[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, 6 insertions, 6 deletions

diff --git a/arch/i386/kernel/cpu/amd.c b/arch/i386/kernel/cpu/amd.c
index 53a1681cd964..e344ef88cfcd 100644
--- a/arch/i386/kernel/cpu/amd.c
+++ b/arch/i386/kernel/cpu/amd.c
@@ -206,9 +206,9 @@ static void __init init_amd(struct cpuinfo_x86 *c)
         display_cacheinfo(c);
 
         if (cpuid_eax(0x80000000) >= 0x80000008) {
-                c->x86_num_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
-                if (c->x86_num_cores & (c->x86_num_cores - 1))
-                        c->x86_num_cores = 1;
+                c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
+                if (c->x86_max_cores & (c->x86_max_cores - 1))
+                        c->x86_max_cores = 1;
         }
 
 #ifdef CONFIG_X86_HT
@@ -217,15 +217,15 @@ static void __init init_amd(struct cpuinfo_x86 *c)
          * distingush the cores.  Assumes number of cores is a power
          * of two.
          */
-        if (c->x86_num_cores > 1) {
+        if (c->x86_max_cores > 1) {
                 int cpu = smp_processor_id();
                 unsigned bits = 0;
-                while ((1 << bits) < c->x86_num_cores)
+                while ((1 << bits) < c->x86_max_cores)
                         bits++;
                 cpu_core_id[cpu] = phys_proc_id[cpu] & ((1<<bits)-1);
                 phys_proc_id[cpu] >>= bits;
                 printk(KERN_INFO "CPU %d(%d) -> Core %d\n",
-                       cpu, c->x86_num_cores, cpu_core_id[cpu]);
+                       cpu, c->x86_max_cores, cpu_core_id[cpu]);
         }
 #endif
 }