[PATCH V4] powerpc/hugetlb: Add ABI defines for supported HugeTLB page sizes

[Anshuman Khandual]

This just adds user space exported ABI definitions for 2MB, 16MB, 1GB,
16GB non default huge page sizes to be used with mmap() system call.

Signed-off-by: Anshuman Khandual <khandual at linux.vnet.ibm.com>
---
These defined values will be used along with MAP_HUGETLB while calling
mmap() system call if the desired HugeTLB page size is not the default
one. Follows similar definitions present in x86.

arch/x86/include/uapi/asm/mman.h:#define MAP_HUGE_2MB    (21 << MAP_HUGE_SHIFT)
arch/x86/include/uapi/asm/mman.h:#define MAP_HUGE_1GB    (30 << MAP_HUGE_SHIFT)

Changes in V4:
- Added defines for 512KB and 8MB HugeTLB page sizes per Christophe

Changes in V3:
- Added comment about how these defines will help create 'flags'
  argument for mmap() system call per Balbir

Changes in V2:
- Added definitions for 2MB and 1GB HugeTLB pages per Aneesh

 arch/powerpc/include/uapi/asm/mman.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/powerpc/include/uapi/asm/mman.h b/arch/powerpc/include/uapi/asm/mman.h
index 03c06ba..ebe99c7 100644
--- a/arch/powerpc/include/uapi/asm/mman.h
+++ b/arch/powerpc/include/uapi/asm/mman.h
@@ -29,4 +29,18 @@
 #define MAP_STACK	0x20000		/* give out an address that is best suited for process/thread stacks */
 #define MAP_HUGETLB	0x40000		/* create a huge page mapping */
 
+/*
+ * These constant defines should be used for creating the
+ * 'flags' argument (26:31 bit positions) for mmap() system
+ * call should the caller decide to use non default HugeTLB
+ * page size.
+ */
+#define MAP_HUGE_512KB	(19 << MAP_HUGE_SHIFT)	/* 512KB HugeTLB Page */
+#define MAP_HUGE_1MB	(20 << MAP_HUGE_SHIFT)	/* 1MB   HugeTLB Page */
+#define MAP_HUGE_2MB	(21 << MAP_HUGE_SHIFT)	/* 2MB   HugeTLB Page */
+#define MAP_HUGE_8MB	(23 << MAP_HUGE_SHIFT)	/* 8MB   HugeTLB Page */
+#define MAP_HUGE_16MB	(24 << MAP_HUGE_SHIFT)	/* 16MB  HugeTLB Page */
+#define MAP_HUGE_1GB	(30 << MAP_HUGE_SHIFT)	/* 1GB   HugeTLB Page */
+#define MAP_HUGE_16GB	(34 << MAP_HUGE_SHIFT)	/* 16GB  HugeTLB Page */
+
 #endif /* _UAPI_ASM_POWERPC_MMAN_H */
-- 
1.8.5.2