[PATCH v4 0/4] firmware: Add support for Qualcomm UEFI Secure Application

From: Maximilian Luz
Date: Sun May 28 2023 - 19:04:20 EST

This series adds basic support for the QSEECOM interface used to
communicate with secure applications running in the TrustZone on certain
Qualcomm devices. In addition to that, it also provides a driver for
"uefisecapp", the secure application managing access to UEFI variables
on such platforms.

For a more detailed description, see the blurb of v1.

Previous versions:

- V3: https://lore.kernel.org/lkml/20230305022119.1331495-4-luzmaximilian@xxxxxxxxx/t/
- V2: https://lore.kernel.org/lkml/20230127184650.756795-1-luzmaximilian@xxxxxxxxx/
- V1: https://lore.kernel.org/lkml/20220723224949.1089973-1-luzmaximilian@xxxxxxxxx/

Patch 4 of this series depends on commit d86ff3333cb1 ("efivarfs: expose
used and total size") from the "next" branch of


Changes in v4:

- Integrate the QSEECOM interface into qcom_scm.c instead of
instantiating a custom device and requiring device-tree bindings for
it. With that, drop the respective patches exporting SCM call
functions from qcom_scm.c and the DT bindings.

- Restructure management of DMA memory and move DMA mapping entirely
into the app_send() command, removing the need for DMA handling in
app client drivers.

- Add support for EFI's query_variable_info() call.

- Move UCS-2 string helpers to lib/ucs2_string.c (introduces patch 1).

- Add fix for related cleanup-issue in qcom_scm.c (introduces patch 2).

(Refer to individual patches for more details.)

Changes in v3:

- Fix doc comment in qcom_scm.c
- Rebase on top of latest changes to qcom_scm.

Changes in v2:

- Bind the qseecom interface to a device.

- Establish a device link between the new qseecom device and the SCM
device to ensure proper PM and remove ordering.

- Remove the compatible for uefisecapp. Instead, introduce a compatible
for the qseecom device. This directly reflects ACPI tables and the
QCOM0476 device described therein, which is responsible for the
secure app / qseecom interface (i.e., the same purpose).

Client devices representing apps handled by the kernel (such as
uefisecapp) are now directly instantiated by the qseecom driver,
based on the respective platform-specific compatible.

- Rename the base name (qctree -> qseecom) to allow differentiation
between old (qseecom) and new (smcinvoke) interfaces to the trusted
execution environment. This directly reflects downstream naming by

Maximilian Luz (4):
lib/ucs2_string: Add UCS-2 strlcpy function
firmware: qcom_scm: Clear scm pointer on probe failure
firmware: qcom_scm: Add support for Qualcomm Secure Execution
Environment SCM interface
firmware: Add support for Qualcomm UEFI Secure Application

drivers/firmware/Kconfig | 33 +
drivers/firmware/Makefile | 1 +
drivers/firmware/qcom_qseecom_uefisecapp.c | 885 +++++++++++++++++++++
drivers/firmware/qcom_scm.c | 419 +++++++++-
include/linux/firmware/qcom/qcom_scm.h | 27 +
include/linux/ucs2_string.h | 1 +
lib/ucs2_string.c | 16 +
8 files changed, 1387 insertions(+), 1 deletion(-)
create mode 100644 drivers/firmware/qcom_qseecom_uefisecapp.c