On 10/7/19 11:38 AM, Steven Price wrote:
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 <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 | 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..e88a8e8acbdf 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..b9a679153265 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;
Hi Steven,
The way you check leaf entries is correct: we do the same for hugepages.
So is
there a reason you did not use the pmd/pud_huge functions that are
defined in
arch/riscv/mm/hugetlbpage.c ?
Anyway, FWIW:
Reviewed-by: Alexandre Ghiti <alex@xxxxxxxx>
Thanks,
Alex
