[patch V4 26/41] x86/cpu: Use common topology code for Centaur and Zhaoxin

From: Thomas Gleixner
Date: Mon Aug 14 2023 - 04:56:10 EST


Centaur and Zhaoxin CPUs use only the legacy SMP detection. Remove the
invocations from their 32bit path and exempt them from the call 64bit.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Juergen Gross <jgross@xxxxxxxx>
Tested-by: Sohil Mehta <sohil.mehta@xxxxxxxxx>
Tested-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>

---
arch/x86/kernel/cpu/centaur.c | 4 ----
arch/x86/kernel/cpu/topology_common.c | 11 ++++++++---
arch/x86/kernel/cpu/zhaoxin.c | 4 ----
3 files changed, 8 insertions(+), 11 deletions(-)

--- a/arch/x86/kernel/cpu/centaur.c
+++ b/arch/x86/kernel/cpu/centaur.c
@@ -128,10 +128,6 @@ static void init_centaur(struct cpuinfo_
#endif
early_init_centaur(c);
init_intel_cacheinfo(c);
- detect_num_cpu_cores(c);
-#ifdef CONFIG_X86_32
- detect_ht(c);
-#endif

if (c->cpuid_level > 9) {
unsigned int eax = cpuid_eax(10);
--- a/arch/x86/kernel/cpu/topology_common.c
+++ b/arch/x86/kernel/cpu/topology_common.c
@@ -42,7 +42,7 @@ static unsigned int parse_num_cores(stru
return eax.ncores + 1;
}

-static void __maybe_unused parse_legacy(struct topo_scan *tscan)
+static void parse_legacy(struct topo_scan *tscan)
{
unsigned int cores, core_shift, smt_shift = 0;
struct cpuinfo_x86 *c = tscan->c;
@@ -71,10 +71,8 @@ bool topo_is_converted(struct cpuinfo_x8
/* Temporary until everything is converted over. */
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
- case X86_VENDOR_CENTAUR:
case X86_VENDOR_INTEL:
case X86_VENDOR_HYGON:
- case X86_VENDOR_ZHAOXIN:
return false;
default:
/* Let all UP systems use the below */
@@ -132,6 +130,13 @@ static void parse_topology(struct topo_s
return;

tscan->ebx1_nproc_shift = get_count_order(ebx.nproc);
+
+ switch (c->x86_vendor) {
+ case X86_VENDOR_CENTAUR:
+ case X86_VENDOR_ZHAOXIN:
+ parse_legacy(tscan);
+ break;
+ }
}

static void topo_set_ids(struct topo_scan *tscan)
--- a/arch/x86/kernel/cpu/zhaoxin.c
+++ b/arch/x86/kernel/cpu/zhaoxin.c
@@ -71,10 +71,6 @@ static void init_zhaoxin(struct cpuinfo_
{
early_init_zhaoxin(c);
init_intel_cacheinfo(c);
- detect_num_cpu_cores(c);
-#ifdef CONFIG_X86_32
- detect_ht(c);
-#endif

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