ion_cma_heap.c revision f63958d80c07c04db48812d97ff7450517d80ffa 
1/*
2 * drivers/staging/android/ion/ion_cma_heap.c
3 *
4 * Copyright (C) Linaro 2012
5 * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
6 *
7 * This software is licensed under the terms of the GNU General Public
8 * License version 2, as published by the Free Software Foundation, and
9 * may be copied, distributed, and modified under those terms.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 */
17
18#include <linux/device.h>
19#include <linux/slab.h>
20#include <linux/errno.h>
21#include <linux/err.h>
22#include <linux/dma-mapping.h>
23
24#include "ion.h"
25#include "ion_priv.h"
26
27#define ION_CMA_ALLOCATE_FAILED -1
28
29struct ion_cma_heap {
30	struct ion_heap heap;
31	struct device *dev;
32};
33
34#define to_cma_heap(x) container_of(x, struct ion_cma_heap, heap)
35
36struct ion_cma_buffer_info {
37	void *cpu_addr;
38	dma_addr_t handle;
39	struct sg_table *table;
40};
41
42/*
43 * Create scatter-list for the already allocated DMA buffer.
44 * This function could be replaced by dma_common_get_sgtable
45 * as soon as it will avalaible.
46 */
47static int ion_cma_get_sgtable(struct device *dev, struct sg_table *sgt,
48			       void *cpu_addr, dma_addr_t handle, size_t size)
49{
50	struct page *page = virt_to_page(cpu_addr);
51	int ret;
52
53	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
54	if (unlikely(ret))
55		return ret;
56
57	sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
58	return 0;
59}
60
61/* ION CMA heap operations functions */
62static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
63			    unsigned long len, unsigned long align,
64			    unsigned long flags)
65{
66	struct ion_cma_heap *cma_heap = to_cma_heap(heap);
67	struct device *dev = cma_heap->dev;
68	struct ion_cma_buffer_info *info;
69
70	dev_dbg(dev, "Request buffer allocation len %ld\n", len);
71
72	info = kzalloc(sizeof(struct ion_cma_buffer_info), GFP_KERNEL);
73	if (!info) {
74		dev_err(dev, "Can't allocate buffer info\n");
75		return ION_CMA_ALLOCATE_FAILED;
76	}
77
78	info->cpu_addr = dma_alloc_coherent(dev, len, &(info->handle), 0);
79
80	if (!info->cpu_addr) {
81		dev_err(dev, "Fail to allocate buffer\n");
82		goto err;
83	}
84
85	info->table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
86	if (!info->table) {
87		dev_err(dev, "Fail to allocate sg table\n");
88		goto free_mem;
89	}
90
91	if (ion_cma_get_sgtable
92	    (dev, info->table, info->cpu_addr, info->handle, len))
93		goto free_table;
94	/* keep this for memory release */
95	buffer->priv_virt = info;
96	dev_dbg(dev, "Allocate buffer %p\n", buffer);
97	return 0;
98
99free_table:
100	kfree(info->table);
101free_mem:
102	dma_free_coherent(dev, len, info->cpu_addr, info->handle);
103err:
104	kfree(info);
105	return ION_CMA_ALLOCATE_FAILED;
106}
107
108static void ion_cma_free(struct ion_buffer *buffer)
109{
110	struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
111	struct device *dev = cma_heap->dev;
112	struct ion_cma_buffer_info *info = buffer->priv_virt;
113
114	dev_dbg(dev, "Release buffer %p\n", buffer);
115	/* release memory */
116	dma_free_coherent(dev, buffer->size, info->cpu_addr, info->handle);
117	/* release sg table */
118	sg_free_table(info->table);
119	kfree(info->table);
120	kfree(info);
121}
122
123/* return physical address in addr */
124static int ion_cma_phys(struct ion_heap *heap, struct ion_buffer *buffer,
125			ion_phys_addr_t *addr, size_t *len)
126{
127	struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
128	struct device *dev = cma_heap->dev;
129	struct ion_cma_buffer_info *info = buffer->priv_virt;
130
131	dev_dbg(dev, "Return buffer %p physical address 0x%pa\n", buffer,
132		&info->handle);
133
134	*addr = info->handle;
135	*len = buffer->size;
136
137	return 0;
138}
139
140static struct sg_table *ion_cma_heap_map_dma(struct ion_heap *heap,
141					     struct ion_buffer *buffer)
142{
143	struct ion_cma_buffer_info *info = buffer->priv_virt;
144
145	return info->table;
146}
147
148static void ion_cma_heap_unmap_dma(struct ion_heap *heap,
149				   struct ion_buffer *buffer)
150{
151	return;
152}
153
154static int ion_cma_mmap(struct ion_heap *mapper, struct ion_buffer *buffer,
155			struct vm_area_struct *vma)
156{
157	struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
158	struct device *dev = cma_heap->dev;
159	struct ion_cma_buffer_info *info = buffer->priv_virt;
160
161	return dma_mmap_coherent(dev, vma, info->cpu_addr, info->handle,
162				 buffer->size);
163}
164
165static void *ion_cma_map_kernel(struct ion_heap *heap,
166				struct ion_buffer *buffer)
167{
168	struct ion_cma_buffer_info *info = buffer->priv_virt;
169	/* kernel memory mapping has been done at allocation time */
170	return info->cpu_addr;
171}
172
173static struct ion_heap_ops ion_cma_ops = {
174	.allocate = ion_cma_allocate,
175	.free = ion_cma_free,
176	.map_dma = ion_cma_heap_map_dma,
177	.unmap_dma = ion_cma_heap_unmap_dma,
178	.phys = ion_cma_phys,
179	.map_user = ion_cma_mmap,
180	.map_kernel = ion_cma_map_kernel,
181};
182
183struct ion_heap *ion_cma_heap_create(struct ion_platform_heap *data)
184{
185	struct ion_cma_heap *cma_heap;
186
187	cma_heap = kzalloc(sizeof(struct ion_cma_heap), GFP_KERNEL);
188
189	if (!cma_heap)
190		return ERR_PTR(-ENOMEM);
191
192	cma_heap->heap.ops = &ion_cma_ops;
193	/* get device from private heaps data, later it will be
194	 * used to make the link with reserved CMA memory */
195	cma_heap->dev = data->priv;
196	cma_heap->heap.type = ION_HEAP_TYPE_DMA;
197	return &cma_heap->heap;
198}
199
200void ion_cma_heap_destroy(struct ion_heap *heap)
201{
202	struct ion_cma_heap *cma_heap = to_cma_heap(heap);
203
204	kfree(cma_heap);
205}
206