4 files changed, 19 insertions, 4 deletions

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 1be64da0384e..e6cfe7ba2d65 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -104,6 +104,7 @@ struct cpuinfo_x86 {
         __u8                    x86_phys_bits;
         /* CPUID returned core id bits: */
         __u8                    x86_coreid_bits;
+        __u8                    cu_id;
         /* Max extended CPUID function supported: */
         __u32                   extended_cpuid_level;
         /* Maximum supported CPUID level, -1=no CPUID: */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 1d3167269a67..20dc44d1e6be 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -309,8 +309,15 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
 
         /* get information required for multi-node processors */
         if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
+                u32 eax, ebx, ecx, edx;
 
-                node_id = cpuid_ecx(0x8000001e) & 7;
+                cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
+
+                node_id  = ecx & 0xff;
+                smp_num_siblings = ((ebx >> 8) & 0xff) + 1;
+
+                if (c->x86 == 0x15)
+                        c->cu_id = ebx & 0xff;
 
                 /*
                  * We may have multiple LLCs if L3 caches exist, so check if we
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9bab7a8a4293..ede03e849a8b 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1015,6 +1015,7 @@ static void identify_cpu(struct cpuinfo_x86 *c)
         c->x86_model_id[0] = '\0';  /* Unset */
         c->x86_max_cores = 1;
         c->x86_coreid_bits = 0;
+        c->cu_id = 0xff;
 #ifdef CONFIG_X86_64
         c->x86_clflush_size = 64;
         c->x86_phys_bits = 36;
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 46732dc3b73c..99b920d0e516 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -433,9 +433,15 @@ static bool match_smt(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
                 int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
 
                 if (c->phys_proc_id == o->phys_proc_id &&
-                    per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2) &&
-                    c->cpu_core_id == o->cpu_core_id)
-                        return topology_sane(c, o, "smt");
+                    per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2)) {
+                        if (c->cpu_core_id == o->cpu_core_id)
+                                return topology_sane(c, o, "smt");
+
+                        if ((c->cu_id != 0xff) &&
+                            (o->cu_id != 0xff) &&
+                            (c->cu_id == o->cu_id))
+                                return topology_sane(c, o, "smt");
+                }
 
         } else if (c->phys_proc_id == o->phys_proc_id &&
                    c->cpu_core_id == o->cpu_core_id) {