From bbb65d2d365efe9951290e61678dcf81ec60add4 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Sat, 23 Aug 2008 17:47:10 +0200 Subject: x86: use cpuid vector 0xb when available for detecting cpu topology cpuid leaf 0xb provides extended topology enumeration. This interface provides the 32-bit x2APIC id of the logical processor and it also provides a new mechanism to detect SMT and core siblings (which provides increased addressability). Signed-off-by: Suresh Siddha Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/intel.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/cpu/intel.c') diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 77618c717d76..58a6f1a0b297 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -176,9 +176,16 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) if (p) strcpy(c->x86_model_id, p); - c->x86_max_cores = num_cpu_cores(c); - - detect_ht(c); + detect_extended_topology(c); + + if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) { + /* + * let's use the legacy cpuid vector 0x1 and 0x4 for topology + * detection. + */ + c->x86_max_cores = num_cpu_cores(c); + detect_ht(c); + } /* Work around errata */ Intel_errata_workarounds(c); -- cgit v1.2.1