ARM: DMA-Mapping: add function for setting coherent pool size from platform code

[can-eth-gw-linux.git] / arch / arm / mm / dma-mapping.c

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4e7d1182e8a3a59270073b5cb3b348e0bd690ef8..d1cc9c1d3566fd10680ed2fe16d6e4ab84fc152d 100644 (file)
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -267,6 +267,8 @@ static void __dma_free_remap(void *cpu_addr, size_t size)
        vunmap(cpu_addr);
 }
 
+#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
+
 struct dma_pool {
        size_t size;
        spinlock_t lock;
@@ -277,7 +279,7 @@ struct dma_pool {
 };
 
 static struct dma_pool atomic_pool = {
-       .size = SZ_256K,
+       .size = DEFAULT_DMA_COHERENT_POOL_SIZE,
 };
 
 static int __init early_coherent_pool(char *p)
@@ -287,6 +289,21 @@ static int __init early_coherent_pool(char *p)
 }
 early_param("coherent_pool", early_coherent_pool);
 
+void __init init_dma_coherent_pool_size(unsigned long size)
+{
+       /*
+        * Catch any attempt to set the pool size too late.
+        */
+       BUG_ON(atomic_pool.vaddr);
+
+       /*
+        * Set architecture specific coherent pool size only if
+        * it has not been changed by kernel command line parameter.
+        */
+       if (atomic_pool.size == DEFAULT_DMA_COHERENT_POOL_SIZE)
+               atomic_pool.size = size;
+}
+
 /*
  * Initialise the coherent pool for atomic allocations.
  */