Commit Graph

13 Commits

Author SHA1 Message Date
Amirreza Zarrabi
0cbaf65c91 tee: add close_context to TEE driver operation
The tee_context can be used to manage TEE user resources, including
those allocated by the driver for the TEE on behalf of the user.
The release() callback is invoked only when all resources, such as
tee_shm, are released and there are no references to the tee_context.

When a user closes the device file, the driver should notify the
TEE to release any resources it may hold and drop the context
references. To achieve this, a close_context() callback is
introduced to initiate resource release in the TEE driver when
the device file is closed.

Relocate teedev_ctx_get, teedev_ctx_put, tee_device_get, and
tee_device_get functions to tee_core.h to make them accessible
outside the TEE subsystem.

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
Tested-by: Harshal Dev <quic_hdev@quicinc.com>
Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2025-09-15 17:34:06 +02:00
Etienne Carriere
146bf4e75e tee: new ioctl to a register tee_shm from a dmabuf file descriptor
Add a userspace API to create a tee_shm object that refers to a dmabuf
reference.

Userspace registers the dmabuf file descriptor as in a tee_shm object.
The registration is completed with a tee_shm returned file descriptor.

Userspace is free to close the dmabuf file descriptor after it has been
registered since all the resources are now held via the new tee_shm
object.

Closing the tee_shm file descriptor will eventually release all
resources used by the tee_shm object when all references are released.

The new IOCTL, TEE_IOC_SHM_REGISTER_FD, supports dmabuf references to
physically contiguous memory buffers. Dmabuf references acquired from
the TEE DMA-heap can be used as protected memory for Secure Video Path
and such use cases. It depends on the TEE and the TEE driver if dmabuf
references acquired by other means can be used.

A new tee_shm flag is added to identify tee_shm objects built from a
registered dmabuf, TEE_SHM_DMA_BUF.

Signed-off-by: Etienne Carriere <etienne.carriere@foss.st.com>
Signed-off-by: Olivier Masse <olivier.masse@nxp.com>
Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2025-09-11 11:22:29 +02:00
Jens Wiklander
c924c65f52 tee: implement protected DMA-heap
Implement DMA heap for protected DMA-buf allocation in the TEE
subsystem.

Protected memory refers to memory buffers behind a hardware enforced
firewall. It is not accessible to the kernel during normal circumstances
but rather only accessible to certain hardware IPs or CPUs executing in
higher or differently privileged mode than the kernel itself. This
interface allows to allocate and manage such protected memory buffers
via interaction with a TEE implementation.

The protected memory is allocated for a specific use-case, like Secure
Video Playback, Trusted UI, or Secure Video Recording where certain
hardware devices can access the memory.

The DMA-heaps are enabled explicitly by the TEE backend driver. The TEE
backend drivers needs to implement protected memory pool to manage the
protected memory.

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2025-09-11 11:22:20 +02:00
Sumit Garg
0439fcff30 tee: Refactor TEE subsystem header files
Since commit 25559c22ce ("tee: add kernel internal client interface"),
it has been a common include/linux/tee_drv.h header file which is shared
to hold TEE subsystem internal bits along with the APIs exposed to the
TEE client drivers. However, this practice is prone to TEE subsystem
internal APIs abuse and especially so with the new TEE implementation
drivers being added to reuse existing functionality.

In order to address this split TEE subsystem internal bits as a separate
header file: include/linux/tee_core.h which should be the one used by
TEE implementation drivers. With that include/linux/tee_drv.h lists only
APIs exposed by TEE subsystem to the TEE client drivers.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Balint Dobszay <balint.dobszay@arm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2024-04-03 09:19:31 +02:00
Yue Haibing
069969d6c5 tee: Remove unused declarations
Commit 4fb0a5eb36 ("tee: add OP-TEE driver") declared but never implemented
optee_supp_read()/optee_supp_write().
Commit 967c9cca2c ("tee: generic TEE subsystem") never implemented tee_shm_init().

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2023-09-13 08:16:24 +02:00
Jens Wiklander
056d3fed3d tee: add tee_shm_register_{user,kernel}_buf()
Adds the two new functions tee_shm_register_user_buf() and
tee_shm_register_kernel_buf() which should be used instead of the old
tee_shm_register().

This avoids having the caller supplying the flags parameter which
exposes a bit more than desired of the internals of the TEE subsystem.

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2022-02-16 07:49:41 +01:00
Jens Wiklander
d88e0493a0 tee: simplify shm pool handling
Replaces the shared memory pool based on two pools with a single pool.
The alloc() function pointer in struct tee_shm_pool_ops gets another
parameter, align. This makes it possible to make less than page aligned
allocations from the optional reserved shared memory pool while still
making user space allocations page aligned. With in practice unchanged
behaviour using only a single pool for bookkeeping.

The allocation algorithm in the static OP-TEE shared memory pool is
changed from best-fit to first-fit since only the latter supports an
alignment parameter. The best-fit algorithm was previously the default
choice and not a conscious one.

The optee and amdtee drivers are updated as needed to work with this
changed pool handling.

This also removes OPTEE_SHM_NUM_PRIV_PAGES which becomes obsolete with
this change as the private pages can be mixed with the payload pages.

The OP-TEE driver changes minimum alignment for argument struct from 8
bytes to 512 bytes. A typical OP-TEE private shm allocation is 224 bytes
(argument struct with 6 parameters, needed for open session). So with an
alignment of 512 well waste a bit more than 50%. Before this we had a
single page reserved for this so worst case usage compared to that would
be 3 pages instead of 1 page. However, this worst case only occurs if
there is a high pressure from multiple threads on secure world. All in
all this should scale up and down better than fixed boundaries.

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2022-02-16 07:49:41 +01:00
Jens Wiklander
71cc47d4cc tee: add tee_shm_alloc_user_buf()
Adds a new function tee_shm_alloc_user_buf() for user mode allocations,
replacing passing the flags TEE_SHM_MAPPED | TEE_SHM_DMA_BUF to
tee_shm_alloc().

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2022-02-16 07:49:41 +01:00
Jens Wiklander
f1bbacedb0 tee: don't assign shm id for private shms
Private shared memory object must not be referenced from user space. To
guarantee that, don't assign an id to shared memory objects which are
driver private.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2020-02-28 13:37:42 +01:00
Thomas Gleixner
9c92ab6191 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282
Based on 1 normalized pattern(s):

  this software is licensed under the terms of the gnu general public
  license version 2 as published by the free software foundation and
  may be copied distributed and modified under those terms this
  program is distributed in the hope that it will be useful but
  without any warranty without even the implied warranty of
  merchantability or fitness for a particular purpose see the gnu
  general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 285 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00
Volodymyr Babchuk
217e0250cc tee: use reference counting for tee_context
We need to ensure that tee_context is present until last
shared buffer will be freed.

Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-12-15 13:36:18 +01:00
Jens Wiklander
e2aca5d892 tee: flexible shared memory pool creation
Makes creation of shm pools more flexible by adding new more primitive
functions to allocate a shm pool. This makes it easier to add driver
specific shm pool management.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
2017-12-15 12:37:29 +01:00
Jens Wiklander
967c9cca2c tee: generic TEE subsystem
Initial patch for generic TEE subsystem.
This subsystem provides:
* Registration/un-registration of TEE drivers.
* Shared memory between normal world and secure world.
* Ioctl interface for interaction with user space.
* Sysfs implementation_id of TEE driver

A TEE (Trusted Execution Environment) driver is a driver that interfaces
with a trusted OS running in some secure environment, for example,
TrustZone on ARM cpus, or a separate secure co-processor etc.

The TEE subsystem can serve a TEE driver for a Global Platform compliant
TEE, but it's not limited to only Global Platform TEEs.

This patch builds on other similar implementations trying to solve
the same problem:
* "optee_linuxdriver" by among others
  Jean-michel DELORME<jean-michel.delorme@st.com> and
  Emmanuel MICHEL <emmanuel.michel@st.com>
* "Generic TrustZone Driver" by Javier González <javier@javigon.com>

Acked-by: Andreas Dannenberg <dannenberg@ti.com>
Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (HiKey)
Tested-by: Volodymyr Babchuk <vlad.babchuk@gmail.com> (RCAR H3)
Tested-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-03-09 15:42:33 +01:00