[RFC PATCH v2 04/11] riscv: pgtable: Fixup _PAGE_CHG_MASK usage

guoren
2021-06-06T09:07:52Z

From: Guo Ren <guoren@linux.alibaba.com>

We should masks all attributes BITS first, and then
using '>> _PAGE_PFN_SHIFT' to get the final PFN value.

Adding '& _PAGE_CHG_MASK' makes the code semantics more accurate.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Liu Shaohua <liush@allwinnertech.com>
Cc: Anup Patel <anup.patel@wdc.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Drew Fustini <drew@beagleboard.org>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Wei Fu <wefu@redhat.com>
Cc: Wei Wu <lazyparser@gmail.com>
---
arch/riscv/include/asm/pgtable-64.h | 8 +++++---
arch/riscv/include/asm/pgtable.h | 6 +++---
2 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 f3b0da6..cbf9acf 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -62,12 +62,14 @@ static inline void pud_clear(pud_t *pudp)

static inline unsigned long pud_page_vaddr(pud_t pud)
{
- return (unsigned long)pfn_to_virt(pud_val(pud) >> _PAGE_PFN_SHIFT);
+ return (unsigned long)pfn_to_virt(
+ (pud_val(pud) & _PAGE_CHG_MASK) >> _PAGE_PFN_SHIFT);
}

static inline struct page *pud_page(pud_t pud)
{
- return pfn_to_page(pud_val(pud) >> _PAGE_PFN_SHIFT);
+ return pfn_to_page(
+ (pud_val(pud) & _PAGE_CHG_MASK) >> _PAGE_PFN_SHIFT);
}

static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot)
@@ -77,7 +79,7 @@ static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot)

static inline unsigned long _pmd_pfn(pmd_t pmd)
{
- return pmd_val(pmd) >> _PAGE_PFN_SHIFT;
+ return (pmd_val(pmd) & _PAGE_CHG_MASK) >> _PAGE_PFN_SHIFT;
}

#define pmd_ERROR(e) \
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 346a3c6..13a79643 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -217,12 +217,12 @@ static inline unsigned long _pgd_pfn(pgd_t pgd)

static inline struct page *pmd_page(pmd_t pmd)
{
- return pfn_to_page(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
+ return pfn_to_page((pmd_val(pmd) & _PAGE_CHG_MASK) >> _PAGE_PFN_SHIFT);
}

static inline unsigned long pmd_page_vaddr(pmd_t pmd)
{
- return (unsigned long)pfn_to_virt(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
+ return (unsigned long)pfn_to_virt((pmd_val(pmd) & _PAGE_CHG_MASK) >> _PAGE_PFN_SHIFT);
}

static inline pte_t pmd_pte(pmd_t pmd)
@@ -233,7 +233,7 @@ static inline pte_t pmd_pte(pmd_t pmd)
/* Yields the page frame number (PFN) of a page table entry */
static inline unsigned long pte_pfn(pte_t pte)
{
- return (pte_val(pte) >> _PAGE_PFN_SHIFT);
+ return ((pte_val(pte) & _PAGE_CHG_MASK) >> _PAGE_PFN_SHIFT);
}

#define pte_page(x) pfn_to_page(pte_pfn(x))
--
2.7.4