Commit | Line | Data |
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5ba3f757 AP |
1 | /* |
2 | * videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2 | |
3 | * | |
4 | * Copyright (C) 2010 Samsung Electronics | |
5 | * | |
6 | * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/scatterlist.h> | |
16 | #include <linux/sched.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/vmalloc.h> | |
19 | ||
20 | #include <media/videobuf2-core.h> | |
21 | #include <media/videobuf2-memops.h> | |
22 | #include <media/videobuf2-dma-sg.h> | |
23 | ||
ffdc78ef HV |
24 | static int debug; |
25 | module_param(debug, int, 0644); | |
26 | ||
27 | #define dprintk(level, fmt, arg...) \ | |
28 | do { \ | |
29 | if (debug >= level) \ | |
30 | printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg); \ | |
31 | } while (0) | |
32 | ||
5ba3f757 AP |
33 | struct vb2_dma_sg_buf { |
34 | void *vaddr; | |
35 | struct page **pages; | |
5ba3f757 | 36 | int offset; |
cd474037 | 37 | enum dma_data_direction dma_dir; |
22301247 RR |
38 | struct sg_table sg_table; |
39 | size_t size; | |
40 | unsigned int num_pages; | |
5ba3f757 AP |
41 | atomic_t refcount; |
42 | struct vb2_vmarea_handler handler; | |
50ac952d | 43 | struct vm_area_struct *vma; |
5ba3f757 AP |
44 | }; |
45 | ||
46 | static void vb2_dma_sg_put(void *buf_priv); | |
47 | ||
df237281 RR |
48 | static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf, |
49 | gfp_t gfp_flags) | |
50 | { | |
51 | unsigned int last_page = 0; | |
22301247 | 52 | int size = buf->size; |
df237281 RR |
53 | |
54 | while (size > 0) { | |
55 | struct page *pages; | |
56 | int order; | |
57 | int i; | |
58 | ||
59 | order = get_order(size); | |
60 | /* Dont over allocate*/ | |
61 | if ((PAGE_SIZE << order) > size) | |
62 | order--; | |
63 | ||
64 | pages = NULL; | |
65 | while (!pages) { | |
66 | pages = alloc_pages(GFP_KERNEL | __GFP_ZERO | | |
67 | __GFP_NOWARN | gfp_flags, order); | |
68 | if (pages) | |
69 | break; | |
70 | ||
71 | if (order == 0) { | |
72 | while (last_page--) | |
73 | __free_page(buf->pages[last_page]); | |
74 | return -ENOMEM; | |
75 | } | |
76 | order--; | |
77 | } | |
78 | ||
79 | split_page(pages, order); | |
22301247 RR |
80 | for (i = 0; i < (1 << order); i++) |
81 | buf->pages[last_page++] = &pages[i]; | |
df237281 RR |
82 | |
83 | size -= PAGE_SIZE << order; | |
84 | } | |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
b6ba2057 | 89 | static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_flags) |
5ba3f757 AP |
90 | { |
91 | struct vb2_dma_sg_buf *buf; | |
df237281 | 92 | int ret; |
22301247 | 93 | int num_pages; |
5ba3f757 AP |
94 | |
95 | buf = kzalloc(sizeof *buf, GFP_KERNEL); | |
96 | if (!buf) | |
97 | return NULL; | |
98 | ||
99 | buf->vaddr = NULL; | |
cd474037 | 100 | buf->dma_dir = DMA_NONE; |
5ba3f757 | 101 | buf->offset = 0; |
22301247 | 102 | buf->size = size; |
7f841459 | 103 | /* size is already page aligned */ |
22301247 | 104 | buf->num_pages = size >> PAGE_SHIFT; |
5ba3f757 | 105 | |
22301247 | 106 | buf->pages = kzalloc(buf->num_pages * sizeof(struct page *), |
5ba3f757 AP |
107 | GFP_KERNEL); |
108 | if (!buf->pages) | |
109 | goto fail_pages_array_alloc; | |
110 | ||
df237281 RR |
111 | ret = vb2_dma_sg_alloc_compacted(buf, gfp_flags); |
112 | if (ret) | |
113 | goto fail_pages_alloc; | |
5ba3f757 | 114 | |
22301247 | 115 | ret = sg_alloc_table_from_pages(&buf->sg_table, buf->pages, |
47bc59c5 | 116 | buf->num_pages, 0, size, GFP_KERNEL); |
22301247 RR |
117 | if (ret) |
118 | goto fail_table_alloc; | |
119 | ||
5ba3f757 AP |
120 | buf->handler.refcount = &buf->refcount; |
121 | buf->handler.put = vb2_dma_sg_put; | |
122 | buf->handler.arg = buf; | |
123 | ||
124 | atomic_inc(&buf->refcount); | |
125 | ||
ffdc78ef | 126 | dprintk(1, "%s: Allocated buffer of %d pages\n", |
22301247 | 127 | __func__, buf->num_pages); |
5ba3f757 AP |
128 | return buf; |
129 | ||
22301247 RR |
130 | fail_table_alloc: |
131 | num_pages = buf->num_pages; | |
132 | while (num_pages--) | |
133 | __free_page(buf->pages[num_pages]); | |
5ba3f757 | 134 | fail_pages_alloc: |
a9bb36aa | 135 | kfree(buf->pages); |
5ba3f757 | 136 | fail_pages_array_alloc: |
5ba3f757 AP |
137 | kfree(buf); |
138 | return NULL; | |
139 | } | |
140 | ||
141 | static void vb2_dma_sg_put(void *buf_priv) | |
142 | { | |
143 | struct vb2_dma_sg_buf *buf = buf_priv; | |
22301247 | 144 | int i = buf->num_pages; |
5ba3f757 AP |
145 | |
146 | if (atomic_dec_and_test(&buf->refcount)) { | |
ffdc78ef | 147 | dprintk(1, "%s: Freeing buffer of %d pages\n", __func__, |
22301247 | 148 | buf->num_pages); |
5ba3f757 | 149 | if (buf->vaddr) |
22301247 RR |
150 | vm_unmap_ram(buf->vaddr, buf->num_pages); |
151 | sg_free_table(&buf->sg_table); | |
5ba3f757 AP |
152 | while (--i >= 0) |
153 | __free_page(buf->pages[i]); | |
154 | kfree(buf->pages); | |
155 | kfree(buf); | |
156 | } | |
157 | } | |
158 | ||
50ac952d RR |
159 | static inline int vma_is_io(struct vm_area_struct *vma) |
160 | { | |
161 | return !!(vma->vm_flags & (VM_IO | VM_PFNMAP)); | |
162 | } | |
163 | ||
5ba3f757 | 164 | static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, |
cd474037 HV |
165 | unsigned long size, |
166 | enum dma_data_direction dma_dir) | |
5ba3f757 AP |
167 | { |
168 | struct vb2_dma_sg_buf *buf; | |
169 | unsigned long first, last; | |
22301247 | 170 | int num_pages_from_user; |
50ac952d | 171 | struct vm_area_struct *vma; |
5ba3f757 AP |
172 | |
173 | buf = kzalloc(sizeof *buf, GFP_KERNEL); | |
174 | if (!buf) | |
175 | return NULL; | |
176 | ||
177 | buf->vaddr = NULL; | |
cd474037 | 178 | buf->dma_dir = dma_dir; |
5ba3f757 | 179 | buf->offset = vaddr & ~PAGE_MASK; |
22301247 | 180 | buf->size = size; |
5ba3f757 AP |
181 | |
182 | first = (vaddr & PAGE_MASK) >> PAGE_SHIFT; | |
183 | last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT; | |
22301247 | 184 | buf->num_pages = last - first + 1; |
5ba3f757 | 185 | |
22301247 | 186 | buf->pages = kzalloc(buf->num_pages * sizeof(struct page *), |
5ba3f757 AP |
187 | GFP_KERNEL); |
188 | if (!buf->pages) | |
64c832a4 | 189 | goto userptr_fail_alloc_pages; |
5ba3f757 | 190 | |
50ac952d RR |
191 | vma = find_vma(current->mm, vaddr); |
192 | if (!vma) { | |
193 | dprintk(1, "no vma for address %lu\n", vaddr); | |
194 | goto userptr_fail_find_vma; | |
195 | } | |
196 | ||
197 | if (vma->vm_end < vaddr + size) { | |
198 | dprintk(1, "vma at %lu is too small for %lu bytes\n", | |
199 | vaddr, size); | |
200 | goto userptr_fail_find_vma; | |
201 | } | |
202 | ||
203 | buf->vma = vb2_get_vma(vma); | |
204 | if (!buf->vma) { | |
205 | dprintk(1, "failed to copy vma\n"); | |
206 | goto userptr_fail_find_vma; | |
207 | } | |
208 | ||
209 | if (vma_is_io(buf->vma)) { | |
210 | for (num_pages_from_user = 0; | |
211 | num_pages_from_user < buf->num_pages; | |
212 | ++num_pages_from_user, vaddr += PAGE_SIZE) { | |
213 | unsigned long pfn; | |
214 | ||
227ae227 | 215 | if (follow_pfn(vma, vaddr, &pfn)) { |
50ac952d RR |
216 | dprintk(1, "no page for address %lu\n", vaddr); |
217 | break; | |
218 | } | |
219 | buf->pages[num_pages_from_user] = pfn_to_page(pfn); | |
220 | } | |
221 | } else | |
222 | num_pages_from_user = get_user_pages(current, current->mm, | |
5ba3f757 | 223 | vaddr & PAGE_MASK, |
22301247 | 224 | buf->num_pages, |
cd474037 | 225 | buf->dma_dir == DMA_FROM_DEVICE, |
5ba3f757 AP |
226 | 1, /* force */ |
227 | buf->pages, | |
228 | NULL); | |
b037c0fd | 229 | |
22301247 | 230 | if (num_pages_from_user != buf->num_pages) |
5ba3f757 AP |
231 | goto userptr_fail_get_user_pages; |
232 | ||
22301247 RR |
233 | if (sg_alloc_table_from_pages(&buf->sg_table, buf->pages, |
234 | buf->num_pages, buf->offset, size, 0)) | |
235 | goto userptr_fail_alloc_table_from_pages; | |
236 | ||
5ba3f757 AP |
237 | return buf; |
238 | ||
22301247 | 239 | userptr_fail_alloc_table_from_pages: |
5ba3f757 | 240 | userptr_fail_get_user_pages: |
ffdc78ef | 241 | dprintk(1, "get_user_pages requested/got: %d/%d]\n", |
202dfbdc | 242 | buf->num_pages, num_pages_from_user); |
50ac952d RR |
243 | if (!vma_is_io(buf->vma)) |
244 | while (--num_pages_from_user >= 0) | |
245 | put_page(buf->pages[num_pages_from_user]); | |
246 | vb2_put_vma(buf->vma); | |
247 | userptr_fail_find_vma: | |
a9bb36aa | 248 | kfree(buf->pages); |
64c832a4 | 249 | userptr_fail_alloc_pages: |
5ba3f757 AP |
250 | kfree(buf); |
251 | return NULL; | |
252 | } | |
253 | ||
254 | /* | |
255 | * @put_userptr: inform the allocator that a USERPTR buffer will no longer | |
256 | * be used | |
257 | */ | |
258 | static void vb2_dma_sg_put_userptr(void *buf_priv) | |
259 | { | |
260 | struct vb2_dma_sg_buf *buf = buf_priv; | |
22301247 | 261 | int i = buf->num_pages; |
5ba3f757 | 262 | |
ffdc78ef | 263 | dprintk(1, "%s: Releasing userspace buffer of %d pages\n", |
22301247 | 264 | __func__, buf->num_pages); |
5ba3f757 | 265 | if (buf->vaddr) |
22301247 RR |
266 | vm_unmap_ram(buf->vaddr, buf->num_pages); |
267 | sg_free_table(&buf->sg_table); | |
5ba3f757 | 268 | while (--i >= 0) { |
cd474037 | 269 | if (buf->dma_dir == DMA_FROM_DEVICE) |
5ba3f757 | 270 | set_page_dirty_lock(buf->pages[i]); |
50ac952d RR |
271 | if (!vma_is_io(buf->vma)) |
272 | put_page(buf->pages[i]); | |
5ba3f757 | 273 | } |
5ba3f757 | 274 | kfree(buf->pages); |
50ac952d | 275 | vb2_put_vma(buf->vma); |
5ba3f757 AP |
276 | kfree(buf); |
277 | } | |
278 | ||
279 | static void *vb2_dma_sg_vaddr(void *buf_priv) | |
280 | { | |
281 | struct vb2_dma_sg_buf *buf = buf_priv; | |
282 | ||
283 | BUG_ON(!buf); | |
284 | ||
285 | if (!buf->vaddr) | |
286 | buf->vaddr = vm_map_ram(buf->pages, | |
22301247 | 287 | buf->num_pages, |
5ba3f757 AP |
288 | -1, |
289 | PAGE_KERNEL); | |
290 | ||
291 | /* add offset in case userptr is not page-aligned */ | |
292 | return buf->vaddr + buf->offset; | |
293 | } | |
294 | ||
295 | static unsigned int vb2_dma_sg_num_users(void *buf_priv) | |
296 | { | |
297 | struct vb2_dma_sg_buf *buf = buf_priv; | |
298 | ||
299 | return atomic_read(&buf->refcount); | |
300 | } | |
301 | ||
302 | static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma) | |
303 | { | |
304 | struct vb2_dma_sg_buf *buf = buf_priv; | |
305 | unsigned long uaddr = vma->vm_start; | |
306 | unsigned long usize = vma->vm_end - vma->vm_start; | |
307 | int i = 0; | |
308 | ||
309 | if (!buf) { | |
310 | printk(KERN_ERR "No memory to map\n"); | |
311 | return -EINVAL; | |
312 | } | |
313 | ||
314 | do { | |
315 | int ret; | |
316 | ||
317 | ret = vm_insert_page(vma, uaddr, buf->pages[i++]); | |
318 | if (ret) { | |
319 | printk(KERN_ERR "Remapping memory, error: %d\n", ret); | |
320 | return ret; | |
321 | } | |
322 | ||
323 | uaddr += PAGE_SIZE; | |
324 | usize -= PAGE_SIZE; | |
325 | } while (usize > 0); | |
326 | ||
327 | ||
328 | /* | |
329 | * Use common vm_area operations to track buffer refcount. | |
330 | */ | |
331 | vma->vm_private_data = &buf->handler; | |
332 | vma->vm_ops = &vb2_common_vm_ops; | |
333 | ||
334 | vma->vm_ops->open(vma); | |
335 | ||
336 | return 0; | |
337 | } | |
338 | ||
339 | static void *vb2_dma_sg_cookie(void *buf_priv) | |
340 | { | |
341 | struct vb2_dma_sg_buf *buf = buf_priv; | |
342 | ||
22301247 | 343 | return &buf->sg_table; |
5ba3f757 AP |
344 | } |
345 | ||
346 | const struct vb2_mem_ops vb2_dma_sg_memops = { | |
347 | .alloc = vb2_dma_sg_alloc, | |
348 | .put = vb2_dma_sg_put, | |
349 | .get_userptr = vb2_dma_sg_get_userptr, | |
350 | .put_userptr = vb2_dma_sg_put_userptr, | |
351 | .vaddr = vb2_dma_sg_vaddr, | |
352 | .mmap = vb2_dma_sg_mmap, | |
353 | .num_users = vb2_dma_sg_num_users, | |
354 | .cookie = vb2_dma_sg_cookie, | |
355 | }; | |
356 | EXPORT_SYMBOL_GPL(vb2_dma_sg_memops); | |
357 | ||
358 | MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2"); | |
359 | MODULE_AUTHOR("Andrzej Pietrasiewicz"); | |
360 | MODULE_LICENSE("GPL"); |