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mm/x86: Use SWP_TYPE_BITS in 3-level swap macros

PATCH In review Peter Xu 2 participants 2 messages Aug 3, 2022

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Memory management x86
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Peter Xu

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#0 lore raw

PATCH 1/1 mm/x86: Use SWP_TYPE_BITS in 3-level swap macros

Replace all the magic "5" with the macro.

Signed-off-by Peter Xu <[email protected]>
---
 arch/x86/include/asm/pgtable-3level.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
arch/x86/include/asm/pgtable-3level.h +4 -4
index e896ebef8c24..28421a887209 100644
@@ -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
Signature · 1 line
2.32.0
Reviewed-by on v1 1/1
#1 lore raw
Quoted 16 lines · Peter Xu

Replace all the magic "5" with the macro.

Signed-off-by Peter Xu <[email protected]>
---
 arch/x86/include/asm/pgtable-3level.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
arch/x86/include/asm/pgtable-3level.h +0 -1
index e896ebef8c24..28421a887209 100644
@@ -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)

arch/x86/include/asm/pgtable-3level.h static inline pud_t native_pudp_get_and_clear(pud_t *pudp) · line 265

Quoted 10 lines
arch/x86/include/asm/pgtable-3level.h +4 -3
-#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
Reviewed-by David Hildenbrand <[email protected]>
Signature · 3 lines
Thanks,

David / dhildenb