[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, 1 deletions

diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index 0a4ec764377c..9cd4a05234a1 100644
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -65,7 +65,9 @@ struct cpuinfo_x86 {
         int     f00f_bug;
         int     coma_bug;
         unsigned long loops_per_jiffy;
-        unsigned char x86_num_cores;
+        unsigned char x86_max_cores;    /* cpuid returned max cores value */
+        unsigned char booted_cores;     /* number of cores as seen by OS */
+        unsigned char apicid;
 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
 
 #define X86_VENDOR_INTEL 0