ion_chunk_heap.c revision b6152016003b2cc2370899558bf2e7de4ebd0b09 
1/*
2 * drivers/staging/android/ion/ion_chunk_heap.c
3 *
4 * Copyright (C) 2012 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#include <linux/dma-mapping.h>
17#include <linux/err.h>
18#include <linux/genalloc.h>
19#include <linux/io.h>
20#include <linux/mm.h>
21#include <linux/scatterlist.h>
22#include <linux/slab.h>
23#include <linux/vmalloc.h>
24#include "ion.h"
25#include "ion_priv.h"
26
27struct ion_chunk_heap {
28	struct ion_heap heap;
29	struct gen_pool *pool;
30	ion_phys_addr_t base;
31	unsigned long chunk_size;
32	unsigned long size;
33	unsigned long allocated;
34};
35
36static int ion_chunk_heap_allocate(struct ion_heap *heap,
37				      struct ion_buffer *buffer,
38				      unsigned long size, unsigned long align,
39				      unsigned long flags)
40{
41	struct ion_chunk_heap *chunk_heap =
42		container_of(heap, struct ion_chunk_heap, heap);
43	struct sg_table *table;
44	struct scatterlist *sg;
45	int ret, i;
46	unsigned long num_chunks;
47	unsigned long allocated_size;
48
49	if (align > chunk_heap->chunk_size)
50		return -EINVAL;
51
52	allocated_size = ALIGN(size, chunk_heap->chunk_size);
53	num_chunks = allocated_size / chunk_heap->chunk_size;
54
55	if (allocated_size > chunk_heap->size - chunk_heap->allocated)
56		return -ENOMEM;
57
58	table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
59	if (!table)
60		return -ENOMEM;
61	ret = sg_alloc_table(table, num_chunks, GFP_KERNEL);
62	if (ret) {
63		kfree(table);
64		return ret;
65	}
66
67	sg = table->sgl;
68	for (i = 0; i < num_chunks; i++) {
69		unsigned long paddr = gen_pool_alloc(chunk_heap->pool,
70						     chunk_heap->chunk_size);
71		if (!paddr)
72			goto err;
73		sg_set_page(sg, pfn_to_page(PFN_DOWN(paddr)),
74				chunk_heap->chunk_size, 0);
75		sg = sg_next(sg);
76	}
77
78	buffer->priv_virt = table;
79	chunk_heap->allocated += allocated_size;
80	return 0;
81err:
82	sg = table->sgl;
83	for (i -= 1; i >= 0; i--) {
84		gen_pool_free(chunk_heap->pool, page_to_phys(sg_page(sg)),
85			      sg->length);
86		sg = sg_next(sg);
87	}
88	sg_free_table(table);
89	kfree(table);
90	return -ENOMEM;
91}
92
93static void ion_chunk_heap_free(struct ion_buffer *buffer)
94{
95	struct ion_heap *heap = buffer->heap;
96	struct ion_chunk_heap *chunk_heap =
97		container_of(heap, struct ion_chunk_heap, heap);
98	struct sg_table *table = buffer->priv_virt;
99	struct scatterlist *sg;
100	int i;
101	unsigned long allocated_size;
102
103	allocated_size = ALIGN(buffer->size, chunk_heap->chunk_size);
104
105	ion_heap_buffer_zero(buffer);
106
107	if (ion_buffer_cached(buffer))
108		dma_sync_sg_for_device(NULL, table->sgl, table->nents,
109								DMA_BIDIRECTIONAL);
110
111	for_each_sg(table->sgl, sg, table->nents, i) {
112		gen_pool_free(chunk_heap->pool, page_to_phys(sg_page(sg)),
113			      sg->length);
114	}
115	chunk_heap->allocated -= allocated_size;
116	sg_free_table(table);
117	kfree(table);
118}
119
120static struct sg_table *ion_chunk_heap_map_dma(struct ion_heap *heap,
121					       struct ion_buffer *buffer)
122{
123	return buffer->priv_virt;
124}
125
126static void ion_chunk_heap_unmap_dma(struct ion_heap *heap,
127				     struct ion_buffer *buffer)
128{
129	return;
130}
131
132static struct ion_heap_ops chunk_heap_ops = {
133	.allocate = ion_chunk_heap_allocate,
134	.free = ion_chunk_heap_free,
135	.map_dma = ion_chunk_heap_map_dma,
136	.unmap_dma = ion_chunk_heap_unmap_dma,
137	.map_user = ion_heap_map_user,
138	.map_kernel = ion_heap_map_kernel,
139	.unmap_kernel = ion_heap_unmap_kernel,
140};
141
142struct ion_heap *ion_chunk_heap_create(struct ion_platform_heap *heap_data)
143{
144	struct ion_chunk_heap *chunk_heap;
145	int ret;
146	struct page *page;
147	size_t size;
148
149	page = pfn_to_page(PFN_DOWN(heap_data->base));
150	size = heap_data->size;
151
152	ion_pages_sync_for_device(NULL, page, size, DMA_BIDIRECTIONAL);
153
154	ret = ion_heap_pages_zero(page, size, pgprot_writecombine(PAGE_KERNEL));
155	if (ret)
156		return ERR_PTR(ret);
157
158	chunk_heap = kzalloc(sizeof(struct ion_chunk_heap), GFP_KERNEL);
159	if (!chunk_heap)
160		return ERR_PTR(-ENOMEM);
161
162	chunk_heap->chunk_size = (unsigned long)heap_data->priv;
163	chunk_heap->pool = gen_pool_create(get_order(chunk_heap->chunk_size) +
164					   PAGE_SHIFT, -1);
165	if (!chunk_heap->pool) {
166		ret = -ENOMEM;
167		goto error_gen_pool_create;
168	}
169	chunk_heap->base = heap_data->base;
170	chunk_heap->size = heap_data->size;
171	chunk_heap->allocated = 0;
172
173	gen_pool_add(chunk_heap->pool, chunk_heap->base, heap_data->size, -1);
174	chunk_heap->heap.ops = &chunk_heap_ops;
175	chunk_heap->heap.type = ION_HEAP_TYPE_CHUNK;
176	chunk_heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
177	pr_info("%s: base %lu size %zu align %ld\n", __func__, chunk_heap->base,
178		heap_data->size, heap_data->align);
179
180	return &chunk_heap->heap;
181
182error_gen_pool_create:
183	kfree(chunk_heap);
184	return ERR_PTR(ret);
185}
186
187void ion_chunk_heap_destroy(struct ion_heap *heap)
188{
189	struct ion_chunk_heap *chunk_heap =
190	     container_of(heap, struct  ion_chunk_heap, heap);
191
192	gen_pool_destroy(chunk_heap->pool);
193	kfree(chunk_heap);
194	chunk_heap = NULL;
195}
196