1 files changed, 6 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c
index bd1a2aba599f..735979764cd4 100644
--- a/arch/powerpc/kernel/dma-swiotlb.c
+++ b/arch/powerpc/kernel/dma-swiotlb.c
@@ -106,10 +106,14 @@ int __init swiotlb_setup_bus_notifier(void)
         return 0;
 }
 
-void swiotlb_detect_4g(void)
+void __init swiotlb_detect_4g(void)
 {
-        if ((memblock_end_of_DRAM() - 1) > 0xffffffff)
+        if ((memblock_end_of_DRAM() - 1) > 0xffffffff) {
                 ppc_swiotlb_enable = 1;
+#ifdef CONFIG_ZONE_DMA32
+                limit_zone_pfn(ZONE_DMA32, (1ULL << 32) >> PAGE_SHIFT);
+#endif
+        }
 }
 
 static int __init swiotlb_late_init(void)