[PATCH v3 17/34] riscv: mm: Add p?d_large() definitions

[Steven Price]

walk_page_range() is going to be allowed to walk page tables other than
those of user space. For this it needs to know when it has reached a
'leaf' entry in the page tables. This information is provided by the
p?d_large() functions/macros.

For riscv a page is large when it has a read, write or execute bit
set on it.

CC: Palmer Dabbelt <palmer@xxxxxxxxxx>
CC: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
CC: linux-riscv@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
 arch/riscv/include/asm/pgtable-64.h | 6 ++++++
 arch/riscv/include/asm/pgtable.h    | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
index 7aa0ea9bd8bb..6763c44d338d 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -51,6 +51,12 @@ static inline int pud_bad(pud_t pud)
 	return !pud_present(pud);
 }
 
+static inline int pud_large(pud_t pud)
+{
+	return pud_present(pud)
+		&& (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+}
+
 static inline void set_pud(pud_t *pudp, pud_t pud)
 {
 	*pudp = pud;
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 16301966d65b..17624d7e7e8b 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -111,6 +111,12 @@ static inline int pmd_bad(pmd_t pmd)
 	return !pmd_present(pmd);
 }
 
+static inline int pmd_large(pmd_t pmd)
+{
+	return pmd_present(pmd)
+		&& (pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+}
+
 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 {
 	*pmdp = pmd;
-- 
2.20.1