* About * The Qualcomm SDM845 SoC has a separate SLPI (Sensor Low Power Island) DSP for sensors connected to the SoC which is responsible for exposing sensors to userspace, power saving, and other features. While sensors are connected to GPIOs of the SoC, they cannot be used because the hypervisor blocks direct access to the sensors, thus the DSP must be used to access any sensor on this SoC. The SLPI DSP uses a GLink edge (dsps) to communicate with the host and has a FastRPC interface to load files from the host filesystem such as sensor configuration files. The FastRPC interface does not use regular FastRPC Compute Banks but instead uses an allocated CMA region through which communication happens. * Changes * This patchseries add support to the FastRPC for assigning a coherent memory region to a DSP via the hypervisor with the correct permissions. This is necessary to support the SLPI found in the Qualcomm SDM845 SoC which does not have dedicated FastRPC Compute Banks, in contrast to newer SoCs, but uses a memory region instead when allocating buffers. * Related patches * 1. Remoteproc changes to support the SLPI DSP in SDM845: https://lore.kernel.org/linux-remoteproc/20230325132117.19733-1-me@xxxxxxxxxxxxxxxxx/ 2. DTS changes (v1): https://lore.kernel.org/linux-devicetree/20230325135114.21688-1-me@xxxxxxxxxxxxxxxxx/ This serie does not depend on any serie, but all of them are necessary to enable the feature in the end. * Changelog * Changes in v2: - Removed double blank lines - Dropped dt-bindings property as it is not needed for driver behavior - Add additional patch to allocate buffers via CMA memory for DSPs without dedicated FastRPC Compute Banks. Kind regards, Dylan Van Assche Dylan Van Assche (2): misc: fastrpc: support complete DMA pool access to the DSP misc: fastrpc: use coherent pool for untranslated Compute Banks drivers/misc/fastrpc.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) -- 2.39.2
