On Mon, Oct 14, 2024 at 1:19 PM Kuldeep Singh <quic_kuldsing@xxxxxxxxxxx> wrote:
>
> From: Qingqing Zhou <quic_qqzhou@xxxxxxxxxxx>
>
> When enabling SHM bridge, QTEE returns 0 and sets error 4 in result to
> qcom_scm for unsupported platforms. Currently, tzmem interprets this as
> an unknown error rather than recognizing it as an unsupported platform.
>
> Error log:
> [ 0.177224] qcom_scm firmware:scm: error (____ptrval____): Failed to enable the TrustZone memory allocator
> [ 0.177244] qcom_scm firmware:scm: probe with driver qcom_scm failed with error 4
>
> To address this, modify the function call qcom_scm_shm_bridge_enable()
> to remap result to indicate an unsupported error. This way, tzmem will
> correctly identify it as an unsupported platform case instead of
> reporting it as an error.
>
> Fixes: 178e19c0df1b ("firmware: qcom: scm: add support for SHM bridge operations")
> Signed-off-by: Qingqing Zhou <quic_qqzhou@xxxxxxxxxxx>
> Co-developed-by: Kuldeep Singh <quic_kuldsing@xxxxxxxxxxx>
> Signed-off-by: Kuldeep Singh <quic_kuldsing@xxxxxxxxxxx>
> ---
> drivers/firmware/qcom/qcom_scm.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
> index 10986cb11ec0..0df81a9ed438 100644
> --- a/drivers/firmware/qcom/qcom_scm.c
> +++ b/drivers/firmware/qcom/qcom_scm.c
> @@ -112,6 +112,7 @@ enum qcom_scm_qseecom_tz_cmd_info {
> };
>
> #define QSEECOM_MAX_APP_NAME_SIZE 64
> +#define SHMBRIDGE_RESULT_NOTSUPP 4
>
> /* Each bit configures cold/warm boot address for one of the 4 CPUs */
> static const u8 qcom_scm_cpu_cold_bits[QCOM_SCM_BOOT_MAX_CPUS] = {
> @@ -1361,6 +1362,8 @@ EXPORT_SYMBOL_GPL(qcom_scm_lmh_dcvsh_available);
>
> int qcom_scm_shm_bridge_enable(void)
> {
> + int ret;
> +
> struct qcom_scm_desc desc = {
> .svc = QCOM_SCM_SVC_MP,
> .cmd = QCOM_SCM_MP_SHM_BRIDGE_ENABLE,
> @@ -1373,7 +1376,15 @@ int qcom_scm_shm_bridge_enable(void)
> QCOM_SCM_MP_SHM_BRIDGE_ENABLE))
> return -EOPNOTSUPP;
>
> - return qcom_scm_call(__scm->dev, &desc, &res) ?: res.result[0];
> + ret = qcom_scm_call(__scm->dev, &desc, &res);
> +
> + if (ret)
> + return ret;
> +
> + if (res.result[0] == SHMBRIDGE_RESULT_NOTSUPP)
> + return -EOPNOTSUPP;
> +
> + return res.result[0];
> }
> EXPORT_SYMBOL_GPL(qcom_scm_shm_bridge_enable);
>
> --
> 2.34.1
>
>
The patch looks correct to me and like something that should go upstream.
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
That being said, this doesn't seem to address any of the issues that
we saw with SHM Bridge and it still leads to a crash on sc8180x. :(
Bart
