[PATCH 2/2] x86/CPU/AMD: Derive CPU topology from CPUID Fn0xB

[Suravee Suthikulpanit]

Derive topology information from Extended Topology Enumeration
(CPUID Fn0x0000000B) when the information is available.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
---
 arch/x86/kernel/cpu/amd.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 2c1a9f2..2b40144 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -338,10 +338,18 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
                        c->cu_id = ebx & 0xff;
 
                if (c->x86 >= 0x17) {
-                       c->cpu_core_id = ebx & 0xff;
+                       int err = detect_extended_topology(c);
 
-                       if (smp_num_siblings > 1)
-                               c->x86_max_cores /= smp_num_siblings;
+                       if (err) {
+                               c->cpu_core_id = ebx & 0xff;
+
+                               if (smp_num_siblings > 1)
+                                       c->x86_max_cores /= smp_num_siblings;
+                       } else {
+                               int bits = get_count_order(c->x86_max_cores);
+
+                               c->x86_coreid_bits = get_count_order(bits);
+                       }
                }
 
                cacheinfo_amd_init_llc_id(c, cpu, node_id);
@@ -378,7 +386,6 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c)
        c->phys_proc_id = c->initial_apicid >> bits;
        /* use socket ID also for last level cache */
        per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
-       amd_get_topology(c);
 }
 
 u16 amd_get_nb_id(int cpu)
@@ -823,6 +830,7 @@ static void init_amd(struct cpuinfo_x86 *c)
        /* Multi core CPU? */
        if (c->extended_cpuid_level >= 0x80000008) {
                amd_detect_cmp(c);
+               amd_get_topology(c);
                srat_detect_node(c);
        }
 
-- 
2.7.4