Re: [PATCH 3/5] cpufreq: loongson3: Replace per-package mutex with per-node

[Zhongqiu Han <zhongqiu.han@oss.qualcomm.com>]

On 8/18/2026 8:39 PM, Huacai Chen wrote:
> Our server productions (e.g. Loongson-3D6000/3E6000) can have multiple
> nodes in one package and SMC mailboxes are also per-node. So replace the
> per-package mutex with per-node one.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Hongliang Wang <wanghongliang@loongson.cn>
> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> ---
>   drivers/cpufreq/loongson3_cpufreq.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/cpufreq/loongson3_cpufreq.c b/drivers/cpufreq/loongson3_cpufreq.c
> index 630f679aa739..e3cd78a5ab18 100644
> --- a/drivers/cpufreq/loongson3_cpufreq.c
> +++ b/drivers/cpufreq/loongson3_cpufreq.c
> @@ -169,7 +169,7 @@ struct loongson3_freq_data {
>   	struct cpufreq_frequency_table table[];
>   };
>   
> -static struct mutex cpufreq_mutex[MAX_PACKAGES];
> +static struct mutex cpufreq_mutex[MAX_NUMNODES];
>   static struct cpufreq_driver loongson3_cpufreq_driver;
>   static DEFINE_PER_CPU(struct loongson3_freq_data *, freq_data);
>   
> @@ -177,14 +177,14 @@ static inline int do_service_request(u32 id, u32 info, u32 cmd, u32 val, u32 ext
>   {
>   	int retries;
>   	unsigned int cpu = raw_smp_processor_id();
> -	unsigned int package = cpu_data[cpu].package;
> +	unsigned int nid = cpu_to_node(cpu);
>   	union smc_message msg, last;
>   
> -	mutex_lock(&cpufreq_mutex[package]);
> +	mutex_lock(&cpufreq_mutex[nid]);
>   
>   	last.value = iocsr_read32(LOONGARCH_IOCSR_SMCMBX);
>   	if (!last.complete) {
> -		mutex_unlock(&cpufreq_mutex[package]);
> +		mutex_unlock(&cpufreq_mutex[nid]);
>   		return -EPERM;
>   	}
>   
> @@ -208,11 +208,11 @@ static inline int do_service_request(u32 id, u32 info, u32 cmd, u32 val, u32 ext
>   	}
>   
>   	if (!msg.complete || msg.cmd != CMD_OK) {
> -		mutex_unlock(&cpufreq_mutex[package]);
> +		mutex_unlock(&cpufreq_mutex[nid]);
>   		return -EPERM;
>   	}
>   
> -	mutex_unlock(&cpufreq_mutex[package]);
> +	mutex_unlock(&cpufreq_mutex[nid]);

An optimization independent of this patch: considering to use
guard(mutex)(xxx.lock)

>   
>   	return msg.val;
>   }
> @@ -337,7 +337,7 @@ static int loongson3_cpufreq_probe(struct platform_device *pdev)
>   {
>   	int i, ret;
>   
> -	for (i = 0; i < MAX_PACKAGES; i++) {
> +	for (i = 0; i < MAX_NUMNODES; i++) {
>   		ret = devm_mutex_init(&pdev->dev, &cpufreq_mutex[i]);
>   		if (ret)
>   			return ret;


-- 
Thx and BRs,
Zhongqiu Han