Re: [PATCH v14 16/22] cxl/region: factor out interleave ways setup

[Alejandro Lucero Palau <alucerop@amd.com>]

On 5/8/25 02:16, Alison Schofield wrote:
> On Thu, Apr 17, 2025 at 10:29:19PM +0100, alejandro.lucero-palau@amd.com wrote:
>> From: Alejandro Lucero <alucerop@amd.com>
>>
>> In preparation for kernel driven region creation, factor out a common
> Please define "kernel driven region creation".
>
> Also, please keep repeating that these changes are introduced for Type 2
> support and note whether there is any functional change to existing region
> creation path.


Ok. I'll do so.

Thanks


>
>> helper from the user-sysfs region setup for interleave ways.
>>
>> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
>> Reviewed-by: Zhi Wang <zhiw@nvidia.com>
>> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
>> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
>> ---
>>   drivers/cxl/core/region.c | 46 +++++++++++++++++++++++----------------
>>   1 file changed, 27 insertions(+), 19 deletions(-)
>
>> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
>> index 6371284283b0..095e52237516 100644
>> --- a/drivers/cxl/core/region.c
>> +++ b/drivers/cxl/core/region.c
>> @@ -464,22 +464,14 @@ static ssize_t interleave_ways_show(struct device *dev,
>>   
>>   static const struct attribute_group *get_cxl_region_target_group(void);
>>   
>> -static ssize_t interleave_ways_store(struct device *dev,
>> -				     struct device_attribute *attr,
>> -				     const char *buf, size_t len)
>> +static int set_interleave_ways(struct cxl_region *cxlr, int val)
>>   {
>> -	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev->parent);
>> +	struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(cxlr->dev.parent);
>>   	struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
>> -	struct cxl_region *cxlr = to_cxl_region(dev);
>>   	struct cxl_region_params *p = &cxlr->params;
>> -	unsigned int val, save;
>> -	int rc;
>> +	int save, rc;
>>   	u8 iw;
>>   
>> -	rc = kstrtouint(buf, 0, &val);
>> -	if (rc)
>> -		return rc;
>> -
>>   	rc = ways_to_eiw(val, &iw);
>>   	if (rc)
>>   		return rc;
>> @@ -494,20 +486,36 @@ static ssize_t interleave_ways_store(struct device *dev,
>>   		return -EINVAL;
>>   	}
>>   
>> -	rc = down_write_killable(&cxl_region_rwsem);
>> -	if (rc)
>> -		return rc;
>> -	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) {
>> -		rc = -EBUSY;
>> -		goto out;
>> -	}
>> +	lockdep_assert_held_write(&cxl_region_rwsem);
>> +	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE)
>> +		return -EBUSY;
>>   
>>   	save = p->interleave_ways;
>>   	p->interleave_ways = val;
>>   	rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group());
>>   	if (rc)
>>   		p->interleave_ways = save;
>> -out:
>> +
>> +	return rc;
>> +}
>> +
>> +static ssize_t interleave_ways_store(struct device *dev,
>> +				     struct device_attribute *attr,
>> +				     const char *buf, size_t len)
>> +{
>> +	struct cxl_region *cxlr = to_cxl_region(dev);
>> +	unsigned int val;
>> +	int rc;
>> +
>> +	rc = kstrtouint(buf, 0, &val);
>> +	if (rc)
>> +		return rc;
>> +
>> +	rc = down_write_killable(&cxl_region_rwsem);
>> +	if (rc)
>> +		return rc;
>> +
>> +	rc = set_interleave_ways(cxlr, val);
>>   	up_write(&cxl_region_rwsem);
>>   	if (rc)
>>   		return rc;
>> -- 
>> 2.34.1
>>
>>