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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. >> ...>> +#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. >> ...> Gad what a lot of code. I don't think I have time to read it all, sorry. | ||||||||||||
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