Re: [PATCH v23 20/22] cxl: Avoid dax creation for accelerators

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

On 2/11/26 22:10, Cheatham, Benjamin wrote:
> On 2/1/2026 9:54 AM, alejandro.lucero-palau@amd.com wrote:
>> From: Alejandro Lucero <alucerop@amd.com>
>>
>> By definition a type2 cxl device will use the host managed memory for
>> specific functionality, therefore it should not be available to other
>> uses.
>>
>> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
>> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>> Reviewed-by: Davidlohr Bueso <daves@stgolabs.net>
>> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
>> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
>> ---
>>   drivers/cxl/core/region.c | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
>> index 293e63dfef22..12df717cc881 100644
>> --- a/drivers/cxl/core/region.c
>> +++ b/drivers/cxl/core/region.c
>> @@ -4441,6 +4441,13 @@ static int cxl_region_probe(struct device *dev)
>>   	if (rc)
>>   		return rc;
>>   
>> +	/*
>> +	 * HDM-D[B] (device-memory) regions have accelerator specific usage.
>> +	 * Skip device-dax registration.
>> +	 */
>> +	if (cxlr->type == CXL_DECODER_DEVMEM)
>> +		return 0;
> Minor nit: Should probably move this to be the first thing in the function. It would save
> having to acquire a lock in cxl_region_can_probe() above. Keep my reviewed-by either way,
> it's really just a minor optimization.


It makes sense. I'll do it.

Thanks


>> +
>>   	/*
>>   	 * From this point on any path that changes the region's state away from
>>   	 * CXL_CONFIG_COMMIT is also responsible for releasing the driver.