dma-mapping: remove the DMA_MEMORY_EXCLUSIVE flag

All users of dma_declare_coherent want their allocations to be
exclusive, so default to exclusive allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/dma/coherent.c

@@ -14,7 +14,6 @@ struct dma_coherent_mem {
 	dma_addr_t	device_base;
 	unsigned long	pfn_base;
 	int		size;
-	int		flags;
 	unsigned long	*bitmap;
 	spinlock_t	spinlock;
 	bool		use_dev_dma_pfn_offset;
@@ -38,9 +37,9 @@ static inline dma_addr_t dma_get_device_base(struct device *dev,
 		return mem->device_base;
 }
 
-static int dma_init_coherent_memory(
-	phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags,
-	struct dma_coherent_mem **mem)
+static int dma_init_coherent_memory(phys_addr_t phys_addr,
+		dma_addr_t device_addr, size_t size,
+		struct dma_coherent_mem **mem)
 {
 	struct dma_coherent_mem *dma_mem = NULL;
 	void *mem_base = NULL;
@@ -73,7 +72,6 @@ static int dma_init_coherent_memory(
 	dma_mem->device_base = device_addr;
 	dma_mem->pfn_base = PFN_DOWN(phys_addr);
 	dma_mem->size = pages;
-	dma_mem->flags = flags;
 	spin_lock_init(&dma_mem->spinlock);
 
 	*mem = dma_mem;
@@ -110,12 +108,12 @@ static int dma_assign_coherent_memory(struct device *dev,
 }
 
 int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
-				dma_addr_t device_addr, size_t size, int flags)
+				dma_addr_t device_addr, size_t size)
 {
 	struct dma_coherent_mem *mem;
 	int ret;
 
-	ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags, &mem);
+	ret = dma_init_coherent_memory(phys_addr, device_addr, size, &mem);
 	if (ret)
 		return ret;
 
@@ -190,15 +188,7 @@ int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
 		return 0;
 
 	*ret = __dma_alloc_from_coherent(mem, size, dma_handle);
-	if (*ret)
-		return 1;
-
-	/*
-	 * In the case where the allocation can not be satisfied from the
-	 * per-device area, try to fall back to generic memory if the
-	 * constraints allow it.
-	 */
-	return mem->flags & DMA_MEMORY_EXCLUSIVE;
+	return 1;
 }
 
 void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle)
@@ -327,8 +317,7 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
 
 	if (!mem) {
 		ret = dma_init_coherent_memory(rmem->base, rmem->base,
-					       rmem->size,
-					       DMA_MEMORY_EXCLUSIVE, &mem);
+					       rmem->size, &mem);
 		if (ret) {
 			pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
 				&rmem->base, (unsigned long)rmem->size / SZ_1M);