Commit 97e17c08 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'smp-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull CPU hotplug updates from Thomas Gleixner:

 - Prepare the core for supporting parallel hotplug on loongarch

 - A small set of cleanups and enhancements

* tag 'smp-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Mark smp_prepare_boot_cpu() __init
  cpu: Fix W=1 build kernel-doc warning
  cpu/hotplug: Provide weak fallback for arch_cpuhp_init_parallel_bringup()
  cpu/hotplug: Make HOTPLUG_PARALLEL independent of HOTPLUG_SMT
parents a430d95c 1d070854

arch/mips/kernel/smp.c

+1 −1
Original line number Diff line number Diff line
@@ -439,7 +439,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus) 
}



/* preload SMP state for boot cpu */

void smp_prepare_boot_cpu(void)

void __init smp_prepare_boot_cpu(void)

{

	if (mp_ops->prepare_boot_cpu)

		mp_ops->prepare_boot_cpu();

arch/powerpc/kernel/smp.c

+1 −1
Original line number Diff line number Diff line
@@ -1166,7 +1166,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus) 
	cpu_smt_set_num_threads(num_threads, threads_per_core);

}



void smp_prepare_boot_cpu(void)

void __init smp_prepare_boot_cpu(void)

{

	BUG_ON(smp_processor_id() != boot_cpuid);

#ifdef CONFIG_PPC64

include/linux/smp.h

+1 −1
Original line number Diff line number Diff line
@@ -109,7 +109,7 @@ static inline void on_each_cpu_cond(smp_cond_func_t cond_func, 
 * Architecture specific boot CPU setup.  Defined as empty weak function in

 * init/main.c. Architectures can override it.

 */

void smp_prepare_boot_cpu(void);

void __init smp_prepare_boot_cpu(void);



#ifdef CONFIG_SMP

kernel/cpu.c

+17 −3
Original line number Diff line number Diff line
@@ -1808,6 +1808,7 @@ static int __init parallel_bringup_parse_param(char *arg) 
}

early_param("cpuhp.parallel", parallel_bringup_parse_param);



#ifdef CONFIG_HOTPLUG_SMT

static inline bool cpuhp_smt_aware(void)

{

	return cpu_smt_max_threads > 1;
@@ -1817,6 +1818,21 @@ static inline const struct cpumask *cpuhp_get_primary_thread_mask(void) 
{

	return cpu_primary_thread_mask;

}

#else

static inline bool cpuhp_smt_aware(void)

{

	return false;

}

static inline const struct cpumask *cpuhp_get_primary_thread_mask(void)

{

	return cpu_none_mask;

}

#endif



bool __weak arch_cpuhp_init_parallel_bringup(void)

{

	return true;

}



/*

 * On architectures which have enabled parallel bringup this invokes all BP
@@ -2689,9 +2705,7 @@ int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) 
	return ret;

}



/**

 * Check if the core a CPU belongs to is online

 */

/* Check if the core a CPU belongs to is online */

#if !defined(topology_is_core_online)

static inline bool topology_is_core_online(unsigned int cpu)

{