[PATCH v5 2/2] firmware: arm_scmi: Add qcom smc/hvc transport support

Sudeep Holla sudeep.holla at arm.com
Mon Oct 9 12:08:00 PDT 2023


On Mon, Oct 09, 2023 at 10:49:44AM -0700, Nikunj Kela wrote:
> 
> On 10/9/2023 8:29 AM, Sudeep Holla wrote:
> > On Mon, Oct 09, 2023 at 07:59:08AM -0700, Nikunj Kela wrote:
> > > On 10/9/2023 7:47 AM, Sudeep Holla wrote:
> > > > On Fri, Oct 06, 2023 at 09:42:06AM -0700, Nikunj Kela wrote:
> > > > > This change adds the support for SCMI message exchange on Qualcomm
> > > > > virtual platforms.
> > > > > 
> > > > > The hypervisor associates an object-id also known as capability-id
> > > > > with each smc/hvc doorbell object. The capability-id is used to
> > > > > identify the doorbell from the VM's capability namespace, similar
> > > > > to a file-descriptor.
> > > > > 
> > > > > The hypervisor, in addition to the function-id, expects the capability-id
> > > > > to be passed in x1 register when SMC/HVC call is invoked.
> > > > > 
> > > > > The capability-id is allocated by the hypervisor on bootup and is stored in
> > > > > the shmem region by the firmware before starting Linux.
> > > > > 
> > > > Since you are happy to move to signed value, I assume you are happy to loose
> > > > upper half of the range values ?
> > > > 
> > > > Anyways after Bjorn pointed out inconsistency, I am thinking of moving
> > > > all the values to unsigned long to work with both 32bit and 64bit.
> > > > 
> > > > Does the below delta on top of this patch works for you and makes sense?
> > > This looks good to me. Will do some testing and float v6 with the changes
> > > you suggested below. Thanks
> > > 
> > Please refer or use the patch from [1] when reposting. I rebased on my
> > patch[2] that I posted few minutes back. I am trying to finalise the branch
> > and send PR in next couple of days, so please test and post sooner. Sorry
> > for the rush.
> 
> Validated the patch from [1] below on Qualcomm ARM64 virtual platform using
> SMC64 convention. Thanks!
>

Thanks, since I have patched a bit, it is better if you post them so that
we have a link for the exact patch on the list. Just pick up the patches
from the branch[1] and post them as v6 with a change log so that all the
details are captured for reference purposes.

-- 
Regards,
Sudeep

[1] https://git.kernel.org/sudeep.holla/h/for-next/scmi/updates
[2] https://lore.kernel.org/r/20231009152049.1428872-1-sudeep.holla@arm.com



More information about the linux-arm-kernel mailing list