[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>

5 files changed, 25 insertions, 34 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
 }
diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c
index 35a67dab4a94..4e9c2e99b0a5 100644
--- a/arch/i386/kernel/cpu/common.c
+++ b/arch/i386/kernel/cpu/common.c
@@ -335,7 +335,7 @@ void __devinit identify_cpu(struct cpuinfo_x86 *c)
         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 identify_cpu(struct cpuinfo_x86 *c)
 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]);
         }
diff --git a/arch/i386/kernel/cpu/intel.c b/arch/i386/kernel/cpu/intel.c
index 43601de0f633..8d603ba28126 100644
--- a/arch/i386/kernel/cpu/intel.c
+++ b/arch/i386/kernel/cpu/intel.c
@@ -157,7 +157,7 @@ static void __devinit init_intel(struct cpuinfo_x86 *c)
         if ( p )
                 strcpy(c->x86_model_id, p);
         
-        c->x86_num_cores = num_cpu_cores(c);
+        c->x86_max_cores = num_cpu_cores(c);
 
         detect_ht(c);
 
diff --git a/arch/i386/kernel/cpu/intel_cacheinfo.c b/arch/i386/kernel/cpu/intel_cacheinfo.c
index 4dc42a189ae5..e66d14099564 100644
--- a/arch/i386/kernel/cpu/intel_cacheinfo.c
+++ b/arch/i386/kernel/cpu/intel_cacheinfo.c
@@ -307,7 +307,7 @@ static void __cpuinit cache_shared_cpu_map_setup(unsigned int cpu, int index)
 #ifdef CONFIG_X86_HT
         else if (num_threads_sharing == smp_num_siblings)
                 this_leaf->shared_cpu_map = cpu_sibling_map[cpu];
-        else if (num_threads_sharing == (c->x86_num_cores * smp_num_siblings))
+        else if (num_threads_sharing == (c->x86_max_cores * smp_num_siblings))
                 this_leaf->shared_cpu_map = cpu_core_map[cpu];
         else
                 printk(KERN_DEBUG "Number of CPUs sharing cache didn't match "
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