android/ion: userspace test utility for ion buffer sharing

# SPDX-License-Identifier: GPL-2.0

TARGETS =  bpf

TARGETS = android

TARGETS += bpf

TARGETS += breakpoints

TARGETS += capabilities

TARGETS += cpufreq

SUBDIRS := ion

TEST_PROGS := run.sh

.PHONY: all clean

include ../lib.mk

all:

	@for DIR in $(SUBDIRS); do		\

		BUILD_TARGET=$(OUTPUT)/$$DIR;	\

		mkdir $$BUILD_TARGET  -p;	\

		make OUTPUT=$$BUILD_TARGET -C $$DIR $@;\

		#SUBDIR test prog name should be in the form: SUBDIR_test.sh

		TEST=$$DIR"_test.sh"; \

		if [ -e $$DIR/$$TEST ]; then

			rsync -a $$DIR/$$TEST $$BUILD_TARGET/;

		fi

	done

override define RUN_TESTS

	@cd $(OUTPUT); ./run.sh

endef

override define INSTALL_RULE

	mkdir -p $(INSTALL_PATH)

	install -t $(INSTALL_PATH) $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES)

	@for SUBDIR in $(SUBDIRS); do \

		BUILD_TARGET=$(OUTPUT)/$$SUBDIR;	\

		mkdir $$BUILD_TARGET  -p;	\

		$(MAKE) OUTPUT=$$BUILD_TARGET -C $$SUBDIR INSTALL_PATH=$(INSTALL_PATH)/$$SUBDIR install; \

	done;

endef

override define EMIT_TESTS

	echo "./run.sh"

endef

override define CLEAN

	@for DIR in $(SUBDIRS); do		\

		BUILD_TARGET=$(OUTPUT)/$$DIR;	\

		mkdir $$BUILD_TARGET  -p;	\

		make OUTPUT=$$BUILD_TARGET -C $$DIR $@;\

	done

endef

ionapp_export

ionapp_import

INCLUDEDIR := -I. -I../../../../../drivers/staging/android/uapi/

CFLAGS := $(CFLAGS) $(INCLUDEDIR) -Wall -O2 -g

TEST_GEN_FILES := ionapp_export ionapp_import

all: $(TEST_GEN_FILES)

$(TEST_GEN_FILES): ipcsocket.c ionutils.c

TEST_PROGS := ion_test.sh

include ../../lib.mk

$(OUTPUT)/ionapp_export: ionapp_export.c ipcsocket.c ionutils.c

$(OUTPUT)/ionapp_import: ionapp_import.c ipcsocket.c ionutils.c

ION BUFFER SHARING UTILITY

==========================

File: ion_test.sh : Utility to test ION driver buffer sharing mechanism.

Author: Pintu Kumar <pintu.ping@gmail.com>

Introduction:

-------------

This is a test utility to verify ION buffer sharing in user space

between 2 independent processes.

It uses unix domain socket (with SCM_RIGHTS) as IPC to transfer an FD to

another process to share the same buffer.

This utility demonstrates how ION buffer sharing can be implemented between

two user space processes, using various heap types.

The following heap types are supported by ION driver.

ION_HEAP_TYPE_SYSTEM (0)

ION_HEAP_TYPE_SYSTEM_CONTIG (1)

ION_HEAP_TYPE_CARVEOUT (2)

ION_HEAP_TYPE_CHUNK (3)

ION_HEAP_TYPE_DMA (4)

By default only the SYSTEM and SYSTEM_CONTIG heaps are supported.

Each heap is associated with the respective heap id.

This utility is designed in the form of client/server program.

The server part (ionapp_export) is the exporter of the buffer.

It is responsible for creating an ION client, allocating the buffer based on

the heap id, writing some data to this buffer and then exporting the FD

(associated with this buffer) to another process using socket IPC.

This FD is called as buffer FD (which is different than the ION client FD).

The client part (ionapp_import) is the importer of the buffer.

It retrives the FD from the socket data and installs into its address space.

This new FD internally points to the same kernel buffer.

So first it reads the data that is stored in this buffer and prints it.

Then it writes the different size of data (it could be different data) to the

same buffer.

Finally the buffer FD must be closed by both the exporter and importer.

Thus the same kernel buffer is shared among two user space processes using

ION driver and only one time allocation.

Prerequisite:

-------------

This utility works only if /dev/ion interface is present.

The following configs needs to be enabled in kernel to include ion driver.

CONFIG_ANDROID=y

CONFIG_STAGING=y

CONFIG_ION=y

CONFIG_ION_SYSTEM_HEAP=y

This utility requires to be run as root user.

Compile and test:

-----------------

This utility is made to be run as part of kselftest framework in kernel.

To compile and run using kselftest you can simply do the following from the

kernel top directory.

linux$ make TARGETS=android kselftest

Or you can also use:

linux$ make -C tools/testing/selftests TARGETS=android run_tests

Using the selftest it can directly execute the ion_test.sh script to test the

buffer sharing using ion system heap.

Currently the heap size is hard coded as just 10 bytes inside this script.

You need to be a root user to run under selftest.

You can also compile and test manually using the following steps:

ion$ make

These will generate 2 executable: ionapp_export, ionapp_import

Now you can run the export and import manually by specifying the heap type

and the heap size.

You can also directly execute the shell script to run the test automatically.

Simply use the following command to run the test.

ion$ sudo ./ion_test.sh

Test Results:

-------------

The utility is verified on Ubuntu-32 bit system with Linux Kernel 4.14.

Here is the snapshot of the test result using kselftest.

linux# make TARGETS=android kselftest

heap_type: 0, heap_size: 10

--------------------------------------

heap type: 0

  heap id: 1

heap name: ion_system_heap

--------------------------------------

Fill buffer content:

0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd

Sharing fd: 6, Client fd: 5

<ion_close_buffer_fd>: buffer release successfully....

Received buffer fd: 4

Read buffer content:

0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0x0 0x0 0x0 0x0 0x0 0x0

0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0 0x0

Fill buffer content:

0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd

0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd 0xfd

0xfd 0xfd

<ion_close_buffer_fd>: buffer release successfully....

ion_test.sh: heap_type: 0 - [PASS]

ion_test.sh: done