[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>
diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c
index 35a67da..4e9c2e9 100644
--- a/arch/i386/kernel/cpu/common.c
+++ b/arch/i386/kernel/cpu/common.c
@@ -335,7 +335,7 @@
c->x86_model = c->x86_mask = 0; /* So far unknown... */
c->x86_vendor_id[0] = '\0'; /* Unset */
c->x86_model_id[0] = '\0'; /* Unset */
- c->x86_num_cores = 1;
+ c->x86_max_cores = 1;
memset(&c->x86_capability, 0, sizeof c->x86_capability);
if (!have_cpuid_p()) {
@@ -446,52 +446,44 @@
void __devinit detect_ht(struct cpuinfo_x86 *c)
{
u32 eax, ebx, ecx, edx;
- int index_msb, tmp;
+ int index_msb, core_bits;
int cpu = smp_processor_id();
+ cpuid(1, &eax, &ebx, &ecx, &edx);
+
+ c->apicid = phys_pkg_id((ebx >> 24) & 0xFF, 0);
+
if (!cpu_has(c, X86_FEATURE_HT) || cpu_has(c, X86_FEATURE_CMP_LEGACY))
return;
- cpuid(1, &eax, &ebx, &ecx, &edx);
smp_num_siblings = (ebx & 0xff0000) >> 16;
if (smp_num_siblings == 1) {
printk(KERN_INFO "CPU: Hyper-Threading is disabled\n");
} else if (smp_num_siblings > 1 ) {
- index_msb = 31;
if (smp_num_siblings > NR_CPUS) {
printk(KERN_WARNING "CPU: Unsupported number of the siblings %d", smp_num_siblings);
smp_num_siblings = 1;
return;
}
- tmp = smp_num_siblings;
- while ((tmp & 0x80000000 ) == 0) {
- tmp <<=1 ;
- index_msb--;
- }
- if (smp_num_siblings & (smp_num_siblings - 1))
- index_msb++;
+
+ index_msb = get_count_order(smp_num_siblings);
phys_proc_id[cpu] = phys_pkg_id((ebx >> 24) & 0xFF, index_msb);
printk(KERN_INFO "CPU: Physical Processor ID: %d\n",
phys_proc_id[cpu]);
- smp_num_siblings = smp_num_siblings / c->x86_num_cores;
+ smp_num_siblings = smp_num_siblings / c->x86_max_cores;
- tmp = smp_num_siblings;
- index_msb = 31;
- while ((tmp & 0x80000000) == 0) {
- tmp <<=1 ;
- index_msb--;
- }
+ index_msb = get_count_order(smp_num_siblings) ;
- if (smp_num_siblings & (smp_num_siblings - 1))
- index_msb++;
+ core_bits = get_count_order(c->x86_max_cores);
- cpu_core_id[cpu] = phys_pkg_id((ebx >> 24) & 0xFF, index_msb);
+ cpu_core_id[cpu] = phys_pkg_id((ebx >> 24) & 0xFF, index_msb) &
+ ((1 << core_bits) - 1);
- if (c->x86_num_cores > 1)
+ if (c->x86_max_cores > 1)
printk(KERN_INFO "CPU: Processor Core ID: %d\n",
cpu_core_id[cpu]);
}