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[v9,03/21] arm64: mm: Add p?d_leaf() definitions

Message ID 20190722154210.42799-4-steven.price@arm.com (mailing list archive)
State New, archived
Headers show
Series Generic page walk and ptdump | expand

Commit Message

Steven Price July 22, 2019, 3:41 p.m. UTC
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 will be provided by the
p?d_leaf() functions/macros.

For arm64, we already have p?d_sect() macros which we can reuse for

pud_sect() is defined as a dummy function when CONFIG_PGTABLE_LEVELS < 3
or CONFIG_ARM64_64K_PAGES is defined. However when the kernel is
configured this way then architecturally it isn't allowed to have a
large page that this level, and any code using these page walking macros
is implicitly relying on the page size/number of levels being the same as
the kernel. So it is safe to reuse this for p?d_leaf() as it is an
architectural restriction.

CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will@kernel.org>
Signed-off-by: Steven Price <steven.price@arm.com>
 arch/arm64/include/asm/pgtable.h | 2 ++
 1 file changed, 2 insertions(+)
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diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 87a4b2ddc1a1..2c123d59dbff 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -446,6 +446,7 @@  extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
+#define pmd_leaf(pmd)		pmd_sect(pmd)
 #define pud_sect(pud)		(0)
@@ -528,6 +529,7 @@  static inline void pte_unmap(pte_t *pte) { }
 #define pud_none(pud)		(!pud_val(pud))
 #define pud_bad(pud)		(!(pud_val(pud) & PUD_TABLE_BIT))
 #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))
 static inline void set_pud(pud_t *pudp, pud_t pud)