Commit | Line | Data |
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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> |
720b17e7 | 20 | #include <linux/pagemap.h> |
2cc45cf2 | 21 | #include <linux/dma-mapping.h> |
f39c1ab3 | 22 | #include <linux/sched.h> |
5a0e3ad6 | 23 | #include <linux/slab.h> |
2cc45cf2 MD |
24 | #include <media/videobuf-dma-contig.h> |
25 | ||
26 | struct videobuf_dma_contig_memory { | |
27 | u32 magic; | |
28 | void *vaddr; | |
29 | dma_addr_t dma_handle; | |
30 | unsigned long size; | |
720b17e7 | 31 | int is_userptr; |
2cc45cf2 MD |
32 | }; |
33 | ||
34 | #define MAGIC_DC_MEM 0x0733ac61 | |
c60f2b5c GL |
35 | #define MAGIC_CHECK(is, should) \ |
36 | if (unlikely((is) != (should))) { \ | |
37 | pr_err("magic mismatch: %x expected %x\n", (is), (should)); \ | |
38 | BUG(); \ | |
2cc45cf2 MD |
39 | } |
40 | ||
41 | static void | |
42 | videobuf_vm_open(struct vm_area_struct *vma) | |
43 | { | |
44 | struct videobuf_mapping *map = vma->vm_private_data; | |
45 | ||
46 | dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", | |
47 | map, map->count, vma->vm_start, vma->vm_end); | |
48 | ||
49 | map->count++; | |
50 | } | |
51 | ||
52 | static void videobuf_vm_close(struct vm_area_struct *vma) | |
53 | { | |
54 | struct videobuf_mapping *map = vma->vm_private_data; | |
55 | struct videobuf_queue *q = map->q; | |
56 | int i; | |
57 | ||
f35f1bb8 | 58 | dev_dbg(q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", |
2cc45cf2 MD |
59 | map, map->count, vma->vm_start, vma->vm_end); |
60 | ||
61 | map->count--; | |
62 | if (0 == map->count) { | |
63 | struct videobuf_dma_contig_memory *mem; | |
64 | ||
f35f1bb8 | 65 | dev_dbg(q->dev, "munmap %p q=%p\n", map, q); |
97397687 | 66 | videobuf_queue_lock(q); |
2cc45cf2 MD |
67 | |
68 | /* We need first to cancel streams, before unmapping */ | |
69 | if (q->streaming) | |
70 | videobuf_queue_cancel(q); | |
71 | ||
72 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { | |
73 | if (NULL == q->bufs[i]) | |
74 | continue; | |
75 | ||
76 | if (q->bufs[i]->map != map) | |
77 | continue; | |
78 | ||
79 | mem = q->bufs[i]->priv; | |
80 | if (mem) { | |
81 | /* This callback is called only if kernel has | |
82 | allocated memory and this memory is mmapped. | |
83 | In this case, memory should be freed, | |
84 | in order to do memory unmap. | |
85 | */ | |
86 | ||
87 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
88 | ||
89 | /* vfree is not atomic - can't be | |
90 | called with IRQ's disabled | |
91 | */ | |
f35f1bb8 | 92 | dev_dbg(q->dev, "buf[%d] freeing %p\n", |
2cc45cf2 MD |
93 | i, mem->vaddr); |
94 | ||
95 | dma_free_coherent(q->dev, mem->size, | |
96 | mem->vaddr, mem->dma_handle); | |
97 | mem->vaddr = NULL; | |
98 | } | |
99 | ||
100 | q->bufs[i]->map = NULL; | |
101 | q->bufs[i]->baddr = 0; | |
102 | } | |
103 | ||
104 | kfree(map); | |
105 | ||
97397687 | 106 | videobuf_queue_unlock(q); |
2cc45cf2 MD |
107 | } |
108 | } | |
109 | ||
f0f37e2f | 110 | static const struct vm_operations_struct videobuf_vm_ops = { |
2cc45cf2 MD |
111 | .open = videobuf_vm_open, |
112 | .close = videobuf_vm_close, | |
113 | }; | |
114 | ||
720b17e7 MD |
115 | /** |
116 | * videobuf_dma_contig_user_put() - reset pointer to user space buffer | |
117 | * @mem: per-buffer private videobuf-dma-contig data | |
118 | * | |
119 | * This function resets the user space pointer | |
120 | */ | |
121 | static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem) | |
122 | { | |
123 | mem->is_userptr = 0; | |
124 | mem->dma_handle = 0; | |
125 | mem->size = 0; | |
126 | } | |
127 | ||
128 | /** | |
129 | * videobuf_dma_contig_user_get() - setup user space memory pointer | |
130 | * @mem: per-buffer private videobuf-dma-contig data | |
131 | * @vb: video buffer to map | |
132 | * | |
133 | * This function validates and sets up a pointer to user space memory. | |
134 | * Only physically contiguous pfn-mapped memory is accepted. | |
135 | * | |
136 | * Returns 0 if successful. | |
137 | */ | |
138 | static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, | |
139 | struct videobuf_buffer *vb) | |
140 | { | |
141 | struct mm_struct *mm = current->mm; | |
142 | struct vm_area_struct *vma; | |
143 | unsigned long prev_pfn, this_pfn; | |
144 | unsigned long pages_done, user_address; | |
31bedfa5 | 145 | unsigned int offset; |
720b17e7 MD |
146 | int ret; |
147 | ||
31bedfa5 MK |
148 | offset = vb->baddr & ~PAGE_MASK; |
149 | mem->size = PAGE_ALIGN(vb->size + offset); | |
720b17e7 MD |
150 | mem->is_userptr = 0; |
151 | ret = -EINVAL; | |
152 | ||
153 | down_read(&mm->mmap_sem); | |
154 | ||
155 | vma = find_vma(mm, vb->baddr); | |
156 | if (!vma) | |
157 | goto out_up; | |
158 | ||
159 | if ((vb->baddr + mem->size) > vma->vm_end) | |
160 | goto out_up; | |
161 | ||
162 | pages_done = 0; | |
163 | prev_pfn = 0; /* kill warning */ | |
164 | user_address = vb->baddr; | |
165 | ||
166 | while (pages_done < (mem->size >> PAGE_SHIFT)) { | |
167 | ret = follow_pfn(vma, user_address, &this_pfn); | |
168 | if (ret) | |
169 | break; | |
170 | ||
171 | if (pages_done == 0) | |
31bedfa5 | 172 | mem->dma_handle = (this_pfn << PAGE_SHIFT) + offset; |
720b17e7 MD |
173 | else if (this_pfn != (prev_pfn + 1)) |
174 | ret = -EFAULT; | |
175 | ||
176 | if (ret) | |
177 | break; | |
178 | ||
179 | prev_pfn = this_pfn; | |
180 | user_address += PAGE_SIZE; | |
181 | pages_done++; | |
182 | } | |
183 | ||
184 | if (!ret) | |
185 | mem->is_userptr = 1; | |
186 | ||
187 | out_up: | |
188 | up_read(¤t->mm->mmap_sem); | |
189 | ||
190 | return ret; | |
191 | } | |
192 | ||
33c38283 | 193 | static struct videobuf_buffer *__videobuf_alloc_vb(size_t size) |
2cc45cf2 MD |
194 | { |
195 | struct videobuf_dma_contig_memory *mem; | |
196 | struct videobuf_buffer *vb; | |
197 | ||
198 | vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); | |
199 | if (vb) { | |
200 | mem = vb->priv = ((char *)vb) + size; | |
201 | mem->magic = MAGIC_DC_MEM; | |
202 | } | |
203 | ||
204 | return vb; | |
205 | } | |
206 | ||
037c75eb | 207 | static void *__videobuf_to_vaddr(struct videobuf_buffer *buf) |
2cc45cf2 MD |
208 | { |
209 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
210 | ||
211 | BUG_ON(!mem); | |
212 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
213 | ||
214 | return mem->vaddr; | |
215 | } | |
216 | ||
217 | static int __videobuf_iolock(struct videobuf_queue *q, | |
218 | struct videobuf_buffer *vb, | |
219 | struct v4l2_framebuffer *fbuf) | |
220 | { | |
221 | struct videobuf_dma_contig_memory *mem = vb->priv; | |
222 | ||
223 | BUG_ON(!mem); | |
224 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
225 | ||
226 | switch (vb->memory) { | |
227 | case V4L2_MEMORY_MMAP: | |
228 | dev_dbg(q->dev, "%s memory method MMAP\n", __func__); | |
229 | ||
230 | /* All handling should be done by __videobuf_mmap_mapper() */ | |
231 | if (!mem->vaddr) { | |
232 | dev_err(q->dev, "memory is not alloced/mmapped.\n"); | |
233 | return -EINVAL; | |
234 | } | |
235 | break; | |
236 | case V4L2_MEMORY_USERPTR: | |
237 | dev_dbg(q->dev, "%s memory method USERPTR\n", __func__); | |
238 | ||
720b17e7 | 239 | /* handle pointer from user space */ |
2cc45cf2 | 240 | if (vb->baddr) |
720b17e7 | 241 | return videobuf_dma_contig_user_get(mem, vb); |
2cc45cf2 | 242 | |
720b17e7 | 243 | /* allocate memory for the read() method */ |
2cc45cf2 MD |
244 | mem->size = PAGE_ALIGN(vb->size); |
245 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, | |
246 | &mem->dma_handle, GFP_KERNEL); | |
247 | if (!mem->vaddr) { | |
248 | dev_err(q->dev, "dma_alloc_coherent %ld failed\n", | |
249 | mem->size); | |
250 | return -ENOMEM; | |
251 | } | |
252 | ||
253 | dev_dbg(q->dev, "dma_alloc_coherent data is at %p (%ld)\n", | |
254 | mem->vaddr, mem->size); | |
255 | break; | |
256 | case V4L2_MEMORY_OVERLAY: | |
257 | default: | |
258 | dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n", | |
259 | __func__); | |
260 | return -EINVAL; | |
261 | } | |
262 | ||
263 | return 0; | |
264 | } | |
265 | ||
2cc45cf2 | 266 | static int __videobuf_mmap_mapper(struct videobuf_queue *q, |
0b62b737 | 267 | struct videobuf_buffer *buf, |
2cc45cf2 MD |
268 | struct vm_area_struct *vma) |
269 | { | |
270 | struct videobuf_dma_contig_memory *mem; | |
271 | struct videobuf_mapping *map; | |
2cc45cf2 | 272 | int retval; |
0b62b737 | 273 | unsigned long size; |
2cc45cf2 MD |
274 | |
275 | dev_dbg(q->dev, "%s\n", __func__); | |
2cc45cf2 MD |
276 | |
277 | /* create mapping + update buffer list */ | |
278 | map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); | |
279 | if (!map) | |
280 | return -ENOMEM; | |
281 | ||
0b62b737 | 282 | buf->map = map; |
2cc45cf2 MD |
283 | map->q = q; |
284 | ||
0b62b737 | 285 | buf->baddr = vma->vm_start; |
2cc45cf2 | 286 | |
0b62b737 | 287 | mem = buf->priv; |
2cc45cf2 MD |
288 | BUG_ON(!mem); |
289 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
290 | ||
0b62b737 | 291 | mem->size = PAGE_ALIGN(buf->bsize); |
2cc45cf2 MD |
292 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, |
293 | &mem->dma_handle, GFP_KERNEL); | |
294 | if (!mem->vaddr) { | |
295 | dev_err(q->dev, "dma_alloc_coherent size %ld failed\n", | |
296 | mem->size); | |
297 | goto error; | |
298 | } | |
299 | dev_dbg(q->dev, "dma_alloc_coherent data is at addr %p (size %ld)\n", | |
300 | mem->vaddr, mem->size); | |
301 | ||
302 | /* Try to remap memory */ | |
303 | ||
304 | size = vma->vm_end - vma->vm_start; | |
305 | size = (size < mem->size) ? size : mem->size; | |
306 | ||
307 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
308 | retval = remap_pfn_range(vma, vma->vm_start, | |
309 | mem->dma_handle >> PAGE_SHIFT, | |
310 | size, vma->vm_page_prot); | |
311 | if (retval) { | |
312 | dev_err(q->dev, "mmap: remap failed with error %d. ", retval); | |
313 | dma_free_coherent(q->dev, mem->size, | |
314 | mem->vaddr, mem->dma_handle); | |
315 | goto error; | |
316 | } | |
317 | ||
318 | vma->vm_ops = &videobuf_vm_ops; | |
319 | vma->vm_flags |= VM_DONTEXPAND; | |
320 | vma->vm_private_data = map; | |
321 | ||
322 | dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n", | |
323 | map, q, vma->vm_start, vma->vm_end, | |
0b62b737 HV |
324 | (long int)buf->bsize, |
325 | vma->vm_pgoff, buf->i); | |
2cc45cf2 MD |
326 | |
327 | videobuf_vm_open(vma); | |
328 | ||
329 | return 0; | |
330 | ||
331 | error: | |
332 | kfree(map); | |
333 | return -ENOMEM; | |
334 | } | |
335 | ||
2cc45cf2 MD |
336 | static struct videobuf_qtype_ops qops = { |
337 | .magic = MAGIC_QTYPE_OPS, | |
338 | ||
33c38283 | 339 | .alloc_vb = __videobuf_alloc_vb, |
2cc45cf2 | 340 | .iolock = __videobuf_iolock, |
2cc45cf2 | 341 | .mmap_mapper = __videobuf_mmap_mapper, |
037c75eb | 342 | .vaddr = __videobuf_to_vaddr, |
2cc45cf2 MD |
343 | }; |
344 | ||
345 | void videobuf_queue_dma_contig_init(struct videobuf_queue *q, | |
38a54f35 | 346 | const struct videobuf_queue_ops *ops, |
2cc45cf2 MD |
347 | struct device *dev, |
348 | spinlock_t *irqlock, | |
349 | enum v4l2_buf_type type, | |
350 | enum v4l2_field field, | |
351 | unsigned int msize, | |
352 | void *priv) | |
353 | { | |
354 | videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, | |
355 | priv, &qops); | |
356 | } | |
357 | EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init); | |
358 | ||
359 | dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf) | |
360 | { | |
361 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
362 | ||
363 | BUG_ON(!mem); | |
364 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
365 | ||
366 | return mem->dma_handle; | |
367 | } | |
368 | EXPORT_SYMBOL_GPL(videobuf_to_dma_contig); | |
369 | ||
370 | void videobuf_dma_contig_free(struct videobuf_queue *q, | |
371 | struct videobuf_buffer *buf) | |
372 | { | |
373 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
374 | ||
375 | /* mmapped memory can't be freed here, otherwise mmapped region | |
376 | would be released, while still needed. In this case, the memory | |
377 | release should happen inside videobuf_vm_close(). | |
378 | So, it should free memory only if the memory were allocated for | |
379 | read() operation. | |
380 | */ | |
720b17e7 | 381 | if (buf->memory != V4L2_MEMORY_USERPTR) |
2cc45cf2 MD |
382 | return; |
383 | ||
384 | if (!mem) | |
385 | return; | |
386 | ||
387 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
388 | ||
720b17e7 MD |
389 | /* handle user space pointer case */ |
390 | if (buf->baddr) { | |
391 | videobuf_dma_contig_user_put(mem); | |
392 | return; | |
393 | } | |
394 | ||
395 | /* read() method */ | |
b2b476f5 PO |
396 | if (mem->vaddr) { |
397 | dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle); | |
398 | mem->vaddr = NULL; | |
399 | } | |
2cc45cf2 MD |
400 | } |
401 | EXPORT_SYMBOL_GPL(videobuf_dma_contig_free); | |
402 | ||
403 | MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers"); | |
404 | MODULE_AUTHOR("Magnus Damm"); | |
405 | MODULE_LICENSE("GPL"); |