Re: [PATCH 13/19] arm64: cpu_ops: Introduce get_secondary_cpu_ops()

[Jinjie Ruan <ruanjinjie@huawei.com>]

在 2026/9/8 0:40, Will Deacon 写道:
> Introduce get_secondary_cpu_ops() to retrieve a pointer to the
> 'cpu_operations' structure for the non-boot CPUs and use it instead of
> get_cpu_ops() where we are dealing with secondary CPUs.
> 
> This is a pre-requisite for enabling parallel CPU bring-up.
> 
> Signed-off-by: Will Deacon <will@kernel.org>
> ---
>  arch/arm64/include/asm/cpu_ops.h |  1 +
>  arch/arm64/kernel/cpu_ops.c      |  5 +++++
>  arch/arm64/kernel/smp.c          | 19 +++++++------------
>  3 files changed, 13 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h
> index a444c8915e88..cd298a8710d8 100644
> --- a/arch/arm64/include/asm/cpu_ops.h
> +++ b/arch/arm64/include/asm/cpu_ops.h
> @@ -48,6 +48,7 @@ struct cpu_operations {
>  
>  int __init init_cpu_ops(int cpu);
>  extern const struct cpu_operations *get_cpu_ops(int cpu);
> +extern const struct cpu_operations *get_secondary_cpu_ops(void);
>  
>  static inline void __init init_bootcpu_ops(void)
>  {
> diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
> index eacfb88a0c0c..7d183ca31dc8 100644
> --- a/arch/arm64/kernel/cpu_ops.c
> +++ b/arch/arm64/kernel/cpu_ops.c
> @@ -127,3 +127,8 @@ const struct cpu_operations *get_cpu_ops(int cpu)
>  
>  	return NULL;
>  }
> +
> +const struct cpu_operations *get_secondary_cpu_ops(void)
> +{
> +	return cpu_ops;
> +}
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index c5e9d5d5e003..2e98a92eb764 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -100,7 +100,7 @@ static inline int op_cpu_kill(unsigned int cpu)
>   */
>  static int boot_secondary(unsigned int cpu, struct task_struct *idle)
>  {
> -	const struct cpu_operations *ops = get_cpu_ops(cpu);
> +	const struct cpu_operations *ops = get_secondary_cpu_ops();
>  
>  	if (ops->cpu_boot)
>  		return ops->cpu_boot(cpu);
> @@ -220,7 +220,7 @@ asmlinkage notrace void secondary_start_kernel(void)
>  	 */
>  	check_local_cpu_capabilities();
>  
> -	ops = get_cpu_ops(cpu);
> +	ops = get_secondary_cpu_ops();
>  	if (ops->cpu_postboot)
>  		ops->cpu_postboot();
>  
> @@ -327,7 +327,7 @@ int __cpu_disable(void)
>  
>  static int op_cpu_kill(unsigned int cpu)
>  {
> -	const struct cpu_operations *ops = get_cpu_ops(cpu);
> +	const struct cpu_operations *ops = get_secondary_cpu_ops();
>  
>  	/*
>  	 * If we have no means of synchronising with the dying CPU, then assume
> @@ -368,7 +368,7 @@ void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)
>  void __noreturn cpu_die(void)
>  {
>  	unsigned int cpu = smp_processor_id();
> -	const struct cpu_operations *ops = get_cpu_ops(cpu);
> +	const struct cpu_operations *ops = get_secondary_cpu_ops();
>  
>  	idle_task_exit();
>  
> @@ -492,7 +492,7 @@ static int __init smp_cpu_setup(int cpu)
>  	if (init_cpu_ops(cpu))
>  		return -ENODEV;
>  
> -	ops = get_cpu_ops(cpu);
> +	ops = get_secondary_cpu_ops();
>  	if (ops->cpu_init(cpu))
>  		return -ENODEV;
>  
> @@ -776,7 +776,7 @@ void __init smp_init_cpus(void)
>  
>  void __init smp_prepare_cpus(unsigned int max_cpus)
>  {
> -	const struct cpu_operations *ops;
> +	const struct cpu_operations *ops = get_secondary_cpu_ops();
>  	unsigned int cpu;
>  	int err;
>  
> @@ -802,10 +802,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
>  		if (cpu == 0)
>  			continue;
>  
> -		ops = get_cpu_ops(cpu);
> -		if (!ops)
> -			continue;
> -

Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>

>  		err = ops->cpu_prepare(cpu);
>  		if (err)
>  			continue;
> @@ -1341,8 +1337,7 @@ bool smp_crash_stop_failed(void)
>  static bool have_cpu_die(void)
>  {
>  #ifdef CONFIG_HOTPLUG_CPU
> -	int any_cpu = raw_smp_processor_id();
> -	const struct cpu_operations *ops = get_cpu_ops(any_cpu);
> +	const struct cpu_operations *ops = get_secondary_cpu_ops();
>  
>  	if (ops && ops->cpu_die)
>  		return true;