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. regards Shiraz
