[PATCH v1 00/14] tee: optee: add dynamic shared memory support

[Volodymyr Babchuk]

From: Volodymyr Babchuk <vlad.babchuk@xxxxxxxxx>

Changes from v1:

 * Added support for 16K and 64K pages.
 * Elaborated commit messages
 * More minor changes are described in corresponding patches.

While this patches are necessary for use OP-TEE in virualized environment,
they are not sufficient. Stuart Yoder was right, when proposed to make
static SHM optional. But that would be a breaking change, because this
will render unusable older client libraries and supplicants.

Also, as Mark Rutland pointed, OP-TEE virtualization will need support
from hypervisor side.

Anyways, those patches allowed me to call OP-TEE from XEN's Dom0 without
remapping static SHM region into Dom0 userspace.

Also, this patches allow me to share quite big buffers (I tried to
use three 2M buffers at a time). This is imposible with static SHM,
because static SHM on most platforms is only 2M.

Thanks to Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> and
Mark Rutland <mark.rutland@xxxxxxx> for reviewing this patch series.

---
v1 cover letter:
This patch series enables dynamic shared memory support in the TEE
subsystem as a whole and in OP-TEE in particular.

Global Platform TEE specification [1] allows client applications
to register part of own memory as a shared buffer between
application and TEE. This allows fast zero-copy communication between
TEE and REE. But current implementation of TEE in Linux does not support
this feature.

Also, current implementation of OP-TEE transport uses fixed size
pre-shared buffer for all communications with OP-TEE OS. This is okay
in the most use cases. But this prevents use of OP-TEE in virtualized
environments, because:
 a) We can't share the same buffer between different virtual machines
 b) Physically contiguous memory as seen by VM can be non-contiguous
    in reality (and as seen by OP-TEE OS) due to second stage of
    MMU translation.
 c) Size of this pre-shared buffer is limited.

So, first part of this patch series adds generic register/unregister
interface to tee subsystem. Next patches add necessary features
into OP-TEE driver, so it can use not only static pre-shared buffer,
but whole RAM to communicate with OP-TEE OS.

[1] https://www.globalplatform.org/specificationsdevice.asp

Jens Wiklander (2):
  tee: flexible shared memory  pool creation
  tee: add register user memory

Volodymyr Babchuk (12):
  tee: shm: add accessors for buffer size and page offset
  tee: shm: add page accessor functions
  tee: optee: Update protocol definitions
  tee: optee: add page list manipulation functions
  tee: optee: add shared buffer registration functions
  tee: optee: add registered shared parameters handling
  tee: optee: add registered buffers handling into RPC calls
  tee: optee: store OP-TEE capabilities in private data
  tee: optee: add optee-specific shared pool implementation
  tee: optee: enable dynamic SHM support
  tee: use reference counting for tee_context
  tee: shm: inline tee_shm_get_id()

 drivers/tee/optee/Makefile        |   1 +
 drivers/tee/optee/call.c          | 179 +++++++++++++++++++++++++++++-
 drivers/tee/optee/core.c          | 152 +++++++++++++++++++------
 drivers/tee/optee/optee_msg.h     |  38 ++++++-
 drivers/tee/optee/optee_private.h |  27 ++++-
 drivers/tee/optee/optee_smc.h     |   7 ++
 drivers/tee/optee/rpc.c           |  77 +++++++++++--
 drivers/tee/optee/shm_pool.c      |  75 +++++++++++++
 drivers/tee/optee/shm_pool.h      |  23 ++++
 drivers/tee/tee_core.c            |  81 ++++++++++++--
 drivers/tee/tee_private.h         |  60 +---------
 drivers/tee/tee_shm.c             | 227 +++++++++++++++++++++++++++++++-------
 drivers/tee/tee_shm_pool.c        | 165 ++++++++++++++++-----------
 include/linux/tee_drv.h           | 183 +++++++++++++++++++++++++++++-
 include/uapi/linux/tee.h          |  30 +++++
 15 files changed, 1104 insertions(+), 221 deletions(-)
 create mode 100644 drivers/tee/optee/shm_pool.c
 create mode 100644 drivers/tee/optee/shm_pool.h

-- 
2.7.4