Re: [PATCH v2 11/15] cxl: make region type based on endpoint type

Alejandro Lucero Palau
2024-07-16T08:13:29Z

On 7/16/24 08:14, Li, Ming4 wrote:
> On 7/16/2024 1:28 AM, alejandro.lucero-palau@amd.com wrote:
>> From: Alejandro Lucero <alucerop@amd.com>
>>
>> Current code is expecting Type3 or CXL_DECODER_HOSTONLYMEM devices only.
>> Suport for Type2 implies region type needs to be based on the endpoint
>> type instead.
>>
>> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
>> ---
>> drivers/cxl/core/region.c | 14 +++++++++-----
>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
>> index ca464bfef77b..5cc71b8868bc 100644
>> --- a/drivers/cxl/core/region.c
>> +++ b/drivers/cxl/core/region.c
>> @@ -2645,7 +2645,8 @@ static ssize_t create_ram_region_show(struct device *dev,
>> }
>>
>> static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd,
>> - enum cxl_decoder_mode mode, int id)
>> + enum cxl_decoder_mode mode, int id,
>> + enum cxl_decoder_type target_type)
>> {
>> int rc;
>>
>> @@ -2667,7 +2668,7 @@ static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd,
>> return ERR_PTR(-EBUSY);
>> }
>>
>> - return devm_cxl_add_region(cxlrd, id, mode, CXL_DECODER_HOSTONLYMEM);
>> + return devm_cxl_add_region(cxlrd, id, mode, target_type);
>> }
>>
>> static ssize_t create_pmem_region_store(struct device *dev,
>> @@ -2682,7 +2683,8 @@ static ssize_t create_pmem_region_store(struct device *dev,
>> if (rc != 1)
>> return -EINVAL;
>>
>> - cxlr = __create_region(cxlrd, CXL_DECODER_PMEM, id);
>> + cxlr = __create_region(cxlrd, CXL_DECODER_PMEM, id,
>> + CXL_DECODER_HOSTONLYMEM);
>> if (IS_ERR(cxlr))
>> return PTR_ERR(cxlr);
>>
>> @@ -2702,7 +2704,8 @@ static ssize_t create_ram_region_store(struct device *dev,
>> if (rc != 1)
>> return -EINVAL;
>>
>> - cxlr = __create_region(cxlrd, CXL_DECODER_RAM, id);
>> + cxlr = __create_region(cxlrd, CXL_DECODER_RAM, id,
>> + CXL_DECODER_HOSTONLYMEM);
>> if (IS_ERR(cxlr))
>> return PTR_ERR(cxlr);
>>
>> @@ -3364,7 +3367,8 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd,
>>
>> do {
>> cxlr = __create_region(cxlrd, cxled->mode,
>> - atomic_read(&cxlrd->region_id));
>> + atomic_read(&cxlrd->region_id),
>> + cxled->cxld.target_type);
>> } while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY);
>>
>> if (IS_ERR(cxlr)) {
> I think that one more check between the type of root decoder and endpoint decoder is necessary in this case. Currently, root decoder type is hard coded to CXL_DECODER_HOSTONLYMEM, but it should be CXL_DECODER_DEVMEM or CXL_DECODER_HOSTONLYMEM based on cfmws->restrictions.
>

I think you are completely right.

I will work on this looking also for other implications.

Thanks

>