Re: [PATCH v2] tee: optee: rework TA bus scanning code

5 Sep 2022

Hi Ilias,
Reviewed-by: Etienne Carriere etienne.carriere@linaro.org with minor comments.
On Fri, 2 Sept 2022 at 21:11, Ilias Apalodimas
ilias.apalodimas@linaro.org wrote:
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Thanks Jens
On Wed, 31 Aug 2022 at 08:59, Jens Wiklander jens.wiklander@linaro.org wrote:
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On Mon, Aug 29, 2022 at 8:34 AM Ilias Apalodimas
ilias.apalodimas@linaro.org wrote:
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Late versions of OP-TEE support a pseudo bus.  TAs that behave as
hardware blocks (e.g TPM, RNG etc) present themselves on a bus which we can
scan.  Unfortunately U-Boot doesn't support that yet. It's worth noting
that we already have a workaround for RNG.  The details are in
commit 70812bb83da6 ("tee: optee: bind rng optee driver")
So let's add a list of devices based on U-Boot Kconfig options that we will
scan until we properly implement the tee-bus functionality.
While at it change the behaviour of the tee core itself wrt to device
binding.  If some device binding fails, print a warning instead of
disabling OP-TEE.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
Reviewed-by: Jens Wiklander jens.wiklander@linaro.org
There's a typo in that patch. For the tpm to work the string needs to
be ftpm_tee instead of ftpm-tee.  I'll send a v3, shall I keep your
RB?
Cheers
/Ilias
...
Cheers,
Jens
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Changes since v1:

remove a macro and use ARRAY_SIZE directly
print a warning instead of disabling op-tee if a driver binding fails

drivers/tee/optee/core.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index a89d62aaf0b3..3cc92f09d299 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -31,6 +31,18 @@ struct optee_pdata {
        optee_invoke_fn *invoke_fn;
 };
+static const struct {

  const char *drv_name;


  const char *dev_name;



+} optee_bus_probe[] = {
+#ifdef CONFIG_RNG_OPTEE

  { "optee-rng", "optee-rng" },



By the way, prefer:
+       { .drv_name = "optee-rng", .dev_name = "optee-rng" },
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...
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+#endif
+#ifdef CONFIG_TPM2_FTPM_TEE

  { "ftpm-tee", "ftpm-tee" },



+#endif
+};



struct rpc_param {
        u32     a0;
        u32     a1;
@@ -643,7 +655,7 @@ static int optee_probe(struct udevice *dev)
        struct optee_pdata *pdata = dev_get_plat(dev);
        u32 sec_caps;
        struct udevice *child;

  int ret;




  int ret, i;

  if (!is_optee_api(pdata->invoke_fn)) {
          dev_err(dev, "OP-TEE api uid mismatch\n");



@@ -672,10 +684,13 @@ static int optee_probe(struct udevice *dev)
         * in U-Boot, the discovery of TA on the TEE bus is not supported:
         * only bind the drivers associated to the supported OP-TEE TA
         */

  if (IS_ENABLED(CONFIG_RNG_OPTEE)) {


          ret = device_bind_driver(dev, "optee-rng", "optee-rng", &child);





  for (i = 0; i < ARRAY_SIZE(optee_bus_probe); i++) {


          ret = device_bind_driver(dev, optee_bus_probe[i].drv_name,


                                   optee_bus_probe[i].dev_name, &child);



Can drop child here. NULL is fine.
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...
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            if (ret)


                  return ret;




                  dev_warn(dev, "Failed to bind device %s\n",


                           optee_bus_probe[i].dev_name);
  }

  return 0;



--
2.34.1

    