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 <lkp@xxxxxxxxx> Signed-off-by: Liam Beguin <liambeguin@xxxxxxxxx> --- 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
