Some drivers (like ftpm) can operate only after tee-supplicant
runs because of tee-supplicant provides things like storage
services (rpmb, shm).  This patch splits probe of non tee-supplicant
dependable drivers to the early stage, and after tee-supplicant run
probe other drivers.

Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Suggested-by: Sumit Garg <sumit.garg@linaro.org>
Suggested-by: Arnd Bergmann <arnd@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Acked-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

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>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

The return from the call to tee_client_invoke_func can be a
negative error code however this is being assigned to an
unsigned variable 'ret' hence the check is always false.
Fix this by making 'ret' an int.

Detected by Coccinelle ("Unsigned expression compared with zero:
ret < 0")

Fixes: c3fa24af9244 ("tee: optee: add TEE bus device enumeration support")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Clang warns:

drivers/tee/optee/device.c:39:31: warning: suggest braces around
initialization of subobject [-Wmissing-braces]
        struct tee_param param[4] = {0};
                                     ^
                                     {}
drivers/tee/optee/device.c:92:48: warning: suggest braces around
initialization of subobject [-Wmissing-braces]
        struct tee_ioctl_open_session_arg sess_arg = {0};
                                                      ^
                                                      {}
2 warnings generated.

One way to fix these warnings is to add additional braces like Clang
suggests; however, there has been a bit of push back from some
maintainers, who just prefer memset as it is unambiguous, doesn't
depend on a particular compiler version, and properly initializes all
subobjects [1][2]. Do that here so there are no more warnings.

[1]: https://lore.kernel.org/lkml/022e41c0-8465-dc7a-a45c-64187ecd9684@amd.com/
[2]: https://lore.kernel.org/lkml/20181128.215241.702406654469517539.davem@davemloft.net/

Fixes: c3fa24af9244 ("tee: optee: add TEE bus device enumeration support")
Link: https://github.com/ClangBuiltLinux/linux/issues/370
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

OP-TEE provides a pseudo TA to enumerate TAs which can act as devices/
services for TEE bus. So implement device enumeration using invoke
function: PTA_CMD_GET_DEVICES provided by pseudo TA to fetch array of
device UUIDs. Also register these enumerated devices with TEE bus as
"optee-clntX" device.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
[jw: fix optee_enumerate_devices() with no devices found]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>