[PATCH 4/5] qcom-scm: add support to restore secure config

[Rob Clark]

On Mon, Oct 5, 2015 at 10:22 AM, Rob Clark <robdclark at gmail.com> wrote:
> Needed by OCMEM driver.
>
> Signed-off-by: Rob Clark <robdclark at gmail.com>
> ---

Note:  I am contemplating squashing something like this in:

----------------
diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h
index beadca4..d3f209d 100644
--- a/include/linux/qcom_scm.h
+++ b/include/linux/qcom_scm.h
@@ -32,8 +32,18 @@ extern bool qcom_scm_hdcp_available(void);
 extern int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt,
         u32 *resp);

+enum qcom_scm_sec_dev_id {
+    QCOM_SCM_MDSS_DEV_ID    = 1,
+    QCOM_SCM_OCMEM_DEV_ID    = 5,
+    QCOM_SCM_PCIE0_DEV_ID    = 11,
+    QCOM_SCM_PCIE1_DEV_ID    = 12,
+    QCOM_SCM_GFX_DEV_ID    = 18,
+    QCOM_SCM_UFS_DEV_ID    = 19,
+    QCOM_SCM_ICE_DEV_ID    = 20,
+};
+
 extern bool qcom_scm_restore_sec_config_available(void);
-extern int qcom_scm_restore_sec_config(unsigned sec_id);
+extern int qcom_scm_restore_sec_config(enum qcom_scm_sec_dev_id sec_id);
----------------

The thing I am unsure about is whether the device-id's are always
stable across different parts.  From what I can tell from
dumpster-diving the downstream kernel, there is a mix of hard-coding
dev-id in code, vs taking it out of devicetree.  But in cases where it
comes from devicetree, it seems like it is always using the same
values across different SoCs.  But I may be missing something.. and
since downstream kernel branches tend to shed support for older
generations I may not be going far enough back in time..

BR,
-R

>  drivers/firmware/qcom_scm-32.c | 20 ++++++++++++++++++++
>  drivers/firmware/qcom_scm-64.c |  5 +++++
>  drivers/firmware/qcom_scm.c    | 22 ++++++++++++++++++++++
>  drivers/firmware/qcom_scm.h    |  5 +++++
>  include/linux/qcom_scm.h       |  3 +++
>  5 files changed, 55 insertions(+)
>
> diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
> index c1e4325..a7bf6d4 100644
> --- a/drivers/firmware/qcom_scm-32.c
> +++ b/drivers/firmware/qcom_scm-32.c
> @@ -500,6 +500,26 @@ 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_restore_sec_config(u32 sec_id, u32 ctx_bank_num)
> +{
> +       int ret, scm_ret = 0;
> +       struct msm_scm_sec_cfg {
> +               __le32 id;
> +               __le32 ctx_bank_num;
> +       } cfg;
> +
> +       cfg.id = cpu_to_le32(sec_id);
> +       cfg.ctx_bank_num = cpu_to_le32(sec_id);
> +
> +       ret = qcom_scm_call(QCOM_SCM_MP_SVC, QCOM_SCM_MP_RESTORE_SEC_CFG,
> +                       &cfg, sizeof(cfg), &scm_ret, sizeof(scm_ret));
> +
> +       if (ret || scm_ret)
> +               return ret ? ret : -EINVAL;
> +
> +       return 0;
> +}
> +
>  bool __qcom_scm_pas_supported(u32 peripheral)
>  {
>         __le32 out;
> diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
> index e64fd92..7329cf0f 100644
> --- a/drivers/firmware/qcom_scm-64.c
> +++ b/drivers/firmware/qcom_scm-64.c
> @@ -62,6 +62,11 @@ int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
>         return -ENOTSUPP;
>  }
>
> +int __qcom_scm_restore_sec_config(u32 sec_id, u32 ctx_bank_num)
> +{
> +       return -ENOTSUPP;
> +}
> +
>  bool __qcom_scm_pas_supported(u32 peripheral)
>  {
>         return false;
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index 39082c1..8f43c0b 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -154,6 +154,28 @@ int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
>  EXPORT_SYMBOL(qcom_scm_hdcp_req);
>
>  /**
> + * qcom_scm_restore_sec_config_available() - Check if secure environment
> + * supports restore security config interface.
> + *
> + * Return true if restore-cfg interface is supported, false if not.
> + */
> +bool qcom_scm_restore_sec_config_available(void)
> +{
> +       return __qcom_scm_is_call_available(QCOM_SCM_MP_SVC,
> +                       QCOM_SCM_MP_RESTORE_SEC_CFG);
> +}
> +EXPORT_SYMBOL(qcom_scm_restore_sec_config_available);
> +
> +/**
> + * qcom_scm_restore_sec_config() - call restore-cfg interface
> + */
> +int qcom_scm_restore_sec_config(unsigned sec_id)
> +{
> +       return __qcom_scm_restore_sec_config(sec_id, 0);
> +}
> +EXPORT_SYMBOL(qcom_scm_restore_sec_config);
> +
> +/**
>   * qcom_scm_pas_supported() - Check if the peripheral authentication service is
>   *                           available for the given peripherial
>   * @peripheral:        peripheral id
> diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
> index 220d19c..3085616 100644
> --- a/drivers/firmware/qcom_scm.h
> +++ b/drivers/firmware/qcom_scm.h
> @@ -36,6 +36,11 @@ extern int __qcom_scm_is_call_available(u32 svc_id, u32 cmd_id);
>  extern int __qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt,
>                 u32 *resp);
>
> +#define QCOM_SCM_MP_SVC                        0xc
> +#define QCOM_SCM_MP_RESTORE_SEC_CFG            0x2
> +
> +extern int __qcom_scm_restore_sec_config(u32 sec_id, u32 ctx_bank_num);
> +
>  #define QCOM_SCM_SVC_PIL               0x2
>  #define QCOM_SCM_PAS_INIT_IMAGE_CMD    0x1
>  #define QCOM_SCM_PAS_MEM_SETUP_CMD     0x2
> diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h
> index e407c0a..7be3d91 100644
> --- a/include/linux/qcom_scm.h
> +++ b/include/linux/qcom_scm.h
> @@ -32,6 +32,9 @@ extern bool qcom_scm_hdcp_available(void);
>  extern int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt,
>                 u32 *resp);
>
> +extern bool qcom_scm_restore_sec_config_available(void);
> +extern int qcom_scm_restore_sec_config(unsigned sec_id);
> +
>  extern bool qcom_scm_pas_supported(u32 peripheral);
>  extern int qcom_scm_pas_init_image(u32 peripheral, const void *metadata, size_t size);
>  extern int qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size);
> --
> 2.4.3
>