[PATCH v2 8/8] powerpc/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE for book3s

David Hildenbrand
2022-03-29T16:50:28Z

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.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 21 +++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)

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)
{
/*
--
2.35.1