[patch 44/53] x86/cpu/topology: Mop up primary thread mask handling

Thomas Gleixner
2023-08-07T13:56:03Z

The early initcall to initialize the primary thread mask is not longer
required because topology_init_possible_cpus() can mark primary threads
correctly when initializing the possible and present map as the number of
SMT threads is already determined correctly.

The XENPV workaround is not longer required because XENPV now registers
fake APIC IDs which will just work like any other enumeration.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/cpu/topology.c | 29 ++---------------------------
1 file changed, 2 insertions(+), 27 deletions(-)

--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -92,30 +92,6 @@ static void cpu_mark_primary_thread(unsi
if (smp_num_siblings == 1 || !(apicid & mask))
cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
}
-
-/*
- * Due to the utter mess of CPUID evaluation smp_num_siblings is not valid
- * during early boot. Initialize the primary thread mask before SMP
- * bringup.
- */
-static int __init smp_init_primary_thread_mask(void)
-{
- unsigned int cpu;
-
- /*
- * XEN/PV provides either none or useless topology information.
- * Pretend that all vCPUs are primary threads.
- */
- if (xen_pv_domain()) {
- cpumask_copy(&__cpu_primary_thread_mask, cpu_possible_mask);
- return 0;
- }
-
- for (cpu = 0; cpu < topo_info.nr_assigned_cpus; cpu++)
- cpu_mark_primary_thread(cpu, cpuid_to_apicid[cpu]);
- return 0;
-}
-early_initcall(smp_init_primary_thread_mask);
#else
static inline void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid) { }
#endif
@@ -161,9 +137,6 @@ static void topo_set_cpuids(unsigned int
#endif
set_cpu_possible(cpu, true);
set_cpu_present(cpu, true);
-
- if (system_state != SYSTEM_BOOTING)
- cpu_mark_primary_thread(cpu, apic_id);
}

/**
@@ -252,6 +225,7 @@ int topology_hotplug_apic(u32 apic_id, u

set_bit(apic_id, phys_cpu_present_map);
topo_set_cpuids(cpu, apic_id, acpi_id);
+ cpu_mark_primary_thread(cpu, apic_id);
return cpu;
}

@@ -422,6 +396,7 @@ void __init topology_init_possible_cpus(
if (apicid == BAD_APICID)
continue;

+ cpu_mark_primary_thread(cpu, apicid);
set_cpu_present(cpu, test_bit(apicid, phys_cpu_present_map));
}
}