Re: [PATCH 6/6] remoteproc: qcom: Enable map/unmap and SHM bridge support

[Shiraz Hashim]

On Thu, Oct 10, 2024 at 08:57:56AM +0200, neil.armstrong@xxxxxxxxxx wrote:
> On 08/10/2024 08:21, Mukesh Ojha wrote:
> > On Mon, Oct 07, 2024 at 08:22:39PM +0530, Mukesh Ojha wrote:
> > > On Mon, Oct 07, 2024 at 10:05:08AM +0200, neil.armstrong@xxxxxxxxxx wrote:
> > > > On 04/10/2024 23:23, Mukesh Ojha wrote:
> > > > > For Qualcomm SoCs runnning with Qualcomm EL2 hypervisor(QHEE), IOMMU
> > > > > translation for remote processors is managed by QHEE and if the same SoC
> > > > > run under KVM, remoteproc carveout and devmem region should be IOMMU
> > > > > mapped from Linux PAS driver before remoteproc is brought up and
> > > > > unmapped once it is tear down and apart from this, SHM bridge also need
> > > > > to set up to enable memory protection on both remoteproc meta data
> > > > > memory as well as for the carveout region.
> > > > > 
> > > > > Enable the support required to run Qualcomm remoteprocs on non-QHEE
> > > > > hypervisors.
> > > > > 
> > > > > Signed-off-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
> > > > > ---
> > > > >    drivers/remoteproc/qcom_q6v5_pas.c | 41 +++++++++++++++++++++++++++++-
> > > > >    1 file changed, 40 insertions(+), 1 deletion(-)
> > > > > 
> > > > > diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
> > > > > index ac339145e072..13bd13f1b989 100644
> > > > > --- a/drivers/remoteproc/qcom_q6v5_pas.c
> > > > > +++ b/drivers/remoteproc/qcom_q6v5_pas.c

<snip>

> > > > > +		struct of_phandle_args args;
> > > > > +
> > > > > +		ret = of_parse_phandle_with_args(pdev->dev.of_node, "iommus", "#iommu-cells", 0, &args);
> > > > > +		if (ret < 0)
> > > > > +			return ret;
> > > > > +
> > > > > +		rproc->has_iommu = true;
> > > > > +		adsp->sid = args.args[0];
> > > > > +		of_node_put(args.np);
> > > > > +		ret = adsp_devmem_init(adsp);
> > > > > +		if (ret)
> > > > > +			return ret;
> > > > 
> > > > Why don't you get this table from the firmware like presumably
> > > > QHEE does ?
> > > 
> > > Well, AFAIK, QHEE(EL2) has this information statically present
> > > and does not get it from anywhere., but will confirm this
> > > twice..
> > 
> > Double confirmed, device memory region required by remoteproc is
> > statically present with QHEE.
> 
> Right, in this case why those tables can't be embedded in the elf
> .resource_table like it's done with qcom_q6v5_adsp.c by calling
> rproc_elf_load_rsc_table() and let the remoteproc framework load the
> resource table and setup the devmem ssmu_map ?

Mainly for two reasons -

firmware images on platforms where we like to bring additional no-qhee
support do not have resource table.

QCOM PAS implementation for secure remoteproc supports single TZ call
of auth_and_rest that authenticates and brings remoteproc out of
reset. And we don't have provision to authenticate resource table
before it is used for devmem/iommu setup.

regards
Shiraz