| Message ID | 5256121A.9030504@asianux.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Oct 10, 2013 at 03:34:02AM +0100, Chen Gang wrote: > In current kernel wide source, for arm, only s390 scsi drivers use > atomic_clear_mask(), now, s390 itself need use 'unsigned int' and > 'atomic_t', so need match s390's atomic_clear_mask(). > > > Signed-off-by: Chen Gang <gang.chen@asianux.com> > --- > arch/arm/include/asm/atomic.h | 13 +++++++------ > 1 files changed, 7 insertions(+), 6 deletions(-) > > diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h > index da1c77d..0832a7f 100644 > --- a/arch/arm/include/asm/atomic.h > +++ b/arch/arm/include/asm/atomic.h > @@ -134,9 +134,10 @@ static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new) > return oldval; > } > > -static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) > +static inline void atomic_clear_mask(unsigned int mask, atomic_t *ptr) > { > - unsigned long tmp, tmp2; > + unsigned int tmp; I reckon this should be int (the mask parameter is unsigned, but atomic_t.counter is signed). > + unsigned long tmp2; > > __asm__ __volatile__("@ atomic_clear_mask\n" > "1: ldrex %0, [%3]\n" > @@ -144,8 +145,8 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) > " strex %1, %0, [%3]\n" > " teq %1, #0\n" > " bne 1b" > - : "=&r" (tmp), "=&r" (tmp2), "+Qo" (*addr) > - : "r" (addr), "Ir" (mask) > + : "=&r" (tmp), "=&r" (tmp2), "+Qo" (ptr->counter) > + : "r" (&ptr->counter), "Ir" (mask) > : "cc"); > } > > @@ -197,12 +198,12 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) > return ret; > } > > -static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) > +static inline void atomic_clear_mask(unsigned int mask, atomic_t *v) > { > unsigned long flags; > > raw_local_irq_save(flags); > - *addr &= ~mask; > + v->counter &= ~mask; > raw_local_irq_restore(flags); > } This is now identical to asm-generic/atomic.h. I wonder whether we could just #include that file for the ARMv6 case? You'd need to check the differences carefully. Finally, I still question the need for the clear_mask function anyway. We don't implement set_mask, and these functions are only used by either other arch code or in drivers that don't work on ARM anyway. Will
On 10/10/2013 05:58 PM, Will Deacon wrote: > On Thu, Oct 10, 2013 at 03:34:02AM +0100, Chen Gang wrote: >> In current kernel wide source, for arm, only s390 scsi drivers use >> atomic_clear_mask(), now, s390 itself need use 'unsigned int' and >> 'atomic_t', so need match s390's atomic_clear_mask(). >> >> >> Signed-off-by: Chen Gang <gang.chen@asianux.com> >> --- >> arch/arm/include/asm/atomic.h | 13 +++++++------ >> 1 files changed, 7 insertions(+), 6 deletions(-) >> >> diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h >> index da1c77d..0832a7f 100644 >> --- a/arch/arm/include/asm/atomic.h >> +++ b/arch/arm/include/asm/atomic.h >> @@ -134,9 +134,10 @@ static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new) >> return oldval; >> } >> >> -static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) >> +static inline void atomic_clear_mask(unsigned int mask, atomic_t *ptr) >> { >> - unsigned long tmp, tmp2; >> + unsigned int tmp; > > I reckon this should be int (the mask parameter is unsigned, but > atomic_t.counter is signed). For 'ldrex' and 'strex' (loading/storing instruction), it is really better to match 'atomic_t.counter', but for 'bic' (operating instruction), it is better to match 'mask'. In my opinion, for signed/unsigned, 'operating' has higher priority than 'loading/storing' (especially for *mask functions, by default, suggest using unsigned). Commonly, for loading/storing (e.g. 'ldrex', 'strex'), must be sure of bits wide (signed/unsigned will not cause real issues), but for operating, signed/unsigned may cause real issues. > >> + unsigned long tmp2; >> >> __asm__ __volatile__("@ atomic_clear_mask\n" >> "1: ldrex %0, [%3]\n" >> @@ -144,8 +145,8 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) >> " strex %1, %0, [%3]\n" >> " teq %1, #0\n" >> " bne 1b" >> - : "=&r" (tmp), "=&r" (tmp2), "+Qo" (*addr) >> - : "r" (addr), "Ir" (mask) >> + : "=&r" (tmp), "=&r" (tmp2), "+Qo" (ptr->counter) >> + : "r" (&ptr->counter), "Ir" (mask) >> : "cc"); >> } >> >> @@ -197,12 +198,12 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) >> return ret; >> } >> >> -static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) >> +static inline void atomic_clear_mask(unsigned int mask, atomic_t *v) >> { >> unsigned long flags; >> >> raw_local_irq_save(flags); >> - *addr &= ~mask; >> + v->counter &= ~mask; >> raw_local_irq_restore(flags); >> } > > This is now identical to asm-generic/atomic.h. I wonder whether we could > just #include that file for the ARMv6 case? You'd need to check the > differences carefully. > If most of functions for ARMv6 case can use "asm-generic/atomic.h", your idea sounds good to me, although we don't need 'atomic_set_mask' (it is inconsistent with 'atomic_clear_mask' in "asm-generic/atomic.h"). > Finally, I still question the need for the clear_mask function anyway. We > don't implement set_mask, and these functions are only used by either other > arch code or in drivers that don't work on ARM anyway. > Hmm... can we remove atomic_*_mask() for both arm and arm64? It seems before get a conclusion, it is necessary to let arm and arm64 pass 'allmodconfig' firstly (and then try to remove these functions to see the compiling result). I will/should try 'allmodconfig' for them, but excuse me, it needs waiting (I am just trying 'arc' architecture with 'allmodconfig', and already delayed, because I have no enough time resources on it :-( ). > Will > > Thanks.
diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h index da1c77d..0832a7f 100644 --- a/arch/arm/include/asm/atomic.h +++ b/arch/arm/include/asm/atomic.h @@ -134,9 +134,10 @@ static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new) return oldval; } -static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) +static inline void atomic_clear_mask(unsigned int mask, atomic_t *ptr) { - unsigned long tmp, tmp2; + unsigned int tmp; + unsigned long tmp2; __asm__ __volatile__("@ atomic_clear_mask\n" "1: ldrex %0, [%3]\n" @@ -144,8 +145,8 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) " strex %1, %0, [%3]\n" " teq %1, #0\n" " bne 1b" - : "=&r" (tmp), "=&r" (tmp2), "+Qo" (*addr) - : "r" (addr), "Ir" (mask) + : "=&r" (tmp), "=&r" (tmp2), "+Qo" (ptr->counter) + : "r" (&ptr->counter), "Ir" (mask) : "cc"); } @@ -197,12 +198,12 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } -static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) +static inline void atomic_clear_mask(unsigned int mask, atomic_t *v) { unsigned long flags; raw_local_irq_save(flags); - *addr &= ~mask; + v->counter &= ~mask; raw_local_irq_restore(flags); }
In current kernel wide source, for arm, only s390 scsi drivers use atomic_clear_mask(), now, s390 itself need use 'unsigned int' and 'atomic_t', so need match s390's atomic_clear_mask(). Signed-off-by: Chen Gang <gang.chen@asianux.com> --- arch/arm/include/asm/atomic.h | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-)