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

["Li, Ming4" <ming4.li@intel.com>]

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.