Re: [PATCH v14 09/22] cxl: prepare memdev creation for type2

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

On 5/8/25 02:06, Alison Schofield wrote:
> On Thu, Apr 17, 2025 at 10:29:12PM +0100, alejandro.lucero-palau@amd.com wrote:
>> From: Alejandro Lucero <alucerop@amd.com>
>>
>> Current cxl core is relying on a CXL_DEVTYPE_CLASSMEM type device when
>> creating a memdev leading to problems when obtaining cxl_memdev_state
>> references from a CXL_DEVTYPE_DEVMEM type.
>>
>> Modify check for obtaining cxl_memdev_state adding CXL_DEVTYPE_DEVMEM
>> support.
>>
>> Make devm_cxl_add_memdev accessible from a accel driver.
>>
>> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
>> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
>> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>> Reviewed-by: Dave Jiang <dave.jiang@intel.com>


snip


>>   
>>   	rc = devm_add_action_or_reset(dev, remove_debugfs, dentry);
>>   	if (rc)
>> @@ -219,6 +225,13 @@ static umode_t cxl_mem_visible(struct kobject *kobj, struct attribute *a, int n)
>>   	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
>>   	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
>>   
>> +	/*
>> +	 * Avoid poison sysfs files for Type2 devices as they rely on
>> +	 * cxl_memdev_state.
>> +	 */
>> +	if (!mds)
>> +		return 0;
>> +
> The above 2 'if (!mds)' seem like indirect methods to avoid Type 2
> devices. How about:
>
> 	/* Type 2, CXL_DEVTYPE_DEVMEM, excluded from poison setup */
> 	if (cxlds->type == CXL_DEVTYPE_CLASSMEM) {
>

Hi Allison,


I forgot this one.


I think it is better to leave the current check because it makes 
explicit the problem of cxl_memdev_state being null for Type2.


Thanks

>
> snip
>