[PATCH] x86/cpu: detect extended topology for Zhaoxin CPUs

From: Tony W Wang-oc
Date: Tue Jun 06 2023 - 05:32:22 EST


Zhaoxin CPUs support extended topology enumeration
CPUID leaf 0xb/0x1f.
Right now the kernel uses the legacy CPUID leaf 0x1/0x4
for topology detection for Zhaoxin CPUs.
So add extended topology detection support for these
Zhaoxin CPUs.

Signed-off-by: Tony W Wang-oc <TonyWWang-oc@xxxxxxxxxxx>
---
arch/x86/kernel/cpu/centaur.c | 11 +++++++++--
arch/x86/kernel/cpu/zhaoxin.c | 10 ++++++++--
2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/centaur.c b/arch/x86/kernel/cpu/centaur.c
index 345f7d905db6..627a90f5ef52 100644
--- a/arch/x86/kernel/cpu/centaur.c
+++ b/arch/x86/kernel/cpu/centaur.c
@@ -109,6 +109,9 @@ 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 (detect_extended_topology_early(c) < 0)
+ detect_ht_early(c);
}

static void init_centaur(struct cpuinfo_x86 *c)
@@ -127,11 +130,15 @@ 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);
+ 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 05fa4ef63490..37ad1ceb27a1 100644
--- a/arch/x86/kernel/cpu/zhaoxin.c
+++ b/arch/x86/kernel/cpu/zhaoxin.c
@@ -79,16 +79,22 @@ 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 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);
+ detect_ht(c);
#endif
+ }

if (c->cpuid_level > 9) {
unsigned int eax = cpuid_eax(10);
--
2.17.1