Re: [Tee-dev] [PATCHv8 1/3] optee: use uuid for sysfs driver entry

Hi Maxim,

On Thu, 4 Jun 2020 at 23:28, Maxim Uvarov maxim.uvarov@linaro.org wrote:

With the evolving use-cases for TEE bus, now it's required to support multi-stage enumeration process. But using a simple index doesn't suffice this requirement and instead leads to duplicate sysfs entries. So instead switch to use more informative device UUID for sysfs entry like: /sys/bus/tee/devices/optee-ta-<uuid>

Signed-off-by: Maxim Uvarov maxim.uvarov@linaro.org Reviewed-by: Sumit Garg sumit.garg@linaro.org

---

Documentation/ABI/testing/sysfs-bus-optee-devices | 8 ++++++++ MAINTAINERS | 1 + drivers/tee/optee/device.c | 9 ++++++--- 3 files changed, 15 insertions(+), 3 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-optee-devices

diff --git a/Documentation/ABI/testing/sysfs-bus-optee-devices b/Documentation/ABI/testing/sysfs-bus-optee-devices new file mode 100644 index 000000000000..0ae04ae5374a --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-optee-devices @@ -0,0 +1,8 @@ +What: /sys/bus/tee/devices/optee-ta-<uuid>/ +Date: May 2020 +KernelVersion 5.7 +Contact: tee-dev@lists.linaro.org +Description:

•           OP-TEE bus provides reference to registered drivers under this directory. The <uuid>
  

•           matches Trusted Application (TA) driver and corresponding TA in secure OS. Drivers
  

•           are free to create needed API under optee-ta-<uuid> directory.
  

diff --git a/MAINTAINERS b/MAINTAINERS index ecc0749810b0..6717afef2de3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12516,6 +12516,7 @@ OP-TEE DRIVER M: Jens Wiklander jens.wiklander@linaro.org L: tee-dev@lists.linaro.org S: Maintained +F: Documentation/ABI/testing/sysfs-bus-optee-devices F: drivers/tee/optee/

OP-TEE RANDOM NUMBER GENERATOR (RNG) DRIVER diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c index e3a148521ec1..23d264c8146e 100644 --- a/drivers/tee/optee/device.c +++ b/drivers/tee/optee/device.c @@ -65,7 +65,7 @@ static int get_devices(struct tee_context *ctx, u32 session, return 0; }

-static int optee_register_device(const uuid_t *device_uuid, u32 device_id) +static int optee_register_device(const uuid_t *device_uuid) { struct tee_client_device *optee_device = NULL; int rc; @@ -75,7 +75,10 @@ static int optee_register_device(const uuid_t *device_uuid, u32 device_id) return -ENOMEM;

    optee_device->dev.bus = &tee_bus_type;

•   dev_set_name(&optee_device->dev, "optee-clnt%u", device_id);
  

•   if (dev_set_name(&optee_device->dev, "optee-ta-%pUl", device_uuid)) {
  

You should be using format specifier as: "%pUb" instead of "%pUl" as UUID representation for TAs is in big endian format. See below:

# ls /sys/bus/tee/devices/ optee-ta-405b6ad9-e5c3-e321-8794-1002a5d5c61b optee-ta-71d950bc-c9d4-c442-82cb-343fb7f37896 optee-ta-e70f4af0-5d1f-9b4b-abf7-619b85b4ce8c

While UUID for fTPM TA is in big endian format: bc50d971-d4c9-42c4-82cb-343fb7f37896

Sorry that I missed it during review and noticed this while testing.

With the above fix included, I tested this series using fTPM early TA on Qemu for aarch64 and used basic random number generation test using tpm2-tools. So feel free to add:

Tested-by: Sumit Garg sumit.garg@linaro.org

-Sumit

•           kfree(optee_device);
  

•           return -ENOMEM;
  

•   }
    uuid_copy(&optee_device->id.uuid, device_uuid);
  
    rc = device_register(&optee_device->dev);
  

@@ -144,7 +147,7 @@ int optee_enumerate_devices(void) num_devices = shm_size / sizeof(uuid_t);

    for (idx = 0; idx < num_devices; idx++) {

•           rc = optee_register_device(&device_uuid[idx], idx);
  

•           rc = optee_register_device(&device_uuid[idx]);
            if (rc)
                    goto out_shm;
    }
  

-- 2.17.1