Re: [PATCH v4 2/7] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Krzysztof Kozlowski <krzk@kernel.org>]

On 05/09/2024 09:50, Krzysztof Kozlowski wrote:
> On 05/09/2024 09:15, Jan Kiszka wrote:
>> On 05.09.24 08:53, Krzysztof Kozlowski wrote:
>>> On 05/09/2024 08:40, Jan Kiszka wrote:
>>>> On 05.09.24 08:32, Krzysztof Kozlowski wrote:
>>>>> On Wed, Sep 04, 2024 at 12:00:11PM +0200, Jan Kiszka wrote:
>>>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>>>
>>>>>> The PVU on the AM65 SoC is capable of restricting DMA from PCIe devices
>>>>>> to specific regions of host memory. Add the optional property
>>>>>> "memory-regions" to point to such regions of memory when PVU is used.
>>>>>>
>>>>>> Since the PVU deals with system physical addresses, utilizing the PVU
>>>>>> with PCIe devices also requires setting up the VMAP registers to map the
>>>>>> Requester ID of the PCIe device to the CBA Virtual ID, which in turn is
>>>>>> mapped to the system physical address. Hence, describe the VMAP
>>>>>> registers which are optionally unless the PVU shall used for PCIe.
>>>>>>
>>>>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>>>>> ---
>>>>>> CC: Lorenzo Pieralisi <lpieralisi@kernel.org>
>>>>>> CC: "Krzysztof Wilczyński" <kw@linux.com>
>>>>>> CC: Bjorn Helgaas <bhelgaas@google.com>
>>>>>> CC: linux-pci@vger.kernel.org
>>>>>> ---
>>>>>>  .../bindings/pci/ti,am65-pci-host.yaml        | 52 ++++++++++++++-----
>>>>>>  1 file changed, 40 insertions(+), 12 deletions(-)
>>>>>>
>>>>>> diff --git a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>>>>>> index 0a9d10532cc8..d8182bad92de 100644
>>>>>> --- a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>>>>>> +++ b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>>>>>> @@ -19,16 +19,6 @@ properties:
>>>>>>        - ti,am654-pcie-rc
>>>>>>        - ti,keystone-pcie
>>>>>>  
>>>>>> -  reg:
>>>>>> -    maxItems: 4
>>>>>> -
>>>>>> -  reg-names:
>>>>>> -    items:
>>>>>> -      - const: app
>>>>>> -      - const: dbics
>>>>>> -      - const: config
>>>>>> -      - const: atu
>>>>>
>>>>>
>>>>> Nothing improved here.
>>>>
>>>> Yes, explained the background to you. Sorry, if you do not address my
>>>> replies, I'm lost with your feedback.
>>>
>>> My magic ball could not figure out the problem, so did not provide the
>>> answer.
>>>
>>> I gave you the exact code which illustrates how to do it. If you do it
>>> that way: it works. If you do it other way: it might not work. However
>>
>> The link you provided was unfortunately not self-explanatory because if 
>> I - apparently - do it like that example, I'm getting the errors below.
>>
>>> without seeing anything, magic ball was silent, so I am not
>>> participating in game: would you be so kind to give more information so
>>> I won't waste my day in asking what is wrong.
>>
>> With my patch:
>>
>> # make ... dtbs_check
>>   DTC [C] arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic.dtb
>>   DTC [C] arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic-pg2.dtb
>>   DTC [C] arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dtb
>>   DTC [C] arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-m2.dtb
>>   OVL [C] arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-m2-bkey-ekey-pcie.dtb
>>   OVL [C] arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-m2-bkey-usb3.dtb
>>   DTC [C] arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-pg2.dtb
>>   DTC [C] arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-sm.dtb
>>   DTC [C] arch/arm64/boot/dts/ti/k3-am654-base-board.dtb
>>
>> With this revert on top:
>>
>> diff --git a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> index d8182bad92de..dd753dae24c6 100644
>> --- a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> +++ b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> @@ -19,6 +19,16 @@ properties:
>>        - ti,am654-pcie-rc
>>        - ti,keystone-pcie
>>  
>> +  reg:
>> +    maxItems: 4
>> +
>> +  reg-names:
>> +    items:
>> +      - const: app
>> +      - const: dbics
>> +      - const: config
>> +      - const: atu
> 
> There is nothing like that in that example.
> https://elixir.bootlin.com/linux/v6.8/source/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml#L44
> 
>> +
>>    interrupts:
>>      maxItems: 1
>>  
>> @@ -104,18 +114,6 @@ then:
>>      - msi-map
>>      - num-viewport
>>  
>> -else:
>> -  properties:
>> -    reg:
>> -      maxItems: 4
>> -
>> -    reg-names:
>> -      items:
>> -        - const: app
>> -        - const: dbics
>> -        - const: config
>> -        - const: atu
> 
> Neither this.
> 
> Each case MUST be covered, look:
> https://elixir.bootlin.com/linux/v6.8/source/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml#L191

Actually your case fits better another example from UFS, so take that one:

https://elixir.bootlin.com/linux/v6.11-rc6/source/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml#L39

Best regards,
Krzysztof