[PATCH 2/4] mm: introduce mm_[p4d|pud|pmd]_folded

[Martin Schwidefsky]

Add three architecture overrideable functions to test if the
p4d, pud, or pmd layer of a page table is folded or not.

Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
 include/asm-generic/pgtable.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 5657a20..359fb93 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -1127,4 +1127,20 @@ static inline bool arch_has_pfn_modify_check(void)
 #endif
 #endif
 
+/*
+ * On some architectures it depends on the mm if the p4d/pud or pmd
+ * layer of the page table hierarchy is folded or not.
+ */
+#ifndef mm_p4d_folded
+#define mm_p4d_folded(mm)	__is_defined(__PAGETABLE_P4D_FOLDED)
+#endif
+
+#ifndef mm_pud_folded
+#define mm_pud_folded(mm)	__is_defined(__PAGETABLE_PUD_FOLDED)
+#endif
+
+#ifndef mm_pmd_folded
+#define mm_pmd_folded(mm)	__is_defined(__PAGETABLE_PMD_FOLDED)
+#endif
+
 #endif /* _ASM_GENERIC_PGTABLE_H */
-- 
2.7.4