The kernel test bot reported[1] that using set_mask_bits on a u8 causes
the following issue on parisc:
hppa-linux-ld: drivers/phy/ti/phy-tusb1210.o: in function `tusb1210_probe':
>> (.text+0x2f4): undefined reference to `__cmpxchg_called_with_bad_pointer'
>> hppa-linux-ld: (.text+0x324): undefined reference to `__cmpxchg_called_with_bad_pointer'
hppa-linux-ld: (.text+0x354): undefined reference to `__cmpxchg_called_with_bad_pointer'
Add support for cmpxchg on u8 pointers.
[1] https://lore.kernel.org/patchwork/patch/1272617/#1468946
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Liam Beguin <[email protected]>
---
arch/parisc/include/asm/cmpxchg.h | 2 ++
arch/parisc/lib/bitops.c | 12 ++++++++++++
2 files changed, 14 insertions(+)
Hi,
This was reported by the kernel test bot on an architecture I can't
really test on. I was only able to make sure this builds, nothing more.
Should I also add __cmpxchg_u8 in the cmpxchg_local switch case?
There are one or two minor cleanups we can do around that patch, but
because of my limited testing options, I kept the changes to a minimum.
If there's interest, I can include these in follow up patches:
- update __cmpxchg_u32 to use u32 instead of unsigned int for
consistency
- add support for __cmpxchg_u16
Thanks,
Liam
diff --git a/arch/parisc/include/asm/cmpxchg.h b/arch/parisc/include/asm/cmpxchg.h
index ab5c215cf46c..068958575871 100644
--- a/arch/parisc/include/asm/cmpxchg.h
+++ b/arch/parisc/include/asm/cmpxchg.h
@@ -60,6 +60,7 @@ extern void __cmpxchg_called_with_bad_pointer(void);
extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old,
unsigned int new_);
extern u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new_);
+extern u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new_);
/* don't worry...optimizer will get rid of most of this */
static inline unsigned long
@@ -71,6 +72,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
#endif
case 4: return __cmpxchg_u32((unsigned int *)ptr,
(unsigned int)old, (unsigned int)new_);
+ case 1: return __cmpxchg_u8((u8 *)ptr, (u8)old, (u8)new_);
}
__cmpxchg_called_with_bad_pointer();
return old;
diff --git a/arch/parisc/lib/bitops.c b/arch/parisc/lib/bitops.c
index 70ffbcf889b8..2e4d1f05a926 100644
--- a/arch/parisc/lib/bitops.c
+++ b/arch/parisc/lib/bitops.c
@@ -79,3 +79,15 @@ unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsign
_atomic_spin_unlock_irqrestore(ptr, flags);
return (unsigned long)prev;
}
+
+u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new)
+{
+ unsigned long flags;
+ u8 prev;
+
+ _atomic_spin_lock_irqsave(ptr, flags);
+ if ((prev = *ptr) == old)
+ *ptr = new;
+ _atomic_spin_unlock_irqrestore(ptr, flags);
+ return prev;
+}
base-commit: 6cf7ccba29dcf39ab27630c383a3844078a6d5cd
--
2.27.0