev, struct cma *cma)
-{
-	if (dev)
-		dev->cma_area = cma;
-}
-
 static inline void dma_contiguous_set_default(struct cma *cma)
 {
 	dma_contiguous_default_area = cma;
@@ -97,8 +91,6 @@ static inline struct cma *dev_get_cma_area(struct device *dev)
 	return NULL;
 }
 
-static inline void dev_set_cma_area(struct device *dev, struct cma *cma) { }
-
 static inline void dma_contiguous_set_default(struct cma *cma) { }
 
 static inline void dma_contiguous_reserve(phys_addr_t limit) { }

kernel/dma/contiguous.c

@@ -359,14 +359,14 @@ void dma_free_contiguous(struct device *dev, struct page *page, size_t size)
 
 static int rmem_cma_device_init(struct reserved_mem *rmem, struct device *dev)
 {
-	dev_set_cma_area(dev, rmem->priv);
+	dev->cma_area = rmem->priv;
 	return 0;
 }
 
 static void rmem_cma_device_release(struct reserved_mem *rmem,
 				    struct device *dev)
 {
-	dev_set_cma_area(dev, NULL);
+	dev->cma_area = NULL;
 }
 
 static const struct reserved_mem_ops rmem_cma_ops = {