s390/mm: fix MAX_DMA_ADDRESS physical vs virtual confusion

MAX_DMA_ADDRESS is defined and treated as a physical address,
whereas it should be virtual.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/include/asm/dma.h

@@ -9,6 +9,6 @@
  * to DMA. It _is_ used for the s390 memory zone split at 2GB caused
  * by the 31 bit heritage.
  */
-#define MAX_DMA_ADDRESS         0x80000000
+#define MAX_DMA_ADDRESS		__va(0x80000000)
 
 #endif /* _ASM_S390_DMA_H */

arch/s390/mm/init.c

@@ -98,7 +98,7 @@ void __init paging_init(void)
 	sparse_init();
 	zone_dma_bits = 31;
 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
-	max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
+	max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS);
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 	free_area_init(max_zone_pfns);
 }