[PATCH RFC 3/4] mm/x86: Use SWP_TYPE_BITS in 3-level swap macros

From: Peter Xu
Date: Thu Jul 28 2022 - 21:41:09 EST


Replace all the magic "5" with the macro.

Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
arch/x86/include/asm/pgtable-3level.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h
index e896ebef8c24..28421a887209 100644
--- a/arch/x86/include/asm/pgtable-3level.h
+++ b/arch/x86/include/asm/pgtable-3level.h
@@ -256,10 +256,10 @@ static inline pud_t native_pudp_get_and_clear(pud_t *pudp)
/* We always extract/encode the offset by shifting it all the way up, and then down again */
#define SWP_OFFSET_SHIFT (SWP_OFFSET_FIRST_BIT + SWP_TYPE_BITS)

-#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > 5)
-#define __swp_type(x) (((x).val) & 0x1f)
-#define __swp_offset(x) ((x).val >> 5)
-#define __swp_entry(type, offset) ((swp_entry_t){(type) | (offset) << 5})
+#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
+#define __swp_type(x) (((x).val) & ((1UL << SWP_TYPE_BITS) - 1))
+#define __swp_offset(x) ((x).val >> SWP_TYPE_BITS)
+#define __swp_entry(type, offset) ((swp_entry_t){(type) | (offset) << SWP_TYPE_BITS})

/*
* Normally, __swp_entry() converts from arch-independent swp_entry_t to
--
2.32.0