On Thu, Jul 25, 2024 at 01:19:07PM GMT, Amirreza Zarrabi wrote: > > > On 7/4/2024 5:34 PM, Dmitry Baryshkov wrote: > > On Thu, 4 Jul 2024 at 00:40, Amirreza Zarrabi <quic_azarrabi@xxxxxxxxxxx> wrote: > >> > >> > >> > >> On 7/3/2024 10:13 PM, Dmitry Baryshkov wrote: > >>> On Tue, Jul 02, 2024 at 10:57:36PM GMT, Amirreza Zarrabi wrote: > >>>> Qualcomm TEE hosts Trusted Applications and Services that run in the > >>>> secure world. Access to these resources is provided using object > >>>> capabilities. A TEE client with access to the capability can invoke > >>>> the object and request a service. Similarly, TEE can request a service > >>>> from nonsecure world with object capabilities that are exported to secure > >>>> world. > >>>> > >>>> We provide qcom_tee_object which represents an object in both secure > >>>> and nonsecure world. TEE clients can invoke an instance of qcom_tee_object > >>>> to access TEE. TEE can issue a callback request to nonsecure world > >>>> by invoking an instance of qcom_tee_object in nonsecure world. > >>> > >>> Please see Documentation/process/submitting-patches.rst on how to write > >>> commit messages. > >> > >> Ack. > >> > >>> > >>>> > >>>> Any driver in nonsecure world that is interested to export a struct (or a > >>>> service object) to TEE, requires to embed an instance of qcom_tee_object in > >>>> the relevant struct and implements the dispatcher function which is called > >>>> when TEE invoked the service object. > >>>> > >>>> We also provids simplified API which implements the Qualcomm TEE transport > >>>> protocol. The implementation is independent from any services that may > >>>> reside in nonsecure world. > >>> > >>> "also" usually means that it should go to a separate commit. > >> > >> I will split this patch to multiple smaller ones. > >> > > > > [...] > > > >>> > >>>> + } in, out; > >>>> +}; > >>>> + > >>>> +int qcom_tee_object_do_invoke(struct qcom_tee_object_invoke_ctx *oic, > >>>> + struct qcom_tee_object *object, unsigned long op, struct qcom_tee_arg u[], int *result); > >>> > >>> What's the difference between a result that gets returned by the > >>> function and the result that gets retuned via the pointer? > >> > >> The function result, is local to kernel, for instance memory allocation failure, > >> or failure to issue the smc call. The result in pointer, is the remote result, > >> for instance return value from TA, or the TEE itself. > >> > >> I'll use better name, e.g. 'remote_result'? > > > > See how this is handled by other parties. For example, PSCI. If you > > have a standard set of return codes, translate them to -ESOMETHING in > > your framework and let everybody else see only the standard errors. > > > > > > I can not hide this return value, they are TA dependent. The client to a TA > needs to see it, just knowing that something has failed is not enough in > case they need to do something based on that. I can not even translate them > as they are TA related so the range is unknown. I'd say it a sad design. At least error values should be standard. -- With best wishes Dmitry
