Reenable kernel login method for kernel TEE client API

The kernel TEE login method was accidentally disabled previously when
enabling a few other login methods, so fix that here.

* tag 'tee-fix-for-v5.10' of git://git.linaro.org:/people/jens.wiklander/linux-tee:
  tee: client UUID: Skip REE kernel login method as well

Link: https://lore.kernel.org/r/20201013070918.GA3328976@jade
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Since the addition of session's client UUID generation via commit [1],
login via REE kernel method was disallowed. So fix that via passing
nill UUID in case of TEE_IOCTL_LOGIN_REE_KERNEL method as well.

Fixes: e33bcbab16d1 ("tee: add support for session's client UUID generation") [1]
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

Simplify tee_device_register() and friends

Uses cdev_device_add() instead of the cdev_add() device_add()
combination.

Initializes dev->groups instead of direct calls to sysfs_create_group()
and friends.

* tag 'tee-dev-cleanup-for-v5.10' of git://git.linaro.org:/people/jens.wiklander/linux-tee:
  tee: avoid explicit sysfs_create/delete_group by initialising dev->groups
  tee: replace cdev_add + device_add with cdev_device_add

Link: https://lore.kernel.org/r/20200918144130.GB1219771@jade
Signed-off-by: Olof Johansson <olof@lixom.net>

If the dev->groups is initialised, the sysfs group is created as part
of device_add call. There is no need to call sysfs_create/delete_group
explicitly.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

Commit 233ed09d7fda ("chardev: add helper function to register char devs
with a struct device") added a helper function 'cdev_device_add'.

Make use of cdev_device_add in tee_device_register to replace cdev_add
and device_add. Since cdev_device_add takes care of setting the
kobj->parent, drop explicit initialisation in tee_device_alloc.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

TEE Client introduce a new capability "TEE_GEN_CAP_MEMREF_NULL"
to handle the support of the shared memory buffer with a NULL pointer.

This capability depends on TEE Capabilities and driver support.
Driver and TEE exchange capabilities at driver initialization.

Signed-off-by: Michael Whitfield <michael.whitfield@nxp.com>
Signed-off-by: Cedric Neveux <cedric.neveux@nxp.com>
Reviewed-by: Joakim Bech <joakim.bech@linaro.org>
Tested-by: Joakim Bech <joakim.bech@linaro.org> (QEMU)
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

Adds utility function in TEE subsystem for client UUID generation. This
function is also used in the optee driver.

* tag 'tee-login-for-5.8' of git://git.linaro.org/people/jens.wiklander/linux-tee:
  tee: optee: Add support for session login client UUID generation
  tee: add support for session's client UUID generation

Link: https://lore.kernel.org/r/20200512131243.GA10028@jade
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

TEE Client API defines that from user space only information needed for
specified login operations is group identifier for group based logins.

REE kernel is expected to formulate trustworthy client UUID and pass that
to TEE environment. REE kernel is required to verify that provided group
identifier for group based logins matches calling processes group
memberships.

TEE specification only defines that the information passed from REE
environment to TEE environment is encoded into on UUID.

In order to guarantee trustworthiness of client UUID user space is not
allowed to freely pass client UUID.

UUIDv5 form is used encode variable amount of information needed for
different login types.

Signed-off-by: Vesa Jääskeläinen <vesa.jaaskelainen@vaisala.com>
[jw: remove unused variable application_id]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

There are use-cases where user-space shouldn't be allowed to communicate
directly with a TEE device which is dedicated to provide a specific
service for a kernel client. So add a private login method for kernel
clients and disallow user-space to open-session using GP implementation
defined login method range: (0x80000000 - 0xBFFFFFFF).

Reviewed-by: Jerome Forissier <jerome@forissier.org>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

Removes list_shm from struct tee_context since the linked list isn't used
any longer.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>