From: Martyn Welch <martyn.welch@gefanuc•com>
To: Kumar Gala <galak@kernel•crashing.org>
Cc: linuxppc-dev list <linuxppc-dev@ozlabs•org>
Subject: Re: [PATCH] powerpc/mm: Fix _PAGE_COHERENT support on classic ppc32 HW
Date: Mon, 16 Feb 2009 10:10:45 +0000 [thread overview]
Message-ID: <49993BA5.8080104@gefanuc.com> (raw)
In-Reply-To: <1234299466-17300-1-git-send-email-galak@kernel.crashing.org>
Kumar Gala wrote:
> The following commit:
>
> commit 64b3d0e8122b422e879b23d42f9e0e8efbbf9744
> Author: Benjamin Herrenschmidt <benh@kernel•crashing.org>
> Date: Thu Dec 18 19:13:51 2008 +0000
>
> powerpc/mm: Rework usage of _PAGE_COHERENT/NO_CACHE/GUARDED
>
> broke setting of the _PAGE_COHERENT bit in the PPC HW PTE. Since we now
> actually set _PAGE_COHERENT in the Linux PTE we shouldn't be clearing it
> out before we propogate it to the PPC HW PTE.
>
> Reported-by: Martyn Welch <martyn.welch@gefanuc•com>
> Signed-off-by: Kumar Gala <galak@kernel•crashing.org>
> ---
> arch/powerpc/mm/hash_low_32.S | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
> index 67850ec..14af8ce 100644
> --- a/arch/powerpc/mm/hash_low_32.S
> +++ b/arch/powerpc/mm/hash_low_32.S
> @@ -320,7 +320,7 @@ _GLOBAL(create_hpte)
> and r8,r8,r0 /* writable if _RW & _DIRTY */
> rlwimi r5,r5,32-1,30,30 /* _PAGE_USER -> PP msb */
> rlwimi r5,r5,32-2,31,31 /* _PAGE_USER -> PP lsb */
> - ori r8,r8,0xe14 /* clear out reserved bits and M */
> + ori r8,r8,0xe04 /* clear out reserved bits */
> andc r8,r5,r8 /* PP = user? (rw&dirty? 2: 3): 0 */
> BEGIN_FTR_SECTION
> rlwinm r8,r8,0,~_PAGE_COHERENT /* clear M (coherence not required) */
This does indeed resolve the problem I was having.
Sorry for not replying sooner - bad weather here in the UK unexpectedly extended a planned holiday.
Thank you for resolving this issue,
Martyn
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Martyn Welch MEng MPhil MIET (Principal Software Engineer) T:+44(0)1327322748
GE Fanuc Intelligent Platforms Ltd, |Registered in England and Wales
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prev parent reply other threads:[~2009-02-16 10:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-10 20:57 [PATCH] powerpc/mm: Fix _PAGE_COHERENT support on classic ppc32 HW Kumar Gala
2009-02-10 22:48 ` Becky Bruce
2009-02-16 10:10 ` Martyn Welch [this message]
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