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[1/4] ion: Introduce the ION subsystem

Message ID 1369441185-3434-2-git-send-email-john.stultz@linaro.org
State Superseded
Headers show

Commit Message

John Stultz May 25, 2013, 12:19 a.m. UTC
ION is a memory manager for use graphics, multimedia and other
uses that facilitates buffer sharing between devices, including
devices that have particular constraints on the types of memory
they can access.

ION manages the allocation of buffers from a series of heaps, and
can export those buffers as dma_bufs.

This patch introduces the core ION subsystem and the SYSTEM (vmalloc)
and SYSTEM_CONTIG (kzmalloc) heaps.

This work was originally by Rebecca Schultz Zavin <rebecca@android.com>

And contains fixes and improvements by:
	Arve Hjønnevåg <arve@android.com>
	Benjamin Gaignard <benjamin.gaignard@linaro.org>
	Colin Cross <ccross@android.com>
	Dima Zavin <dima@android.com>
	Greg Hackmann <ghackmann@google.com>
	Jesse Barker <jesse.barker@arm.com>
	Johan Mossberg <johan.mossberg@stericsson.com>
	JP Abgrall <jpa@google.com>
	KyongHo Cho <pullip.cho@samsung.com>
	Laura Abbott <lauraa@codeaurora.org>
	Olav Haugan <ohaugan@codeaurora.org>

TODOS:
* Improve upstream rational/jusitifcation
* Sort out dma_sync_single_for_device usage (null device ptr) issue
* pfn_to_dma (and friends) usage and macros
* kill ION_IOC_CUSTOM ioctl multiplexer

Cc: Jesse Barker <jesse.barker@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Serban Constantinescu <Serban.Constantinescu@arm.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/gpu/Makefile              |    3 +-
 drivers/gpu/ion/Kconfig           |   13 +
 drivers/gpu/ion/Makefile          |    1 +
 drivers/gpu/ion/ion.c             | 1462 +++++++++++++++++++++++++++++++++++++
 drivers/gpu/ion/ion_heap.c        |  178 +++++
 drivers/gpu/ion/ion_page_pool.c   |  282 +++++++
 drivers/gpu/ion/ion_priv.h        |  302 ++++++++
 drivers/gpu/ion/ion_system_heap.c |  418 +++++++++++
 drivers/video/Kconfig             |    2 +
 include/linux/ion.h               |  365 +++++++++
 10 files changed, 3025 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/ion/Kconfig
 create mode 100644 drivers/gpu/ion/Makefile
 create mode 100644 drivers/gpu/ion/ion.c
 create mode 100644 drivers/gpu/ion/ion_heap.c
 create mode 100644 drivers/gpu/ion/ion_page_pool.c
 create mode 100644 drivers/gpu/ion/ion_priv.h
 create mode 100644 drivers/gpu/ion/ion_system_heap.c
 create mode 100644 include/linux/ion.h
diff mbox

Patch

diff --git a/drivers/gpu/Makefile b/drivers/gpu/Makefile
index d8a22c2..fcc0c8b 100644
--- a/drivers/gpu/Makefile
+++ b/drivers/gpu/Makefile
@@ -1,2 +1,3 @@ 
-obj-y			+= drm/ vga/
+obj-y			+= drm/ vga/ ion/
 obj-$(CONFIG_TEGRA_HOST1X)	+= host1x/
+
diff --git a/drivers/gpu/ion/Kconfig b/drivers/gpu/ion/Kconfig
new file mode 100644
index 0000000..b5bfdb4
--- /dev/null
+++ b/drivers/gpu/ion/Kconfig
@@ -0,0 +1,13 @@ 
+menuconfig ION
+	tristate "Ion Memory Manager"
+	select GENERIC_ALLOCATOR
+	select DMA_SHARED_BUFFER
+	help
+	  Chose this option to enable the ION Memory Manager.
+
+config ION_TEGRA
+	tristate "Ion for Tegra"
+	depends on ARCH_TEGRA && ION
+	help
+	  Choose this option if you wish to use ion on an nVidia Tegra.
+
diff --git a/drivers/gpu/ion/Makefile b/drivers/gpu/ion/Makefile
new file mode 100644
index 0000000..cc144dc
--- /dev/null
+++ b/drivers/gpu/ion/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_ION) +=	ion.o ion_heap.o ion_page_pool.o ion_system_heap.o 
diff --git a/drivers/gpu/ion/ion.c b/drivers/gpu/ion/ion.c
new file mode 100644
index 0000000..a8ae679
--- /dev/null
+++ b/drivers/gpu/ion/ion.c
@@ -0,0 +1,1462 @@ 
+/*
+
+ * drivers/gpu/ion/ion.c
+ *
+ * Copyright (C) 2011 Google, 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/device.h>
+#include <linux/file.h>
+#include <linux/freezer.h>
+#include <linux/fs.h>
+#include <linux/anon_inodes.h>
+#include <linux/ion.h>
+#include <linux/kthread.h>
+#include <linux/list.h>
+#include <linux/memblock.h>
+#include <linux/miscdevice.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/mm_types.h>
+#include <linux/rbtree.h>
+#include <linux/rtmutex.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/debugfs.h>
+#include <linux/dma-buf.h>
+
+#include "ion_priv.h"
+
+/**
+ * struct ion_device - the metadata of the ion device node
+ * @dev:		the actual misc device
+ * @buffers:		an rb tree of all the existing buffers
+ * @buffer_lock:	lock protecting the tree of buffers
+ * @lock:		rwsem protecting the tree of heaps and clients
+ * @heaps:		list of all the heaps in the system
+ * @user_clients:	list of all the clients created from userspace
+ */
+struct ion_device {
+	struct miscdevice dev;
+	struct rb_root buffers;
+	struct mutex buffer_lock;
+	struct rw_semaphore lock;
+	struct plist_head heaps;
+	long (*custom_ioctl) (struct ion_client *client, unsigned int cmd,
+			      unsigned long arg);
+	struct rb_root clients;
+	struct dentry *debug_root;
+};
+
+/**
+ * struct ion_client - a process/hw block local address space
+ * @node:		node in the tree of all clients
+ * @dev:		backpointer to ion device
+ * @handles:		an rb tree of all the handles in this client
+ * @lock:		lock protecting the tree of handles
+ * @name:		used for debugging
+ * @task:		used for debugging
+ *
+ * A client represents a list of buffers this client may access.
+ * The mutex stored here is used to protect both handles tree
+ * as well as the handles themselves, and should be held while modifying either.
+ */
+struct ion_client {
+	struct rb_node node;
+	struct ion_device *dev;
+	struct rb_root handles;
+	struct mutex lock;
+	const char *name;
+	struct task_struct *task;
+	pid_t pid;
+	struct dentry *debug_root;
+};
+
+/**
+ * ion_handle - a client local reference to a buffer
+ * @ref:		reference count
+ * @client:		back pointer to the client the buffer resides in
+ * @buffer:		pointer to the buffer
+ * @node:		node in the client's handle rbtree
+ * @kmap_cnt:		count of times this client has mapped to kernel
+ * @dmap_cnt:		count of times this client has mapped for dma
+ *
+ * Modifications to node, map_cnt or mapping should be protected by the
+ * lock in the client.  Other fields are never changed after initialization.
+ */
+struct ion_handle {
+	struct kref ref;
+	struct ion_client *client;
+	struct ion_buffer *buffer;
+	struct rb_node node;
+	unsigned int kmap_cnt;
+};
+
+bool ion_buffer_fault_user_mappings(struct ion_buffer *buffer)
+{
+        return ((buffer->flags & ION_FLAG_CACHED) &&
+                !(buffer->flags & ION_FLAG_CACHED_NEEDS_SYNC));
+}
+
+bool ion_buffer_cached(struct ion_buffer *buffer)
+{
+        return !!(buffer->flags & ION_FLAG_CACHED);
+}
+
+/* this function should only be called while dev->lock is held */
+static void ion_buffer_add(struct ion_device *dev,
+			   struct ion_buffer *buffer)
+{
+	struct rb_node **p = &dev->buffers.rb_node;
+	struct rb_node *parent = NULL;
+	struct ion_buffer *entry;
+
+	while (*p) {
+		parent = *p;
+		entry = rb_entry(parent, struct ion_buffer, node);
+
+		if (buffer < entry) {
+			p = &(*p)->rb_left;
+		} else if (buffer > entry) {
+			p = &(*p)->rb_right;
+		} else {
+			pr_err("%s: buffer already found.", __func__);
+			BUG();
+		}
+	}
+
+	rb_link_node(&buffer->node, parent, p);
+	rb_insert_color(&buffer->node, &dev->buffers);
+}
+
+static int ion_buffer_alloc_dirty(struct ion_buffer *buffer);
+
+static bool ion_heap_drain_freelist(struct ion_heap *heap);
+/* this function should only be called while dev->lock is held */
+static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,
+				     struct ion_device *dev,
+				     unsigned long len,
+				     unsigned long align,
+				     unsigned long flags)
+{
+	struct ion_buffer *buffer;
+	struct sg_table *table;
+	struct scatterlist *sg;
+	int i, ret;
+
+	buffer = kzalloc(sizeof(struct ion_buffer), GFP_KERNEL);
+	if (!buffer)
+		return ERR_PTR(-ENOMEM);
+
+	buffer->heap = heap;
+	buffer->flags = flags;
+	kref_init(&buffer->ref);
+
+	ret = heap->ops->allocate(heap, buffer, len, align, flags);
+
+	if (ret) {
+		if (!(heap->flags & ION_HEAP_FLAG_DEFER_FREE))
+			goto err2;
+
+		ion_heap_drain_freelist(heap);
+		ret = heap->ops->allocate(heap, buffer, len, align,
+					  flags);
+		if (ret)
+			goto err2;
+	}
+
+	buffer->dev = dev;
+	buffer->size = len;
+
+	table = heap->ops->map_dma(heap, buffer);
+	if (IS_ERR_OR_NULL(table)) {
+		heap->ops->free(buffer);
+		kfree(buffer);
+		return ERR_PTR(PTR_ERR(table));
+	}
+	buffer->sg_table = table;
+	if (ion_buffer_fault_user_mappings(buffer)) {
+		for_each_sg(buffer->sg_table->sgl, sg, buffer->sg_table->nents,
+			    i) {
+			if (sg_dma_len(sg) == PAGE_SIZE)
+				continue;
+			pr_err("%s: cached mappings that will be faulted in "
+			       "must have pagewise sg_lists\n", __func__);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		ret = ion_buffer_alloc_dirty(buffer);
+		if (ret)
+			goto err;
+	}
+
+	buffer->dev = dev;
+	buffer->size = len;
+	INIT_LIST_HEAD(&buffer->vmas);
+	mutex_init(&buffer->lock);
+	/* this will set up dma addresses for the sglist -- it is not
+	   technically correct as per the dma api -- a specific
+	   device isn't really taking ownership here.  However, in practice on
+	   our systems the only dma_address space is physical addresses.
+	   Additionally, we can't afford the overhead of invalidating every
+	   allocation via dma_map_sg. The implicit contract here is that
+	   memory comming from the heaps is ready for dma, ie if it has a
+	   cached mapping that mapping has been invalidated */
+	for_each_sg(buffer->sg_table->sgl, sg, buffer->sg_table->nents, i)
+		sg_dma_address(sg) = sg_phys(sg);
+	mutex_lock(&dev->buffer_lock);
+	ion_buffer_add(dev, buffer);
+	mutex_unlock(&dev->buffer_lock);
+	return buffer;
+
+err:
+	heap->ops->unmap_dma(heap, buffer);
+	heap->ops->free(buffer);
+err2:
+	kfree(buffer);
+	return ERR_PTR(ret);
+}
+
+static void _ion_buffer_destroy(struct ion_buffer *buffer)
+{
+	if (WARN_ON(buffer->kmap_cnt > 0))
+		buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
+	buffer->heap->ops->unmap_dma(buffer->heap, buffer);
+	buffer->heap->ops->free(buffer);
+	if (buffer->flags & ION_FLAG_CACHED)
+		kfree(buffer->dirty);
+	kfree(buffer);
+}
+
+static void ion_buffer_destroy(struct kref *kref)
+{
+	struct ion_buffer *buffer = container_of(kref, struct ion_buffer, ref);
+	struct ion_heap *heap = buffer->heap;
+	struct ion_device *dev = buffer->dev;
+
+	mutex_lock(&dev->buffer_lock);
+	rb_erase(&buffer->node, &dev->buffers);
+	mutex_unlock(&dev->buffer_lock);
+
+	if (heap->flags & ION_HEAP_FLAG_DEFER_FREE) {
+		rt_mutex_lock(&heap->lock);
+		list_add(&buffer->list, &heap->free_list);
+		rt_mutex_unlock(&heap->lock);
+		wake_up(&heap->waitqueue);
+		return;
+	}
+	_ion_buffer_destroy(buffer);
+}
+
+static void ion_buffer_get(struct ion_buffer *buffer)
+{
+	kref_get(&buffer->ref);
+}
+
+static int ion_buffer_put(struct ion_buffer *buffer)
+{
+	return kref_put(&buffer->ref, ion_buffer_destroy);
+}
+
+static void ion_buffer_add_to_handle(struct ion_buffer *buffer)
+{
+	mutex_lock(&buffer->lock);
+	buffer->handle_count++;
+	mutex_unlock(&buffer->lock);
+}
+
+static void ion_buffer_remove_from_handle(struct ion_buffer *buffer)
+{
+	/*
+	 * when a buffer is removed from a handle, if it is not in
+	 * any other handles, copy the taskcomm and the pid of the
+	 * process it's being removed from into the buffer.  At this
+	 * point there will be no way to track what processes this buffer is
+	 * being used by, it only exists as a dma_buf file descriptor.
+	 * The taskcomm and pid can provide a debug hint as to where this fd
+	 * is in the system
+	 */
+	mutex_lock(&buffer->lock);
+	buffer->handle_count--;
+	BUG_ON(buffer->handle_count < 0);
+	if (!buffer->handle_count) {
+		struct task_struct *task;
+
+		task = current->group_leader;
+		get_task_comm(buffer->task_comm, task);
+		buffer->pid = task_pid_nr(task);
+	}
+	mutex_unlock(&buffer->lock);
+}
+
+static struct ion_handle *ion_handle_create(struct ion_client *client,
+				     struct ion_buffer *buffer)
+{
+	struct ion_handle *handle;
+
+	handle = kzalloc(sizeof(struct ion_handle), GFP_KERNEL);
+	if (!handle)
+		return ERR_PTR(-ENOMEM);
+	kref_init(&handle->ref);
+	RB_CLEAR_NODE(&handle->node);
+	handle->client = client;
+	ion_buffer_get(buffer);
+	ion_buffer_add_to_handle(buffer);
+	handle->buffer = buffer;
+
+	return handle;
+}
+
+static void ion_handle_kmap_put(struct ion_handle *);
+
+static void ion_handle_destroy(struct kref *kref)
+{
+	struct ion_handle *handle = container_of(kref, struct ion_handle, ref);
+	struct ion_client *client = handle->client;
+	struct ion_buffer *buffer = handle->buffer;
+
+	mutex_lock(&buffer->lock);
+	while (handle->kmap_cnt)
+		ion_handle_kmap_put(handle);
+	mutex_unlock(&buffer->lock);
+
+	if (!RB_EMPTY_NODE(&handle->node))
+		rb_erase(&handle->node, &client->handles);
+
+	ion_buffer_remove_from_handle(buffer);
+	ion_buffer_put(buffer);
+
+	kfree(handle);
+}
+
+struct ion_buffer *ion_handle_buffer(struct ion_handle *handle)
+{
+	return handle->buffer;
+}
+
+static void ion_handle_get(struct ion_handle *handle)
+{
+	kref_get(&handle->ref);
+}
+
+static int ion_handle_put(struct ion_handle *handle)
+{
+	return kref_put(&handle->ref, ion_handle_destroy);
+}
+
+static struct ion_handle *ion_handle_lookup(struct ion_client *client,
+					    struct ion_buffer *buffer)
+{
+	struct rb_node *n;
+
+	for (n = rb_first(&client->handles); n; n = rb_next(n)) {
+		struct ion_handle *handle = rb_entry(n, struct ion_handle,
+						     node);
+		if (handle->buffer == buffer)
+			return handle;
+	}
+	return NULL;
+}
+
+static bool ion_handle_validate(struct ion_client *client, struct ion_handle *handle)
+{
+	struct rb_node *n = client->handles.rb_node;
+
+	while (n) {
+		struct ion_handle *handle_node = rb_entry(n, struct ion_handle,
+							  node);
+		if (handle < handle_node)
+			n = n->rb_left;
+		else if (handle > handle_node)
+			n = n->rb_right;
+		else
+			return true;
+	}
+	return false;
+}
+
+static void ion_handle_add(struct ion_client *client, struct ion_handle *handle)
+{
+	struct rb_node **p = &client->handles.rb_node;
+	struct rb_node *parent = NULL;
+	struct ion_handle *entry;
+
+	while (*p) {
+		parent = *p;
+		entry = rb_entry(parent, struct ion_handle, node);
+
+		if (handle < entry)
+			p = &(*p)->rb_left;
+		else if (handle > entry)
+			p = &(*p)->rb_right;
+		else
+			WARN(1, "%s: buffer already found.", __func__);
+	}
+
+	rb_link_node(&handle->node, parent, p);
+	rb_insert_color(&handle->node, &client->handles);
+}
+
+struct ion_handle *ion_alloc(struct ion_client *client, size_t len,
+			     size_t align, unsigned int heap_id_mask,
+			     unsigned int flags)
+{
+	struct ion_handle *handle;
+	struct ion_device *dev = client->dev;
+	struct ion_buffer *buffer = NULL;
+	struct ion_heap *heap;
+
+	pr_debug("%s: len %lu align %lu heap_id_mask %u flags %x\n", __func__,
+		 (unsigned long)len, (unsigned long)align, heap_id_mask, flags);
+	/*
+	 * traverse the list of heaps available in this system in priority
+	 * order.  If the heap type is supported by the client, and matches the
+	 * request of the caller allocate from it.  Repeat until allocate has
+	 * succeeded or all heaps have been tried
+	 */
+	if (WARN_ON(!len))
+		return ERR_PTR(-EINVAL);
+
+	len = PAGE_ALIGN(len);
+
+	down_read(&dev->lock);
+	plist_for_each_entry(heap, &dev->heaps, node) {
+		/* if the caller didn't specify this heap id */
+		if (!((1 << heap->id) & heap_id_mask))
+			continue;
+		buffer = ion_buffer_create(heap, dev, len, align, flags);
+		if (!IS_ERR_OR_NULL(buffer))
+			break;
+	}
+	up_read(&dev->lock);
+
+	if (buffer == NULL)
+		return ERR_PTR(-ENODEV);
+
+	if (IS_ERR(buffer))
+		return ERR_PTR(PTR_ERR(buffer));
+
+	handle = ion_handle_create(client, buffer);
+
+	/*
+	 * ion_buffer_create will create a buffer with a ref_cnt of 1,
+	 * and ion_handle_create will take a second reference, drop one here
+	 */
+	ion_buffer_put(buffer);
+
+	if (!IS_ERR(handle)) {
+		mutex_lock(&client->lock);
+		ion_handle_add(client, handle);
+		mutex_unlock(&client->lock);
+	}
+
+
+	return handle;
+}
+EXPORT_SYMBOL(ion_alloc);
+
+void ion_free(struct ion_client *client, struct ion_handle *handle)
+{
+	bool valid_handle;
+
+	BUG_ON(client != handle->client);
+
+	mutex_lock(&client->lock);
+	valid_handle = ion_handle_validate(client, handle);
+
+	if (!valid_handle) {
+		WARN(1, "%s: invalid handle passed to free.\n", __func__);
+		mutex_unlock(&client->lock);
+		return;
+	}
+	ion_handle_put(handle);
+	mutex_unlock(&client->lock);
+}
+EXPORT_SYMBOL(ion_free);
+
+int ion_phys(struct ion_client *client, struct ion_handle *handle,
+	     ion_phys_addr_t *addr, size_t *len)
+{
+	struct ion_buffer *buffer;
+	int ret;
+
+	mutex_lock(&client->lock);
+	if (!ion_handle_validate(client, handle)) {
+		mutex_unlock(&client->lock);
+		return -EINVAL;
+	}
+
+	buffer = handle->buffer;
+
+	if (!buffer->heap->ops->phys) {
+		pr_err("%s: ion_phys is not implemented by this heap.\n",
+		       __func__);
+		mutex_unlock(&client->lock);
+		return -ENODEV;
+	}
+	mutex_unlock(&client->lock);
+	ret = buffer->heap->ops->phys(buffer->heap, buffer, addr, len);
+	return ret;
+}
+EXPORT_SYMBOL(ion_phys);
+
+static void *ion_buffer_kmap_get(struct ion_buffer *buffer)
+{
+	void *vaddr;
+
+	if (buffer->kmap_cnt) {
+		buffer->kmap_cnt++;
+		return buffer->vaddr;
+	}
+	vaddr = buffer->heap->ops->map_kernel(buffer->heap, buffer);
+	if (IS_ERR_OR_NULL(vaddr))
+		return vaddr;
+	buffer->vaddr = vaddr;
+	buffer->kmap_cnt++;
+	return vaddr;
+}
+
+static void *ion_handle_kmap_get(struct ion_handle *handle)
+{
+	struct ion_buffer *buffer = handle->buffer;
+	void *vaddr;
+
+	if (handle->kmap_cnt) {
+		handle->kmap_cnt++;
+		return buffer->vaddr;
+	}
+	vaddr = ion_buffer_kmap_get(buffer);
+	if (IS_ERR_OR_NULL(vaddr))
+		return vaddr;
+	handle->kmap_cnt++;
+	return vaddr;
+}
+
+static void ion_buffer_kmap_put(struct ion_buffer *buffer)
+{
+	buffer->kmap_cnt--;
+	if (!buffer->kmap_cnt) {
+		buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
+		buffer->vaddr = NULL;
+	}
+}
+
+static void ion_handle_kmap_put(struct ion_handle *handle)
+{
+	struct ion_buffer *buffer = handle->buffer;
+
+	handle->kmap_cnt--;
+	if (!handle->kmap_cnt)
+		ion_buffer_kmap_put(buffer);
+}
+
+void *ion_map_kernel(struct ion_client *client, struct ion_handle *handle)
+{
+	struct ion_buffer *buffer;
+	void *vaddr;
+
+	mutex_lock(&client->lock);
+	if (!ion_handle_validate(client, handle)) {
+		pr_err("%s: invalid handle passed to map_kernel.\n",
+		       __func__);
+		mutex_unlock(&client->lock);
+		return ERR_PTR(-EINVAL);
+	}
+
+	buffer = handle->buffer;
+
+	if (!handle->buffer->heap->ops->map_kernel) {
+		pr_err("%s: map_kernel is not implemented by this heap.\n",
+		       __func__);
+		mutex_unlock(&client->lock);
+		return ERR_PTR(-ENODEV);
+	}
+
+	mutex_lock(&buffer->lock);
+	vaddr = ion_handle_kmap_get(handle);
+	mutex_unlock(&buffer->lock);
+	mutex_unlock(&client->lock);
+	return vaddr;
+}
+EXPORT_SYMBOL(ion_map_kernel);
+
+void ion_unmap_kernel(struct ion_client *client, struct ion_handle *handle)
+{
+	struct ion_buffer *buffer;
+
+	mutex_lock(&client->lock);
+	buffer = handle->buffer;
+	mutex_lock(&buffer->lock);
+	ion_handle_kmap_put(handle);
+	mutex_unlock(&buffer->lock);
+	mutex_unlock(&client->lock);
+}
+EXPORT_SYMBOL(ion_unmap_kernel);
+
+static int ion_debug_client_show(struct seq_file *s, void *unused)
+{
+	struct ion_client *client = s->private;
+	struct rb_node *n;
+	size_t sizes[ION_NUM_HEAP_IDS] = {0};
+	const char *names[ION_NUM_HEAP_IDS] = {0};
+	int i;
+
+	mutex_lock(&client->lock);
+	for (n = rb_first(&client->handles); n; n = rb_next(n)) {
+		struct ion_handle *handle = rb_entry(n, struct ion_handle,
+						     node);
+		unsigned int id = handle->buffer->heap->id;
+
+		if (!names[id])
+			names[id] = handle->buffer->heap->name;
+		sizes[id] += handle->buffer->size;
+	}
+	mutex_unlock(&client->lock);
+
+	seq_printf(s, "%16.16s: %16.16s\n", "heap_name", "size_in_bytes");
+	for (i = 0; i < ION_NUM_HEAP_IDS; i++) {
+		if (!names[i])
+			continue;
+		seq_printf(s, "%16.16s: %16lu\n", names[i], (unsigned long)sizes[i]);
+	}
+	return 0;
+}
+
+static int ion_debug_client_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ion_debug_client_show, inode->i_private);
+}
+
+static const struct file_operations debug_client_fops = {
+	.open = ion_debug_client_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+struct ion_client *ion_client_create(struct ion_device *dev,
+				     const char *name)
+{
+	struct ion_client *client;
+	struct task_struct *task;
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct ion_client *entry;
+	char debug_name[64];
+	pid_t pid;
+
+	get_task_struct(current->group_leader);
+	task_lock(current->group_leader);
+	pid = task_pid_nr(current->group_leader);
+	/* don't bother to store task struct for kernel threads,
+	   they can't be killed anyway */
+	if (current->group_leader->flags & PF_KTHREAD) {
+		put_task_struct(current->group_leader);
+		task = NULL;
+	} else {
+		task = current->group_leader;
+	}
+	task_unlock(current->group_leader);
+
+	client = kzalloc(sizeof(struct ion_client), GFP_KERNEL);
+	if (!client) {
+		if (task)
+			put_task_struct(current->group_leader);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	client->dev = dev;
+	client->handles = RB_ROOT;
+	mutex_init(&client->lock);
+	client->name = name;
+	client->task = task;
+	client->pid = pid;
+
+	down_write(&dev->lock);
+	p = &dev->clients.rb_node;
+	while (*p) {
+		parent = *p;
+		entry = rb_entry(parent, struct ion_client, node);
+
+		if (client < entry)
+			p = &(*p)->rb_left;
+		else if (client > entry)
+			p = &(*p)->rb_right;
+	}
+	rb_link_node(&client->node, parent, p);
+	rb_insert_color(&client->node, &dev->clients);
+
+	snprintf(debug_name, 64, "%u", client->pid);
+	client->debug_root = debugfs_create_file(debug_name, 0664,
+						 dev->debug_root, client,
+						 &debug_client_fops);
+	up_write(&dev->lock);
+
+	return client;
+}
+EXPORT_SYMBOL(ion_client_create);
+
+void ion_client_destroy(struct ion_client *client)
+{
+	struct ion_device *dev = client->dev;
+	struct rb_node *n;
+
+	pr_debug("%s: %d\n", __func__, __LINE__);
+	while ((n = rb_first(&client->handles))) {
+		struct ion_handle *handle = rb_entry(n, struct ion_handle,
+						     node);
+		ion_handle_destroy(&handle->ref);
+	}
+	down_write(&dev->lock);
+	if (client->task)
+		put_task_struct(client->task);
+	rb_erase(&client->node, &dev->clients);
+	debugfs_remove_recursive(client->debug_root);
+	up_write(&dev->lock);
+
+	kfree(client);
+}
+EXPORT_SYMBOL(ion_client_destroy);
+
+struct sg_table *ion_sg_table(struct ion_client *client,
+			      struct ion_handle *handle)
+{
+	struct ion_buffer *buffer;
+	struct sg_table *table;
+
+	mutex_lock(&client->lock);
+	if (!ion_handle_validate(client, handle)) {
+		pr_err("%s: invalid handle passed to map_dma.\n",
+		       __func__);
+		mutex_unlock(&client->lock);
+		return ERR_PTR(-EINVAL);
+	}
+	buffer = handle->buffer;
+	table = buffer->sg_table;
+	mutex_unlock(&client->lock);
+	return table;
+}
+EXPORT_SYMBOL(ion_sg_table);
+
+static void ion_buffer_sync_for_device(struct ion_buffer *buffer,
+				       struct device *dev,
+				       enum dma_data_direction direction);
+
+static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment,
+					enum dma_data_direction direction)
+{
+	struct dma_buf *dmabuf = attachment->dmabuf;
+	struct ion_buffer *buffer = dmabuf->priv;
+
+	ion_buffer_sync_for_device(buffer, attachment->dev, direction);
+	return buffer->sg_table;
+}
+
+static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment,
+			      struct sg_table *table,
+			      enum dma_data_direction direction)
+{
+}
+
+static int ion_buffer_alloc_dirty(struct ion_buffer *buffer)
+{
+	unsigned long pages = buffer->sg_table->nents;
+	unsigned long length = (pages + BITS_PER_LONG - 1)/BITS_PER_LONG;
+
+	buffer->dirty = kzalloc(length * sizeof(unsigned long), GFP_KERNEL);
+	if (!buffer->dirty)
+		return -ENOMEM;
+	return 0;
+}
+
+struct ion_vma_list {
+	struct list_head list;
+	struct vm_area_struct *vma;
+};
+
+static void ion_buffer_sync_for_device(struct ion_buffer *buffer,
+				       struct device *dev,
+				       enum dma_data_direction dir)
+{
+	struct scatterlist *sg;
+	int i;
+	struct ion_vma_list *vma_list;
+
+	pr_debug("%s: syncing for device %s\n", __func__,
+		 dev ? dev_name(dev) : "null");
+
+	if (!ion_buffer_fault_user_mappings(buffer))
+		return;
+
+	mutex_lock(&buffer->lock);
+	for_each_sg(buffer->sg_table->sgl, sg, buffer->sg_table->nents, i) {
+		if (!test_bit(i, buffer->dirty))
+			continue;
+		dma_sync_sg_for_device(dev, sg, 1, dir);
+		clear_bit(i, buffer->dirty);
+	}
+	list_for_each_entry(vma_list, &buffer->vmas, list) {
+		struct vm_area_struct *vma = vma_list->vma;
+
+		zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start,
+			       NULL);
+	}
+	mutex_unlock(&buffer->lock);
+}
+
+int ion_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct ion_buffer *buffer = vma->vm_private_data;
+	struct scatterlist *sg;
+	int i;
+
+	mutex_lock(&buffer->lock);
+	set_bit(vmf->pgoff, buffer->dirty);
+
+	for_each_sg(buffer->sg_table->sgl, sg, buffer->sg_table->nents, i) {
+		if (i != vmf->pgoff)
+			continue;
+		dma_sync_sg_for_cpu(NULL, sg, 1, DMA_BIDIRECTIONAL);
+		vm_insert_page(vma, (unsigned long)vmf->virtual_address,
+			       sg_page(sg));
+		break;
+	}
+	mutex_unlock(&buffer->lock);
+	return VM_FAULT_NOPAGE;
+}
+
+static void ion_vm_open(struct vm_area_struct *vma)
+{
+	struct ion_buffer *buffer = vma->vm_private_data;
+	struct ion_vma_list *vma_list;
+
+	vma_list = kmalloc(sizeof(struct ion_vma_list), GFP_KERNEL);
+	if (!vma_list)
+		return;
+	vma_list->vma = vma;
+	mutex_lock(&buffer->lock);
+	list_add(&vma_list->list, &buffer->vmas);
+	mutex_unlock(&buffer->lock);
+	pr_debug("%s: adding %p\n", __func__, vma);
+}
+
+static void ion_vm_close(struct vm_area_struct *vma)
+{
+	struct ion_buffer *buffer = vma->vm_private_data;
+	struct ion_vma_list *vma_list, *tmp;
+
+	pr_debug("%s\n", __func__);
+	mutex_lock(&buffer->lock);
+	list_for_each_entry_safe(vma_list, tmp, &buffer->vmas, list) {
+		if (vma_list->vma != vma)
+			continue;
+		list_del(&vma_list->list);
+		kfree(vma_list);
+		pr_debug("%s: deleting %p\n", __func__, vma);
+		break;
+	}
+	mutex_unlock(&buffer->lock);
+}
+
+struct vm_operations_struct ion_vma_ops = {
+	.open = ion_vm_open,
+	.close = ion_vm_close,
+	.fault = ion_vm_fault,
+};
+
+static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+	int ret = 0;
+
+	if (!buffer->heap->ops->map_user) {
+		pr_err("%s: this heap does not define a method for mapping "
+		       "to userspace\n", __func__);
+		return -EINVAL;
+	}
+
+	if (ion_buffer_fault_user_mappings(buffer)) {
+		vma->vm_private_data = buffer;
+		vma->vm_ops = &ion_vma_ops;
+		ion_vm_open(vma);
+		return 0;
+	}
+
+	if (!(buffer->flags & ION_FLAG_CACHED))
+		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+
+	mutex_lock(&buffer->lock);
+	/* now map it to userspace */
+	ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma);
+	mutex_unlock(&buffer->lock);
+
+	if (ret)
+		pr_err("%s: failure mapping buffer to userspace\n",
+		       __func__);
+
+	return ret;
+}
+
+static void ion_dma_buf_release(struct dma_buf *dmabuf)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+	ion_buffer_put(buffer);
+}
+
+static void *ion_dma_buf_kmap(struct dma_buf *dmabuf, unsigned long offset)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+	return buffer->vaddr + offset * PAGE_SIZE;
+}
+
+static void ion_dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long offset,
+			       void *ptr)
+{
+	return;
+}
+
+static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start,
+					size_t len,
+					enum dma_data_direction direction)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+	void *vaddr;
+
+	if (!buffer->heap->ops->map_kernel) {
+		pr_err("%s: map kernel is not implemented by this heap.\n",
+		       __func__);
+		return -ENODEV;
+	}
+
+	mutex_lock(&buffer->lock);
+	vaddr = ion_buffer_kmap_get(buffer);
+	mutex_unlock(&buffer->lock);
+	if (IS_ERR(vaddr))
+		return PTR_ERR(vaddr);
+	if (!vaddr)
+		return -ENOMEM;
+	return 0;
+}
+
+static void ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start,
+				       size_t len,
+				       enum dma_data_direction direction)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+
+	mutex_lock(&buffer->lock);
+	ion_buffer_kmap_put(buffer);
+	mutex_unlock(&buffer->lock);
+}
+
+struct dma_buf_ops dma_buf_ops = {
+	.map_dma_buf = ion_map_dma_buf,
+	.unmap_dma_buf = ion_unmap_dma_buf,
+	.mmap = ion_mmap,
+	.release = ion_dma_buf_release,
+	.begin_cpu_access = ion_dma_buf_begin_cpu_access,
+	.end_cpu_access = ion_dma_buf_end_cpu_access,
+	.kmap_atomic = ion_dma_buf_kmap,
+	.kunmap_atomic = ion_dma_buf_kunmap,
+	.kmap = ion_dma_buf_kmap,
+	.kunmap = ion_dma_buf_kunmap,
+};
+
+struct dma_buf *ion_share_dma_buf(struct ion_client *client,
+						struct ion_handle *handle)
+{
+	struct ion_buffer *buffer;
+	struct dma_buf *dmabuf;
+	bool valid_handle;
+
+	mutex_lock(&client->lock);
+	valid_handle = ion_handle_validate(client, handle);
+	mutex_unlock(&client->lock);
+	if (!valid_handle) {
+		WARN(1, "%s: invalid handle passed to share.\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	buffer = handle->buffer;
+	ion_buffer_get(buffer);
+	dmabuf = dma_buf_export(buffer, &dma_buf_ops, buffer->size, O_RDWR);
+	if (IS_ERR(dmabuf)) {
+		ion_buffer_put(buffer);
+		return dmabuf;
+	}
+
+	return dmabuf;
+}
+EXPORT_SYMBOL(ion_share_dma_buf);
+
+int ion_share_dma_buf_fd(struct ion_client *client, struct ion_handle *handle)
+{
+	struct dma_buf *dmabuf;
+	int fd;
+
+	dmabuf = ion_share_dma_buf(client, handle);
+	if (IS_ERR(dmabuf))
+		return PTR_ERR(dmabuf);
+
+	fd = dma_buf_fd(dmabuf, O_CLOEXEC);
+	if (fd < 0)
+		dma_buf_put(dmabuf);
+
+	return fd;
+}
+EXPORT_SYMBOL(ion_share_dma_buf_fd);
+
+struct ion_handle *ion_import_dma_buf(struct ion_client *client, int fd)
+{
+	struct dma_buf *dmabuf;
+	struct ion_buffer *buffer;
+	struct ion_handle *handle;
+
+	dmabuf = dma_buf_get(fd);
+	if (IS_ERR_OR_NULL(dmabuf))
+		return ERR_PTR(PTR_ERR(dmabuf));
+	/* if this memory came from ion */
+
+	if (dmabuf->ops != &dma_buf_ops) {
+		pr_err("%s: can not import dmabuf from another exporter\n",
+		       __func__);
+		dma_buf_put(dmabuf);
+		return ERR_PTR(-EINVAL);
+	}
+	buffer = dmabuf->priv;
+
+	mutex_lock(&client->lock);
+	/* if a handle exists for this buffer just take a reference to it */
+	handle = ion_handle_lookup(client, buffer);
+	if (!IS_ERR_OR_NULL(handle)) {
+		ion_handle_get(handle);
+		goto end;
+	}
+	handle = ion_handle_create(client, buffer);
+	if (IS_ERR_OR_NULL(handle))
+		goto end;
+	ion_handle_add(client, handle);
+end:
+	mutex_unlock(&client->lock);
+	dma_buf_put(dmabuf);
+	return handle;
+}
+EXPORT_SYMBOL(ion_import_dma_buf);
+
+static int ion_sync_for_device(struct ion_client *client, int fd)
+{
+	struct dma_buf *dmabuf;
+	struct ion_buffer *buffer;
+
+	dmabuf = dma_buf_get(fd);
+	if (IS_ERR_OR_NULL(dmabuf))
+		return PTR_ERR(dmabuf);
+
+	/* if this memory came from ion */
+	if (dmabuf->ops != &dma_buf_ops) {
+		pr_err("%s: can not sync dmabuf from another exporter\n",
+		       __func__);
+		dma_buf_put(dmabuf);
+		return -EINVAL;
+	}
+	buffer = dmabuf->priv;
+
+	dma_sync_sg_for_device(NULL, buffer->sg_table->sgl,
+			       buffer->sg_table->nents, DMA_BIDIRECTIONAL);
+	dma_buf_put(dmabuf);
+	return 0;
+}
+
+static long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct ion_client *client = filp->private_data;
+
+	switch (cmd) {
+	case ION_IOC_ALLOC:
+	{
+		struct ion_allocation_data data;
+
+		if (copy_from_user(&data, (void __user *)arg, sizeof(data)))
+			return -EFAULT;
+		data.handle = ion_alloc(client, data.len, data.align,
+					     data.heap_id_mask, data.flags);
+
+		if (IS_ERR(data.handle))
+			return PTR_ERR(data.handle);
+
+		if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
+			ion_free(client, data.handle);
+			return -EFAULT;
+		}
+		break;
+	}
+	case ION_IOC_FREE:
+	{
+		struct ion_handle_data data;
+		bool valid;
+
+		if (copy_from_user(&data, (void __user *)arg,
+				   sizeof(struct ion_handle_data)))
+			return -EFAULT;
+		mutex_lock(&client->lock);
+		valid = ion_handle_validate(client, data.handle);
+		mutex_unlock(&client->lock);
+		if (!valid)
+			return -EINVAL;
+		ion_free(client, data.handle);
+		break;
+	}
+	case ION_IOC_SHARE:
+	case ION_IOC_MAP:
+	{
+		struct ion_fd_data data;
+
+		if (copy_from_user(&data, (void __user *)arg, sizeof(data)))
+			return -EFAULT;
+		data.fd = ion_share_dma_buf_fd(client, data.handle);
+		if (copy_to_user((void __user *)arg, &data, sizeof(data)))
+			return -EFAULT;
+		if (data.fd < 0)
+			return data.fd;
+		break;
+	}
+	case ION_IOC_IMPORT:
+	{
+		struct ion_fd_data data;
+		int ret = 0;
+		if (copy_from_user(&data, (void __user *)arg,
+				   sizeof(struct ion_fd_data)))
+			return -EFAULT;
+		data.handle = ion_import_dma_buf(client, data.fd);
+		if (IS_ERR(data.handle)) {
+			ret = PTR_ERR(data.handle);
+			data.handle = NULL;
+		}
+		if (copy_to_user((void __user *)arg, &data,
+				 sizeof(struct ion_fd_data)))
+			return -EFAULT;
+		if (ret < 0)
+			return ret;
+		break;
+	}
+	case ION_IOC_SYNC:
+	{
+		struct ion_fd_data data;
+		if (copy_from_user(&data, (void __user *)arg,
+				   sizeof(struct ion_fd_data)))
+			return -EFAULT;
+		ion_sync_for_device(client, data.fd);
+		break;
+	}
+	case ION_IOC_CUSTOM:
+	{
+		struct ion_device *dev = client->dev;
+		struct ion_custom_data data;
+
+		if (!dev->custom_ioctl)
+			return -ENOTTY;
+		if (copy_from_user(&data, (void __user *)arg,
+				sizeof(struct ion_custom_data)))
+			return -EFAULT;
+		return dev->custom_ioctl(client, data.cmd, data.arg);
+	}
+	default:
+		return -ENOTTY;
+	}
+	return 0;
+}
+
+static int ion_release(struct inode *inode, struct file *file)
+{
+	struct ion_client *client = file->private_data;
+
+	pr_debug("%s: %d\n", __func__, __LINE__);
+	ion_client_destroy(client);
+	return 0;
+}
+
+static int ion_open(struct inode *inode, struct file *file)
+{
+	struct miscdevice *miscdev = file->private_data;
+	struct ion_device *dev = container_of(miscdev, struct ion_device, dev);
+	struct ion_client *client;
+
+	pr_debug("%s: %d\n", __func__, __LINE__);
+	client = ion_client_create(dev, "user");
+	if (IS_ERR_OR_NULL(client))
+		return PTR_ERR(client);
+	file->private_data = client;
+
+	return 0;
+}
+
+static const struct file_operations ion_fops = {
+	.owner          = THIS_MODULE,
+	.open           = ion_open,
+	.release        = ion_release,
+	.unlocked_ioctl = ion_ioctl,
+};
+
+static size_t ion_debug_heap_total(struct ion_client *client,
+				   unsigned int id)
+{
+	size_t size = 0;
+	struct rb_node *n;
+
+	mutex_lock(&client->lock);
+	for (n = rb_first(&client->handles); n; n = rb_next(n)) {
+		struct ion_handle *handle = rb_entry(n,
+						     struct ion_handle,
+						     node);
+		if (handle->buffer->heap->id == id)
+			size += handle->buffer->size;
+	}
+	mutex_unlock(&client->lock);
+	return size;
+}
+
+static int ion_debug_heap_show(struct seq_file *s, void *unused)
+{
+	struct ion_heap *heap = s->private;
+	struct ion_device *dev = heap->dev;
+	struct rb_node *n;
+	size_t total_size = 0;
+	size_t total_orphaned_size = 0;
+
+	seq_printf(s, "%16.s %16.s %16.s\n", "client", "pid", "size");
+	seq_printf(s, "----------------------------------------------------\n");
+
+	for (n = rb_first(&dev->clients); n; n = rb_next(n)) {
+		struct ion_client *client = rb_entry(n, struct ion_client,
+						     node);
+		size_t size = ion_debug_heap_total(client, heap->id);
+		if (!size)
+			continue;
+		if (client->task) {
+			char task_comm[TASK_COMM_LEN];
+
+			get_task_comm(task_comm, client->task);
+			seq_printf(s, "%16.s %16u %16lu\n", task_comm,
+				   client->pid, (unsigned long)size);
+		} else {
+			seq_printf(s, "%16.s %16u %16lu\n", client->name,
+				   client->pid, (unsigned long)size);
+		}
+	}
+	seq_printf(s, "----------------------------------------------------\n");
+	seq_printf(s, "orphaned allocations (info is from last known client):"
+		   "\n");
+	mutex_lock(&dev->buffer_lock);
+	for (n = rb_first(&dev->buffers); n; n = rb_next(n)) {
+		struct ion_buffer *buffer = rb_entry(n, struct ion_buffer,
+						     node);
+		if (buffer->heap->id != heap->id)
+			continue;
+		total_size += buffer->size;
+		if (!buffer->handle_count) {
+			seq_printf(s, "%16.s %16u %16lu %d %d\n", buffer->task_comm,
+				   buffer->pid, (unsigned long)buffer->size, buffer->kmap_cnt,
+				   atomic_read(&buffer->ref.refcount));
+			total_orphaned_size += buffer->size;
+		}
+	}
+	mutex_unlock(&dev->buffer_lock);
+	seq_printf(s, "----------------------------------------------------\n");
+	seq_printf(s, "%16.s %16lu\n", "total orphaned",
+		   (unsigned long)total_orphaned_size);
+	seq_printf(s, "%16.s %16lu\n", "total ", (unsigned long)total_size);
+	seq_printf(s, "----------------------------------------------------\n");
+
+	if (heap->debug_show)
+		heap->debug_show(heap, s, unused);
+
+	return 0;
+}
+
+static int ion_debug_heap_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ion_debug_heap_show, inode->i_private);
+}
+
+static const struct file_operations debug_heap_fops = {
+	.open = ion_debug_heap_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static size_t ion_heap_free_list_is_empty(struct ion_heap *heap)
+{
+	bool is_empty;
+
+	rt_mutex_lock(&heap->lock);
+	is_empty = list_empty(&heap->free_list);
+	rt_mutex_unlock(&heap->lock);
+
+	return is_empty;
+}
+
+static int ion_heap_deferred_free(void *data)
+{
+	struct ion_heap *heap = data;
+
+	while (true) {
+		struct ion_buffer *buffer;
+
+		wait_event_freezable(heap->waitqueue,
+				     !ion_heap_free_list_is_empty(heap));
+
+		rt_mutex_lock(&heap->lock);
+		if (list_empty(&heap->free_list)) {
+			rt_mutex_unlock(&heap->lock);
+			continue;
+		}
+		buffer = list_first_entry(&heap->free_list, struct ion_buffer,
+					  list);
+		list_del(&buffer->list);
+		rt_mutex_unlock(&heap->lock);
+		_ion_buffer_destroy(buffer);
+	}
+
+	return 0;
+}
+
+static bool ion_heap_drain_freelist(struct ion_heap *heap)
+{
+	struct ion_buffer *buffer, *tmp;
+
+	if (ion_heap_free_list_is_empty(heap))
+		return false;
+	rt_mutex_lock(&heap->lock);
+	list_for_each_entry_safe(buffer, tmp, &heap->free_list, list) {
+		list_del(&buffer->list);
+		_ion_buffer_destroy(buffer);
+	}
+	BUG_ON(!list_empty(&heap->free_list));
+	rt_mutex_unlock(&heap->lock);
+
+
+	return true;
+}
+
+void ion_device_add_heap(struct ion_device *dev, struct ion_heap *heap)
+{
+	struct sched_param param = { .sched_priority = 0 };
+
+	if (!heap->ops->allocate || !heap->ops->free || !heap->ops->map_dma ||
+	    !heap->ops->unmap_dma)
+		pr_err("%s: can not add heap with invalid ops struct.\n",
+		       __func__);
+
+	if (heap->flags & ION_HEAP_FLAG_DEFER_FREE) {
+		INIT_LIST_HEAD(&heap->free_list);
+		rt_mutex_init(&heap->lock);
+		init_waitqueue_head(&heap->waitqueue);
+		heap->task = kthread_run(ion_heap_deferred_free, heap,
+					 "%s", heap->name);
+		sched_setscheduler(heap->task, SCHED_IDLE, &param);
+		if (IS_ERR(heap->task))
+			pr_err("%s: creating thread for deferred free failed\n",
+			       __func__);
+	}
+
+	heap->dev = dev;
+	down_write(&dev->lock);
+	/* use negative heap->id to reverse the priority -- when traversing
+	   the list later attempt higher id numbers first */
+	plist_node_init(&heap->node, -heap->id);
+	plist_add(&heap->node, &dev->heaps);
+	debugfs_create_file(heap->name, 0664, dev->debug_root, heap,
+			    &debug_heap_fops);
+	up_write(&dev->lock);
+}
+
+struct ion_device *ion_device_create(long (*custom_ioctl)
+				     (struct ion_client *client,
+				      unsigned int cmd,
+				      unsigned long arg))
+{
+	struct ion_device *idev;
+	int ret;
+
+	idev = kzalloc(sizeof(struct ion_device), GFP_KERNEL);
+	if (!idev)
+		return ERR_PTR(-ENOMEM);
+
+	idev->dev.minor = MISC_DYNAMIC_MINOR;
+	idev->dev.name = "ion";
+	idev->dev.fops = &ion_fops;
+	idev->dev.parent = NULL;
+	ret = misc_register(&idev->dev);
+	if (ret) {
+		pr_err("ion: failed to register misc device.\n");
+		return ERR_PTR(ret);
+	}
+
+	idev->debug_root = debugfs_create_dir("ion", NULL);
+	if (IS_ERR_OR_NULL(idev->debug_root))
+		pr_err("ion: failed to create debug files.\n");
+
+	idev->custom_ioctl = custom_ioctl;
+	idev->buffers = RB_ROOT;
+	mutex_init(&idev->buffer_lock);
+	init_rwsem(&idev->lock);
+	plist_head_init(&idev->heaps);
+	idev->clients = RB_ROOT;
+	return idev;
+}
+
+void ion_device_destroy(struct ion_device *dev)
+{
+	misc_deregister(&dev->dev);
+	/* XXX need to free the heaps and clients ? */
+	kfree(dev);
+}
+
+void __init ion_reserve(struct ion_platform_data *data)
+{
+	int i;
+
+	for (i = 0; i < data->nr; i++) {
+		if (data->heaps[i].size == 0)
+			continue;
+
+		if (data->heaps[i].base == 0) {
+			phys_addr_t paddr;
+			paddr = memblock_alloc_base(data->heaps[i].size,
+						    data->heaps[i].align,
+						    MEMBLOCK_ALLOC_ANYWHERE);
+			if (!paddr) {
+				pr_err("%s: error allocating memblock for "
+				       "heap %d\n",
+					__func__, i);
+				continue;
+			}
+			data->heaps[i].base = paddr;
+		} else {
+			int ret = memblock_reserve(data->heaps[i].base,
+					       data->heaps[i].size);
+			if (ret)
+				pr_err("memblock reserve of %lx@%lx failed\n",
+				       (unsigned long)data->heaps[i].size,
+				       data->heaps[i].base);
+		}
+		pr_info("%s: %s reserved base %lx size %lu\n", __func__,
+			data->heaps[i].name,
+			data->heaps[i].base,
+			(unsigned long)data->heaps[i].size);
+	}
+}
diff --git a/drivers/gpu/ion/ion_heap.c b/drivers/gpu/ion/ion_heap.c
new file mode 100644
index 0000000..cf30b8a
--- /dev/null
+++ b/drivers/gpu/ion/ion_heap.c
@@ -0,0 +1,178 @@ 
+/*
+ * drivers/gpu/ion/ion_heap.c
+ *
+ * Copyright (C) 2011 Google, 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/ion.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/vmalloc.h>
+#include "ion_priv.h"
+
+void *ion_heap_map_kernel(struct ion_heap *heap,
+			  struct ion_buffer *buffer)
+{
+	struct scatterlist *sg;
+	int i, j;
+	void *vaddr;
+	pgprot_t pgprot;
+	struct sg_table *table = buffer->sg_table;
+	int npages = PAGE_ALIGN(buffer->size) / PAGE_SIZE;
+	struct page **pages = vmalloc(sizeof(struct page *) * npages);
+	struct page **tmp = pages;
+
+	if (!pages)
+		return 0;
+
+	if (buffer->flags & ION_FLAG_CACHED)
+		pgprot = PAGE_KERNEL;
+	else
+		pgprot = pgprot_writecombine(PAGE_KERNEL);
+
+	for_each_sg(table->sgl, sg, table->nents, i) {
+		int npages_this_entry = PAGE_ALIGN(sg_dma_len(sg)) / PAGE_SIZE;
+		struct page *page = sg_page(sg);
+		BUG_ON(i >= npages);
+		for (j = 0; j < npages_this_entry; j++) {
+			*(tmp++) = page++;
+		}
+	}
+	vaddr = vmap(pages, npages, VM_MAP, pgprot);
+	vfree(pages);
+
+	return vaddr;
+}
+
+void ion_heap_unmap_kernel(struct ion_heap *heap,
+			   struct ion_buffer *buffer)
+{
+	vunmap(buffer->vaddr);
+}
+
+int ion_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
+		      struct vm_area_struct *vma)
+{
+	struct sg_table *table = buffer->sg_table;
+	unsigned long addr = vma->vm_start;
+	unsigned long offset = vma->vm_pgoff * PAGE_SIZE;
+	struct scatterlist *sg;
+	int i;
+
+	for_each_sg(table->sgl, sg, table->nents, i) {
+		struct page *page = sg_page(sg);
+		unsigned long remainder = vma->vm_end - addr;
+		unsigned long len = sg_dma_len(sg);
+
+		if (offset >= sg_dma_len(sg)) {
+			offset -= sg_dma_len(sg);
+			continue;
+		} else if (offset) {
+			page += offset / PAGE_SIZE;
+			len = sg_dma_len(sg) - offset;
+			offset = 0;
+		}
+		len = min(len, remainder);
+		remap_pfn_range(vma, addr, page_to_pfn(page), len,
+				vma->vm_page_prot);
+		addr += len;
+		if (addr >= vma->vm_end)
+			return 0;
+	}
+	return 0;
+}
+
+int ion_heap_buffer_zero(struct ion_buffer *buffer)
+{
+	struct sg_table *table = buffer->sg_table;
+	pgprot_t pgprot;
+	struct scatterlist *sg;
+	struct vm_struct *vm_struct;
+	int i, j, ret = 0;
+
+	if (buffer->flags & ION_FLAG_CACHED)
+		pgprot = PAGE_KERNEL;
+	else
+		pgprot = pgprot_writecombine(PAGE_KERNEL);
+
+	vm_struct = get_vm_area(PAGE_SIZE, VM_ALLOC);
+	if (!vm_struct)
+		return -ENOMEM;
+
+	for_each_sg(table->sgl, sg, table->nents, i) {
+		struct page *page = sg_page(sg);
+		unsigned long len = sg_dma_len(sg);
+
+		for (j = 0; j < len / PAGE_SIZE; j++) {
+			struct page *sub_page = page + j;
+			struct page **pages = &sub_page;
+			ret = map_vm_area(vm_struct, pgprot, &pages);
+			if (ret)
+				goto end;
+			memset(vm_struct->addr, 0, PAGE_SIZE);
+			unmap_kernel_range((unsigned long)vm_struct->addr,
+					   PAGE_SIZE);
+		}
+	}
+end:
+	free_vm_area(vm_struct);
+	return ret;
+}
+
+struct ion_heap *ion_heap_create(struct ion_platform_heap *heap_data)
+{
+	struct ion_heap *heap = NULL;
+
+	switch (heap_data->type) {
+	case ION_HEAP_TYPE_SYSTEM_CONTIG:
+		heap = ion_system_contig_heap_create(heap_data);
+		break;
+	case ION_HEAP_TYPE_SYSTEM:
+		heap = ion_system_heap_create(heap_data);
+		break;
+	default:
+		pr_err("%s: Invalid heap type %d\n", __func__,
+		       heap_data->type);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (IS_ERR_OR_NULL(heap)) {
+		pr_err("%s: error creating heap %s type %d base %lu size %lu\n",
+		       __func__, heap_data->name, heap_data->type,
+		       heap_data->base, (unsigned long)heap_data->size);
+		return ERR_PTR(-EINVAL);
+	}
+
+	heap->name = heap_data->name;
+	heap->id = heap_data->id;
+	return heap;
+}
+
+void ion_heap_destroy(struct ion_heap *heap)
+{
+	if (!heap)
+		return;
+
+	switch (heap->type) {
+	case ION_HEAP_TYPE_SYSTEM_CONTIG:
+		ion_system_contig_heap_destroy(heap);
+		break;
+	case ION_HEAP_TYPE_SYSTEM:
+		ion_system_heap_destroy(heap);
+		break;
+	default:
+		pr_err("%s: Invalid heap type %d\n", __func__,
+		       heap->type);
+	}
+}
diff --git a/drivers/gpu/ion/ion_page_pool.c b/drivers/gpu/ion/ion_page_pool.c
new file mode 100644
index 0000000..89bef43
--- /dev/null
+++ b/drivers/gpu/ion/ion_page_pool.c
@@ -0,0 +1,282 @@ 
+/*
+ * drivers/gpu/ion/ion_mem_pool.c
+ *
+ * Copyright (C) 2011 Google, 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/debugfs.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/shrinker.h>
+#include "ion_priv.h"
+
+/* #define DEBUG_PAGE_POOL_SHRINKER */
+
+static struct plist_head pools = PLIST_HEAD_INIT(pools);
+static struct shrinker shrinker;
+
+struct ion_page_pool_item {
+	struct page *page;
+	struct list_head list;
+};
+
+static void *ion_page_pool_alloc_pages(struct ion_page_pool *pool)
+{
+	struct page *page = alloc_pages(pool->gfp_mask, pool->order);
+
+	if (!page)
+		return NULL;
+	/* this is only being used to flush the page for dma,
+	   this api is not really suitable for calling from a driver
+	   but no better way to flush a page for dma exist at this time */
+	dma_sync_single_for_device(NULL,
+					   pfn_to_dma(NULL, page_to_pfn(page)),
+					   PAGE_SIZE << pool->order,
+					   DMA_BIDIRECTIONAL);
+	return page;
+}
+
+static void ion_page_pool_free_pages(struct ion_page_pool *pool,
+				     struct page *page)
+{
+	__free_pages(page, pool->order);
+}
+
+static int ion_page_pool_add(struct ion_page_pool *pool, struct page *page)
+{
+	struct ion_page_pool_item *item;
+
+	item = kmalloc(sizeof(struct ion_page_pool_item), GFP_KERNEL);
+	if (!item)
+		return -ENOMEM;
+
+	mutex_lock(&pool->mutex);
+	item->page = page;
+	if (PageHighMem(page)) {
+		list_add_tail(&item->list, &pool->high_items);
+		pool->high_count++;
+	} else {
+		list_add_tail(&item->list, &pool->low_items);
+		pool->low_count++;
+	}
+	mutex_unlock(&pool->mutex);
+	return 0;
+}
+
+static struct page *ion_page_pool_remove(struct ion_page_pool *pool, bool high)
+{
+	struct ion_page_pool_item *item;
+	struct page *page;
+
+	if (high) {
+		BUG_ON(!pool->high_count);
+		item = list_first_entry(&pool->high_items,
+					struct ion_page_pool_item, list);
+		pool->high_count--;
+	} else {
+		BUG_ON(!pool->low_count);
+		item = list_first_entry(&pool->low_items,
+					struct ion_page_pool_item, list);
+		pool->low_count--;
+	}
+
+	list_del(&item->list);
+	page = item->page;
+	kfree(item);
+	return page;
+}
+
+void *ion_page_pool_alloc(struct ion_page_pool *pool)
+{
+	struct page *page = NULL;
+
+	BUG_ON(!pool);
+
+	mutex_lock(&pool->mutex);
+	if (pool->high_count)
+		page = ion_page_pool_remove(pool, true);
+	else if (pool->low_count)
+		page = ion_page_pool_remove(pool, false);
+	mutex_unlock(&pool->mutex);
+
+	if (!page)
+		page = ion_page_pool_alloc_pages(pool);
+
+	return page;
+}
+
+void ion_page_pool_free(struct ion_page_pool *pool, struct page* page)
+{
+	int ret;
+
+	ret = ion_page_pool_add(pool, page);
+	if (ret)
+		ion_page_pool_free_pages(pool, page);
+}
+
+#ifdef DEBUG_PAGE_POOL_SHRINKER
+static int debug_drop_pools_set(void *data, u64 val)
+{
+	struct shrink_control sc;
+	int objs;
+
+	sc.gfp_mask = -1;
+	sc.nr_to_scan = 0;
+
+	if (!val)
+		return 0;
+
+	objs = shrinker.shrink(&shrinker, &sc);
+	sc.nr_to_scan = objs;
+
+	shrinker.shrink(&shrinker, &sc);
+	return 0;
+}
+
+static int debug_drop_pools_get(void *data, u64 *val)
+{
+	struct shrink_control sc;
+	int objs;
+
+	sc.gfp_mask = -1;
+	sc.nr_to_scan = 0;
+
+	objs = shrinker.shrink(&shrinker, &sc);
+	*val = objs;
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(debug_drop_pools_fops, debug_drop_pools_get,
+                        debug_drop_pools_set, "%llu\n");
+
+static int debug_grow_pools_set(void *data, u64 val)
+{
+	struct ion_page_pool *pool;
+	struct page *page;
+
+	plist_for_each_entry(pool, &pools, list) {
+		if (val != pool->list.prio)
+			continue;
+		page = ion_page_pool_alloc_pages(pool);
+		if (page)
+			ion_page_pool_add(pool, page);
+	}
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(debug_grow_pools_fops, debug_drop_pools_get,
+			debug_grow_pools_set, "%llu\n");
+#endif
+
+static int ion_page_pool_total(bool high)
+{
+	struct ion_page_pool *pool;
+	int total = 0;
+
+	plist_for_each_entry(pool, &pools, list) {
+		total += high ? (pool->high_count + pool->low_count) *
+			(1 << pool->order) :
+			pool->low_count * (1 << pool->order);
+	}
+	return total;
+}
+
+static int ion_page_pool_shrink(struct shrinker *shrinker,
+				 struct shrink_control *sc)
+{
+	struct ion_page_pool *pool;
+	int nr_freed = 0;
+	int i;
+	bool high;
+	int nr_to_scan = sc->nr_to_scan;
+
+	high = sc->gfp_mask & __GFP_HIGHMEM;
+
+	if (nr_to_scan == 0)
+		return ion_page_pool_total(high);
+
+	plist_for_each_entry(pool, &pools, list) {
+		for (i = 0; i < nr_to_scan; i++) {
+			struct page *page;
+
+			mutex_lock(&pool->mutex);
+			if (high && pool->high_count) {
+				page = ion_page_pool_remove(pool, true);
+			} else if (pool->low_count) {
+				page = ion_page_pool_remove(pool, false);
+			} else {
+				mutex_unlock(&pool->mutex);
+				break;
+			}
+			mutex_unlock(&pool->mutex);
+			ion_page_pool_free_pages(pool, page);
+			nr_freed += (1 << pool->order);
+		}
+		nr_to_scan -= i;
+	}
+
+	return ion_page_pool_total(high);
+}
+
+struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order)
+{
+	struct ion_page_pool *pool = kmalloc(sizeof(struct ion_page_pool),
+					     GFP_KERNEL);
+	if (!pool)
+		return NULL;
+	pool->high_count = 0;
+	pool->low_count = 0;
+	INIT_LIST_HEAD(&pool->low_items);
+	INIT_LIST_HEAD(&pool->high_items);
+	pool->gfp_mask = gfp_mask;
+	pool->order = order;
+	mutex_init(&pool->mutex);
+	plist_node_init(&pool->list, order);
+	plist_add(&pool->list, &pools);
+
+	return pool;
+}
+
+void ion_page_pool_destroy(struct ion_page_pool *pool)
+{
+	plist_del(&pool->list, &pools);
+	kfree(pool);
+}
+
+static int __init ion_page_pool_init(void)
+{
+	shrinker.shrink = ion_page_pool_shrink;
+	shrinker.seeks = DEFAULT_SEEKS;
+	shrinker.batch = 0;
+	register_shrinker(&shrinker);
+#ifdef DEBUG_PAGE_POOL_SHRINKER
+	debugfs_create_file("ion_pools_shrink", 0644, NULL, NULL,
+			    &debug_drop_pools_fops);
+	debugfs_create_file("ion_pools_grow", 0644, NULL, NULL,
+			    &debug_grow_pools_fops);
+#endif
+	return 0;
+}
+
+static void __exit ion_page_pool_exit(void)
+{
+	unregister_shrinker(&shrinker);
+}
+
+module_init(ion_page_pool_init);
+module_exit(ion_page_pool_exit);
diff --git a/drivers/gpu/ion/ion_priv.h b/drivers/gpu/ion/ion_priv.h
new file mode 100644
index 0000000..2146a65
--- /dev/null
+++ b/drivers/gpu/ion/ion_priv.h
@@ -0,0 +1,302 @@ 
+/*
+ * drivers/gpu/ion/ion_priv.h
+ *
+ * Copyright (C) 2011 Google, 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.
+ *
+ */
+
+#ifndef _ION_PRIV_H
+#define _ION_PRIV_H
+
+#include <linux/ion.h>
+#include <linux/kref.h>
+#include <linux/mm_types.h>
+#include <linux/mutex.h>
+#include <linux/rbtree.h>
+#include <linux/sched.h>
+#include <linux/shrinker.h>
+#include <linux/types.h>
+
+struct ion_buffer *ion_handle_buffer(struct ion_handle *handle);
+
+/**
+ * struct ion_buffer - metadata for a particular buffer
+ * @ref:		refernce count
+ * @node:		node in the ion_device buffers tree
+ * @dev:		back pointer to the ion_device
+ * @heap:		back pointer to the heap the buffer came from
+ * @flags:		buffer specific flags
+ * @size:		size of the buffer
+ * @priv_virt:		private data to the buffer representable as
+ *			a void *
+ * @priv_phys:		private data to the buffer representable as
+ *			an ion_phys_addr_t (and someday a phys_addr_t)
+ * @lock:		protects the buffers cnt fields
+ * @kmap_cnt:		number of times the buffer is mapped to the kernel
+ * @vaddr:		the kenrel mapping if kmap_cnt is not zero
+ * @dmap_cnt:		number of times the buffer is mapped for dma
+ * @sg_table:		the sg table for the buffer if dmap_cnt is not zero
+ * @dirty:		bitmask representing which pages of this buffer have
+ *			been dirtied by the cpu and need cache maintenance
+ *			before dma
+ * @vmas:		list of vma's mapping this buffer
+ * @handle_count:	count of handles referencing this buffer
+ * @task_comm:		taskcomm of last client to reference this buffer in a
+ *			handle, used for debugging
+ * @pid:		pid of last client to reference this buffer in a
+ *			handle, used for debugging
+*/
+struct ion_buffer {
+	struct kref ref;
+	union {
+		struct rb_node node;
+		struct list_head list;
+	};
+	struct ion_device *dev;
+	struct ion_heap *heap;
+	unsigned long flags;
+	size_t size;
+	union {
+		void *priv_virt;
+		ion_phys_addr_t priv_phys;
+	};
+	struct mutex lock;
+	int kmap_cnt;
+	void *vaddr;
+	int dmap_cnt;
+	struct sg_table *sg_table;
+	unsigned long *dirty;
+	struct list_head vmas;
+	/* used to track orphaned buffers */
+	int handle_count;
+	char task_comm[TASK_COMM_LEN];
+	pid_t pid;
+};
+
+/**
+ * struct ion_heap_ops - ops to operate on a given heap
+ * @allocate:		allocate memory
+ * @free:		free memory
+ * @phys		get physical address of a buffer (only define on
+ *			physically contiguous heaps)
+ * @map_dma		map the memory for dma to a scatterlist
+ * @unmap_dma		unmap the memory for dma
+ * @map_kernel		map memory to the kernel
+ * @unmap_kernel	unmap memory to the kernel
+ * @map_user		map memory to userspace
+ */
+struct ion_heap_ops {
+	int (*allocate) (struct ion_heap *heap,
+			 struct ion_buffer *buffer, unsigned long len,
+			 unsigned long align, unsigned long flags);
+	void (*free) (struct ion_buffer *buffer);
+	int (*phys) (struct ion_heap *heap, struct ion_buffer *buffer,
+		     ion_phys_addr_t *addr, size_t *len);
+	struct sg_table *(*map_dma) (struct ion_heap *heap,
+					struct ion_buffer *buffer);
+	void (*unmap_dma) (struct ion_heap *heap, struct ion_buffer *buffer);
+	void * (*map_kernel) (struct ion_heap *heap, struct ion_buffer *buffer);
+	void (*unmap_kernel) (struct ion_heap *heap, struct ion_buffer *buffer);
+	int (*map_user) (struct ion_heap *mapper, struct ion_buffer *buffer,
+			 struct vm_area_struct *vma);
+};
+
+/**
+ * heap flags - flags between the heaps and core ion code
+ */
+#define ION_HEAP_FLAG_DEFER_FREE (1 << 0)
+
+/**
+ * struct ion_heap - represents a heap in the system
+ * @node:		rb node to put the heap on the device's tree of heaps
+ * @dev:		back pointer to the ion_device
+ * @type:		type of heap
+ * @ops:		ops struct as above
+ * @flags:		flags
+ * @id:			id of heap, also indicates priority of this heap when
+ *			allocating.  These are specified by platform data and
+ *			MUST be unique
+ * @name:		used for debugging
+ * @free_list:		free list head if deferred free is used
+ * @lock:		protects the free list
+ * @waitqueue:		queue to wait on from deferred free thread
+ * @task:		task struct of deferred free thread
+ * @debug_show:		called when heap debug file is read to add any
+ *			heap specific debug info to output
+ *
+ * Represents a pool of memory from which buffers can be made.  In some
+ * systems the only heap is regular system memory allocated via vmalloc.
+ * On others, some blocks might require large physically contiguous buffers
+ * that are allocated from a specially reserved heap.
+ */
+struct ion_heap {
+	struct plist_node node;
+	struct ion_device *dev;
+	enum ion_heap_type type;
+	struct ion_heap_ops *ops;
+	unsigned long flags;
+	unsigned int id;
+	const char *name;
+	struct list_head free_list;
+	struct rt_mutex lock;
+	wait_queue_head_t waitqueue;
+	struct task_struct *task;
+	int (*debug_show)(struct ion_heap *heap, struct seq_file *, void *);
+};
+
+/**
+ * ion_buffer_cached - this ion buffer is cached
+ * @buffer:		buffer
+ *
+ * indicates whether this ion buffer is cached
+ */
+bool ion_buffer_cached(struct ion_buffer *buffer);
+
+/**
+ * ion_buffer_fault_user_mappings - fault in user mappings of this buffer
+ * @buffer:		buffer
+ *
+ * indicates whether userspace mappings of this buffer will be faulted
+ * in, this can affect how buffers are allocated from the heap.
+ */
+bool ion_buffer_fault_user_mappings(struct ion_buffer *buffer);
+
+/**
+ * ion_device_create - allocates and returns an ion device
+ * @custom_ioctl:	arch specific ioctl function if applicable
+ *
+ * returns a valid device or -PTR_ERR
+ */
+struct ion_device *ion_device_create(long (*custom_ioctl)
+				     (struct ion_client *client,
+				      unsigned int cmd,
+				      unsigned long arg));
+
+/**
+ * ion_device_destroy - free and device and it's resource
+ * @dev:		the device
+ */
+void ion_device_destroy(struct ion_device *dev);
+
+/**
+ * ion_device_add_heap - adds a heap to the ion device
+ * @dev:		the device
+ * @heap:		the heap to add
+ */
+void ion_device_add_heap(struct ion_device *dev, struct ion_heap *heap);
+
+/**
+ * some helpers for common operations on buffers using the sg_table
+ * and vaddr fields
+ */
+void *ion_heap_map_kernel(struct ion_heap *, struct ion_buffer *);
+void ion_heap_unmap_kernel(struct ion_heap *, struct ion_buffer *);
+int ion_heap_map_user(struct ion_heap *, struct ion_buffer *,
+			struct vm_area_struct *);
+int ion_heap_buffer_zero(struct ion_buffer *buffer);
+
+
+/**
+ * functions for creating and destroying the built in ion heaps.
+ * architectures can add their own custom architecture specific
+ * heaps as appropriate.
+ */
+
+struct ion_heap *ion_heap_create(struct ion_platform_heap *);
+void ion_heap_destroy(struct ion_heap *);
+struct ion_heap *ion_system_heap_create(struct ion_platform_heap *);
+void ion_system_heap_destroy(struct ion_heap *);
+
+struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *);
+void ion_system_contig_heap_destroy(struct ion_heap *);
+
+struct ion_heap *ion_carveout_heap_create(struct ion_platform_heap *);
+void ion_carveout_heap_destroy(struct ion_heap *);
+
+struct ion_heap *ion_chunk_heap_create(struct ion_platform_heap *);
+void ion_chunk_heap_destroy(struct ion_heap *);
+/**
+ * kernel api to allocate/free from carveout -- used when carveout is
+ * used to back an architecture specific custom heap
+ */
+ion_phys_addr_t ion_carveout_allocate(struct ion_heap *heap, unsigned long size,
+				      unsigned long align);
+void ion_carveout_free(struct ion_heap *heap, ion_phys_addr_t addr,
+		       unsigned long size);
+/**
+ * The carveout heap returns physical addresses, since 0 may be a valid
+ * physical address, this is used to indicate allocation failed
+ */
+#define ION_CARVEOUT_ALLOCATE_FAIL -1
+
+/**
+ * functions for creating and destroying a heap pool -- allows you
+ * to keep a pool of pre allocated memory to use from your heap.  Keeping
+ * a pool of memory that is ready for dma, ie any cached mapping have been
+ * invalidated from the cache, provides a significant peformance benefit on
+ * many systems */
+
+/**
+ * struct ion_page_pool - pagepool struct
+ * @high_count:		number of highmem items in the pool
+ * @low_count:		number of lowmem items in the pool
+ * @high_items:		list of highmem items
+ * @low_items:		list of lowmem items
+ * @shrinker:		a shrinker for the items
+ * @mutex:		lock protecting this struct and especially the count
+ *			item list
+ * @alloc:		function to be used to allocate pageory when the pool
+ *			is empty
+ * @free:		function to be used to free pageory back to the system
+ *			when the shrinker fires
+ * @gfp_mask:		gfp_mask to use from alloc
+ * @order:		order of pages in the pool
+ * @list:		plist node for list of pools
+ *
+ * Allows you to keep a pool of pre allocated pages to use from your heap.
+ * Keeping a pool of pages that is ready for dma, ie any cached mapping have
+ * been invalidated from the cache, provides a significant peformance benefit
+ * on many systems
+ */
+struct ion_page_pool {
+	int high_count;
+	int low_count;
+	struct list_head high_items;
+	struct list_head low_items;
+	struct mutex mutex;
+	void *(*alloc)(struct ion_page_pool *pool);
+	void (*free)(struct ion_page_pool *pool, struct page *page);
+	gfp_t gfp_mask;
+	unsigned int order;
+	struct plist_node list;
+};
+
+struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order);
+void ion_page_pool_destroy(struct ion_page_pool *);
+void *ion_page_pool_alloc(struct ion_page_pool *);
+void ion_page_pool_free(struct ion_page_pool *, struct page *);
+
+
+/* Not all arches define these */
+#ifndef __phys_to_pfn
+   #define	__phys_to_pfn(paddr)	((unsigned long)((paddr) >> PAGE_SHIFT)) 
+#endif
+#ifndef phys_to_page
+    #define phys_to_page(phys)	(pfn_to_page(__phys_to_pfn(phys)))
+#endif
+#ifndef pfn_to_dma
+    #define pfn_to_dma(dev, pfn) (dma_addr_t)(pfn)
+#endif
+
+
+
+#endif /* _ION_PRIV_H */
diff --git a/drivers/gpu/ion/ion_system_heap.c b/drivers/gpu/ion/ion_system_heap.c
new file mode 100644
index 0000000..7e5aca3
--- /dev/null
+++ b/drivers/gpu/ion/ion_system_heap.c
@@ -0,0 +1,418 @@ 
+/*
+ * drivers/gpu/ion/ion_system_heap.c
+ *
+ * Copyright (C) 2011 Google, 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 <asm/page.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/ion.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include "ion_priv.h"
+
+static unsigned int high_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO |
+					    __GFP_NOWARN | __GFP_NORETRY) &
+					   ~__GFP_WAIT;
+static unsigned int low_order_gfp_flags  = (GFP_HIGHUSER | __GFP_ZERO |
+					 __GFP_NOWARN);
+static const unsigned int orders[] = {8, 4, 0};
+static const int num_orders = ARRAY_SIZE(orders);
+static int order_to_index(unsigned int order)
+{
+	int i;
+	for (i = 0; i < num_orders; i++)
+		if (order == orders[i])
+			return i;
+	BUG();
+	return -1;
+}
+
+static unsigned int order_to_size(int order)
+{
+	return PAGE_SIZE << order;
+}
+
+struct ion_system_heap {
+	struct ion_heap heap;
+	struct ion_page_pool **pools;
+};
+
+struct page_info {
+	struct page *page;
+	unsigned int order;
+	struct list_head list;
+};
+
+static struct page *alloc_buffer_page(struct ion_system_heap *heap,
+				      struct ion_buffer *buffer,
+				      unsigned long order)
+{
+	bool cached = ion_buffer_cached(buffer);
+	bool split_pages = ion_buffer_fault_user_mappings(buffer);
+	struct ion_page_pool *pool = heap->pools[order_to_index(order)];
+	struct page *page;
+
+	if (!cached) {
+		page = ion_page_pool_alloc(pool);
+	} else {
+		gfp_t gfp_flags = low_order_gfp_flags;
+
+		if (order > 4)
+			gfp_flags = high_order_gfp_flags;
+		page = alloc_pages(gfp_flags, order);
+		if (!page)
+			return 0;
+		dma_sync_single_for_device(NULL,
+			pfn_to_dma(NULL, page_to_pfn(page)),
+			PAGE_SIZE << order, DMA_BIDIRECTIONAL);
+	}
+	if (!page)
+		return 0;
+
+	if (split_pages)
+		split_page(page, order);
+	return page;
+}
+
+static void free_buffer_page(struct ion_system_heap *heap,
+			     struct ion_buffer *buffer, struct page *page,
+			     unsigned int order)
+{
+	bool cached = ion_buffer_cached(buffer);
+	bool split_pages = ion_buffer_fault_user_mappings(buffer);
+	int i;
+
+	if (!cached) {
+		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
+		ion_page_pool_free(pool, page);
+	} else if (split_pages) {
+		for (i = 0; i < (1 << order); i++)
+			__free_page(page + i);
+	} else {
+		__free_pages(page, order);
+	}
+}
+
+
+static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
+						 struct ion_buffer *buffer,
+						 unsigned long size,
+						 unsigned int max_order)
+{
+	struct page *page;
+	struct page_info *info;
+	int i;
+
+	for (i = 0; i < num_orders; i++) {
+		if (size < order_to_size(orders[i]))
+			continue;
+		if (max_order < orders[i])
+			continue;
+
+		page = alloc_buffer_page(heap, buffer, orders[i]);
+		if (!page)
+			continue;
+
+		info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
+		info->page = page;
+		info->order = orders[i];
+		return info;
+	}
+	return NULL;
+}
+
+static int ion_system_heap_allocate(struct ion_heap *heap,
+				     struct ion_buffer *buffer,
+				     unsigned long size, unsigned long align,
+				     unsigned long flags)
+{
+	struct ion_system_heap *sys_heap = container_of(heap,
+							struct ion_system_heap,
+							heap);
+	struct sg_table *table;
+	struct scatterlist *sg;
+	int ret;
+	struct list_head pages;
+	struct page_info *info, *tmp_info;
+	int i = 0;
+	long size_remaining = PAGE_ALIGN(size);
+	unsigned int max_order = orders[0];
+	bool split_pages = ion_buffer_fault_user_mappings(buffer);
+
+	INIT_LIST_HEAD(&pages);
+	while (size_remaining > 0) {
+		info = alloc_largest_available(sys_heap, buffer, size_remaining, max_order);
+		if (!info)
+			goto err;
+		list_add_tail(&info->list, &pages);
+		size_remaining -= (1 << info->order) * PAGE_SIZE;
+		max_order = info->order;
+		i++;
+	}
+
+	table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
+	if (!table)
+		goto err;
+
+	if (split_pages)
+		ret = sg_alloc_table(table, PAGE_ALIGN(size) / PAGE_SIZE,
+				     GFP_KERNEL);
+	else
+		ret = sg_alloc_table(table, i, GFP_KERNEL);
+
+	if (ret)
+		goto err1;
+
+	sg = table->sgl;
+	list_for_each_entry_safe(info, tmp_info, &pages, list) {
+		struct page *page = info->page;
+		if (split_pages) {
+			for (i = 0; i < (1 << info->order); i++) {
+				sg_set_page(sg, page + i, PAGE_SIZE, 0);
+				sg = sg_next(sg);
+			}
+		} else {
+			sg_set_page(sg, page, (1 << info->order) * PAGE_SIZE,
+				    0);
+			sg = sg_next(sg);
+		}
+		list_del(&info->list);
+		kfree(info);
+	}
+
+	buffer->priv_virt = table;
+	return 0;
+err1:
+	kfree(table);
+err:
+	list_for_each_entry(info, &pages, list) {
+		free_buffer_page(sys_heap, buffer, info->page, info->order);
+		kfree(info);
+	}
+	return -ENOMEM;
+}
+
+void ion_system_heap_free(struct ion_buffer *buffer)
+{
+	struct ion_heap *heap = buffer->heap;
+	struct ion_system_heap *sys_heap = container_of(heap,
+							struct ion_system_heap,
+							heap);
+	struct sg_table *table = buffer->sg_table;
+	bool cached = ion_buffer_cached(buffer);
+	struct scatterlist *sg;
+	LIST_HEAD(pages);
+	int i;
+
+	/* uncached pages come from the page pools, zero them before returning
+	   for security purposes (other allocations are zerod at alloc time */
+	if (!cached)
+		ion_heap_buffer_zero(buffer);
+
+	for_each_sg(table->sgl, sg, table->nents, i)
+		free_buffer_page(sys_heap, buffer, sg_page(sg),
+				get_order(sg_dma_len(sg)));
+	sg_free_table(table);
+	kfree(table);
+}
+
+struct sg_table *ion_system_heap_map_dma(struct ion_heap *heap,
+					 struct ion_buffer *buffer)
+{
+	return buffer->priv_virt;
+}
+
+void ion_system_heap_unmap_dma(struct ion_heap *heap,
+			       struct ion_buffer *buffer)
+{
+	return;
+}
+
+static struct ion_heap_ops system_heap_ops = {
+	.allocate = ion_system_heap_allocate,
+	.free = ion_system_heap_free,
+	.map_dma = ion_system_heap_map_dma,
+	.unmap_dma = ion_system_heap_unmap_dma,
+	.map_kernel = ion_heap_map_kernel,
+	.unmap_kernel = ion_heap_unmap_kernel,
+	.map_user = ion_heap_map_user,
+};
+
+static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
+				      void *unused)
+{
+
+	struct ion_system_heap *sys_heap = container_of(heap,
+							struct ion_system_heap,
+							heap);
+	int i;
+	for (i = 0; i < num_orders; i++) {
+		struct ion_page_pool *pool = sys_heap->pools[i];
+		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
+			   pool->high_count, pool->order,
+			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
+		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
+			   pool->low_count, pool->order,
+			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
+	}
+	return 0;
+}
+
+struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
+{
+	struct ion_system_heap *heap;
+	int i;
+
+	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
+	if (!heap)
+		return ERR_PTR(-ENOMEM);
+	heap->heap.ops = &system_heap_ops;
+	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
+	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
+	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
+			      GFP_KERNEL);
+	if (!heap->pools)
+		goto err_alloc_pools;
+	for (i = 0; i < num_orders; i++) {
+		struct ion_page_pool *pool;
+		gfp_t gfp_flags = low_order_gfp_flags;
+
+		if (orders[i] > 4)
+			gfp_flags = high_order_gfp_flags;
+		pool = ion_page_pool_create(gfp_flags, orders[i]);
+		if (!pool)
+			goto err_create_pool;
+		heap->pools[i] = pool;
+	}
+	heap->heap.debug_show = ion_system_heap_debug_show;
+	return &heap->heap;
+err_create_pool:
+	for (i = 0; i < num_orders; i++)
+		if (heap->pools[i])
+			ion_page_pool_destroy(heap->pools[i]);
+	kfree(heap->pools);
+err_alloc_pools:
+	kfree(heap);
+	return ERR_PTR(-ENOMEM);
+}
+
+void ion_system_heap_destroy(struct ion_heap *heap)
+{
+	struct ion_system_heap *sys_heap = container_of(heap,
+							struct ion_system_heap,
+							heap);
+	int i;
+
+	for (i = 0; i < num_orders; i++)
+		ion_page_pool_destroy(sys_heap->pools[i]);
+	kfree(sys_heap->pools);
+	kfree(sys_heap);
+}
+
+static int ion_system_contig_heap_allocate(struct ion_heap *heap,
+					   struct ion_buffer *buffer,
+					   unsigned long len,
+					   unsigned long align,
+					   unsigned long flags)
+{
+	buffer->priv_virt = kzalloc(len, GFP_KERNEL);
+	if (!buffer->priv_virt)
+		return -ENOMEM;
+	return 0;
+}
+
+void ion_system_contig_heap_free(struct ion_buffer *buffer)
+{
+	kfree(buffer->priv_virt);
+}
+
+static int ion_system_contig_heap_phys(struct ion_heap *heap,
+				       struct ion_buffer *buffer,
+				       ion_phys_addr_t *addr, size_t *len)
+{
+	*addr = virt_to_phys(buffer->priv_virt);
+	*len = buffer->size;
+	return 0;
+}
+
+struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
+						struct ion_buffer *buffer)
+{
+	struct sg_table *table;
+	int ret;
+
+	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
+	if (!table)
+		return ERR_PTR(-ENOMEM);
+	ret = sg_alloc_table(table, 1, GFP_KERNEL);
+	if (ret) {
+		kfree(table);
+		return ERR_PTR(ret);
+	}
+	sg_set_page(table->sgl, virt_to_page(buffer->priv_virt), buffer->size,
+		    0);
+	return table;
+}
+
+void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
+				      struct ion_buffer *buffer)
+{
+	sg_free_table(buffer->sg_table);
+	kfree(buffer->sg_table);
+}
+
+int ion_system_contig_heap_map_user(struct ion_heap *heap,
+				    struct ion_buffer *buffer,
+				    struct vm_area_struct *vma)
+{
+	unsigned long pfn = __phys_to_pfn(virt_to_phys(buffer->priv_virt));
+	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
+			       vma->vm_end - vma->vm_start,
+			       vma->vm_page_prot);
+
+}
+
+static struct ion_heap_ops kmalloc_ops = {
+	.allocate = ion_system_contig_heap_allocate,
+	.free = ion_system_contig_heap_free,
+	.phys = ion_system_contig_heap_phys,
+	.map_dma = ion_system_contig_heap_map_dma,
+	.unmap_dma = ion_system_contig_heap_unmap_dma,
+	.map_kernel = ion_heap_map_kernel,
+	.unmap_kernel = ion_heap_unmap_kernel,
+	.map_user = ion_system_contig_heap_map_user,
+};
+
+struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
+{
+	struct ion_heap *heap;
+
+	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
+	if (!heap)
+		return ERR_PTR(-ENOMEM);
+	heap->ops = &kmalloc_ops;
+	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
+	return heap;
+}
+
+void ion_system_contig_heap_destroy(struct ion_heap *heap)
+{
+	kfree(heap);
+}
+
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index d71d60f..58e1483 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -23,6 +23,8 @@  source "drivers/gpu/drm/Kconfig"
 
 source "drivers/gpu/host1x/Kconfig"
 
+source "drivers/gpu/ion/Kconfig"
+
 config VGASTATE
        tristate
        default n
diff --git a/include/linux/ion.h b/include/linux/ion.h
new file mode 100644
index 0000000..db46b19
--- /dev/null
+++ b/include/linux/ion.h
@@ -0,0 +1,365 @@ 
+/*
+ * include/linux/ion.h
+ *
+ * Copyright (C) 2011 Google, 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.
+ *
+ */
+
+#ifndef _LINUX_ION_H
+#define _LINUX_ION_H
+
+#include <linux/types.h>
+
+struct ion_handle;
+/**
+ * enum ion_heap_types - list of all possible types of heaps
+ * @ION_HEAP_TYPE_SYSTEM:	 memory allocated via vmalloc
+ * @ION_HEAP_TYPE_SYSTEM_CONTIG: memory allocated via kmalloc
+ * @ION_NUM_HEAPS:		 helper for iterating over heaps, a bit mask
+ * 				 is used to identify the heaps, so only 32
+ * 				 total heap types are supported
+ */
+enum ion_heap_type {
+	ION_HEAP_TYPE_SYSTEM,
+	ION_HEAP_TYPE_SYSTEM_CONTIG,
+	ION_NUM_HEAPS = 16,
+};
+
+#define ION_HEAP_SYSTEM_MASK		(1 << ION_HEAP_TYPE_SYSTEM)
+#define ION_HEAP_SYSTEM_CONTIG_MASK	(1 << ION_HEAP_TYPE_SYSTEM_CONTIG)
+
+#define ION_NUM_HEAP_IDS		sizeof(unsigned int) * 8
+
+/**
+ * allocation flags - the lower 16 bits are used by core ion, the upper 16
+ * bits are reserved for use by the heaps themselves.
+ */
+#define ION_FLAG_CACHED 1		/* mappings of this buffer should be
+					   cached, ion will do cache
+					   maintenance when the buffer is
+					   mapped for dma */
+#define ION_FLAG_CACHED_NEEDS_SYNC 2	/* mappings of this buffer will created
+					   at mmap time, if this is set
+					   caches must be managed manually */
+
+#ifdef __KERNEL__
+struct ion_device;
+struct ion_heap;
+struct ion_mapper;
+struct ion_client;
+struct ion_buffer;
+
+/* This should be removed some day when phys_addr_t's are fully
+   plumbed in the kernel, and all instances of ion_phys_addr_t should
+   be converted to phys_addr_t.  For the time being many kernel interfaces
+   do not accept phys_addr_t's that would have to */
+#define ion_phys_addr_t unsigned long
+
+/**
+ * struct ion_platform_heap - defines a heap in the given platform
+ * @type:	type of the heap from ion_heap_type enum
+ * @id:		unique identifier for heap.  When allocating higher numbers
+ * 		will be allocated from first.  At allocation these are passed
+ *		as a bit mask and therefore can not exceed ION_NUM_HEAP_IDS.
+ * @name:	used for debug purposes
+ * @base:	base address of heap in physical memory if applicable
+ * @size:	size of the heap in bytes if applicable
+ * @align:	required alignment in physical memory if applicable
+ * @priv:	private info passed from the board file
+ *
+ * Provided by the board file.
+ */
+struct ion_platform_heap {
+	enum ion_heap_type type;
+	unsigned int id;
+	const char *name;
+	ion_phys_addr_t base;
+	size_t size;
+	ion_phys_addr_t align;
+	void *priv;
+};
+
+/**
+ * struct ion_platform_data - array of platform heaps passed from board file
+ * @nr:		number of structures in the array
+ * @heaps:	array of platform_heap structions
+ *
+ * Provided by the board file in the form of platform data to a platform device.
+ */
+struct ion_platform_data {
+	int nr;
+	struct ion_platform_heap heaps[];
+};
+
+/**
+ * ion_reserve() - reserve memory for ion heaps if applicable
+ * @data:	platform data specifying starting physical address and
+ *		size
+ *
+ * Calls memblock reserve to set aside memory for heaps that are
+ * located at specific memory addresses or of specfic sizes not
+ * managed by the kernel
+ */
+void ion_reserve(struct ion_platform_data *data);
+
+/**
+ * ion_client_create() -  allocate a client and returns it
+ * @dev:		the global ion device
+ * @heap_type_mask:	mask of heaps this client can allocate from
+ * @name:		used for debugging
+ */
+struct ion_client *ion_client_create(struct ion_device *dev,
+				     const char *name);
+
+/**
+ * ion_client_destroy() -  free's a client and all it's handles
+ * @client:	the client
+ *
+ * Free the provided client and all it's resources including
+ * any handles it is holding.
+ */
+void ion_client_destroy(struct ion_client *client);
+
+/**
+ * ion_alloc - allocate ion memory
+ * @client:		the client
+ * @len:		size of the allocation
+ * @align:		requested allocation alignment, lots of hardware blocks
+ *			have alignment requirements of some kind
+ * @heap_id_mask:	mask of heaps to allocate from, if multiple bits are set
+ *			heaps will be tried in order from highest to lowest
+ *			id
+ * @flags:		heap flags, the low 16 bits are consumed by ion, the
+ *			high 16 bits are passed on to the respective heap and
+ *			can be heap custom
+ *
+ * Allocate memory in one of the heaps provided in heap mask and return
+ * an opaque handle to it.
+ */
+struct ion_handle *ion_alloc(struct ion_client *client, size_t len,
+			     size_t align, unsigned int heap_id_mask,
+			     unsigned int flags);
+
+/**
+ * ion_free - free a handle
+ * @client:	the client
+ * @handle:	the handle to free
+ *
+ * Free the provided handle.
+ */
+void ion_free(struct ion_client *client, struct ion_handle *handle);
+
+/**
+ * ion_phys - returns the physical address and len of a handle
+ * @client:	the client
+ * @handle:	the handle
+ * @addr:	a pointer to put the address in
+ * @len:	a pointer to put the length in
+ *
+ * This function queries the heap for a particular handle to get the
+ * handle's physical address.  It't output is only correct if
+ * a heap returns physically contiguous memory -- in other cases
+ * this api should not be implemented -- ion_sg_table should be used
+ * instead.  Returns -EINVAL if the handle is invalid.  This has
+ * no implications on the reference counting of the handle --
+ * the returned value may not be valid if the caller is not
+ * holding a reference.
+ */
+int ion_phys(struct ion_client *client, struct ion_handle *handle,
+	     ion_phys_addr_t *addr, size_t *len);
+
+/**
+ * ion_map_dma - return an sg_table describing a handle
+ * @client:	the client
+ * @handle:	the handle
+ *
+ * This function returns the sg_table describing
+ * a particular ion handle.
+ */
+struct sg_table *ion_sg_table(struct ion_client *client,
+			      struct ion_handle *handle);
+
+/**
+ * ion_map_kernel - create mapping for the given handle
+ * @client:	the client
+ * @handle:	handle to map
+ *
+ * Map the given handle into the kernel and return a kernel address that
+ * can be used to access this address.
+ */
+void *ion_map_kernel(struct ion_client *client, struct ion_handle *handle);
+
+/**
+ * ion_unmap_kernel() - destroy a kernel mapping for a handle
+ * @client:	the client
+ * @handle:	handle to unmap
+ */
+void ion_unmap_kernel(struct ion_client *client, struct ion_handle *handle);
+
+/**
+ * ion_share_dma_buf() - share buffer as dma-buf
+ * @client:	the client
+ * @handle:	the handle
+ */
+struct dma_buf *ion_share_dma_buf(struct ion_client *client,
+						struct ion_handle *handle);
+
+/**
+ * ion_share_dma_buf_fd() - given an ion client, create a dma-buf fd
+ * @client:	the client
+ * @handle:	the handle
+ */
+int ion_share_dma_buf_fd(struct ion_client *client, struct ion_handle *handle);
+
+/**
+ * ion_import_dma_buf() - given an dma-buf fd from the ion exporter get handle
+ * @client:	the client
+ * @fd:		the dma-buf fd
+ *
+ * Given an dma-buf fd that was allocated through ion via ion_share_dma_buf,
+ * import that fd and return a handle representing it.  If a dma-buf from
+ * another exporter is passed in this function will return ERR_PTR(-EINVAL)
+ */
+struct ion_handle *ion_import_dma_buf(struct ion_client *client, int fd);
+
+#endif /* __KERNEL__ */
+
+/**
+ * DOC: Ion Userspace API
+ *
+ * create a client by opening /dev/ion
+ * most operations handled via following ioctls
+ *
+ */
+
+/**
+ * struct ion_allocation_data - metadata passed from userspace for allocations
+ * @len:		size of the allocation
+ * @align:		required alignment of the allocation
+ * @heap_id_mask:	mask of heap ids to allocate from
+ * @flags:		flags passed to heap
+ * @handle:		pointer that will be populated with a cookie to use to 
+ *			refer to this allocation
+ *
+ * Provided by userspace as an argument to the ioctl
+ */
+struct ion_allocation_data {
+	size_t len;
+	size_t align;
+	unsigned int heap_id_mask;
+	unsigned int flags;
+	struct ion_handle *handle;
+};
+
+/**
+ * struct ion_fd_data - metadata passed to/from userspace for a handle/fd pair
+ * @handle:	a handle
+ * @fd:		a file descriptor representing that handle
+ *
+ * For ION_IOC_SHARE or ION_IOC_MAP userspace populates the handle field with
+ * the handle returned from ion alloc, and the kernel returns the file
+ * descriptor to share or map in the fd field.  For ION_IOC_IMPORT, userspace
+ * provides the file descriptor and the kernel returns the handle.
+ */
+struct ion_fd_data {
+	struct ion_handle *handle;
+	int fd;
+};
+
+/**
+ * struct ion_handle_data - a handle passed to/from the kernel
+ * @handle:	a handle
+ */
+struct ion_handle_data {
+	struct ion_handle *handle;
+};
+
+/**
+ * struct ion_custom_data - metadata passed to/from userspace for a custom ioctl
+ * @cmd:	the custom ioctl function to call
+ * @arg:	additional data to pass to the custom ioctl, typically a user
+ *		pointer to a predefined structure
+ *
+ * This works just like the regular cmd and arg fields of an ioctl.
+ */
+struct ion_custom_data {
+	unsigned int cmd;
+	unsigned long arg;
+};
+
+#define ION_IOC_MAGIC		'I'
+
+/**
+ * DOC: ION_IOC_ALLOC - allocate memory
+ *
+ * Takes an ion_allocation_data struct and returns it with the handle field
+ * populated with the opaque handle for the allocation.
+ */
+#define ION_IOC_ALLOC		_IOWR(ION_IOC_MAGIC, 0, \
+				      struct ion_allocation_data)
+
+/**
+ * DOC: ION_IOC_FREE - free memory
+ *
+ * Takes an ion_handle_data struct and frees the handle.
+ */
+#define ION_IOC_FREE		_IOWR(ION_IOC_MAGIC, 1, struct ion_handle_data)
+
+/**
+ * DOC: ION_IOC_MAP - get a file descriptor to mmap
+ *
+ * Takes an ion_fd_data struct with the handle field populated with a valid
+ * opaque handle.  Returns the struct with the fd field set to a file
+ * descriptor open in the current address space.  This file descriptor
+ * can then be used as an argument to mmap.
+ */
+#define ION_IOC_MAP		_IOWR(ION_IOC_MAGIC, 2, struct ion_fd_data)
+
+/**
+ * DOC: ION_IOC_SHARE - creates a file descriptor to use to share an allocation
+ *
+ * Takes an ion_fd_data struct with the handle field populated with a valid
+ * opaque handle.  Returns the struct with the fd field set to a file
+ * descriptor open in the current address space.  This file descriptor
+ * can then be passed to another process.  The corresponding opaque handle can
+ * be retrieved via ION_IOC_IMPORT.
+ */
+#define ION_IOC_SHARE		_IOWR(ION_IOC_MAGIC, 4, struct ion_fd_data)
+
+/**
+ * DOC: ION_IOC_IMPORT - imports a shared file descriptor
+ *
+ * Takes an ion_fd_data struct with the fd field populated with a valid file
+ * descriptor obtained from ION_IOC_SHARE and returns the struct with the handle
+ * filed set to the corresponding opaque handle.
+ */
+#define ION_IOC_IMPORT		_IOWR(ION_IOC_MAGIC, 5, struct ion_fd_data)
+
+/**
+ * DOC: ION_IOC_SYNC - syncs a shared file descriptors to memory
+ *
+ * Deprecated in favor of using the dma_buf api's correctly (syncing
+ * will happend automatically when the buffer is mapped to a device).
+ * If necessary should be used after touching a cached buffer from the cpu,
+ * this will make the buffer in memory coherent.
+ */
+#define ION_IOC_SYNC		_IOWR(ION_IOC_MAGIC, 7, struct ion_fd_data)
+
+/**
+ * DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl
+ *
+ * Takes the argument of the architecture specific ioctl to call and
+ * passes appropriate userdata for that ioctl
+ */
+#define ION_IOC_CUSTOM		_IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data)
+
+#endif /* _LINUX_ION_H */