sparc64: Add FORCE_MAX_ZONEORDER and default to 13

This change allows ATU (new IOMMU) in SPARC systems to request
large (32M) contiguous memory during boot for creating IOTSB backing
store.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 0 deletions

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index b23c76b42d6e..5202eb4ba2db 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -89,6 +89,10 @@ config ARCH_DEFCONFIG
 config ARCH_PROC_KCORE_TEXT
         def_bool y
 
+config ARCH_ATU
+        bool
+        default y if SPARC64
+
 config IOMMU_HELPER
         bool
         default y if SPARC64
@@ -304,6 +308,20 @@ config ARCH_SPARSEMEM_ENABLE
 config ARCH_SPARSEMEM_DEFAULT
         def_bool y if SPARC64
 
+config FORCE_MAX_ZONEORDER
+        int "Maximum zone order"
+        default "13"
+        help
+          The kernel memory allocator divides physically contiguous memory
+          blocks into "zones", where each zone is a power of two number of
+          pages.  This option selects the largest power of two that the kernel
+          keeps in the memory allocator.  If you need to allocate very large
+          blocks of physically contiguous memory, then you may need to
+          increase this value.
+
+          This config option is actually maximum order plus one. For example,
+          a value of 13 means that the largest free memory block is 2^12 pages.
+
 source "mm/Kconfig"
 
 if SPARC64