[PATCH v7 03/20] mips: mm: Add p?d_large() definitions

Steven Price steven.price at arm.com
Thu Mar 28 08:20:47 PDT 2019


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_large() functions/macros.

For mips, we only support large pages on 64 bit.

For 64 bit if _PAGE_HUGE is defined we can simply look for it. When not
defined we can be confident that there are no large pages in existence
and fall back on the generic implementation (added in a later patch)
which returns 0.

CC: Ralf Baechle <ralf at linux-mips.org>
CC: Paul Burton <paul.burton at mips.com>
CC: James Hogan <jhogan at kernel.org>
CC: linux-mips at vger.kernel.org
Signed-off-by: Steven Price <steven.price at arm.com>
Acked-by: Paul Burton <paul.burton at mips.com>
---
 arch/mips/include/asm/pgtable-64.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
index 93a9dce31f25..42162877ac62 100644
--- a/arch/mips/include/asm/pgtable-64.h
+++ b/arch/mips/include/asm/pgtable-64.h
@@ -273,6 +273,10 @@ static inline int pmd_present(pmd_t pmd)
 	return pmd_val(pmd) != (unsigned long) invalid_pte_table;
 }
 
+#ifdef _PAGE_HUGE
+#define pmd_large(pmd)	((pmd_val(pmd) & _PAGE_HUGE) != 0)
+#endif
+
 static inline void pmd_clear(pmd_t *pmdp)
 {
 	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
@@ -297,6 +301,10 @@ static inline int pud_present(pud_t pud)
 	return pud_val(pud) != (unsigned long) invalid_pmd_table;
 }
 
+#ifdef _PAGE_HUGE
+#define pud_large(pud)	((pud_val(pud) & _PAGE_HUGE) != 0)
+#endif
+
 static inline void pud_clear(pud_t *pudp)
 {
 	pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
-- 
2.20.1




More information about the linux-arm-kernel mailing list