From: Scott Wood <scottwood@freescale•com>
To: Joakim Tjernlund <Joakim.Tjernlund@transmode•se>
Cc: Rex Feany <RFeany@mrv•com>,
"linuxppc-dev@ozlabs•org" <linuxppc-dev@ozlabs•org>
Subject: Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions.
Date: Wed, 14 Oct 2009 12:20:03 -0500 [thread overview]
Message-ID: <20091014172003.GD21215@loki.buserror.net> (raw)
In-Reply-To: <1255278912-8042-5-git-send-email-Joakim.Tjernlund@transmode.se>
On Sun, Oct 11, 2009 at 06:35:08PM +0200, Joakim Tjernlund wrote:
> This is an assembler version to fixup DAR not being set
> by dcbX, icbi instructions. There are two versions, one
> uses selfmodifing code, the other uses a
> jump table but is much bigger(default).
> ---
> arch/powerpc/kernel/head_8xx.S | 146 +++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 145 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
> index 093176c..9839e79 100644
> --- a/arch/powerpc/kernel/head_8xx.S
> +++ b/arch/powerpc/kernel/head_8xx.S
> @@ -494,7 +494,8 @@ DataTLBError:
>
> mfspr r10, SPRN_DAR
> cmpwi cr0, r10, 0x00f0
> - beq- 2f /* must be a buggy dcbX, icbi insn. */
> + beq- FixDAR /* must be a buggy dcbX, icbi insn. */
> +DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR */
Both FixDAR and DARFix? Could we make the labels a little clearer?
> +/* This is the procedure to calculate the data EA for buggy dcbx,dcbi instructions
> + * by decoding the registers used by the dcbx instruction and adding them.
> + * DAR is set to the calculated address and r10 also holds the EA on exit.
> + */
How often does this happen? Could we just do it in C code after saving all
the registers, and avoid the self modifying stuff (or the big switch
statement equivalent)?
-Scott
next prev parent reply other threads:[~2009-10-14 17:19 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-11 16:35 [PATCH 0/8] Fix 8xx MMU/TLB Joakim Tjernlund
2009-10-11 16:35 ` [PATCH 1/8] 8xx: invalidate non present TLBs Joakim Tjernlund
2009-10-11 16:35 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund
2009-10-11 16:35 ` [PATCH 3/8] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund
2009-10-11 16:35 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund
2009-10-11 16:35 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Joakim Tjernlund
2009-10-11 16:35 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Joakim Tjernlund
2009-10-11 16:35 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Joakim Tjernlund
2009-10-11 16:35 ` [PATCH 8/8] 8xx: start using dcbX instructions in various copy routines Joakim Tjernlund
2009-10-11 21:26 ` [PATCH 7/8] 8xx: Restore _PAGE_WRITETHRU Benjamin Herrenschmidt
2009-10-11 22:21 ` Joakim Tjernlund
2009-10-11 22:45 ` Benjamin Herrenschmidt
2009-10-11 21:25 ` [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error Benjamin Herrenschmidt
2009-10-11 22:19 ` Joakim Tjernlund
2009-10-11 22:44 ` Benjamin Herrenschmidt
2009-10-12 5:36 ` Joakim Tjernlund
2009-10-12 5:46 ` Benjamin Herrenschmidt
2009-10-12 6:59 ` Joakim Tjernlund
2009-10-14 17:02 ` [PATCH 5/8] 8xx: dcbst sets store bit in DTLB error, workaround Scott Wood
2009-10-14 17:20 ` Scott Wood [this message]
2009-10-14 19:05 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund
2009-10-14 19:23 ` Scott Wood
2009-10-14 20:03 ` Joakim Tjernlund
2009-10-14 20:22 ` Scott Wood
2009-10-14 21:10 ` Joakim Tjernlund
2009-10-14 21:14 ` Scott Wood
2009-10-14 21:17 ` Benjamin Herrenschmidt
2009-10-14 21:41 ` Joakim Tjernlund
2009-10-14 21:52 ` Benjamin Herrenschmidt
2009-10-14 22:09 ` Joakim Tjernlund
2009-10-11 21:25 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Benjamin Herrenschmidt
2009-10-14 16:57 ` Scott Wood
2009-10-14 16:56 ` [PATCH 1/8] 8xx: invalidate non present TLBs Scott Wood
2009-10-14 17:23 ` [PATCH 0/8] Fix 8xx MMU/TLB Scott Wood
2009-10-14 18:46 ` Joakim Tjernlund
-- strict thread matches above, loose matches on Subject: below --
2009-10-15 9:04 Joakim Tjernlund
2009-10-15 9:04 ` [PATCH 1/8] 8xx: invalidate non present TLBs Joakim Tjernlund
2009-10-15 9:04 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund
2009-10-15 9:04 ` [PATCH 3/8] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund
2009-10-15 9:04 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund
2009-11-04 13:38 [PATCH 0/8] 8xx: Misc fixes for buggy insn Joakim Tjernlund
2009-11-04 13:38 ` [PATCH 1/8] 8xx: invalidate non present TLBs Joakim Tjernlund
2009-11-04 13:38 ` [PATCH 2/8] 8xx: Update TLB asm so it behaves as linux mm expects Joakim Tjernlund
2009-11-04 13:38 ` [PATCH 3/8] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund
2009-11-04 13:38 ` [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund
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