Messages in this thread | | | Date | Wed, 19 Nov 2008 16:20:07 +0800 | From | "Bryan Wu" <> | Subject | Re: [PATCH 2/5] Blackfin arch: SMP supporting patchset: Blackfin header files and machine common code |
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On Wed, Nov 19, 2008 at 3:52 PM, gyang <graf.yang@analog.com> wrote: > > 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.
Both the code and the patch are all right. Because the mess from diff, we all misread it.
-Bryan
>> >> > 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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