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authorSuresh Siddha <suresh.b.siddha@intel.com>2010-01-18 12:10:48 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2010-01-18 14:15:27 -0800
commitdfea91d5a7c795fd6f4e1a97489a98e4e767463e (patch)
treef4e60892201bd21cb0f1c462861dd28f3c0437d2 /arch/x86/kernel
parent54ef91dcf094313fb4fbe87713c11fb55bcf15a9 (diff)
x86, apic: use physical mode for IBM summit platforms
Chris McDermott from IBM confirmed that hurricane chipset in IBM summit platforms doesn't support logical flat mode. Irrespective of the other things like apic_id's, total number of logical cpu's, Linux kernel should default to physical mode for this system. The 32-bit kernel does so using the OEM checks for the IBM summit platform. Add a similar OEM platform check for the 64bit kernel too. Otherwise the linux kernel boot can hang on this platform under certain bios/platform settings. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Chris McDermott <lcm@linux.vnet.ibm.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/apic/apic_flat_64.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
index eacbd2b31d2..e3c3d820c32 100644
--- a/arch/x86/kernel/apic/apic_flat_64.c
+++ b/arch/x86/kernel/apic/apic_flat_64.c
@@ -240,6 +240,11 @@ static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
printk(KERN_DEBUG "system APIC only can use physical flat");
return 1;
}
+
+ if (!strncmp(oem_id, "IBM", 3) && !strncmp(oem_table_id, "EXA", 3)) {
+ printk(KERN_DEBUG "IBM Summit detected, will use apic physical");
+ return 1;
+ }
#endif
return 0;