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 <linux/slab.h>
14#include <linux/vmalloc.h>
15#include <asm-generic/dma-coherent.h>
16
17/*
18 * Managed DMA API
19 */
20struct dma_devres {
21	size_t		size;
22	void		*vaddr;
23	dma_addr_t	dma_handle;
24};
25
26static void dmam_coherent_release(struct device *dev, void *res)
27{
28	struct dma_devres *this = res;
29
30	dma_free_coherent(dev, this->size, this->vaddr, this->dma_handle);
31}
32
33static void dmam_noncoherent_release(struct device *dev, void *res)
34{
35	struct dma_devres *this = res;
36
37	dma_free_noncoherent(dev, this->size, this->vaddr, this->dma_handle);
38}
39
40static int dmam_match(struct device *dev, void *res, void *match_data)
41{
42	struct dma_devres *this = res, *match = match_data;
43
44	if (this->vaddr == match->vaddr) {
45		WARN_ON(this->size != match->size ||
46			this->dma_handle != match->dma_handle);
47		return 1;
48	}
49	return 0;
50}
51
52/**
53 * dmam_alloc_coherent - Managed dma_alloc_coherent()
54 * @dev: Device to allocate coherent memory for
55 * @size: Size of allocation
56 * @dma_handle: Out argument for allocated DMA handle
57 * @gfp: Allocation flags
58 *
59 * Managed dma_alloc_coherent().  Memory allocated using this function
60 * will be automatically released on driver detach.
61 *
62 * RETURNS:
63 * Pointer to allocated memory on success, NULL on failure.
64 */
65void * dmam_alloc_coherent(struct device *dev, size_t size,
66			   dma_addr_t *dma_handle, gfp_t gfp)
67{
68	struct dma_devres *dr;
69	void *vaddr;
70
71	dr = devres_alloc(dmam_coherent_release, sizeof(*dr), gfp);
72	if (!dr)
73		return NULL;
74
75	vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
76	if (!vaddr) {
77		devres_free(dr);
78		return NULL;
79	}
80
81	dr->vaddr = vaddr;
82	dr->dma_handle = *dma_handle;
83	dr->size = size;
84
85	devres_add(dev, dr);
86
87	return vaddr;
88}
89EXPORT_SYMBOL(dmam_alloc_coherent);
90
91/**
92 * dmam_free_coherent - Managed dma_free_coherent()
93 * @dev: Device to free coherent memory for
94 * @size: Size of allocation
95 * @vaddr: Virtual address of the memory to free
96 * @dma_handle: DMA handle of the memory to free
97 *
98 * Managed dma_free_coherent().
99 */
100void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
101			dma_addr_t dma_handle)
102{
103	struct dma_devres match_data = { size, vaddr, dma_handle };
104
105	dma_free_coherent(dev, size, vaddr, dma_handle);
106	WARN_ON(devres_destroy(dev, dmam_coherent_release, dmam_match,
107			       &match_data));
108}
109EXPORT_SYMBOL(dmam_free_coherent);
110
111/**
112 * dmam_alloc_non_coherent - Managed dma_alloc_non_coherent()
113 * @dev: Device to allocate non_coherent memory for
114 * @size: Size of allocation
115 * @dma_handle: Out argument for allocated DMA handle
116 * @gfp: Allocation flags
117 *
118 * Managed dma_alloc_non_coherent().  Memory allocated using this
119 * function will be automatically released on driver detach.
120 *
121 * RETURNS:
122 * Pointer to allocated memory on success, NULL on failure.
123 */
124void *dmam_alloc_noncoherent(struct device *dev, size_t size,
125			     dma_addr_t *dma_handle, gfp_t gfp)
126{
127	struct dma_devres *dr;
128	void *vaddr;
129
130	dr = devres_alloc(dmam_noncoherent_release, sizeof(*dr), gfp);
131	if (!dr)
132		return NULL;
133
134	vaddr = dma_alloc_noncoherent(dev, size, dma_handle, gfp);
135	if (!vaddr) {
136		devres_free(dr);
137		return NULL;
138	}
139
140	dr->vaddr = vaddr;
141	dr->dma_handle = *dma_handle;
142	dr->size = size;
143
144	devres_add(dev, dr);
145
146	return vaddr;
147}
148EXPORT_SYMBOL(dmam_alloc_noncoherent);
149
150/**
151 * dmam_free_coherent - Managed dma_free_noncoherent()
152 * @dev: Device to free noncoherent memory for
153 * @size: Size of allocation
154 * @vaddr: Virtual address of the memory to free
155 * @dma_handle: DMA handle of the memory to free
156 *
157 * Managed dma_free_noncoherent().
158 */
159void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
160			   dma_addr_t dma_handle)
161{
162	struct dma_devres match_data = { size, vaddr, dma_handle };
163
164	dma_free_noncoherent(dev, size, vaddr, dma_handle);
165	WARN_ON(!devres_destroy(dev, dmam_noncoherent_release, dmam_match,
166				&match_data));
167}
168EXPORT_SYMBOL(dmam_free_noncoherent);
169
170#ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
171
172static void dmam_coherent_decl_release(struct device *dev, void *res)
173{
174	dma_release_declared_memory(dev);
175}
176
177/**
178 * dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
179 * @dev: Device to declare coherent memory for
180 * @phys_addr: Physical address of coherent memory to be declared
181 * @device_addr: Device address of coherent memory to be declared
182 * @size: Size of coherent memory to be declared
183 * @flags: Flags
184 *
185 * Managed dma_declare_coherent_memory().
186 *
187 * RETURNS:
188 * 0 on success, -errno on failure.
189 */
190int dmam_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
191				 dma_addr_t device_addr, size_t size, int flags)
192{
193	void *res;
194	int rc;
195
196	res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
197	if (!res)
198		return -ENOMEM;
199
200	rc = dma_declare_coherent_memory(dev, phys_addr, device_addr, size,
201					 flags);
202	if (rc == 0)
203		devres_add(dev, res);
204	else
205		devres_free(res);
206
207	return rc;
208}
209EXPORT_SYMBOL(dmam_declare_coherent_memory);
210
211/**
212 * dmam_release_declared_memory - Managed dma_release_declared_memory().
213 * @dev: Device to release declared coherent memory for
214 *
215 * Managed dmam_release_declared_memory().
216 */
217void dmam_release_declared_memory(struct device *dev)
218{
219	WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
220}
221EXPORT_SYMBOL(dmam_release_declared_memory);
222
223#endif
224
225/*
226 * Create scatter-list for the already allocated DMA buffer.
227 */
228int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
229		 void *cpu_addr, dma_addr_t handle, size_t size)
230{
231	struct page *page = virt_to_page(cpu_addr);
232	int ret;
233
234	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
235	if (unlikely(ret))
236		return ret;
237
238	sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
239	return 0;
240}
241EXPORT_SYMBOL(dma_common_get_sgtable);
242
243/*
244 * Create userspace mapping for the DMA-coherent memory.
245 */
246int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
247		    void *cpu_addr, dma_addr_t dma_addr, size_t size)
248{
249	int ret = -ENXIO;
250#ifdef CONFIG_MMU
251	unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
252	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
253	unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
254	unsigned long off = vma->vm_pgoff;
255
256	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
257
258	if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
259		return ret;
260
261	if (off < count && user_count <= (count - off)) {
262		ret = remap_pfn_range(vma, vma->vm_start,
263				      pfn + off,
264				      user_count << PAGE_SHIFT,
265				      vma->vm_page_prot);
266	}
267#endif	/* CONFIG_MMU */
268
269	return ret;
270}
271EXPORT_SYMBOL(dma_common_mmap);
272
273#ifdef CONFIG_MMU
274/*
275 * remaps an array of PAGE_SIZE pages into another vm_area
276 * Cannot be used in non-sleeping contexts
277 */
278void *dma_common_pages_remap(struct page **pages, size_t size,
279			unsigned long vm_flags, pgprot_t prot,
280			const void *caller)
281{
282	struct vm_struct *area;
283
284	area = get_vm_area_caller(size, vm_flags, caller);
285	if (!area)
286		return NULL;
287
288	area->pages = pages;
289
290	if (map_vm_area(area, prot, pages)) {
291		vunmap(area->addr);
292		return NULL;
293	}
294
295	return area->addr;
296}
297
298/*
299 * remaps an allocated contiguous region into another vm_area.
300 * Cannot be used in non-sleeping contexts
301 */
302
303void *dma_common_contiguous_remap(struct page *page, size_t size,
304			unsigned long vm_flags,
305			pgprot_t prot, const void *caller)
306{
307	int i;
308	struct page **pages;
309	void *ptr;
310	unsigned long pfn;
311
312	pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
313	if (!pages)
314		return NULL;
315
316	for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++)
317		pages[i] = pfn_to_page(pfn + i);
318
319	ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller);
320
321	kfree(pages);
322
323	return ptr;
324}
325
326/*
327 * unmaps a range previously mapped by dma_common_*_remap
328 */
329void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
330{
331	struct vm_struct *area = find_vm_area(cpu_addr);
332
333	if (!area || (area->flags & vm_flags) != vm_flags) {
334		WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
335		return;
336	}
337
338	unmap_kernel_range((unsigned long)cpu_addr, size);
339	vunmap(cpu_addr);
340}
341#endif
342