[PATCH 5.10 32/86] arm64/mm: Remove [PUD|PMD]_TABLE_BIT from [pud|pmd]_bad()

Greg Kroah-Hartman
2022-04-26T08:52:57Z

From: Anshuman Khandual <anshuman.khandual@arm.com>

[ Upstream commit e377ab82311af95c99648c6424a6b888a0ccb102 ]

Semantics wise, [pud|pmd]_bad() have always implied that a given [PUD|PMD]
entry does not have a pointer to the next level page table. This had been
made clear in the commit a1c76574f345 ("arm64: mm: use *_sect to check for
section maps"). Hence explicitly check for a table entry rather than just
testing a single bit. This basically redefines [pud|pmd]_bad() in terms of
[pud|pmd]_table() making the semantics clear.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/1620644871-26280-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/include/asm/pgtable.h | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index f3a70dc7c594..9cf8e304bb56 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -512,13 +512,12 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,

#define pmd_none(pmd) (!pmd_val(pmd))

-#define pmd_bad(pmd) (!(pmd_val(pmd) & PMD_TABLE_BIT))
-
#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \
PMD_TYPE_TABLE)
#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \
PMD_TYPE_SECT)
#define pmd_leaf(pmd) pmd_sect(pmd)
+#define pmd_bad(pmd) (!pmd_table(pmd))

#if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
static inline bool pud_sect(pud_t pud) { return false; }
@@ -602,7 +601,7 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
pr_err("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e))

#define pud_none(pud) (!pud_val(pud))
-#define pud_bad(pud) (!(pud_val(pud) & PUD_TABLE_BIT))
+#define pud_bad(pud) (!pud_table(pud))
#define pud_present(pud) pte_present(pud_pte(pud))
#define pud_leaf(pud) pud_sect(pud)
#define pud_valid(pud) pte_valid(pud_pte(pud))
--
2.35.1