[PATCH 4/8] sparc32: add __cmpxchg_u{8,16}() and teach __cmpxchg() to handle those sizes

From: Al Viro
Date: Tue Apr 02 2024 - 00:27:43 EST


trivial now

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
arch/sparc/include/asm/cmpxchg_32.h | 7 ++++++-
arch/sparc/lib/atomic32.c | 4 ++++
2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/sparc/include/asm/cmpxchg_32.h b/arch/sparc/include/asm/cmpxchg_32.h
index 86254c366477..1324984de36a 100644
--- a/arch/sparc/include/asm/cmpxchg_32.h
+++ b/arch/sparc/include/asm/cmpxchg_32.h
@@ -38,7 +38,8 @@ static __always_inline unsigned long __arch_xchg(unsigned long x, __volatile__ v

/* bug catcher for when unsupported size is used - won't link */
void __cmpxchg_called_with_bad_pointer(void);
-/* we only need to support cmpxchg of a u32 on sparc */
+u8 __cmpxchg_u8(volatile u8 *m, u8 old, u8 new_);
+u16 __cmpxchg_u16(volatile u16 *m, u16 old, u16 new_);
u32 __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);

/* don't worry...optimizer will get rid of most of this */
@@ -46,6 +47,10 @@ static inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
{
switch (size) {
+ case 1:
+ return __cmpxchg_u8((u8 *)ptr, (u8)old, (u8)new_);
+ case 2:
+ return __cmpxchg_u16((u16 *)ptr, (u16)old, (u16)new_);
case 4:
return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_);
default:
diff --git a/arch/sparc/lib/atomic32.c b/arch/sparc/lib/atomic32.c
index 0d215a772428..8ae880ebf07a 100644
--- a/arch/sparc/lib/atomic32.c
+++ b/arch/sparc/lib/atomic32.c
@@ -173,8 +173,12 @@ EXPORT_SYMBOL(sp32___change_bit);
return prev; \
}

+CMPXCHG(u8)
+CMPXCHG(u16)
CMPXCHG(u32)
CMPXCHG(u64)
+EXPORT_SYMBOL(__cmpxchg_u8);
+EXPORT_SYMBOL(__cmpxchg_u16);
EXPORT_SYMBOL(__cmpxchg_u32);
EXPORT_SYMBOL(__cmpxchg_u64);

--
2.39.2