On Mon, Jun 01, 2020 at 06:06:43PM +0300, Maxim Uvarov 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@xxxxxxxxxx>
> Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
Why do you mean by duplicate sysfs entries?
> ---
> Documentation/ABI/testing/sysfs-bus-optee-devices | 8 ++++++++
> MAINTAINERS | 1 +
> drivers/tee/optee/device.c | 6 +++---
> 3 files changed, 12 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@xxxxxxxxxxxxxxxx
> +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@xxxxxxxxxx>
> L: tee-dev@xxxxxxxxxxxxxxxx
> 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..ed3d1ddfa52b 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 +75,7 @@ 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);
> + dev_set_name(&optee_device->dev, "optee-ta-%pUl", device_uuid);
This code is and already was broken. If dev_set_name() returns -ENOMEM,
the name will be a null pointer.
Also, I don't get how you can just swap the name without potentially
breaking the backwards compatiblity towards the user space.
/Jarkko
