Re: [PATCH 7/8] x86/mrst: add nop functions to x86_init mpparsefunctions

From: Thomas Gleixner
Date: Sun May 16 2010 - 18:45:19 EST


On Fri, 14 May 2010, Jacob Pan wrote:

> Moorestown does not have BIOS provided MP tables, we can save some time
> by avoiding scaning of these tables. e.g.
> [ 0.000000] Scan SMP from c0000000 for 1024 bytes.
> [ 0.000000] Scan SMP from c009fc00 for 1024 bytes.
> [ 0.000000] Scan SMP from c00f0000 for 65536 bytes.
> [ 0.000000] Scan SMP from c00bfff0 for 1024 bytes.
>
> Searching EBDA with the base at 0x40E will also result in random pointer
> deferencing within 1MB. This can be a problem in Lincroft if the pointer
> hits VGA area and VGA mode is not enabled.
>
> Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>

Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

> ---
> arch/x86/kernel/mrst.c | 5 +++++
> 1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kernel/mrst.c b/arch/x86/kernel/mrst.c
> index 83c23d6..9b62d32 100644
> --- a/arch/x86/kernel/mrst.c
> +++ b/arch/x86/kernel/mrst.c
> @@ -311,4 +311,9 @@ void __init x86_mrst_early_setup(void)
> x86_init.pci.fixup_irqs = x86_init_noop;
>
> legacy_pic = &null_legacy_pic;
> +
> + /* Avoid searching for BIOS MP tables */
> + x86_init.mpparse.find_smp_config = x86_init_noop;
> + x86_init.mpparse.get_smp_config = x86_init_uint_noop;
> +
> }
> --
> 1.6.3.3
>
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