IA64: SPARSEMEM_VMEMMAP 16K page size support

Equip IA64 sparsemem with a virtual memmap.  This is similar to the existing
CONFIG_VIRTUAL_MEM_MAP functionality for DISCONTIGMEM.  It uses a PAGE_SIZE
mapping.

This is provided as a minimally intrusive solution.  We split the 128TB
VMALLOC area into two 64TB areas and use one for the virtual memmap.

This should replace CONFIG_VIRTUAL_MEM_MAP long term.

[apw@shadowen.org: convert to new helper based initialisation]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 9 insertions, 0 deletions

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 2e6310b8eab7..802b082e216d 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -348,6 +348,7 @@ config ARCH_FLATMEM_ENABLE
 config ARCH_SPARSEMEM_ENABLE
         def_bool y
         depends on ARCH_DISCONTIGMEM_ENABLE
+        select SPARSEMEM_VMEMMAP_ENABLE
 
 config ARCH_DISCONTIGMEM_DEFAULT
         def_bool y if (IA64_SGI_SN2 || IA64_GENERIC || IA64_HP_ZX1 || IA64_HP_ZX1_SWIOTLB)
diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index 0d34585058c8..5628067a74d2 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -715,3 +715,11 @@ void arch_refresh_nodedata(int update_node, pg_data_t *update_pgdat)
         scatter_node_data();
 }
 #endif
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+int __meminit vmemmap_populate(struct page *start_page,
+                                                unsigned long size, int node)
+{
+        return vmemmap_populate_basepages(start_page, size, node);
+}
+#endif