1 files changed, 20 insertions, 10 deletions

diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
index c21abc77c53e..77c8d9487a9a 100644
--- a/kernel/dma/coherent.c
+++ b/kernel/dma/coherent.c
@@ -132,8 +132,10 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
 
 void dma_release_coherent_memory(struct device *dev)
 {
-	if (dev)
+	if (dev) {
 		_dma_release_coherent_memory(dev->dma_mem);
+		dev->dma_mem = NULL;
+	}
 }
 
 static void *__dma_alloc_from_coherent(struct device *dev,
@@ -328,21 +330,28 @@ int dma_init_global_coherent(phys_addr_t phys_addr, size_t size)
 #include <linux/of_reserved_mem.h>
 
 #ifdef CONFIG_DMA_GLOBAL_POOL
-static struct reserved_mem *dma_reserved_default_memory __initdata;
+static phys_addr_t dma_reserved_default_memory_base __initdata;
+static phys_addr_t dma_reserved_default_memory_size __initdata;
 #endif
 
 static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
 {
-	if (!rmem->priv) {
-		struct dma_coherent_mem *mem;
+	struct dma_coherent_mem *mem = rmem->priv;
 
+	if (!mem) {
 		mem = dma_init_coherent_memory(rmem->base, rmem->base,
 					       rmem->size, true);
 		if (IS_ERR(mem))
 			return PTR_ERR(mem);
 		rmem->priv = mem;
 	}
-	dma_assign_coherent_memory(dev, rmem->priv);
+
+	/* Warn if the device potentially can't use the reserved memory */
+	if (mem->device_base + rmem->size - 1 >
+	    min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit))
+		dev_warn(dev, "reserved memory is beyond device's set DMA address range\n");
+
+	dma_assign_coherent_memory(dev, mem);
 	return 0;
 }
 
@@ -374,9 +383,10 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem)
 
 #ifdef CONFIG_DMA_GLOBAL_POOL
 	if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) {
-		WARN(dma_reserved_default_memory,
+		WARN(dma_reserved_default_memory_size,
 		     "Reserved memory: region for default DMA coherent area is redefined\n");
-		dma_reserved_default_memory = rmem;
+		dma_reserved_default_memory_base = rmem->base;
+		dma_reserved_default_memory_size = rmem->size;
 	}
 #endif
 
@@ -389,10 +399,10 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem)
 #ifdef CONFIG_DMA_GLOBAL_POOL
 static int __init dma_init_reserved_memory(void)
 {
-	if (!dma_reserved_default_memory)
+	if (!dma_reserved_default_memory_size)
 		return -ENOMEM;
-	return dma_init_global_coherent(dma_reserved_default_memory->base,
-					dma_reserved_default_memory->size);
+	return dma_init_global_coherent(dma_reserved_default_memory_base,
+					dma_reserved_default_memory_size);
 }
 core_initcall(dma_init_reserved_memory);
 #endif /* CONFIG_DMA_GLOBAL_POOL */