Re: [PATCH] ARM: Weaker memory barriers

2014-03-12 Thread Will Deacon
On Tue, Mar 11, 2014 at 09:12:53PM +, John Carr wrote: > Will Deacon wrote: > > On Tue, Mar 11, 2014 at 02:54:18AM +, John Carr wrote: > > > A comment in arm/sync.md notes "We should consider issuing a inner > > > shareability zone barrier here instead." Here is my first attempt > > > at

Re: [PATCH] ARM: Weaker memory barriers

2014-03-11 Thread John Carr
Will Deacon wrote: > > Hi John, > > On Tue, Mar 11, 2014 at 02:54:18AM +, John Carr wrote: > > A comment in arm/sync.md notes "We should consider issuing a inner > > shareability zone barrier here instead." Here is my first attempt > > at a patch to emit weaker memory barriers. Three ins

Re: [PATCH] ARM: Weaker memory barriers

2014-03-11 Thread Will Deacon
Hi John, On Tue, Mar 11, 2014 at 02:54:18AM +, John Carr wrote: > A comment in arm/sync.md notes "We should consider issuing a inner > shareability zone barrier here instead." Here is my first attempt > at a patch to emit weaker memory barriers. Three instructions seem > to be relevant for

[PATCH] ARM: Weaker memory barriers

2014-03-10 Thread John Carr
A comment in arm/sync.md notes "We should consider issuing a inner shareability zone barrier here instead." Here is my first attempt at a patch to emit weaker memory barriers. Three instructions seem to be relevant for user mode code on my Cortex A9 Linux box: dmb ishst, dmb ish, dmb sy I belie