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2cc45cf2 MD |
1 | /* |
2 | * helper functions for physically contiguous capture buffers | |
3 | * | |
4 | * The functions support hardware lacking scatter gather support | |
5 | * (i.e. the buffers must be linear in physical memory) | |
6 | * | |
7 | * Copyright (c) 2008 Magnus Damm | |
8 | * | |
9 | * Based on videobuf-vmalloc.c, | |
10 | * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org> | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2 | |
15 | */ | |
16 | ||
17 | #include <linux/init.h> | |
18 | #include <linux/module.h> | |
f19ad390 | 19 | #include <linux/mm.h> |
2cc45cf2 MD |
20 | #include <linux/dma-mapping.h> |
21 | #include <media/videobuf-dma-contig.h> | |
22 | ||
23 | struct videobuf_dma_contig_memory { | |
24 | u32 magic; | |
25 | void *vaddr; | |
26 | dma_addr_t dma_handle; | |
27 | unsigned long size; | |
28 | }; | |
29 | ||
30 | #define MAGIC_DC_MEM 0x0733ac61 | |
31 | #define MAGIC_CHECK(is, should) \ | |
32 | if (unlikely((is) != (should))) { \ | |
33 | pr_err("magic mismatch: %x expected %x\n", is, should); \ | |
34 | BUG(); \ | |
35 | } | |
36 | ||
37 | static void | |
38 | videobuf_vm_open(struct vm_area_struct *vma) | |
39 | { | |
40 | struct videobuf_mapping *map = vma->vm_private_data; | |
41 | ||
42 | dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", | |
43 | map, map->count, vma->vm_start, vma->vm_end); | |
44 | ||
45 | map->count++; | |
46 | } | |
47 | ||
48 | static void videobuf_vm_close(struct vm_area_struct *vma) | |
49 | { | |
50 | struct videobuf_mapping *map = vma->vm_private_data; | |
51 | struct videobuf_queue *q = map->q; | |
52 | int i; | |
53 | ||
54 | dev_dbg(map->q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", | |
55 | map, map->count, vma->vm_start, vma->vm_end); | |
56 | ||
57 | map->count--; | |
58 | if (0 == map->count) { | |
59 | struct videobuf_dma_contig_memory *mem; | |
60 | ||
61 | dev_dbg(map->q->dev, "munmap %p q=%p\n", map, q); | |
62 | mutex_lock(&q->vb_lock); | |
63 | ||
64 | /* We need first to cancel streams, before unmapping */ | |
65 | if (q->streaming) | |
66 | videobuf_queue_cancel(q); | |
67 | ||
68 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { | |
69 | if (NULL == q->bufs[i]) | |
70 | continue; | |
71 | ||
72 | if (q->bufs[i]->map != map) | |
73 | continue; | |
74 | ||
75 | mem = q->bufs[i]->priv; | |
76 | if (mem) { | |
77 | /* This callback is called only if kernel has | |
78 | allocated memory and this memory is mmapped. | |
79 | In this case, memory should be freed, | |
80 | in order to do memory unmap. | |
81 | */ | |
82 | ||
83 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
84 | ||
85 | /* vfree is not atomic - can't be | |
86 | called with IRQ's disabled | |
87 | */ | |
88 | dev_dbg(map->q->dev, "buf[%d] freeing %p\n", | |
89 | i, mem->vaddr); | |
90 | ||
91 | dma_free_coherent(q->dev, mem->size, | |
92 | mem->vaddr, mem->dma_handle); | |
93 | mem->vaddr = NULL; | |
94 | } | |
95 | ||
96 | q->bufs[i]->map = NULL; | |
97 | q->bufs[i]->baddr = 0; | |
98 | } | |
99 | ||
100 | kfree(map); | |
101 | ||
102 | mutex_unlock(&q->vb_lock); | |
103 | } | |
104 | } | |
105 | ||
106 | static struct vm_operations_struct videobuf_vm_ops = { | |
107 | .open = videobuf_vm_open, | |
108 | .close = videobuf_vm_close, | |
109 | }; | |
110 | ||
111 | static void *__videobuf_alloc(size_t size) | |
112 | { | |
113 | struct videobuf_dma_contig_memory *mem; | |
114 | struct videobuf_buffer *vb; | |
115 | ||
116 | vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); | |
117 | if (vb) { | |
118 | mem = vb->priv = ((char *)vb) + size; | |
119 | mem->magic = MAGIC_DC_MEM; | |
120 | } | |
121 | ||
122 | return vb; | |
123 | } | |
124 | ||
125 | static void *__videobuf_to_vmalloc(struct videobuf_buffer *buf) | |
126 | { | |
127 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
128 | ||
129 | BUG_ON(!mem); | |
130 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
131 | ||
132 | return mem->vaddr; | |
133 | } | |
134 | ||
135 | static int __videobuf_iolock(struct videobuf_queue *q, | |
136 | struct videobuf_buffer *vb, | |
137 | struct v4l2_framebuffer *fbuf) | |
138 | { | |
139 | struct videobuf_dma_contig_memory *mem = vb->priv; | |
140 | ||
141 | BUG_ON(!mem); | |
142 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
143 | ||
144 | switch (vb->memory) { | |
145 | case V4L2_MEMORY_MMAP: | |
146 | dev_dbg(q->dev, "%s memory method MMAP\n", __func__); | |
147 | ||
148 | /* All handling should be done by __videobuf_mmap_mapper() */ | |
149 | if (!mem->vaddr) { | |
150 | dev_err(q->dev, "memory is not alloced/mmapped.\n"); | |
151 | return -EINVAL; | |
152 | } | |
153 | break; | |
154 | case V4L2_MEMORY_USERPTR: | |
155 | dev_dbg(q->dev, "%s memory method USERPTR\n", __func__); | |
156 | ||
157 | /* The only USERPTR currently supported is the one needed for | |
158 | read() method. | |
159 | */ | |
160 | if (vb->baddr) | |
161 | return -EINVAL; | |
162 | ||
163 | mem->size = PAGE_ALIGN(vb->size); | |
164 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, | |
165 | &mem->dma_handle, GFP_KERNEL); | |
166 | if (!mem->vaddr) { | |
167 | dev_err(q->dev, "dma_alloc_coherent %ld failed\n", | |
168 | mem->size); | |
169 | return -ENOMEM; | |
170 | } | |
171 | ||
172 | dev_dbg(q->dev, "dma_alloc_coherent data is at %p (%ld)\n", | |
173 | mem->vaddr, mem->size); | |
174 | break; | |
175 | case V4L2_MEMORY_OVERLAY: | |
176 | default: | |
177 | dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n", | |
178 | __func__); | |
179 | return -EINVAL; | |
180 | } | |
181 | ||
182 | return 0; | |
183 | } | |
184 | ||
185 | static int __videobuf_sync(struct videobuf_queue *q, | |
186 | struct videobuf_buffer *buf) | |
187 | { | |
188 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
189 | ||
190 | BUG_ON(!mem); | |
191 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
192 | ||
193 | dma_sync_single_for_cpu(q->dev, mem->dma_handle, mem->size, | |
194 | DMA_FROM_DEVICE); | |
195 | return 0; | |
196 | } | |
197 | ||
198 | static int __videobuf_mmap_free(struct videobuf_queue *q) | |
199 | { | |
200 | unsigned int i; | |
201 | ||
202 | dev_dbg(q->dev, "%s\n", __func__); | |
203 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { | |
204 | if (q->bufs[i] && q->bufs[i]->map) | |
205 | return -EBUSY; | |
206 | } | |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
211 | static int __videobuf_mmap_mapper(struct videobuf_queue *q, | |
212 | struct vm_area_struct *vma) | |
213 | { | |
214 | struct videobuf_dma_contig_memory *mem; | |
215 | struct videobuf_mapping *map; | |
216 | unsigned int first; | |
217 | int retval; | |
218 | unsigned long size, offset = vma->vm_pgoff << PAGE_SHIFT; | |
219 | ||
220 | dev_dbg(q->dev, "%s\n", __func__); | |
221 | if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) | |
222 | return -EINVAL; | |
223 | ||
224 | /* look for first buffer to map */ | |
225 | for (first = 0; first < VIDEO_MAX_FRAME; first++) { | |
226 | if (!q->bufs[first]) | |
227 | continue; | |
228 | ||
229 | if (V4L2_MEMORY_MMAP != q->bufs[first]->memory) | |
230 | continue; | |
231 | if (q->bufs[first]->boff == offset) | |
232 | break; | |
233 | } | |
234 | if (VIDEO_MAX_FRAME == first) { | |
235 | dev_dbg(q->dev, "invalid user space offset [offset=0x%lx]\n", | |
236 | offset); | |
237 | return -EINVAL; | |
238 | } | |
239 | ||
240 | /* create mapping + update buffer list */ | |
241 | map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); | |
242 | if (!map) | |
243 | return -ENOMEM; | |
244 | ||
245 | q->bufs[first]->map = map; | |
246 | map->start = vma->vm_start; | |
247 | map->end = vma->vm_end; | |
248 | map->q = q; | |
249 | ||
250 | q->bufs[first]->baddr = vma->vm_start; | |
251 | ||
252 | mem = q->bufs[first]->priv; | |
253 | BUG_ON(!mem); | |
254 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
255 | ||
256 | mem->size = PAGE_ALIGN(q->bufs[first]->bsize); | |
257 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, | |
258 | &mem->dma_handle, GFP_KERNEL); | |
259 | if (!mem->vaddr) { | |
260 | dev_err(q->dev, "dma_alloc_coherent size %ld failed\n", | |
261 | mem->size); | |
262 | goto error; | |
263 | } | |
264 | dev_dbg(q->dev, "dma_alloc_coherent data is at addr %p (size %ld)\n", | |
265 | mem->vaddr, mem->size); | |
266 | ||
267 | /* Try to remap memory */ | |
268 | ||
269 | size = vma->vm_end - vma->vm_start; | |
270 | size = (size < mem->size) ? size : mem->size; | |
271 | ||
272 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
273 | retval = remap_pfn_range(vma, vma->vm_start, | |
274 | mem->dma_handle >> PAGE_SHIFT, | |
275 | size, vma->vm_page_prot); | |
276 | if (retval) { | |
277 | dev_err(q->dev, "mmap: remap failed with error %d. ", retval); | |
278 | dma_free_coherent(q->dev, mem->size, | |
279 | mem->vaddr, mem->dma_handle); | |
280 | goto error; | |
281 | } | |
282 | ||
283 | vma->vm_ops = &videobuf_vm_ops; | |
284 | vma->vm_flags |= VM_DONTEXPAND; | |
285 | vma->vm_private_data = map; | |
286 | ||
287 | dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n", | |
288 | map, q, vma->vm_start, vma->vm_end, | |
289 | (long int) q->bufs[first]->bsize, | |
290 | vma->vm_pgoff, first); | |
291 | ||
292 | videobuf_vm_open(vma); | |
293 | ||
294 | return 0; | |
295 | ||
296 | error: | |
297 | kfree(map); | |
298 | return -ENOMEM; | |
299 | } | |
300 | ||
301 | static int __videobuf_copy_to_user(struct videobuf_queue *q, | |
302 | char __user *data, size_t count, | |
303 | int nonblocking) | |
304 | { | |
305 | struct videobuf_dma_contig_memory *mem = q->read_buf->priv; | |
306 | void *vaddr; | |
307 | ||
308 | BUG_ON(!mem); | |
309 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
310 | BUG_ON(!mem->vaddr); | |
311 | ||
312 | /* copy to userspace */ | |
313 | if (count > q->read_buf->size - q->read_off) | |
314 | count = q->read_buf->size - q->read_off; | |
315 | ||
316 | vaddr = mem->vaddr; | |
317 | ||
318 | if (copy_to_user(data, vaddr + q->read_off, count)) | |
319 | return -EFAULT; | |
320 | ||
321 | return count; | |
322 | } | |
323 | ||
324 | static int __videobuf_copy_stream(struct videobuf_queue *q, | |
325 | char __user *data, size_t count, size_t pos, | |
326 | int vbihack, int nonblocking) | |
327 | { | |
328 | unsigned int *fc; | |
329 | struct videobuf_dma_contig_memory *mem = q->read_buf->priv; | |
330 | ||
331 | BUG_ON(!mem); | |
332 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
333 | ||
334 | if (vbihack) { | |
335 | /* dirty, undocumented hack -- pass the frame counter | |
336 | * within the last four bytes of each vbi data block. | |
337 | * We need that one to maintain backward compatibility | |
338 | * to all vbi decoding software out there ... */ | |
339 | fc = (unsigned int *)mem->vaddr; | |
340 | fc += (q->read_buf->size >> 2) - 1; | |
341 | *fc = q->read_buf->field_count >> 1; | |
342 | dev_dbg(q->dev, "vbihack: %d\n", *fc); | |
343 | } | |
344 | ||
345 | /* copy stuff using the common method */ | |
346 | count = __videobuf_copy_to_user(q, data, count, nonblocking); | |
347 | ||
348 | if ((count == -EFAULT) && (pos == 0)) | |
349 | return -EFAULT; | |
350 | ||
351 | return count; | |
352 | } | |
353 | ||
354 | static struct videobuf_qtype_ops qops = { | |
355 | .magic = MAGIC_QTYPE_OPS, | |
356 | ||
357 | .alloc = __videobuf_alloc, | |
358 | .iolock = __videobuf_iolock, | |
359 | .sync = __videobuf_sync, | |
360 | .mmap_free = __videobuf_mmap_free, | |
361 | .mmap_mapper = __videobuf_mmap_mapper, | |
362 | .video_copy_to_user = __videobuf_copy_to_user, | |
363 | .copy_stream = __videobuf_copy_stream, | |
364 | .vmalloc = __videobuf_to_vmalloc, | |
365 | }; | |
366 | ||
367 | void videobuf_queue_dma_contig_init(struct videobuf_queue *q, | |
368 | struct videobuf_queue_ops *ops, | |
369 | struct device *dev, | |
370 | spinlock_t *irqlock, | |
371 | enum v4l2_buf_type type, | |
372 | enum v4l2_field field, | |
373 | unsigned int msize, | |
374 | void *priv) | |
375 | { | |
376 | videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, | |
377 | priv, &qops); | |
378 | } | |
379 | EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init); | |
380 | ||
381 | dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf) | |
382 | { | |
383 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
384 | ||
385 | BUG_ON(!mem); | |
386 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
387 | ||
388 | return mem->dma_handle; | |
389 | } | |
390 | EXPORT_SYMBOL_GPL(videobuf_to_dma_contig); | |
391 | ||
392 | void videobuf_dma_contig_free(struct videobuf_queue *q, | |
393 | struct videobuf_buffer *buf) | |
394 | { | |
395 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
396 | ||
397 | /* mmapped memory can't be freed here, otherwise mmapped region | |
398 | would be released, while still needed. In this case, the memory | |
399 | release should happen inside videobuf_vm_close(). | |
400 | So, it should free memory only if the memory were allocated for | |
401 | read() operation. | |
402 | */ | |
403 | if ((buf->memory != V4L2_MEMORY_USERPTR) || !buf->baddr) | |
404 | return; | |
405 | ||
406 | if (!mem) | |
407 | return; | |
408 | ||
409 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
410 | ||
411 | dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle); | |
412 | mem->vaddr = NULL; | |
413 | } | |
414 | EXPORT_SYMBOL_GPL(videobuf_dma_contig_free); | |
415 | ||
416 | MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers"); | |
417 | MODULE_AUTHOR("Magnus Damm"); | |
418 | MODULE_LICENSE("GPL"); |