Re: [net-next,v2,01/10] soc: ti: K2G: enhancement to support QMSS in NSS

[Murali Karicheri]

Hi Grygorii,

Thanks for reviewing this!

On 03/28/2018 03:01 PM, Grygorii Strashko wrote:
> Hi Murali,
> 
> On 03/27/2018 11:31 AM, Murali Karicheri wrote:
>> Navigator Subsystem (NSS) available on K2G SoC has a cut down
>> version of QMSS with less number of queues, internal linking ram
>> with lesser number of buffers etc.  It doesn't have status and
>> explicit push register space as in QMSS available on other K2 SoCs.
>> So define reg indices specific to QMSS on K2G. This patch introduces
>> "keystone-navigator-qmss-l" compatibility to identify QMSS on
>> K2G NSS (QMSS Lite) and to customize the dts handling code. Per
>> Device manual, descriptors with index less than or equal to
>> regions0_size is in region 0 in the case of QMSS where as for
>> QMSS Lite, descriptors with index less than regions0_size is in
>> region 0. So update the size accordingly in the regions0_size bits
>> of the linking ram size 0 register.
>>
>> Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx>
>> Signed-off-by: WingMan Kwok <w-kwok2@xxxxxx>
>> ---
>>   .../bindings/soc/ti/keystone-navigator-qmss.txt    |  7 ++
>>   drivers/soc/ti/knav_qmss.h                         |  6 ++
>>   drivers/soc/ti/knav_qmss_queue.c                   | 90 ++++++++++++++++------
>>   3 files changed, 81 insertions(+), 22 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt b/Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt
>> index 77cd42c..1b0878a 100644
>> --- a/Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt
>> +++ b/Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt
>> @@ -18,6 +18,7 @@ pool management.
>>   
>>   Required properties:
>>   - compatible	: Must be "ti,keystone-navigator-qmss";
>> +		: Must be "ti,keystone-navigator-qmss-l" for NSS Lite
> 
> 
> I think, It will be more accurate to add K2G specific compat string
> like "ti,66ak2g-navss-qm":
> 
> compatible = "ti,66ak2g-navss-qm", "ti,keystone-navigator-qmss";
> 
> because 66ak2g TRM doesn't mention "Navss light" and this Navss version is used
> only in 66ak2g Soc. As result, 66ak2g Navss QM is subset of of keystone 2 Navss QM 
> which should be defined in DT by adding more specific compat string in addition
> to generic one.  
> 

As I have mentioned in the commit description, it is not a subset of the K2
registers. There are some differences that makes it not compatible with K2 QMSS.
See my description, 

>>It doesn't have status and explicit push register space as in QMSS available on
>>other K2 SoCs.

And also

>> Per Device manual, descriptors with index less than or equal to
>> regions0_size is in region 0 in the case of QMSS where as for
>> QMSS Lite, descriptors with index less than regions0_size is in
>> region 0. So update the size accordingly in the regions0_size bits
>> of the linking ram size 0 register

So will have to use a specific compatible = "ti,66ak2g-navss-qm" for this QM IMO.

Murali
> 
>>   - clocks	: phandle to the reference clock for this device.
>>   - queue-range	: <start number> total range of queue numbers for the device.
>>   - linkram0	: <address size> for internal link ram, where size is the total
>> @@ -39,6 +40,12 @@ Required properties:
>>   			  - Descriptor memory setup region.
>>   			  - Queue Management/Queue Proxy region for queue Push.
>>   			  - Queue Management/Queue Proxy region for queue Pop.
>> +
>> +For NSS lite, following QMSS reg indexes are used in that order
> 
> For 66AK2G NAVSS QM..
> 
>> +			  - Queue Peek region.
>> +			  - Queue configuration region.
>> +			  - Queue Management/Queue Proxy region for queue Push/Pop.
>> +
>>   - queue-pools	: child node classifying the queue ranges into pools.
>>   		  Queue ranges are grouped into 3 type of pools:
>>   		  - qpend	    : pool of qpend(interruptible) queues
>> diff --git a/drivers/soc/ti/knav_qmss.h b/drivers/soc/ti/knav_qmss.h
>> index 905b974..5fa1ce6 100644
>> --- a/drivers/soc/ti/knav_qmss.h
>> +++ b/drivers/soc/ti/knav_qmss.h
>> @@ -292,6 +292,11 @@ struct knav_queue {
>>   	struct list_head		list;
>>   };
>>   
>> +enum qmss_version {
>> +	QMSS,
>> +	QMSS_LITE,
> 
> QMSS_66AK2G
> 
>> +};
>> +
>>   struct knav_device {
>>   	struct device				*dev;
>>   	unsigned				base_id;
>> @@ -305,6 +310,7 @@ struct knav_device {
>>   	struct list_head			pools;
>>   	struct list_head			pdsps;
>>   	struct list_head			qmgrs;
>> +	enum qmss_version			version;
>>   };
>>   
> 
> [...]
> 
>>   }
>>   
>> +/* Match table for of_platform binding */
>> +static const struct of_device_id keystone_qmss_of_match[] = {
>> +	{
>> +		.compatible = "ti,keystone-navigator-qmss",
> 
> 		.data	= (void *)QMSS,
> 
>> +	},
>> +	{
>> +		.compatible = "ti,keystone-navigator-qmss-l",
>> +		.data	= (void *)QMSS_LITE,
>> +	},
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, keystone_qmss_of_match);
>> +
>>   static int knav_queue_probe(struct platform_device *pdev)
>>   {
>>   	struct device_node *node = pdev->dev.of_node;
>>   	struct device_node *qmgrs, *queue_pools, *regions, *pdsps;
>> +	const struct of_device_id *match;
>>   	struct device *dev = &pdev->dev;
>>   	u32 temp[2];
>>   	int ret;
>> @@ -1700,6 +1749,10 @@ static int knav_queue_probe(struct platform_device *pdev)
>>   		return -ENOMEM;
>>   	}
>>   
>> +	match = of_match_device(of_match_ptr(keystone_qmss_of_match), dev);
>> +	if (match && match->data)
>> +		kdev->version = QMSS_LITE;
> 
> 	if (match)
> 		kdev->version = match->data;
> 	else
> 		error?
> [...]
> 


-- 
Murali Karicheri
Linux Kernel, Keystone