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Subject[PATCH 2/2] x86/CPU/AMD: Derive CPU topology from CPUID Fn0xB
Date
Derive topology information from Extended Topology Enumeration
(CPUID Fn0x0000000B) when the information is available.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@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
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