arm64: Use swiotlb late initialisation

Since arm64 does not support ISA, there is no need for early swiotlb
initialisation. This patch switches the DMA mapping code to
swiotlb_tlb_late_init_with_default_size(). A side effect of this is that
GFP_DMA is used for the swiotlb buffer and devices with a 32-bit
coherent mask are correctly supported.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/mm/dma-mapping.c

@@ -93,11 +93,17 @@ static struct dma_map_ops coherent_swiotlb_dma_ops = {
 	.mapping_error = swiotlb_dma_mapping_error,
 };
 
-void __init arm64_swiotlb_init(void)
+extern int swiotlb_late_init_with_default_size(size_t default_size);
+
+static int __init swiotlb_late_init(void)
 {
+	size_t swiotlb_size = min(SZ_64M, MAX_ORDER_NR_PAGES << PAGE_SHIFT);
+
 	dma_ops = &coherent_swiotlb_dma_ops;
-	swiotlb_init(1);
+
+	return swiotlb_late_init_with_default_size(swiotlb_size);
 }
+subsys_initcall(swiotlb_late_init);
 
 #define PREALLOC_DMA_DEBUG_ENTRIES	4096
 

arch/arm64/mm/init.c

@@ -262,8 +262,6 @@ static void __init free_unused_memmap(void)
  */
 void __init mem_init(void)
 {
-	arm64_swiotlb_init();
-
 	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
 
 #ifndef CONFIG_SPARSEMEM_VMEMMAP