Commit | Line | Data |
---|---|---|
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; | |
31 | }; | |
32 | ||
33 | #define MAGIC_DC_MEM 0x0733ac61 | |
c60f2b5c GL |
34 | #define MAGIC_CHECK(is, should) \ |
35 | if (unlikely((is) != (should))) { \ | |
36 | pr_err("magic mismatch: %x expected %x\n", (is), (should)); \ | |
37 | BUG(); \ | |
2cc45cf2 MD |
38 | } |
39 | ||
a8f3c203 FV |
40 | static int __videobuf_dc_alloc(struct device *dev, |
41 | struct videobuf_dma_contig_memory *mem, | |
50fbe32c | 42 | unsigned long size, gfp_t flags) |
a8f3c203 FV |
43 | { |
44 | mem->size = size; | |
cb132cd5 MCC |
45 | mem->vaddr = dma_alloc_coherent(dev, mem->size, |
46 | &mem->dma_handle, flags); | |
a8f3c203 FV |
47 | |
48 | if (!mem->vaddr) { | |
49 | dev_err(dev, "memory alloc size %ld failed\n", mem->size); | |
50 | return -ENOMEM; | |
51 | } | |
52 | ||
53 | dev_dbg(dev, "dma mapped data is at %p (%ld)\n", mem->vaddr, mem->size); | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | static void __videobuf_dc_free(struct device *dev, | |
59 | struct videobuf_dma_contig_memory *mem) | |
60 | { | |
cb132cd5 | 61 | dma_free_coherent(dev, mem->size, mem->vaddr, mem->dma_handle); |
a8f3c203 FV |
62 | |
63 | mem->vaddr = NULL; | |
64 | } | |
65 | ||
66 | static void videobuf_vm_open(struct vm_area_struct *vma) | |
2cc45cf2 MD |
67 | { |
68 | struct videobuf_mapping *map = vma->vm_private_data; | |
69 | ||
cca36e2e | 70 | dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", |
2cc45cf2 MD |
71 | map, map->count, vma->vm_start, vma->vm_end); |
72 | ||
73 | map->count++; | |
74 | } | |
75 | ||
76 | static void videobuf_vm_close(struct vm_area_struct *vma) | |
77 | { | |
78 | struct videobuf_mapping *map = vma->vm_private_data; | |
79 | struct videobuf_queue *q = map->q; | |
80 | int i; | |
81 | ||
f35f1bb8 | 82 | dev_dbg(q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", |
2cc45cf2 MD |
83 | map, map->count, vma->vm_start, vma->vm_end); |
84 | ||
cca36e2e HV |
85 | map->count--; |
86 | if (0 == map->count) { | |
2cc45cf2 MD |
87 | struct videobuf_dma_contig_memory *mem; |
88 | ||
f35f1bb8 | 89 | dev_dbg(q->dev, "munmap %p q=%p\n", map, q); |
cca36e2e | 90 | videobuf_queue_lock(q); |
2cc45cf2 MD |
91 | |
92 | /* We need first to cancel streams, before unmapping */ | |
93 | if (q->streaming) | |
94 | videobuf_queue_cancel(q); | |
95 | ||
96 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { | |
97 | if (NULL == q->bufs[i]) | |
98 | continue; | |
99 | ||
100 | if (q->bufs[i]->map != map) | |
101 | continue; | |
102 | ||
103 | mem = q->bufs[i]->priv; | |
104 | if (mem) { | |
105 | /* This callback is called only if kernel has | |
106 | allocated memory and this memory is mmapped. | |
107 | In this case, memory should be freed, | |
108 | in order to do memory unmap. | |
109 | */ | |
110 | ||
111 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
112 | ||
113 | /* vfree is not atomic - can't be | |
114 | called with IRQ's disabled | |
115 | */ | |
f35f1bb8 | 116 | dev_dbg(q->dev, "buf[%d] freeing %p\n", |
2cc45cf2 MD |
117 | i, mem->vaddr); |
118 | ||
a8f3c203 | 119 | __videobuf_dc_free(q->dev, mem); |
2cc45cf2 MD |
120 | mem->vaddr = NULL; |
121 | } | |
122 | ||
a8f3c203 | 123 | q->bufs[i]->map = NULL; |
2cc45cf2 MD |
124 | q->bufs[i]->baddr = 0; |
125 | } | |
126 | ||
127 | kfree(map); | |
128 | ||
cca36e2e | 129 | videobuf_queue_unlock(q); |
2cc45cf2 MD |
130 | } |
131 | } | |
132 | ||
f0f37e2f | 133 | static const struct vm_operations_struct videobuf_vm_ops = { |
a8f3c203 FV |
134 | .open = videobuf_vm_open, |
135 | .close = videobuf_vm_close, | |
2cc45cf2 MD |
136 | }; |
137 | ||
720b17e7 MD |
138 | /** |
139 | * videobuf_dma_contig_user_put() - reset pointer to user space buffer | |
140 | * @mem: per-buffer private videobuf-dma-contig data | |
141 | * | |
142 | * This function resets the user space pointer | |
143 | */ | |
144 | static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem) | |
145 | { | |
720b17e7 MD |
146 | mem->dma_handle = 0; |
147 | mem->size = 0; | |
148 | } | |
149 | ||
150 | /** | |
151 | * videobuf_dma_contig_user_get() - setup user space memory pointer | |
152 | * @mem: per-buffer private videobuf-dma-contig data | |
153 | * @vb: video buffer to map | |
154 | * | |
155 | * This function validates and sets up a pointer to user space memory. | |
156 | * Only physically contiguous pfn-mapped memory is accepted. | |
157 | * | |
158 | * Returns 0 if successful. | |
159 | */ | |
160 | static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, | |
161 | struct videobuf_buffer *vb) | |
162 | { | |
163 | struct mm_struct *mm = current->mm; | |
164 | struct vm_area_struct *vma; | |
165 | unsigned long prev_pfn, this_pfn; | |
166 | unsigned long pages_done, user_address; | |
31bedfa5 | 167 | unsigned int offset; |
720b17e7 MD |
168 | int ret; |
169 | ||
31bedfa5 MK |
170 | offset = vb->baddr & ~PAGE_MASK; |
171 | mem->size = PAGE_ALIGN(vb->size + offset); | |
720b17e7 MD |
172 | ret = -EINVAL; |
173 | ||
174 | down_read(&mm->mmap_sem); | |
175 | ||
176 | vma = find_vma(mm, vb->baddr); | |
177 | if (!vma) | |
178 | goto out_up; | |
179 | ||
180 | if ((vb->baddr + mem->size) > vma->vm_end) | |
181 | goto out_up; | |
182 | ||
183 | pages_done = 0; | |
184 | prev_pfn = 0; /* kill warning */ | |
185 | user_address = vb->baddr; | |
186 | ||
187 | while (pages_done < (mem->size >> PAGE_SHIFT)) { | |
188 | ret = follow_pfn(vma, user_address, &this_pfn); | |
189 | if (ret) | |
190 | break; | |
191 | ||
192 | if (pages_done == 0) | |
31bedfa5 | 193 | mem->dma_handle = (this_pfn << PAGE_SHIFT) + offset; |
720b17e7 MD |
194 | else if (this_pfn != (prev_pfn + 1)) |
195 | ret = -EFAULT; | |
196 | ||
197 | if (ret) | |
198 | break; | |
199 | ||
200 | prev_pfn = this_pfn; | |
201 | user_address += PAGE_SIZE; | |
202 | pages_done++; | |
203 | } | |
204 | ||
a8f3c203 | 205 | out_up: |
720b17e7 MD |
206 | up_read(¤t->mm->mmap_sem); |
207 | ||
208 | return ret; | |
209 | } | |
210 | ||
cb132cd5 | 211 | static struct videobuf_buffer *__videobuf_alloc(size_t size) |
2cc45cf2 MD |
212 | { |
213 | struct videobuf_dma_contig_memory *mem; | |
214 | struct videobuf_buffer *vb; | |
215 | ||
216 | vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); | |
217 | if (vb) { | |
a8f3c203 FV |
218 | vb->priv = ((char *)vb) + size; |
219 | mem = vb->priv; | |
2cc45cf2 MD |
220 | mem->magic = MAGIC_DC_MEM; |
221 | } | |
222 | ||
223 | return vb; | |
224 | } | |
225 | ||
037c75eb | 226 | static void *__videobuf_to_vaddr(struct videobuf_buffer *buf) |
2cc45cf2 MD |
227 | { |
228 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
229 | ||
230 | BUG_ON(!mem); | |
231 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
232 | ||
233 | return mem->vaddr; | |
234 | } | |
235 | ||
236 | static int __videobuf_iolock(struct videobuf_queue *q, | |
237 | struct videobuf_buffer *vb, | |
238 | struct v4l2_framebuffer *fbuf) | |
239 | { | |
240 | struct videobuf_dma_contig_memory *mem = vb->priv; | |
241 | ||
242 | BUG_ON(!mem); | |
243 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
244 | ||
245 | switch (vb->memory) { | |
246 | case V4L2_MEMORY_MMAP: | |
247 | dev_dbg(q->dev, "%s memory method MMAP\n", __func__); | |
248 | ||
249 | /* All handling should be done by __videobuf_mmap_mapper() */ | |
250 | if (!mem->vaddr) { | |
251 | dev_err(q->dev, "memory is not alloced/mmapped.\n"); | |
252 | return -EINVAL; | |
253 | } | |
254 | break; | |
255 | case V4L2_MEMORY_USERPTR: | |
256 | dev_dbg(q->dev, "%s memory method USERPTR\n", __func__); | |
257 | ||
720b17e7 | 258 | /* handle pointer from user space */ |
2cc45cf2 | 259 | if (vb->baddr) |
720b17e7 | 260 | return videobuf_dma_contig_user_get(mem, vb); |
2cc45cf2 | 261 | |
720b17e7 | 262 | /* allocate memory for the read() method */ |
a8f3c203 FV |
263 | if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(vb->size), |
264 | GFP_KERNEL)) | |
2cc45cf2 | 265 | return -ENOMEM; |
2cc45cf2 MD |
266 | break; |
267 | case V4L2_MEMORY_OVERLAY: | |
268 | default: | |
a8f3c203 | 269 | dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n", __func__); |
2cc45cf2 MD |
270 | return -EINVAL; |
271 | } | |
272 | ||
273 | return 0; | |
274 | } | |
275 | ||
2cc45cf2 | 276 | static int __videobuf_mmap_mapper(struct videobuf_queue *q, |
0b62b737 | 277 | struct videobuf_buffer *buf, |
2cc45cf2 MD |
278 | struct vm_area_struct *vma) |
279 | { | |
280 | struct videobuf_dma_contig_memory *mem; | |
281 | struct videobuf_mapping *map; | |
2cc45cf2 | 282 | int retval; |
0b62b737 | 283 | unsigned long size; |
2cc45cf2 MD |
284 | |
285 | dev_dbg(q->dev, "%s\n", __func__); | |
2cc45cf2 MD |
286 | |
287 | /* create mapping + update buffer list */ | |
288 | map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); | |
289 | if (!map) | |
290 | return -ENOMEM; | |
291 | ||
0b62b737 | 292 | buf->map = map; |
2cc45cf2 MD |
293 | map->q = q; |
294 | ||
0b62b737 | 295 | buf->baddr = vma->vm_start; |
2cc45cf2 | 296 | |
0b62b737 | 297 | mem = buf->priv; |
2cc45cf2 MD |
298 | BUG_ON(!mem); |
299 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
300 | ||
a8f3c203 FV |
301 | if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(buf->bsize), |
302 | GFP_KERNEL | __GFP_COMP)) | |
2cc45cf2 | 303 | goto error; |
2cc45cf2 MD |
304 | |
305 | /* Try to remap memory */ | |
2cc45cf2 | 306 | size = vma->vm_end - vma->vm_start; |
cb132cd5 | 307 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
8a6a547f FF |
308 | |
309 | /* the "vm_pgoff" is just used in v4l2 to find the | |
310 | * corresponding buffer data structure which is allocated | |
311 | * earlier and it does not mean the offset from the physical | |
312 | * buffer start address as usual. So set it to 0 to pass | |
313 | * the sanity check in vm_iomap_memory(). | |
314 | */ | |
315 | vma->vm_pgoff = 0; | |
316 | ||
29f1cdb0 | 317 | retval = vm_iomap_memory(vma, mem->dma_handle, size); |
cb132cd5 MCC |
318 | if (retval) { |
319 | dev_err(q->dev, "mmap: remap failed with error %d. ", | |
320 | retval); | |
321 | dma_free_coherent(q->dev, mem->size, | |
322 | mem->vaddr, mem->dma_handle); | |
323 | goto error; | |
2cc45cf2 MD |
324 | } |
325 | ||
a8f3c203 FV |
326 | vma->vm_ops = &videobuf_vm_ops; |
327 | vma->vm_flags |= VM_DONTEXPAND; | |
2cc45cf2 MD |
328 | vma->vm_private_data = map; |
329 | ||
330 | dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n", | |
331 | map, q, vma->vm_start, vma->vm_end, | |
a8f3c203 | 332 | (long int)buf->bsize, vma->vm_pgoff, buf->i); |
2cc45cf2 MD |
333 | |
334 | videobuf_vm_open(vma); | |
335 | ||
336 | return 0; | |
337 | ||
338 | error: | |
339 | kfree(map); | |
340 | return -ENOMEM; | |
341 | } | |
342 | ||
2cc45cf2 | 343 | static struct videobuf_qtype_ops qops = { |
a8f3c203 | 344 | .magic = MAGIC_QTYPE_OPS, |
cb132cd5 | 345 | .alloc_vb = __videobuf_alloc, |
a8f3c203 | 346 | .iolock = __videobuf_iolock, |
a8f3c203 FV |
347 | .mmap_mapper = __videobuf_mmap_mapper, |
348 | .vaddr = __videobuf_to_vaddr, | |
2cc45cf2 MD |
349 | }; |
350 | ||
351 | void videobuf_queue_dma_contig_init(struct videobuf_queue *q, | |
38a54f35 | 352 | const struct videobuf_queue_ops *ops, |
2cc45cf2 MD |
353 | struct device *dev, |
354 | spinlock_t *irqlock, | |
355 | enum v4l2_buf_type type, | |
356 | enum v4l2_field field, | |
357 | unsigned int msize, | |
08bff03e HV |
358 | void *priv, |
359 | struct mutex *ext_lock) | |
2cc45cf2 MD |
360 | { |
361 | videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, | |
08bff03e | 362 | priv, &qops, ext_lock); |
2cc45cf2 MD |
363 | } |
364 | EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init); | |
365 | ||
366 | dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf) | |
367 | { | |
368 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
369 | ||
370 | BUG_ON(!mem); | |
371 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
372 | ||
373 | return mem->dma_handle; | |
374 | } | |
375 | EXPORT_SYMBOL_GPL(videobuf_to_dma_contig); | |
376 | ||
377 | void videobuf_dma_contig_free(struct videobuf_queue *q, | |
378 | struct videobuf_buffer *buf) | |
379 | { | |
380 | struct videobuf_dma_contig_memory *mem = buf->priv; | |
381 | ||
382 | /* mmapped memory can't be freed here, otherwise mmapped region | |
383 | would be released, while still needed. In this case, the memory | |
384 | release should happen inside videobuf_vm_close(). | |
385 | So, it should free memory only if the memory were allocated for | |
386 | read() operation. | |
387 | */ | |
720b17e7 | 388 | if (buf->memory != V4L2_MEMORY_USERPTR) |
2cc45cf2 MD |
389 | return; |
390 | ||
391 | if (!mem) | |
392 | return; | |
393 | ||
394 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); | |
395 | ||
720b17e7 MD |
396 | /* handle user space pointer case */ |
397 | if (buf->baddr) { | |
398 | videobuf_dma_contig_user_put(mem); | |
399 | return; | |
400 | } | |
401 | ||
402 | /* read() method */ | |
b2b476f5 | 403 | if (mem->vaddr) { |
a8f3c203 | 404 | __videobuf_dc_free(q->dev, mem); |
b2b476f5 PO |
405 | mem->vaddr = NULL; |
406 | } | |
2cc45cf2 MD |
407 | } |
408 | EXPORT_SYMBOL_GPL(videobuf_dma_contig_free); | |
409 | ||
410 | MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers"); | |
411 | MODULE_AUTHOR("Magnus Damm"); | |
412 | MODULE_LICENSE("GPL"); |