[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/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index 476ee03..40c77f6 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -795,7 +795,7 @@
#endif
bits = 0;
- while ((1 << bits) < c->x86_num_cores)
+ while ((1 << bits) < c->x86_max_cores)
bits++;
/* Low order bits define the core id (index of core in socket) */
@@ -828,7 +828,7 @@
numa_set_node(cpu, node);
printk(KERN_INFO "CPU %d(%d) -> Node %d -> Core %d\n",
- cpu, c->x86_num_cores, node, cpu_core_id[cpu]);
+ cpu, c->x86_max_cores, node, cpu_core_id[cpu]);
#endif
#endif
}
@@ -877,9 +877,9 @@
display_cacheinfo(c);
if (c->extended_cpuid_level >= 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;
amd_detect_cmp(c);
}
@@ -891,54 +891,44 @@
{
#ifdef CONFIG_SMP
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(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;
- /*
- * At this point we only support two siblings per
- * processor package.
- */
+ } else if (smp_num_siblings > 1 ) {
+
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(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--;
- }
- if (smp_num_siblings & (smp_num_siblings - 1))
- index_msb++;
+ index_msb = get_count_order(smp_num_siblings) ;
- cpu_core_id[cpu] = phys_pkg_id(index_msb);
+ core_bits = get_count_order(c->x86_max_cores);
- if (c->x86_num_cores > 1)
+ cpu_core_id[cpu] = phys_pkg_id(index_msb) &
+ ((1 << core_bits) - 1);
+
+ if (c->x86_max_cores > 1)
printk(KERN_INFO "CPU: Processor Core ID: %d\n",
cpu_core_id[cpu]);
}
@@ -1006,7 +996,7 @@
c->x86_cache_alignment = c->x86_clflush_size * 2;
if (c->x86 >= 15)
set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability);
- c->x86_num_cores = intel_num_cpu_cores(c);
+ c->x86_max_cores = intel_num_cpu_cores(c);
srat_detect_node();
}
@@ -1044,7 +1034,7 @@
c->x86_model_id[0] = '\0'; /* Unset */
c->x86_clflush_size = 64;
c->x86_cache_alignment = c->x86_clflush_size;
- c->x86_num_cores = 1;
+ c->x86_max_cores = 1;
c->extended_cpuid_level = 0;
memset(&c->x86_capability, 0, sizeof c->x86_capability);
@@ -1278,13 +1268,12 @@
seq_printf(m, "cache size\t: %d KB\n", c->x86_cache_size);
#ifdef CONFIG_SMP
- if (smp_num_siblings * c->x86_num_cores > 1) {
+ if (smp_num_siblings * c->x86_max_cores > 1) {
int cpu = c - cpu_data;
seq_printf(m, "physical id\t: %d\n", phys_proc_id[cpu]);
- 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[cpu]));
seq_printf(m, "core id\t\t: %d\n", cpu_core_id[cpu]);
- seq_printf(m, "cpu cores\t: %d\n", c->x86_num_cores);
+ seq_printf(m, "cpu cores\t: %d\n", c->booted_cores);
}
#endif
