[PATCH 0/2] ION dummy driver

[PATCH 0/2] ION dummy driver

[John Stultz]

The ION subsystem requires something register it along with the
various heaps that may be available on a system in order to work
(Otherwise no /dev/ion is created).

This can make it difficult to play with. Thus I've created this
simple dummy driver which allocates and registers some basic heaps.

I've been using this dummy driver, along with Colin's unit tests
and test driver, to be able to validate basic functionality on
a number of architectures and it was handy to chase down a few
issues before ION was submitted to staging.

If you want to play with all of this, Colin's unit tests can be
found in AOSP under the system/core/libion directory, but if you
want to try to use them in a non-Android environment, I've
mirrored that directory and added some changes to get it building
under Ubuntu here:
   https://github.com/johnstultz-work/ion-test


Greg: I realize this is after the usual -rc6 cutoff for staging,
so no pressure if you want to defer this for 3.15, but I saw you've
picked up a few things recently, so I figured I'd send it out so
I'm not just sitting on it while we wait for LCA to finish.

thanks
-john

Cc: Colin Cross <ccross@android.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jesse Barker <jesse.barker@arm.com>
Cc: Android Kernel Team <kernel-team@android.com>

John Stultz (2):
  ion: Add dummy driver for testing
  ion: Add carveout and chunk heaps to dummy driver

 drivers/staging/android/ion/Kconfig            |  10 ++
 drivers/staging/android/ion/Makefile           |   3 +
 drivers/staging/android/ion/ion_dummy_driver.c | 158 +++++++++++++++++++++++++
 3 files changed, 171 insertions(+)
 create mode 100644 drivers/staging/android/ion/ion_dummy_driver.c

-- 
1.8.3.2

[PATCH 1/2] ion: Add dummy driver for testing

[John Stultz]

Provide a basic dummy driver to register the ion device
and to install basic SYSTEM and SYSTEM_CONTIG heaps.

This allows for basic testing with ION without having
access to drivers or systems that have been enabled to use
ION.

Cc: Colin Cross <ccross@android.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jesse Barker <jesse.barker@arm.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/staging/android/ion/Kconfig            | 10 +++
 drivers/staging/android/ion/Makefile           |  3 +
 drivers/staging/android/ion/ion_dummy_driver.c | 93 ++++++++++++++++++++++++++
 3 files changed, 106 insertions(+)
 create mode 100644 drivers/staging/android/ion/ion_dummy_driver.c

diff --git a/drivers/staging/android/ion/Kconfig b/drivers/staging/android/ion/Kconfig
index a9a64ea..a087b19 100644
--- a/drivers/staging/android/ion/Kconfig
+++ b/drivers/staging/android/ion/Kconfig
@@ -17,6 +17,16 @@ config ION_TEST
 	  Choose this option to create a device that can be used to test the
 	  kernel and device side ION functions.
 
+config ION_DUMMY
+	tristate "Dummy Ion driver"
+	depends on ION
+	help
+	  Provides a dummy ION driver that registers the
+	  /dev/ion device and some basic heaps. This can
+	  be used for testing the ION infrastructure if
+	  one doesn't have access to hardware drivers that
+	  use ION.
+
 config ION_TEGRA
 	tristate "Ion for Tegra"
 	depends on ARCH_TEGRA && ION
diff --git a/drivers/staging/android/ion/Makefile b/drivers/staging/android/ion/Makefile
index 75039b9..b56fd2b 100644
--- a/drivers/staging/android/ion/Makefile
+++ b/drivers/staging/android/ion/Makefile
@@ -4,4 +4,7 @@ obj-$(CONFIG_ION_TEST) += ion_test.o
 ifdef CONFIG_COMPAT
 obj-$(CONFIG_ION) += compat_ion.o
 endif
+
+obj-$(CONFIG_ION_DUMMY) += ion_dummy_driver.o
 obj-$(CONFIG_ION_TEGRA) += tegra/
+
diff --git a/drivers/staging/android/ion/ion_dummy_driver.c b/drivers/staging/android/ion/ion_dummy_driver.c
new file mode 100644
index 0000000..6749d29
--- /dev/null
+++ b/drivers/staging/android/ion/ion_dummy_driver.c
@@ -0,0 +1,93 @@
+/*
+ * drivers/gpu/ion/ion_dummy_driver.c
+ *
+ * Copyright (C) 2013 Linaro, Inc
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/sizes.h>
+#include "ion.h"
+#include "ion_priv.h"
+
+struct ion_device *idev;
+struct ion_heap **heaps;
+
+struct ion_platform_heap dummy_heaps[] = {
+		{
+			.id	= ION_HEAP_TYPE_SYSTEM,
+			.type	= ION_HEAP_TYPE_SYSTEM,
+			.name	= "system",
+		},
+		{
+			.id	= ION_HEAP_TYPE_SYSTEM_CONTIG,
+			.type	= ION_HEAP_TYPE_SYSTEM_CONTIG,
+			.name	= "system contig",
+		},
+};
+
+struct ion_platform_data dummy_ion_pdata = {
+	.nr = 2,
+	.heaps = dummy_heaps,
+};
+
+static int __init ion_dummy_init(void)
+{
+	int i, err;
+
+	idev = ion_device_create(NULL);
+	heaps = kzalloc(sizeof(struct ion_heap *) * dummy_ion_pdata.nr,
+			GFP_KERNEL);
+	if (!heaps)
+		return PTR_ERR(heaps);
+
+	for (i = 0; i < dummy_ion_pdata.nr; i++) {
+		struct ion_platform_heap *heap_data = &dummy_ion_pdata.heaps[i];
+
+		heaps[i] = ion_heap_create(heap_data);
+		if (IS_ERR_OR_NULL(heaps[i])) {
+			err = PTR_ERR(heaps[i]);
+			goto err;
+		}
+		ion_device_add_heap(idev, heaps[i]);
+	}
+	return 0;
+err:
+	for (i = 0; i < dummy_ion_pdata.nr; i++) {
+		if (heaps[i])
+			ion_heap_destroy(heaps[i]);
+	}
+	kfree(heaps);
+
+	return err;
+}
+
+static void __exit ion_dummy_exit(void)
+{
+	int i;
+
+	ion_device_destroy(idev);
+
+	for (i = 0; i < dummy_ion_pdata.nr; i++)
+		ion_heap_destroy(heaps[i]);
+	kfree(heaps);
+
+	return;
+}
+
+module_init(ion_dummy_init);
+module_exit(ion_dummy_exit);
+
-- 
1.8.3.2

[PATCH 2/2] ion: Add carveout and chunk heaps to dummy driver

[John Stultz]

Add support to the dummy driver for basic carveout and chunk heaps.

Since we're generating these heaps at module_init, and we want
this driver to be generic enough to be tested on any arch, we
don't have the ability to alloc bootmem, so both of these heaps
are conventionally allocated using alloc_pages(), which limits us
to 4M in size.

Should look into using CMA for heap allocation eventually, but
this provides enough to test the basic functionality of the
heaps.

Cc: Colin Cross <ccross@android.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jesse Barker <jesse.barker@arm.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/staging/android/ion/ion_dummy_driver.c | 67 +++++++++++++++++++++++++-
 1 file changed, 66 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/android/ion/ion_dummy_driver.c b/drivers/staging/android/ion/ion_dummy_driver.c
index 6749d29..55b2002 100644
--- a/drivers/staging/android/ion/ion_dummy_driver.c
+++ b/drivers/staging/android/ion/ion_dummy_driver.c
@@ -26,6 +26,9 @@
 struct ion_device *idev;
 struct ion_heap **heaps;
 
+void *carveout_ptr;
+void *chunk_ptr;
+
 struct ion_platform_heap dummy_heaps[] = {
 		{
 			.id	= ION_HEAP_TYPE_SYSTEM,
@@ -37,10 +40,24 @@ struct ion_platform_heap dummy_heaps[] = {
 			.type	= ION_HEAP_TYPE_SYSTEM_CONTIG,
 			.name	= "system contig",
 		},
+		{
+			.id	= ION_HEAP_TYPE_CARVEOUT,
+			.type	= ION_HEAP_TYPE_CARVEOUT,
+			.name	= "carveout",
+			.size	= SZ_4M,
+		},
+		{
+			.id	= ION_HEAP_TYPE_CHUNK,
+			.type	= ION_HEAP_TYPE_CHUNK,
+			.name	= "chunk",
+			.size	= SZ_4M,
+			.align	= SZ_16K,
+			.priv	= (void *)(SZ_16K),
+		},
 };
 
 struct ion_platform_data dummy_ion_pdata = {
-	.nr = 2,
+	.nr = 4,
 	.heaps = dummy_heaps,
 };
 
@@ -54,9 +71,36 @@ static int __init ion_dummy_init(void)
 	if (!heaps)
 		return PTR_ERR(heaps);
 
+
+	/* Allocate a dummy carveout heap */
+	carveout_ptr = alloc_pages_exact(
+				dummy_heaps[ION_HEAP_TYPE_CARVEOUT].size,
+				GFP_KERNEL);
+	if (carveout_ptr)
+		dummy_heaps[ION_HEAP_TYPE_CARVEOUT].base =
+						virt_to_phys(carveout_ptr);
+	else
+		pr_err("ion_dummy: Could not allocate carveout\n");
+
+	/* Allocate a dummy chunk heap */
+	chunk_ptr = alloc_pages_exact(
+				dummy_heaps[ION_HEAP_TYPE_CHUNK].size,
+				GFP_KERNEL);
+	if (chunk_ptr)
+		dummy_heaps[ION_HEAP_TYPE_CHUNK].base = virt_to_phys(chunk_ptr);
+	else
+		pr_err("ion_dummy: Could not allocate chunk\n");
+
 	for (i = 0; i < dummy_ion_pdata.nr; i++) {
 		struct ion_platform_heap *heap_data = &dummy_ion_pdata.heaps[i];
 
+		if (heap_data->type == ION_HEAP_TYPE_CARVEOUT &&
+							!heap_data->base)
+			continue;
+
+		if (heap_data->type == ION_HEAP_TYPE_CHUNK && !heap_data->base)
+			continue;
+
 		heaps[i] = ion_heap_create(heap_data);
 		if (IS_ERR_OR_NULL(heaps[i])) {
 			err = PTR_ERR(heaps[i]);
@@ -72,6 +116,16 @@ err:
 	}
 	kfree(heaps);
 
+	if (carveout_ptr) {
+		free_pages_exact(carveout_ptr,
+				dummy_heaps[ION_HEAP_TYPE_CARVEOUT].size);
+		carveout_ptr = NULL;
+	}
+	if (chunk_ptr) {
+		free_pages_exact(chunk_ptr,
+				dummy_heaps[ION_HEAP_TYPE_CHUNK].size);
+		chunk_ptr = NULL;
+	}
 	return err;
 }
 
@@ -85,6 +139,17 @@ static void __exit ion_dummy_exit(void)
 		ion_heap_destroy(heaps[i]);
 	kfree(heaps);
 
+	if (carveout_ptr) {
+		free_pages_exact(carveout_ptr,
+				dummy_heaps[ION_HEAP_TYPE_CARVEOUT].size);
+		carveout_ptr = NULL;
+	}
+	if (chunk_ptr) {
+		free_pages_exact(chunk_ptr,
+				dummy_heaps[ION_HEAP_TYPE_CHUNK].size);
+		chunk_ptr = NULL;
+	}
+
 	return;
 }
 
-- 
1.8.3.2

Re: [PATCH 0/2] ION dummy driver

[Greg KH]

On Thu, Jan 09, 2014 at 07:40:53PM -0800, John Stultz wrote:
> Greg: I realize this is after the usual -rc6 cutoff for staging,
> so no pressure if you want to defer this for 3.15, but I saw you've
> picked up a few things recently, so I figured I'd send it out so
> I'm not just sitting on it while we wait for LCA to finish.

I would have merged it, but I just tried and got a ton of errors when
building:

ERROR: "ion_device_destroy" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!
ERROR: "ion_heap_destroy" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!
ERROR: "ion_device_add_heap" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!
ERROR: "ion_heap_create" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!
ERROR: "ion_device_create" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!

So, I'll just drop these patches and forget you ever sent them to me :)

greg k-h

p.s.  Feel free to resend them when they work.

Re: [PATCH 0/2] ION dummy driver

[John Stultz]

On 01/09/2014 08:23 PM, Greg KH wrote:
> On Thu, Jan 09, 2014 at 07:40:53PM -0800, John Stultz wrote:
>> Greg: I realize this is after the usual -rc6 cutoff for staging,
>> so no pressure if you want to defer this for 3.15, but I saw you've
>> picked up a few things recently, so I figured I'd send it out so
>> I'm not just sitting on it while we wait for LCA to finish.
> I would have merged it, but I just tried and got a ton of errors when
> building:
>
> ERROR: "ion_device_destroy" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!
> ERROR: "ion_heap_destroy" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!
> ERROR: "ion_device_add_heap" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!
> ERROR: "ion_heap_create" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!
> ERROR: "ion_device_create" [drivers/staging/android/ion/ion_dummy_driver.ko] undefined!
>
> So, I'll just drop these patches and forget you ever sent them to me :)

Gah. Modules bite me every time! Should have been a bool and not
tristate in the Kconfig.

Sorry! I appreciate the heads up and the build related amnesia.  :)

thanks
-john