1 /*
2 * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 *
6 * Author: Pawel Osciak <pawel@osciak.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation.
11 */
12
13 #include <linux/io.h>
14 #include <linux/module.h>
15 #include <linux/mm.h>
16 #include <linux/refcount.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/vmalloc.h>
20
21 #include <media/videobuf2-v4l2.h>
22 #include <media/videobuf2-vmalloc.h>
23 #include <media/videobuf2-memops.h>
24
25 struct vb2_vmalloc_buf {
26 void *vaddr;
27 struct frame_vector *vec;
28 enum dma_data_direction dma_dir;
29 unsigned long size;
30 refcount_t refcount;
31 struct vb2_vmarea_handler handler;
32 struct dma_buf *dbuf;
33 };
34
35 static void vb2_vmalloc_put(void *buf_priv);
36
vb2_vmalloc_alloc(struct device * dev,unsigned long attrs,unsigned long size,enum dma_data_direction dma_dir,gfp_t gfp_flags)37 static void *vb2_vmalloc_alloc(struct device *dev, unsigned long attrs,
38 unsigned long size, enum dma_data_direction dma_dir,
39 gfp_t gfp_flags)
40 {
41 struct vb2_vmalloc_buf *buf;
42
43 buf = kzalloc(sizeof(*buf), GFP_KERNEL | gfp_flags);
44 if (!buf)
45 return ERR_PTR(-ENOMEM);
46
47 buf->size = size;
48 buf->vaddr = vmalloc_user(buf->size);
49 if (!buf->vaddr) {
50 pr_debug("vmalloc of size %ld failed\n", buf->size);
51 kfree(buf);
52 return ERR_PTR(-ENOMEM);
53 }
54
55 buf->dma_dir = dma_dir;
56 buf->handler.refcount = &buf->refcount;
57 buf->handler.put = vb2_vmalloc_put;
58 buf->handler.arg = buf;
59
60 refcount_set(&buf->refcount, 1);
61 return buf;
62 }
63
vb2_vmalloc_put(void * buf_priv)64 static void vb2_vmalloc_put(void *buf_priv)
65 {
66 struct vb2_vmalloc_buf *buf = buf_priv;
67
68 if (refcount_dec_and_test(&buf->refcount)) {
69 vfree(buf->vaddr);
70 kfree(buf);
71 }
72 }
73
vb2_vmalloc_get_userptr(struct device * dev,unsigned long vaddr,unsigned long size,enum dma_data_direction dma_dir)74 static void *vb2_vmalloc_get_userptr(struct device *dev, unsigned long vaddr,
75 unsigned long size,
76 enum dma_data_direction dma_dir)
77 {
78 struct vb2_vmalloc_buf *buf;
79 struct frame_vector *vec;
80 int n_pages, offset, i;
81 int ret = -ENOMEM;
82
83 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
84 if (!buf)
85 return ERR_PTR(-ENOMEM);
86
87 buf->dma_dir = dma_dir;
88 offset = vaddr & ~PAGE_MASK;
89 buf->size = size;
90 vec = vb2_create_framevec(vaddr, size);
91 if (IS_ERR(vec)) {
92 ret = PTR_ERR(vec);
93 goto fail_pfnvec_create;
94 }
95 buf->vec = vec;
96 n_pages = frame_vector_count(vec);
97 if (frame_vector_to_pages(vec) < 0) {
98 unsigned long *nums = frame_vector_pfns(vec);
99
100 /*
101 * We cannot get page pointers for these pfns. Check memory is
102 * physically contiguous and use direct mapping.
103 */
104 for (i = 1; i < n_pages; i++)
105 if (nums[i-1] + 1 != nums[i])
106 goto fail_map;
107 buf->vaddr = (__force void *)
108 ioremap_nocache(__pfn_to_phys(nums[0]), size + offset);
109 } else {
110 buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1,
111 PAGE_KERNEL);
112 }
113
114 if (!buf->vaddr)
115 goto fail_map;
116 buf->vaddr += offset;
117 return buf;
118
119 fail_map:
120 vb2_destroy_framevec(vec);
121 fail_pfnvec_create:
122 kfree(buf);
123
124 return ERR_PTR(ret);
125 }
126
vb2_vmalloc_put_userptr(void * buf_priv)127 static void vb2_vmalloc_put_userptr(void *buf_priv)
128 {
129 struct vb2_vmalloc_buf *buf = buf_priv;
130 unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
131 unsigned int i;
132 struct page **pages;
133 unsigned int n_pages;
134
135 if (!buf->vec->is_pfns) {
136 n_pages = frame_vector_count(buf->vec);
137 pages = frame_vector_pages(buf->vec);
138 if (vaddr)
139 vm_unmap_ram((void *)vaddr, n_pages);
140 if (buf->dma_dir == DMA_FROM_DEVICE ||
141 buf->dma_dir == DMA_BIDIRECTIONAL)
142 for (i = 0; i < n_pages; i++)
143 set_page_dirty_lock(pages[i]);
144 } else {
145 iounmap((__force void __iomem *)buf->vaddr);
146 }
147 vb2_destroy_framevec(buf->vec);
148 kfree(buf);
149 }
150
vb2_vmalloc_vaddr(void * buf_priv)151 static void *vb2_vmalloc_vaddr(void *buf_priv)
152 {
153 struct vb2_vmalloc_buf *buf = buf_priv;
154
155 if (!buf->vaddr) {
156 pr_err("Address of an unallocated plane requested or cannot map user pointer\n");
157 return NULL;
158 }
159
160 return buf->vaddr;
161 }
162
vb2_vmalloc_num_users(void * buf_priv)163 static unsigned int vb2_vmalloc_num_users(void *buf_priv)
164 {
165 struct vb2_vmalloc_buf *buf = buf_priv;
166 return refcount_read(&buf->refcount);
167 }
168
vb2_vmalloc_mmap(void * buf_priv,struct vm_area_struct * vma)169 static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
170 {
171 struct vb2_vmalloc_buf *buf = buf_priv;
172 int ret;
173
174 if (!buf) {
175 pr_err("No memory to map\n");
176 return -EINVAL;
177 }
178
179 ret = remap_vmalloc_range(vma, buf->vaddr, 0);
180 if (ret) {
181 pr_err("Remapping vmalloc memory, error: %d\n", ret);
182 return ret;
183 }
184
185 /*
186 * Make sure that vm_areas for 2 buffers won't be merged together
187 */
188 vma->vm_flags |= VM_DONTEXPAND;
189
190 /*
191 * Use common vm_area operations to track buffer refcount.
192 */
193 vma->vm_private_data = &buf->handler;
194 vma->vm_ops = &vb2_common_vm_ops;
195
196 vma->vm_ops->open(vma);
197
198 return 0;
199 }
200
201 #ifdef CONFIG_HAS_DMA
202 /*********************************************/
203 /* DMABUF ops for exporters */
204 /*********************************************/
205
206 struct vb2_vmalloc_attachment {
207 struct sg_table sgt;
208 enum dma_data_direction dma_dir;
209 };
210
vb2_vmalloc_dmabuf_ops_attach(struct dma_buf * dbuf,struct dma_buf_attachment * dbuf_attach)211 static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf,
212 struct dma_buf_attachment *dbuf_attach)
213 {
214 struct vb2_vmalloc_attachment *attach;
215 struct vb2_vmalloc_buf *buf = dbuf->priv;
216 int num_pages = PAGE_ALIGN(buf->size) / PAGE_SIZE;
217 struct sg_table *sgt;
218 struct scatterlist *sg;
219 void *vaddr = buf->vaddr;
220 int ret;
221 int i;
222
223 attach = kzalloc(sizeof(*attach), GFP_KERNEL);
224 if (!attach)
225 return -ENOMEM;
226
227 sgt = &attach->sgt;
228 ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL);
229 if (ret) {
230 kfree(attach);
231 return ret;
232 }
233 for_each_sg(sgt->sgl, sg, sgt->nents, i) {
234 struct page *page = vmalloc_to_page(vaddr);
235
236 if (!page) {
237 sg_free_table(sgt);
238 kfree(attach);
239 return -ENOMEM;
240 }
241 sg_set_page(sg, page, PAGE_SIZE, 0);
242 vaddr += PAGE_SIZE;
243 }
244
245 attach->dma_dir = DMA_NONE;
246 dbuf_attach->priv = attach;
247 return 0;
248 }
249
vb2_vmalloc_dmabuf_ops_detach(struct dma_buf * dbuf,struct dma_buf_attachment * db_attach)250 static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf,
251 struct dma_buf_attachment *db_attach)
252 {
253 struct vb2_vmalloc_attachment *attach = db_attach->priv;
254 struct sg_table *sgt;
255
256 if (!attach)
257 return;
258
259 sgt = &attach->sgt;
260
261 /* release the scatterlist cache */
262 if (attach->dma_dir != DMA_NONE)
263 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
264 attach->dma_dir);
265 sg_free_table(sgt);
266 kfree(attach);
267 db_attach->priv = NULL;
268 }
269
vb2_vmalloc_dmabuf_ops_map(struct dma_buf_attachment * db_attach,enum dma_data_direction dma_dir)270 static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
271 struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
272 {
273 struct vb2_vmalloc_attachment *attach = db_attach->priv;
274 /* stealing dmabuf mutex to serialize map/unmap operations */
275 struct mutex *lock = &db_attach->dmabuf->lock;
276 struct sg_table *sgt;
277
278 mutex_lock(lock);
279
280 sgt = &attach->sgt;
281 /* return previously mapped sg table */
282 if (attach->dma_dir == dma_dir) {
283 mutex_unlock(lock);
284 return sgt;
285 }
286
287 /* release any previous cache */
288 if (attach->dma_dir != DMA_NONE) {
289 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
290 attach->dma_dir);
291 attach->dma_dir = DMA_NONE;
292 }
293
294 /* mapping to the client with new direction */
295 sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
296 dma_dir);
297 if (!sgt->nents) {
298 pr_err("failed to map scatterlist\n");
299 mutex_unlock(lock);
300 return ERR_PTR(-EIO);
301 }
302
303 attach->dma_dir = dma_dir;
304
305 mutex_unlock(lock);
306
307 return sgt;
308 }
309
vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment * db_attach,struct sg_table * sgt,enum dma_data_direction dma_dir)310 static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
311 struct sg_table *sgt, enum dma_data_direction dma_dir)
312 {
313 /* nothing to be done here */
314 }
315
vb2_vmalloc_dmabuf_ops_release(struct dma_buf * dbuf)316 static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf)
317 {
318 /* drop reference obtained in vb2_vmalloc_get_dmabuf */
319 vb2_vmalloc_put(dbuf->priv);
320 }
321
vb2_vmalloc_dmabuf_ops_kmap(struct dma_buf * dbuf,unsigned long pgnum)322 static void *vb2_vmalloc_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
323 {
324 struct vb2_vmalloc_buf *buf = dbuf->priv;
325
326 return buf->vaddr + pgnum * PAGE_SIZE;
327 }
328
vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf * dbuf)329 static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf)
330 {
331 struct vb2_vmalloc_buf *buf = dbuf->priv;
332
333 return buf->vaddr;
334 }
335
vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf * dbuf,struct vm_area_struct * vma)336 static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf,
337 struct vm_area_struct *vma)
338 {
339 return vb2_vmalloc_mmap(dbuf->priv, vma);
340 }
341
342 static const struct dma_buf_ops vb2_vmalloc_dmabuf_ops = {
343 .attach = vb2_vmalloc_dmabuf_ops_attach,
344 .detach = vb2_vmalloc_dmabuf_ops_detach,
345 .map_dma_buf = vb2_vmalloc_dmabuf_ops_map,
346 .unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap,
347 .map = vb2_vmalloc_dmabuf_ops_kmap,
348 .vmap = vb2_vmalloc_dmabuf_ops_vmap,
349 .mmap = vb2_vmalloc_dmabuf_ops_mmap,
350 .release = vb2_vmalloc_dmabuf_ops_release,
351 };
352
vb2_vmalloc_get_dmabuf(void * buf_priv,unsigned long flags)353 static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags)
354 {
355 struct vb2_vmalloc_buf *buf = buf_priv;
356 struct dma_buf *dbuf;
357 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
358
359 exp_info.ops = &vb2_vmalloc_dmabuf_ops;
360 exp_info.size = buf->size;
361 exp_info.flags = flags;
362 exp_info.priv = buf;
363
364 if (WARN_ON(!buf->vaddr))
365 return NULL;
366
367 dbuf = dma_buf_export(&exp_info);
368 if (IS_ERR(dbuf))
369 return NULL;
370
371 /* dmabuf keeps reference to vb2 buffer */
372 refcount_inc(&buf->refcount);
373
374 return dbuf;
375 }
376 #endif /* CONFIG_HAS_DMA */
377
378
379 /*********************************************/
380 /* callbacks for DMABUF buffers */
381 /*********************************************/
382
vb2_vmalloc_map_dmabuf(void * mem_priv)383 static int vb2_vmalloc_map_dmabuf(void *mem_priv)
384 {
385 struct vb2_vmalloc_buf *buf = mem_priv;
386
387 buf->vaddr = dma_buf_vmap(buf->dbuf);
388
389 return buf->vaddr ? 0 : -EFAULT;
390 }
391
vb2_vmalloc_unmap_dmabuf(void * mem_priv)392 static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
393 {
394 struct vb2_vmalloc_buf *buf = mem_priv;
395
396 dma_buf_vunmap(buf->dbuf, buf->vaddr);
397 buf->vaddr = NULL;
398 }
399
vb2_vmalloc_detach_dmabuf(void * mem_priv)400 static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
401 {
402 struct vb2_vmalloc_buf *buf = mem_priv;
403
404 if (buf->vaddr)
405 dma_buf_vunmap(buf->dbuf, buf->vaddr);
406
407 kfree(buf);
408 }
409
vb2_vmalloc_attach_dmabuf(struct device * dev,struct dma_buf * dbuf,unsigned long size,enum dma_data_direction dma_dir)410 static void *vb2_vmalloc_attach_dmabuf(struct device *dev, struct dma_buf *dbuf,
411 unsigned long size, enum dma_data_direction dma_dir)
412 {
413 struct vb2_vmalloc_buf *buf;
414
415 if (dbuf->size < size)
416 return ERR_PTR(-EFAULT);
417
418 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
419 if (!buf)
420 return ERR_PTR(-ENOMEM);
421
422 buf->dbuf = dbuf;
423 buf->dma_dir = dma_dir;
424 buf->size = size;
425
426 return buf;
427 }
428
429
430 const struct vb2_mem_ops vb2_vmalloc_memops = {
431 .alloc = vb2_vmalloc_alloc,
432 .put = vb2_vmalloc_put,
433 .get_userptr = vb2_vmalloc_get_userptr,
434 .put_userptr = vb2_vmalloc_put_userptr,
435 #ifdef CONFIG_HAS_DMA
436 .get_dmabuf = vb2_vmalloc_get_dmabuf,
437 #endif
438 .map_dmabuf = vb2_vmalloc_map_dmabuf,
439 .unmap_dmabuf = vb2_vmalloc_unmap_dmabuf,
440 .attach_dmabuf = vb2_vmalloc_attach_dmabuf,
441 .detach_dmabuf = vb2_vmalloc_detach_dmabuf,
442 .vaddr = vb2_vmalloc_vaddr,
443 .mmap = vb2_vmalloc_mmap,
444 .num_users = vb2_vmalloc_num_users,
445 };
446 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
447
448 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
449 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
450 MODULE_LICENSE("GPL");
451
