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_leaf() functions/macros.

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

CC: Palmer Dabbelt <redacted>
CC: Albert Ou <aou@eecs.berkeley.edu>
CC: linux-riscv@lists.infradead.org
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Acked-by: Paul Walmsley <redacted> # for arch/riscv
Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/riscv/include/asm/pgtable-64.h | 7 +++++++
 arch/riscv/include/asm/pgtable.h    | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
index 74630989006d..4c4d2c65ba6c 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h

@@ -43,6 +43,13 @@ static inline int pud_bad(pud_t pud)
        return !pud_present(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));
+}
+
 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 7255f2d8395b..3aa972dda75a 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h

@@ -130,6 +130,13 @@ static inline int pmd_bad(pmd_t pmd)
        return !pmd_present(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));
+}
+
 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 {
        *pmdp = pmd;
--

2.20.1


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