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 | ||
0c3a14c1 HV |
33 | struct vb2_dma_sg_conf { |
34 | struct device *dev; | |
35 | }; | |
36 | ||
5ba3f757 | 37 | struct vb2_dma_sg_buf { |
0c3a14c1 | 38 | struct device *dev; |
5ba3f757 AP |
39 | void *vaddr; |
40 | struct page **pages; | |
5ba3f757 | 41 | int offset; |
cd474037 | 42 | enum dma_data_direction dma_dir; |
22301247 RR |
43 | struct sg_table sg_table; |
44 | size_t size; | |
45 | unsigned int num_pages; | |
5ba3f757 AP |
46 | atomic_t refcount; |
47 | struct vb2_vmarea_handler handler; | |
50ac952d | 48 | struct vm_area_struct *vma; |
5ba3f757 AP |
49 | }; |
50 | ||
51 | static void vb2_dma_sg_put(void *buf_priv); | |
52 | ||
df237281 RR |
53 | static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf, |
54 | gfp_t gfp_flags) | |
55 | { | |
56 | unsigned int last_page = 0; | |
22301247 | 57 | int size = buf->size; |
df237281 RR |
58 | |
59 | while (size > 0) { | |
60 | struct page *pages; | |
61 | int order; | |
62 | int i; | |
63 | ||
64 | order = get_order(size); | |
65 | /* Dont over allocate*/ | |
66 | if ((PAGE_SIZE << order) > size) | |
67 | order--; | |
68 | ||
69 | pages = NULL; | |
70 | while (!pages) { | |
71 | pages = alloc_pages(GFP_KERNEL | __GFP_ZERO | | |
72 | __GFP_NOWARN | gfp_flags, order); | |
73 | if (pages) | |
74 | break; | |
75 | ||
76 | if (order == 0) { | |
77 | while (last_page--) | |
78 | __free_page(buf->pages[last_page]); | |
79 | return -ENOMEM; | |
80 | } | |
81 | order--; | |
82 | } | |
83 | ||
84 | split_page(pages, order); | |
22301247 RR |
85 | for (i = 0; i < (1 << order); i++) |
86 | buf->pages[last_page++] = &pages[i]; | |
df237281 RR |
87 | |
88 | size -= PAGE_SIZE << order; | |
89 | } | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
d935c57e HV |
94 | static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, |
95 | enum dma_data_direction dma_dir, gfp_t gfp_flags) | |
5ba3f757 | 96 | { |
0c3a14c1 | 97 | struct vb2_dma_sg_conf *conf = alloc_ctx; |
5ba3f757 | 98 | struct vb2_dma_sg_buf *buf; |
df237281 | 99 | int ret; |
22301247 | 100 | int num_pages; |
5ba3f757 | 101 | |
0c3a14c1 HV |
102 | if (WARN_ON(alloc_ctx == NULL)) |
103 | return NULL; | |
5ba3f757 AP |
104 | buf = kzalloc(sizeof *buf, GFP_KERNEL); |
105 | if (!buf) | |
106 | return NULL; | |
107 | ||
108 | buf->vaddr = NULL; | |
d935c57e | 109 | buf->dma_dir = dma_dir; |
5ba3f757 | 110 | buf->offset = 0; |
22301247 | 111 | buf->size = size; |
7f841459 | 112 | /* size is already page aligned */ |
22301247 | 113 | buf->num_pages = size >> PAGE_SHIFT; |
5ba3f757 | 114 | |
22301247 | 115 | buf->pages = kzalloc(buf->num_pages * sizeof(struct page *), |
5ba3f757 AP |
116 | GFP_KERNEL); |
117 | if (!buf->pages) | |
118 | goto fail_pages_array_alloc; | |
119 | ||
df237281 RR |
120 | ret = vb2_dma_sg_alloc_compacted(buf, gfp_flags); |
121 | if (ret) | |
122 | goto fail_pages_alloc; | |
5ba3f757 | 123 | |
22301247 | 124 | ret = sg_alloc_table_from_pages(&buf->sg_table, buf->pages, |
47bc59c5 | 125 | buf->num_pages, 0, size, GFP_KERNEL); |
22301247 RR |
126 | if (ret) |
127 | goto fail_table_alloc; | |
128 | ||
0c3a14c1 HV |
129 | /* Prevent the device from being released while the buffer is used */ |
130 | buf->dev = get_device(conf->dev); | |
5ba3f757 AP |
131 | buf->handler.refcount = &buf->refcount; |
132 | buf->handler.put = vb2_dma_sg_put; | |
133 | buf->handler.arg = buf; | |
134 | ||
135 | atomic_inc(&buf->refcount); | |
136 | ||
ffdc78ef | 137 | dprintk(1, "%s: Allocated buffer of %d pages\n", |
22301247 | 138 | __func__, buf->num_pages); |
5ba3f757 AP |
139 | return buf; |
140 | ||
22301247 RR |
141 | fail_table_alloc: |
142 | num_pages = buf->num_pages; | |
143 | while (num_pages--) | |
144 | __free_page(buf->pages[num_pages]); | |
5ba3f757 | 145 | fail_pages_alloc: |
a9bb36aa | 146 | kfree(buf->pages); |
5ba3f757 | 147 | fail_pages_array_alloc: |
5ba3f757 AP |
148 | kfree(buf); |
149 | return NULL; | |
150 | } | |
151 | ||
152 | static void vb2_dma_sg_put(void *buf_priv) | |
153 | { | |
154 | struct vb2_dma_sg_buf *buf = buf_priv; | |
22301247 | 155 | int i = buf->num_pages; |
5ba3f757 AP |
156 | |
157 | if (atomic_dec_and_test(&buf->refcount)) { | |
ffdc78ef | 158 | dprintk(1, "%s: Freeing buffer of %d pages\n", __func__, |
22301247 | 159 | buf->num_pages); |
5ba3f757 | 160 | if (buf->vaddr) |
22301247 RR |
161 | vm_unmap_ram(buf->vaddr, buf->num_pages); |
162 | sg_free_table(&buf->sg_table); | |
5ba3f757 AP |
163 | while (--i >= 0) |
164 | __free_page(buf->pages[i]); | |
165 | kfree(buf->pages); | |
0c3a14c1 | 166 | put_device(buf->dev); |
5ba3f757 AP |
167 | kfree(buf); |
168 | } | |
169 | } | |
170 | ||
50ac952d RR |
171 | static inline int vma_is_io(struct vm_area_struct *vma) |
172 | { | |
173 | return !!(vma->vm_flags & (VM_IO | VM_PFNMAP)); | |
174 | } | |
175 | ||
5ba3f757 | 176 | static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, |
cd474037 HV |
177 | unsigned long size, |
178 | enum dma_data_direction dma_dir) | |
5ba3f757 AP |
179 | { |
180 | struct vb2_dma_sg_buf *buf; | |
181 | unsigned long first, last; | |
22301247 | 182 | int num_pages_from_user; |
50ac952d | 183 | struct vm_area_struct *vma; |
5ba3f757 AP |
184 | |
185 | buf = kzalloc(sizeof *buf, GFP_KERNEL); | |
186 | if (!buf) | |
187 | return NULL; | |
188 | ||
189 | buf->vaddr = NULL; | |
cd474037 | 190 | buf->dma_dir = dma_dir; |
5ba3f757 | 191 | buf->offset = vaddr & ~PAGE_MASK; |
22301247 | 192 | buf->size = size; |
5ba3f757 AP |
193 | |
194 | first = (vaddr & PAGE_MASK) >> PAGE_SHIFT; | |
195 | last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT; | |
22301247 | 196 | buf->num_pages = last - first + 1; |
5ba3f757 | 197 | |
22301247 | 198 | buf->pages = kzalloc(buf->num_pages * sizeof(struct page *), |
5ba3f757 AP |
199 | GFP_KERNEL); |
200 | if (!buf->pages) | |
64c832a4 | 201 | goto userptr_fail_alloc_pages; |
5ba3f757 | 202 | |
50ac952d RR |
203 | vma = find_vma(current->mm, vaddr); |
204 | if (!vma) { | |
205 | dprintk(1, "no vma for address %lu\n", vaddr); | |
206 | goto userptr_fail_find_vma; | |
207 | } | |
208 | ||
209 | if (vma->vm_end < vaddr + size) { | |
210 | dprintk(1, "vma at %lu is too small for %lu bytes\n", | |
211 | vaddr, size); | |
212 | goto userptr_fail_find_vma; | |
213 | } | |
214 | ||
215 | buf->vma = vb2_get_vma(vma); | |
216 | if (!buf->vma) { | |
217 | dprintk(1, "failed to copy vma\n"); | |
218 | goto userptr_fail_find_vma; | |
219 | } | |
220 | ||
221 | if (vma_is_io(buf->vma)) { | |
222 | for (num_pages_from_user = 0; | |
223 | num_pages_from_user < buf->num_pages; | |
224 | ++num_pages_from_user, vaddr += PAGE_SIZE) { | |
225 | unsigned long pfn; | |
226 | ||
227ae227 | 227 | if (follow_pfn(vma, vaddr, &pfn)) { |
50ac952d RR |
228 | dprintk(1, "no page for address %lu\n", vaddr); |
229 | break; | |
230 | } | |
231 | buf->pages[num_pages_from_user] = pfn_to_page(pfn); | |
232 | } | |
233 | } else | |
234 | num_pages_from_user = get_user_pages(current, current->mm, | |
5ba3f757 | 235 | vaddr & PAGE_MASK, |
22301247 | 236 | buf->num_pages, |
cd474037 | 237 | buf->dma_dir == DMA_FROM_DEVICE, |
5ba3f757 AP |
238 | 1, /* force */ |
239 | buf->pages, | |
240 | NULL); | |
b037c0fd | 241 | |
22301247 | 242 | if (num_pages_from_user != buf->num_pages) |
5ba3f757 AP |
243 | goto userptr_fail_get_user_pages; |
244 | ||
22301247 RR |
245 | if (sg_alloc_table_from_pages(&buf->sg_table, buf->pages, |
246 | buf->num_pages, buf->offset, size, 0)) | |
247 | goto userptr_fail_alloc_table_from_pages; | |
248 | ||
5ba3f757 AP |
249 | return buf; |
250 | ||
22301247 | 251 | userptr_fail_alloc_table_from_pages: |
5ba3f757 | 252 | userptr_fail_get_user_pages: |
ffdc78ef | 253 | dprintk(1, "get_user_pages requested/got: %d/%d]\n", |
202dfbdc | 254 | buf->num_pages, num_pages_from_user); |
50ac952d RR |
255 | if (!vma_is_io(buf->vma)) |
256 | while (--num_pages_from_user >= 0) | |
257 | put_page(buf->pages[num_pages_from_user]); | |
258 | vb2_put_vma(buf->vma); | |
259 | userptr_fail_find_vma: | |
a9bb36aa | 260 | kfree(buf->pages); |
64c832a4 | 261 | userptr_fail_alloc_pages: |
5ba3f757 AP |
262 | kfree(buf); |
263 | return NULL; | |
264 | } | |
265 | ||
266 | /* | |
267 | * @put_userptr: inform the allocator that a USERPTR buffer will no longer | |
268 | * be used | |
269 | */ | |
270 | static void vb2_dma_sg_put_userptr(void *buf_priv) | |
271 | { | |
272 | struct vb2_dma_sg_buf *buf = buf_priv; | |
22301247 | 273 | int i = buf->num_pages; |
5ba3f757 | 274 | |
ffdc78ef | 275 | dprintk(1, "%s: Releasing userspace buffer of %d pages\n", |
22301247 | 276 | __func__, buf->num_pages); |
5ba3f757 | 277 | if (buf->vaddr) |
22301247 RR |
278 | vm_unmap_ram(buf->vaddr, buf->num_pages); |
279 | sg_free_table(&buf->sg_table); | |
5ba3f757 | 280 | while (--i >= 0) { |
cd474037 | 281 | if (buf->dma_dir == DMA_FROM_DEVICE) |
5ba3f757 | 282 | set_page_dirty_lock(buf->pages[i]); |
50ac952d RR |
283 | if (!vma_is_io(buf->vma)) |
284 | put_page(buf->pages[i]); | |
5ba3f757 | 285 | } |
5ba3f757 | 286 | kfree(buf->pages); |
50ac952d | 287 | vb2_put_vma(buf->vma); |
5ba3f757 AP |
288 | kfree(buf); |
289 | } | |
290 | ||
291 | static void *vb2_dma_sg_vaddr(void *buf_priv) | |
292 | { | |
293 | struct vb2_dma_sg_buf *buf = buf_priv; | |
294 | ||
295 | BUG_ON(!buf); | |
296 | ||
297 | if (!buf->vaddr) | |
298 | buf->vaddr = vm_map_ram(buf->pages, | |
22301247 | 299 | buf->num_pages, |
5ba3f757 AP |
300 | -1, |
301 | PAGE_KERNEL); | |
302 | ||
303 | /* add offset in case userptr is not page-aligned */ | |
304 | return buf->vaddr + buf->offset; | |
305 | } | |
306 | ||
307 | static unsigned int vb2_dma_sg_num_users(void *buf_priv) | |
308 | { | |
309 | struct vb2_dma_sg_buf *buf = buf_priv; | |
310 | ||
311 | return atomic_read(&buf->refcount); | |
312 | } | |
313 | ||
314 | static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma) | |
315 | { | |
316 | struct vb2_dma_sg_buf *buf = buf_priv; | |
317 | unsigned long uaddr = vma->vm_start; | |
318 | unsigned long usize = vma->vm_end - vma->vm_start; | |
319 | int i = 0; | |
320 | ||
321 | if (!buf) { | |
322 | printk(KERN_ERR "No memory to map\n"); | |
323 | return -EINVAL; | |
324 | } | |
325 | ||
326 | do { | |
327 | int ret; | |
328 | ||
329 | ret = vm_insert_page(vma, uaddr, buf->pages[i++]); | |
330 | if (ret) { | |
331 | printk(KERN_ERR "Remapping memory, error: %d\n", ret); | |
332 | return ret; | |
333 | } | |
334 | ||
335 | uaddr += PAGE_SIZE; | |
336 | usize -= PAGE_SIZE; | |
337 | } while (usize > 0); | |
338 | ||
339 | ||
340 | /* | |
341 | * Use common vm_area operations to track buffer refcount. | |
342 | */ | |
343 | vma->vm_private_data = &buf->handler; | |
344 | vma->vm_ops = &vb2_common_vm_ops; | |
345 | ||
346 | vma->vm_ops->open(vma); | |
347 | ||
348 | return 0; | |
349 | } | |
350 | ||
351 | static void *vb2_dma_sg_cookie(void *buf_priv) | |
352 | { | |
353 | struct vb2_dma_sg_buf *buf = buf_priv; | |
354 | ||
22301247 | 355 | return &buf->sg_table; |
5ba3f757 AP |
356 | } |
357 | ||
358 | const struct vb2_mem_ops vb2_dma_sg_memops = { | |
359 | .alloc = vb2_dma_sg_alloc, | |
360 | .put = vb2_dma_sg_put, | |
361 | .get_userptr = vb2_dma_sg_get_userptr, | |
362 | .put_userptr = vb2_dma_sg_put_userptr, | |
363 | .vaddr = vb2_dma_sg_vaddr, | |
364 | .mmap = vb2_dma_sg_mmap, | |
365 | .num_users = vb2_dma_sg_num_users, | |
366 | .cookie = vb2_dma_sg_cookie, | |
367 | }; | |
368 | EXPORT_SYMBOL_GPL(vb2_dma_sg_memops); | |
369 | ||
0c3a14c1 HV |
370 | void *vb2_dma_sg_init_ctx(struct device *dev) |
371 | { | |
372 | struct vb2_dma_sg_conf *conf; | |
373 | ||
374 | conf = kzalloc(sizeof(*conf), GFP_KERNEL); | |
375 | if (!conf) | |
376 | return ERR_PTR(-ENOMEM); | |
377 | ||
378 | conf->dev = dev; | |
379 | ||
380 | return conf; | |
381 | } | |
382 | EXPORT_SYMBOL_GPL(vb2_dma_sg_init_ctx); | |
383 | ||
384 | void vb2_dma_sg_cleanup_ctx(void *alloc_ctx) | |
385 | { | |
386 | if (!IS_ERR_OR_NULL(alloc_ctx)) | |
387 | kfree(alloc_ctx); | |
388 | } | |
389 | EXPORT_SYMBOL_GPL(vb2_dma_sg_cleanup_ctx); | |
390 | ||
5ba3f757 AP |
391 | MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2"); |
392 | MODULE_AUTHOR("Andrzej Pietrasiewicz"); | |
393 | MODULE_LICENSE("GPL"); |