Detect the extended topology information of Zhaoxin CPUs if available. The patch is scheduled to be submitted to the kernel mainline in 2021. --- v1->v2:     - Fix a code logic issue. Signed-off-by: LeoLiu-oc &lt;LeoLiu-oc(a)zhaoxin.com&gt; ---  arch/x86/kernel/cpu/centaur.c | 20 +++++++++++++++++++-  arch/x86/kernel/cpu/zhaoxin.c |  7 ++++++-  2 files changed, 25 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/centaur.c b/arch/x86/kernel/cpu/centaur.c index 8735be464bc1..608b8dfa119f 100644 --- a/arch/x86/kernel/cpu/centaur.c +++ b/arch/x86/kernel/cpu/centaur.c @@ -115,6 +115,21 @@ static void early_init_centaur(struct cpuinfo_x86 *c)         set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);         set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);     } + +   if (c->cpuid_level >= 0x00000001) { +       u32 eax, ebx, ecx, edx; + +       cpuid(0x00000001, &eax, &ebx, &ecx, &edx); +       /* +        * If HTT (EDX[28]) is set EBX[16:23] contain the number of +        * apicids which are reserved per package. Store the resulting +        * shift value for the package management code. +        */ +       if (edx & (1U << 28)) +           c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff); +   } +   if (detect_extended_topology_early(c) < 0) +       detect_ht_early(c);  }  static void centaur_detect_vmx_virtcap(struct cpuinfo_x86 *c) @@ -158,11 +173,14 @@ static void init_centaur(struct cpuinfo_x86 *c)     clear_cpu_cap(c, 0*32+31);  #endif     early_init_centaur(c); +   detect_extended_topology(c);     init_intel_cacheinfo(c); -   detect_num_cpu_cores(c); +   if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) { +       detect_num_cpu_cores(c);  #ifdef CONFIG_X86_32     detect_ht(c);  #endif +   }     if (c->cpuid_level > 9) {         unsigned int eax = cpuid_eax(10); diff --git a/arch/x86/kernel/cpu/zhaoxin.c b/arch/x86/kernel/cpu/zhaoxin.c index 452fd0a6bc61..e4ed34361a1f 100644 --- a/arch/x86/kernel/cpu/zhaoxin.c +++ b/arch/x86/kernel/cpu/zhaoxin.c @@ -85,6 +85,8 @@ static void early_init_zhaoxin(struct cpuinfo_x86 *c)             c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff);     } +   if (detect_extended_topology_early(c) < 0) +       detect_ht_early(c);  }  static void zhaoxin_detect_vmx_virtcap(struct cpuinfo_x86 *c) @@ -115,11 +117,14 @@ static void zhaoxin_detect_vmx_virtcap(struct cpuinfo_x86 *c)  static void init_zhaoxin(struct cpuinfo_x86 *c)  {     early_init_zhaoxin(c); +   detect_extended_topology(c);     init_intel_cacheinfo(c); -   detect_num_cpu_cores(c); +   if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) { +       detect_num_cpu_cores(c);  #ifdef CONFIG_X86_32     detect_ht(c);  #endif +   }     if (c->cpuid_level > 9) {         unsigned int eax = cpuid_eax(10); -- 2.20.1