Root/drivers/base/dma-mapping.c

1/*
2 * drivers/base/dma-mapping.c - arch-independent dma-mapping routines
3 *
4 * Copyright (c) 2006 SUSE Linux Products GmbH
5 * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
6 *
7 * This file is released under the GPLv2.
8 */
9
10#include <linux/dma-mapping.h>
11#include <linux/export.h>
12#include <linux/gfp.h>
13#include <asm-generic/dma-coherent.h>
14
15/*
16 * Managed DMA API
17 */
18struct dma_devres {
19    size_t size;
20    void *vaddr;
21    dma_addr_t dma_handle;
22};
23
24static void dmam_coherent_release(struct device *dev, void *res)
25{
26    struct dma_devres *this = res;
27
28    dma_free_coherent(dev, this->size, this->vaddr, this->dma_handle);
29}
30
31static void dmam_noncoherent_release(struct device *dev, void *res)
32{
33    struct dma_devres *this = res;
34
35    dma_free_noncoherent(dev, this->size, this->vaddr, this->dma_handle);
36}
37
38static int dmam_match(struct device *dev, void *res, void *match_data)
39{
40    struct dma_devres *this = res, *match = match_data;
41
42    if (this->vaddr == match->vaddr) {
43        WARN_ON(this->size != match->size ||
44            this->dma_handle != match->dma_handle);
45        return 1;
46    }
47    return 0;
48}
49
50/**
51 * dmam_alloc_coherent - Managed dma_alloc_coherent()
52 * @dev: Device to allocate coherent memory for
53 * @size: Size of allocation
54 * @dma_handle: Out argument for allocated DMA handle
55 * @gfp: Allocation flags
56 *
57 * Managed dma_alloc_coherent(). Memory allocated using this function
58 * will be automatically released on driver detach.
59 *
60 * RETURNS:
61 * Pointer to allocated memory on success, NULL on failure.
62 */
63void * dmam_alloc_coherent(struct device *dev, size_t size,
64               dma_addr_t *dma_handle, gfp_t gfp)
65{
66    struct dma_devres *dr;
67    void *vaddr;
68
69    dr = devres_alloc(dmam_coherent_release, sizeof(*dr), gfp);
70    if (!dr)
71        return NULL;
72
73    vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
74    if (!vaddr) {
75        devres_free(dr);
76        return NULL;
77    }
78
79    dr->vaddr = vaddr;
80    dr->dma_handle = *dma_handle;
81    dr->size = size;
82
83    devres_add(dev, dr);
84
85    return vaddr;
86}
87EXPORT_SYMBOL(dmam_alloc_coherent);
88
89/**
90 * dmam_free_coherent - Managed dma_free_coherent()
91 * @dev: Device to free coherent memory for
92 * @size: Size of allocation
93 * @vaddr: Virtual address of the memory to free
94 * @dma_handle: DMA handle of the memory to free
95 *
96 * Managed dma_free_coherent().
97 */
98void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
99            dma_addr_t dma_handle)
100{
101    struct dma_devres match_data = { size, vaddr, dma_handle };
102
103    dma_free_coherent(dev, size, vaddr, dma_handle);
104    WARN_ON(devres_destroy(dev, dmam_coherent_release, dmam_match,
105                   &match_data));
106}
107EXPORT_SYMBOL(dmam_free_coherent);
108
109/**
110 * dmam_alloc_non_coherent - Managed dma_alloc_non_coherent()
111 * @dev: Device to allocate non_coherent memory for
112 * @size: Size of allocation
113 * @dma_handle: Out argument for allocated DMA handle
114 * @gfp: Allocation flags
115 *
116 * Managed dma_alloc_non_coherent(). Memory allocated using this
117 * function will be automatically released on driver detach.
118 *
119 * RETURNS:
120 * Pointer to allocated memory on success, NULL on failure.
121 */
122void *dmam_alloc_noncoherent(struct device *dev, size_t size,
123                 dma_addr_t *dma_handle, gfp_t gfp)
124{
125    struct dma_devres *dr;
126    void *vaddr;
127
128    dr = devres_alloc(dmam_noncoherent_release, sizeof(*dr), gfp);
129    if (!dr)
130        return NULL;
131
132    vaddr = dma_alloc_noncoherent(dev, size, dma_handle, gfp);
133    if (!vaddr) {
134        devres_free(dr);
135        return NULL;
136    }
137
138    dr->vaddr = vaddr;
139    dr->dma_handle = *dma_handle;
140    dr->size = size;
141
142    devres_add(dev, dr);
143
144    return vaddr;
145}
146EXPORT_SYMBOL(dmam_alloc_noncoherent);
147
148/**
149 * dmam_free_coherent - Managed dma_free_noncoherent()
150 * @dev: Device to free noncoherent memory for
151 * @size: Size of allocation
152 * @vaddr: Virtual address of the memory to free
153 * @dma_handle: DMA handle of the memory to free
154 *
155 * Managed dma_free_noncoherent().
156 */
157void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
158               dma_addr_t dma_handle)
159{
160    struct dma_devres match_data = { size, vaddr, dma_handle };
161
162    dma_free_noncoherent(dev, size, vaddr, dma_handle);
163    WARN_ON(!devres_destroy(dev, dmam_noncoherent_release, dmam_match,
164                &match_data));
165}
166EXPORT_SYMBOL(dmam_free_noncoherent);
167
168#ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
169
170static void dmam_coherent_decl_release(struct device *dev, void *res)
171{
172    dma_release_declared_memory(dev);
173}
174
175/**
176 * dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
177 * @dev: Device to declare coherent memory for
178 * @bus_addr: Bus address of coherent memory to be declared
179 * @device_addr: Device address of coherent memory to be declared
180 * @size: Size of coherent memory to be declared
181 * @flags: Flags
182 *
183 * Managed dma_declare_coherent_memory().
184 *
185 * RETURNS:
186 * 0 on success, -errno on failure.
187 */
188int dmam_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
189                 dma_addr_t device_addr, size_t size, int flags)
190{
191    void *res;
192    int rc;
193
194    res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
195    if (!res)
196        return -ENOMEM;
197
198    rc = dma_declare_coherent_memory(dev, bus_addr, device_addr, size,
199                     flags);
200    if (rc == 0)
201        devres_add(dev, res);
202    else
203        devres_free(res);
204
205    return rc;
206}
207EXPORT_SYMBOL(dmam_declare_coherent_memory);
208
209/**
210 * dmam_release_declared_memory - Managed dma_release_declared_memory().
211 * @dev: Device to release declared coherent memory for
212 *
213 * Managed dmam_release_declared_memory().
214 */
215void dmam_release_declared_memory(struct device *dev)
216{
217    WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
218}
219EXPORT_SYMBOL(dmam_release_declared_memory);
220
221#endif
222
223/*
224 * Create scatter-list for the already allocated DMA buffer.
225 */
226int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
227         void *cpu_addr, dma_addr_t handle, size_t size)
228{
229    struct page *page = virt_to_page(cpu_addr);
230    int ret;
231
232    ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
233    if (unlikely(ret))
234        return ret;
235
236    sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
237    return 0;
238}
239EXPORT_SYMBOL(dma_common_get_sgtable);
240
241/*
242 * Create userspace mapping for the DMA-coherent memory.
243 */
244int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
245            void *cpu_addr, dma_addr_t dma_addr, size_t size)
246{
247    int ret = -ENXIO;
248#ifdef CONFIG_MMU
249    unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
250    unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
251    unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
252    unsigned long off = vma->vm_pgoff;
253
254    vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
255
256    if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
257        return ret;
258
259    if (off < count && user_count <= (count - off)) {
260        ret = remap_pfn_range(vma, vma->vm_start,
261                      pfn + off,
262                      user_count << PAGE_SHIFT,
263                      vma->vm_page_prot);
264    }
265#endif /* CONFIG_MMU */
266
267    return ret;
268}
269EXPORT_SYMBOL(dma_common_mmap);
270

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