Re: [PATCH] powerpc: add the missing required isync for the coherent icache flush

2013-08-21 Thread Kevin Hao
On Wed, Aug 21, 2013 at 07:28:54AM +1000, Benjamin Herrenschmidt wrote: > On Tue, 2013-08-20 at 20:16 +0800, Kevin Hao wrote: > > > Dummy question: What does the ifetch buffers mean? The instruction fetch > > pipeline or instruction dispatch pipeline? Shouldn't all the prefetched > > instructions

Re: [PATCH] powerpc: add the missing required isync for the coherent icache flush

2013-08-20 Thread Benjamin Herrenschmidt
On Tue, 2013-08-20 at 20:16 +0800, Kevin Hao wrote: > Dummy question: What does the ifetch buffers mean? The instruction fetch > pipeline or instruction dispatch pipeline? Shouldn't all the prefetched > instructions in these buffers be discarded by isync? Architecturally isync doesn't have to tos

Re: [PATCH] powerpc: add the missing required isync for the coherent icache flush

2013-08-20 Thread Kevin Hao
On Mon, Aug 19, 2013 at 10:45:35PM +1000, Benjamin Herrenschmidt wrote: > On Mon, 2013-08-19 at 19:50 +0800, Kevin Hao wrote: > > On Mon, Aug 19, 2013 at 01:37:17PM +1000, Benjamin Herrenschmidt wrote: > > > On Mon, 2013-08-19 at 13:36 +1000, Benjamin Herrenschmidt wrote: > > > > > > > The semanti

Re: [PATCH] powerpc: add the missing required isync for the coherent icache flush

2013-08-19 Thread Benjamin Herrenschmidt
On Mon, 2013-08-19 at 19:50 +0800, Kevin Hao wrote: > On Mon, Aug 19, 2013 at 01:37:17PM +1000, Benjamin Herrenschmidt wrote: > > On Mon, 2013-08-19 at 13:36 +1000, Benjamin Herrenschmidt wrote: > > > > > The semantic of this function is to make data executable. Even if the > > > implementation ha

Re: [PATCH] powerpc: add the missing required isync for the coherent icache flush

2013-08-19 Thread Kevin Hao
On Mon, Aug 19, 2013 at 01:37:17PM +1000, Benjamin Herrenschmidt wrote: > On Mon, 2013-08-19 at 13:36 +1000, Benjamin Herrenschmidt wrote: > > > The semantic of this function is to make data executable. Even if the > > implementation has a snooping icache, it *still* needs to make sure > > prefetc

Re: [PATCH] powerpc: add the missing required isync for the coherent icache flush

2013-08-18 Thread Benjamin Herrenschmidt
On Mon, 2013-08-19 at 13:36 +1000, Benjamin Herrenschmidt wrote: > The semantic of this function is to make data executable. Even if the > implementation has a snooping icache, it *still* needs to make sure > prefetched code is tossed out of the pipeline which is what isync > should provide. > >

Re: [PATCH] powerpc: add the missing required isync for the coherent icache flush

2013-08-18 Thread Benjamin Herrenschmidt
On Mon, 2013-08-19 at 03:24 +, Wang Dongsheng-B40534 wrote: > > > -Original Message- > > From: Linuxppc-dev [mailto:linuxppc-dev- > > bounces+b40534=freescale@lists.ozlabs.org] On Behalf Of Kevin Hao > > Sent: Thursday, August 15, 2013 7:56 PM > > To: Benjamin Herrenschmidt > > Cc:

RE: [PATCH] powerpc: add the missing required isync for the coherent icache flush

2013-08-18 Thread Wang Dongsheng-B40534
> -Original Message- > From: Linuxppc-dev [mailto:linuxppc-dev- > bounces+b40534=freescale@lists.ozlabs.org] On Behalf Of Kevin Hao > Sent: Thursday, August 15, 2013 7:56 PM > To: Benjamin Herrenschmidt > Cc: linuxppc > Subject: [PATCH] powerpc: add the missing required isync for the