diff options
| author | David Hildenbrand <david@redhat.com> | 2023-01-13 18:10:08 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-02 22:33:07 -0800 |
| commit | ad3150f11b099321331f2f74d008e86ab2a04c7a (patch) | |
| tree | 82d4499ac0639b7b77f2eb8c301907810eea418f /arch/loongarch/include/asm/pgtable-bits.h | |
| parent | 3151cc26565ea864c51a78900101ad68b864f405 (diff) | |
loongarch/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the
type. Generic MM currently only uses 5 bits for the type
(MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused.
While at it, also mask the type in mk_swap_pte().
Note that this bit does not conflict with swap PMDs and could also be used
in swap PMD context later.
Link: https://lkml.kernel.org/r/20230113171026.582290-9-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/loongarch/include/asm/pgtable-bits.h')
| -rw-r--r-- | arch/loongarch/include/asm/pgtable-bits.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/pgtable-bits.h b/arch/loongarch/include/asm/pgtable-bits.h index 3d1e0a69975a..8b98d22a145b 100644 --- a/arch/loongarch/include/asm/pgtable-bits.h +++ b/arch/loongarch/include/asm/pgtable-bits.h @@ -20,6 +20,7 @@ #define _PAGE_SPECIAL_SHIFT 11 #define _PAGE_HGLOBAL_SHIFT 12 /* HGlobal is a PMD bit */ #define _PAGE_PFN_SHIFT 12 +#define _PAGE_SWP_EXCLUSIVE_SHIFT 23 #define _PAGE_PFN_END_SHIFT 48 #define _PAGE_NO_READ_SHIFT 61 #define _PAGE_NO_EXEC_SHIFT 62 @@ -33,6 +34,9 @@ #define _PAGE_PROTNONE (_ULCAST_(1) << _PAGE_PROTNONE_SHIFT) #define _PAGE_SPECIAL (_ULCAST_(1) << _PAGE_SPECIAL_SHIFT) +/* We borrow bit 23 to store the exclusive marker in swap PTEs. */ +#define _PAGE_SWP_EXCLUSIVE (_ULCAST_(1) << _PAGE_SWP_EXCLUSIVE_SHIFT) + /* Used by TLB hardware (placed in EntryLo*) */ #define _PAGE_VALID (_ULCAST_(1) << _PAGE_VALID_SHIFT) #define _PAGE_DIRTY (_ULCAST_(1) << _PAGE_DIRTY_SHIFT) |