From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Will Schmidt <will_schmidt@vnet.ibm.com>
Cc: linuxppc-dev@ozlabs.org, paulus@samba.org
Subject: Re: [PATCH] [Powerpc] fix switch_slb handling of 1T ESID values
Date: Sat, 27 Oct 2007 14:19:31 +1000 [thread overview]
Message-ID: <1193458771.18243.55.camel@pasglop> (raw)
In-Reply-To: <20071026204641.25514.45178.stgit@farscape.rchland.ibm.com>
On Fri, 2007-10-26 at 15:46 -0500, Will Schmidt wrote:
> [Powerpc] fix switch_slb handling of 1T ESID values
>
> Now that we have 1TB segment size support, we need to be using the
> GET_ESID_1T macro when comparing ESID values for pc,stack, and
> unmapped_base within switch_slb() when we're on a CPU that supports it.
>
> This also happens to fix a duplicate-slb-entry inspired machine-check
> exception I was seeing when trying to run java on a power6 partition.
>
> Tested on power6 and power5.
>
> Signed-Off-By: Will Schmidt <will_schmidt@vnet.ibm.com>
Good catch !
A minor comment is maybe you could factor out the code better doing
something like a ESID_COMPARE() macro ?
> ---
>
> There is a similar bit of code in stab.c switch_stab(). Should this change also be made there?
> ---
There is no machine that does stab and 1T segments.
Ben.
>
> arch/powerpc/mm/slb.c | 19 ++++++++++++++-----
> 1 files changed, 14 insertions(+), 5 deletions(-)
>
>
> diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
> index bbd2c51..0c527d7 100644
> --- a/arch/powerpc/mm/slb.c
> +++ b/arch/powerpc/mm/slb.c
> @@ -193,16 +193,25 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
> return;
> slb_allocate(pc);
>
> - if (GET_ESID(pc) == GET_ESID(stack))
> - return;
> + if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) {
> + if (GET_ESID_1T(pc) == GET_ESID_1T(stack))
> + return;
> + } else
> + if (GET_ESID(pc) == GET_ESID(stack))
> + return;
>
> if (is_kernel_addr(stack))
> return;
> slb_allocate(stack);
>
> - if ((GET_ESID(pc) == GET_ESID(unmapped_base))
> - || (GET_ESID(stack) == GET_ESID(unmapped_base)))
> - return;
> + if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) {
> + if ((GET_ESID_1T(pc) == GET_ESID_1T(unmapped_base))
> + || (GET_ESID_1T(stack) == GET_ESID_1T(unmapped_base)))
> + return;
> + } else
> + if ((GET_ESID(pc) == GET_ESID(unmapped_base))
> + || (GET_ESID(stack) == GET_ESID(unmapped_base)))
> + return;
>
> if (is_kernel_addr(unmapped_base))
> return;
>
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
next prev parent reply other threads:[~2007-10-27 4:19 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-26 20:46 [PATCH] [Powerpc] fix switch_slb handling of 1T ESID values Will Schmidt
2007-10-27 4:19 ` Benjamin Herrenschmidt [this message]
2007-10-27 17:36 ` Will Schmidt
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