From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Cc: Scott Wood <scottwood@freescale.com>,
"linuxppc-dev@ozlabs.org" <linuxppc-dev@ozlabs.org>,
Rex Feany <RFeany@mrv.com>
Subject: Re: [PATCH 4/6] 8xx: Tag DAR with 0x00f0 to catch buggy instructions.
Date: Thu, 08 Oct 2009 09:21:24 +1100 [thread overview]
Message-ID: <1254954084.2409.16.camel@pasglop> (raw)
In-Reply-To: <OF36596A29.5EDD5659-ONC1257648.0079FC5B-C1257648.007A1D0B@transmode.se>
On Thu, 2009-10-08 at 00:13 +0200, Joakim Tjernlund wrote:
> Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote on 07/10/2009 23:18:21:
> >
> > On Wed, 2009-10-07 at 22:46 +0200, Joakim Tjernlund wrote:
> > > dcbz, dcbf, dcbi, dcbst and icbi do not set DAR when they
> > > cause a DTLB Error. Dectect this by tagging DAR with 0x00f0
> > > at every exception exit that modifies DAR.
> > > Test for DAR=0x00f0 in DataTLBError and bail
> > > to handle_page_fault().
> >
> > Why not -1 ? :-)
>
> Because 0x00f0 is already in use in the TLB fast path, saves one insn.
But will cause weird things if the user really uses 0xf0 (though granted
that's unlikely :-)
Cheers,
Ben.
next prev parent reply other threads:[~2009-10-07 22:21 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-07 20:45 [PATCH 0/6] 8xx TLB fixes Joakim Tjernlund
2009-10-07 20:45 ` [PATCH 1/6] 8xx: DTLB Error must check for more errors Joakim Tjernlund
2009-10-07 20:46 ` [PATCH 2/6] 8xx: get rid of _PAGE_HWWRITE dependency in MMU Joakim Tjernlund
2009-10-07 20:46 ` [PATCH 3/6] 8xx: invalidate non present TLBs Joakim Tjernlund
2009-10-07 20:46 ` [PATCH 4/6] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund
2009-10-07 20:46 ` [PATCH 5/6] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund
2009-10-07 20:46 ` [PATCH 6/6] 8xx: start using dcbX instructions in various copy routines Joakim Tjernlund
2009-10-07 21:18 ` [PATCH 4/6] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Benjamin Herrenschmidt
2009-10-07 22:13 ` Joakim Tjernlund
2009-10-07 22:21 ` Benjamin Herrenschmidt [this message]
2009-10-07 23:12 ` Joakim Tjernlund
2009-10-07 21:18 ` [PATCH 3/6] 8xx: invalidate non present TLBs Benjamin Herrenschmidt
2009-10-07 22:12 ` Joakim Tjernlund
2009-10-07 22:20 ` Benjamin Herrenschmidt
2009-10-08 19:22 ` Joakim Tjernlund
2009-10-08 20:11 ` Dan Malek
2009-10-08 20:18 ` Benjamin Herrenschmidt
2009-10-08 20:28 ` Benjamin Herrenschmidt
2009-10-08 22:08 ` Dan Malek
2009-10-08 22:23 ` Benjamin Herrenschmidt
2009-10-08 23:01 ` Joakim Tjernlund
2009-10-09 0:56 ` Benjamin Herrenschmidt
2009-10-09 0:36 ` Dan Malek
2009-10-09 0:57 ` Benjamin Herrenschmidt
2009-10-08 20:37 ` Joakim Tjernlund
2009-10-08 20:44 ` Benjamin Herrenschmidt
2009-10-09 0:05 ` Dan Malek
2009-10-08 20:42 ` Benjamin Herrenschmidt
2009-10-07 21:14 ` [PATCH 2/6] 8xx: get rid of _PAGE_HWWRITE dependency in MMU Benjamin Herrenschmidt
2009-10-07 22:08 ` Joakim Tjernlund
2009-10-07 22:20 ` Benjamin Herrenschmidt
2009-10-07 23:11 ` Joakim Tjernlund
2009-10-08 0:04 ` Benjamin Herrenschmidt
2009-10-08 0:19 ` Joakim Tjernlund
2009-10-08 0:28 ` Benjamin Herrenschmidt
2009-10-08 6:45 ` Joakim Tjernlund
2009-10-08 20:21 ` Benjamin Herrenschmidt
[not found] ` <OFCA7943E6.AFEF924A-ONC1257648.007E27B0-C1257648.007F62E9@LocalDomain>
2009-10-07 23:34 ` Joakim Tjernlund
-- strict thread matches above, loose matches on Subject: below --
2009-10-08 13:24 [PATCH 0/6] 8xx MMU fixes Joakim Tjernlund
2009-10-08 13:24 ` [PATCH 1/6] 8xx: DTLB Error must check for more errors Joakim Tjernlund
2009-10-08 13:24 ` [PATCH 2/6] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund
2009-10-08 13:24 ` [PATCH 3/6] 8xx: invalidate non present TLBs Joakim Tjernlund
2009-10-08 13:24 ` [PATCH 4/6] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund
2009-10-05 12:16 [PATCH 0/6] PowerPc 8xx TLB/MMU fixes Joakim Tjernlund
2009-10-05 12:16 ` [PATCH 1/6] 8xx: DTLB Error must check for more errors Joakim Tjernlund
2009-10-05 12:16 ` [PATCH 2/6] 8xx, fault: Add some debug code to do_page_fault() Joakim Tjernlund
2009-10-05 12:16 ` [PATCH 3/6] 8xx: get rid of _PAGE_HWWRITE dependency in MMU Joakim Tjernlund
2009-10-05 12:16 ` [PATCH 4/6] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund
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