powerpc/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE for book3s

Right now, the last 5 bits (0x1f) of the swap entry are used for the type
and the bit before that (0x20) is used for _PAGE_SWP_SOFT_DIRTY.  We
cannot use 0x40, as that collides with _RPAGE_RSV1 -- contained in
_PAGE_HPTEFLAGS.  The next candidate would be _RPAGE_SW3 (0x200) -- which
is used for _PAGE_SOFT_DIRTY for !swp ptes.

So let's just use _PAGE_SOFT_DIRTY for _PAGE_SWP_SOFT_DIRTY (to make it
easier to grasp) and use 0x20 now for _PAGE_SWP_EXCLUSIVE.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Don Dutile <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: John Hubbard <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Liang Zhang <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Oded Gabbay <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Pedro Demarchi Gomes <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 20 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 8e98375d5c4a..eecff2036869 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -752,6 +752,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 	 */							\
 	BUILD_BUG_ON(_PAGE_HPTEFLAGS & SWP_TYPE_MASK); \
 	BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_SOFT_DIRTY);	\
+	BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_EXCLUSIVE);	\
 	} while (0)
 
 #define SWP_TYPE_BITS 5
@@ -772,11 +773,13 @@ 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	_PAGE_NON_IDEMPOTENT
+#define _PAGE_SWP_SOFT_DIRTY	_PAGE_SOFT_DIRTY
 #else
 #define _PAGE_SWP_SOFT_DIRTY	0UL
 #endif /* CONFIG_MEM_SOFT_DIRTY */
 
+#define _PAGE_SWP_EXCLUSIVE	_PAGE_NON_IDEMPOTENT
+
 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
 static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
 {
@@ -794,6 +797,22 @@ static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
 }
 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
 
+#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE
+static inline pte_t pte_swp_mkexclusive(pte_t pte)
+{
+	return __pte_raw(pte_raw(pte) | cpu_to_be64(_PAGE_SWP_EXCLUSIVE));
+}
+
+static inline int pte_swp_exclusive(pte_t pte)
+{
+	return !!(pte_raw(pte) & cpu_to_be64(_PAGE_SWP_EXCLUSIVE));
+}
+
+static inline pte_t pte_swp_clear_exclusive(pte_t pte)
+{
+	return __pte_raw(pte_raw(pte) & cpu_to_be64(~_PAGE_SWP_EXCLUSIVE));
+}
+
 static inline bool check_pte_access(unsigned long access, unsigned long ptev)
 {
 	/*