driver: vservices: Add the vservices framework and core

Adds the Virtual Services framework and core protocol code.

The Virtual Services framework provides a bus for generic inter-vm
communications using a high level abstract model. The vservices
bus provides support for both HLOS and embedded C clients and servers,
allowing VMs to communicate in a common OS independent manner.

The vservices bus and services over it are hot-plug capable and
can support a wide variety of use cases, including device virtualization
using virtual device protocol (classes) and drivers, similar in
concept to USB or virtio.

Change-Id: I7a696354f59730e0ad340fb92dc85661a7376dee
Signed-off-by: Carl van Schaik <carl@cog.systems>
Git-commit: 42814676e8bf5fb34060ee80e05e2175ae146292
Git-repo: https://github.com/CogSystems/linux-msm/commits/msm-4.9-hyp
[mnalajal@codeaurora: Resolve trivial merge conflicts]
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>

drivers/Kconfig

@@ -137,6 +137,8 @@ source "drivers/hv/Kconfig"
 
 source "drivers/xen/Kconfig"
 
+source "drivers/vservices/Kconfig"
+
 source "drivers/staging/Kconfig"
 
 source "drivers/platform/Kconfig"

drivers/Makefile

@@ -11,6 +11,8 @@ obj-y				+= bus/
 
 obj-$(CONFIG_GENERIC_PHY)	+= phy/
 
+obj-$(CONFIG_VSERVICES_SUPPORT)	+= vservices/
+
 # GPIO must come after pinctrl as gpios may need to mux pins etc
 obj-$(CONFIG_PINCTRL)		+= pinctrl/
 obj-$(CONFIG_GPIOLIB)		+= gpio/

drivers/vservices/Kconfig

@@ -0,0 +1,81 @@
+#
+# OKL4 Virtual Services framework
+#
+
+menuconfig VSERVICES_SUPPORT
+	tristate "OKL4 Virtual Services support"
+	default OKL4_GUEST || OKL4_VIRTUALISATION
+	select HOTPLUG
+	help
+	  This option adds core support for OKL4 Virtual Services. The Virtual
+	  Services framework is an inter-OS device/service sharing
+	  protocol which is supported on OKL4 Microvisor virtualization
+	  platforms. You will also need drivers from the following menu in
+	  order to make use of it.
+
+if VSERVICES_SUPPORT
+
+config VSERVICES_CHAR_DEV
+	bool "Virtual Services user-space service API"
+	default y
+	help
+	  Select this if you want to use user-space service drivers. You will
+	  also need udev rules that create device nodes, and protocol code
+	  generated by the OK Mill tool.
+
+config VSERVICES_DEBUG
+	bool "Virtual Services debugging support"
+	help
+	  Select this if you want to enable Virtual Services core framework
+	  debugging. The debug messages for various components of the Virtual
+	  Services core framework can be toggled at runtime on a per-session
+	  basis via sysfs. When Virtual Services debugging is enabled here,
+	  but disabled at runtime it has a minimal performance impact.
+
+config VSERVICES_LOCK_DEBUG
+	bool "Debug Virtual Services state locks"
+	default DEBUG_KERNEL
+	help
+	  This option enables some runtime checks that Virtual Services
+	  state lock functions are used correctly in service drivers.
+
+config VSERVICES_SERVER
+	tristate "Virtual Services server support"
+	depends on SYSFS
+	default y
+	help
+	  This option adds support for Virtual Services servers, which allows
+	  exporting of services from this Linux to other environments. Servers
+	  are created at runtime by writing to files in
+	  /sys/bus/vservices-server.
+
+config VSERVICES_CLIENT
+	tristate "Virtual Services client support"
+	default y
+	help
+	  This option adds support for Virtual Services clients, which allows
+	  connecting to services exported from other environments.
+
+config VSERVICES_SKELETON_DRIVER
+	tristate "Virtual Services skeleton driver"
+	depends on VSERVICES_SERVER || VSERVICES_CLIENT
+	default n
+	help
+	  This option adds support for a skeleton virtual service driver. This
+	  driver can be used for templating or testing of virtual service
+	  drivers. If unsure say N.
+
+config VSERVICES_NAMED_DEVICE
+	bool "Virtual Services use named device node in /dev"
+	default n
+	help
+	  Select this if you want to use a named device name over a numeric
+	  device name in /dev
+
+source "drivers/vservices/transport/Kconfig"
+
+source "drivers/vservices/protocol/Kconfig"
+
+source "drivers/vservices/Kconfig.stacks"
+
+endif # VSERVICES_SUPPORT

drivers/vservices/Kconfig.stacks

@@ -0,0 +1,7 @@
+#
+# vServices drivers configuration
+#
+
+menu "Client and Server drivers"
+
+endmenu

drivers/vservices/Makefile

@@ -0,0 +1,14 @@
+ccflags-y += -Werror
+ccflags-$(CONFIG_VSERVICES_DEBUG) += -DDEBUG
+
+obj-$(CONFIG_VSERVICES_SUPPORT)	+= vservices.o
+vservices-objs-$(CONFIG_VSERVICES_CHAR_DEV) += devio.o
+vservices-objs = session.o $(vservices-objs-y)
+
+obj-$(CONFIG_VSERVICES_CLIENT) += core_client.o
+obj-$(CONFIG_VSERVICES_SERVER) += core_server.o
+
+obj-$(CONFIG_VSERVICES_SKELETON_DRIVER) += vservices_skeleton_driver.o
+vservices_skeleton_driver-objs = skeleton_driver.o
+
+obj-$(CONFIG_VSERVICES_SUPPORT) += protocol/

drivers/vservices/compat.h

@@ -0,0 +1,59 @@
+/*
+ * drivers/vservices/compat.h
+ *
+ * Copyright (c) 2012-2018 General Dynamics
+ * Copyright (c) 2014 Open Kernel Labs, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Wrapper functions/definitions for compatibility between differnet kernel
+ * versions.
+ */
+
+#ifndef _VSERVICES_COMPAT_H
+#define _VSERVICES_COMPAT_H
+
+#include <linux/workqueue.h>
+#include <linux/version.h>
+
+/* The INIT_WORK_ONSTACK macro has a slightly different name in older kernels */
+#ifndef INIT_WORK_ONSTACK
+#define INIT_WORK_ONSTACK(_work, _func) INIT_WORK_ON_STACK(_work, _func)
+#endif
+
+/*
+ * We require a workqueue with  no concurrency. This is provided by
+ * create_singlethread_workqueue() in kernel prior to 2.6.36.
+ * In later versions, create_singlethread_workqueue() enables WQ_MEM_RECLAIM and
+ * thus WQ_RESCUER, which allows work items to be grabbed by a rescuer thread
+ * and run concurrently if the queue is running too slowly. We must use
+ * alloc_ordered_workqueue() instead, to disable the rescuer.
+ */
+static inline struct workqueue_struct *
+vs_create_workqueue(const char *name)
+{
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
+	return create_singlethread_workqueue(name);
+#else
+	return alloc_ordered_workqueue(name, 0);
+#endif
+}
+
+/*
+ * The max3 macro has only been present from 2.6.37
+ * (commit: f27c85c56b32c42bcc54a43189c1e00fdceb23ec)
+ */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 37)
+#define max3(x, y, z) ({			\
+	typeof(x) _max1 = (x);			\
+	typeof(y) _max2 = (y);			\
+	typeof(z) _max3 = (z);			\
+	(void) (&_max1 == &_max2);		\
+	(void) (&_max1 == &_max3);		\
+	_max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
+		(_max2 > _max3 ? _max2 : _max3); })
+#endif
+
+#endif /* _VSERVICES_COMPAT_H */