ion_cma_heap.c revision f0ca3e87cc132b67c40ba1161cd02c8a2985ac4c 
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	if (buffer->flags & ION_FLAG_CACHED)
73		return -EINVAL;
74
75	if (align > PAGE_SIZE)
76		return -EINVAL;
77
78	info = kzalloc(sizeof(struct ion_cma_buffer_info), GFP_KERNEL);
79	if (!info)
80		return ION_CMA_ALLOCATE_FAILED;
81
82	info->cpu_addr = dma_alloc_coherent(dev, len, &(info->handle),
83						GFP_HIGHUSER | __GFP_ZERO);
84
85	if (!info->cpu_addr) {
86		dev_err(dev, "Fail to allocate buffer\n");
87		goto err;
88	}
89
90	info->table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
91	if (!info->table)
92		goto free_mem;
93
94	if (ion_cma_get_sgtable
95	    (dev, info->table, info->cpu_addr, info->handle, len))
96		goto free_table;
97	/* keep this for memory release */
98	buffer->priv_virt = info;
99	dev_dbg(dev, "Allocate buffer %p\n", buffer);
100	return 0;
101
102free_table:
103	kfree(info->table);
104free_mem:
105	dma_free_coherent(dev, len, info->cpu_addr, info->handle);
106err:
107	kfree(info);
108	return ION_CMA_ALLOCATE_FAILED;
109}
110
111static void ion_cma_free(struct ion_buffer *buffer)
112{
113	struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
114	struct device *dev = cma_heap->dev;
115	struct ion_cma_buffer_info *info = buffer->priv_virt;
116
117	dev_dbg(dev, "Release buffer %p\n", buffer);
118	/* release memory */
119	dma_free_coherent(dev, buffer->size, info->cpu_addr, info->handle);
120	/* release sg table */
121	sg_free_table(info->table);
122	kfree(info->table);
123	kfree(info);
124}
125
126/* return physical address in addr */
127static int ion_cma_phys(struct ion_heap *heap, struct ion_buffer *buffer,
128			ion_phys_addr_t *addr, size_t *len)
129{
130	struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
131	struct device *dev = cma_heap->dev;
132	struct ion_cma_buffer_info *info = buffer->priv_virt;
133
134	dev_dbg(dev, "Return buffer %p physical address %pa\n", buffer,
135		&info->handle);
136
137	*addr = info->handle;
138	*len = buffer->size;
139
140	return 0;
141}
142
143static struct sg_table *ion_cma_heap_map_dma(struct ion_heap *heap,
144					     struct ion_buffer *buffer)
145{
146	struct ion_cma_buffer_info *info = buffer->priv_virt;
147
148	return info->table;
149}
150
151static void ion_cma_heap_unmap_dma(struct ion_heap *heap,
152				   struct ion_buffer *buffer)
153{
154}
155
156static int ion_cma_mmap(struct ion_heap *mapper, struct ion_buffer *buffer,
157			struct vm_area_struct *vma)
158{
159	struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
160	struct device *dev = cma_heap->dev;
161	struct ion_cma_buffer_info *info = buffer->priv_virt;
162
163	return dma_mmap_coherent(dev, vma, info->cpu_addr, info->handle,
164				 buffer->size);
165}
166
167static void *ion_cma_map_kernel(struct ion_heap *heap,
168				struct ion_buffer *buffer)
169{
170	struct ion_cma_buffer_info *info = buffer->priv_virt;
171	/* kernel memory mapping has been done at allocation time */
172	return info->cpu_addr;
173}
174
175static void ion_cma_unmap_kernel(struct ion_heap *heap,
176					struct ion_buffer *buffer)
177{
178}
179
180static struct ion_heap_ops ion_cma_ops = {
181	.allocate = ion_cma_allocate,
182	.free = ion_cma_free,
183	.map_dma = ion_cma_heap_map_dma,
184	.unmap_dma = ion_cma_heap_unmap_dma,
185	.phys = ion_cma_phys,
186	.map_user = ion_cma_mmap,
187	.map_kernel = ion_cma_map_kernel,
188	.unmap_kernel = ion_cma_unmap_kernel,
189};
190
191struct ion_heap *ion_cma_heap_create(struct ion_platform_heap *data)
192{
193	struct ion_cma_heap *cma_heap;
194
195	cma_heap = kzalloc(sizeof(struct ion_cma_heap), GFP_KERNEL);
196
197	if (!cma_heap)
198		return ERR_PTR(-ENOMEM);
199
200	cma_heap->heap.ops = &ion_cma_ops;
201	/* get device from private heaps data, later it will be
202	 * used to make the link with reserved CMA memory */
203	cma_heap->dev = data->priv;
204	cma_heap->heap.type = ION_HEAP_TYPE_DMA;
205	return &cma_heap->heap;
206}
207
208void ion_cma_heap_destroy(struct ion_heap *heap)
209{
210	struct ion_cma_heap *cma_heap = to_cma_heap(heap);
211
212	kfree(cma_heap);
213}
214