![]() | |||||||||||||
Messages in this thread |
On Wed, Nov 19, 2008 at 2:56 PM, Andrew Morton <akpm@linux-foundation.org> wrote: > On Tue, 18 Nov 2008 17:05:05 +0800 Bryan Wu <cooloney@kernel.org> wrote: > >> From: Graf Yang <graf.yang@analog.com> >> >> Blackfin dual core BF561 processor can support SMP like features. >> https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like >> >> In this patch, we provide SMP extend to Blackfin header files >> and machine common code >> >> >> ... >> >> +#define atomic_add_unless(v, a, u) \ >> +({ \ >> + int c, old; \ >> + c = atomic_read(v); \ >> + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ >> + c = old; \ >> + c != (u); \ >> +}) > > The macro references its args multiple times and will do weird or > inefficient things when called with expressions which have > side-effects, or which do slow things. > Right, I think we can replace them to inline functions >> >> ... >> >> +#include <asm/system.h> /* save_flags */ >> + >> +static inline void set_bit(int nr, volatile unsigned long *addr) >> { >> int *a = (int *)addr; >> int mask; >> @@ -57,21 +91,23 @@ static __inline__ void clear_bit(int nr, volatile unsigned long *addr) >> a += nr >> 5; >> mask = 1 << (nr & 0x1f); >> local_irq_save(flags); >> - *a &= ~mask; >> + *a |= mask; > > I think you just broke clear_bit(). Maybe I'm misreading the diff. > >> local_irq_restore(flags); >> } >> >> >> ... >> >> +#define smp_mb__before_clear_bit() barrier() >> +#define smp_mb__after_clear_bit() barrier() >> + >> +static inline void __set_bit(int nr, volatile unsigned long *addr) >> +{ >> + int *a = (int *)addr; >> + int mask; >> + >> + a += nr >> 5; >> + mask = 1 << (nr & 0x1f); >> + *a |= mask; >> +} >> + >> +static inline void __clear_bit(int nr, volatile unsigned long *addr) >> +{ >> + int *a = (int *)addr; >> + int mask; >> + >> + a += nr >> 5; >> + mask = 1 << (nr & 0x1f); >> + *a &= ~mask; >> +} >> + >> +static inline void __change_bit(int nr, volatile unsigned long *addr) >> +{ >> + int mask; >> + unsigned long *ADDR = (unsigned long *)addr; >> + >> + ADDR += nr >> 5; >> + mask = 1 << (nr & 31); >> + *ADDR ^= mask; >> +} > > I'm surprised there isn't any generic code which can be used for the above. > As Nick said, include/asm-generic/bitops/non-atomic.h is the generic code. We will try it. >> >> ... >> > > Gad what a lot of code. I don't think I have time to read it all, sorry. > Thanks a lot for the review, I will forward this patchset to linux-arch. -Bryan | ||||||||||||
| Last update: 2008-11-19 08:45 [from the cache] ©2003-2008 | |||||||||||||