[22/89] x86, apic: use physical mode for IBM summit platforms
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From: Greg KH on 30 Mar 2010 20:40 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Suresh Siddha <suresh.b.siddha(a)intel.com> commit dfea91d5a7c795fd6f4e1a97489a98e4e767463e upstream. 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(a)intel.com> Tested-by: Ananth N Mavinakayanahalli <ananth(a)in.ibm.com> Cc: Chris McDermott <lcm(a)linux.vnet.ibm.com> Cc: Yinghai Lu <yinghai(a)kernel.org> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de> --- arch/x86/kernel/apic/apic_flat_64.c | 5 +++++ 1 file changed, 5 insertions(+) --- 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( 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |