aboutsummaryrefslogtreecommitdiff
path: root/drivers/media/video/videobuf-vmalloc.c
blob: a868b7ed75ff2cc60f09181c1b1812dd44888c56 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
/*
 * helper functions for vmalloc video4linux capture buffers
 *
 * The functions expect the hardware being able to scatter gather
 * (i.e. the buffers are not linear in physical memory, but fragmented
 * into PAGE_SIZE chunks).  They also assume the driver does not need
 * to touch the video data.
 *
 * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/interrupt.h>

#include <linux/pci.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <asm/page.h>
#include <asm/pgtable.h>

#include <media/videobuf-vmalloc.h>

#define MAGIC_DMABUF   0x17760309
#define MAGIC_VMAL_MEM 0x18221223

#define MAGIC_CHECK(is,should)	if (unlikely((is) != (should))) \
	{ printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); }

static int debug;
module_param(debug, int, 0644);

MODULE_DESCRIPTION("helper module to manage video4linux vmalloc buffers");
MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
MODULE_LICENSE("GPL");

#define dprintk(level, fmt, arg...)	if (debug >= level) \
	printk(KERN_DEBUG "vbuf-vmalloc: " fmt , ## arg)


/***************************************************************************/

static void
videobuf_vm_open(struct vm_area_struct *vma)
{
	struct videobuf_mapping *map = vma->vm_private_data;

	dprintk(2,"vm_open %p [count=%u,vma=%08lx-%08lx]\n",map,
		map->count,vma->vm_start,vma->vm_end);

	map->count++;
}

static void videobuf_vm_close(struct vm_area_struct *vma)
{
	struct videobuf_mapping *map = vma->vm_private_data;
	struct videobuf_queue *q = map->q;
	int i;

	dprintk(2,"vm_close %p [count=%u,vma=%08lx-%08lx]\n", map,
		map->count, vma->vm_start, vma->vm_end);

	map->count--;
	if (0 == map->count) {
		struct videobuf_vmalloc_memory *mem;

		dprintk(1, "munmap %p q=%p\n", map, q);
		mutex_lock(&q->vb_lock);

		/* We need first to cancel streams, before unmapping */
		if (q->streaming)
			videobuf_queue_cancel(q);

		for (i = 0; i < VIDEO_MAX_FRAME; i++) {
			if (NULL == q->bufs[i])
				continue;

			if (q->bufs[i]->map != map)
				continue;

			mem = q->bufs[i]->priv;
			if (mem) {
				/* This callback is called only if kernel has
				   allocated memory and this memory is mmapped.
				   In this case, memory should be freed,
				   in order to do memory unmap.
				 */

				MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);

				/* vfree is not atomic - can't be
				   called with IRQ's disabled
				 */
				dprintk(1, "%s: buf[%d] freeing (%p)\n",
					__func__, i, mem->vmalloc);

				vfree(mem->vmalloc);
				mem->vmalloc = NULL;
			}

			q->bufs[i]->map   = NULL;
			q->bufs[i]->baddr = 0;
		}

		kfree(map);

		mutex_unlock(&q->vb_lock);
	}

	return;
}

static struct vm_operations_struct videobuf_vm_ops =
{
	.open     = videobuf_vm_open,
	.close    = videobuf_vm_close,
};

/* ---------------------------------------------------------------------
 * vmalloc handlers for the generic methods
 */

/* Allocated area consists on 3 parts:
	struct video_buffer
	struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
	struct videobuf_dma_sg_memory
 */

static void *__videobuf_alloc(size_t size)
{
	struct videobuf_vmalloc_memory *mem;
	struct videobuf_buffer *vb;

	vb = kzalloc(size+sizeof(*mem),GFP_KERNEL);

	mem = vb->priv = ((char *)vb)+size;
	mem->magic=MAGIC_VMAL_MEM;

	dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
		__func__,vb,(long)sizeof(*vb),(long)size-sizeof(*vb),
		mem,(long)sizeof(*mem));

	return vb;
}

static int __videobuf_iolock (struct videobuf_queue* q,
			      struct videobuf_buffer *vb,
			      struct v4l2_framebuffer *fbuf)
{
	struct videobuf_vmalloc_memory *mem = vb->priv;
	int pages;

	BUG_ON(!mem);

	MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);

	switch (vb->memory) {
	case V4L2_MEMORY_MMAP:
		dprintk(1, "%s memory method MMAP\n", __func__);

		/* All handling should be done by __videobuf_mmap_mapper() */
		if (!mem->vmalloc) {
			printk(KERN_ERR "memory is not alloced/mmapped.\n");
			return -EINVAL;
		}
		break;
	case V4L2_MEMORY_USERPTR:
		pages = PAGE_ALIGN(vb->size);

		dprintk(1, "%s memory method USERPTR\n", __func__);

#if 1
		if (vb->baddr) {
			printk(KERN_ERR "USERPTR is currently not supported\n");
			return -EINVAL;
		}
#endif

		/* The only USERPTR currently supported is the one needed for
		   read() method.
		 */

		mem->vmalloc = vmalloc_user(pages);
		if (!mem->vmalloc) {
			printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);
			return -ENOMEM;
		}
		dprintk(1, "vmalloc is at addr %p (%d pages)\n",
			mem->vmalloc, pages);

#if 0
		int rc;
		/* Kernel userptr is used also by read() method. In this case,
		   there's no need to remap, since data will be copied to user
		 */
		if (!vb->baddr)
			return 0;

		/* FIXME: to properly support USERPTR, remap should occur.
		   The code bellow won't work, since mem->vma = NULL
		 */
		/* Try to remap memory */
		rc = remap_vmalloc_range(mem->vma, (void *)vb->baddr, 0);
		if (rc < 0) {
			printk(KERN_ERR "mmap: remap failed with error %d. ", rc);
			return -ENOMEM;
		}
#endif

		break;
	case V4L2_MEMORY_OVERLAY:
	default:
		dprintk(1, "%s memory method OVERLAY/unknown\n", __func__);

		/* Currently, doesn't support V4L2_MEMORY_OVERLAY */
		printk(KERN_ERR "Memory method currently unsupported.\n");
		return -EINVAL;
	}

	return 0;
}

static int __videobuf_sync(struct videobuf_queue *q,
			   struct videobuf_buffer *buf)
{
	return 0;
}

static int __videobuf_mmap_free(struct videobuf_queue *q)
{
	unsigned int i;

	dprintk(1, "%s\n", __func__);
	for (i = 0; i < VIDEO_MAX_FRAME; i++) {
		if (q->bufs[i]) {
			if (q->bufs[i]->map)
				return -EBUSY;
		}
	}

	return 0;
}

static int __videobuf_mmap_mapper(struct videobuf_queue *q,
			 struct vm_area_struct *vma)
{
	struct videobuf_vmalloc_memory *mem;
	struct videobuf_mapping *map;
	unsigned int first;
	int retval, pages;
	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;

	dprintk(1, "%s\n", __func__);
	if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED))
		return -EINVAL;

	/* look for first buffer to map */
	for (first = 0; first < VIDEO_MAX_FRAME; first++) {
		if (NULL == q->bufs[first])
			continue;

		if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
			continue;
		if (q->bufs[first]->boff == offset)
			break;
	}
	if (VIDEO_MAX_FRAME == first) {
		dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n",
			(vma->vm_pgoff << PAGE_SHIFT));
		return -EINVAL;
	}

	/* create mapping + update buffer list */
	map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
	if (NULL == map)
		return -ENOMEM;

	q->bufs[first]->map = map;
	map->start = vma->vm_start;
	map->end   = vma->vm_end;
	map->q     = q;

	q->bufs[first]->baddr = vma->vm_start;

	mem = q->bufs[first]->priv;
	BUG_ON(!mem);
	MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);

	pages = PAGE_ALIGN(vma->vm_end - vma->vm_start);
	mem->vmalloc = vmalloc_user(pages);
	if (!mem->vmalloc) {
		printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);
		goto error;
	}
	dprintk(1, "vmalloc is at addr %p (%d pages)\n",
		mem->vmalloc, pages);

	/* Try to remap memory */
	retval = remap_vmalloc_range(vma, mem->vmalloc, 0);
	if (retval < 0) {
		printk(KERN_ERR "mmap: remap failed with error %d. ", retval);
		vfree(mem->vmalloc);
		goto error;
	}

	vma->vm_ops          = &videobuf_vm_ops;
	vma->vm_flags       |= VM_DONTEXPAND | VM_RESERVED;
	vma->vm_private_data = map;

	dprintk(1,"mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
		map, q, vma->vm_start, vma->vm_end,
		(long int) q->bufs[first]->bsize,
		vma->vm_pgoff, first);

	videobuf_vm_open(vma);

	return 0;

error:
	mem = NULL;
	kfree(map);
	return -ENOMEM;
}

static int __videobuf_copy_to_user ( struct videobuf_queue *q,
				char __user *data, size_t count,
				int nonblocking )
{
	struct videobuf_vmalloc_memory *mem=q->read_buf->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

	BUG_ON (!mem->vmalloc);

	/* copy to userspace */
	if (count > q->read_buf->size - q->read_off)
		count = q->read_buf->size - q->read_off;

	if (copy_to_user(data, mem->vmalloc+q->read_off, count))
		return -EFAULT;

	return count;
}

static int __videobuf_copy_stream ( struct videobuf_queue *q,
				char __user *data, size_t count, size_t pos,
				int vbihack, int nonblocking )
{
	unsigned int  *fc;
	struct videobuf_vmalloc_memory *mem=q->read_buf->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

	if (vbihack) {
		/* dirty, undocumented hack -- pass the frame counter
			* within the last four bytes of each vbi data block.
			* We need that one to maintain backward compatibility
			* to all vbi decoding software out there ... */
		fc  = (unsigned int*)mem->vmalloc;
		fc += (q->read_buf->size>>2) -1;
		*fc = q->read_buf->field_count >> 1;
		dprintk(1,"vbihack: %d\n",*fc);
	}

	/* copy stuff using the common method */
	count = __videobuf_copy_to_user (q,data,count,nonblocking);

	if ( (count==-EFAULT) && (0 == pos) )
		return -EFAULT;

	return count;
}

static struct videobuf_qtype_ops qops = {
	.magic        = MAGIC_QTYPE_OPS,

	.alloc        = __videobuf_alloc,
	.iolock       = __videobuf_iolock,
	.sync         = __videobuf_sync,
	.mmap_free    = __videobuf_mmap_free,
	.mmap_mapper  = __videobuf_mmap_mapper,
	.video_copy_to_user = __videobuf_copy_to_user,
	.copy_stream  = __videobuf_copy_stream,
	.vmalloc      = videobuf_to_vmalloc,
};

void videobuf_queue_vmalloc_init(struct videobuf_queue* q,
			 struct videobuf_queue_ops *ops,
			 void *dev,
			 spinlock_t *irqlock,
			 enum v4l2_buf_type type,
			 enum v4l2_field field,
			 unsigned int msize,
			 void *priv)
{
	videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
				 priv, &qops);
}

EXPORT_SYMBOL_GPL(videobuf_queue_vmalloc_init);

void *videobuf_to_vmalloc (struct videobuf_buffer *buf)
{
	struct videobuf_vmalloc_memory *mem=buf->priv;
	BUG_ON (!mem);
	MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);

	return mem->vmalloc;
}
EXPORT_SYMBOL_GPL(videobuf_to_vmalloc);

void videobuf_vmalloc_free (struct videobuf_buffer *buf)
{
	struct videobuf_vmalloc_memory *mem = buf->priv;

	/* mmapped memory can't be freed here, otherwise mmapped region
	   would be released, while still needed. In this case, the memory
	   release should happen inside videobuf_vm_close().
	   So, it should free memory only if the memory were allocated for
	   read() operation.
	 */
	if ((buf->memory != V4L2_MEMORY_USERPTR) || (buf->baddr == 0))
		return;

	if (!mem)
		return;

	MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);

	vfree(mem->vmalloc);
	mem->vmalloc = NULL;

	return;
}
EXPORT_SYMBOL_GPL(videobuf_vmalloc_free);

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */