[thirdparty/kernel/linux.git] / drivers / staging / android / ion / ion_system_heap.c

/*
 * drivers/staging/android/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/mm.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include "ion.h"
#include "ion_priv.h"

struct page_info {
	struct page *page;
	unsigned long order;
	struct list_head list;
};

static unsigned int orders[] = {8, 4, 0};

static struct page_info *alloc_largest_available(unsigned long size,
						 bool split_pages,
						 unsigned int max_order)
{
	struct page *page;
	struct page_info *info;
	int i;

	for (i = 0; i < ARRAY_SIZE(orders); i++) {
		if (size < (1 << orders[i]) * PAGE_SIZE)
			continue;
		if (max_order < orders[i])
			continue;
		page = alloc_pages(GFP_HIGHUSER | __GFP_ZERO |
				   __GFP_NOWARN | __GFP_NORETRY, orders[i]);
		if (!page)
			continue;
		if (split_pages)
			split_page(page, orders[i]);
		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 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);
	bool split_pages = ion_buffer_fault_user_mappings(buffer);


	unsigned int max_order = orders[0];

	INIT_LIST_HEAD(&pages);
	while (size_remaining > 0) {
		info = alloc_largest_available(size_remaining, split_pages,
					       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);
	}

	dma_sync_sg_for_device(NULL, table->sgl, table->nents,
			       DMA_BIDIRECTIONAL);

	buffer->priv_virt = table;
	return 0;
err1:
	kfree(table);
err:
	list_for_each_entry(info, &pages, list) {
		if (split_pages)
			for (i = 0; i < (1 << info->order); i++)
				__free_page(info->page + i);
		else
			__free_pages(info->page, info->order);

		kfree(info);
	}
	return -ENOMEM;
}

void ion_system_heap_free(struct ion_buffer *buffer)
{
	int i;
	struct scatterlist *sg;
	struct sg_table *table = buffer->priv_virt;

	for_each_sg(table->sgl, sg, table->nents, i)
		__free_pages(sg_page(sg), get_order(sg_dma_len(sg)));
	if (buffer->sg_table)
		sg_free_table(buffer->sg_table);
	kfree(buffer->sg_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;
}

void *ion_system_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->priv_virt;
	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_system_heap_unmap_kernel(struct ion_heap *heap,
				  struct ion_buffer *buffer)
{
	vunmap(buffer->vaddr);
}

int ion_system_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
			     struct vm_area_struct *vma)
{
	struct sg_table *table = buffer->priv_virt;
	unsigned long addr = vma->vm_start;
	unsigned long offset = vma->vm_pgoff;
	struct scatterlist *sg;
	int i;

	for_each_sg(table->sgl, sg, table->nents, i) {
		if (offset) {
			offset--;
			continue;
		}
		remap_pfn_range(vma, addr, page_to_pfn(sg_page(sg)),
				sg_dma_len(sg), vma->vm_page_prot);
		addr += sg_dma_len(sg);
		if (addr >= vma->vm_end)
			return 0;
	}
	return 0;
}

static struct ion_heap_ops vmalloc_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_system_heap_map_kernel,
	.unmap_kernel = ion_system_heap_unmap_kernel,
	.map_user = ion_system_heap_map_user,
};

struct ion_heap *ion_system_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 = &vmalloc_ops;
	heap->type = ION_HEAP_TYPE_SYSTEM;
	return heap;
}

void ion_system_heap_destroy(struct ion_heap *heap)
{
	kfree(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_system_heap_map_kernel,
	.unmap_kernel = ion_system_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);
}
Commit	Line	Data
c30707be RSZ	1	/*
	2	* drivers/staging/android/ion/ion_system_heap.c
	3	*
	4	* Copyright (C) 2011 Google, Inc.
	5	*
	6	* This software is licensed under the terms of the GNU General Public
	7	* License version 2, as published by the Free Software Foundation, and
	8	* may be copied, distributed, and modified under those terms.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	*/
	16
bd5d6bda RSZ	17	#include <asm/page.h>
bd5d6bda RSZ	18	#include <linux/dma-mapping.h>
c30707be	19	#include <linux/err.h>
bd5d6bda	20	#include <linux/highmem.h>
c30707be RSZ	21	#include <linux/mm.h>
	22	#include <linux/scatterlist.h>
	23	#include <linux/slab.h>
	24	#include <linux/vmalloc.h>
	25	#include "ion.h"
	26	#include "ion_priv.h"
	27
bd5d6bda RSZ	28	struct page_info {
	29	struct page *page;
	30	unsigned long order;
	31	struct list_head list;
	32	};
	33
b0599c01 RSZ	34	static unsigned int orders[] = {8, 4, 0};
b0599c01 RSZ	35
13ba7805	36	static struct page_info *alloc_largest_available(unsigned long size,
ba96a2ee RSZ	37	bool split_pages,
ba96a2ee RSZ	38	unsigned int max_order)
bd5d6bda	39	{
bd5d6bda RSZ	40	struct page *page;
	41	struct page_info *info;
	42	int i;
	43
	44	for (i = 0; i < ARRAY_SIZE(orders); i++) {
	45	if (size < (1 << orders[i]) * PAGE_SIZE)
	46	continue;
ba96a2ee RSZ	47	if (max_order < orders[i])
ba96a2ee RSZ	48	continue;
fe65ec5b	49	page = alloc_pages(GFP_HIGHUSER \| __GFP_ZERO \|
bd5d6bda RSZ	50	__GFP_NOWARN \| __GFP_NORETRY, orders[i]);
	51	if (!page)
	52	continue;
13ba7805 RSZ	53	if (split_pages)
13ba7805 RSZ	54	split_page(page, orders[i]);
708f0cac	55	info = kmalloc(sizeof(struct page_info *), GFP_KERNEL);
bd5d6bda RSZ	56	info->page = page;
	57	info->order = orders[i];
	58	return info;
	59	}
	60	return NULL;
	61	}
	62
c30707be RSZ	63	static int ion_system_heap_allocate(struct ion_heap *heap,
	64	struct ion_buffer *buffer,
	65	unsigned long size, unsigned long align,
	66	unsigned long flags)
c30707be	67	{
4d5ca329 RSZ	68	struct sg_table *table;
4d5ca329 RSZ	69	struct scatterlist *sg;
bd5d6bda RSZ	70	int ret;
	71	struct list_head pages;
	72	struct page_info info, tmp_info;
13ba7805	73	int i = 0;
bd5d6bda	74	long size_remaining = PAGE_ALIGN(size);
13ba7805 RSZ	75	bool split_pages = ion_buffer_fault_user_mappings(buffer);
13ba7805 RSZ	76
bd5d6bda	77
ba96a2ee RSZ	78	unsigned int max_order = orders[0];
ba96a2ee RSZ	79
bd5d6bda RSZ	80	INIT_LIST_HEAD(&pages);
bd5d6bda RSZ	81	while (size_remaining > 0) {
ba96a2ee RSZ	82	info = alloc_largest_available(size_remaining, split_pages,
ba96a2ee RSZ	83	max_order);
bd5d6bda RSZ	84	if (!info)
	85	goto err;
	86	list_add_tail(&info->list, &pages);
	87	size_remaining -= (1 << info->order) * PAGE_SIZE;
ba96a2ee	88	max_order = info->order;
13ba7805	89	i++;
bd5d6bda	90	}
c30707be	91
b15934b6	92	table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
4d5ca329	93	if (!table)
bd5d6bda RSZ	94	goto err;
bd5d6bda RSZ	95
13ba7805 RSZ	96	if (split_pages)
	97	ret = sg_alloc_table(table, PAGE_ALIGN(size) / PAGE_SIZE,
	98	GFP_KERNEL);
	99	else
	100	ret = sg_alloc_table(table, i, GFP_KERNEL);
	101
bd5d6bda RSZ	102	if (ret)
	103	goto err1;
	104
	105	sg = table->sgl;
	106	list_for_each_entry_safe(info, tmp_info, &pages, list) {
	107	struct page *page = info->page;
13ba7805 RSZ	108
	109	if (split_pages) {
	110	for (i = 0; i < (1 << info->order); i++) {
	111	sg_set_page(sg, page + i, PAGE_SIZE, 0);
	112	sg = sg_next(sg);
	113	}
	114	} else {
	115	sg_set_page(sg, page, (1 << info->order) * PAGE_SIZE,
	116	0);
bd5d6bda RSZ	117	sg = sg_next(sg);
	118	}
	119	list_del(&info->list);
708f0cac	120	kfree(info);
c30707be	121	}
bd5d6bda RSZ	122
	123	dma_sync_sg_for_device(NULL, table->sgl, table->nents,
	124	DMA_BIDIRECTIONAL);
	125
b15934b6 RSZ	126	buffer->priv_virt = table;
b15934b6 RSZ	127	return 0;
4d5ca329	128	err1:
4d5ca329	129	kfree(table);
bd5d6bda RSZ	130	err:
bd5d6bda RSZ	131	list_for_each_entry(info, &pages, list) {
13ba7805 RSZ	132	if (split_pages)
	133	for (i = 0; i < (1 << info->order); i++)
	134	__free_page(info->page + i);
	135	else
	136	__free_pages(info->page, info->order);
	137
708f0cac	138	kfree(info);
bd5d6bda	139	}
b15934b6	140	return -ENOMEM;
c30707be RSZ	141	}
c30707be RSZ	142
b15934b6	143	void ion_system_heap_free(struct ion_buffer *buffer)
c30707be	144	{
b15934b6 RSZ	145	int i;
	146	struct scatterlist *sg;
	147	struct sg_table *table = buffer->priv_virt;
	148
	149	for_each_sg(table->sgl, sg, table->nents, i)
bd5d6bda	150	__free_pages(sg_page(sg), get_order(sg_dma_len(sg)));
4d5ca329 RSZ	151	if (buffer->sg_table)
	152	sg_free_table(buffer->sg_table);
	153	kfree(buffer->sg_table);
c30707be RSZ	154	}
c30707be RSZ	155
b15934b6 RSZ	156	struct sg_table ion_system_heap_map_dma(struct ion_heap heap,
	157	struct ion_buffer *buffer)
	158	{
	159	return buffer->priv_virt;
	160	}
	161
	162	void ion_system_heap_unmap_dma(struct ion_heap *heap,
	163	struct ion_buffer *buffer)
	164	{
	165	return;
	166	}
	167
c30707be RSZ	168	void ion_system_heap_map_kernel(struct ion_heap heap,
	169	struct ion_buffer *buffer)
	170	{
b15934b6	171	struct scatterlist *sg;
bd5d6bda	172	int i, j;
b15934b6	173	void *vaddr;
56a7c185	174	pgprot_t pgprot;
b15934b6	175	struct sg_table *table = buffer->priv_virt;
bd5d6bda	176	int npages = PAGE_ALIGN(buffer->size) / PAGE_SIZE;
98d5d5f8	177	struct page *pages = vmalloc(sizeof(struct page ) * npages);
bd5d6bda	178	struct page **tmp = pages;
56a7c185	179
98d5d5f8 RSZ	180	if (!pages)
	181	return 0;
	182
56a7c185 RSZ	183	if (buffer->flags & ION_FLAG_CACHED)
	184	pgprot = PAGE_KERNEL;
	185	else
	186	pgprot = pgprot_writecombine(PAGE_KERNEL);
	187
bd5d6bda RSZ	188	for_each_sg(table->sgl, sg, table->nents, i) {
	189	int npages_this_entry = PAGE_ALIGN(sg_dma_len(sg)) / PAGE_SIZE;
	190	struct page *page = sg_page(sg);
	191	BUG_ON(i >= npages);
	192	for (j = 0; j < npages_this_entry; j++) {
	193	*(tmp++) = page++;
	194	}
	195	}
	196	vaddr = vmap(pages, npages, VM_MAP, pgprot);
98d5d5f8	197	vfree(pages);
b15934b6 RSZ	198
b15934b6 RSZ	199	return vaddr;
c30707be RSZ	200	}
	201
	202	void ion_system_heap_unmap_kernel(struct ion_heap *heap,
	203	struct ion_buffer *buffer)
	204	{
b15934b6	205	vunmap(buffer->vaddr);
c30707be RSZ	206	}
	207
	208	int ion_system_heap_map_user(struct ion_heap heap, struct ion_buffer buffer,
	209	struct vm_area_struct *vma)
	210	{
b15934b6 RSZ	211	struct sg_table *table = buffer->priv_virt;
	212	unsigned long addr = vma->vm_start;
	213	unsigned long offset = vma->vm_pgoff;
	214	struct scatterlist *sg;
	215	int i;
	216
	217	for_each_sg(table->sgl, sg, table->nents, i) {
	218	if (offset) {
	219	offset--;
	220	continue;
	221	}
bd5d6bda RSZ	222	remap_pfn_range(vma, addr, page_to_pfn(sg_page(sg)),
	223	sg_dma_len(sg), vma->vm_page_prot);
	224	addr += sg_dma_len(sg);
b8230243 RSZ	225	if (addr >= vma->vm_end)
b8230243 RSZ	226	return 0;
b15934b6 RSZ	227	}
b15934b6 RSZ	228	return 0;
c30707be RSZ	229	}
	230
	231	static struct ion_heap_ops vmalloc_ops = {
	232	.allocate = ion_system_heap_allocate,
	233	.free = ion_system_heap_free,
	234	.map_dma = ion_system_heap_map_dma,
	235	.unmap_dma = ion_system_heap_unmap_dma,
	236	.map_kernel = ion_system_heap_map_kernel,
	237	.unmap_kernel = ion_system_heap_unmap_kernel,
	238	.map_user = ion_system_heap_map_user,
	239	};
	240
	241	struct ion_heap ion_system_heap_create(struct ion_platform_heap unused)
	242	{
	243	struct ion_heap *heap;
	244
	245	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
	246	if (!heap)
	247	return ERR_PTR(-ENOMEM);
	248	heap->ops = &vmalloc_ops;
	249	heap->type = ION_HEAP_TYPE_SYSTEM;
	250	return heap;
	251	}
	252
	253	void ion_system_heap_destroy(struct ion_heap *heap)
	254	{
	255	kfree(heap);
	256	}
	257
	258	static int ion_system_contig_heap_allocate(struct ion_heap *heap,
	259	struct ion_buffer *buffer,
	260	unsigned long len,
	261	unsigned long align,
	262	unsigned long flags)
	263	{
	264	buffer->priv_virt = kzalloc(len, GFP_KERNEL);
	265	if (!buffer->priv_virt)
	266	return -ENOMEM;
	267	return 0;
	268	}
	269
	270	void ion_system_contig_heap_free(struct ion_buffer *buffer)
	271	{
	272	kfree(buffer->priv_virt);
	273	}
	274
	275	static int ion_system_contig_heap_phys(struct ion_heap *heap,
	276	struct ion_buffer *buffer,
	277	ion_phys_addr_t addr, size_t len)
	278	{
	279	*addr = virt_to_phys(buffer->priv_virt);
	280	*len = buffer->size;
	281	return 0;
	282	}
	283
4d5ca329	284	struct sg_table ion_system_contig_heap_map_dma(struct ion_heap heap,
56a7c185	285	struct ion_buffer *buffer)
c30707be	286	{
4d5ca329 RSZ	287	struct sg_table *table;
4d5ca329 RSZ	288	int ret;
c30707be	289
4d5ca329 RSZ	290	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
4d5ca329 RSZ	291	if (!table)
c30707be	292	return ERR_PTR(-ENOMEM);
4d5ca329 RSZ	293	ret = sg_alloc_table(table, 1, GFP_KERNEL);
	294	if (ret) {
	295	kfree(table);
	296	return ERR_PTR(ret);
	297	}
	298	sg_set_page(table->sgl, virt_to_page(buffer->priv_virt), buffer->size,
	299	0);
	300	return table;
c30707be RSZ	301	}
c30707be RSZ	302
56a7c185 RSZ	303	void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
	304	struct ion_buffer *buffer)
	305	{
	306	sg_free_table(buffer->sg_table);
	307	kfree(buffer->sg_table);
	308	}
	309
c30707be RSZ	310	int ion_system_contig_heap_map_user(struct ion_heap *heap,
	311	struct ion_buffer *buffer,
	312	struct vm_area_struct *vma)
	313	{
	314	unsigned long pfn = __phys_to_pfn(virt_to_phys(buffer->priv_virt));
	315	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
	316	vma->vm_end - vma->vm_start,
	317	vma->vm_page_prot);
	318
	319	}
	320
	321	static struct ion_heap_ops kmalloc_ops = {
	322	.allocate = ion_system_contig_heap_allocate,
	323	.free = ion_system_contig_heap_free,
	324	.phys = ion_system_contig_heap_phys,
	325	.map_dma = ion_system_contig_heap_map_dma,
56a7c185	326	.unmap_dma = ion_system_contig_heap_unmap_dma,
c30707be RSZ	327	.map_kernel = ion_system_heap_map_kernel,
	328	.unmap_kernel = ion_system_heap_unmap_kernel,
	329	.map_user = ion_system_contig_heap_map_user,
	330	};
	331
	332	struct ion_heap ion_system_contig_heap_create(struct ion_platform_heap unused)
	333	{
	334	struct ion_heap *heap;
	335
	336	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
	337	if (!heap)
	338	return ERR_PTR(-ENOMEM);
	339	heap->ops = &kmalloc_ops;
	340	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
	341	return heap;
	342	}
	343
	344	void ion_system_contig_heap_destroy(struct ion_heap *heap)
	345	{
	346	kfree(heap);
	347	}
	348