mm: Some arch may want to use HPAGE_PMD related values as variables
With next generation power processor, we are having a new mmu model
[1] that require us to maintain a different linux page table format.
Inorder to support both current and future ppc64 systems with a single
kernel we need to make sure kernel can select between different page
table format at runtime. With the new MMU (radix MMU) added, we will
have two different pmd hugepage size 16MB for hash model and 2MB for
Radix model. Hence make HPAGE_PMD related values as a variable.
Actual conversion of HPAGE_PMD to a variable for ppc64 happens in a
followup patch.
[1] http://ibm.biz/power-isa3 (Needs registration).
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/include/linux/bug.h b/include/linux/bug.h
index 7f48186..e51b070 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -20,6 +20,7 @@
#define BUILD_BUG_ON_MSG(cond, msg) (0)
#define BUILD_BUG_ON(condition) (0)
#define BUILD_BUG() (0)
+#define MAYBE_BUILD_BUG_ON(cond) (0)
#else /* __CHECKER__ */
/* Force a compilation error if a constant expression is not a power of 2 */
@@ -83,6 +84,14 @@
*/
#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
+#define MAYBE_BUILD_BUG_ON(cond) \
+ do { \
+ if (__builtin_constant_p((cond))) \
+ BUILD_BUG_ON(cond); \
+ else \
+ BUG_ON(cond); \
+ } while (0)
+
#endif /* __CHECKER__ */
#ifdef CONFIG_GENERIC_BUG
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 459fd25..f12513a 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -111,9 +111,6 @@
__split_huge_pmd(__vma, __pmd, __address); \
} while (0)
-#if HPAGE_PMD_ORDER >= MAX_ORDER
-#error "hugepages can't be allocated by the buddy allocator"
-#endif
extern int hugepage_madvise(struct vm_area_struct *vma,
unsigned long *vm_flags, int advice);
extern void vma_adjust_trans_huge(struct vm_area_struct *vma,