Messages in this thread Patch in this message |  | | Date | Thu, 7 Nov 2013 11:17:41 +0000 | From | Will Deacon <> | Subject | Re: [RFC] arch: Introduce new TSO memory barrier smp_tmb() |
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Hi Peter,
Couple of minor fixes on the arm64 side...
On Wed, Nov 06, 2013 at 01:57:36PM +0000, Peter Zijlstra wrote: > --- a/arch/arm64/include/asm/barrier.h > +++ b/arch/arm64/include/asm/barrier.h > @@ -35,11 +35,59 @@ > #define smp_mb() barrier() > #define smp_rmb() barrier() > #define smp_wmb() barrier() > + > +#define smp_store_release(p, v) \ > +do { \ > + compiletime_assert_atomic_type(*p); \ > + smp_mb(); \ > + ACCESS_ONCE(*p) = (v); \ > +} while (0) > + > +#define smp_load_acquire(p) \ > +({ \ > + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ > + compiletime_assert_atomic_type(*p); \ > + smp_mb(); \ > + ___p1; \ > +}) > + > #else > + > #define smp_mb() asm volatile("dmb ish" : : : "memory") > #define smp_rmb() asm volatile("dmb ishld" : : : "memory") > #define smp_wmb() asm volatile("dmb ishst" : : : "memory") > -#endif
Why are you getting rid of this #endif?
> +#define smp_store_release(p, v) \ > +do { \ > + compiletime_assert_atomic_type(*p); \ > + switch (sizeof(*p)) { \ > + case 4: \ > + asm volatile ("stlr %w1, [%0]" \ > + : "=Q" (*p) : "r" (v) : "memory"); \ > + break; \ > + case 8: \ > + asm volatile ("stlr %1, [%0]" \ > + : "=Q" (*p) : "r" (v) : "memory"); \ > + break; \ > + } \ > +} while (0) > + > +#define smp_load_acquire(p) \ > +({ \ > + typeof(*p) ___p1; \ > + compiletime_assert_atomic_type(*p); \ > + switch (sizeof(*p)) { \ > + case 4: \ > + asm volatile ("ldar %w0, [%1]" \ > + : "=r" (___p1) : "Q" (*p) : "memory"); \ > + break; \ > + case 8: \ > + asm volatile ("ldar %0, [%1]" \ > + : "=r" (___p1) : "Q" (*p) : "memory"); \ > + break; \ > + } \ > + ___p1; \ > +})
You don't need the square brackets when using the "Q" constraint (otherwise it will expand to something like [[x0]], which gas won't accept).
With those changes, for the general idea and arm/arm64 parts:
Acked-by: Will Deacon <will.deacon@arm.com>
Will
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