[PATCH v4 0/5] misc: Add support to Qualcomm FastRPC driver

[Srinivas Kandagatla]

Thanks for reviewing the v3, here is new version addressing the
comments from v3.
This patchset adds support to Qualcomm FastRPC driver which implements
an IPC (Inter-Processor Communication) mechanism that allows for clients
to transparently make remote method invocations across processor boundaries.

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@xxxxxxxxxxxxxx>

TODO:
 - Support INIT_STATIC process
 - Support remote mmap/unmap methods.
 - Handling secure compute context banks.
 - Add secure buffer support

This patchset has been tested on DB410c(msm8916), DB820c (msm8996), SDM845
and QCS404 Qualcomm SoCs with sample apps like matrix multiply, calculator
from Hexagon SDK. You can find more info on how to test this at:
https://github.com/96boards/documentation/wiki/Dragonboard-Hexagon-DSP

Changes since v3(https://patchwork.kernel.org/cover/10763343/) :
- removed secured property from dt binding, defer it till we add
	support to secure buffers.
- reword various bits in bindings suggested by Rob Herring

Srinivas Kandagatla (5):
  misc: dt-bindings: Add Qualcomm Fastrpc bindings
  misc: fastrpc: Add Qualcomm fastrpc basic driver model
  misc: fastrpc: Add support for context Invoke method
  misc: fastrpc: Add support for create remote init process
  misc: fastrpc: Add support for dmabuf exporter

 .../devicetree/bindings/misc/qcom,fastrpc.txt |   78 +
 drivers/misc/Kconfig                          |   10 +
 drivers/misc/Makefile                         |    1 +
 drivers/misc/fastrpc.c                        | 1354 +++++++++++++++++
 include/uapi/misc/fastrpc.h                   |   41 +
 5 files changed, 1484 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/qcom,fastrpc.txt
 create mode 100644 drivers/misc/fastrpc.c
 create mode 100644 include/uapi/misc/fastrpc.h

-- 
2.20.1