From: "K.Prasad" <prasad@linux.vnet.ibm.com>
To: Benjamin Herrenschmidt <benh@au1.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>,
shaggy@linux.vnet.ibm.com,
Frederic Weisbecker <fweisbec@gmail.com>,
David Gibson <dwg@au1.ibm.com>,
linuxppc-dev@ozlabs.org, Paul Mackerras <paulus@samba.org>,
Alan Stern <stern@rowland.harvard.edu>,
Roland McGrath <roland@redhat.com>
Subject: Re: [RFC Patch 1/2] PPC64-HWBKPT: Disable interrupts for data breakpoint exceptions
Date: Tue, 30 Mar 2010 15:49:08 +0530 [thread overview]
Message-ID: <20100330101908.GC14734@in.ibm.com> (raw)
In-Reply-To: <1269927145.7101.48.camel@pasglop>
On Tue, Mar 30, 2010 at 04:32:25PM +1100, Benjamin Herrenschmidt wrote:
> On Tue, 2010-03-30 at 16:24 +1100, Paul Mackerras wrote:
> > On Tue, Mar 23, 2010 at 07:37:02PM +0530, K.Prasad wrote:
> >
> > > Index: linux-2.6.ppc64_test/arch/powerpc/kernel/exceptions-64s.S
> > > ===================================================================
> > > --- linux-2.6.ppc64_test.orig/arch/powerpc/kernel/exceptions-64s.S
> > > +++ linux-2.6.ppc64_test/arch/powerpc/kernel/exceptions-64s.S
> > > @@ -735,6 +735,9 @@ _STATIC(do_hash_page)
> > > std r3,_DAR(r1)
> > > std r4,_DSISR(r1)
> > >
> > > + andis. r0,r4,0x0040 /* Data Address Breakpoint match? */
> >
> > Minor comment: why not DSISR_DABRMATCH@h instead of 0x0040?
> >
> > > + bne- handle_dabr_fault
> > > +
> > > andis. r0,r4,0xa450 /* weird error? */
> > > bne- handle_page_fault /* if not, try to insert a HPTE */
> > > BEGIN_FTR_SECTION
> > > @@ -823,6 +826,15 @@ END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISER
> > > bl .raw_local_irq_restore
> > > b 11f
>
> I would move your new test to the "weird error" case (ie, after the bne-
> handle_page_fault) to avoid hitting the fast path.
>
Done that...so basically the branch to handle_page_fault will happen
only if 0xa410 matches.
The changes can be seen here: linuxppc-dev: message-id:
20100330095925.GB14403@in.ibm.com.
Thanks,
K.Prasad
next prev parent reply other threads:[~2010-03-30 10:19 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20100323140008.954823303@pr>
2010-03-23 14:07 ` [RFC Patch 1/2] PPC64-HWBKPT: Disable interrupts for data breakpoint exceptions K.Prasad
2010-03-30 5:24 ` Paul Mackerras
2010-03-30 5:32 ` Benjamin Herrenschmidt
2010-03-30 10:19 ` K.Prasad [this message]
2010-03-30 10:17 ` K.Prasad
2010-03-23 14:07 ` [RFC Patch 2/2] PPC64-HWBKPT: Implement hw-breakpoints for PPC64 K.Prasad
2010-03-26 21:11 ` Dave Kleikamp
2010-03-29 11:31 ` K.Prasad
2010-03-29 19:53 ` Dave Kleikamp
2010-03-30 10:12 ` K.Prasad
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100330101908.GC14734@in.ibm.com \
--to=prasad@linux.vnet.ibm.com \
--cc=benh@au1.ibm.com \
--cc=dwg@au1.ibm.com \
--cc=fweisbec@gmail.com \
--cc=linuxppc-dev@ozlabs.org \
--cc=mikey@neuling.org \
--cc=paulus@samba.org \
--cc=roland@redhat.com \
--cc=shaggy@linux.vnet.ibm.com \
--cc=stern@rowland.harvard.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).