Re: [PATCH 4/6] qcom-scm: add ocmem support

[Stephen Boyd <sboyd@codeaurora.org>]

On 09/29, Rob Clark wrote:
> On Tue, Sep 29, 2015 at 5:38 PM, Stephen Boyd <sboyd@codeaurora.org> wrote:
> > On 09/29, Rob Clark wrote:
> >> diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
> >> index c1e4325..e1ac97f 100644
> >> --- a/drivers/firmware/qcom_scm-32.c
> >> +++ b/drivers/firmware/qcom_scm-32.c
> >> @@ -500,6 +500,59 @@ int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
> >>               req, req_cnt * sizeof(*req), resp, sizeof(*resp));
> >>  }
> >>
> >> +int __qcom_scm_ocmem_secure_cfg(unsigned sec_id)
> >> +{
> >> +     int ret, scm_ret = 0;
> >> +     struct msm_scm_sec_cfg {
> >
> > We've left these as anonymous structs for things like
> > qcom_scm_set_boot_addr(), maybe we should do the same here.
> >
> >> +             __le32 id;
> >> +             __le32 spare;
> >
> > Also, the iommu driver would use this API and it uses this
> > "spare" element, so perhaps this whole function should be renamed
> > to be more generic and take two values. Downstream the function
> > is called scm_restore_sec_cfg, so maybe something similar.  And
> > the service id is MP for "memory protection", so
> > QCOM_SCM_OCMEM_SECURE_SVC could be QCOM_SCM_MEMORY_PROTECTION?
> 
> heh,
> 
>     #define SCM_SVC_MP            0xC
>     #define IOMMU_SECURE_CFG    2
> 
> vs.
> 
>     #define OCMEM_SECURE_SVC_ID 12
>     #define OCMEM_SECURE_CFG_ID 0x2
> 
> that wasn't obscure at all!

:)

> 
> Maybe then there is a better name than spare?  Looks like downstream
> iommu calls it cb_num?

Yeah I think that's the only use to indicate which context bank
it is. Maybe we can have a single id configure API and a special
iommu context bank API that both funnel into the same private two
number API. Otherwise we have a bunch of callers passing 0 for
the second argument because they don't care.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
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