diff mbox series

[v1,6/7] powerpc/pgtable: remove _PAGE_BIT_SWAP_TYPE for book3s

Message ID 20220315141837.137118-7-david@redhat.com (mailing list archive)
State New, archived
Headers show
Series mm: COW fixes part 3: reliable GUP R/W FOLL_GET of anonymous pages | expand

Commit Message

David Hildenbrand March 15, 2022, 2:18 p.m. UTC
The swap type is simply stored in bits 0x1f of the swap pte. Let's
simplify by just getting rid of _PAGE_BIT_SWAP_TYPE. It's not like that
we can simply change it: _PAGE_SWP_SOFT_DIRTY would suddenly fall into
_RPAGE_RSV1, which isn't possible and would make the
BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_SOFT_DIRTY) angry.

While at it, make it clearer which bit we're actually using for
_PAGE_SWP_SOFT_DIRTY by just using the proper define and introduce and
use SWP_TYPE_MASK.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/powerpc/include/asm/book3s/64/pgtable.h | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 875730d5af40..8e98375d5c4a 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -13,7 +13,6 @@ 
 /*
  * Common bits between hash and Radix page table
  */
-#define _PAGE_BIT_SWAP_TYPE	0
 
 #define _PAGE_EXEC		0x00001 /* execute permission */
 #define _PAGE_WRITE		0x00002 /* write access allowed */
@@ -751,17 +750,16 @@  static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 	 * Don't have overlapping bits with _PAGE_HPTEFLAGS	\
 	 * We filter HPTEFLAGS on set_pte.			\
 	 */							\
-	BUILD_BUG_ON(_PAGE_HPTEFLAGS & (0x1f << _PAGE_BIT_SWAP_TYPE)); \
+	BUILD_BUG_ON(_PAGE_HPTEFLAGS & SWP_TYPE_MASK); \
 	BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_SOFT_DIRTY);	\
 	} while (0)
 
 #define SWP_TYPE_BITS 5
-#define __swp_type(x)		(((x).val >> _PAGE_BIT_SWAP_TYPE) \
-				& ((1UL << SWP_TYPE_BITS) - 1))
+#define SWP_TYPE_MASK		((1UL << SWP_TYPE_BITS) - 1)
+#define __swp_type(x)		((x).val & SWP_TYPE_MASK)
 #define __swp_offset(x)		(((x).val & PTE_RPN_MASK) >> PAGE_SHIFT)
 #define __swp_entry(type, offset)	((swp_entry_t) { \
-				((type) << _PAGE_BIT_SWAP_TYPE) \
-				| (((offset) << PAGE_SHIFT) & PTE_RPN_MASK)})
+				(type) | (((offset) << PAGE_SHIFT) & PTE_RPN_MASK)})
 /*
  * swp_entry_t must be independent of pte bits. We build a swp_entry_t from
  * swap type and offset we get from swap and convert that to pte to find a
@@ -774,7 +772,7 @@  static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 #define __swp_entry_to_pmd(x)	(pte_pmd(__swp_entry_to_pte(x)))
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
-#define _PAGE_SWP_SOFT_DIRTY   (1UL << (SWP_TYPE_BITS + _PAGE_BIT_SWAP_TYPE))
+#define _PAGE_SWP_SOFT_DIRTY	_PAGE_NON_IDEMPOTENT
 #else
 #define _PAGE_SWP_SOFT_DIRTY	0UL
 #endif /* CONFIG_MEM_SOFT_DIRTY */