x86/cpu/topology: Rename smp_num_siblings

It's really a non-intuitive name. Rename it to __max_threads_per_core which
is obvious.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210253.011307973@linutronix.de

Author: KAGA-KOKO

arch/x86/include/asm/perf_event_p4.h

@@ -181,15 +181,15 @@ static inline u64 p4_clear_ht_bit(u64 config)
 static inline int p4_ht_active(void)
 {
 #ifdef CONFIG_SMP
-	return smp_num_siblings > 1;
+	return __max_threads_per_core > 1;
 #endif
 	return 0;
 }
 
 static inline int p4_ht_thread(int cpu)
 {
 #ifdef CONFIG_SMP
-	if (smp_num_siblings == 2)
+	if (__max_threads_per_core == 2)
 		return cpu != cpumask_first(this_cpu_cpumask_var_ptr(cpu_sibling_map));
 #endif
 	return 0;

arch/x86/include/asm/smp.h

@@ -8,8 +8,6 @@
 #include <asm/current.h>
 #include <asm/thread_info.h>
 
-extern unsigned int smp_num_siblings;
-
 DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
 DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
 DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_die_map);

arch/x86/include/asm/topology.h

@@ -145,6 +145,7 @@ extern const struct cpumask *cpu_clustergroup_mask(int cpu);
 
 extern unsigned int __max_dies_per_package;
 extern unsigned int __max_logical_packages;
+extern unsigned int __max_threads_per_core;
 
 static inline unsigned int topology_max_packages(void)
 {

arch/x86/kernel/cpu/common.c

@@ -73,8 +73,8 @@
 u32 elf_hwcap2 __read_mostly;
 
 /* Number of siblings per CPU package */
-unsigned int smp_num_siblings __ro_after_init = 1;
-EXPORT_SYMBOL(smp_num_siblings);
+unsigned int __max_threads_per_core __ro_after_init = 1;
+EXPORT_SYMBOL(__max_threads_per_core);
 
 unsigned int __max_dies_per_package __ro_after_init = 1;
 EXPORT_SYMBOL(__max_dies_per_package);
@@ -2251,7 +2251,7 @@ void __init arch_cpu_finalize_init(void)
 	 * identify_boot_cpu() initialized SMT support information, let the
 	 * core code know.
 	 */
-	cpu_smt_set_num_threads(smp_num_siblings, smp_num_siblings);
+	cpu_smt_set_num_threads(__max_threads_per_core, __max_threads_per_core);
 
 	if (!IS_ENABLED(CONFIG_SMP)) {
 		pr_info("CPU: ");

arch/x86/kernel/cpu/debugfs.c

@@ -30,7 +30,7 @@ static int cpu_debug_show(struct seq_file *m, void *p)
 	seq_printf(m, "amd_nodes_per_pkg:   %u\n", topology_amd_nodes_per_pkg());
 	seq_printf(m, "max_cores:           %u\n", c->x86_max_cores);
 	seq_printf(m, "max_dies_per_pkg:    %u\n", __max_dies_per_package);
-	seq_printf(m, "smp_num_siblings:    %u\n", smp_num_siblings);
+	seq_printf(m, "max_threads_per_core:%u\n", __max_threads_per_core);
 	return 0;
 }
 

arch/x86/kernel/cpu/mce/inject.c

@@ -433,7 +433,7 @@ static u32 get_nbc_for_node(int node_id)
 	struct cpuinfo_x86 *c = &boot_cpu_data;
 	u32 cores_per_node;
 
-	cores_per_node = (c->x86_max_cores * smp_num_siblings) / topology_amd_nodes_per_pkg();
+	cores_per_node = (c->x86_max_cores * __max_threads_per_core) / topology_amd_nodes_per_pkg();
 	return cores_per_node * node_id;
 }
 

arch/x86/kernel/cpu/topology.c

@@ -76,7 +76,7 @@ bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
 #ifdef CONFIG_SMP
 static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid)
 {
-	if (!(apicid & (smp_num_siblings - 1)))
+	if (!(apicid & (__max_threads_per_core - 1)))
 		cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
 }
 #else
@@ -429,8 +429,8 @@ void __init topology_init_possible_cpus(void)
 	 * Can't use order delta here as order(cnta) can be equal
 	 * order(cntb) even if cnta != cntb.
 	 */
-	smp_num_siblings = DIV_ROUND_UP(cntb, cnta);
-	pr_info("Max. threads per core: %3u\n", smp_num_siblings);
+	__max_threads_per_core = DIV_ROUND_UP(cntb, cnta);
+	pr_info("Max. threads per core: %3u\n", __max_threads_per_core);
 
 	pr_info("Allowing %u present CPUs plus %u hotplug CPUs\n", assigned, disabled);
 	if (topo_info.nr_rejected_cpus)

arch/x86/kernel/process.c

@@ -936,7 +936,7 @@ static __cpuidle void mwait_idle(void)
 void select_idle_routine(const struct cpuinfo_x86 *c)
 {
 #ifdef CONFIG_SMP
-	if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
+	if (boot_option_idle_override == IDLE_POLL && __max_threads_per_core > 1)
 		pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
 #endif
 	if (x86_idle_set() || boot_option_idle_override == IDLE_POLL)

arch/x86/kernel/smpboot.c

@@ -563,7 +563,7 @@ static void __init build_sched_topology(void)
 
 void set_cpu_sibling_map(int cpu)
 {
-	bool has_smt = smp_num_siblings > 1;
+	bool has_smt = __max_threads_per_core > 1;
 	bool has_mp = has_smt || boot_cpu_data.x86_max_cores > 1;
 	struct cpuinfo_x86 *c = &cpu_data(cpu);
 	struct cpuinfo_x86 *o;