Re: [RESEND PATCH v5 02/12] firmware: qcom: scm: enable the TZ mem allocator

[Bartosz Golaszewski]

On Tue, 21 Nov 2023 at 07:35, Prasad Sodagudi <quic_psodagud@xxxxxxxxxxx> wrote:
>
>
> On 11/20/2023 5:21 AM, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> >
> > Select the TrustZone memory allocator in Kconfig and create a pool of
> > memory shareable with the TrustZone when probing the SCM driver.
> >
> > This will allow a gradual conversion of all relevant SCM calls to using
> > the dedicated allocator.
> >
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> > Reviewed-by: Andrew Halaney <ahalaney@xxxxxxxxxx>
> > Tested-by: Andrew Halaney <ahalaney@xxxxxxxxxx> # sc8280xp-lenovo-thinkpad-x13s
> > ---
> >   drivers/firmware/qcom/Kconfig    |  1 +
> >   drivers/firmware/qcom/qcom_scm.c | 16 ++++++++++++++++
> >   2 files changed, 17 insertions(+)
> >
> > diff --git a/drivers/firmware/qcom/Kconfig b/drivers/firmware/qcom/Kconfig
> > index b80269a28224..237da40de832 100644
> > --- a/drivers/firmware/qcom/Kconfig
> > +++ b/drivers/firmware/qcom/Kconfig
> > @@ -7,6 +7,7 @@
> >   menu "Qualcomm firmware drivers"
> >
> >   config QCOM_SCM
> > +     select QCOM_TZMEM
> >       tristate
> >
> >   config QCOM_TZMEM
> > diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
> > index 520de9b5633a..0d4c028be0c1 100644
> > --- a/drivers/firmware/qcom/qcom_scm.c
> > +++ b/drivers/firmware/qcom/qcom_scm.c
> > @@ -8,8 +8,10 @@
> >   #include <linux/completion.h>
> >   #include <linux/cpumask.h>
> >   #include <linux/dma-mapping.h>
> > +#include <linux/err.h>
> >   #include <linux/export.h>
> >   #include <linux/firmware/qcom/qcom_scm.h>
> > +#include <linux/firmware/qcom/qcom_tzmem.h>
> >   #include <linux/init.h>
> >   #include <linux/interconnect.h>
> >   #include <linux/interrupt.h>
> > @@ -20,9 +22,11 @@
> >   #include <linux/of_platform.h>
> >   #include <linux/platform_device.h>
> >   #include <linux/reset-controller.h>
> > +#include <linux/sizes.h>
> >   #include <linux/types.h>
> >
> >   #include "qcom_scm.h"
> > +#include "qcom_tzmem.h"
> >
> >   static bool download_mode = IS_ENABLED(CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT);
> >   module_param(download_mode, bool, 0);
> > @@ -41,6 +45,8 @@ struct qcom_scm {
> >       int scm_vote_count;
> >
> >       u64 dload_mode_addr;
> > +
> > +     struct qcom_tzmem_pool *mempool;
> >   };
> >
> >   struct qcom_scm_current_perm_info {
> > @@ -1887,6 +1893,16 @@ static int qcom_scm_probe(struct platform_device *pdev)
> >       if (of_property_read_bool(pdev->dev.of_node, "qcom,sdi-enabled"))
> >               qcom_scm_disable_sdi();
> >
> > +     ret = qcom_tzmem_enable(__scm->dev);
> > +     if (ret)
> > +             return dev_err_probe(__scm->dev, ret,
> > +                                  "Failed to enable the TrustZone memory allocator\n");
>
> Based on my knowledge shmbridge is supported from sm8250 SoC in the
> firmware.
>
> sdm845 and couple of other targets may not have support shmbridge
> support and probe will be fail for these targets right?
>

We check the availability of the SHM Bridge calls on the platform at
run-time before enabling it. We'll simply fall-back to not using SHM
bridge in this case.

Bart

> > +
> > +     __scm->mempool = devm_qcom_tzmem_pool_new(__scm->dev, SZ_256K);
> > +     if (IS_ERR(__scm->mempool))
> > +             return dev_err_probe(__scm->dev, PTR_ERR(__scm->mempool),
> > +                                  "Failed to create the SCM memory pool\n");
> > +
> >       /*
> >        * Initialize the QSEECOM interface.
> >        *