[S390] Optional ZONE_DMA for s390.

[S390] Optional ZONE_DMA for s390.

[Martin Schwidefsky]

From: Heiko Carstens <heiko.carstens@de.ibm.com>

[S390] Optional ZONE_DMA for s390.
    
Disable ZONE_DMA on 31-bit. All memory is addressable by all
devices and we do not need any special memory pool.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 arch/s390/Kconfig   |    4 ++--
 arch/s390/mm/init.c |    2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff -urpN linux-2.6/arch/s390/Kconfig linux-2.6-patched/arch/s390/Kconfig
--- linux-2.6/arch/s390/Kconfig	2007-02-21 10:47:06.000000000 +0100
+++ linux-2.6-patched/arch/s390/Kconfig	2007-02-21 10:47:27.000000000 +0100
@@ -8,8 +8,8 @@ config MMU
 	default y
 
 config ZONE_DMA
-	bool
-	default y
+	def_bool y
+	depends on 64BIT
 
 config LOCKDEP_SUPPORT
 	bool
diff -urpN linux-2.6/arch/s390/mm/init.c linux-2.6-patched/arch/s390/mm/init.c
--- linux-2.6/arch/s390/mm/init.c	2007-02-21 10:47:06.000000000 +0100
+++ linux-2.6-patched/arch/s390/mm/init.c	2007-02-21 10:47:27.000000000 +0100
@@ -141,7 +141,9 @@ void __init paging_init(void)
 	__raw_local_irq_ssm(ssm_mask);
 
 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+#ifdef CONFIG_ZONE_DMA
 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
+#endif
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 	free_area_init_nodes(max_zone_pfns);
 }
-- 
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