Some remote processors (in particular the modem) found in Qualcomm platforms stores configuration parameters and other data in a file system. As the remotes does not have direct storage access it needs to relay block accesses through a service running on the application CPU.
The memory is described in DeviceTree by a new reserved-memory compatible and the implementation provides the user space service a read/write interface to this chunk of memory. Bjorn Andersson (5): of/platform: Generalize /reserved-memory handling of: reserved_mem: Accessor for acquiring reserved_mem dt-binding: soc: qcom: Add binding for RFSA soc: qcom: Remote FS memory driver arm64: dts: msm8916: Mark rmtfs node as qcom,rfsa compatible .../bindings/reserved-memory/qcom,rfsa.txt | 44 ++++ arch/arm64/boot/dts/qcom/msm8916.dtsi | 3 + drivers/of/of_reserved_mem.c | 26 ++ drivers/of/platform.c | 22 +- drivers/soc/qcom/Kconfig | 8 + drivers/soc/qcom/Makefile | 1 + drivers/soc/qcom/rfsa.c | 262 +++++++++++++++++++++ include/linux/of_reserved_mem.h | 5 + 8 files changed, 365 insertions(+), 6 deletions(-) create mode 100644 Documentation/devicetree/bindings/reserved-memory/qcom,rfsa.txt create mode 100644 drivers/soc/qcom/rfsa.c -- 2.12.0
