Open Profile for DICE is an open protocol for measured boot compatible with the Trusted Computing Group's Device Identifier Composition Engine (DICE) specification. The generated Compound Device Identifier (CDI) certificates represent the measured hardware/software combination and can be used by userspace for remote attestation and sealing. This patchset adds DeviceTree bindings for the DICE device referencing a reserved memory region containing the CDIs, and a driver that exposes the memory region to userspace via a misc device. See https://pigweed.googlesource.com/open-dice for more details. The patches are based on top of v5.17-rc1 and can also be found here: https://android-kvm.googlesource.com/linux topic/dice_v7 Changes since v6: * replace spinlock with mutex because devm_memremap can sleep * prevent write+shared mapping via mprotect/mremap * fail gracefully when no instances found * no-map required in DT bindings to ensure mem region not treated as RAM Changes since v5: * replaced 'additionalProperties' with 'unevaluatedProperties' in DT YAML Changes since v4: * registered compatible in 'reserved_mem_matches' * removed unnecessary DT node, only reserved-memory * fixed typos in comments Changes since v3: * align with semantics of read/write * fix kerneldoc warnings * fix printf format warnings Changes since v2: * renamed from 'dice' to 'open-dice' * replaced ioctls with read/write * replaced memzero_explicit with memset * allowed multiple instances * expanded Kconfig description Changes since v1: * converted to miscdevice * all mappings now write-combine to simplify semantics * removed atomic state, any attempt at exclusive access * simplified wipe, applied on ioctl, not on release * fixed ioctl return value David Brazdil (2): dt-bindings: reserved-memory: Open Profile for DICE misc: open-dice: Add driver to expose DICE data to userspace .../reserved-memory/google,open-dice.yaml | 46 ++++ drivers/misc/Kconfig | 12 + drivers/misc/Makefile | 1 + drivers/misc/open-dice.c | 208 ++++++++++++++++++ drivers/of/platform.c | 1 + 5 files changed, 268 insertions(+) create mode 100644 Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml create mode 100644 drivers/misc/open-dice.c -- 2.35.0.rc0.227.g00780c9af4-goog