[RFC V2 26/37] mm, dmem: introduce pud_special() for dmem huge pud support

[yulei . kernel]

From: Yulei Zhang <yuleixzhang@xxxxxxxxxxx>

pud_special() will check both _PAGE_SPECIAL and _PAGE_DMEM bit
as pmd_special() does.

Signed-off-by: Chen Zhuo <sagazchen@xxxxxxxxxxx>
Signed-off-by: Yulei Zhang <yuleixzhang@xxxxxxxxxxx>
---
 arch/x86/include/asm/pgtable.h | 13 +++++++++++++
 include/linux/pgtable.h        | 10 ++++++++++
 2 files changed, 23 insertions(+)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 6ce85d4..9e36d42 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -281,6 +281,12 @@ static inline int pmd_special(pmd_t pmd)
 	return (pmd_val(pmd) & (_PAGE_SPECIAL | _PAGE_DMEM)) ==
 		(_PAGE_SPECIAL | _PAGE_DMEM);
 }
+
+static inline int pud_special(pud_t pud)
+{
+	return (pud_val(pud) & (_PAGE_SPECIAL | _PAGE_DMEM)) ==
+		(_PAGE_SPECIAL | _PAGE_DMEM);
+}
 #endif
 
 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
@@ -516,6 +522,13 @@ static inline pud_t pud_mkdirty(pud_t pud)
 	return pud_set_flags(pud, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);
 }
 
+#ifdef CONFIG_ARCH_HAS_PTE_DMEM
+static inline pud_t pud_mkdmem(pud_t pud)
+{
+	return pud_set_flags(pud, _PAGE_SPECIAL | _PAGE_DMEM);
+}
+#endif
+
 static inline pud_t pud_mkdevmap(pud_t pud)
 {
 	return pud_set_flags(pud, _PAGE_DEVMAP);
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 30342b8..0ef03ff 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1167,6 +1167,16 @@ static inline int pmd_special(pmd_t pmd)
 {
 	return 0;
 }
+
+static inline pud_t pud_mkdmem(pud_t pud)
+{
+	return pud;
+}
+
+static inline int pud_special(pud_t pud)
+{
+	return 0;
+}
 #endif
 
 #ifndef pmd_read_atomic
-- 
1.8.3.1