[PATCH 1/1] s390/dma: provide proper ARCH_ZONE_DMA_BITS value

[Halil Pasic <pasic@linux.ibm.com>]

On s390 ZONE_DMA is up to 2G, i.e. ARCH_ZONE_DMA_BITS should be 31 bits.
The current value is 24 and makes __dma_direct_alloc_pages() take a
wrong turn first (but __dma_direct_alloc_pages() recovers then).

Let's correct ARCH_ZONE_DMA_BITS value and avoid wrong turns.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Petr Tesarik <ptesarik@suse.cz>
Fixes: c61e9637340e ("dma-direct: add support for allocation from
ZONE_DMA and ZONE_DMA32")
---
 arch/s390/include/asm/dma.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/s390/include/asm/dma.h b/arch/s390/include/asm/dma.h
index 6f26f35d4a71..3b0329665b13 100644
--- a/arch/s390/include/asm/dma.h
+++ b/arch/s390/include/asm/dma.h
@@ -10,6 +10,7 @@
  * by the 31 bit heritage.
  */
 #define MAX_DMA_ADDRESS         0x80000000
+#define ARCH_ZONE_DMA_BITS      31
 
 #ifdef CONFIG_PCI
 extern int isa_dma_bridge_buggy;
-- 
2.17.1