Messages in this thread | | | Subject | Re: [PATCH 2/5] Blackfin arch: SMP supporting patchset: Blackfin header files and machine common code | From | gyang <> | Date | Wed, 19 Nov 2008 15:52:50 +0800 |
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在 2008-11-18二的 22:56 -0800,Andrew Morton写道: > 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. OK, We have corrected it on our own tree. > > > 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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