• Srinivas Kandagatla's avatar
    misc: fastrpc: Add support for context Invoke method · c68cfb71
    Srinivas Kandagatla authored
    This patch adds support to compute context invoke method on the
    remote processor (DSP).
    This involves setting up the functions input and output arguments,
    input and output handles and mapping the dmabuf fd for the
    argument/handle buffers.
    
    The below diagram depicts invocation of a single method where the
    client and objects reside on different processors. An object could
    expose multiple methods which can be grouped together and referred
    to as an interface.
    
    ,--------,        ,------,  ,-----------,  ,------,        ,--------,
    |        | method |      |  |           |  |      | method |        |
    | Client |------->| Stub |->| Transport |->| Skel |------->| Object |
    |        |        |      |  |           |  |      |        |        |
    `--------`        `------`  `-----------`  `------`        `--------`
    
    Client:    Linux user mode process that initiates the remote invocation
    Stub:      Auto generated code linked in with the user mode process that
               takes care of marshaling parameters
    Transport: Involved in carrying an invocation from a client to an
               object. This involves two portions: 1) FastRPC Linux
               kernel driver that receives the remote invocation, queues
               them up and then waits for the response after signaling the
               remote side. 2) Service running on the remote side that
               dequeues the messages from the queue and dispatches them for
               processing.
    Skel:      Auto generated code that takes care of un-marshaling
               parameters
    Object:    Method implementation
    
    Most of the work is derived from various downstream Qualcomm kernels.
    Credits to various Qualcomm authors who have contributed to this code.
    Specially Tharun Kumar Merugu <mtharu@codeaurora.org>
    Co-developed-by: default avatarThierry Escande <thierry.escande@linaro.org>
    Signed-off-by: default avatarThierry Escande <thierry.escande@linaro.org>
    Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    c68cfb71
fastrpc.c 23.5 KB