[PATCH -next 1/4] riscv: mm: add _PAGE_LEAF macro

From: Nanyong Sun
Date: Fri Apr 30 2021 - 03:56:45 EST


In riscv, a page table entry is leaf when any bit of read, write,
or execute bit is set. So add a macro:_PAGE_LEAF instead of
(_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC), which is frequently used
to determine if it is a leaf page. This make code easier to read,
without any functional change.

Signed-off-by: Nanyong Sun <sunnanyong@xxxxxxxxxx>
---
arch/riscv/include/asm/pgtable-64.h | 3 +--
arch/riscv/include/asm/pgtable-bits.h | 5 +++++
arch/riscv/include/asm/pgtable.h | 6 ++----
3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
index f3b0da64c..e3b7c5dd6 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -46,8 +46,7 @@ static inline int pud_bad(pud_t pud)
#define pud_leaf pud_leaf
static inline int pud_leaf(pud_t pud)
{
- return pud_present(pud) &&
- (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+ return pud_present(pud) && (pud_val(pud) & _PAGE_LEAF);
}

static inline void set_pud(pud_t *pudp, pud_t pud)
diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h
index bbaeb5d35..2ee413912 100644
--- a/arch/riscv/include/asm/pgtable-bits.h
+++ b/arch/riscv/include/asm/pgtable-bits.h
@@ -39,5 +39,10 @@
#define _PAGE_CHG_MASK (~(unsigned long)(_PAGE_PRESENT | _PAGE_READ | \
_PAGE_WRITE | _PAGE_EXEC | \
_PAGE_USER | _PAGE_GLOBAL))
+/*
+ * when all of R/W/X are zero, the PTE is a pointer to the next level
+ * of the page table; otherwise, it is a leaf PTE.
+ */
+#define _PAGE_LEAF (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)

#endif /* _ASM_RISCV_PGTABLE_BITS_H */
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 80e63a93e..f489e412f 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -166,8 +166,7 @@ static inline int pmd_bad(pmd_t pmd)
#define pmd_leaf pmd_leaf
static inline int pmd_leaf(pmd_t pmd)
{
- return pmd_present(pmd) &&
- (pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+ return pmd_present(pmd) && (pmd_val(pmd) & _PAGE_LEAF);
}

static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
@@ -243,8 +242,7 @@ static inline int pte_exec(pte_t pte)

static inline int pte_huge(pte_t pte)
{
- return pte_present(pte)
- && (pte_val(pte) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+ return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
}

static inline int pte_dirty(pte_t pte)
--
2.25.1