Merge branch 'master' into next
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / media / video / videobuf-dma-contig.c
CommitLineData
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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>
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24#include <media/videobuf-dma-contig.h>
25
26struct 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
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34#define MAGIC_CHECK(is, should) \
35 if (unlikely((is) != (should))) { \
36 pr_err("magic mismatch: %x expected %x\n", (is), (should)); \
37 BUG(); \
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38 }
39
40static void
41videobuf_vm_open(struct vm_area_struct *vma)
42{
43 struct videobuf_mapping *map = vma->vm_private_data;
44
45 dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n",
46 map, map->count, vma->vm_start, vma->vm_end);
47
48 map->count++;
49}
50
51static void videobuf_vm_close(struct vm_area_struct *vma)
52{
53 struct videobuf_mapping *map = vma->vm_private_data;
54 struct videobuf_queue *q = map->q;
55 int i;
56
f35f1bb8 57 dev_dbg(q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n",
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58 map, map->count, vma->vm_start, vma->vm_end);
59
60 map->count--;
61 if (0 == map->count) {
62 struct videobuf_dma_contig_memory *mem;
63
f35f1bb8 64 dev_dbg(q->dev, "munmap %p q=%p\n", map, q);
97397687 65 videobuf_queue_lock(q);
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66
67 /* We need first to cancel streams, before unmapping */
68 if (q->streaming)
69 videobuf_queue_cancel(q);
70
71 for (i = 0; i < VIDEO_MAX_FRAME; i++) {
72 if (NULL == q->bufs[i])
73 continue;
74
75 if (q->bufs[i]->map != map)
76 continue;
77
78 mem = q->bufs[i]->priv;
79 if (mem) {
80 /* This callback is called only if kernel has
81 allocated memory and this memory is mmapped.
82 In this case, memory should be freed,
83 in order to do memory unmap.
84 */
85
86 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
87
88 /* vfree is not atomic - can't be
89 called with IRQ's disabled
90 */
f35f1bb8 91 dev_dbg(q->dev, "buf[%d] freeing %p\n",
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92 i, mem->vaddr);
93
94 dma_free_coherent(q->dev, mem->size,
95 mem->vaddr, mem->dma_handle);
96 mem->vaddr = NULL;
97 }
98
99 q->bufs[i]->map = NULL;
100 q->bufs[i]->baddr = 0;
101 }
102
103 kfree(map);
104
97397687 105 videobuf_queue_unlock(q);
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106 }
107}
108
f0f37e2f 109static const struct vm_operations_struct videobuf_vm_ops = {
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110 .open = videobuf_vm_open,
111 .close = videobuf_vm_close,
112};
113
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114/**
115 * videobuf_dma_contig_user_put() - reset pointer to user space buffer
116 * @mem: per-buffer private videobuf-dma-contig data
117 *
118 * This function resets the user space pointer
119 */
120static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem)
121{
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122 mem->dma_handle = 0;
123 mem->size = 0;
124}
125
126/**
127 * videobuf_dma_contig_user_get() - setup user space memory pointer
128 * @mem: per-buffer private videobuf-dma-contig data
129 * @vb: video buffer to map
130 *
131 * This function validates and sets up a pointer to user space memory.
132 * Only physically contiguous pfn-mapped memory is accepted.
133 *
134 * Returns 0 if successful.
135 */
136static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem,
137 struct videobuf_buffer *vb)
138{
139 struct mm_struct *mm = current->mm;
140 struct vm_area_struct *vma;
141 unsigned long prev_pfn, this_pfn;
142 unsigned long pages_done, user_address;
31bedfa5 143 unsigned int offset;
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144 int ret;
145
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146 offset = vb->baddr & ~PAGE_MASK;
147 mem->size = PAGE_ALIGN(vb->size + offset);
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148 ret = -EINVAL;
149
150 down_read(&mm->mmap_sem);
151
152 vma = find_vma(mm, vb->baddr);
153 if (!vma)
154 goto out_up;
155
156 if ((vb->baddr + mem->size) > vma->vm_end)
157 goto out_up;
158
159 pages_done = 0;
160 prev_pfn = 0; /* kill warning */
161 user_address = vb->baddr;
162
163 while (pages_done < (mem->size >> PAGE_SHIFT)) {
164 ret = follow_pfn(vma, user_address, &this_pfn);
165 if (ret)
166 break;
167
168 if (pages_done == 0)
31bedfa5 169 mem->dma_handle = (this_pfn << PAGE_SHIFT) + offset;
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170 else if (this_pfn != (prev_pfn + 1))
171 ret = -EFAULT;
172
173 if (ret)
174 break;
175
176 prev_pfn = this_pfn;
177 user_address += PAGE_SIZE;
178 pages_done++;
179 }
180
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181 out_up:
182 up_read(&current->mm->mmap_sem);
183
184 return ret;
185}
186
33c38283 187static struct videobuf_buffer *__videobuf_alloc_vb(size_t size)
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188{
189 struct videobuf_dma_contig_memory *mem;
190 struct videobuf_buffer *vb;
191
192 vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
193 if (vb) {
194 mem = vb->priv = ((char *)vb) + size;
195 mem->magic = MAGIC_DC_MEM;
196 }
197
198 return vb;
199}
200
037c75eb 201static void *__videobuf_to_vaddr(struct videobuf_buffer *buf)
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202{
203 struct videobuf_dma_contig_memory *mem = buf->priv;
204
205 BUG_ON(!mem);
206 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
207
208 return mem->vaddr;
209}
210
211static int __videobuf_iolock(struct videobuf_queue *q,
212 struct videobuf_buffer *vb,
213 struct v4l2_framebuffer *fbuf)
214{
215 struct videobuf_dma_contig_memory *mem = vb->priv;
216
217 BUG_ON(!mem);
218 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
219
220 switch (vb->memory) {
221 case V4L2_MEMORY_MMAP:
222 dev_dbg(q->dev, "%s memory method MMAP\n", __func__);
223
224 /* All handling should be done by __videobuf_mmap_mapper() */
225 if (!mem->vaddr) {
226 dev_err(q->dev, "memory is not alloced/mmapped.\n");
227 return -EINVAL;
228 }
229 break;
230 case V4L2_MEMORY_USERPTR:
231 dev_dbg(q->dev, "%s memory method USERPTR\n", __func__);
232
720b17e7 233 /* handle pointer from user space */
2cc45cf2 234 if (vb->baddr)
720b17e7 235 return videobuf_dma_contig_user_get(mem, vb);
2cc45cf2 236
720b17e7 237 /* allocate memory for the read() method */
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238 mem->size = PAGE_ALIGN(vb->size);
239 mem->vaddr = dma_alloc_coherent(q->dev, mem->size,
240 &mem->dma_handle, GFP_KERNEL);
241 if (!mem->vaddr) {
242 dev_err(q->dev, "dma_alloc_coherent %ld failed\n",
243 mem->size);
244 return -ENOMEM;
245 }
246
247 dev_dbg(q->dev, "dma_alloc_coherent data is at %p (%ld)\n",
248 mem->vaddr, mem->size);
249 break;
250 case V4L2_MEMORY_OVERLAY:
251 default:
252 dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n",
253 __func__);
254 return -EINVAL;
255 }
256
257 return 0;
258}
259
2cc45cf2 260static int __videobuf_mmap_mapper(struct videobuf_queue *q,
0b62b737 261 struct videobuf_buffer *buf,
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262 struct vm_area_struct *vma)
263{
264 struct videobuf_dma_contig_memory *mem;
265 struct videobuf_mapping *map;
2cc45cf2 266 int retval;
0b62b737 267 unsigned long size;
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268
269 dev_dbg(q->dev, "%s\n", __func__);
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270
271 /* create mapping + update buffer list */
272 map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
273 if (!map)
274 return -ENOMEM;
275
0b62b737 276 buf->map = map;
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277 map->q = q;
278
0b62b737 279 buf->baddr = vma->vm_start;
2cc45cf2 280
0b62b737 281 mem = buf->priv;
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282 BUG_ON(!mem);
283 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
284
0b62b737 285 mem->size = PAGE_ALIGN(buf->bsize);
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286 mem->vaddr = dma_alloc_coherent(q->dev, mem->size,
287 &mem->dma_handle, GFP_KERNEL);
288 if (!mem->vaddr) {
289 dev_err(q->dev, "dma_alloc_coherent size %ld failed\n",
290 mem->size);
291 goto error;
292 }
293 dev_dbg(q->dev, "dma_alloc_coherent data is at addr %p (size %ld)\n",
294 mem->vaddr, mem->size);
295
296 /* Try to remap memory */
297
298 size = vma->vm_end - vma->vm_start;
299 size = (size < mem->size) ? size : mem->size;
300
301 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
302 retval = remap_pfn_range(vma, vma->vm_start,
71460af5 303 mem->dma_handle >> PAGE_SHIFT,
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304 size, vma->vm_page_prot);
305 if (retval) {
306 dev_err(q->dev, "mmap: remap failed with error %d. ", retval);
307 dma_free_coherent(q->dev, mem->size,
308 mem->vaddr, mem->dma_handle);
309 goto error;
310 }
311
312 vma->vm_ops = &videobuf_vm_ops;
313 vma->vm_flags |= VM_DONTEXPAND;
314 vma->vm_private_data = map;
315
316 dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
317 map, q, vma->vm_start, vma->vm_end,
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318 (long int)buf->bsize,
319 vma->vm_pgoff, buf->i);
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320
321 videobuf_vm_open(vma);
322
323 return 0;
324
325error:
326 kfree(map);
327 return -ENOMEM;
328}
329
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330static struct videobuf_qtype_ops qops = {
331 .magic = MAGIC_QTYPE_OPS,
332
33c38283 333 .alloc_vb = __videobuf_alloc_vb,
2cc45cf2 334 .iolock = __videobuf_iolock,
2cc45cf2 335 .mmap_mapper = __videobuf_mmap_mapper,
037c75eb 336 .vaddr = __videobuf_to_vaddr,
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337};
338
339void videobuf_queue_dma_contig_init(struct videobuf_queue *q,
38a54f35 340 const struct videobuf_queue_ops *ops,
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341 struct device *dev,
342 spinlock_t *irqlock,
343 enum v4l2_buf_type type,
344 enum v4l2_field field,
345 unsigned int msize,
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346 void *priv,
347 struct mutex *ext_lock)
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348{
349 videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
08bff03e 350 priv, &qops, ext_lock);
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351}
352EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init);
353
354dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf)
355{
356 struct videobuf_dma_contig_memory *mem = buf->priv;
357
358 BUG_ON(!mem);
359 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
360
361 return mem->dma_handle;
362}
363EXPORT_SYMBOL_GPL(videobuf_to_dma_contig);
364
365void videobuf_dma_contig_free(struct videobuf_queue *q,
366 struct videobuf_buffer *buf)
367{
368 struct videobuf_dma_contig_memory *mem = buf->priv;
369
370 /* mmapped memory can't be freed here, otherwise mmapped region
371 would be released, while still needed. In this case, the memory
372 release should happen inside videobuf_vm_close().
373 So, it should free memory only if the memory were allocated for
374 read() operation.
375 */
720b17e7 376 if (buf->memory != V4L2_MEMORY_USERPTR)
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377 return;
378
379 if (!mem)
380 return;
381
382 MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
383
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384 /* handle user space pointer case */
385 if (buf->baddr) {
386 videobuf_dma_contig_user_put(mem);
387 return;
388 }
389
390 /* read() method */
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391 if (mem->vaddr) {
392 dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle);
393 mem->vaddr = NULL;
394 }
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395}
396EXPORT_SYMBOL_GPL(videobuf_dma_contig_free);
397
398MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers");
399MODULE_AUTHOR("Magnus Damm");
400MODULE_LICENSE("GPL");