Re: [PATCH v4 00/15] arm64: qcom: add and enable SHM Bridge support

From: Andrew Halaney
Date: Fri Oct 13 2023 - 11:30:36 EST


On Fri, Oct 13, 2023 at 01:48:28PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
>
> This is pretty much another full rewrite of the SHM Bridge support
> series. After more on- and off-list discussions I think this time it
> will be close to the final thing though.
>
> We've established the need for using separate pools for SCM and QSEECOM
> as well as the upcoming scminvoke driver.
>
> It's also become clear that in order to be future-proof, the new
> allocator must be an abstraction layer of a higher level as the SHM
> Bridge will not be the only memory protection mechanism that we'll see
> upstream. Hence the rename to TrustZone Memory rather than SCM Memory
> allocator.
>
> Also to that end: the new allocator is its own module now and provides a
> Kconfig choice menu for selecting the mode of operation (currently
> default and SHM Bridge).
>
> Due to a high divergence from v2, I dropped all tags except for
> patch 1/15 which didn't change.
>
> Tested on sm8550 and sa8775p with the Inline Crypto Engine and
> remoteproc.

I took this for a spin on my x13s with SHM bridge enabled and don't see
any issues in the usecases that exercises. Also running on a debug
kernel with no warnings, etc.

Tested-by: Andrew Halaney <ahalaney@xxxxxxxxxx> # sc8280xp-lenovo-thinkpad-x13s
>
> v3 -> v4:
> - include linux/sizes.h for SZ_X macros
> - use dedicated RCU APIs to dereference radix tree slots
> - fix kerneldocs
> - fix the comment in patch 14/15: it's the hypervisor, not the TrustZone
> that creates the SHM bridge
>
> v2 -> v3:
> - restore pool management and use separate pools for different users
> - don't use the new allocator in qcom_scm_pas_init_image() as the
> TrustZone will create an SHM bridge for us here
> - rewrite the entire series again for most part
>
> v1 -> v2:
> - too many changes to list, it's a complete rewrite as explained above
>
> Bartosz Golaszewski (15):
> firmware: qcom: move Qualcomm code into its own directory
> firmware: qcom: scm: add a missing forward declaration for struct
> device
> firmware: qcom: scm: remove unneeded 'extern' specifiers
> firmware: qcom: add a dedicated TrustZone buffer allocator
> firmware: qcom: scm: enable the TZ mem allocator
> firmware: qcom: scm: smc: switch to using the SCM allocator
> firmware: qcom: scm: make qcom_scm_assign_mem() use the TZ allocator
> firmware: qcom: scm: make qcom_scm_ice_set_key() use the TZ allocator
> firmware: qcom: scm: make qcom_scm_lmh_dcvsh() use the TZ allocator
> firmware: qcom: scm: make qcom_scm_qseecom_app_get_id() use the TZ
> allocator
> firmware: qcom: qseecom: convert to using the TZ allocator
> firmware: qcom: scm: add support for SHM bridge operations
> firmware: qcom: tzmem: enable SHM Bridge support
> firmware: qcom: scm: clarify the comment in qcom_scm_pas_init_image()
> arm64: defconfig: enable SHM Bridge support for the TZ memory
> allocator
>
> MAINTAINERS | 4 +-
> arch/arm64/configs/defconfig | 1 +
> drivers/firmware/Kconfig | 48 +--
> drivers/firmware/Makefile | 5 +-
> drivers/firmware/qcom/Kconfig | 86 +++++
> drivers/firmware/qcom/Makefile | 10 +
> drivers/firmware/{ => qcom}/qcom_qseecom.c | 0
> .../{ => qcom}/qcom_qseecom_uefisecapp.c | 261 +++++--------
> drivers/firmware/{ => qcom}/qcom_scm-legacy.c | 0
> drivers/firmware/{ => qcom}/qcom_scm-smc.c | 28 +-
> drivers/firmware/{ => qcom}/qcom_scm.c | 179 +++++----
> drivers/firmware/{ => qcom}/qcom_scm.h | 21 +-
> drivers/firmware/qcom/qcom_tzmem.c | 365 ++++++++++++++++++
> drivers/firmware/qcom/qcom_tzmem.h | 13 +
> include/linux/firmware/qcom/qcom_qseecom.h | 4 +-
> include/linux/firmware/qcom/qcom_scm.h | 6 +
> include/linux/firmware/qcom/qcom_tzmem.h | 28 ++
> 17 files changed, 746 insertions(+), 313 deletions(-)
> create mode 100644 drivers/firmware/qcom/Kconfig
> create mode 100644 drivers/firmware/qcom/Makefile
> rename drivers/firmware/{ => qcom}/qcom_qseecom.c (100%)
> rename drivers/firmware/{ => qcom}/qcom_qseecom_uefisecapp.c (84%)
> rename drivers/firmware/{ => qcom}/qcom_scm-legacy.c (100%)
> rename drivers/firmware/{ => qcom}/qcom_scm-smc.c (91%)
> rename drivers/firmware/{ => qcom}/qcom_scm.c (93%)
> rename drivers/firmware/{ => qcom}/qcom_scm.h (88%)
> create mode 100644 drivers/firmware/qcom/qcom_tzmem.c
> create mode 100644 drivers/firmware/qcom/qcom_tzmem.h
> create mode 100644 include/linux/firmware/qcom/qcom_tzmem.h
>
> --
> 2.39.2
>