x86, mrst: add nop functions to x86_init mpparse functions

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@linux.intel.com>
LKML-Reference: <1273873281-17489-8-git-send-email-jacob.jun.pan@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/x86/kernel/mrst.c b/arch/x86/kernel/mrst.c
index 0aad8670858e..e796448f0eb5 100644
--- a/arch/x86/kernel/mrst.c
+++ b/arch/x86/kernel/mrst.c
@@ -237,4 +237,9 @@ 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;
+
 }