[PATCH AUTOSEL 5.2 75/76] s390/dma: provide proper ARCH_ZONE_DMA_BITS value

[Sasha Levin]

From: Halil Pasic <pasic@xxxxxxxxxxxxx>

[ Upstream commit 1a2dcff881059dedc14fafc8a442664c8dbd60f1 ]

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@xxxxxxxxxxxxx>
Reported-by: Petr Tesarik <ptesarik@xxxxxxx>
Fixes: c61e9637340e ("dma-direct: add support for allocation from ZONE_DMA and ZONE_DMA32")
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/s390/include/asm/page.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index a4d38092530ab..823578c6b9e2c 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -177,6 +177,8 @@ static inline int devmem_is_allowed(unsigned long pfn)
 #define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | \
 				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 
+#define ARCH_ZONE_DMA_BITS	31
+
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
-- 
2.20.1