[PATCH] optional ZONE_DMA: optional ZONE_DMA for ia64

ZONE_DMA less operation for IA64 SGI platform

Disable ZONE_DMA for SGI SN2.  All memory is addressable by all devices and we
do not need any special memory pool.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 11 insertions, 3 deletions

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 549ead597934..db185f34e341 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -25,8 +25,8 @@ config 64BIT
         default y
 
 config ZONE_DMA
-        bool
-        default y
+        def_bool y
+        depends on !IA64_SGI_SN2
 
 config MMU
         bool
diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c
index 63e6d49c5813..ca4d41e5f177 100644
--- a/arch/ia64/mm/contig.c
+++ b/arch/ia64/mm/contig.c
@@ -259,9 +259,11 @@ paging_init (void)
         num_physpages = 0;
         efi_memmap_walk(count_pages, &num_physpages);
 
-        max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+#ifdef CONFIG_ZONE_DMA
+        max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
         max_zone_pfns[ZONE_DMA] = max_dma;
+#endif
         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 
 #ifdef CONFIG_VIRTUAL_MEM_MAP
diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index 6eae596c509d..16835108bb5b 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -37,7 +37,9 @@ struct early_node_data {
         unsigned long pernode_size;
         struct bootmem_data bootmem_data;
         unsigned long num_physpages;
+#ifdef CONFIG_ZONE_DMA
         unsigned long num_dma_physpages;
+#endif
         unsigned long min_pfn;
         unsigned long max_pfn;
 };
@@ -633,9 +635,11 @@ static __init int count_node_pages(unsigned long start, unsigned long len, int n
         unsigned long end = start + len;
 
         mem_data[node].num_physpages += len >> PAGE_SHIFT;
+#ifdef CONFIG_ZONE_DMA
         if (start <= __pa(MAX_DMA_ADDRESS))
                 mem_data[node].num_dma_physpages +=
                         (min(end, __pa(MAX_DMA_ADDRESS)) - start) >>PAGE_SHIFT;
+#endif
         start = GRANULEROUNDDOWN(start);
         start = ORDERROUNDDOWN(start);
         end = GRANULEROUNDUP(end);
@@ -688,7 +692,9 @@ void __init paging_init(void)
         }
 
         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+#ifdef CONFIG_ZONE_DMA
         max_zone_pfns[ZONE_DMA] = max_dma;
+#endif
         max_zone_pfns[ZONE_NORMAL] = max_pfn;
         free_area_init_nodes(max_zone_pfns);