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

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

On 8/20/2026 7:34 PM, Zhongqiu Han wrote:
> 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);

What if NUMA is disabled?

>>       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