[PATCH] x86-64/i386: Intel HT, Multi core detection fixes

Fields obtained through cpuid vector 0x1(ebx[16:23]) and
vector 0x4(eax[14:25], eax[26:31]) indicate the maximum values and might not
always be the same as what is available and what OS sees.  So make sure
"siblings" and "cpu cores" values in /proc/cpuinfo reflect the values as seen
by OS instead of what cpuid instruction says. This will also fix the buggy BIOS
cases (for example where cpuid on a single core cpu says there are "2" siblings,
even when HT is disabled in the BIOS.
http://bugzilla.kernel.org/show_bug.cgi?id=4359)

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 4 deletions

diff --git a/arch/i386/kernel/cpu/proc.c b/arch/i386/kernel/cpu/proc.c
index 41b871ecf4b3..e7921315ae9d 100644
--- a/arch/i386/kernel/cpu/proc.c
+++ b/arch/i386/kernel/cpu/proc.c
@@ -94,12 +94,11 @@ static int show_cpuinfo(struct seq_file *m, void *v)
         if (c->x86_cache_size >= 0)
                 seq_printf(m, "cache size\t: %d KB\n", c->x86_cache_size);
 #ifdef CONFIG_X86_HT
-        if (c->x86_num_cores * smp_num_siblings > 1) {
+        if (c->x86_max_cores * smp_num_siblings > 1) {
                 seq_printf(m, "physical id\t: %d\n", phys_proc_id[n]);
-                seq_printf(m, "siblings\t: %d\n",
-                                c->x86_num_cores * smp_num_siblings);
+                seq_printf(m, "siblings\t: %d\n", cpus_weight(cpu_core_map[n]));
                 seq_printf(m, "core id\t\t: %d\n", cpu_core_id[n]);
-                seq_printf(m, "cpu cores\t: %d\n", c->x86_num_cores);
+                seq_printf(m, "cpu cores\t: %d\n", c->booted_cores);
         }
 #endif