Re: [PATCH v4 05/23] cxl: Add callback to parse the DSMAS subtables from CDAT

[Dave Jiang <dave.jiang@intel.com>]

On 4/25/23 8:44 PM, Li, Ming wrote:
> On 4/20/2023 4:21 AM, Dave Jiang wrote:
>> Provide a callback function to the CDAT parser in order to parse the Device
>> Scoped Memory Affinity Structure (DSMAS). Each DSMAS structure contains the
>> DPA range and its associated attributes in each entry. See the CDAT
>> specification for details.
>>
>> Coherent Device Attribute Table 1.03 2.1 Device Scoped memory Affinity
>> Structure (DSMAS)
>>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>>
>> ---
>> v3:
>> - Add spec section number. (Alison)
>> - Remove cast from void *. (Alison)
>> - Refactor cxl_port_probe() block. (Alison)
>> - Move CDAT parse to cxl_endpoint_port_probe()
>>
>> v2:
>> - Add DSMAS table size check. (Lukas)
>> - Use local DSMAS header for LE handling.
>> - Remove dsmas lock. (Jonathan)
>> - Fix handle size (Jonathan)
>> - Add LE to host conversion for DSMAS address and length.
>> - Make dsmas_list local
>> ---
>>   drivers/cxl/core/cdat.c |   26 ++++++++++++++++++++++++++
>>   drivers/cxl/cxl.h       |    1 +
>>   drivers/cxl/cxlpci.h    |   18 ++++++++++++++++++
>>   drivers/cxl/port.c      |   22 ++++++++++++++++++++++
>>   4 files changed, 67 insertions(+)
>>
>> diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
>> index 210f4499bddb..6f20af83a3ed 100644
>> --- a/drivers/cxl/core/cdat.c
>> +++ b/drivers/cxl/core/cdat.c
>> @@ -98,3 +98,29 @@ int cdat_table_parse_sslbis(struct cdat_header *table,
>>   	return cdat_table_parse_entries(CDAT_TYPE_SSLBIS, table, &proc);
>>   }
>>   EXPORT_SYMBOL_NS_GPL(cdat_table_parse_sslbis, CXL);
>> +
>> +int cxl_dsmas_parse_entry(struct cdat_entry_header *header, void *arg)
>> +{
>> +	struct cdat_dsmas *dsmas = (struct cdat_dsmas *)header;
>> +	struct list_head *dsmas_list = arg;
>> +	struct dsmas_entry *dent;
>> +
>> +	if (dsmas->hdr.length != sizeof(*dsmas)) {
>> +		pr_warn("Malformed DSMAS table length: (%lu:%u)\n",
>> +			 (unsigned long)sizeof(*dsmas), dsmas->hdr.length);
>> +		return -EINVAL;
>> +	}
>> +
>> +	dent = kzalloc(sizeof(*dent), GFP_KERNEL);
>> +	if (!dent)
>> +		return -ENOMEM;
>> +
>> +	dent->handle = dsmas->dsmad_handle;
>> +	dent->dpa_range.start = le64_to_cpu(dsmas->dpa_base_address);
>> +	dent->dpa_range.end = le64_to_cpu(dsmas->dpa_base_address) +
>> +			      le64_to_cpu(dsmas->dpa_length) - 1;
> 
> Hi Dave,
> 
> I saw you didn't store flags field into dent, it is not needed or missed?

Hi Ming,
I didn't have a need for it for this patch set. But I think it may be 
needed in the future for DCD. I figured when we do, we can add it.

> 
> Thanks
> Ming
> 
>