On 09/10/2024 16:04, Shiraz Hashim wrote: > On Mon, Oct 07, 2024 at 06:25:01PM +0200, Dmitry Baryshkov wrote: >> On Mon, 7 Oct 2024 at 17:35, Mukesh Ojha <quic_mojha@xxxxxxxxxxx> wrote: >>> >>> On Sun, Oct 06, 2024 at 10:38:01PM +0300, Dmitry Baryshkov wrote: >>>> On Sat, Oct 05, 2024 at 02:53:54AM GMT, Mukesh Ojha wrote: >>>>> From: Shiraz Hashim <quic_shashim@xxxxxxxxxxx> >>>>> >>>>> Qualcomm’s PAS implementation for remote processors only supports a >>>>> single stage of IOMMU translation and is presently managed by the >>>>> Qualcomm EL2 hypervisor (QHEE) if it is present. In the absence of QHEE, >>>>> such as with a KVM hypervisor, IOMMU translations need to be set up by >>>>> the KVM host. Remoteproc needs carveout memory region and its resource >>>>> (device memory) permissions to be set before it comes up, and this >>>>> information is presently available statically with QHEE. >>>>> >>>>> In the absence of QHEE, the boot firmware needs to overlay this >>>>> information based on SoCs running with either QHEE or a KVM hypervisor >>>>> (CPUs booted in EL2). >>>>> >>>>> The qcom,devmem property provides IOMMU devmem translation information >>>>> intended for non-QHEE based systems. >>>>> >>>>> Signed-off-by: Shiraz Hashim <quic_shashim@xxxxxxxxxxx> >>>>> Co-Developed-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx> >>>>> Signed-off-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx> >>>>> --- >>>>> .../bindings/remoteproc/qcom,pas-common.yaml | 42 +++++++++++++++++++ >>>>> .../bindings/remoteproc/qcom,sa8775p-pas.yaml | 20 +++++++++ >>>>> 2 files changed, 62 insertions(+) >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml b/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml >>>>> index 63a82e7a8bf8..068e177ad934 100644 >>>>> --- a/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml >>>>> +++ b/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml >>>>> @@ -52,6 +52,48 @@ properties: >>>>> minItems: 1 >>>>> maxItems: 3 >>>>> >>>>> + iommus: >>>>> + maxItems: 1 >>>>> + >>>>> + qcom,devmem: >>>>> + $ref: /schemas/types.yaml#/definitions/uint32-matrix >>>>> + description: >>>>> + Qualcomm’s PAS implementation for remote processors only supports a >>>>> + single stage of IOMMU translation and is presently managed by the >>>>> + Qualcomm EL2 hypervisor (QHEE) if it is present. In the absence of QHEE, >>>>> + such as with a KVM hypervisor, IOMMU translations need to be set up by >>>>> + the KVM host. Remoteproc might need some device resources and related >>>>> + access permissions to be set before it comes up, and this information is >>>>> + presently available statically with QHEE. >>>>> + >>>>> + In the absence of QHEE, the boot firmware needs to overlay this >>>>> + information based on SoCs running with either QHEE or a KVM hypervisor >>>>> + (CPUs booted in EL2). >>>>> + >>>>> + The qcom,devmem property provides IOMMU devmem translation information >>>>> + intended for non-QHEE based systems. It is an array of u32 values >>>>> + describing the device memory regions for which IOMMU translations need to >>>>> + be set up before bringing up Remoteproc. This array consists of 4-tuples >>>>> + defining the device address, physical address, size, and attribute flags >>>>> + with which it has to be mapped. >>>> >>>> I'd expect that this kind of information is hardware-dependent. As such >>>> it can go to the driver itself, rather than the device tree. The driver >>>> can use compatible string to select the correct table. >>>> >>> >>> IIUC, are you saying that to move this into driver file and override the >>> compatible string via overlay ? >> >> Ideally we should live without compat overrides. On the other hand, >> sc7180 and sc7280 provide an example of doing exactly that. > > I am not sure if there can arise a case where updated adsp firmware > for particular board(s) may require additional access. > > Having it in device tree adds a convenience to deal with such > variance. > That's a downstream argument... Just look at the downstream DTS. Everything, even software properties, can be added to DT, right? Best regards, Krzysztof
