From: Peter Zijlstra <peterz@infradead.org>
To: Will Deacon <will.deacon@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Victor Kaplansky <VICTORK@il.ibm.com>,
Oleg Nesterov <oleg@redhat.com>,
Anton Blanchard <anton@samba.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux PPC dev <linuxppc-dev@ozlabs.org>,
Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
Michael Ellerman <michael@ellerman.id.au>,
Michael Neuling <mikey@neuling.org>,
Russell King <linux@arm.linux.org.uk>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Tony Luck <tony.luck@intel.com>
Subject: Re: [RFC] arch: Introduce new TSO memory barrier smp_tmb()
Date: Thu, 7 Nov 2013 14:36:25 +0100 [thread overview]
Message-ID: <20131107133625.GU10651@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20131107111741.GD13139@mudshark.cambridge.arm.com>
On Thu, Nov 07, 2013 at 11:17:41AM +0000, Will Deacon wrote:
> 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?
oops..
> > +#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>
Thanks, I did that split-up I talked about yesterday, I was going to
compile them for all archs I have a compiler for before posting again.
---
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -62,11 +62,11 @@ do { \
compiletime_assert_atomic_type(*p); \
switch (sizeof(*p)) { \
case 4: \
- asm volatile ("stlr %w1, [%0]" \
+ asm volatile ("stlr %w1, %0" \
: "=Q" (*p) : "r" (v) : "memory"); \
break; \
case 8: \
- asm volatile ("stlr %1, [%0]" \
+ asm volatile ("stlr %1, %0" \
: "=Q" (*p) : "r" (v) : "memory"); \
break; \
} \
@@ -78,17 +78,19 @@ do { \
compiletime_assert_atomic_type(*p); \
switch (sizeof(*p)) { \
case 4: \
- asm volatile ("ldar %w0, [%1]" \
+ asm volatile ("ldar %w0, %1" \
: "=r" (___p1) : "Q" (*p) : "memory"); \
break; \
case 8: \
- asm volatile ("ldar %0, [%1]" \
+ asm volatile ("ldar %0, %1" \
: "=r" (___p1) : "Q" (*p) : "memory"); \
break; \
} \
___p1; \
})
+#endif
+
#define read_barrier_depends() do { } while(0)
#define smp_read_barrier_depends() do { } while(0)
next prev parent reply other threads:[~2013-11-07 13:37 UTC|newest]
Thread overview: 117+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-22 23:54 perf events ring buffer memory barrier on powerpc Michael Neuling
2013-10-23 7:39 ` Victor Kaplansky
2013-10-23 14:19 ` Frederic Weisbecker
2013-10-23 14:25 ` Frederic Weisbecker
2013-10-25 17:37 ` Peter Zijlstra
2013-10-25 20:31 ` Michael Neuling
2013-10-27 9:00 ` Victor Kaplansky
2013-10-28 9:22 ` Peter Zijlstra
2013-10-28 10:02 ` Frederic Weisbecker
2013-10-28 12:38 ` Victor Kaplansky
2013-10-28 13:26 ` Peter Zijlstra
2013-10-28 16:34 ` Paul E. McKenney
2013-10-28 20:17 ` Oleg Nesterov
2013-10-28 20:58 ` Victor Kaplansky
2013-10-29 10:21 ` Peter Zijlstra
2013-10-29 10:30 ` Peter Zijlstra
2013-10-29 10:35 ` Peter Zijlstra
2013-10-29 20:15 ` Oleg Nesterov
2013-10-29 19:27 ` Vince Weaver
2013-10-30 10:42 ` Peter Zijlstra
2013-10-30 11:48 ` James Hogan
2013-10-30 12:48 ` Peter Zijlstra
2013-11-06 13:19 ` [tip:perf/core] tools/perf: Add required memory barriers tip-bot for Peter Zijlstra
2013-11-06 13:50 ` Vince Weaver
2013-11-06 14:00 ` Peter Zijlstra
2013-11-06 14:28 ` Peter Zijlstra
2013-11-06 14:55 ` Vince Weaver
2013-11-06 15:10 ` Peter Zijlstra
2013-11-06 15:23 ` Peter Zijlstra
2013-11-06 14:44 ` Peter Zijlstra
2013-11-06 16:07 ` Peter Zijlstra
2013-11-06 17:31 ` Vince Weaver
2013-11-06 18:24 ` Peter Zijlstra
2013-11-07 8:21 ` Ingo Molnar
2013-11-07 14:27 ` Vince Weaver
2013-11-07 15:55 ` Ingo Molnar
2013-11-11 16:24 ` Peter Zijlstra
2013-11-11 21:10 ` Ingo Molnar
2013-10-29 21:23 ` perf events ring buffer memory barrier on powerpc Michael Neuling
2013-10-30 9:27 ` Paul E. McKenney
2013-10-30 11:25 ` Peter Zijlstra
2013-10-30 14:52 ` Victor Kaplansky
2013-10-30 15:39 ` Peter Zijlstra
2013-10-30 17:14 ` Victor Kaplansky
2013-10-30 17:44 ` Peter Zijlstra
2013-10-31 6:16 ` Paul E. McKenney
2013-11-01 13:12 ` Victor Kaplansky
2013-11-02 16:36 ` Paul E. McKenney
2013-11-02 17:26 ` Paul E. McKenney
2013-10-31 6:40 ` Paul E. McKenney
2013-11-01 14:25 ` Victor Kaplansky
2013-11-02 17:28 ` Paul E. McKenney
2013-11-01 14:56 ` Peter Zijlstra
2013-11-02 17:32 ` Paul E. McKenney
2013-11-03 14:40 ` Paul E. McKenney
2013-11-03 15:17 ` [RFC] arch: Introduce new TSO memory barrier smp_tmb() Peter Zijlstra
2013-11-03 18:08 ` Linus Torvalds
2013-11-03 20:01 ` Peter Zijlstra
2013-11-03 22:42 ` Paul E. McKenney
2013-11-03 23:34 ` Linus Torvalds
2013-11-04 10:51 ` Paul E. McKenney
2013-11-04 11:22 ` Peter Zijlstra
2013-11-04 16:27 ` Paul E. McKenney
2013-11-04 16:48 ` Peter Zijlstra
2013-11-04 19:11 ` Peter Zijlstra
2013-11-04 19:18 ` Peter Zijlstra
2013-11-04 20:54 ` Paul E. McKenney
2013-11-04 20:53 ` Paul E. McKenney
2013-11-05 14:05 ` Will Deacon
2013-11-05 14:49 ` Paul E. McKenney
2013-11-05 18:49 ` Peter Zijlstra
2013-11-06 11:00 ` Will Deacon
2013-11-06 12:39 ` Peter Zijlstra
2013-11-06 12:51 ` Geert Uytterhoeven
2013-11-06 13:57 ` Peter Zijlstra
2013-11-06 18:48 ` Paul E. McKenney
2013-11-06 19:42 ` Peter Zijlstra
2013-11-07 11:17 ` Will Deacon
2013-11-07 13:36 ` Peter Zijlstra [this message]
2013-11-07 23:50 ` Mathieu Desnoyers
2013-11-04 11:05 ` Will Deacon
2013-11-04 16:34 ` Paul E. McKenney
2013-11-03 20:59 ` Benjamin Herrenschmidt
2013-11-03 22:43 ` Paul E. McKenney
2013-11-03 17:07 ` perf events ring buffer memory barrier on powerpc Will Deacon
2013-11-03 22:47 ` Paul E. McKenney
2013-11-04 9:57 ` Will Deacon
2013-11-04 10:52 ` Paul E. McKenney
2013-11-01 16:11 ` Peter Zijlstra
2013-11-02 17:46 ` Paul E. McKenney
2013-11-01 16:18 ` Peter Zijlstra
2013-11-02 17:49 ` Paul E. McKenney
2013-10-30 13:28 ` Victor Kaplansky
2013-10-30 15:51 ` Peter Zijlstra
2013-10-30 18:29 ` Peter Zijlstra
2013-10-30 19:11 ` Peter Zijlstra
2013-10-31 4:33 ` Paul E. McKenney
2013-10-31 4:32 ` Paul E. McKenney
2013-10-31 9:04 ` Peter Zijlstra
2013-10-31 15:07 ` Paul E. McKenney
2013-10-31 15:19 ` Peter Zijlstra
2013-11-01 9:28 ` Paul E. McKenney
2013-11-01 10:30 ` Peter Zijlstra
2013-11-02 15:20 ` Paul E. McKenney
2013-11-04 9:07 ` Peter Zijlstra
2013-11-04 10:00 ` Paul E. McKenney
2013-10-31 9:59 ` Victor Kaplansky
2013-10-31 12:28 ` David Laight
2013-10-31 12:55 ` Victor Kaplansky
2013-10-31 15:25 ` Paul E. McKenney
2013-11-01 16:06 ` Victor Kaplansky
2013-11-01 16:25 ` David Laight
2013-11-01 16:30 ` Victor Kaplansky
2013-11-03 20:57 ` Benjamin Herrenschmidt
2013-11-02 15:46 ` Paul E. McKenney
2013-10-28 19:09 ` Oleg Nesterov
2013-10-29 14:06 ` [tip:perf/urgent] perf: Fix perf ring buffer memory ordering tip-bot for Peter Zijlstra
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