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

[Krzysztof Kozlowski <krzk@kernel.org>]

On 05/09/2024 09:15, 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

> -
>  unevaluatedProperties: false
>  
>  examples:
> 
> # make ... dtbs_check
>   DTC [C] arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic.dtb
> .../arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic.dtb: pcie@5500000: reg: [[0, 89128960, 0, 4096], [0, 89133056, 0, 4096], [0, 268435456, 0, 8192], [0, 89153536, 0, 4096], [0, 42991616, 0, 4096], [0, 43024384, 0, 4096]] is too long
>         from schema $id: http://devicetree.org/schemas/pci/ti,am65-pci-host.yaml#
> .../arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic.dtb: pcie@5500000: reg-names: ['app', 'dbics', 'config', 'atu', 'vmap_lp', 'vmap_hp'] is too long
>         from schema $id: http://devicetree.org/schemas/pci/ti,am65-pci-host.yaml#
> .../arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic.dtb: pcie@5600000: reg: [[0, 90177536, 0, 4096], [0, 90181632, 0, 4096], [0, 402653184, 0, 8192], [0, 90202112, 0, 4096], [0, 43057152, 0, 4096], [0, 43089920, 0, 4096]] is too long
>         from schema $id: http://devicetree.org/schemas/pci/ti,am65-pci-host.yaml#
> .../arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic.dtb: pcie@5600000: reg-names: ['app', 'dbics', 'config', 'atu', 'vmap_lp', 'vmap_hp'] is too long
>         from schema $id: http://devicetree.org/schemas/pci/ti,am65-pci-host.yaml#
>   DTC [C] arch/arm64/boot/dts/ti/k3-am6528-iot2050-basic-pg2.dtb
> ...
> 
> 
> Which magic dtschema spell am I missing to make this work like you 
> suggest?

follow the example. You do it entirely different so you have different
result. Code works deterministically.

Best regards,
Krzysztof