tee: optee: Fix kernel panic caused by incorrect error handling

The error path while failing to register devices on the TEE bus has a
bug leading to kernel panic as follows:

[ 15.398930] Unable to handle kernel paging request at virtual address ffff07ed00626d7c
[ 15.406913] Mem abort info:
[ 15.409722] ESR = 0x0000000096000005
[ 15.413490] EC = 0x25: DABT (current EL), IL = 32 bits
[ 15.418814] SET = 0, FnV = 0
[ 15.421878] EA = 0, S1PTW = 0
[ 15.425031] FSC = 0x05: level 1 translation fault
[ 15.429922] Data abort info:
[ 15.432813] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
[ 15.438310] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 15.443372] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 15.448697] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000d9e3e000
[ 15.455413] [ffff07ed00626d7c] pgd=1800000bffdf9003, p4d=1800000bffdf9003, pud=0000000000000000
[ 15.464146] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP

Commit 7269cba53d90 ("tee: optee: Fix supplicant based device enumeration")
lead to the introduction of this bug. So fix it appropriately.

Reported-by: Mikko Rapeli <mikko.rapeli@linaro.org>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218542
Fixes: 7269cba53d90 ("tee: optee: Fix supplicant based device enumeration")
Cc: stable@vger.kernel.org
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

tee: optee: Fix supplicant based device enumeration

Currently supplicant dependent optee device enumeration only registers
devices whenever tee-supplicant is invoked for the first time. But it
forgets to remove devices when tee-supplicant daemon stops running and
closes its context gracefully. This leads to following error for fTPM
driver during reboot/shutdown:

[ 73.466791] tpm tpm0: ftpm_tee_tpm_op_send: SUBMIT_COMMAND invoke error: 0xffff3024

Fix this by adding an attribute for supplicant dependent devices so that
the user-space service can detect and detach supplicant devices before
closing the supplicant:

$ for dev in /sys/bus/tee/devices/*; do if [[ -f "$dev/need_supplicant" && -f "$dev/driver/unbind" ]]; \
then echo $(basename "$dev") > $dev/driver/unbind; fi done

Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Closes: https://github.com/OP-TEE/optee_os/issues/6094
Fixes: 5f178bb71e3a ("optee: enable support for multi-stage bus enumeration")
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Jerome Forissier <jerome.forissier@linaro.org>
[jw: fixed up Date documentation]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

tee: optee: fix possible memory leak in optee_register_device()

If device_register() returns error in optee_register_device(),
the name allocated by dev_set_name() need be freed. As comment
of device_register() says, it should use put_device() to give
up the reference in the error path. So fix this by calling
put_device(), then the name can be freed in kobject_cleanup(),
and optee_device is freed in optee_release_device().

Fixes: c3fa24af9244 ("tee: optee: add TEE bus device enumeration support")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

tee: replace tee_shm_alloc()

tee_shm_alloc() is replaced by three new functions,

tee_shm_alloc_user_buf() - for user mode allocations, replacing passing
the flags TEE_SHM_MAPPED | TEE_SHM_DMA_BUF

tee_shm_alloc_kernel_buf() - for kernel mode allocations, slightly
optimized compared to using the flags TEE_SHM_MAPPED | TEE_SHM_DMA_BUF.

tee_shm_alloc_priv_buf() - primarily for TEE driver internal use.

This also makes the interface easier to use as we can get rid of the
somewhat hard to use flags parameter.

The TEE subsystem and the TEE drivers are updated to use the new
functions instead.

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

tee: optee: Fix missing devices unregister during optee_remove

When OP-TEE driver is built as a module, OP-TEE client devices
registered on TEE bus during probe should be unregistered during
optee_remove. So implement optee_unregister_devices() accordingly.

Fixes: c3fa24af9244 ("tee: optee: add TEE bus device enumeration support")
Reported-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

tee: optee: Use UUID API for exporting the UUID

There is export_uuid() function which exports uuid_t to the u8 array.
Use it instead of open coding variant.

This allows to hide the uuid_t internals.

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

optee: enable support for multi-stage bus enumeration

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>

optee: use uuid for sysfs driver entry

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>

tee: optee: Fix unsigned comparison with less than zero

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>

tee: optee: Initialize some structs using memset instead of braces

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>

tee: optee: add TEE bus device enumeration support

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>