Re: [PATCH v10 15/26] gunyah: rsc_mgr: Add platform ops on mem_lend/mem_reclaim

[Elliot Berman]

On 2/21/2023 6:51 AM, Srinivas Kandagatla wrote:
> On 14/02/2023 21:24, Elliot Berman wrote:
[snip]
> > +
> > +static struct gunyah_rm_platform_ops *rm_platform_ops;
> > +static DECLARE_RWSEM(rm_platform_ops_lock);
>
> Why do we need this read/write lock or this global rm_platform_ops here, 
> AFAIU, there will be only one instance of platform_ops per platform.
>
> This should be a core part of the gunyah and its driver early setup, 
> that should give us pretty much lock less behaviour.
>
> We should be able to determine by Hypervisor UUID that its on Qualcomm 
> platform or not, during early gunyah setup which should help us setup 
> the platfrom ops accordingly.
>
> This should also help cleanup some of the gunyah code that was added 
> futher down in this patchset.

I'm guessing the direction to take is:

  config GUNYAH
    select QCOM_SCM if ARCH_QCOM

and have vm_mgr call directly into qcom_scm driver if the UID matches?

We have an Android requirement to enable CONFIG_GUNYAH=y and 
CONFIG_QCOM_SCM=m, but it wouldn't be possible with this design. The 
platform hooks implementation allows GUNYAH and QCOM_SCM to be enabled 
without setting lower bound of the other.

- Elliot