linux-kernel - [PATCH -next 1/4] riscv: mm: add _PAGE

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Message-ID: <20210430082850.462609-2-sunnanyong@huawei.com>
Date:   Fri, 30 Apr 2021 16:28:47 +0800
From:   Nanyong Sun <sunnanyong@...wei.com>
To:     <paul.walmsley@...ive.com>, <palmer@...belt.com>,
        <aou@...s.berkeley.edu>
CC:     <linux-riscv@...ts.infradead.org>, <linux-kernel@...r.kernel.org>,
        <palmerdabbelt@...gle.com>, <atish.patra@....com>,
        <wangkefeng.wang@...wei.com>, <sunnanyong@...wei.com>
Subject: [PATCH -next 1/4] riscv: mm: add _PAGE_LEAF macro

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@...wei.com>
---
 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